tpm2-util: do not serialize tpm2 bank if none is specified

[thirdparty/systemd.git] / src / shared / tpm2-util.c

/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <sys/file.h>

#include "alloc-util.h"
#include "constants.h"
#include "creds-util.h"
#include "cryptsetup-util.h"
#include "dirent-util.h"
#include "dlfcn-util.h"
#include "efi-api.h"
#include "extract-word.h"
#include "fd-util.h"
#include "fileio.h"
#include "format-table.h"
#include "fs-util.h"
#include "hexdecoct.h"
#include "hmac.h"
#include "initrd-util.h"
#include "io-util.h"
#include "lock-util.h"
#include "log.h"
#include "logarithm.h"
#include "memory-util.h"
#include "mkdir.h"
#include "nulstr-util.h"
#include "parse-util.h"
#include "random-util.h"
#include "recurse-dir.h"
#include "sha256.h"
#include "sort-util.h"
#include "sparse-endian.h"
#include "stat-util.h"
#include "string-table.h"
#include "sync-util.h"
#include "time-util.h"
#include "tpm2-util.h"
#include "virt.h"

#if HAVE_OPENSSL
#  include <openssl/hmac.h>
#endif

#if HAVE_TPM2
static void *libtss2_esys_dl = NULL;
static void *libtss2_rc_dl = NULL;
static void *libtss2_mu_dl = NULL;

static DLSYM_FUNCTION(Esys_Create);
static DLSYM_FUNCTION(Esys_CreateLoaded);
static DLSYM_FUNCTION(Esys_CreatePrimary);
static DLSYM_FUNCTION(Esys_EvictControl);
static DLSYM_FUNCTION(Esys_Finalize);
static DLSYM_FUNCTION(Esys_FlushContext);
static DLSYM_FUNCTION(Esys_Free);
static DLSYM_FUNCTION(Esys_GetCapability);
static DLSYM_FUNCTION(Esys_GetRandom);
static DLSYM_FUNCTION(Esys_Import);
static DLSYM_FUNCTION(Esys_Initialize);
static DLSYM_FUNCTION(Esys_Load);
static DLSYM_FUNCTION(Esys_LoadExternal);
static DLSYM_FUNCTION(Esys_NV_DefineSpace);
static DLSYM_FUNCTION(Esys_NV_UndefineSpace);
static DLSYM_FUNCTION(Esys_NV_Write);
static DLSYM_FUNCTION(Esys_PCR_Extend);
static DLSYM_FUNCTION(Esys_PCR_Read);
static DLSYM_FUNCTION(Esys_PolicyAuthValue);
static DLSYM_FUNCTION(Esys_PolicyAuthorize);
static DLSYM_FUNCTION(Esys_PolicyAuthorizeNV);
static DLSYM_FUNCTION(Esys_PolicyGetDigest);
static DLSYM_FUNCTION(Esys_PolicyOR);
static DLSYM_FUNCTION(Esys_PolicyPCR);
static DLSYM_FUNCTION(Esys_PolicySigned);
static DLSYM_FUNCTION(Esys_ReadPublic);
static DLSYM_FUNCTION(Esys_StartAuthSession);
static DLSYM_FUNCTION(Esys_Startup);
static DLSYM_FUNCTION(Esys_TestParms);
static DLSYM_FUNCTION(Esys_TR_Close);
static DLSYM_FUNCTION(Esys_TR_Deserialize);
static DLSYM_FUNCTION(Esys_TR_FromTPMPublic);
static DLSYM_FUNCTION(Esys_TR_GetName);
static DLSYM_FUNCTION(Esys_TR_GetTpmHandle);
static DLSYM_FUNCTION(Esys_TR_Serialize);
static DLSYM_FUNCTION(Esys_TR_SetAuth);
static DLSYM_FUNCTION(Esys_TRSess_GetAttributes);
static DLSYM_FUNCTION(Esys_TRSess_GetNonceTPM);
static DLSYM_FUNCTION(Esys_TRSess_SetAttributes);
static DLSYM_FUNCTION(Esys_Unseal);
static DLSYM_FUNCTION(Esys_VerifySignature);

static DLSYM_FUNCTION(Tss2_MU_TPM2_CC_Marshal);
static DLSYM_FUNCTION(Tss2_MU_TPM2_HANDLE_Marshal);
static DLSYM_FUNCTION(Tss2_MU_TPM2B_DIGEST_Marshal);
static DLSYM_FUNCTION(Tss2_MU_TPM2B_ENCRYPTED_SECRET_Marshal);
static DLSYM_FUNCTION(Tss2_MU_TPM2B_ENCRYPTED_SECRET_Unmarshal);
static DLSYM_FUNCTION(Tss2_MU_TPM2B_NAME_Marshal);
static DLSYM_FUNCTION(Tss2_MU_TPM2B_PRIVATE_Marshal);
static DLSYM_FUNCTION(Tss2_MU_TPM2B_PRIVATE_Unmarshal);
static DLSYM_FUNCTION(Tss2_MU_TPM2B_PUBLIC_Marshal);
static DLSYM_FUNCTION(Tss2_MU_TPM2B_PUBLIC_Unmarshal);
static DLSYM_FUNCTION(Tss2_MU_TPM2B_SENSITIVE_Marshal);
static DLSYM_FUNCTION(Tss2_MU_TPML_PCR_SELECTION_Marshal);
static DLSYM_FUNCTION(Tss2_MU_TPMS_NV_PUBLIC_Marshal);
static DLSYM_FUNCTION(Tss2_MU_TPM2B_NV_PUBLIC_Marshal);
static DLSYM_FUNCTION(Tss2_MU_TPM2B_NV_PUBLIC_Unmarshal);
static DLSYM_FUNCTION(Tss2_MU_TPMS_ECC_POINT_Marshal);
static DLSYM_FUNCTION(Tss2_MU_TPMT_HA_Marshal);
static DLSYM_FUNCTION(Tss2_MU_TPMT_PUBLIC_Marshal);
static DLSYM_FUNCTION(Tss2_MU_UINT32_Marshal);

static DLSYM_FUNCTION(Tss2_RC_Decode);

int dlopen_tpm2(void) {
        int r;

        ELF_NOTE_DLOPEN("tpm",
                        "Support for TPM",
                        ELF_NOTE_DLOPEN_PRIORITY_SUGGESTED,
                        "libtss2-esys.so.0");

        r = dlopen_many_sym_or_warn(
                        &libtss2_esys_dl, "libtss2-esys.so.0", LOG_DEBUG,
                        DLSYM_ARG(Esys_Create),
                        DLSYM_ARG(Esys_CreateLoaded),
                        DLSYM_ARG(Esys_CreatePrimary),
                        DLSYM_ARG(Esys_EvictControl),
                        DLSYM_ARG(Esys_Finalize),
                        DLSYM_ARG(Esys_FlushContext),
                        DLSYM_ARG(Esys_Free),
                        DLSYM_ARG(Esys_GetCapability),
                        DLSYM_ARG(Esys_GetRandom),
                        DLSYM_ARG(Esys_Import),
                        DLSYM_ARG(Esys_Initialize),
                        DLSYM_ARG(Esys_Load),
                        DLSYM_ARG(Esys_LoadExternal),
                        DLSYM_ARG(Esys_NV_DefineSpace),
                        DLSYM_ARG(Esys_NV_UndefineSpace),
                        DLSYM_ARG(Esys_NV_Write),
                        DLSYM_ARG(Esys_PCR_Extend),
                        DLSYM_ARG(Esys_PCR_Read),
                        DLSYM_ARG(Esys_PolicyAuthValue),
                        DLSYM_ARG(Esys_PolicyAuthorize),
                        DLSYM_ARG(Esys_PolicyAuthorizeNV),
                        DLSYM_ARG(Esys_PolicyGetDigest),
                        DLSYM_ARG(Esys_PolicyOR),
                        DLSYM_ARG(Esys_PolicyPCR),
                        DLSYM_ARG(Esys_PolicySigned),
                        DLSYM_ARG(Esys_ReadPublic),
                        DLSYM_ARG(Esys_StartAuthSession),
                        DLSYM_ARG(Esys_Startup),
                        DLSYM_ARG(Esys_TestParms),
                        DLSYM_ARG(Esys_TR_Close),
                        DLSYM_ARG(Esys_TR_Deserialize),
                        DLSYM_ARG(Esys_TR_FromTPMPublic),
                        DLSYM_ARG(Esys_TR_GetName),
                        DLSYM_ARG(Esys_TR_Serialize),
                        DLSYM_ARG(Esys_TR_SetAuth),
                        DLSYM_ARG(Esys_TRSess_GetAttributes),
                        DLSYM_ARG(Esys_TRSess_GetNonceTPM),
                        DLSYM_ARG(Esys_TRSess_SetAttributes),
                        DLSYM_ARG(Esys_Unseal),
                        DLSYM_ARG(Esys_VerifySignature));
        if (r < 0)
                return r;

        /* Esys_TR_GetTpmHandle was added to tpm2-tss in version 2.4.0. Once we can set a minimum tpm2-tss
         * version of 2.4.0 this sym can be moved up to the normal list above. */
        r = dlsym_many_or_warn(libtss2_esys_dl, LOG_DEBUG, DLSYM_ARG_FORCE(Esys_TR_GetTpmHandle));
        if (r < 0)
                log_debug("libtss2-esys too old, does not include Esys_TR_GetTpmHandle.");

        ELF_NOTE_DLOPEN("tpm",
                        "Support for TPM",
                        ELF_NOTE_DLOPEN_PRIORITY_SUGGESTED,
                        "libtss2-rc.so.0");

        r = dlopen_many_sym_or_warn(
                        &libtss2_rc_dl, "libtss2-rc.so.0", LOG_DEBUG,
                        DLSYM_ARG(Tss2_RC_Decode));
        if (r < 0)
                return r;

        ELF_NOTE_DLOPEN("tpm",
                        "Support for TPM",
                        ELF_NOTE_DLOPEN_PRIORITY_SUGGESTED,
                        "libtss2-mu.so.0");

        return dlopen_many_sym_or_warn(
                        &libtss2_mu_dl, "libtss2-mu.so.0", LOG_DEBUG,
                        DLSYM_ARG(Tss2_MU_TPM2_CC_Marshal),
                        DLSYM_ARG(Tss2_MU_TPM2_HANDLE_Marshal),
                        DLSYM_ARG(Tss2_MU_TPM2B_DIGEST_Marshal),
                        DLSYM_ARG(Tss2_MU_TPM2B_ENCRYPTED_SECRET_Marshal),
                        DLSYM_ARG(Tss2_MU_TPM2B_ENCRYPTED_SECRET_Unmarshal),
                        DLSYM_ARG(Tss2_MU_TPM2B_NAME_Marshal),
                        DLSYM_ARG(Tss2_MU_TPM2B_PRIVATE_Marshal),
                        DLSYM_ARG(Tss2_MU_TPM2B_PRIVATE_Unmarshal),
                        DLSYM_ARG(Tss2_MU_TPM2B_PUBLIC_Marshal),
                        DLSYM_ARG(Tss2_MU_TPM2B_PUBLIC_Unmarshal),
                        DLSYM_ARG(Tss2_MU_TPM2B_SENSITIVE_Marshal),
                        DLSYM_ARG(Tss2_MU_TPML_PCR_SELECTION_Marshal),
                        DLSYM_ARG(Tss2_MU_TPMS_NV_PUBLIC_Marshal),
                        DLSYM_ARG(Tss2_MU_TPM2B_NV_PUBLIC_Marshal),
                        DLSYM_ARG(Tss2_MU_TPM2B_NV_PUBLIC_Unmarshal),
                        DLSYM_ARG(Tss2_MU_TPMS_ECC_POINT_Marshal),
                        DLSYM_ARG(Tss2_MU_TPMT_HA_Marshal),
                        DLSYM_ARG(Tss2_MU_TPMT_PUBLIC_Marshal),
                        DLSYM_ARG(Tss2_MU_UINT32_Marshal));
}

void Esys_Freep(void *p) {
        if (*(void**) p)
                sym_Esys_Free(*(void**) p);
}

/* Get a specific TPM capability (or capabilities).
 *
 * Returns 0 if there are no more capability properties of the requested type, or 1 if there are more, or < 0
 * on any error. Both 0 and 1 indicate this completed successfully, but do not indicate how many capability
 * properties were provided in 'ret_capability_data'. To find the number of provided properties, check the
 * specific type's 'count' field (e.g. for TPM2_CAP_ALGS, check ret_capability_data->algorithms.count).
 *
 * This calls TPM2_GetCapability() and does not alter the provided data, so it is important to understand how
 * that TPM function works. It is recommended to check the TCG TPM specification Part 3 ("Commands") section
 * on TPM2_GetCapability() for full details, but a short summary is: if this returns 0, all available
 * properties have been provided in ret_capability_data, or no properties were available. If this returns 1,
 * there are between 1 and "count" properties provided in ret_capability_data, and there are more available.
 * Note that this may provide less than "count" properties even if the TPM has more available. Also, each
 * capability category may have more specific requirements than described here; see the spec for exact
 * details. */
static int tpm2_get_capability(
                Tpm2Context *c,
                TPM2_CAP capability,
                uint32_t property,
                uint32_t count,
                TPMU_CAPABILITIES *ret_capability_data) {

        _cleanup_(Esys_Freep) TPMS_CAPABILITY_DATA *capabilities = NULL;
        TPMI_YES_NO more;
        TSS2_RC rc;

        assert(c);

        log_debug("Getting TPM2 capability 0x%04" PRIx32 " property 0x%04" PRIx32 " count %" PRIu32 ".",
                  capability, property, count);

        rc = sym_Esys_GetCapability(
                        c->esys_context,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        capability,
                        property,
                        count,
                        &more,
                        &capabilities);
        if (rc == TPM2_RC_VALUE)
                return log_debug_errno(SYNTHETIC_ERRNO(ENXIO),
                                       "Requested TPM2 capability 0x%04" PRIx32 " property 0x%04" PRIx32 " apparently doesn't exist: %s",
                                       capability, property, sym_Tss2_RC_Decode(rc));
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to get TPM2 capability 0x%04" PRIx32 " property 0x%04" PRIx32 ": %s",
                                       capability, property, sym_Tss2_RC_Decode(rc));
        if (capabilities->capability != capability)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "TPM provided wrong capability: 0x%04" PRIx32 " instead of 0x%04" PRIx32 ".",
                                       capabilities->capability, capability);

        if (ret_capability_data)
                *ret_capability_data = capabilities->data;

        return more == TPM2_YES;
}

#define TPMA_CC_TO_TPM2_CC(cca) (((cca) & TPMA_CC_COMMANDINDEX_MASK) >> TPMA_CC_COMMANDINDEX_SHIFT)

static int tpm2_cache_capabilities(Tpm2Context *c) {
        TPMU_CAPABILITIES capability;
        int r;

        assert(c);

        /* Cache the algorithms. The spec indicates supported algorithms can only be modified during runtime
         * by the SetAlgorithmSet() command. Unfortunately, the spec doesn't require a TPM reinitialization
         * after changing the algorithm set (unless the PCR algorithms are changed). However, the spec also
         * indicates the TPM behavior after SetAlgorithmSet() is "vendor-dependent", giving the example of
         * flushing sessions and objects, erasing policies, etc. So, if the algorithm set is programmatically
         * changed while we are performing some operation, it's reasonable to assume it will break us even if
         * we don't cache the algorithms, thus they should be "safe" to cache. */
        TPM2_ALG_ID current_alg = TPM2_ALG_FIRST;
        for (;;) {
                r = tpm2_get_capability(
                                c,
                                TPM2_CAP_ALGS,
                                (uint32_t) current_alg, /* The spec states to cast TPM2_ALG_ID to uint32_t. */
                                TPM2_MAX_CAP_ALGS,
                                &capability);
                if (r < 0)
                        return r;

                TPML_ALG_PROPERTY algorithms = capability.algorithms;

                /* We should never get 0; the TPM must support some algorithms, and it must not set 'more' if
                 * there are no more. */
                assert(algorithms.count > 0);

                if (!GREEDY_REALLOC_APPEND(
                                c->capability_algorithms,
                                c->n_capability_algorithms,
                                algorithms.algProperties,
                                algorithms.count))
                        return log_oom_debug();

                if (r == 0)
                        break;

                /* Set current_alg to alg id after last alg id the TPM provided */
                current_alg = algorithms.algProperties[algorithms.count - 1].alg + 1;
        }

        /* Cache the command capabilities. The spec isn't actually clear if commands can be added/removed
         * while running, but that would be crazy, so let's hope it is not possible. */
        TPM2_CC current_cc = TPM2_CC_FIRST;
        for (;;) {
                r = tpm2_get_capability(
                                c,
                                TPM2_CAP_COMMANDS,
                                current_cc,
                                TPM2_MAX_CAP_CC,
                                &capability);
                if (r < 0)
                        return r;

                TPML_CCA commands = capability.command;

                /* We should never get 0; the TPM must support some commands, and it must not set 'more' if
                 * there are no more. */
                assert(commands.count > 0);

                if (!GREEDY_REALLOC_APPEND(
                                c->capability_commands,
                                c->n_capability_commands,
                                commands.commandAttributes,
                                commands.count))
                        return log_oom_debug();

                if (r == 0)
                        break;

                /* Set current_cc to index after last cc the TPM provided */
                current_cc = TPMA_CC_TO_TPM2_CC(commands.commandAttributes[commands.count - 1]) + 1;
        }

        /* Cache the ECC curves. The spec isn't actually clear if ECC curves can be added/removed
         * while running, but that would be crazy, so let's hope it is not possible. */
        TPM2_ECC_CURVE current_ecc_curve = TPM2_ECC_NONE;
        for (;;) {
                r = tpm2_get_capability(
                                c,
                                TPM2_CAP_ECC_CURVES,
                                current_ecc_curve,
                                TPM2_MAX_ECC_CURVES,
                                &capability);
                if (r == -ENXIO) /* If the TPM doesn't support ECC, it might return TPM2_RC_VALUE rather than capability.eccCurves == 0 */
                        break;
                if (r < 0)
                        return r;

                TPML_ECC_CURVE ecc_curves = capability.eccCurves;

                /* ECC support isn't required */
                if (ecc_curves.count == 0)
                        break;

                if (!GREEDY_REALLOC_APPEND(
                                c->capability_ecc_curves,
                                c->n_capability_ecc_curves,
                                ecc_curves.eccCurves,
                                ecc_curves.count))
                        return log_oom_debug();

                if (r == 0)
                        break;

                /* Set current_ecc_curve to index after last ecc curve the TPM provided */
                current_ecc_curve = ecc_curves.eccCurves[ecc_curves.count - 1] + 1;
        }

        /* Cache the PCR capabilities, which are safe to cache, as the only way they can change is
         * TPM2_PCR_Allocate(), which changes the allocation after the next _TPM_Init(). If the TPM is
         * reinitialized while we are using it, all our context and sessions will be invalid, so we can
         * safely assume the TPM PCR allocation will not change while we are using it. */
        r = tpm2_get_capability(
                        c,
                        TPM2_CAP_PCRS,
                        /* property= */ 0,
                        /* count= */ 1,
                        &capability);
        if (r < 0)
                return r;
        if (r == 1)
                /* This should never happen. Part 3 ("Commands") of the TCG TPM2 spec in the section for
                 * TPM2_GetCapability states: "TPM_CAP_PCRS – Returns the current allocation of PCR in a
                 * TPML_PCR_SELECTION. The property parameter shall be zero. The TPM will always respond to
                 * this command with the full PCR allocation and moreData will be NO." */
                log_debug("TPM bug: reported multiple PCR sets; using only first set.");
        c->capability_pcrs = capability.assignedPCR;

        return 0;
}

/* Get the TPMA_ALGORITHM for a TPM2_ALG_ID. Returns true if the TPM supports the algorithm and the
 * TPMA_ALGORITHM is provided, otherwise false. */
static bool tpm2_get_capability_alg(Tpm2Context *c, TPM2_ALG_ID alg, TPMA_ALGORITHM *ret) {
        assert(c);

        FOREACH_ARRAY(alg_prop, c->capability_algorithms, c->n_capability_algorithms)
                if (alg_prop->alg == alg) {
                        if (ret)
                                *ret = alg_prop->algProperties;
                        return true;
                }

        log_debug("TPM does not support alg 0x%02" PRIx16 ".", alg);
        if (ret)
                *ret = 0;

        return false;
}

bool tpm2_supports_alg(Tpm2Context *c, TPM2_ALG_ID alg) {
        return tpm2_get_capability_alg(c, alg, NULL);
}

/* Get the TPMA_CC for a TPM2_CC. Returns true if the TPM supports the command and the TPMA_CC is provided,
 * otherwise false. */
static bool tpm2_get_capability_command(Tpm2Context *c, TPM2_CC command, TPMA_CC *ret) {
        assert(c);

        FOREACH_ARRAY(cca, c->capability_commands, c->n_capability_commands)
                if (TPMA_CC_TO_TPM2_CC(*cca) == command) {
                        if (ret)
                                *ret = *cca;
                        return true;
                }

        log_debug("TPM does not support command 0x%04" PRIx32 ".", command);
        if (ret)
                *ret = 0;

        return false;
}

bool tpm2_supports_command(Tpm2Context *c, TPM2_CC command) {
        return tpm2_get_capability_command(c, command, NULL);
}

/* Returns true if the TPM supports the ECC curve, otherwise false. */
bool tpm2_supports_ecc_curve(Tpm2Context *c, TPM2_ECC_CURVE ecc_curve) {
        assert(c);

        FOREACH_ARRAY(curve, c->capability_ecc_curves, c->n_capability_ecc_curves)
                if (*curve == ecc_curve)
                        return true;

        log_debug("TPM does not support ECC curve 0x%" PRIx16 ".", ecc_curve);
        return false;
}

/* Query the TPM for populated handles.
 *
 * This provides an array of handle indexes populated in the TPM, starting at the requested handle. The array will
 * contain only populated handle addresses (which might not include the requested handle). The number of
 * handles will be no more than the 'max' number requested. This will not search past the end of the handle
 * range (i.e. handle & 0xff000000).
 *
 * Returns 0 if all populated handles in the range (starting at the requested handle) were provided (or no
 * handles were in the range), or 1 if there are more populated handles in the range, or < 0 on any error. */
static int tpm2_get_capability_handles(
                Tpm2Context *c,
                TPM2_HANDLE start,
                size_t max,
                TPM2_HANDLE **ret_handles,
                size_t *ret_n_handles) {

        _cleanup_free_ TPM2_HANDLE *handles = NULL;
        size_t n_handles = 0;
        TPM2_HANDLE current = start;
        int r = 0;

        assert(c);
        assert(ret_handles);
        assert(ret_n_handles);

        max = MIN(max, UINT32_MAX);

        while (max > 0) {
                TPMU_CAPABILITIES capability;
                r = tpm2_get_capability(c, TPM2_CAP_HANDLES, current, (uint32_t) max, &capability);
                if (r < 0)
                        return r;

                TPML_HANDLE handle_list = capability.handles;
                if (handle_list.count == 0)
                        break;

                assert(handle_list.count <= max);

                if (n_handles > SIZE_MAX - handle_list.count)
                        return log_oom_debug();

                if (!GREEDY_REALLOC_APPEND(handles, n_handles, handle_list.handle, handle_list.count))
                        return log_oom_debug();

                max -= handle_list.count;

                /* Update current to the handle index after the last handle in the list. */
                current = handles[n_handles - 1] + 1;

                if (r == 0)
                        /* No more handles in this range. */
                        break;
        }

        *ret_handles = TAKE_PTR(handles);
        *ret_n_handles = n_handles;

        return r;
}

#define TPM2_HANDLE_RANGE(h) ((TPM2_HANDLE)((h) & TPM2_HR_RANGE_MASK))
#define TPM2_HANDLE_TYPE(h) ((TPM2_HT)(TPM2_HANDLE_RANGE(h) >> TPM2_HR_SHIFT))

/* Returns 1 if the handle is populated in the TPM, 0 if not, and < 0 on any error. */
static int tpm2_get_capability_handle(Tpm2Context *c, TPM2_HANDLE handle) {
        _cleanup_free_ TPM2_HANDLE *handles = NULL;
        size_t n_handles = 0;
        int r;

        r = tpm2_get_capability_handles(c, handle, 1, &handles, &n_handles);
        if (r < 0)
                return r;

        return n_handles == 0 ? false : handles[0] == handle;
}

/* Returns 1 if the TPM supports the parms, or 0 if the TPM does not support the parms. */
bool tpm2_test_parms(Tpm2Context *c, TPMI_ALG_PUBLIC alg, const TPMU_PUBLIC_PARMS *parms) {
        TSS2_RC rc;

        assert(c);
        assert(parms);

        TPMT_PUBLIC_PARMS parameters = {
                .type = alg,
                .parameters = *parms,
        };

        rc = sym_Esys_TestParms(c->esys_context, ESYS_TR_NONE, ESYS_TR_NONE, ESYS_TR_NONE, &parameters);
        if (rc != TSS2_RC_SUCCESS)
                /* The spec says if the parms are not supported the TPM returns "...the appropriate
                 * unmarshaling error if a parameter is not valid". Since the spec (currently) defines 15
                 * unmarshaling errors, instead of checking for them all here, let's just assume any error
                 * indicates unsupported parms, and log the specific error text. */
                log_debug("TPM does not support tested parms: %s", sym_Tss2_RC_Decode(rc));

        return rc == TSS2_RC_SUCCESS;
}

static bool tpm2_supports_tpmt_public(Tpm2Context *c, const TPMT_PUBLIC *public) {
        assert(c);
        assert(public);

        return tpm2_test_parms(c, public->type, &public->parameters);
}

static bool tpm2_supports_tpmt_sym_def_object(Tpm2Context *c, const TPMT_SYM_DEF_OBJECT *parameters) {
        assert(c);
        assert(parameters);

        TPMU_PUBLIC_PARMS parms = {
                .symDetail.sym = *parameters,
        };

        return tpm2_test_parms(c, TPM2_ALG_SYMCIPHER, &parms);
}

static bool tpm2_supports_tpmt_sym_def(Tpm2Context *c, const TPMT_SYM_DEF *parameters) {
        assert(c);
        assert(parameters);

        /* Unfortunately, TPMT_SYM_DEF and TPMT_SYM_DEF_OBEJECT are separately defined, even though they are
         * functionally identical. */
        TPMT_SYM_DEF_OBJECT object = {
                .algorithm = parameters->algorithm,
                .keyBits = parameters->keyBits,
                .mode = parameters->mode,
        };

        return tpm2_supports_tpmt_sym_def_object(c, &object);
}

static Tpm2Context *tpm2_context_free(Tpm2Context *c) {
        if (!c)
                return NULL;

        if (c->esys_context)
                sym_Esys_Finalize(&c->esys_context);

        c->tcti_context = mfree(c->tcti_context);
        c->tcti_dl = safe_dlclose(c->tcti_dl);

        c->capability_algorithms = mfree(c->capability_algorithms);
        c->capability_commands = mfree(c->capability_commands);
        c->capability_ecc_curves = mfree(c->capability_ecc_curves);

        return mfree(c);
}

DEFINE_TRIVIAL_REF_UNREF_FUNC(Tpm2Context, tpm2_context, tpm2_context_free);

static const TPMT_SYM_DEF SESSION_TEMPLATE_SYM_AES_128_CFB = {
        .algorithm = TPM2_ALG_AES,
        .keyBits.aes = 128,
        .mode.aes = TPM2_ALG_CFB, /* The spec requires sessions to use CFB. */
};

int tpm2_context_new(const char *device, Tpm2Context **ret_context) {
        _cleanup_(tpm2_context_unrefp) Tpm2Context *context = NULL;
        TSS2_RC rc;
        int r;

        assert(ret_context);

        context = new(Tpm2Context, 1);
        if (!context)
                return log_oom_debug();

        *context = (Tpm2Context) {
                .n_ref = 1,
        };

        r = dlopen_tpm2();
        if (r < 0)
                return log_debug_errno(r, "TPM2 support not installed: %m");

        if (!device) {
                device = secure_getenv("SYSTEMD_TPM2_DEVICE");
                if (device)
                        /* Setting the env var to an empty string forces tpm2-tss' own device picking
                         * logic to be used. */
                        device = empty_to_null(device);
                else
                        /* If nothing was specified explicitly, we'll use a hardcoded default: the "device" tcti
                         * driver and the "/dev/tpmrm0" device. We do this since on some distributions the tpm2-abrmd
                         * might be used and we really don't want that, since it is a system service and that creates
                         * various ordering issues/deadlocks during early boot. */
                        device = "device:/dev/tpmrm0";
        }

        if (device) {
                const char *param, *driver, *fn;
                const TSS2_TCTI_INFO* info;
                TSS2_TCTI_INFO_FUNC func;
                size_t sz = 0;

                param = strchr(device, ':');
                if (param) {
                        /* Syntax #1: Pair of driver string and arbitrary parameter */
                        driver = strndupa_safe(device, param - device);
                        if (isempty(driver))
                                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "TPM2 driver name is empty, refusing.");

                        param++;
                } else if (path_is_absolute(device) && path_is_valid(device)) {
                        /* Syntax #2: TPM device node */
                        driver = "device";
                        param = device;
                } else
                        return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Invalid TPM2 driver string, refusing.");

                log_debug("Using TPM2 TCTI driver '%s' with device '%s'.", driver, param);

                fn = strjoina("libtss2-tcti-", driver, ".so.0");

                /* Better safe than sorry, let's refuse strings that cannot possibly be valid driver early, before going to disk. */
                if (!filename_is_valid(fn))
                        return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "TPM2 driver name '%s' not valid, refusing.", driver);

                context->tcti_dl = dlopen(fn, RTLD_NOW);
                if (!context->tcti_dl)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOPKG), "Failed to load %s: %s", fn, dlerror());

                log_debug("Loaded '%s' via dlopen()", fn);

                func = dlsym(context->tcti_dl, TSS2_TCTI_INFO_SYMBOL);
                if (!func)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                               "Failed to find TCTI info symbol " TSS2_TCTI_INFO_SYMBOL ": %s",
                                               dlerror());

                info = func();
                if (!info)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Unable to get TCTI info data.");

                log_debug("Loaded TCTI module '%s' (%s) [Version %" PRIu32 "]", info->name, info->description, info->version);

                rc = info->init(/* context= */ NULL, &sz, /* param= */ NULL);
                if (rc != TPM2_RC_SUCCESS)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                               "Failed to initialize TCTI context: %s", sym_Tss2_RC_Decode(rc));

                context->tcti_context = malloc0(sz);
                if (!context->tcti_context)
                        return log_oom_debug();

                rc = info->init(context->tcti_context, &sz, param);
                if (rc != TPM2_RC_SUCCESS)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                               "Failed to initialize TCTI context: %s", sym_Tss2_RC_Decode(rc));
        }

        rc = sym_Esys_Initialize(&context->esys_context, context->tcti_context, NULL);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to initialize TPM context: %s", sym_Tss2_RC_Decode(rc));

        rc = sym_Esys_Startup(context->esys_context, TPM2_SU_CLEAR);
        if (rc == TPM2_RC_INITIALIZE)
                log_debug("TPM already started up.");
        else if (rc == TSS2_RC_SUCCESS)
                log_debug("TPM successfully started up.");
        else
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to start up TPM: %s", sym_Tss2_RC_Decode(rc));

        r = tpm2_cache_capabilities(context);
        if (r < 0)
                return log_debug_errno(r, "Failed to cache TPM capabilities: %m");

        /* We require AES and CFB support for session encryption. */
        if (!tpm2_supports_alg(context, TPM2_ALG_AES))
                return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "TPM does not support AES.");

        if (!tpm2_supports_alg(context, TPM2_ALG_CFB))
                return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "TPM does not support CFB.");

        if (!tpm2_supports_tpmt_sym_def(context, &SESSION_TEMPLATE_SYM_AES_128_CFB))
                return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "TPM does not support AES-128-CFB.");

        *ret_context = TAKE_PTR(context);

        return 0;
}

int tpm2_context_new_or_warn(const char *device, Tpm2Context **ret_context) {
        int r;

        assert(ret_context);

        r = tpm2_context_new(device, ret_context);
        if (r == -EOPNOTSUPP)
                return log_error_errno(r, "TPM device not usable as it does not support the required functionality (AES-128-CFB missing?).");
        if (r == -ENOPKG)
                return log_error_errno(r, "TPM TCTI driver not available.");
        if (r == -ENOENT)
                return log_error_errno(r, "TPM device not found.");
        if (r < 0)
                return log_error_errno(r, "Failed to create TPM2 context: %m");

        return 0;
}

static void tpm2_handle_cleanup(ESYS_CONTEXT *esys_context, ESYS_TR esys_handle, bool flush) {
        TSS2_RC rc;

        if (!esys_context || esys_handle == ESYS_TR_NONE)
                return;

        /* Closing the handle removes its reference from the esys_context, but leaves the corresponding
         * handle in the actual TPM. Flushing the handle removes its reference from the esys_context as well
         * as removing its corresponding handle from the actual TPM. */
        if (flush)
                rc = sym_Esys_FlushContext(esys_context, esys_handle);
        else
                /* We can't use Esys_TR_Close() because the tpm2-tss library does not use reference counting
                 * for handles, and a single Esys_TR_Close() will remove the handle (internal to the tpm2-tss
                 * library) that might be in use by other code that is using the same ESYS_CONTEXT. This
                 * directly affects us; for example the src/test/test-tpm2.c test function
                 * check_seal_unseal() will encounter this issue and will result in a failure when trying to
                 * cleanup (i.e. Esys_FlushContext) the transient primary key that the test function
                 * generates. However, not calling Esys_TR_Close() here should be ok, since any leaked handle
                 * references will be cleaned up when we free our ESYS_CONTEXT.
                 *
                 * An upstream bug is open here: https://github.com/tpm2-software/tpm2-tss/issues/2693 */
                rc = TSS2_RC_SUCCESS; // FIXME: restore sym_Esys_TR_Close() use once tpm2-tss is fixed and adopted widely enough
        if (rc != TSS2_RC_SUCCESS)
                /* We ignore failures here (besides debug logging), since this is called in error paths,
                 * where we cannot do anything about failures anymore. And when it is called in successful
                 * codepaths by this time we already did what we wanted to do, and got the results we wanted
                 * so there's no reason to make this fail more loudly than necessary. */
                log_debug("Failed to %s TPM handle, ignoring: %s", flush ? "flush" : "close", sym_Tss2_RC_Decode(rc));
}

Tpm2Handle *tpm2_handle_free(Tpm2Handle *handle) {
        if (!handle)
                return NULL;

        _cleanup_(tpm2_context_unrefp) Tpm2Context *context = (Tpm2Context*)handle->tpm2_context;
        if (context)
                tpm2_handle_cleanup(context->esys_context, handle->esys_handle, handle->flush);

        return mfree(handle);
}

int tpm2_handle_new(Tpm2Context *context, Tpm2Handle **ret_handle) {
        _cleanup_(tpm2_handle_freep) Tpm2Handle *handle = NULL;

        assert(ret_handle);

        handle = new(Tpm2Handle, 1);
        if (!handle)
                return log_oom_debug();

        *handle = (Tpm2Handle) {
                .tpm2_context = tpm2_context_ref(context),
                .esys_handle = ESYS_TR_NONE,
                .flush = true,
        };

        *ret_handle = TAKE_PTR(handle);

        return 0;
}

static int tpm2_read_public(
                Tpm2Context *c,
                const Tpm2Handle *session,
                const Tpm2Handle *handle,
                TPM2B_PUBLIC **ret_public,
                TPM2B_NAME **ret_name,
                TPM2B_NAME **ret_qname) {

        TSS2_RC rc;

        assert(c);
        assert(handle);

        rc = sym_Esys_ReadPublic(
                        c->esys_context,
                        handle->esys_handle,
                        session ? session->esys_handle : ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        ret_public,
                        ret_name,
                        ret_qname);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to read public info: %s", sym_Tss2_RC_Decode(rc));

        return 0;
}

/* Create a Tpm2Handle object that references a pre-existing handle in the TPM, at the handle index provided.
 * This should be used only for persistent, transient, or NV handles; and the handle must already exist in
 * the TPM at the specified handle index. The handle index should not be 0. Returns 1 if found, 0 if the
 * index is empty, or < 0 on error. Also see tpm2_get_srk() below; the SRK is a commonly used persistent
 * Tpm2Handle. */
int tpm2_index_to_handle(
                Tpm2Context *c,
                TPM2_HANDLE index,
                const Tpm2Handle *session,
                TPM2B_PUBLIC **ret_public,
                TPM2B_NAME **ret_name,
                TPM2B_NAME **ret_qname,
                Tpm2Handle **ret_handle) {

        TSS2_RC rc;
        int r;

        assert(c);

        /* Only allow persistent, transient, or NV index handle types. */
        switch (TPM2_HANDLE_TYPE(index)) {
        case TPM2_HT_PERSISTENT:
        case TPM2_HT_NV_INDEX:
        case TPM2_HT_TRANSIENT:
                break;
        case TPM2_HT_PCR:
                /* PCR handles are referenced by their actual index number and do not need a Tpm2Handle */
                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "Invalid handle 0x%08" PRIx32 " (in PCR range).", index);
        case TPM2_HT_HMAC_SESSION:
        case TPM2_HT_POLICY_SESSION:
                /* Session indexes are only used internally by tpm2-tss (or lower code) */
                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "Invalid handle 0x%08" PRIx32 " (in session range).", index);
        case TPM2_HT_PERMANENT:
                /* Permanent handles are defined, e.g. ESYS_TR_RH_OWNER. */
                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "Invalid handle 0x%08" PRIx32 " (in permanent range).", index);
        default:
                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "Invalid handle 0x%08" PRIx32 " (in unknown range).", index);
        }

        /* For transient handles, the kernel tpm "resource manager" (i.e. /dev/tpmrm0) performs mapping
         * which breaks GetCapability requests, so only check GetCapability if it's not a transient handle.
         * https://bugzilla.kernel.org/show_bug.cgi?id=218009 */
        if (TPM2_HANDLE_TYPE(index) != TPM2_HT_TRANSIENT) { // FIXME: once kernel bug is fixed, check transient handles too
                r = tpm2_get_capability_handle(c, index);
                if (r < 0)
                        return r;
                if (r == 0) {
                        log_debug("TPM handle 0x%08" PRIx32 " not populated.", index);
                        if (ret_public)
                                *ret_public = NULL;
                        if (ret_name)
                                *ret_name = NULL;
                        if (ret_qname)
                                *ret_qname = NULL;
                        if (ret_handle)
                                *ret_handle = NULL;
                        return 0;
                }
        }

        _cleanup_(tpm2_handle_freep) Tpm2Handle *handle = NULL;
        r = tpm2_handle_new(c, &handle);
        if (r < 0)
                return r;

        /* Since we didn't create this handle in the TPM (this is only creating an ESYS_TR handle for the
         * pre-existing TPM handle), we shouldn't flush (or evict) it on cleanup. */
        handle->flush = false;

        rc = sym_Esys_TR_FromTPMPublic(
                        c->esys_context,
                        index,
                        session ? session->esys_handle : ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        &handle->esys_handle);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to read public info: %s", sym_Tss2_RC_Decode(rc));

        if (ret_public || ret_name || ret_qname) {
                r = tpm2_read_public(c, session, handle, ret_public, ret_name, ret_qname);
                if (r < 0)
                        return r;
        }

        if (ret_handle)
                *ret_handle = TAKE_PTR(handle);

        return 1;
}

/* Get the handle index for the provided Tpm2Handle. */
int tpm2_index_from_handle(Tpm2Context *c, const Tpm2Handle *handle, TPM2_HANDLE *ret_index) {
        TSS2_RC rc;

        assert(c);
        assert(handle);
        assert(ret_index);

        /* Esys_TR_GetTpmHandle was added to tpm2-tss in version 2.4.0. Once we can set a minimum tpm2-tss
         * version of 2.4.0 this check can be removed. */
        if (!sym_Esys_TR_GetTpmHandle)
                return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
                                       "libtss2-esys too old, does not include Esys_TR_GetTpmHandle.");

        rc = sym_Esys_TR_GetTpmHandle(c->esys_context, handle->esys_handle, ret_index);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to get handle index: %s", sym_Tss2_RC_Decode(rc));

        return 0;
}

/* Copy an object in the TPM at a transient handle to a persistent handle.
 *
 * The provided transient handle must exist in the TPM in the transient range. The persistent handle may be 0
 * or any handle in the persistent range. If 0, this will try each handle in the persistent range, in
 * ascending order, until an available one is found. If non-zero, only the requested persistent handle will
 * be used.
 *
 * Note that the persistent handle parameter is an handle index (i.e. number), while the transient handle is
 * a Tpm2Handle object. The returned persistent handle will be a Tpm2Handle object that is located in the TPM
 * at the requested persistent handle index (or the first available if none was requested).
 *
 * Returns 1 if the object was successfully persisted, or 0 if there is already a key at the requested
 * handle, or < 0 on error. Theoretically, this would also return 0 if no specific persistent handle is
 * requested but all persistent handles are used, but it is extremely unlikely the TPM has enough internal
 * memory to store the entire persistent range, in which case an error will be returned if the TPM is out of
 * memory for persistent storage. The persistent handle is only provided when returning 1. */
static int tpm2_persist_handle(
                Tpm2Context *c,
                const Tpm2Handle *transient_handle,
                const Tpm2Handle *session,
                TPMI_DH_PERSISTENT persistent_handle_index,
                Tpm2Handle **ret_persistent_handle) {

        /* We don't use TPM2_PERSISTENT_FIRST and TPM2_PERSISTENT_LAST here due to:
         * https://github.com/systemd/systemd/pull/27713#issuecomment-1591864753 */
        TPMI_DH_PERSISTENT first = UINT32_C(0x81000000), last = UINT32_C(0x81ffffff);
        TSS2_RC rc;
        int r;

        assert(c);
        assert(transient_handle);

        /* If persistent handle index specified, only try that. */
        if (persistent_handle_index != 0) {
                if (TPM2_HANDLE_TYPE(persistent_handle_index) != TPM2_HT_PERSISTENT)
                        return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
                                               "Handle not in persistent range: 0x%x", persistent_handle_index);

                first = last = persistent_handle_index;
        }

        for (TPMI_DH_PERSISTENT requested = first; requested <= last; requested++) {
                _cleanup_(tpm2_handle_freep) Tpm2Handle *persistent_handle = NULL;
                r = tpm2_handle_new(c, &persistent_handle);
                if (r < 0)
                        return r;

                /* Since this is a persistent handle, don't flush it. */
                persistent_handle->flush = false;

                rc = sym_Esys_EvictControl(
                                c->esys_context,
                                ESYS_TR_RH_OWNER,
                                transient_handle->esys_handle,
                                session ? session->esys_handle : ESYS_TR_PASSWORD,
                                ESYS_TR_NONE,
                                ESYS_TR_NONE,
                                requested,
                                &persistent_handle->esys_handle);
                if (rc == TSS2_RC_SUCCESS) {
                        if (ret_persistent_handle)
                                *ret_persistent_handle = TAKE_PTR(persistent_handle);

                        return 1;
                }
                if (rc != TPM2_RC_NV_DEFINED)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                               "Failed to persist handle: %s", sym_Tss2_RC_Decode(rc));
        }

        if (ret_persistent_handle)
                *ret_persistent_handle = NULL;

        return 0;
}

#define TPM2_CREDIT_RANDOM_FLAG_PATH "/run/systemd/tpm-rng-credited"

static int tpm2_credit_random(Tpm2Context *c) {
        size_t rps, done = 0;
        TSS2_RC rc;
        usec_t t;
        int r;

        assert(c);

        /* Pulls some entropy from the TPM and adds it into the kernel RNG pool. That way we can say that the
         * key we will ultimately generate with the kernel random pool is at least as good as the TPM's RNG,
         * but likely better. Note that we don't trust the TPM RNG very much, hence do not actually credit
         * any entropy. */

        if (access(TPM2_CREDIT_RANDOM_FLAG_PATH, F_OK) < 0) {
                if (errno != ENOENT)
                        log_debug_errno(errno, "Failed to detect if '" TPM2_CREDIT_RANDOM_FLAG_PATH "' exists, ignoring: %m");
        } else {
                log_debug("Not adding TPM2 entropy to the kernel random pool again.");
                return 0; /* Already done */
        }

        t = now(CLOCK_MONOTONIC);

        for (rps = random_pool_size(); rps > 0;) {
                _cleanup_(Esys_Freep) TPM2B_DIGEST *buffer = NULL;

                rc = sym_Esys_GetRandom(
                                c->esys_context,
                                ESYS_TR_NONE,
                                ESYS_TR_NONE,
                                ESYS_TR_NONE,
                                MIN(rps, 32U), /* 32 is supposedly a safe choice, given that AES 256bit keys are this long, and TPM2 baseline requires support for those. */
                                &buffer);
                if (rc != TSS2_RC_SUCCESS)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                               "Failed to acquire entropy from TPM: %s", sym_Tss2_RC_Decode(rc));

                if (buffer->size == 0)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                               "Zero-sized entropy returned from TPM.");

                r = random_write_entropy(-1, buffer->buffer, buffer->size, /* credit= */ false);
                if (r < 0)
                        return log_debug_errno(r, "Failed wo write entropy to kernel: %m");

                done += buffer->size;
                rps = LESS_BY(rps, buffer->size);
        }

        log_debug("Added %zu bytes of TPM2 entropy to the kernel random pool in %s.", done, FORMAT_TIMESPAN(now(CLOCK_MONOTONIC) - t, 0));

        r = touch(TPM2_CREDIT_RANDOM_FLAG_PATH);
        if (r < 0)
                log_debug_errno(r, "Failed to touch '" TPM2_CREDIT_RANDOM_FLAG_PATH "', ignoring: %m");

        return 0;
}

/* Get one of the legacy primary key templates.
 *
 * The legacy templates should only be used for older sealed data that did not use the SRK. Instead of a
 * persistent SRK, a transient key was created to seal the data and then flushed; and the exact same template
 * must be used to recreate the same transient key to unseal the data. The alg parameter must be TPM2_ALG_RSA
 * or TPM2_ALG_ECC. This does not check if the alg is actually supported on this TPM. */
static int tpm2_get_legacy_template(TPMI_ALG_PUBLIC alg, TPMT_PUBLIC *ret_template) {
        /* Do not modify. */
        static const TPMT_PUBLIC legacy_ecc = {
                .type = TPM2_ALG_ECC,
                .nameAlg = TPM2_ALG_SHA256,
                .objectAttributes =
                        TPMA_OBJECT_RESTRICTED|
                        TPMA_OBJECT_DECRYPT|
                        TPMA_OBJECT_FIXEDTPM|
                        TPMA_OBJECT_FIXEDPARENT|
                        TPMA_OBJECT_SENSITIVEDATAORIGIN|
                        TPMA_OBJECT_USERWITHAUTH,
                .parameters.eccDetail = {
                        .symmetric = {
                                .algorithm = TPM2_ALG_AES,
                                .keyBits.aes = 128,
                                .mode.aes = TPM2_ALG_CFB,
                        },
                        .scheme.scheme = TPM2_ALG_NULL,
                        .curveID = TPM2_ECC_NIST_P256,
                        .kdf.scheme = TPM2_ALG_NULL,
                },
        };

        /* Do not modify. */
        static const TPMT_PUBLIC legacy_rsa = {
                .type = TPM2_ALG_RSA,
                .nameAlg = TPM2_ALG_SHA256,
                .objectAttributes = TPMA_OBJECT_RESTRICTED|TPMA_OBJECT_DECRYPT|TPMA_OBJECT_FIXEDTPM|TPMA_OBJECT_FIXEDPARENT|TPMA_OBJECT_SENSITIVEDATAORIGIN|TPMA_OBJECT_USERWITHAUTH,
                .parameters.rsaDetail = {
                        .symmetric = {
                                .algorithm = TPM2_ALG_AES,
                                .keyBits.aes = 128,
                                .mode.aes = TPM2_ALG_CFB,
                        },
                        .scheme.scheme = TPM2_ALG_NULL,
                        .keyBits = 2048,
                },
        };

        assert(ret_template);

        if (alg == TPM2_ALG_ECC)
                *ret_template = legacy_ecc;
        else if (alg == TPM2_ALG_RSA)
                *ret_template = legacy_rsa;
        else
                return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
                                       "Unsupported legacy SRK alg: 0x%x", alg);

        return 0;
}

/* Get a Storage Root Key (SRK) template.
 *
 * The SRK template values are recommended by the "TCG TPM v2.0 Provisioning Guidance" document in section
 * 7.5.1 "Storage Primary Key (SRK) Templates", referencing "TCG EK Credential Profile for TPM Family 2.0".
 * The EK Credential Profile version 2.0 provides only a single template each for RSA and ECC, while later EK
 * Credential Profile versions provide more templates, and keep the original templates as "L-1" (for RSA) and
 * "L-2" (for ECC).
 *
 * https://trustedcomputinggroup.org/resource/tcg-tpm-v2-0-provisioning-guidance
 * https://trustedcomputinggroup.org/resource/http-trustedcomputinggroup-org-wp-content-uploads-tcg-ek-credential-profile
 *
 * These templates are only needed to create a new persistent SRK (or a new transient key that is
 * SRK-compatible). Preferably, the TPM should contain a shared SRK located at the reserved shared SRK handle
 * (see TPM2_SRK_HANDLE in tpm2-util.h, and tpm2_get_srk() below).
 *
 * Returns 0 if the specified algorithm is ECC or RSA, otherwise -EOPNOTSUPP. */
int tpm2_get_srk_template(TPMI_ALG_PUBLIC alg, TPMT_PUBLIC *ret_template) {
        /* The attributes are the same between ECC and RSA templates. This has the changes specified in the
         * Provisioning Guidance document, specifically:
         * TPMA_OBJECT_USERWITHAUTH is added.
         * TPMA_OBJECT_ADMINWITHPOLICY is removed.
         * TPMA_OBJECT_NODA is added. */
        TPMA_OBJECT srk_attributes =
                        TPMA_OBJECT_DECRYPT |
                        TPMA_OBJECT_FIXEDPARENT |
                        TPMA_OBJECT_FIXEDTPM |
                        TPMA_OBJECT_NODA |
                        TPMA_OBJECT_RESTRICTED |
                        TPMA_OBJECT_SENSITIVEDATAORIGIN |
                        TPMA_OBJECT_USERWITHAUTH;

        /* The symmetric configuration is the same between ECC and RSA templates. */
        TPMT_SYM_DEF_OBJECT srk_symmetric = {
                .algorithm = TPM2_ALG_AES,
                .keyBits.aes = 128,
                .mode.aes = TPM2_ALG_CFB,
        };

        /* Both templates have an empty authPolicy as specified by the Provisioning Guidance document. */

        /* From the EK Credential Profile template "L-2". */
        TPMT_PUBLIC srk_ecc = {
                .type = TPM2_ALG_ECC,
                .nameAlg = TPM2_ALG_SHA256,
                .objectAttributes = srk_attributes,
                .parameters.eccDetail = {
                        .symmetric = srk_symmetric,
                        .scheme.scheme = TPM2_ALG_NULL,
                        .curveID = TPM2_ECC_NIST_P256,
                        .kdf.scheme = TPM2_ALG_NULL,
                },
        };

        /* From the EK Credential Profile template "L-1". */
        TPMT_PUBLIC srk_rsa = {
                .type = TPM2_ALG_RSA,
                .nameAlg = TPM2_ALG_SHA256,
                .objectAttributes = srk_attributes,
                .parameters.rsaDetail = {
                        .symmetric = srk_symmetric,
                        .scheme.scheme = TPM2_ALG_NULL,
                        .keyBits = 2048,
                },
        };

        assert(ret_template);

        switch (alg) {
        case TPM2_ALG_ECC:
                *ret_template = srk_ecc;
                return 0;
        case TPM2_ALG_RSA:
                *ret_template = srk_rsa;
                return 0;
        }

        return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "No SRK for algorithm 0x%" PRIx16, alg);
}

/* Get the best supported SRK template. ECC is preferred, then RSA. */
int tpm2_get_best_srk_template(Tpm2Context *c, TPMT_PUBLIC *ret_template) {
        TPMT_PUBLIC template;
        int r;

        assert(c);
        assert(ret_template);

        r = tpm2_get_srk_template(TPM2_ALG_ECC, &template);
        if (r < 0)
                return r;

        if (!tpm2_supports_alg(c, TPM2_ALG_ECC))
                log_debug("TPM does not support ECC.");
        else if (!tpm2_supports_ecc_curve(c, template.parameters.eccDetail.curveID))
                log_debug("TPM does not support ECC-NIST-P256 curve.");
        else if (!tpm2_supports_tpmt_public(c, &template))
                log_debug("TPM does not support SRK ECC template L-2.");
        else {
                *ret_template = template;
                return 0;
        }

        r = tpm2_get_srk_template(TPM2_ALG_RSA, &template);
        if (r < 0)
                return r;

        if (!tpm2_supports_alg(c, TPM2_ALG_RSA))
                log_debug("TPM does not support RSA.");
        else if (!tpm2_supports_tpmt_public(c, &template))
                log_debug("TPM does not support SRK RSA template L-1.");
        else {
                *ret_template = template;
                return 0;
        }

        return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
                               "TPM does not support either SRK template L-1 (RSA) or L-2 (ECC).");
}

/* Get the SRK. Returns 1 if SRK is found, 0 if there is no SRK, or < 0 on error. Also see
 * tpm2_get_or_create_srk() below. */
int tpm2_get_srk(
                Tpm2Context *c,
                const Tpm2Handle *session,
                TPM2B_PUBLIC **ret_public,
                TPM2B_NAME **ret_name,
                TPM2B_NAME **ret_qname,
                Tpm2Handle **ret_handle) {

        return tpm2_index_to_handle(c, TPM2_SRK_HANDLE, session, ret_public, ret_name, ret_qname, ret_handle);
}

/* Get the SRK, creating one if needed. Returns 1 if a new SRK was created and persisted, 0 if an SRK already
 * exists, or < 0 on error. */
int tpm2_get_or_create_srk(
                Tpm2Context *c,
                const Tpm2Handle *session,
                TPM2B_PUBLIC **ret_public,
                TPM2B_NAME **ret_name,
                TPM2B_NAME **ret_qname,
                Tpm2Handle **ret_handle) {

        int r;

        r = tpm2_get_srk(c, session, ret_public, ret_name, ret_qname, ret_handle);
        if (r < 0)
                return r;
        if (r == 1)
                return 0; /* 0 → SRK already set up */

        /* No SRK, create and persist one */
        TPM2B_PUBLIC template = {
                .size = sizeof(TPMT_PUBLIC),
        };
        r = tpm2_get_best_srk_template(c, &template.publicArea);
        if (r < 0)
                return log_debug_errno(r, "Could not get best SRK template: %m");

        _cleanup_(tpm2_handle_freep) Tpm2Handle *transient_handle = NULL;
        r = tpm2_create_primary(
                        c,
                        session,
                        &template,
                        /* sensitive= */ NULL,
                        /* ret_public= */ NULL,
                        &transient_handle);
        if (r < 0)
                return r;

        /* Try to persist the transient SRK we created. No locking needed; if multiple threads are trying to
         * persist SRKs concurrently, only one will succeed (r == 1) while the rest will fail (r == 0). In
         * either case, all threads will get the persistent SRK below. */
        r = tpm2_persist_handle(c, transient_handle, session, TPM2_SRK_HANDLE, /* ret_persistent_handle= */ NULL);
        if (r < 0)
                return r;

        /* The SRK should exist now. */
        r = tpm2_get_srk(c, session, ret_public, ret_name, ret_qname, ret_handle);
        if (r < 0)
                return r;
        if (r == 0)
                /* This should never happen. */
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "SRK we just persisted couldn't be found.");

        return 1; /* > 0 → SRK newly set up */
}

/* Utility functions for TPMS_PCR_SELECTION. */

/* Convert a TPMS_PCR_SELECTION object to a mask. */
uint32_t tpm2_tpms_pcr_selection_to_mask(const TPMS_PCR_SELECTION *s) {
        assert(s);
        assert(s->sizeofSelect <= sizeof(s->pcrSelect));

        uint32_t mask = 0;
        for (unsigned i = 0; i < s->sizeofSelect; i++)
                SET_FLAG(mask, (uint32_t)s->pcrSelect[i] << (i * 8), true);
        return mask;
}

/* Convert a mask and hash alg to a TPMS_PCR_SELECTION object. */
void tpm2_tpms_pcr_selection_from_mask(uint32_t mask, TPMI_ALG_HASH hash_alg, TPMS_PCR_SELECTION *ret) {
        assert(ret);

        /* This is currently hardcoded at 24 PCRs, above. */
        if (!TPM2_PCR_MASK_VALID(mask))
                log_debug("PCR mask selections (%x) out of range, ignoring.",
                          mask & ~((uint32_t)TPM2_PCRS_MASK));

        *ret = (TPMS_PCR_SELECTION){
                .hash = hash_alg,
                .sizeofSelect = TPM2_PCRS_MAX / 8,
                .pcrSelect[0] = mask & 0xff,
                .pcrSelect[1] = (mask >> 8) & 0xff,
                .pcrSelect[2] = (mask >> 16) & 0xff,
        };
}

/* Test if all bits in the mask are set in the TPMS_PCR_SELECTION. */
bool tpm2_tpms_pcr_selection_has_mask(const TPMS_PCR_SELECTION *s, uint32_t mask) {
        assert(s);

        return FLAGS_SET(tpm2_tpms_pcr_selection_to_mask(s), mask);
}

static void tpm2_tpms_pcr_selection_update_mask(TPMS_PCR_SELECTION *s, uint32_t mask, bool b) {
        assert(s);

        tpm2_tpms_pcr_selection_from_mask(UPDATE_FLAG(tpm2_tpms_pcr_selection_to_mask(s), mask, b), s->hash, s);
}

/* Add all PCR selections in the mask. */
void tpm2_tpms_pcr_selection_add_mask(TPMS_PCR_SELECTION *s, uint32_t mask) {
        tpm2_tpms_pcr_selection_update_mask(s, mask, 1);
}

/* Remove all PCR selections in the mask. */
void tpm2_tpms_pcr_selection_sub_mask(TPMS_PCR_SELECTION *s, uint32_t mask) {
        tpm2_tpms_pcr_selection_update_mask(s, mask, 0);
}

/* Add all PCR selections in 'b' to 'a'. Both must have the same hash alg. */
void tpm2_tpms_pcr_selection_add(TPMS_PCR_SELECTION *a, const TPMS_PCR_SELECTION *b) {
        assert(a);
        assert(b);
        assert(a->hash == b->hash);

        tpm2_tpms_pcr_selection_add_mask(a, tpm2_tpms_pcr_selection_to_mask(b));
}

/* Remove all PCR selections in 'b' from 'a'. Both must have the same hash alg. */
void tpm2_tpms_pcr_selection_sub(TPMS_PCR_SELECTION *a, const TPMS_PCR_SELECTION *b) {
        assert(a);
        assert(b);
        assert(a->hash == b->hash);

        tpm2_tpms_pcr_selection_sub_mask(a, tpm2_tpms_pcr_selection_to_mask(b));
}

/* Move all PCR selections in 'b' to 'a'. Both must have the same hash alg. */
void tpm2_tpms_pcr_selection_move(TPMS_PCR_SELECTION *a, TPMS_PCR_SELECTION *b) {
        if (a == b)
                return;

        tpm2_tpms_pcr_selection_add(a, b);
        tpm2_tpms_pcr_selection_from_mask(0, b->hash, b);
}

#define FOREACH_TPMS_PCR_SELECTION_IN_TPML_PCR_SELECTION(tpms, tpml)    \
        _FOREACH_TPMS_PCR_SELECTION_IN_TPML_PCR_SELECTION(tpms, tpml, UNIQ_T(l, UNIQ))
#define _FOREACH_TPMS_PCR_SELECTION_IN_TPML_PCR_SELECTION(tpms, tpml, l) \
        for (typeof(tpml) (l) = (tpml); (l); (l) = NULL)                \
                FOREACH_ARRAY(tpms, (l)->pcrSelections, (l)->count)

#define FOREACH_PCR_IN_TPMS_PCR_SELECTION(pcr, tpms)                    \
        FOREACH_PCR_IN_MASK(pcr, tpm2_tpms_pcr_selection_to_mask(tpms))

#define FOREACH_PCR_IN_TPML_PCR_SELECTION(pcr, tpms, tpml)              \
        FOREACH_TPMS_PCR_SELECTION_IN_TPML_PCR_SELECTION(tpms, tpml)    \
                FOREACH_PCR_IN_TPMS_PCR_SELECTION(pcr, tpms)

char *tpm2_tpms_pcr_selection_to_string(const TPMS_PCR_SELECTION *s) {
        assert(s);

        const char *algstr = strna(tpm2_hash_alg_to_string(s->hash));

        _cleanup_free_ char *mask = tpm2_pcr_mask_to_string(tpm2_tpms_pcr_selection_to_mask(s));
        if (!mask)
                return NULL;

        return strjoin(algstr, "(", mask, ")");
}

size_t tpm2_tpms_pcr_selection_weight(const TPMS_PCR_SELECTION *s) {
        assert(s);

        return popcount(tpm2_tpms_pcr_selection_to_mask(s));
}

/* Utility functions for TPML_PCR_SELECTION. */

/* Remove the (0-based) index entry from 'l', shift all following entries, and update the count. */
static void tpm2_tpml_pcr_selection_remove_index(TPML_PCR_SELECTION *l, uint32_t index) {
        assert(l);
        assert(l->count <= ELEMENTSOF(l->pcrSelections));
        assert(index < l->count);

        size_t s = l->count - (index + 1);
        memmove(&l->pcrSelections[index], &l->pcrSelections[index + 1], s * sizeof(l->pcrSelections[0]));
        l->count--;
}

/* Get a TPMS_PCR_SELECTION from a TPML_PCR_SELECTION for the given hash alg. Returns NULL if there is no
 * entry for the hash alg. This guarantees the returned entry contains all the PCR selections for the given
 * hash alg, which may require modifying the TPML_PCR_SELECTION by removing duplicate entries. */
static TPMS_PCR_SELECTION *tpm2_tpml_pcr_selection_get_tpms_pcr_selection(
                TPML_PCR_SELECTION *l,
                TPMI_ALG_HASH hash_alg) {

        assert(l);
        assert(l->count <= ELEMENTSOF(l->pcrSelections));

        TPMS_PCR_SELECTION *selection = NULL;
        FOREACH_TPMS_PCR_SELECTION_IN_TPML_PCR_SELECTION(s, l)
                if (s->hash == hash_alg) {
                        selection = s;
                        break;
                }

        if (!selection)
                return NULL;

        /* Iterate backwards through the entries, removing any other entries for the hash alg. */
        for (uint32_t i = l->count - 1; i > 0; i--) {
                TPMS_PCR_SELECTION *s = &l->pcrSelections[i];

                if (selection == s)
                        break;

                if (s->hash == hash_alg) {
                        tpm2_tpms_pcr_selection_move(selection, s);
                        tpm2_tpml_pcr_selection_remove_index(l, i);
                }
        }

        return selection;
}

/* Combine all duplicate (same hash alg) TPMS_PCR_SELECTION entries in 'l'. */
static void tpm2_tpml_pcr_selection_cleanup(TPML_PCR_SELECTION *l) {
        /* Can't use FOREACH_TPMS_PCR_SELECTION_IN_TPML_PCR_SELECTION() because we might modify l->count */
        for (uint32_t i = 0; i < l->count; i++)
                /* This removes all duplicate TPMS_PCR_SELECTION entries for this hash. */
                (void) tpm2_tpml_pcr_selection_get_tpms_pcr_selection(l, l->pcrSelections[i].hash);
}

/* Convert a TPML_PCR_SELECTION object to a mask. Returns empty mask (i.e. 0) if 'hash_alg' is not in the object. */
uint32_t tpm2_tpml_pcr_selection_to_mask(const TPML_PCR_SELECTION *l, TPMI_ALG_HASH hash_alg) {
        assert(l);

        /* Make a copy, as tpm2_tpml_pcr_selection_get_tpms_pcr_selection() will modify the object if there
         * are multiple entries with the requested hash alg. */
        TPML_PCR_SELECTION lcopy = *l;

        TPMS_PCR_SELECTION *s;
        s = tpm2_tpml_pcr_selection_get_tpms_pcr_selection(&lcopy, hash_alg);
        if (!s)
                return 0;

        return tpm2_tpms_pcr_selection_to_mask(s);
}

/* Convert a mask and hash alg to a TPML_PCR_SELECTION object. */
void tpm2_tpml_pcr_selection_from_mask(uint32_t mask, TPMI_ALG_HASH hash_alg, TPML_PCR_SELECTION *ret) {
        assert(ret);

        TPMS_PCR_SELECTION s;
        tpm2_tpms_pcr_selection_from_mask(mask, hash_alg, &s);

        *ret = (TPML_PCR_SELECTION){
                .count = 1,
                .pcrSelections[0] = s,
        };
}

/* Add the PCR selections in 's' to the corresponding hash alg TPMS_PCR_SELECTION entry in 'l'. Adds a new
 * TPMS_PCR_SELECTION entry for the hash alg if needed. This may modify the TPML_PCR_SELECTION by combining
 * entries with the same hash alg. */
void tpm2_tpml_pcr_selection_add_tpms_pcr_selection(TPML_PCR_SELECTION *l, const TPMS_PCR_SELECTION *s) {
        assert(l);
        assert(s);

        if (tpm2_tpms_pcr_selection_is_empty(s))
                return;

        TPMS_PCR_SELECTION *selection = tpm2_tpml_pcr_selection_get_tpms_pcr_selection(l, s->hash);
        if (selection) {
                tpm2_tpms_pcr_selection_add(selection, s);
                return;
        }

        /* It's already broken if the count is higher than the array has size for. */
        assert(l->count <= ELEMENTSOF(l->pcrSelections));

        /* If full, the cleanup should result in at least one available entry. */
        if (l->count == ELEMENTSOF(l->pcrSelections))
                tpm2_tpml_pcr_selection_cleanup(l);

        assert(l->count < ELEMENTSOF(l->pcrSelections));
        l->pcrSelections[l->count++] = *s;
}

/* Remove the PCR selections in 's' from the corresponding hash alg TPMS_PCR_SELECTION entry in 'l'. This
 * will combine all entries for 's->hash' in 'l'. */
void tpm2_tpml_pcr_selection_sub_tpms_pcr_selection(TPML_PCR_SELECTION *l, const TPMS_PCR_SELECTION *s) {
        assert(l);
        assert(s);

        if (tpm2_tpms_pcr_selection_is_empty(s))
                return;

        TPMS_PCR_SELECTION *selection = tpm2_tpml_pcr_selection_get_tpms_pcr_selection(l, s->hash);
        if (selection)
                tpm2_tpms_pcr_selection_sub(selection, s);
}

/* Test if all bits in the mask for the hash are set in the TPML_PCR_SELECTION. */
bool tpm2_tpml_pcr_selection_has_mask(const TPML_PCR_SELECTION *l, TPMI_ALG_HASH hash, uint32_t mask) {
        assert(l);

        return FLAGS_SET(tpm2_tpml_pcr_selection_to_mask(l, hash), mask);
}

/* Add the PCR selections in the mask, with the provided hash. */
void tpm2_tpml_pcr_selection_add_mask(TPML_PCR_SELECTION *l, TPMI_ALG_HASH hash, uint32_t mask) {
        TPMS_PCR_SELECTION tpms;

        assert(l);

        tpm2_tpms_pcr_selection_from_mask(mask, hash, &tpms);
        tpm2_tpml_pcr_selection_add_tpms_pcr_selection(l, &tpms);
}

/* Remove the PCR selections in the mask, with the provided hash. */
void tpm2_tpml_pcr_selection_sub_mask(TPML_PCR_SELECTION *l, TPMI_ALG_HASH hash, uint32_t mask) {
        TPMS_PCR_SELECTION tpms;

        assert(l);

        tpm2_tpms_pcr_selection_from_mask(mask, hash, &tpms);
        tpm2_tpml_pcr_selection_sub_tpms_pcr_selection(l, &tpms);
}

/* Add all PCR selections in 'b' to 'a'. */
void tpm2_tpml_pcr_selection_add(TPML_PCR_SELECTION *a, const TPML_PCR_SELECTION *b) {
        assert(a);
        assert(b);

        FOREACH_TPMS_PCR_SELECTION_IN_TPML_PCR_SELECTION(selection_b, b)
                tpm2_tpml_pcr_selection_add_tpms_pcr_selection(a, selection_b);
}

/* Remove all PCR selections in 'b' from 'a'. */
void tpm2_tpml_pcr_selection_sub(TPML_PCR_SELECTION *a, const TPML_PCR_SELECTION *b) {
        assert(a);
        assert(b);

        FOREACH_TPMS_PCR_SELECTION_IN_TPML_PCR_SELECTION(selection_b, b)
                tpm2_tpml_pcr_selection_sub_tpms_pcr_selection(a, selection_b);
}

char *tpm2_tpml_pcr_selection_to_string(const TPML_PCR_SELECTION *l) {
        assert(l);

        _cleanup_free_ char *banks = NULL;
        FOREACH_TPMS_PCR_SELECTION_IN_TPML_PCR_SELECTION(s, l) {
                if (tpm2_tpms_pcr_selection_is_empty(s))
                        continue;

                _cleanup_free_ char *str = tpm2_tpms_pcr_selection_to_string(s);
                if (!str || !strextend_with_separator(&banks, ",", str))
                        return NULL;
        }

        return strjoin("[", strempty(banks), "]");
}

size_t tpm2_tpml_pcr_selection_weight(const TPML_PCR_SELECTION *l) {
        assert(l);
        assert(l->count <= ELEMENTSOF(l->pcrSelections));

        size_t weight = 0;
        FOREACH_TPMS_PCR_SELECTION_IN_TPML_PCR_SELECTION(s, l) {
                size_t w = tpm2_tpms_pcr_selection_weight(s);
                assert(weight <= SIZE_MAX - w);
                weight += w;
        }

        return weight;
}

bool tpm2_pcr_value_valid(const Tpm2PCRValue *pcr_value) {
        int r;

        if (!pcr_value)
                return false;

        if (!TPM2_PCR_INDEX_VALID(pcr_value->index)) {
                log_debug("PCR index %u invalid.", pcr_value->index);
                return false;
        }

        /* If it contains a value, the value size must match the hash size. */
        if (pcr_value->value.size > 0) {
                r = tpm2_hash_alg_to_size(pcr_value->hash);
                if (r < 0)
                        return false;

                if (pcr_value->value.size != (size_t) r) {
                        log_debug("PCR hash 0x%" PRIx16 " expected size %d does not match actual size %" PRIu16 ".",
                                  pcr_value->hash, r, pcr_value->value.size);
                        return false;
                }
        }

        return true;
}

/* Verify all entries are valid, and consistent with each other. The requirements for consistency are:
 *
 * 1) all entries must be sorted in ascending order (e.g. using tpm2_sort_pcr_values())
 * 2) all entries must be unique, i.e. there cannot be 2 entries with the same hash and index
 *
 * Returns true if all entries are valid (or if no entries are provided), false otherwise.
 */
bool tpm2_pcr_values_valid(const Tpm2PCRValue *pcr_values, size_t n_pcr_values) {
        if (!pcr_values && n_pcr_values > 0)
                return false;

        const Tpm2PCRValue *previous = NULL;
        FOREACH_ARRAY(current, pcr_values, n_pcr_values) {
                if (!tpm2_pcr_value_valid(current))
                        return false;

                if (!previous) {
                        previous = current;
                        continue;
                }

                /* Hashes must be sorted in ascending order */
                if (current->hash < previous->hash) {
                        log_debug("PCR values not in ascending order, hash %" PRIu16 " is after %" PRIu16 ".",
                                  current->hash, previous->hash);
                        return false;
                }

                if (current->hash == previous->hash) {
                        /* Indexes (for the same hash) must be sorted in ascending order */
                        if (current->index < previous->index) {
                                log_debug("PCR values not in ascending order, hash %" PRIu16 " index %u is after %u.",
                                          current->hash, current->index, previous->index);
                                return false;
                        }

                        /* Indexes (for the same hash) must not be duplicates */
                        if (current->index == previous->index) {
                                log_debug("PCR values contain duplicates for hash %" PRIu16 " index %u.",
                                          current->hash, previous->index);
                                return false;
                        }
                }
        }

        return true;
}

/* Returns true if any of the provided PCR values has an actual hash value included, false otherwise. */
bool tpm2_pcr_values_has_any_values(const Tpm2PCRValue *pcr_values, size_t n_pcr_values) {
        assert(pcr_values || n_pcr_values == 0);

        FOREACH_ARRAY(v, pcr_values, n_pcr_values)
                if (v->value.size > 0)
                        return true;

        return false;
}

/* Returns true if all of the provided PCR values has an actual hash value included, false otherwise. */
bool tpm2_pcr_values_has_all_values(const Tpm2PCRValue *pcr_values, size_t n_pcr_values) {
        assert(pcr_values || n_pcr_values == 0);

        FOREACH_ARRAY(v, pcr_values, n_pcr_values)
                if (v->value.size == 0)
                        return false;

        return true;
}

static int cmp_pcr_values(const Tpm2PCRValue *a, const Tpm2PCRValue *b) {
        assert(a);
        assert(b);

        return CMP(a->hash, b->hash) ?: CMP(a->index, b->index);
}

/* Sort the array of Tpm2PCRValue entries in-place. This sorts first in ascending order of hash algorithm
 * (sorting simply by the TPM2 hash algorithm number), and then sorting by pcr index. */
void tpm2_sort_pcr_values(Tpm2PCRValue *pcr_values, size_t n_pcr_values) {
        typesafe_qsort(pcr_values, n_pcr_values, cmp_pcr_values);
}

int tpm2_pcr_values_from_mask(uint32_t mask, TPMI_ALG_HASH hash, Tpm2PCRValue **ret_pcr_values, size_t *ret_n_pcr_values) {
        _cleanup_free_ Tpm2PCRValue *pcr_values = NULL;
        size_t n_pcr_values = 0;

        assert(ret_pcr_values);
        assert(ret_n_pcr_values);

        FOREACH_PCR_IN_MASK(index, mask)
                if (!GREEDY_REALLOC_APPEND(
                                pcr_values,
                                n_pcr_values,
                                &TPM2_PCR_VALUE_MAKE(index, hash, {}),
                                1))
                        return log_oom_debug();

        *ret_pcr_values = TAKE_PTR(pcr_values);
        *ret_n_pcr_values = n_pcr_values;

        return 0;
}

int tpm2_pcr_values_to_mask(const Tpm2PCRValue *pcr_values, size_t n_pcr_values, TPMI_ALG_HASH hash, uint32_t *ret_mask) {
        uint32_t mask = 0;

        assert(pcr_values || n_pcr_values == 0);
        assert(ret_mask);

        if (!tpm2_pcr_values_valid(pcr_values, n_pcr_values))
                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Invalid PCR values.");

        FOREACH_ARRAY(v, pcr_values, n_pcr_values)
                if (v->hash == hash)
                        SET_BIT(mask, v->index);

        *ret_mask = mask;

        return 0;
}

int tpm2_tpml_pcr_selection_from_pcr_values(
                const Tpm2PCRValue *pcr_values,
                size_t n_pcr_values,
                TPML_PCR_SELECTION *ret_selection,
                TPM2B_DIGEST **ret_values,
                size_t *ret_n_values) {

        TPML_PCR_SELECTION selection = {};
        _cleanup_free_ TPM2B_DIGEST *values = NULL;
        size_t n_values = 0;

        assert(pcr_values || n_pcr_values == 0);

        if (!tpm2_pcr_values_valid(pcr_values, n_pcr_values))
                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "PCR values are not valid.");

        FOREACH_ARRAY(v, pcr_values, n_pcr_values) {
                tpm2_tpml_pcr_selection_add_mask(&selection, v->hash, INDEX_TO_MASK(uint32_t, v->index));

                if (!GREEDY_REALLOC_APPEND(values, n_values, &v->value, 1))
                        return log_oom_debug();
        }

        if (ret_selection)
                *ret_selection = selection;
        if (ret_values)
                *ret_values = TAKE_PTR(values);
        if (ret_n_values)
                *ret_n_values = n_values;

        return 0;
}

/* Count the number of different hash algorithms for all the entries. */
int tpm2_pcr_values_hash_count(const Tpm2PCRValue *pcr_values, size_t n_pcr_values, size_t *ret_count) {
        TPML_PCR_SELECTION selection;
        int r;

        assert(pcr_values);
        assert(ret_count);

        r = tpm2_tpml_pcr_selection_from_pcr_values(
                        pcr_values,
                        n_pcr_values,
                        &selection,
                        /* ret_values= */ NULL,
                        /* ret_n_values= */ NULL);
        if (r < 0)
                return r;

        *ret_count = selection.count;

        return 0;
}

/* Parse a string argument into a Tpm2PCRValue object.
 *
 * The format is <index>[:hash[=value]] where index is the index number (or name) of the PCR, e.g. 0 (or
 * platform-code), hash is the name of the hash algorithm (e.g. sha256) and value is the hex hash digest
 * value, optionally with a leading 0x. This does not check for validity of the fields. */
int tpm2_pcr_value_from_string(const char *arg, Tpm2PCRValue *ret_pcr_value) {
        Tpm2PCRValue pcr_value = {};
        const char *p = arg;
        int r;

        assert(arg);
        assert(ret_pcr_value);

        _cleanup_free_ char *index = NULL;
        r = extract_first_word(&p, &index, ":", /* flags= */ 0);
        if (r < 1)
                return log_debug_errno(r, "Could not parse pcr value '%s': %m", p);

        r = tpm2_pcr_index_from_string(index);
        if (r < 0)
                return log_debug_errno(r, "Invalid pcr index '%s': %m", index);
        pcr_value.index = (unsigned) r;

        if (!isempty(p)) {
                _cleanup_free_ char *hash = NULL;
                r = extract_first_word(&p, &hash, "=", /* flags= */ 0);
                if (r < 1)
                        return log_debug_errno(r, "Could not parse pcr hash algorithm '%s': %m", p);

                r = tpm2_hash_alg_from_string(hash);
                if (r < 0)
                        return log_debug_errno(r, "Invalid pcr hash algorithm '%s': %m", hash);
                pcr_value.hash = (TPMI_ALG_HASH) r;

                if (!isempty(p)) {
                        /* Remove leading 0x if present */
                        p = startswith_no_case(p, "0x") ?: p;

                        _cleanup_free_ void *buf = NULL;
                        size_t buf_size = 0;
                        r = unhexmem(p, &buf, &buf_size);
                        if (r < 0)
                                return log_debug_errno(r, "Invalid pcr hash value '%s': %m", p);

                        r = TPM2B_DIGEST_CHECK_SIZE(buf_size);
                        if (r < 0)
                                return log_debug_errno(r, "PCR hash value size %zu too large.", buf_size);

                        pcr_value.value = TPM2B_DIGEST_MAKE(buf, buf_size);
                }
        }

        *ret_pcr_value = pcr_value;

        return 0;
}

/* Return a string for the PCR value. The format is described in tpm2_pcr_value_from_string(). Note that if
 * the hash algorithm is not recognized, neither hash name nor hash digest value is included in the
 * string. This does not check for validity. */
char *tpm2_pcr_value_to_string(const Tpm2PCRValue *pcr_value) {
        _cleanup_free_ char *index = NULL, *value = NULL;

        if (asprintf(&index, "%u", pcr_value->index) < 0)
                return NULL;

        const char *hash = pcr_value->hash > 0 ? tpm2_hash_alg_to_string(pcr_value->hash) : NULL;

        if (hash && pcr_value->value.size > 0) {
                value = hexmem(pcr_value->value.buffer, pcr_value->value.size);
                if (!value)
                        return NULL;
        }

        return strjoin(index, hash ? ":" : "", strempty(hash), value ? "=" : "", strempty(value));
}

/* Parse a string argument into an array of Tpm2PCRValue objects.
 *
 * The format is zero or more entries separated by ',' or '+'. The format of each entry is described in
 * tpm2_pcr_value_from_string(). This does not check for validity of the entries. */
int tpm2_pcr_values_from_string(const char *arg, Tpm2PCRValue **ret_pcr_values, size_t *ret_n_pcr_values) {
        const char *p = arg;
        int r;

        assert(arg);
        assert(ret_pcr_values);
        assert(ret_n_pcr_values);

        _cleanup_free_ Tpm2PCRValue *pcr_values = NULL;
        size_t n_pcr_values = 0;

        for (;;) {
                _cleanup_free_ char *pcr_arg = NULL;
                r = extract_first_word(&p, &pcr_arg, ",+", /* flags= */ 0);
                if (r < 0)
                        return log_debug_errno(r, "Could not parse pcr values '%s': %m", p);
                if (r == 0)
                        break;

                Tpm2PCRValue pcr_value;
                r = tpm2_pcr_value_from_string(pcr_arg, &pcr_value);
                if (r < 0)
                        return r;

                if (!GREEDY_REALLOC_APPEND(pcr_values, n_pcr_values, &pcr_value, 1))
                        return log_oom_debug();
        }

        *ret_pcr_values = TAKE_PTR(pcr_values);
        *ret_n_pcr_values = n_pcr_values;

        return 0;
}

/* Return a string representing the array of PCR values. The format is as described in
 * tpm2_pcr_values_from_string(). This does not check for validity. */
char *tpm2_pcr_values_to_string(const Tpm2PCRValue *pcr_values, size_t n_pcr_values) {
        _cleanup_free_ char *s = NULL;

        FOREACH_ARRAY(v, pcr_values, n_pcr_values) {
                _cleanup_free_ char *pcrstr = tpm2_pcr_value_to_string(v);
                if (!pcrstr || !strextend_with_separator(&s, "+", pcrstr))
                        return NULL;
        }

        return s ? TAKE_PTR(s) : strdup("");
}

void tpm2_log_debug_tpml_pcr_selection(const TPML_PCR_SELECTION *l, const char *msg) {
        if (!DEBUG_LOGGING || !l)
                return;

        _cleanup_free_ char *s = tpm2_tpml_pcr_selection_to_string(l);
        log_debug("%s: %s", msg ?: "PCR selection", strna(s));
}

void tpm2_log_debug_pcr_value(const Tpm2PCRValue *pcr_value, const char *msg) {
        if (!DEBUG_LOGGING || !pcr_value)
                return;

        _cleanup_free_ char *s = tpm2_pcr_value_to_string(pcr_value);
        log_debug("%s: %s", msg ?: "PCR value", strna(s));
}

void tpm2_log_debug_buffer(const void *buffer, size_t size, const char *msg) {
        if (!DEBUG_LOGGING || !buffer || size == 0)
                return;

        _cleanup_free_ char *h = hexmem(buffer, size);
        log_debug("%s: %s", msg ?: "Buffer", strna(h));
}

void tpm2_log_debug_digest(const TPM2B_DIGEST *digest, const char *msg) {
        if (digest)
                tpm2_log_debug_buffer(digest->buffer, digest->size, msg ?: "Digest");
}

void tpm2_log_debug_name(const TPM2B_NAME *name, const char *msg) {
        if (name)
                tpm2_log_debug_buffer(name->name, name->size, msg ?: "Name");
}

static int tpm2_get_policy_digest(
                Tpm2Context *c,
                const Tpm2Handle *session,
                TPM2B_DIGEST **ret_policy_digest) {

        TSS2_RC rc;

        if (!DEBUG_LOGGING && !ret_policy_digest)
                return 0;

        assert(c);
        assert(session);

        log_debug("Acquiring policy digest.");

        _cleanup_(Esys_Freep) TPM2B_DIGEST *policy_digest = NULL;
        rc = sym_Esys_PolicyGetDigest(
                        c->esys_context,
                        session->esys_handle,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        &policy_digest);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to get policy digest from TPM: %s", sym_Tss2_RC_Decode(rc));

        tpm2_log_debug_digest(policy_digest, "Session policy digest");

        if (ret_policy_digest)
                *ret_policy_digest = TAKE_PTR(policy_digest);

        return 0;
}

int tpm2_create_primary(
                Tpm2Context *c,
                const Tpm2Handle *session,
                const TPM2B_PUBLIC *template,
                const TPM2B_SENSITIVE_CREATE *sensitive,
                TPM2B_PUBLIC **ret_public,
                Tpm2Handle **ret_handle) {

        usec_t ts;
        TSS2_RC rc;
        int r;

        assert(c);
        assert(template);

        log_debug("Creating primary key on TPM.");

        ts = now(CLOCK_MONOTONIC);

        _cleanup_(tpm2_handle_freep) Tpm2Handle *handle = NULL;
        r = tpm2_handle_new(c, &handle);
        if (r < 0)
                return r;

        _cleanup_(Esys_Freep) TPM2B_PUBLIC *public = NULL;
        rc = sym_Esys_CreatePrimary(
                        c->esys_context,
                        ESYS_TR_RH_OWNER,
                        session ? session->esys_handle : ESYS_TR_PASSWORD,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        sensitive ?: &(TPM2B_SENSITIVE_CREATE) {},
                        template,
                        /* outsideInfo= */ NULL,
                        &(TPML_PCR_SELECTION) {},
                        &handle->esys_handle,
                        &public,
                        /* creationData= */ NULL,
                        /* creationHash= */ NULL,
                        /* creationTicket= */ NULL);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to generate primary key in TPM: %s",
                                       sym_Tss2_RC_Decode(rc));

        log_debug("Successfully created primary key on TPM in %s.",
                  FORMAT_TIMESPAN(now(CLOCK_MONOTONIC) - ts, USEC_PER_MSEC));

        if (ret_public)
                *ret_public = TAKE_PTR(public);
        if (ret_handle)
                *ret_handle = TAKE_PTR(handle);

        return 0;
}

/* Create a TPM object. Do not use this to create primary keys, because some HW TPMs refuse to allow that;
 * instead use tpm2_create_primary(). */
int tpm2_create(Tpm2Context *c,
                const Tpm2Handle *parent,
                const Tpm2Handle *session,
                const TPMT_PUBLIC *template,
                const TPMS_SENSITIVE_CREATE *sensitive,
                TPM2B_PUBLIC **ret_public,
                TPM2B_PRIVATE **ret_private) {

        usec_t ts;
        TSS2_RC rc;

        assert(c);
        assert(parent);
        assert(template);

        log_debug("Creating object on TPM.");

        ts = now(CLOCK_MONOTONIC);

        TPM2B_PUBLIC tpm2b_public = {
                .size = sizeof(*template) - sizeof(template->unique),
                .publicArea = *template,
        };

        /* Zero the unique area. */
        zero(tpm2b_public.publicArea.unique);

        TPM2B_SENSITIVE_CREATE tpm2b_sensitive;
        if (sensitive)
                tpm2b_sensitive = (TPM2B_SENSITIVE_CREATE) {
                        .size = sizeof(*sensitive),
                        .sensitive = *sensitive,
                };
        else
                tpm2b_sensitive = (TPM2B_SENSITIVE_CREATE) {};

        _cleanup_(Esys_Freep) TPM2B_PUBLIC *public = NULL;
        _cleanup_(Esys_Freep) TPM2B_PRIVATE *private = NULL;
        rc = sym_Esys_Create(
                        c->esys_context,
                        parent->esys_handle,
                        session ? session->esys_handle : ESYS_TR_PASSWORD,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        &tpm2b_sensitive,
                        &tpm2b_public,
                        /* outsideInfo= */ NULL,
                        &(TPML_PCR_SELECTION) {},
                        &private,
                        &public,
                        /* creationData= */ NULL,
                        /* creationHash= */ NULL,
                        /* creationTicket= */ NULL);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to generate object in TPM: %s",
                                       sym_Tss2_RC_Decode(rc));

        log_debug("Successfully created object on TPM in %s.",
                  FORMAT_TIMESPAN(now(CLOCK_MONOTONIC) - ts, USEC_PER_MSEC));

        if (ret_public)
                *ret_public = TAKE_PTR(public);
        if (ret_private)
                *ret_private = TAKE_PTR(private);

        return 0;
}

int tpm2_load(
                Tpm2Context *c,
                const Tpm2Handle *parent,
                const Tpm2Handle *session,
                const TPM2B_PUBLIC *public,
                const TPM2B_PRIVATE *private,
                Tpm2Handle **ret_handle) {

        TSS2_RC rc;
        int r;

        assert(c);
        assert(public);
        assert(private);
        assert(ret_handle);

        log_debug("Loading object into TPM.");

        _cleanup_(tpm2_handle_freep) Tpm2Handle *handle = NULL;
        r = tpm2_handle_new(c, &handle);
        if (r < 0)
                return r;

        rc = sym_Esys_Load(
                        c->esys_context,
                        parent ? parent->esys_handle : ESYS_TR_RH_OWNER,
                        session ? session->esys_handle : ESYS_TR_PASSWORD,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        private,
                        public,
                        &handle->esys_handle);
        if (rc == TPM2_RC_LOCKOUT)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOLCK),
                                       "TPM2 device is in dictionary attack lockout mode.");
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to load key into TPM: %s", sym_Tss2_RC_Decode(rc));

        *ret_handle = TAKE_PTR(handle);

        return 0;
}

static int tpm2_load_external(
                Tpm2Context *c,
                const Tpm2Handle *session,
                const TPM2B_PUBLIC *public,
                const TPM2B_SENSITIVE *private,
                Tpm2Handle **ret_handle) {

        TSS2_RC rc;
        int r;

        assert(c);
        assert(ret_handle);

        log_debug("Loading external key into TPM.");

        _cleanup_(tpm2_handle_freep) Tpm2Handle *handle = NULL;
        r = tpm2_handle_new(c, &handle);
        if (r < 0)
                return r;

        rc = sym_Esys_LoadExternal(
                        c->esys_context,
                        session ? session->esys_handle : ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        private,
                        public,
#if HAVE_TSS2_ESYS3
                        /* tpm2-tss >= 3.0.0 requires a ESYS_TR_RH_* constant specifying the requested
                         * hierarchy, older versions need TPM2_RH_* instead. */
                        private ? ESYS_TR_RH_NULL : ESYS_TR_RH_OWNER,
#else
                        private ? TPM2_RH_NULL : TPM2_RH_OWNER,
#endif
                        &handle->esys_handle);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to load public key into TPM: %s", sym_Tss2_RC_Decode(rc));

        *ret_handle = TAKE_PTR(handle);

        return 0;
}

/* This calls TPM2_CreateLoaded() directly, without checking if the TPM supports it. Callers should instead
 * use tpm2_create_loaded(). */
static int _tpm2_create_loaded(
                Tpm2Context *c,
                const Tpm2Handle *parent,
                const Tpm2Handle *session,
                const TPMT_PUBLIC *template,
                const TPMS_SENSITIVE_CREATE *sensitive,
                TPM2B_PUBLIC **ret_public,
                TPM2B_PRIVATE **ret_private,
                Tpm2Handle **ret_handle) {

        usec_t ts;
        TSS2_RC rc;
        int r;

        assert(c);
        assert(parent);
        assert(template);

        log_debug("Creating loaded object on TPM.");

        ts = now(CLOCK_MONOTONIC);

        /* Copy the input template and zero the unique area. */
        TPMT_PUBLIC template_copy = *template;
        zero(template_copy.unique);

        TPM2B_TEMPLATE tpm2b_template;
        size_t size = 0;
        rc = sym_Tss2_MU_TPMT_PUBLIC_Marshal(
                        &template_copy,
                        tpm2b_template.buffer,
                        sizeof(tpm2b_template.buffer),
                        &size);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal public key template: %s", sym_Tss2_RC_Decode(rc));
        assert(size <= UINT16_MAX);
        tpm2b_template.size = size;

        TPM2B_SENSITIVE_CREATE tpm2b_sensitive;
        if (sensitive)
                tpm2b_sensitive = (TPM2B_SENSITIVE_CREATE) {
                        .size = sizeof(*sensitive),
                        .sensitive = *sensitive,
                };
        else
                tpm2b_sensitive = (TPM2B_SENSITIVE_CREATE) {};

        _cleanup_(tpm2_handle_freep) Tpm2Handle *handle = NULL;
        r = tpm2_handle_new(c, &handle);
        if (r < 0)
                return r;

        _cleanup_(Esys_Freep) TPM2B_PUBLIC *public = NULL;
        _cleanup_(Esys_Freep) TPM2B_PRIVATE *private = NULL;
        rc = sym_Esys_CreateLoaded(
                        c->esys_context,
                        parent->esys_handle,
                        session ? session->esys_handle : ESYS_TR_PASSWORD,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        &tpm2b_sensitive,
                        &tpm2b_template,
                        &handle->esys_handle,
                        &private,
                        &public);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to generate loaded object in TPM: %s",
                                       sym_Tss2_RC_Decode(rc));

        log_debug("Successfully created loaded object on TPM in %s.",
                  FORMAT_TIMESPAN(now(CLOCK_MONOTONIC) - ts, USEC_PER_MSEC));

        if (ret_public)
                *ret_public = TAKE_PTR(public);
        if (ret_private)
                *ret_private = TAKE_PTR(private);
        if (ret_handle)
                *ret_handle = TAKE_PTR(handle);

        return 0;
}

/* This calls TPM2_CreateLoaded() if the TPM supports it, otherwise it calls TPM2_Create() and TPM2_Load()
 * separately. Do not use this to create primary keys, because some HW TPMs refuse to allow that; instead use
 * tpm2_create_primary(). */
int tpm2_create_loaded(
                Tpm2Context *c,
                const Tpm2Handle *parent,
                const Tpm2Handle *session,
                const TPMT_PUBLIC *template,
                const TPMS_SENSITIVE_CREATE *sensitive,
                TPM2B_PUBLIC **ret_public,
                TPM2B_PRIVATE **ret_private,
                Tpm2Handle **ret_handle) {

        int r;

        if (tpm2_supports_command(c, TPM2_CC_CreateLoaded))
                return _tpm2_create_loaded(c, parent, session, template, sensitive, ret_public, ret_private, ret_handle);

        /* Unfortunately, this TPM doesn't support CreateLoaded (added at spec revision 130) so we need to
         * create and load manually. */
        _cleanup_(Esys_Freep) TPM2B_PUBLIC *public = NULL;
        _cleanup_(Esys_Freep) TPM2B_PRIVATE *private = NULL;
        r = tpm2_create(c, parent, session, template, sensitive, &public, &private);
        if (r < 0)
                return r;

        _cleanup_(tpm2_handle_freep) Tpm2Handle *handle = NULL;
        r = tpm2_load(c, parent, session, public, private, &handle);
        if (r < 0)
                return r;

        if (ret_public)
                *ret_public = TAKE_PTR(public);
        if (ret_private)
                *ret_private = TAKE_PTR(private);
        if (ret_handle)
                *ret_handle = TAKE_PTR(handle);

        return 0;
}

static int tpm2_marshal_private(const TPM2B_PRIVATE *private, void **ret, size_t *ret_size) {
        size_t max_size = sizeof(*private), blob_size = 0;
        _cleanup_free_ void *blob = NULL;
        TSS2_RC rc;

        assert(private);
        assert(ret);
        assert(ret_size);

        blob = malloc0(max_size);
        if (!blob)
                return log_oom_debug();

        rc = sym_Tss2_MU_TPM2B_PRIVATE_Marshal(private, blob, max_size, &blob_size);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal private key: %s", sym_Tss2_RC_Decode(rc));

        *ret = TAKE_PTR(blob);
        *ret_size = blob_size;
        return 0;
}

static int tpm2_unmarshal_private(const void *data, size_t size, TPM2B_PRIVATE *ret_private) {
        TPM2B_PRIVATE private = {};
        size_t offset = 0;
        TSS2_RC rc;

        assert(data || size == 0);
        assert(ret_private);

        rc = sym_Tss2_MU_TPM2B_PRIVATE_Unmarshal(data, size, &offset, &private);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to unmarshal private key: %s", sym_Tss2_RC_Decode(rc));
        if (offset != size)
                return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Garbage at end of private key marshal data.");

        *ret_private = private;
        return 0;
}

int tpm2_marshal_public(const TPM2B_PUBLIC *public, void **ret, size_t *ret_size) {
        size_t max_size = sizeof(*public), blob_size = 0;
        _cleanup_free_ void *blob = NULL;
        TSS2_RC rc;

        assert(public);
        assert(ret);
        assert(ret_size);

        blob = malloc0(max_size);
        if (!blob)
                return log_oom_debug();

        rc = sym_Tss2_MU_TPM2B_PUBLIC_Marshal(public, blob, max_size, &blob_size);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal public key: %s", sym_Tss2_RC_Decode(rc));

        *ret = TAKE_PTR(blob);
        *ret_size = blob_size;
        return 0;
}

static int tpm2_unmarshal_public(const void *data, size_t size, TPM2B_PUBLIC *ret_public) {
        TPM2B_PUBLIC public = {};
        size_t offset = 0;
        TSS2_RC rc;

        assert(data || size == 0);
        assert(ret_public);

        rc = sym_Tss2_MU_TPM2B_PUBLIC_Unmarshal(data, size, &offset, &public);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to unmarshal public key: %s", sym_Tss2_RC_Decode(rc));
        if (offset != size)
                return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Garbage at end of public key marshal data.");

        *ret_public = public;
        return 0;
}

int tpm2_marshal_nv_public(const TPM2B_NV_PUBLIC *nv_public, void **ret, size_t *ret_size) {
        size_t max_size = sizeof(*nv_public), blob_size = 0;
        _cleanup_free_ void *blob = NULL;
        TSS2_RC rc;

        assert(nv_public);
        assert(ret);
        assert(ret_size);

        blob = malloc0(max_size);
        if (!blob)
                return log_oom_debug();

        rc = sym_Tss2_MU_TPM2B_NV_PUBLIC_Marshal(nv_public, blob, max_size, &blob_size);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal NV public structure: %s", sym_Tss2_RC_Decode(rc));

        *ret = TAKE_PTR(blob);
        *ret_size = blob_size;
        return 0;
}

int tpm2_unmarshal_nv_public(const void *data, size_t size, TPM2B_NV_PUBLIC *ret_nv_public) {
        TPM2B_NV_PUBLIC nv_public = {};
        size_t offset = 0;
        TSS2_RC rc;

        assert(data || size == 0);
        assert(ret_nv_public);

        rc = sym_Tss2_MU_TPM2B_NV_PUBLIC_Unmarshal(data, size, &offset, &nv_public);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to unmarshal NV public structure: %s", sym_Tss2_RC_Decode(rc));
        if (offset != size)
                return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Garbage at end of NV public structure marshal data.");

        *ret_nv_public = nv_public;
        return 0;
}

static int tpm2_import(
                Tpm2Context *c,
                const Tpm2Handle *parent,
                const Tpm2Handle *session,
                const TPM2B_PUBLIC *public,
                const TPM2B_PRIVATE *private,
                const TPM2B_ENCRYPTED_SECRET *seed,
                const TPM2B_DATA *encryption_key,
                const TPMT_SYM_DEF_OBJECT *symmetric,
                TPM2B_PRIVATE **ret_private) {

        TSS2_RC rc;

        assert(c);
        assert(parent);
        assert(!!encryption_key == !!symmetric);
        assert(public);
        assert(private);
        assert(seed);
        assert(ret_private);

        log_debug("Importing key into TPM.");

        rc = sym_Esys_Import(
                        c->esys_context,
                        parent->esys_handle,
                        session ? session->esys_handle : ESYS_TR_PASSWORD,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        encryption_key,
                        public,
                        private,
                        seed,
                        symmetric ?: &(TPMT_SYM_DEF_OBJECT){ .algorithm = TPM2_ALG_NULL, },
                        ret_private);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to import key into TPM: %s", sym_Tss2_RC_Decode(rc));

        return 0;
}

/* Read hash values from the specified PCR selection. Provides a Tpm2PCRValue array that contains all
 * requested PCR values, in the order provided by the TPM. Normally, the provided pcr values will match
 * exactly what is in the provided selection, but the TPM may ignore some selected PCRs (for example, if an
 * unimplemented PCR index is requested), in which case those PCRs will be absent from the provided pcr
 * values. */
int tpm2_pcr_read(
                Tpm2Context *c,
                const TPML_PCR_SELECTION *pcr_selection,
                Tpm2PCRValue **ret_pcr_values,
                size_t *ret_n_pcr_values) {

        _cleanup_free_ Tpm2PCRValue *pcr_values = NULL;
        size_t n_pcr_values = 0;
        TSS2_RC rc;

        assert(c);
        assert(pcr_selection);
        assert(ret_pcr_values);
        assert(ret_n_pcr_values);

        TPML_PCR_SELECTION remaining = *pcr_selection;
        while (!tpm2_tpml_pcr_selection_is_empty(&remaining)) {
                _cleanup_(Esys_Freep) TPML_PCR_SELECTION *current_read = NULL;
                _cleanup_(Esys_Freep) TPML_DIGEST *current_values = NULL;

                tpm2_log_debug_tpml_pcr_selection(&remaining, "Reading PCR selection");

                /* Unfortunately, PCR_Read will not return more than 8 values. */
                rc = sym_Esys_PCR_Read(
                                c->esys_context,
                                ESYS_TR_NONE,
                                ESYS_TR_NONE,
                                ESYS_TR_NONE,
                                &remaining,
                                NULL,
                                &current_read,
                                &current_values);
                if (rc != TSS2_RC_SUCCESS)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                               "Failed to read TPM2 PCRs: %s", sym_Tss2_RC_Decode(rc));

                tpm2_log_debug_tpml_pcr_selection(current_read, "Read PCR selection");

                if (tpm2_tpml_pcr_selection_is_empty(current_read)) {
                        log_debug("TPM2 refused to read possibly unimplemented PCRs, ignoring.");
                        break;
                }

                unsigned i = 0;
                FOREACH_PCR_IN_TPML_PCR_SELECTION(index, tpms, current_read) {
                        assert(i < current_values->count);
                        Tpm2PCRValue pcr_value = {
                                .index = index,
                                .hash = tpms->hash,
                                .value = current_values->digests[i++],
                        };

                        tpm2_log_debug_pcr_value(&pcr_value, /* msg= */ NULL);

                        if (!GREEDY_REALLOC_APPEND(pcr_values, n_pcr_values, &pcr_value, 1))
                                return log_oom_debug();
                }
                assert(i == current_values->count);

                tpm2_tpml_pcr_selection_sub(&remaining, current_read);
        }

        tpm2_sort_pcr_values(pcr_values, n_pcr_values);

        if (!tpm2_pcr_values_valid(pcr_values, n_pcr_values))
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "PCR values read from TPM are not valid.");

        *ret_pcr_values = TAKE_PTR(pcr_values);
        *ret_n_pcr_values = n_pcr_values;

        return 0;
}

/* Read the PCR value for each TPM2PCRValue entry in the array that does not have a value set. If all entries
 * have an unset hash (i.e. hash == 0), this first detects the "best" PCR bank to use; otherwise, all entries
 * must have a valid hash set. All entries must have a valid index. If this cannot read a PCR value for all
 * appropriate entries, this returns an error. This does not check the array for validity. */
int tpm2_pcr_read_missing_values(Tpm2Context *c, Tpm2PCRValue *pcr_values, size_t n_pcr_values) {
        TPMI_ALG_HASH pcr_bank = 0;
        int r;

        assert(c);
        assert(pcr_values || n_pcr_values == 0);

        if (n_pcr_values > 0) {
                size_t hash_count;
                r = tpm2_pcr_values_hash_count(pcr_values, n_pcr_values, &hash_count);
                if (r < 0)
                        return log_debug_errno(r, "Could not get hash count from pcr values: %m");

                if (hash_count == 1 && pcr_values[0].hash == 0) {
                        uint32_t mask;
                        r = tpm2_pcr_values_to_mask(pcr_values, n_pcr_values, 0, &mask);
                        if (r < 0)
                                return r;

                        r = tpm2_get_best_pcr_bank(c, mask, &pcr_bank);
                        if (r < 0)
                                return r;
                }
        }

        FOREACH_ARRAY(v, pcr_values, n_pcr_values) {
                if (v->hash == 0)
                        v->hash = pcr_bank;

                if (v->value.size > 0)
                        continue;

                TPML_PCR_SELECTION selection;
                r = tpm2_tpml_pcr_selection_from_pcr_values(v, 1, &selection, NULL, NULL);
                if (r < 0)
                        return r;

                _cleanup_free_ Tpm2PCRValue *read_values = NULL;
                size_t n_read_values;
                r = tpm2_pcr_read(c, &selection, &read_values, &n_read_values);
                if (r < 0)
                        return r;

                if (n_read_values == 0)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                               "Could not read PCR hash 0x%" PRIu16 " index %u",
                                               v->hash, v->index);

                assert(n_read_values == 1);
                assert(read_values[0].hash == v->hash);
                assert(read_values[0].index == v->index);

                v->value = read_values[0].value;
        }

        return 0;
}

static int tpm2_pcr_mask_good(
                Tpm2Context *c,
                TPMI_ALG_HASH bank,
                uint32_t mask) {

        TPML_PCR_SELECTION selection;
        int r;

        assert(c);

        /* So we have the problem that some systems might have working TPM2 chips, but the firmware doesn't
         * actually measure into them, or only into a suboptimal bank. If so, the PCRs should be all zero or
         * all 0xFF. Detect that, so that we can warn and maybe pick a better bank. */

        tpm2_tpml_pcr_selection_from_mask(mask, bank, &selection);

        _cleanup_free_ Tpm2PCRValue *pcr_values = NULL;
        size_t n_pcr_values;
        r = tpm2_pcr_read(c, &selection, &pcr_values, &n_pcr_values);
        if (r < 0)
                return r;

        /* If at least one of the selected PCR values is something other than all 0x00 or all 0xFF we are happy. */
        FOREACH_ARRAY(v, pcr_values, n_pcr_values)
                if (!memeqbyte(0x00, v->value.buffer, v->value.size) &&
                    !memeqbyte(0xFF, v->value.buffer, v->value.size))
                        return true;

        return false;
}

static int tpm2_bank_has24(const TPMS_PCR_SELECTION *selection) {

        assert(selection);

        /* As per https://trustedcomputinggroup.org/wp-content/uploads/TCG_PCClient_PFP_r1p05_v23_pub.pdf a
         * TPM2 on a Client PC must have at least 24 PCRs. If this TPM has less, just skip over it. */
        if (selection->sizeofSelect < TPM2_PCRS_MAX/8) {
                log_debug("Skipping TPM2 PCR bank %s with fewer than 24 PCRs.",
                          strna(tpm2_hash_alg_to_string(selection->hash)));
                return false;
        }

        assert_cc(TPM2_PCRS_MAX % 8 == 0);

        /* It's not enough to check how many PCRs there are, we also need to check that the 24 are
         * enabled for this bank. Otherwise this TPM doesn't qualify. */
        bool valid = true;
        for (size_t j = 0; j < TPM2_PCRS_MAX/8; j++)
                if (selection->pcrSelect[j] != 0xFF) {
                        valid = false;
                        break;
                }

        if (!valid)
                log_debug("TPM2 PCR bank %s has fewer than 24 PCR bits enabled, ignoring.",
                          strna(tpm2_hash_alg_to_string(selection->hash)));

        return valid;
}

int tpm2_get_best_pcr_bank(
                Tpm2Context *c,
                uint32_t pcr_mask,
                TPMI_ALG_HASH *ret) {

        TPMI_ALG_HASH supported_hash = 0, hash_with_valid_pcr = 0;
        int r;

        assert(c);
        assert(ret);

        if (pcr_mask == 0) {
                log_debug("Asked to pick best PCR bank but no PCRs selected we could derive this from. Defaulting to SHA256.");
                *ret = TPM2_ALG_SHA256; /* if no PCRs are selected this doesn't matter anyway... */
                return 0;
        }

        FOREACH_TPMS_PCR_SELECTION_IN_TPML_PCR_SELECTION(selection, &c->capability_pcrs) {
                TPMI_ALG_HASH hash = selection->hash;
                int good;

                /* For now we are only interested in the SHA1 and SHA256 banks */
                if (!IN_SET(hash, TPM2_ALG_SHA256, TPM2_ALG_SHA1))
                        continue;

                r = tpm2_bank_has24(selection);
                if (r < 0)
                        return r;
                if (!r)
                        continue;

                good = tpm2_pcr_mask_good(c, hash, pcr_mask);
                if (good < 0)
                        return good;

                if (hash == TPM2_ALG_SHA256) {
                        supported_hash = TPM2_ALG_SHA256;
                        if (good) {
                                /* Great, SHA256 is supported and has initialized PCR values, we are done. */
                                hash_with_valid_pcr = TPM2_ALG_SHA256;
                                break;
                        }
                } else {
                        assert(hash == TPM2_ALG_SHA1);

                        if (supported_hash == 0)
                                supported_hash = TPM2_ALG_SHA1;

                        if (good && hash_with_valid_pcr == 0)
                                hash_with_valid_pcr = TPM2_ALG_SHA1;
                }
        }

        /* We preferably pick SHA256, but only if its PCRs are initialized or neither the SHA1 nor the SHA256
         * PCRs are initialized. If SHA256 is not supported but SHA1 is and its PCRs are too, we prefer
         * SHA1.
         *
         * We log at LOG_NOTICE level whenever we end up using the SHA1 bank or when the PCRs we bind to are
         * not initialized. */

        if (hash_with_valid_pcr == TPM2_ALG_SHA256) {
                assert(supported_hash == TPM2_ALG_SHA256);
                log_debug("TPM2 device supports SHA256 PCR bank and SHA256 PCRs are valid, yay!");
                *ret = TPM2_ALG_SHA256;
        } else if (hash_with_valid_pcr == TPM2_ALG_SHA1) {
                if (supported_hash == TPM2_ALG_SHA256)
                        log_notice("TPM2 device supports both SHA1 and SHA256 PCR banks, but only SHA1 PCRs are valid, falling back to SHA1 bank. This reduces the security level substantially.");
                else {
                        assert(supported_hash == TPM2_ALG_SHA1);
                        log_notice("TPM2 device lacks support for SHA256 PCR bank, but SHA1 bank is supported and SHA1 PCRs are valid, falling back to SHA1 bank. This reduces the security level substantially.");
                }

                *ret = TPM2_ALG_SHA1;
        } else if (supported_hash == TPM2_ALG_SHA256) {
                log_notice("TPM2 device supports SHA256 PCR bank but none of the selected PCRs are valid! Firmware apparently did not initialize any of the selected PCRs. Proceeding anyway with SHA256 bank. PCR policy effectively unenforced!");
                *ret = TPM2_ALG_SHA256;
        } else if (supported_hash == TPM2_ALG_SHA1) {
                log_notice("TPM2 device lacks support for SHA256 bank, but SHA1 bank is supported, but none of the selected PCRs are valid! Firmware apparently did not initialize any of the selected PCRs. Proceeding anyway with SHA1 bank. PCR policy effectively unenforced!");
                *ret = TPM2_ALG_SHA1;
        } else
                return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
                                       "TPM2 module supports neither SHA1 nor SHA256 PCR banks, cannot operate.");

        return 0;
}

int tpm2_get_good_pcr_banks(
                Tpm2Context *c,
                uint32_t pcr_mask,
                TPMI_ALG_HASH **ret) {

        _cleanup_free_ TPMI_ALG_HASH *good_banks = NULL, *fallback_banks = NULL;
        size_t n_good_banks = 0, n_fallback_banks = 0;
        int r;

        assert(c);
        assert(ret);

        FOREACH_TPMS_PCR_SELECTION_IN_TPML_PCR_SELECTION(selection, &c->capability_pcrs) {
                TPMI_ALG_HASH hash = selection->hash;

                /* Let's see if this bank is superficially OK, i.e. has at least 24 enabled registers */
                r = tpm2_bank_has24(selection);
                if (r < 0)
                        return r;
                if (!r)
                        continue;

                /* Let's now see if this bank has any of the selected PCRs actually initialized */
                r = tpm2_pcr_mask_good(c, hash, pcr_mask);
                if (r < 0)
                        return r;

                if (n_good_banks + n_fallback_banks >= INT_MAX)
                        return log_debug_errno(SYNTHETIC_ERRNO(E2BIG), "Too many good TPM2 banks?");

                if (r) {
                        if (!GREEDY_REALLOC(good_banks, n_good_banks+1))
                                return log_oom_debug();

                        good_banks[n_good_banks++] = hash;
                } else {
                        if (!GREEDY_REALLOC(fallback_banks, n_fallback_banks+1))
                                return log_oom_debug();

                        fallback_banks[n_fallback_banks++] = hash;
                }
        }

        /* Preferably, use the good banks (i.e. the ones the PCR values are actually initialized so
         * far). Otherwise use the fallback banks (i.e. which exist and are enabled, but so far not used. */
        if (n_good_banks > 0) {
                log_debug("Found %zu fully initialized TPM2 banks.", n_good_banks);
                *ret = TAKE_PTR(good_banks);
                return (int) n_good_banks;
        }
        if (n_fallback_banks > 0) {
                log_debug("Found %zu enabled but un-initialized TPM2 banks.", n_fallback_banks);
                *ret = TAKE_PTR(fallback_banks);
                return (int) n_fallback_banks;
        }

        /* No suitable banks found. */
        *ret = NULL;
        return 0;
}

int tpm2_get_good_pcr_banks_strv(
                Tpm2Context *c,
                uint32_t pcr_mask,
                char ***ret) {

#if HAVE_OPENSSL
        _cleanup_free_ TPMI_ALG_HASH *algs = NULL;
        _cleanup_strv_free_ char **l = NULL;
        int n_algs;

        assert(c);
        assert(ret);

        n_algs = tpm2_get_good_pcr_banks(c, pcr_mask, &algs);
        if (n_algs < 0)
                return n_algs;

        FOREACH_ARRAY(a, algs, n_algs) {
                _cleanup_free_ char *n = NULL;
                const EVP_MD *implementation;
                const char *salg;

                salg = tpm2_hash_alg_to_string(*a);
                if (!salg)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "TPM2 operates with unknown PCR algorithm, can't measure.");

                implementation = EVP_get_digestbyname(salg);
                if (!implementation)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "TPM2 operates with unsupported PCR algorithm, can't measure.");

                n = strdup(ASSERT_PTR(EVP_MD_name(implementation)));
                if (!n)
                        return log_oom_debug();

                ascii_strlower(n); /* OpenSSL uses uppercase digest names, we prefer them lower case. */

                if (strv_consume(&l, TAKE_PTR(n)) < 0)
                        return log_oom_debug();
        }

        *ret = TAKE_PTR(l);
        return 0;
#else /* HAVE_OPENSSL */
        return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "OpenSSL support is disabled.");
#endif
}

/* Hash data into the digest.
 *
 * If 'extend' is true, the hashing operation starts with the existing digest hash (and the digest is
 * required to have a hash and its size must be correct). If 'extend' is false, the digest size is
 * initialized to the correct size for 'alg' and the hashing operation does not include any existing digest
 * hash. If 'extend' is false and no data is provided, the digest is initialized to a zero digest.
 *
 * On success, the digest hash will be updated with the hashing operation result and the digest size will be
 * correct for 'alg'.
 *
 * This currently only provides SHA256, so 'alg' must be TPM2_ALG_SHA256. */
int tpm2_digest_many(
                TPMI_ALG_HASH alg,
                TPM2B_DIGEST *digest,
                const struct iovec data[],
                size_t n_data,
                bool extend) {

        struct sha256_ctx ctx;

        assert(digest);
        assert(data || n_data == 0);

        if (alg != TPM2_ALG_SHA256)
                return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
                                       "Hash algorithm not supported: 0x%x", alg);

        if (extend && digest->size != SHA256_DIGEST_SIZE)
                return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
                                       "Digest size 0x%x, require 0x%x",
                                       digest->size, (unsigned)SHA256_DIGEST_SIZE);

        /* Since we're hardcoding SHA256 (for now), we can check this at compile time. */
        assert_cc(sizeof(digest->buffer) >= SHA256_DIGEST_SIZE);

        CLEANUP_ERASE(ctx);

        sha256_init_ctx(&ctx);

        if (extend)
                sha256_process_bytes(digest->buffer, digest->size, &ctx);
        else {
                *digest = (TPM2B_DIGEST) {
                        .size = SHA256_DIGEST_SIZE,
                };
                if (n_data == 0) /* If not extending and no data, return zero hash */
                        return 0;
        }

        FOREACH_ARRAY(d, data, n_data)
                sha256_process_bytes(d->iov_base, d->iov_len, &ctx);

        sha256_finish_ctx(&ctx, digest->buffer);

        return 0;
}

/* Same as tpm2_digest_many() but data is contained in TPM2B_DIGEST[]. The digests may be any size digests. */
int tpm2_digest_many_digests(
                TPMI_ALG_HASH alg,
                TPM2B_DIGEST *digest,
                const TPM2B_DIGEST data[],
                size_t n_data,
                bool extend) {

        _cleanup_free_ struct iovec *iovecs = NULL;

        assert(data || n_data == 0);

        iovecs = new(struct iovec, n_data);
        if (!iovecs)
                return log_oom_debug();

        for (size_t i = 0; i < n_data; i++)
                iovecs[i] = IOVEC_MAKE((void*) data[i].buffer, data[i].size);

        return tpm2_digest_many(alg, digest, iovecs, n_data, extend);
}

/* This hashes the provided pin into a digest value, but also verifies that the final byte is not 0, because
 * the TPM specification Part 1 ("Architecture") section Authorization Values (subsection "Authorization Size
 * Convention") states "Trailing octets of zero are to be removed from any string before it is used as an
 * authValue". Since the TPM doesn't know if the auth value is a "string" or just a hash digest, any hash
 * digest that randomly happens to end in 0 must have the final 0(s) trimmed.
 *
 * This is required at 2 points. First, when setting the authValue during creation of new sealed objects, in
 * tpm2_seal(). This only applies to newly created objects, of course.  Second, when using a previously
 * created sealed object that has an authValue set, we use the sealed objects as the session bind key. This
 * requires calling SetAuth so tpm2-tss can correctly calculate the HMAC to use for the encryption session.
 *
 * TPM implementations will perform the trimming for any authValue for existing sealed objects, so the
 * tpm2-tss library must also perform the trimming before HMAC calculation, but it does not yet; this bug is
 * open to add the trimming: https://github.com/tpm2-software/tpm2-tss/issues/2664
 *
 * Until our minimum tpm2-tss version contains a fix for that bug, we must perform the trimming
 * ourselves. Note that since we are trimming, which is exactly what a TPM implementation would do, this will
 * work for both existing objects with a authValue ending in 0(s) as well as new sealed objects we create,
 * which we will trim the 0(s) from before sending to the TPM.
 */
static void tpm2_trim_auth_value(TPM2B_AUTH *auth) {
        bool trimmed = false;

        assert(auth);

        while (auth->size > 0 && auth->buffer[auth->size - 1] == 0) {
                trimmed = true;
                auth->size--;
        }

        if (trimmed)
                log_debug("authValue ends in 0, trimming as required by the TPM2 specification Part 1 section 'HMAC Computation' authValue Note 2.");
}

int tpm2_auth_value_from_pin(TPMI_ALG_HASH hash, const char *pin, TPM2B_AUTH *ret_auth) {
        TPM2B_AUTH auth = {};
        int r;

        assert(pin);
        assert(ret_auth);

        r = tpm2_digest_buffer(hash, &auth, pin, strlen(pin), /* extend= */ false);
        if (r < 0)
                return r;

        tpm2_trim_auth_value(&auth);

        *ret_auth = TAKE_STRUCT(auth);

        return 0;
}

int tpm2_set_auth_binary(Tpm2Context *c, const Tpm2Handle *handle, const TPM2B_AUTH *auth) {
        TSS2_RC rc;

        assert(c);
        assert(handle);

        if (!auth)
                return 0;

        rc = sym_Esys_TR_SetAuth(c->esys_context, handle->esys_handle, auth);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to load PIN in TPM: %s", sym_Tss2_RC_Decode(rc));

        return 0;
}

int tpm2_set_auth(Tpm2Context *c, const Tpm2Handle *handle, const char *pin) {
        TPM2B_AUTH auth = {};
        int r;

        assert(c);
        assert(handle);

        if (!pin)
                return 0;

        CLEANUP_ERASE(auth);

        r = tpm2_auth_value_from_pin(TPM2_ALG_SHA256, pin, &auth);
        if (r < 0)
                return r;

        return tpm2_set_auth_binary(c, handle, &auth);
}

static bool tpm2_is_encryption_session(Tpm2Context *c, const Tpm2Handle *session) {
        TPMA_SESSION flags = 0;
        TSS2_RC rc;

        assert(c);
        assert(session);

        rc = sym_Esys_TRSess_GetAttributes(c->esys_context, session->esys_handle, &flags);
        if (rc != TSS2_RC_SUCCESS)
                return false;

        return (flags & TPMA_SESSION_DECRYPT) && (flags & TPMA_SESSION_ENCRYPT);
}

int tpm2_make_encryption_session(
                Tpm2Context *c,
                const Tpm2Handle *primary,
                const Tpm2Handle *bind_key,
                Tpm2Handle **ret_session) {

        const TPMA_SESSION sessionAttributes = TPMA_SESSION_DECRYPT | TPMA_SESSION_ENCRYPT |
                        TPMA_SESSION_CONTINUESESSION;
        TSS2_RC rc;
        int r;

        assert(c);
        assert(primary);
        assert(ret_session);

        log_debug("Starting HMAC encryption session.");

        /* Start a salted, unbound HMAC session with a well-known key (e.g. primary key) as tpmKey, which
         * means that the random salt will be encrypted with the well-known key. That way, only the TPM can
         * recover the salt, which is then used for key derivation. */
        _cleanup_(tpm2_handle_freep) Tpm2Handle *session = NULL;
        r = tpm2_handle_new(c, &session);
        if (r < 0)
                return r;

        rc = sym_Esys_StartAuthSession(
                        c->esys_context,
                        primary->esys_handle,
                        bind_key ? bind_key->esys_handle : ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        NULL,
                        TPM2_SE_HMAC,
                        &SESSION_TEMPLATE_SYM_AES_128_CFB,
                        TPM2_ALG_SHA256,
                        &session->esys_handle);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to open session in TPM: %s", sym_Tss2_RC_Decode(rc));

        /* Enable parameter encryption/decryption with AES in CFB mode. Together with HMAC digests (which are
         * always used for sessions), this provides confidentiality, integrity and replay protection for
         * operations that use this session. */
        rc = sym_Esys_TRSess_SetAttributes(c->esys_context, session->esys_handle, sessionAttributes, 0xff);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to configure TPM session: %s", sym_Tss2_RC_Decode(rc));

        *ret_session = TAKE_PTR(session);

        return 0;
}

int tpm2_make_policy_session(
                Tpm2Context *c,
                const Tpm2Handle *primary,
                const Tpm2Handle *encryption_session,
                Tpm2Handle **ret_session) {

        TSS2_RC rc;
        int r;

        assert(c);
        assert(primary);
        assert(encryption_session);
        assert(ret_session);

        if (!tpm2_is_encryption_session(c, encryption_session))
                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "Missing encryption session");

        log_debug("Starting policy session.");

        _cleanup_(tpm2_handle_freep) Tpm2Handle *session = NULL;
        r = tpm2_handle_new(c, &session);
        if (r < 0)
                return r;

        rc = sym_Esys_StartAuthSession(
                        c->esys_context,
                        primary->esys_handle,
                        ESYS_TR_NONE,
                        encryption_session->esys_handle,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        NULL,
                        TPM2_SE_POLICY,
                        &SESSION_TEMPLATE_SYM_AES_128_CFB,
                        TPM2_ALG_SHA256,
                        &session->esys_handle);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to open session in TPM: %s", sym_Tss2_RC_Decode(rc));

        *ret_session = TAKE_PTR(session);

        return 0;
}

static int find_signature(
                JsonVariant *v,
                const TPML_PCR_SELECTION *pcr_selection,
                const void *fp,
                size_t fp_size,
                const void *policy,
                size_t policy_size,
                void *ret_signature,
                size_t *ret_signature_size) {

#if HAVE_OPENSSL
        JsonVariant *b, *i;
        const char *k;
        int r;

        /* Searches for a signature blob in the specified JSON object. Search keys are PCR bank, PCR mask,
         * public key, and policy digest. */

        if (!json_variant_is_object(v))
                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Signature is not a JSON object.");

        uint16_t pcr_bank = pcr_selection->pcrSelections[0].hash;
        uint32_t pcr_mask = tpm2_tpml_pcr_selection_to_mask(pcr_selection, pcr_bank);

        k = tpm2_hash_alg_to_string(pcr_bank);
        if (!k)
                return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Don't know PCR bank %" PRIu16, pcr_bank);

        /* First, find field by bank */
        b = json_variant_by_key(v, k);
        if (!b)
                return log_debug_errno(SYNTHETIC_ERRNO(ENXIO), "Signature lacks data for PCR bank '%s'.", k);

        if (!json_variant_is_array(b))
                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Bank data is not a JSON array.");

        /* Now iterate through all signatures known for this bank */
        JSON_VARIANT_ARRAY_FOREACH(i, b) {
                _cleanup_free_ void *fpj_data = NULL, *polj_data = NULL;
                JsonVariant *maskj, *fpj, *sigj, *polj;
                size_t fpj_size, polj_size;
                uint32_t parsed_mask;

                if (!json_variant_is_object(i))
                        return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Bank data element is not a JSON object");

                /* Check if the PCR mask matches our expectations */
                maskj = json_variant_by_key(i, "pcrs");
                if (!maskj)
                        continue;

                r = tpm2_parse_pcr_json_array(maskj, &parsed_mask);
                if (r < 0)
                        return log_debug_errno(r, "Failed to parse JSON PCR mask");

                if (parsed_mask != pcr_mask)
                        continue; /* Not for this PCR mask */

                /* Then check if this is for the public key we operate with */
                fpj = json_variant_by_key(i, "pkfp");
                if (!fpj)
                        continue;

                r = json_variant_unhex(fpj, &fpj_data, &fpj_size);
                if (r < 0)
                        return log_debug_errno(r, "Failed to decode fingerprint in JSON data: %m");

                if (memcmp_nn(fp, fp_size, fpj_data, fpj_size) != 0)
                        continue; /* Not for this public key */

                /* Finally, check if this is for the PCR policy we expect this to be */
                polj = json_variant_by_key(i, "pol");
                if (!polj)
                        continue;

                r = json_variant_unhex(polj, &polj_data, &polj_size);
                if (r < 0)
                        return log_debug_errno(r, "Failed to decode policy hash JSON data: %m");

                if (memcmp_nn(policy, policy_size, polj_data, polj_size) != 0)
                        continue;

                /* This entry matches all our expectations, now return the signature included in it */
                sigj = json_variant_by_key(i, "sig");
                if (!sigj)
                        continue;

                return json_variant_unbase64(sigj, ret_signature, ret_signature_size);
        }

        return log_debug_errno(SYNTHETIC_ERRNO(ENXIO), "Couldn't find signature for this PCR bank, PCR index and public key.");
#else /* HAVE_OPENSSL */
        return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "OpenSSL support is disabled.");
#endif
}

/* Calculates the "name" of a public key.
 *
 * As specified in TPM2 spec "Part 1: Architecture", a key's "name" is its nameAlg value followed by a hash
 * of its TPM2 public area, all properly marshalled. This allows a key's "name" to be dependent not only on
 * the key fingerprint, but also on the TPM2-specific fields that associated with the key (i.e. all fields in
 * TPMT_PUBLIC). Note that this means an existing key may not change any of its TPMT_PUBLIC fields, since
 * that would also change the key name.
 *
 * Since we (currently) hardcode to always using SHA256 for hashing, this returns an error if the public key
 * nameAlg is not TPM2_ALG_SHA256. */
int tpm2_calculate_pubkey_name(const TPMT_PUBLIC *public, TPM2B_NAME *ret_name) {
        TSS2_RC rc;
        int r;

        assert(public);
        assert(ret_name);

        r = dlopen_tpm2();
        if (r < 0)
                return log_debug_errno(r, "TPM2 support not installed: %m");

        if (public->nameAlg != TPM2_ALG_SHA256)
                return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
                                       "Unsupported nameAlg: 0x%x",
                                       public->nameAlg);

        _cleanup_free_ uint8_t *buf = NULL;
        size_t size = 0;

        buf = (uint8_t*) new(TPMT_PUBLIC, 1);
        if (!buf)
                return log_oom_debug();

        rc = sym_Tss2_MU_TPMT_PUBLIC_Marshal(public, buf, sizeof(TPMT_PUBLIC), &size);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal public key: %s", sym_Tss2_RC_Decode(rc));

        TPM2B_DIGEST digest = {};
        r = tpm2_digest_buffer(TPM2_ALG_SHA256, &digest, buf, size, /* extend= */ false);
        if (r < 0)
                return r;

        TPMT_HA ha = {
                .hashAlg = TPM2_ALG_SHA256,
        };
        assert(digest.size <= sizeof(ha.digest.sha256));
        memcpy_safe(ha.digest.sha256, digest.buffer, digest.size);

        TPM2B_NAME name;
        size = 0;
        rc = sym_Tss2_MU_TPMT_HA_Marshal(&ha, name.name, sizeof(name.name), &size);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal key name: %s", sym_Tss2_RC_Decode(rc));
        name.size = size;

        tpm2_log_debug_name(&name, "Calculated public key name");

        *ret_name = name;

        return 0;
}

/* Get the "name" of a key from the TPM.
 *
 * The "name" of a key is explained above in tpm2_calculate_pubkey_name().
 *
 * The handle must reference a key already present in the TPM. It may be either a public key only, or a
 * public/private keypair. */
int tpm2_get_name(
                Tpm2Context *c,
                const Tpm2Handle *handle,
                TPM2B_NAME **ret_name) {

        _cleanup_(Esys_Freep) TPM2B_NAME *name = NULL;
        TSS2_RC rc;

        assert(c);
        assert(handle);
        assert(ret_name);

        rc = sym_Esys_TR_GetName(c->esys_context, handle->esys_handle, &name);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to get name of public key from TPM: %s", sym_Tss2_RC_Decode(rc));

        tpm2_log_debug_name(name, "Object name");

        *ret_name = TAKE_PTR(name);

        return 0;
}

int tpm2_calculate_nv_index_name(const TPMS_NV_PUBLIC *nvpublic, TPM2B_NAME *ret_name) {
        TSS2_RC rc;
        int r;

        assert(nvpublic);
        assert(ret_name);

        r = dlopen_tpm2();
        if (r < 0)
                return log_debug_errno(r, "TPM2 support not installed: %m");

        if (nvpublic->nameAlg != TPM2_ALG_SHA256)
                return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
                                       "Unsupported nameAlg: 0x%x",
                                       nvpublic->nameAlg);

        _cleanup_free_ uint8_t *buf = NULL;
        size_t size = 0;

        buf = (uint8_t*) new(TPMS_NV_PUBLIC, 1);
        if (!buf)
                return log_oom_debug();

        rc = sym_Tss2_MU_TPMS_NV_PUBLIC_Marshal(nvpublic, buf, sizeof(TPMS_NV_PUBLIC), &size);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal NV index: %s", sym_Tss2_RC_Decode(rc));

        TPM2B_DIGEST digest = {};
        r = tpm2_digest_buffer(TPM2_ALG_SHA256, &digest, buf, size, /* extend= */ false);
        if (r < 0)
                return r;

        TPMT_HA ha = {
                .hashAlg = TPM2_ALG_SHA256,
        };
        assert(digest.size <= sizeof(ha.digest.sha256));
        memcpy_safe(ha.digest.sha256, digest.buffer, digest.size);

        TPM2B_NAME name;
        size = 0;
        rc = sym_Tss2_MU_TPMT_HA_Marshal(&ha, name.name, sizeof(name.name), &size);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal NV index name: %s", sym_Tss2_RC_Decode(rc));
        name.size = size;

        tpm2_log_debug_name(&name, "Calculated NV index name");

        *ret_name = name;

        return 0;
}

/* Extend 'digest' with the PolicyAuthValue calculated hash. */
int tpm2_calculate_policy_auth_value(TPM2B_DIGEST *digest) {
        TPM2_CC command = TPM2_CC_PolicyAuthValue;
        TSS2_RC rc;
        int r;

        assert(digest);
        assert(digest->size == SHA256_DIGEST_SIZE);

        r = dlopen_tpm2();
        if (r < 0)
                return log_debug_errno(r, "TPM2 support not installed: %m");

        uint8_t buf[sizeof(command)];
        size_t offset = 0;

        rc = sym_Tss2_MU_TPM2_CC_Marshal(command, buf, sizeof(buf), &offset);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal PolicyAuthValue command: %s", sym_Tss2_RC_Decode(rc));

        if (offset != sizeof(command))
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Offset 0x%zx wrong after marshalling PolicyAuthValue command", offset);

        r = tpm2_digest_buffer(TPM2_ALG_SHA256, digest, buf, offset, /* extend= */ true);
        if (r < 0)
                return r;

        tpm2_log_debug_digest(digest, "PolicyAuthValue calculated digest");

        return 0;
}

int tpm2_policy_auth_value(
                Tpm2Context *c,
                const Tpm2Handle *session,
                TPM2B_DIGEST **ret_policy_digest) {

        TSS2_RC rc;

        assert(c);
        assert(session);

        log_debug("Submitting AuthValue policy.");

        rc = sym_Esys_PolicyAuthValue(
                        c->esys_context,
                        session->esys_handle,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to add authValue policy to TPM: %s",
                                       sym_Tss2_RC_Decode(rc));

        return tpm2_get_policy_digest(c, session, ret_policy_digest);
}

/* Extend 'digest' with the PolicySigned calculated hash. */
int tpm2_calculate_policy_signed(TPM2B_DIGEST *digest, const TPM2B_NAME *name) {
        TPM2_CC command = TPM2_CC_PolicySigned;
        TSS2_RC rc;
        int r;

        assert(digest);
        assert(digest->size == SHA256_DIGEST_SIZE);
        assert(name);

        r = dlopen_tpm2();
        if (r < 0)
                return log_debug_errno(r, "TPM2 support not installed: %m");

        uint8_t buf[sizeof(command)];
        size_t offset = 0;

        rc = sym_Tss2_MU_TPM2_CC_Marshal(command, buf, sizeof(buf), &offset);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal PolicySigned command: %s", sym_Tss2_RC_Decode(rc));

        if (offset != sizeof(command))
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Offset 0x%zx wrong after marshalling PolicySigned command", offset);

        struct iovec data[] = {
                IOVEC_MAKE(buf, offset),
                IOVEC_MAKE(name->name, name->size),
        };

        r = tpm2_digest_many(TPM2_ALG_SHA256, digest, data, ELEMENTSOF(data), /* extend= */ true);
        if (r < 0)
                return r;

        const TPM2B_NONCE policyRef = {}; /* For now, we do not make use of the policyRef stuff */

        r = tpm2_digest_buffer(TPM2_ALG_SHA256, digest, policyRef.buffer, policyRef.size, /* extend= */ true);
        if (r < 0)
                return r;

        tpm2_log_debug_digest(digest, "PolicySigned calculated digest");

        return 0;
}

int tpm2_policy_signed_hmac_sha256(
                Tpm2Context *c,
                const Tpm2Handle *session,
                const Tpm2Handle *hmac_key_handle,
                const struct iovec *hmac_key,
                TPM2B_DIGEST **ret_policy_digest) {

#if HAVE_OPENSSL
        TSS2_RC rc;
        int r;

        assert(c);
        assert(session);
        assert(hmac_key_handle);
        assert(iovec_is_set(hmac_key));

        /* This sends a TPM2_PolicySigned command to the tpm. As signature key we use an HMAC-SHA256 key
         * specified in the hmac_key parameter. The secret key must be loaded into the TPM already and
         * referenced in hmac_key_handle. */

        log_debug("Submitting PolicySigned policy for HMAC-SHA256.");

        /* Acquire the nonce from the TPM that we shall sign */
        _cleanup_(Esys_Freep) TPM2B_NONCE *nonce = NULL;
        rc = sym_Esys_TRSess_GetNonceTPM(
                        c->esys_context,
                        session->esys_handle,
                        &nonce);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to determine NoneTPM of auth session: %s",
                                       sym_Tss2_RC_Decode(rc));

        be32_t expiration = htobe64(0);
        const TPM2B_DIGEST cpHashA = {};  /* For now, we do not make use of the cpHashA stuff */
        const TPM2B_NONCE policyRef = {}; /* ditto, we do not bother with policyRef */

        /* Put together the data to sign, as per TPM2 Spec Part 3, 23.3.1 */
        struct iovec data_to_sign[] = {
                IOVEC_MAKE(nonce->buffer, nonce->size),
                IOVEC_MAKE(&expiration, sizeof(expiration)),
                IOVEC_MAKE(cpHashA.buffer, cpHashA.size),
                IOVEC_MAKE(policyRef.buffer, policyRef.size),
        };

        /* Now calculate the digest of the data we put together */
        TPM2B_DIGEST digest_to_sign;
        r = tpm2_digest_many(TPM2_ALG_SHA256, &digest_to_sign, data_to_sign, ELEMENTSOF(data_to_sign), /* extend= */ false);
        if (r < 0)
                return r;

        unsigned char hmac_signature[SHA256_DIGEST_SIZE];
        unsigned hmac_signature_size = sizeof(hmac_signature);

        /* And sign this with our key */
        if (!HMAC(EVP_sha256(),
                  hmac_key->iov_base,
                  hmac_key->iov_len,
                  digest_to_sign.buffer,
                  digest_to_sign.size,
                  hmac_signature,
                  &hmac_signature_size))
                return -ENOTRECOVERABLE;

        /* Now bring the signature into a format that the TPM understands */
        TPMT_SIGNATURE sig = {
                .sigAlg = TPM2_ALG_HMAC,
                .signature.hmac.hashAlg = TPM2_ALG_SHA256,
        };
        assert(hmac_signature_size == sizeof(sig.signature.hmac.digest.sha256));
        memcpy(sig.signature.hmac.digest.sha256, hmac_signature, hmac_signature_size);

        /* And submit the whole shebang to the TPM */
        rc = sym_Esys_PolicySigned(
                        c->esys_context,
                        hmac_key_handle->esys_handle,
                        session->esys_handle,
                        /* shandle1= */ ESYS_TR_NONE,
                        /* shandle2= */ ESYS_TR_NONE,
                        /* shandle3= */ ESYS_TR_NONE,
                        nonce,
                        &cpHashA,
                        &policyRef,
                        expiration,
                        &sig,
                        /* timeout= */ NULL,
                        /* policyTicket= */ NULL);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to add PolicySigned policy to TPM: %s",
                                       sym_Tss2_RC_Decode(rc));

        return tpm2_get_policy_digest(c, session, ret_policy_digest);
#else /* HAVE_OPENSSL */
        return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "OpenSSL support is disabled.");
#endif
}

int tpm2_calculate_policy_authorize_nv(
                const TPM2B_NV_PUBLIC *public_info,
                TPM2B_DIGEST *digest) {
        TPM2_CC command = TPM2_CC_PolicyAuthorizeNV;
        TSS2_RC rc;
        int r;

        assert(public_info);
        assert(digest);
        assert(digest->size == SHA256_DIGEST_SIZE);

        r = dlopen_tpm2();
        if (r < 0)
                return log_debug_errno(r, "TPM2 support not installed: %m");

        uint8_t buf[sizeof(command)];
        size_t offset = 0;

        rc = sym_Tss2_MU_TPM2_CC_Marshal(command, buf, sizeof(buf), &offset);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal PolicyAuthorizeNV command: %s", sym_Tss2_RC_Decode(rc));

        if (offset != sizeof(command))
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Offset 0x%zx wrong after marshalling PolicyAuthorizeNV command", offset);

        TPM2B_NV_PUBLIC public_info_copy = *public_info; /* Make a copy, since we must set TPMA_NV_WRITTEN for the calculation */
        public_info_copy.nvPublic.attributes |= TPMA_NV_WRITTEN;

        TPM2B_NAME name = {};
        r = tpm2_calculate_nv_index_name(&public_info_copy.nvPublic, &name);
        if (r < 0)
                return r;

        struct iovec data[] = {
                IOVEC_MAKE(buf, offset),
                IOVEC_MAKE(name.name, name.size),
        };

        r = tpm2_digest_many(TPM2_ALG_SHA256, digest, data, ELEMENTSOF(data), /* extend= */ true);
        if (r < 0)
                return r;

        tpm2_log_debug_digest(digest, "PolicyAuthorizeNV calculated digest");

        return 0;
}

int tpm2_policy_authorize_nv(
                Tpm2Context *c,
                const Tpm2Handle *session,
                const Tpm2Handle *nv_handle,
                TPM2B_DIGEST **ret_policy_digest) {

        TSS2_RC rc;

        assert(c);
        assert(session);

        log_debug("Submitting AuthorizeNV policy.");

        rc = sym_Esys_PolicyAuthorizeNV(
                        c->esys_context,
                        ESYS_TR_RH_OWNER,
                        nv_handle->esys_handle,
                        session->esys_handle,
                        ESYS_TR_PASSWORD,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to add AuthorizeNV policy to TPM: %s",
                                       sym_Tss2_RC_Decode(rc));

        return tpm2_get_policy_digest(c, session, ret_policy_digest);
}

int tpm2_policy_or(
                Tpm2Context *c,
                const Tpm2Handle *session,
                const TPM2B_DIGEST *branches, size_t n_branches,
                TPM2B_DIGEST **ret_policy_digest) {

        TPML_DIGEST hash_list;
        TSS2_RC rc;

        assert(c);
        assert(session);

        if (n_branches > ELEMENTSOF(hash_list.digests))
                return -EOPNOTSUPP;

        log_debug("Submitting OR policy.");

        hash_list = (TPML_DIGEST) {
                .count = n_branches,
        };

        memcpy(hash_list.digests, branches, n_branches * sizeof(TPM2B_DIGEST));

        if (DEBUG_LOGGING)
                for (size_t i = 0; i < hash_list.count; i++) {
                        _cleanup_free_ char *h = hexmem(hash_list.digests[i].buffer, hash_list.digests[i].size);
                        log_debug("Submitting OR Branch #%zu: %s", i, h);
                }

        rc = sym_Esys_PolicyOR(
                        c->esys_context,
                        session->esys_handle,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        &hash_list);
        if (rc != TSS2_RC_SUCCESS)
                return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to add OR policy to TPM: %s",
                                       sym_Tss2_RC_Decode(rc));

        return tpm2_get_policy_digest(c, session, ret_policy_digest);
}

/* Extend 'digest' with the PolicyOR calculated hash. */
int tpm2_calculate_policy_or(const TPM2B_DIGEST *branches, size_t n_branches, TPM2B_DIGEST *digest) {
        TPM2_CC command = TPM2_CC_PolicyOR;
        TSS2_RC rc;
        int r;

        assert(digest);
        assert(digest->size == SHA256_DIGEST_SIZE);

        if (n_branches == 0)
                return -EINVAL;
        if (n_branches == 1)
                log_warning("PolicyOR with a single branch submitted, this is weird.");
        if (n_branches > 8)
                return -E2BIG;

        r = dlopen_tpm2();
        if (r < 0)
                return log_error_errno(r, "TPM2 support not installed: %m");

        uint8_t buf[sizeof(command)];
        size_t offset = 0;

        rc = sym_Tss2_MU_TPM2_CC_Marshal(command, buf, sizeof(buf), &offset);
        if (rc != TSS2_RC_SUCCESS)
                return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal PolicyOR command: %s", sym_Tss2_RC_Decode(rc));

        if (offset != sizeof(command))
                return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Offset 0x%zx wrong after marshalling PolicyOR command", offset);
        _cleanup_free_ struct iovec *data = new(struct iovec, 1 + n_branches);
        if (!data)
                return log_oom();

        data[0] = IOVEC_MAKE(buf, offset);
        for (size_t i = 0; i < n_branches; i++) {
                data[1 + i] = IOVEC_MAKE((void*) branches[i].buffer, branches[i].size);

                if (DEBUG_LOGGING) {
                        _cleanup_free_ char *h = hexmem(branches[i].buffer, branches[i].size);
                        log_debug("OR Branch #%zu: %s", i, h);
                }
        }

        /* PolicyOR does not use the previous hash value; we must zero and then extend it. */
        zero(digest->buffer);

        r = tpm2_digest_many(TPM2_ALG_SHA256, digest, data, 1 + n_branches, /* extend= */ true);
        if (r < 0)
                return r;

        tpm2_log_debug_digest(digest, "PolicyOR calculated digest");

        return 0;
}

/* Extend 'digest' with the PolicyPCR calculated hash. */
int tpm2_calculate_policy_pcr(
                const Tpm2PCRValue *pcr_values,
                size_t n_pcr_values,
                TPM2B_DIGEST *digest) {

        TPM2_CC command = TPM2_CC_PolicyPCR;
        TSS2_RC rc;
        int r;

        assert(pcr_values || n_pcr_values == 0);
        assert(digest);
        assert(digest->size == SHA256_DIGEST_SIZE);

        r = dlopen_tpm2();
        if (r < 0)
                return log_debug_errno(r, "TPM2 support not installed: %m");

        TPML_PCR_SELECTION pcr_selection;
        _cleanup_free_ TPM2B_DIGEST *values = NULL;
        size_t n_values;
        r = tpm2_tpml_pcr_selection_from_pcr_values(pcr_values, n_pcr_values, &pcr_selection, &values, &n_values);
        if (r < 0)
                return log_debug_errno(r, "Could not convert PCR values to TPML_PCR_SELECTION: %m");

        TPM2B_DIGEST hash = {};
        r = tpm2_digest_many_digests(TPM2_ALG_SHA256, &hash, values, n_values, /* extend= */ false);
        if (r < 0)
                return r;

        _cleanup_free_ uint8_t *buf = NULL;
        size_t size = 0, maxsize = sizeof(command) + sizeof(pcr_selection);

        buf = malloc(maxsize);
        if (!buf)
                return log_oom_debug();

        rc = sym_Tss2_MU_TPM2_CC_Marshal(command, buf, maxsize, &size);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal PolicyPCR command: %s", sym_Tss2_RC_Decode(rc));

        rc = sym_Tss2_MU_TPML_PCR_SELECTION_Marshal(&pcr_selection, buf, maxsize, &size);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal PCR selection: %s", sym_Tss2_RC_Decode(rc));

        struct iovec data[] = {
                IOVEC_MAKE(buf, size),
                IOVEC_MAKE(hash.buffer, hash.size),
        };
        r = tpm2_digest_many(TPM2_ALG_SHA256, digest, data, ELEMENTSOF(data), /* extend= */ true);
        if (r < 0)
                return r;

        tpm2_log_debug_digest(digest, "PolicyPCR calculated digest");

        return 0;
}

int tpm2_policy_pcr(
                Tpm2Context *c,
                const Tpm2Handle *session,
                const TPML_PCR_SELECTION *pcr_selection,
                TPM2B_DIGEST **ret_policy_digest) {

        TSS2_RC rc;

        assert(c);
        assert(session);
        assert(pcr_selection);

        log_debug("Submitting PCR hash policy.");

        rc = sym_Esys_PolicyPCR(
                        c->esys_context,
                        session->esys_handle,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        NULL,
                        pcr_selection);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to add PCR policy to TPM: %s", sym_Tss2_RC_Decode(rc));

        return tpm2_get_policy_digest(c, session, ret_policy_digest);
}

/* Extend 'digest' with the PolicyAuthorize calculated hash. */
int tpm2_calculate_policy_authorize(
                const TPM2B_PUBLIC *public,
                const TPM2B_DIGEST *policy_ref,
                TPM2B_DIGEST *digest) {

        TPM2_CC command = TPM2_CC_PolicyAuthorize;
        TSS2_RC rc;
        int r;

        assert(public);
        assert(digest);
        assert(digest->size == SHA256_DIGEST_SIZE);

        r = dlopen_tpm2();
        if (r < 0)
                return log_debug_errno(r, "TPM2 support not installed: %m");

        uint8_t buf[sizeof(command)];
        size_t offset = 0;

        rc = sym_Tss2_MU_TPM2_CC_Marshal(command, buf, sizeof(buf), &offset);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal PolicyAuthorize command: %s", sym_Tss2_RC_Decode(rc));

        if (offset != sizeof(command))
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Offset 0x%zx wrong after marshalling PolicyAuthorize command", offset);

        TPM2B_NAME name = {};
        r = tpm2_calculate_pubkey_name(&public->publicArea, &name);
        if (r < 0)
                return r;

        /* PolicyAuthorize does not use the previous hash value; we must zero and then extend it. */
        zero(digest->buffer);

        struct iovec data[] = {
                IOVEC_MAKE(buf, offset),
                IOVEC_MAKE(name.name, name.size),
        };
        r = tpm2_digest_many(TPM2_ALG_SHA256, digest, data, ELEMENTSOF(data), /* extend= */ true);
        if (r < 0)
                return r;

        /* PolicyAuthorize requires hashing twice; this is either an extension or rehashing. */
        if (policy_ref)
                r = tpm2_digest_many_digests(TPM2_ALG_SHA256, digest, policy_ref, 1, /* extend= */ true);
        else
                r = tpm2_digest_rehash(TPM2_ALG_SHA256, digest);
        if (r < 0)
                return r;

        tpm2_log_debug_digest(digest, "PolicyAuthorize calculated digest");

        return 0;
}

static int tpm2_policy_authorize(
                Tpm2Context *c,
                const Tpm2Handle *session,
                TPML_PCR_SELECTION *pcr_selection,
                const TPM2B_PUBLIC *public,
                const void *fp,
                size_t fp_size,
                JsonVariant *signature_json,
                TPM2B_DIGEST **ret_policy_digest) {

        TSS2_RC rc;
        int r;

        assert(c);
        assert(session);
        assert(pcr_selection);
        assert(public);
        assert(fp && fp_size > 0);

        log_debug("Adding PCR signature policy.");

        _cleanup_(tpm2_handle_freep) Tpm2Handle *pubkey_handle = NULL;
        r = tpm2_load_external(c, NULL, public, NULL, &pubkey_handle);
        if (r < 0)
                return r;

        /* Acquire the "name" of what we just loaded */
        _cleanup_(Esys_Freep) TPM2B_NAME *pubkey_name = NULL;
        r = tpm2_get_name(c, pubkey_handle, &pubkey_name);
        if (r < 0)
                return r;

        /* If we have a signature, proceed with verifying the PCR digest */
        const TPMT_TK_VERIFIED *check_ticket;
        _cleanup_(Esys_Freep) TPMT_TK_VERIFIED *check_ticket_buffer = NULL;
        _cleanup_(Esys_Freep) TPM2B_DIGEST *approved_policy = NULL;
        if (signature_json) {
                r = tpm2_policy_pcr(
                                c,
                                session,
                                pcr_selection,
                                &approved_policy);
                if (r < 0)
                        return r;

                _cleanup_free_ void *signature_raw = NULL;
                size_t signature_size;

                r = find_signature(
                                signature_json,
                                pcr_selection,
                                fp, fp_size,
                                approved_policy->buffer,
                                approved_policy->size,
                                &signature_raw,
                                &signature_size);
                if (r < 0)
                        return r;

                /* TPM2_VerifySignature() will only verify the RSA part of the RSA+SHA256 signature,
                 * hence we need to do the SHA256 part ourselves, first */
                TPM2B_DIGEST signature_hash = *approved_policy;
                r = tpm2_digest_rehash(TPM2_ALG_SHA256, &signature_hash);
                if (r < 0)
                        return r;

                r = TPM2B_PUBLIC_KEY_RSA_CHECK_SIZE(signature_size);
                if (r < 0)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Signature larger than buffer.");

                TPMT_SIGNATURE policy_signature = {
                        .sigAlg = TPM2_ALG_RSASSA,
                        .signature.rsassa = {
                                .hash = TPM2_ALG_SHA256,
                                .sig = TPM2B_PUBLIC_KEY_RSA_MAKE(signature_raw, signature_size),
                        },
                };

                rc = sym_Esys_VerifySignature(
                                c->esys_context,
                                pubkey_handle->esys_handle,
                                ESYS_TR_NONE,
                                ESYS_TR_NONE,
                                ESYS_TR_NONE,
                                &signature_hash,
                                &policy_signature,
                                &check_ticket_buffer);
                if (rc != TSS2_RC_SUCCESS)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                               "Failed to validate signature in TPM: %s", sym_Tss2_RC_Decode(rc));

                check_ticket = check_ticket_buffer;
        } else {
                /* When enrolling, we pass a NULL ticket */
                static const TPMT_TK_VERIFIED check_ticket_null = {
                        .tag = TPM2_ST_VERIFIED,
                        .hierarchy = TPM2_RH_OWNER,
                };

                check_ticket = &check_ticket_null;
        }

        rc = sym_Esys_PolicyAuthorize(
                        c->esys_context,
                        session->esys_handle,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        approved_policy,
                        /* policyRef= */ &(const TPM2B_NONCE) {},
                        pubkey_name,
                        check_ticket);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to push Authorize policy into TPM: %s", sym_Tss2_RC_Decode(rc));

        return tpm2_get_policy_digest(c, session, ret_policy_digest);
}

/* Extend 'digest' with the calculated policy hash. */
int tpm2_calculate_sealing_policy(
                const Tpm2PCRValue *pcr_values,
                size_t n_pcr_values,
                const TPM2B_PUBLIC *public,
                bool use_pin,
                const Tpm2PCRLockPolicy *pcrlock_policy,
                TPM2B_DIGEST *digest) {

        int r;

        assert(pcr_values || n_pcr_values == 0);
        assert(digest);

        if (public && pcrlock_policy)
                return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Policies with both signed PCR and pcrlock are currently not supported.");

        if (public) {
                r = tpm2_calculate_policy_authorize(public, NULL, digest);
                if (r < 0)
                        return r;
        }

        if (pcrlock_policy) {
                TPM2B_NV_PUBLIC nv_public;

                r = tpm2_unmarshal_nv_public(
                                pcrlock_policy->nv_public.iov_base,
                                pcrlock_policy->nv_public.iov_len,
                                &nv_public);
                if (r < 0)
                        return r;

                r = tpm2_calculate_policy_authorize_nv(&nv_public, digest);
                if (r < 0)
                        return r;
        }

        if (n_pcr_values > 0) {
                r = tpm2_calculate_policy_pcr(pcr_values, n_pcr_values, digest);
                if (r < 0)
                        return r;
        }

        if (use_pin) {
                r = tpm2_calculate_policy_auth_value(digest);
                if (r < 0)
                        return r;
        }

        return 0;
}

static int tpm2_build_sealing_policy(
                Tpm2Context *c,
                const Tpm2Handle *session,
                uint32_t hash_pcr_mask,
                uint16_t pcr_bank,
                const TPM2B_PUBLIC *public,
                const void *fp,
                size_t fp_size,
                uint32_t pubkey_pcr_mask,
                JsonVariant *signature_json,
                bool use_pin,
                const Tpm2PCRLockPolicy *pcrlock_policy,
                TPM2B_DIGEST **ret_policy_digest) {

        int r;

        assert(c);
        assert(session);
        assert(pubkey_pcr_mask == 0 || public);

        log_debug("Building sealing policy.");

        if ((hash_pcr_mask | pubkey_pcr_mask) != 0) {
                r = tpm2_pcr_mask_good(c, pcr_bank, hash_pcr_mask|pubkey_pcr_mask);
                if (r < 0)
                        return r;
                if (r == 0)
                        log_debug("Selected TPM2 PCRs are not initialized on this system.");
        }

        if (pubkey_pcr_mask != 0 && pcrlock_policy)
                return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Policies with both signed PCR and pcrlock are currently not supported.");

        if (pubkey_pcr_mask != 0) {
                TPML_PCR_SELECTION pcr_selection;
                tpm2_tpml_pcr_selection_from_mask(pubkey_pcr_mask, (TPMI_ALG_HASH)pcr_bank, &pcr_selection);
                r = tpm2_policy_authorize(c, session, &pcr_selection, public, fp, fp_size, signature_json, NULL);
                if (r < 0)
                        return r;
        }

        if (pcrlock_policy) {
                _cleanup_(tpm2_handle_freep) Tpm2Handle *nv_handle = NULL;

                r = tpm2_policy_super_pcr(
                                c,
                                session,
                                &pcrlock_policy->prediction,
                                pcrlock_policy->algorithm);
                if (r < 0)
                        return r;

                r = tpm2_deserialize(
                                c,
                                pcrlock_policy->nv_handle.iov_base,
                                pcrlock_policy->nv_handle.iov_len,
                                &nv_handle);
                if (r < 0)
                        return r;

                r = tpm2_policy_authorize_nv(
                                c,
                                session,
                                nv_handle,
                                NULL);
                if (r < 0)
                        return r;
        }

        if (hash_pcr_mask != 0) {
                TPML_PCR_SELECTION pcr_selection;
                tpm2_tpml_pcr_selection_from_mask(hash_pcr_mask, (TPMI_ALG_HASH)pcr_bank, &pcr_selection);
                r = tpm2_policy_pcr(c, session, &pcr_selection, NULL);
                if (r < 0)
                        return r;
        }

        if (use_pin) {
                r = tpm2_policy_auth_value(c, session, NULL);
                if (r < 0)
                        return r;
        }

        r = tpm2_get_policy_digest(c, session, ret_policy_digest);
        if (r < 0)
                return r;

        return 0;
}

#if HAVE_OPENSSL
static const struct {
        TPM2_ECC_CURVE tpm2_ecc_curve_id;
        int openssl_ecc_curve_id;
} tpm2_openssl_ecc_curve_table[] = {
        { TPM2_ECC_NIST_P192, NID_X9_62_prime192v1, },
        { TPM2_ECC_NIST_P224, NID_secp224r1,        },
        { TPM2_ECC_NIST_P256, NID_X9_62_prime256v1, },
        { TPM2_ECC_NIST_P384, NID_secp384r1,        },
        { TPM2_ECC_NIST_P521, NID_secp521r1,        },
        { TPM2_ECC_SM2_P256,  NID_sm2,              },
};

static int tpm2_ecc_curve_from_openssl_curve_id(int openssl_ecc_curve_id, TPM2_ECC_CURVE *ret) {
        assert(ret);

        FOREACH_ELEMENT(t, tpm2_openssl_ecc_curve_table)
                if (t->openssl_ecc_curve_id == openssl_ecc_curve_id) {
                        *ret = t->tpm2_ecc_curve_id;
                        return 0;
                }

        return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
                               "OpenSSL ECC curve id %d not supported.", openssl_ecc_curve_id);
}

static int tpm2_ecc_curve_to_openssl_curve_id(TPM2_ECC_CURVE tpm2_ecc_curve_id, int *ret) {
        assert(ret);

        FOREACH_ELEMENT(t, tpm2_openssl_ecc_curve_table)
                if (t->tpm2_ecc_curve_id == tpm2_ecc_curve_id) {
                        *ret = t->openssl_ecc_curve_id;
                        return 0;
                }

        return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
                               "TPM2 ECC curve %u not supported.", tpm2_ecc_curve_id);
}

#define TPM2_RSA_DEFAULT_EXPONENT UINT32_C(0x10001)

int tpm2_tpm2b_public_to_openssl_pkey(const TPM2B_PUBLIC *public, EVP_PKEY **ret) {
        int r;

        assert(public);
        assert(ret);

        const TPMT_PUBLIC *p = &public->publicArea;
        switch (p->type) {
        case TPM2_ALG_ECC: {
                int curve_id;
                r = tpm2_ecc_curve_to_openssl_curve_id(p->parameters.eccDetail.curveID, &curve_id);
                if (r < 0)
                        return r;

                const TPMS_ECC_POINT *point = &p->unique.ecc;
                return ecc_pkey_from_curve_x_y(
                                curve_id,
                                point->x.buffer,
                                point->x.size,
                                point->y.buffer,
                                point->y.size,
                                ret);
        }
        case TPM2_ALG_RSA: {
                /* TPM specification Part 2 ("Structures") section for TPMS_RSA_PARAMS states "An exponent of
                 * zero indicates that the exponent is the default of 2^16 + 1". */
                uint32_t exponent = htobe32(p->parameters.rsaDetail.exponent ?: TPM2_RSA_DEFAULT_EXPONENT);
                return rsa_pkey_from_n_e(
                                p->unique.rsa.buffer,
                                p->unique.rsa.size,
                                &exponent,
                                sizeof(exponent),
                                ret);
        }
        default:
                return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
                                       "TPM2 asymmetric algorithm 0x%" PRIx16 " not supported.", p->type);
        }
}

/* Be careful before changing anything in this function, as the TPM key "name" is calculated using the entire
 * TPMT_PUBLIC (after marshalling), and that "name" is used (for example) to calculate the policy hash for
 * the Authorize policy. So we must ensure this conversion of a PEM to TPM2B_PUBLIC does not change the
 * "name", because it would break unsealing of previously-sealed objects that used (for example)
 * tpm2_calculate_policy_authorize(). See bug #30546. */
int tpm2_tpm2b_public_from_openssl_pkey(const EVP_PKEY *pkey, TPM2B_PUBLIC *ret) {
        int key_id, r;

        assert(pkey);
        assert(ret);

        TPMT_PUBLIC public = {
                .nameAlg = TPM2_ALG_SHA256,
                .objectAttributes = TPMA_OBJECT_DECRYPT | TPMA_OBJECT_SIGN_ENCRYPT | TPMA_OBJECT_USERWITHAUTH,
                .parameters.asymDetail = {
                        .symmetric.algorithm = TPM2_ALG_NULL,
                        .scheme.scheme = TPM2_ALG_NULL,
                },
        };

#if OPENSSL_VERSION_MAJOR >= 3
        key_id = EVP_PKEY_get_id(pkey);
#else
        key_id = EVP_PKEY_id(pkey);
#endif

        switch (key_id) {
        case EVP_PKEY_EC: {
                public.type = TPM2_ALG_ECC;

                int curve_id;
                _cleanup_free_ void *x = NULL, *y = NULL;
                size_t x_size, y_size;
                r = ecc_pkey_to_curve_x_y(pkey, &curve_id, &x, &x_size, &y, &y_size);
                if (r < 0)
                        return log_debug_errno(r, "Could not get ECC key curve/x/y: %m");

                TPM2_ECC_CURVE curve;
                r = tpm2_ecc_curve_from_openssl_curve_id(curve_id, &curve);
                if (r < 0)
                        return r;

                public.parameters.eccDetail.curveID = curve;

                public.parameters.eccDetail.kdf.scheme = TPM2_ALG_NULL;

                r = TPM2B_ECC_PARAMETER_CHECK_SIZE(x_size);
                if (r < 0)
                        return log_debug_errno(r, "ECC key x size %zu too large.", x_size);

                public.unique.ecc.x = TPM2B_ECC_PARAMETER_MAKE(x, x_size);

                r = TPM2B_ECC_PARAMETER_CHECK_SIZE(y_size);
                if (r < 0)
                        return log_debug_errno(r, "ECC key y size %zu too large.", y_size);

                public.unique.ecc.y = TPM2B_ECC_PARAMETER_MAKE(y, y_size);

                break;
        }
        case EVP_PKEY_RSA: {
                public.type = TPM2_ALG_RSA;

                _cleanup_free_ void *n = NULL, *e = NULL;
                size_t n_size, e_size;
                r = rsa_pkey_to_n_e(pkey, &n, &n_size, &e, &e_size);
                if (r < 0)
                        return log_debug_errno(r, "Could not get RSA key n/e: %m");

                r = TPM2B_PUBLIC_KEY_RSA_CHECK_SIZE(n_size);
                if (r < 0)
                        return log_debug_errno(r, "RSA key n size %zu too large.", n_size);

                public.unique.rsa = TPM2B_PUBLIC_KEY_RSA_MAKE(n, n_size);
                public.parameters.rsaDetail.keyBits = n_size * 8;

                if (sizeof(uint32_t) < e_size)
                        return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
                                               "RSA key e size %zu too large.", e_size);

                uint32_t exponent = 0;
                memcpy(&exponent, e, e_size);
                exponent = be32toh(exponent) >> (32 - e_size * 8);

                /* TPM specification Part 2 ("Structures") section for TPMS_RSA_PARAMS states "An exponent of
                 * zero indicates that the exponent is the default of 2^16 + 1". However, we have no reason
                 * to special case it in our PEM->TPM2B_PUBLIC conversion, and doing so could break backwards
                 * compatibility, so even if it is the "default" value of 0x10001, we do not set it to 0. */
                public.parameters.rsaDetail.exponent = exponent;

                break;
        }
        default:
                return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
                                       "EVP_PKEY type %d not supported.", key_id);
        }

        *ret = (TPM2B_PUBLIC) {
                .size = sizeof(public),
                .publicArea = public,
        };

        return 0;
}
#endif

int tpm2_tpm2b_public_to_fingerprint(
                const TPM2B_PUBLIC *public,
                void **ret_fingerprint,
                size_t *ret_fingerprint_size) {

#if HAVE_OPENSSL
        int r;

        assert(public);
        assert(ret_fingerprint);
        assert(ret_fingerprint_size);

        _cleanup_(EVP_PKEY_freep) EVP_PKEY *pkey = NULL;
        r = tpm2_tpm2b_public_to_openssl_pkey(public, &pkey);
        if (r < 0)
                return r;

        /* Hardcode fingerprint to SHA256 */
        return pubkey_fingerprint(pkey, EVP_sha256(), ret_fingerprint, ret_fingerprint_size);
#else
        return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "OpenSSL support is disabled.");
#endif
}

int tpm2_tpm2b_public_from_pem(const void *pem, size_t pem_size, TPM2B_PUBLIC *ret) {
#if HAVE_OPENSSL
        int r;

        assert(pem);
        assert(ret);

        _cleanup_(EVP_PKEY_freep) EVP_PKEY *pkey = NULL;
        r = openssl_pkey_from_pem(pem, pem_size, &pkey);
        if (r < 0)
                return r;

        return tpm2_tpm2b_public_from_openssl_pkey(pkey, ret);
#else
        return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "OpenSSL support is disabled.");
#endif
}

/* Marshal the public, private, and seed objects into a single nonstandard 'blob'. The public and private
 * objects are required, while the seed is optional. This is not a (publicly) standard format, this is
 * specific to how we currently store the sealed object. This 'blob' can be unmarshalled by
 * tpm2_unmarshal_blob(). */
int tpm2_marshal_blob(
                const TPM2B_PUBLIC *public,
                const TPM2B_PRIVATE *private,
                const TPM2B_ENCRYPTED_SECRET *seed,
                void **ret_blob,
                size_t *ret_blob_size) {

        TSS2_RC rc;

        assert(public);
        assert(private);
        assert(ret_blob);
        assert(ret_blob_size);

        size_t max_size = sizeof(*private) + sizeof(*public);
        if (seed)
                max_size += sizeof(*seed);

        _cleanup_free_ void *blob = malloc(max_size);
        if (!blob)
                return log_oom_debug();

        size_t blob_size = 0;
        rc = sym_Tss2_MU_TPM2B_PRIVATE_Marshal(private, blob, max_size, &blob_size);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal private key: %s", sym_Tss2_RC_Decode(rc));

        rc = sym_Tss2_MU_TPM2B_PUBLIC_Marshal(public, blob, max_size, &blob_size);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal public key: %s", sym_Tss2_RC_Decode(rc));

        if (seed) {
                rc = sym_Tss2_MU_TPM2B_ENCRYPTED_SECRET_Marshal(seed, blob, max_size, &blob_size);
                if (rc != TSS2_RC_SUCCESS)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                               "Failed to marshal encrypted seed: %s", sym_Tss2_RC_Decode(rc));
        }

        *ret_blob = TAKE_PTR(blob);
        *ret_blob_size = blob_size;

        return 0;
}

/* Unmarshal the 'blob' into public, private, and seed objects. The public and private objects are required
 * in the 'blob', while the seed is optional. This is not a (publicly) standard format, this is specific to
 * how we currently store the sealed object. This expects the 'blob' to have been created by
 * tpm2_marshal_blob(). */
int tpm2_unmarshal_blob(
                const void *blob,
                size_t blob_size,
                TPM2B_PUBLIC *ret_public,
                TPM2B_PRIVATE *ret_private,
                TPM2B_ENCRYPTED_SECRET *ret_seed) {

        TSS2_RC rc;

        assert(blob);
        assert(ret_public);
        assert(ret_private);
        assert(ret_seed);

        TPM2B_PRIVATE private = {};
        size_t offset = 0;
        rc = sym_Tss2_MU_TPM2B_PRIVATE_Unmarshal(blob, blob_size, &offset, &private);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to unmarshal private key: %s", sym_Tss2_RC_Decode(rc));

        TPM2B_PUBLIC public = {};
        rc = sym_Tss2_MU_TPM2B_PUBLIC_Unmarshal(blob, blob_size, &offset, &public);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to unmarshal public key: %s", sym_Tss2_RC_Decode(rc));

        TPM2B_ENCRYPTED_SECRET seed = {};
        if (blob_size > offset) {
                rc = sym_Tss2_MU_TPM2B_ENCRYPTED_SECRET_Unmarshal(blob, blob_size, &offset, &seed);
                if (rc != TSS2_RC_SUCCESS)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                               "Failed to unmarshal encrypted seed: %s", sym_Tss2_RC_Decode(rc));
        }

        *ret_public = public;
        *ret_private = private;
        *ret_seed = seed;

        return 0;
}

/* Calculate a serialized handle. Once the upstream tpm2-tss library provides an api to do this, we can
 * remove this function. The addition of this functionality in tpm2-tss may be tracked here:
 * https://github.com/tpm2-software/tpm2-tss/issues/2575 */
int tpm2_calculate_serialize(
                TPM2_HANDLE handle,
                const TPM2B_NAME *name,
                const TPM2B_PUBLIC *public,
                void **ret_serialized,
                size_t *ret_serialized_size) {

        TSS2_RC rc;

        assert(name);
        assert(public);
        assert(ret_serialized);
        assert(ret_serialized_size);

        size_t max_size = sizeof(TPM2_HANDLE) + sizeof(TPM2B_NAME) + sizeof(uint32_t) + sizeof(TPM2B_PUBLIC);
        _cleanup_free_ void *serialized = malloc(max_size);
        if (!serialized)
                return log_oom_debug();

        size_t serialized_size = 0;
        rc = sym_Tss2_MU_TPM2_HANDLE_Marshal(handle, serialized, max_size, &serialized_size);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal tpm handle: %s", sym_Tss2_RC_Decode(rc));

        rc = sym_Tss2_MU_TPM2B_NAME_Marshal(name, serialized, max_size, &serialized_size);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal name: %s", sym_Tss2_RC_Decode(rc));

        /* This is defined (non-publicly) in the tpm2-tss source as IESYSC_KEY_RSRC, to a value of "1". */
        rc = sym_Tss2_MU_UINT32_Marshal(UINT32_C(1), serialized, max_size, &serialized_size);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal esys resource id: %s", sym_Tss2_RC_Decode(rc));

        rc = sym_Tss2_MU_TPM2B_PUBLIC_Marshal(public, serialized, max_size, &serialized_size);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal public: %s", sym_Tss2_RC_Decode(rc));

        *ret_serialized = TAKE_PTR(serialized);
        *ret_serialized_size = serialized_size;

        return 0;
}

/* Serialize a handle. This produces a binary object that can be later deserialized (by the same TPM), even
 * across restarts of the TPM or reboots (assuming the handle is persistent). */
int tpm2_serialize(
                Tpm2Context *c,
                const Tpm2Handle *handle,
                void **ret_serialized,
                size_t *ret_serialized_size) {

        TSS2_RC rc;

        assert(c);
        assert(handle);
        assert(ret_serialized);
        assert(ret_serialized_size);

        _cleanup_(Esys_Freep) unsigned char *serialized = NULL;
        size_t size = 0;
        rc = sym_Esys_TR_Serialize(c->esys_context, handle->esys_handle, &serialized, &size);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to serialize: %s", sym_Tss2_RC_Decode(rc));

        *ret_serialized = TAKE_PTR(serialized);
        *ret_serialized_size = size;

        return 0;
}

int tpm2_deserialize(
                Tpm2Context *c,
                const void *serialized,
                size_t serialized_size,
                Tpm2Handle **ret_handle) {

        TSS2_RC rc;
        int r;

        assert(c);
        assert(serialized);
        assert(ret_handle);

        _cleanup_(tpm2_handle_freep) Tpm2Handle *handle = NULL;
        r = tpm2_handle_new(c, &handle);
        if (r < 0)
                return r;

        /* Since this is an existing handle in the TPM we should not implicitly flush it. */
        handle->flush = false;

        rc = sym_Esys_TR_Deserialize(c->esys_context, serialized, serialized_size, &handle->esys_handle);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to deserialize: %s", sym_Tss2_RC_Decode(rc));

        *ret_handle = TAKE_PTR(handle);

        return 0;
}

#if HAVE_OPENSSL

/* KDFa() as defined by the TPM spec. */
static int tpm2_kdfa(
              TPMI_ALG_HASH hash_alg,
              const void *key,
              size_t key_len,
              const char *label,
              const void *context,
              size_t context_len,
              size_t bits,
              void **ret_key,
              size_t *ret_key_len) {

        int r;

        assert(key);
        assert(label);
        assert(context || context_len == 0);
        assert(bits > 0);
        assert(bits <= SIZE_MAX - 7);
        assert(ret_key);
        assert(ret_key_len);

        log_debug("Calculating KDFa().");

        size_t len = DIV_ROUND_UP(bits, 8);

        const char *hash_alg_name = tpm2_hash_alg_to_string(hash_alg);
        if (!hash_alg_name)
                return -EOPNOTSUPP;

        _cleanup_free_ void *buf = NULL;
        r = kdf_kb_hmac_derive(
                        "COUNTER",
                        hash_alg_name,
                        key,
                        key_len,
                        label,
                        strlen(label),
                        context,
                        context_len,
                        /* seed= */ NULL,
                        /* seed_len= */ 0,
                        len,
                        &buf);
        if (r < 0)
                return r;

        /* If the number of bits results in a partial byte, the TPM spec requires we zero the unrequested
         * bits in the MSB (i.e. at index 0). From the spec Part 1 ("Architecture") section on Key
         * Derivation Function, specifically KDFa():
         *
         * "The implied return from this function is a sequence of octets with a length equal to (bits + 7) /
         * 8. If bits is not an even multiple of 8, then the returned value occupies the least significant
         * bits of the returned octet array, and the additional, high-order bits in the 0th octet are
         * CLEAR. The unused bits of the most significant octet (MSO) are masked off and not shifted." */
        size_t partial = bits % 8;
        if (partial > 0)
                ((uint8_t*) buf)[0] &= 0xffu >> (8 - partial);

        *ret_key = TAKE_PTR(buf);
        *ret_key_len = len;

        return 0;
}

/* KDFe() as defined by the TPM spec. */
static int tpm2_kdfe(
              TPMI_ALG_HASH hash_alg,
              const void *shared_secret,
              size_t shared_secret_len,
              const char *label,
              const void *context_u,
              size_t context_u_size,
              const void *context_v,
              size_t context_v_size,
              size_t bits,
              void **ret_key,
              size_t *ret_key_len) {

        int r;

        assert(shared_secret);
        assert(label);
        assert(context_u);
        assert(context_v);
        assert(bits > 0);
        assert(bits <= SIZE_MAX - 7);
        assert(ret_key);
        assert(ret_key_len);

        log_debug("Calculating KDFe().");

        size_t len = DIV_ROUND_UP(bits, 8);

        const char *hash_alg_name = tpm2_hash_alg_to_string(hash_alg);
        if (!hash_alg_name)
                return -EOPNOTSUPP;

        size_t info_len = strlen(label) + 1 + context_u_size + context_v_size;
        _cleanup_free_ void *info = malloc(info_len);
        if (!info)
                return log_oom_debug();

        void *end = mempcpy(mempcpy(stpcpy(info, label) + 1, context_u, context_u_size), context_v, context_v_size);
        /* assert we copied exactly the right amount that we allocated */
        assert(end > info && (uintptr_t) end - (uintptr_t) info == info_len);

        _cleanup_free_ void *buf = NULL;
        r = kdf_ss_derive(
                        hash_alg_name,
                        shared_secret,
                        shared_secret_len,
                        /* salt= */ NULL,
                        /* salt_size= */ 0,
                        info,
                        info_len,
                        len,
                        &buf);
        if (r < 0)
                return r;

        *ret_key = TAKE_PTR(buf);
        *ret_key_len = len;

        return 0;
}

static int tpm2_calculate_seal_public(
                const TPM2B_PUBLIC *parent,
                const TPMA_OBJECT *attributes,
                const TPM2B_DIGEST *policy,
                const TPM2B_DIGEST *seed,
                const void *secret,
                size_t secret_size,
                TPM2B_PUBLIC *ret) {

        int r;

        assert(parent);
        assert(seed);
        assert(secret);
        assert(ret);

        log_debug("Calculating public part of sealed object.");

        struct iovec data[] = {
                IOVEC_MAKE((void*) seed->buffer, seed->size),
                IOVEC_MAKE((void*) secret, secret_size),
        };
        TPM2B_DIGEST unique;
        r = tpm2_digest_many(
                        parent->publicArea.nameAlg,
                        &unique,
                        data,
                        ELEMENTSOF(data),
                        /* extend= */ false);
        if (r < 0)
                return r;

        *ret = (TPM2B_PUBLIC) {
                .size = sizeof(TPMT_PUBLIC),
                .publicArea = {
                        .type = TPM2_ALG_KEYEDHASH,
                        .nameAlg = parent->publicArea.nameAlg,
                        .objectAttributes = attributes ? *attributes : 0,
                        .authPolicy = policy ? *policy : TPM2B_DIGEST_MAKE(NULL, unique.size),
                        .parameters.keyedHashDetail.scheme.scheme = TPM2_ALG_NULL,
                        .unique.keyedHash = unique,
                },
        };

        return 0;
}

static int tpm2_calculate_seal_private(
                const TPM2B_PUBLIC *parent,
                const TPM2B_NAME *name,
                const char *pin,
                const TPM2B_DIGEST *seed,
                const void *secret,
                size_t secret_size,
                TPM2B_PRIVATE *ret) {

        TSS2_RC rc;
        int r;

        assert(parent);
        assert(name);
        assert(seed);
        assert(secret);
        assert(ret);

        log_debug("Calculating private part of sealed object.");

        _cleanup_free_ void *storage_key = NULL;
        size_t storage_key_size;
        r = tpm2_kdfa(parent->publicArea.nameAlg,
                      seed->buffer,
                      seed->size,
                      "STORAGE",
                      name->name,
                      name->size,
                      (size_t) parent->publicArea.parameters.asymDetail.symmetric.keyBits.sym,
                      &storage_key,
                      &storage_key_size);
        if (r < 0)
                return log_debug_errno(r, "Could not calculate storage key KDFa: %m");

        r = tpm2_hash_alg_to_size(parent->publicArea.nameAlg);
        if (r < 0)
                return -EOPNOTSUPP;

        size_t bits = (size_t) r * 8;

        _cleanup_free_ void *integrity_key = NULL;
        size_t integrity_key_size;
        r = tpm2_kdfa(parent->publicArea.nameAlg,
                      seed->buffer,
                      seed->size,
                      "INTEGRITY",
                      /* context= */ NULL,
                      /* n_context= */ 0,
                      bits,
                      &integrity_key,
                      &integrity_key_size);
        if (r < 0)
                return log_debug_errno(r, "Could not calculate integrity key KDFa: %m");

        TPM2B_AUTH auth = {};
        if (pin) {
                r = tpm2_auth_value_from_pin(parent->publicArea.nameAlg, pin, &auth);
                if (r < 0)
                        return r;
        }

        TPM2B_SENSITIVE sensitive = {
                .size = sizeof(TPMT_SENSITIVE),
                .sensitiveArea = {
                        .sensitiveType = TPM2_ALG_KEYEDHASH,
                        .authValue = auth,
                        .seedValue = *seed,
                        .sensitive.bits = TPM2B_SENSITIVE_DATA_MAKE(secret, secret_size),
                },
        };

        _cleanup_free_ void *marshalled_sensitive = malloc(sizeof(sensitive));
        if (!marshalled_sensitive)
                return log_oom_debug();

        size_t marshalled_sensitive_size = 0;
        rc = sym_Tss2_MU_TPM2B_SENSITIVE_Marshal(
                        &sensitive,
                        marshalled_sensitive,
                        sizeof(sensitive),
                        &marshalled_sensitive_size);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal sensitive: %s", sym_Tss2_RC_Decode(rc));

        const char *sym_alg = tpm2_sym_alg_to_string(parent->publicArea.parameters.asymDetail.symmetric.algorithm);
        if (!sym_alg)
                return -EOPNOTSUPP;

        const char *sym_mode = tpm2_sym_mode_to_string(parent->publicArea.parameters.asymDetail.symmetric.mode.sym);
        if (!sym_mode)
                return -EOPNOTSUPP;

        _cleanup_free_ void *encrypted_sensitive = NULL;
        size_t encrypted_sensitive_size;
        r = openssl_cipher(
                        sym_alg,
                        parent->publicArea.parameters.asymDetail.symmetric.keyBits.sym,
                        sym_mode,
                        storage_key, storage_key_size,
                        /* iv= */ NULL, /* n_iv= */ 0,
                        marshalled_sensitive, marshalled_sensitive_size,
                        &encrypted_sensitive, &encrypted_sensitive_size);
        if (r < 0)
                return r;

        const char *hash_alg_name = tpm2_hash_alg_to_string(parent->publicArea.nameAlg);
        if (!hash_alg_name)
                return -EOPNOTSUPP;

        _cleanup_free_ void *hmac_buffer = NULL;
        size_t hmac_size = 0;
        struct iovec hmac_data[] = {
                IOVEC_MAKE((void*) encrypted_sensitive, encrypted_sensitive_size),
                IOVEC_MAKE((void*) name->name, name->size),
        };
        r = openssl_hmac_many(
                        hash_alg_name,
                        integrity_key,
                        integrity_key_size,
                        hmac_data,
                        ELEMENTSOF(hmac_data),
                        &hmac_buffer,
                        &hmac_size);
        if (r < 0)
                return r;

        TPM2B_DIGEST outer_hmac = TPM2B_DIGEST_MAKE(hmac_buffer, hmac_size);

        TPM2B_PRIVATE private = {};
        size_t private_size = 0;
        rc = sym_Tss2_MU_TPM2B_DIGEST_Marshal(
                        &outer_hmac,
                        private.buffer,
                        sizeof(private.buffer),
                        &private_size);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal digest: %s", sym_Tss2_RC_Decode(rc));
        private.size = private_size;

        assert(sizeof(private.buffer) - private.size >= encrypted_sensitive_size);
        memcpy_safe(&private.buffer[private.size], encrypted_sensitive, encrypted_sensitive_size);
        private.size += encrypted_sensitive_size;

        *ret = private;

        return 0;
}

static int tpm2_calculate_seal_rsa_seed(
                const TPM2B_PUBLIC *parent,
                void **ret_seed,
                size_t *ret_seed_size,
                void **ret_encrypted_seed,
                size_t *ret_encrypted_seed_size) {

        int r;

        assert(parent);
        assert(ret_seed);
        assert(ret_seed_size);
        assert(ret_encrypted_seed);
        assert(ret_encrypted_seed_size);

        log_debug("Calculating encrypted seed for RSA sealed object.");

        _cleanup_(EVP_PKEY_freep) EVP_PKEY *parent_pkey = NULL;
        r = tpm2_tpm2b_public_to_openssl_pkey(parent, &parent_pkey);
        if (r < 0)
                return log_debug_errno(r, "Could not convert TPM2B_PUBLIC to OpenSSL PKEY: %m");

        r = tpm2_hash_alg_to_size(parent->publicArea.nameAlg);
        if (r < 0)
                return -EOPNOTSUPP;

        size_t seed_size = (size_t) r;

        _cleanup_free_ void *seed = malloc(seed_size);
        if (!seed)
                return log_oom_debug();

        r = crypto_random_bytes(seed, seed_size);
        if (r < 0)
                return log_debug_errno(r, "Failed to generate random seed: %m");

        const char *hash_alg_name = tpm2_hash_alg_to_string(parent->publicArea.nameAlg);
        if (!hash_alg_name)
                return -EOPNOTSUPP;

        _cleanup_free_ void *encrypted_seed = NULL;
        size_t encrypted_seed_size;
        r = rsa_oaep_encrypt_bytes(
                        parent_pkey,
                        hash_alg_name,
                        "DUPLICATE",
                        seed,
                        seed_size,
                        &encrypted_seed,
                        &encrypted_seed_size);
        if (r < 0)
                return log_debug_errno(r, "Could not RSA-OAEP encrypt random seed: %m");

        *ret_seed = TAKE_PTR(seed);
        *ret_seed_size = seed_size;
        *ret_encrypted_seed = TAKE_PTR(encrypted_seed);
        *ret_encrypted_seed_size = encrypted_seed_size;

        return 0;
}

static int tpm2_calculate_seal_ecc_seed(
                const TPM2B_PUBLIC *parent,
                void **ret_seed,
                size_t *ret_seed_size,
                void **ret_encrypted_seed,
                size_t *ret_encrypted_seed_size) {

        TSS2_RC rc;
        int r;

        assert(parent);
        assert(ret_seed);
        assert(ret_seed_size);
        assert(ret_encrypted_seed);
        assert(ret_encrypted_seed_size);

        log_debug("Calculating encrypted seed for ECC sealed object.");

        _cleanup_(EVP_PKEY_freep) EVP_PKEY *parent_pkey = NULL;
        r = tpm2_tpm2b_public_to_openssl_pkey(parent, &parent_pkey);
        if (r < 0)
                return log_debug_errno(r, "Could not convert TPM2B_PUBLIC to OpenSSL PKEY: %m");

        int curve_id;
        r = ecc_pkey_to_curve_x_y(
                        parent_pkey,
                        &curve_id,
                        /* ret_x= */ NULL, /* ret_x_size= */ 0,
                        /* ret_y= */ NULL, /* ret_y_size= */ 0);
        if (r < 0)
                return r;

        _cleanup_(EVP_PKEY_freep) EVP_PKEY *pkey = NULL;
        r = ecc_pkey_new(curve_id, &pkey);
        if (r < 0)
                return r;

        _cleanup_free_ void *shared_secret = NULL;
        size_t shared_secret_size;
        r = ecc_ecdh(pkey, parent_pkey, &shared_secret, &shared_secret_size);
        if (r < 0)
                return log_debug_errno(r, "Could not generate ECC shared secret: %m");

        _cleanup_free_ void *x = NULL, *y = NULL;
        size_t x_size, y_size;
        r = ecc_pkey_to_curve_x_y(pkey, /* curve_id= */ NULL, &x, &x_size, &y, &y_size);
        if (r < 0)
                return log_debug_errno(r, "Could not get ECC get x/y: %m");

        r = TPM2B_ECC_PARAMETER_CHECK_SIZE(x_size);
        if (r < 0)
                return log_debug_errno(r, "ECC point x size %zu is too large: %m", x_size);

        r = TPM2B_ECC_PARAMETER_CHECK_SIZE(y_size);
        if (r < 0)
                return log_debug_errno(r, "ECC point y size %zu is too large: %m", y_size);

        TPMS_ECC_POINT point = {
                .x = TPM2B_ECC_PARAMETER_MAKE(x, x_size),
                .y = TPM2B_ECC_PARAMETER_MAKE(y, y_size),
        };

        _cleanup_free_ void *encrypted_seed = malloc(sizeof(point));
        if (!encrypted_seed)
                return log_oom_debug();

        size_t encrypted_seed_size = 0;
        rc = sym_Tss2_MU_TPMS_ECC_POINT_Marshal(&point, encrypted_seed, sizeof(point), &encrypted_seed_size);
        if (rc != TPM2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal ECC point: %s", sym_Tss2_RC_Decode(rc));

        r = tpm2_hash_alg_to_size(parent->publicArea.nameAlg);
        if (r < 0)
                return -EOPNOTSUPP;

        size_t bits = (size_t) r * 8;

        _cleanup_free_ void *seed = NULL;
        size_t seed_size = 0; /* Explicit initialization to appease gcc */
        r = tpm2_kdfe(parent->publicArea.nameAlg,
                      shared_secret,
                      shared_secret_size,
                      "DUPLICATE",
                      x,
                      x_size,
                      parent->publicArea.unique.ecc.x.buffer,
                      parent->publicArea.unique.ecc.x.size,
                      bits,
                      &seed,
                      &seed_size);
        if (r < 0)
                return log_debug_errno(r, "Could not calculate KDFe: %m");

        *ret_seed = TAKE_PTR(seed);
        *ret_seed_size = seed_size;
        *ret_encrypted_seed = TAKE_PTR(encrypted_seed);
        *ret_encrypted_seed_size = encrypted_seed_size;

        return 0;
}

static int tpm2_calculate_seal_seed(
                const TPM2B_PUBLIC *parent,
                TPM2B_DIGEST *ret_seed,
                TPM2B_ENCRYPTED_SECRET *ret_encrypted_seed) {

        int r;

        assert(parent);
        assert(ret_seed);
        assert(ret_encrypted_seed);

        log_debug("Calculating encrypted seed for sealed object.");

        _cleanup_free_ void *seed = NULL, *encrypted_seed = NULL;
        size_t seed_size = 0, encrypted_seed_size = 0; /* Explicit initialization to appease gcc */
        if (parent->publicArea.type == TPM2_ALG_RSA)
                r = tpm2_calculate_seal_rsa_seed(parent, &seed, &seed_size, &encrypted_seed, &encrypted_seed_size);
        else if (parent->publicArea.type == TPM2_ALG_ECC)
                r = tpm2_calculate_seal_ecc_seed(parent, &seed, &seed_size, &encrypted_seed, &encrypted_seed_size);
        else
                return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
                                       "Unsupported parent key type 0x%" PRIx16, parent->publicArea.type);
        if (r < 0)
                return log_debug_errno(r, "Could not calculate encrypted seed: %m");

        *ret_seed = TPM2B_DIGEST_MAKE(seed, seed_size);
        *ret_encrypted_seed = TPM2B_ENCRYPTED_SECRET_MAKE(encrypted_seed, encrypted_seed_size);

        return 0;
}

#endif /* HAVE_OPENSSL */

int tpm2_calculate_seal(
                TPM2_HANDLE parent_handle,
                const TPM2B_PUBLIC *parent_public,
                const TPMA_OBJECT *attributes,
                const struct iovec *secret,
                const TPM2B_DIGEST *policy,
                const char *pin,
                struct iovec *ret_secret,
                struct iovec *ret_blob,
                struct iovec *ret_serialized_parent) {

#if HAVE_OPENSSL
        int r;

        assert(parent_public);
        assert(iovec_is_valid(secret));
        assert(secret || ret_secret);
        assert(!(secret && ret_secret)); /* Either provide a secret, or we create one, but not both */
        assert(ret_blob);
        assert(ret_serialized_parent);

        log_debug("Calculating sealed object.");

        /* Default to the SRK. */
        if (parent_handle == 0)
                parent_handle = TPM2_SRK_HANDLE;

        switch (TPM2_HANDLE_TYPE(parent_handle)) {
        case TPM2_HT_PERSISTENT:
        case TPM2_HT_NV_INDEX:
                break;
        case TPM2_HT_TRANSIENT:
                log_warning("Handle is transient, sealed secret may not be recoverable.");
                break;
        default:
                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "Handle 0x%" PRIx32 " not persistent, transient, or NV.",
                                       parent_handle);
        }

        _cleanup_(iovec_done_erase) struct iovec generated_secret = {};
        if (!secret) {
                /* No secret provided, generate a random secret. We use SHA256 digest length, though it can
                 * be up to TPM2_MAX_SEALED_DATA. The secret length is not limited to the nameAlg hash
                 * size. */
                generated_secret.iov_len = TPM2_SHA256_DIGEST_SIZE;
                generated_secret.iov_base = malloc(generated_secret.iov_len);
                if (!generated_secret.iov_base)
                        return log_oom_debug();

                r = crypto_random_bytes(generated_secret.iov_base, generated_secret.iov_len);
                if (r < 0)
                        return log_debug_errno(r, "Failed to generate secret key: %m");

                secret = &generated_secret;
        }

        if (secret->iov_len > TPM2_MAX_SEALED_DATA)
                return log_debug_errno(SYNTHETIC_ERRNO(EOVERFLOW),
                                       "Secret size %zu too large, limit is %d bytes.",
                                       secret->iov_len, TPM2_MAX_SEALED_DATA);

        TPM2B_DIGEST random_seed;
        TPM2B_ENCRYPTED_SECRET seed;
        r = tpm2_calculate_seal_seed(parent_public, &random_seed, &seed);
        if (r < 0)
                return r;

        TPM2B_PUBLIC public;
        r = tpm2_calculate_seal_public(parent_public, attributes, policy, &random_seed, secret->iov_base, secret->iov_len, &public);
        if (r < 0)
                return r;

        TPM2B_NAME name;
        r = tpm2_calculate_pubkey_name(&public.publicArea, &name);
        if (r < 0)
                return r;

        TPM2B_PRIVATE private;
        r = tpm2_calculate_seal_private(parent_public, &name, pin, &random_seed, secret->iov_base, secret->iov_len, &private);
        if (r < 0)
                return r;

        _cleanup_(iovec_done) struct iovec blob = {};
        r = tpm2_marshal_blob(&public, &private, &seed, &blob.iov_base, &blob.iov_len);
        if (r < 0)
                return log_debug_errno(r, "Could not create sealed blob: %m");

        TPM2B_NAME parent_name;
        r = tpm2_calculate_pubkey_name(&parent_public->publicArea, &parent_name);
        if (r < 0)
                return r;

        _cleanup_(iovec_done) struct iovec serialized_parent = {};
        r = tpm2_calculate_serialize(
                        parent_handle,
                        &parent_name,
                        parent_public,
                        &serialized_parent.iov_base,
                        &serialized_parent.iov_len);
        if (r < 0)
                return r;

        if (ret_secret)
                *ret_secret = TAKE_STRUCT(generated_secret);
        *ret_blob = TAKE_STRUCT(blob);
        *ret_serialized_parent = TAKE_STRUCT(serialized_parent);

        return 0;
#else /* HAVE_OPENSSL */
        return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "OpenSSL support is disabled.");
#endif
}

int tpm2_seal(Tpm2Context *c,
              uint32_t seal_key_handle,
              const TPM2B_DIGEST *policy,
              const char *pin,
              struct iovec *ret_secret,
              struct iovec *ret_blob,
              uint16_t *ret_primary_alg,
              struct iovec *ret_srk) {

        uint16_t primary_alg = 0;
        int r;

        assert(ret_secret);
        assert(ret_blob);

        /* So here's what we do here: we connect to the TPM2 chip. It persistently contains a "seed" key that
         * is randomized when the TPM2 is first initialized or reset and remains stable across boots. We
         * generate a "primary" key pair derived from that (ECC if possible, RSA as fallback). Given the seed
         * remains fixed this will result in the same key pair whenever we specify the exact same parameters
         * for it. We then create a PCR-bound policy session, which calculates a hash on the current PCR
         * values of the indexes we specify. We then generate a randomized key on the host (which is the key
         * we actually enroll in the LUKS2 keyslots), which we upload into the TPM2, where it is encrypted
         * with the "primary" key, taking the PCR policy session into account. We then download the encrypted
         * key from the TPM2 ("sealing") and marshall it into binary form, which is ultimately placed in the
         * LUKS2 JSON header.
         *
         * The TPM2 "seed" key and "primary" keys never leave the TPM2 chip (and cannot be extracted at
         * all). The random key we enroll in LUKS2 we generate on the host using the Linux random device. It
         * is stored in the LUKS2 JSON only in encrypted form with the "primary" key of the TPM2 chip, thus
         * binding the unlocking to the TPM2 chip. */

        usec_t start = now(CLOCK_MONOTONIC);

        TPMA_OBJECT hmac_attributes =
                        TPMA_OBJECT_FIXEDTPM |
                        TPMA_OBJECT_FIXEDPARENT;

        /* If protected by PIN, a user-selected low-entropy password, enable DA protection.
           Without a PIN, the key's left protected only by a PCR policy, which does not benefit
           from DA protection. */
        hmac_attributes |= pin ? 0 : TPMA_OBJECT_NODA;

        /* We use a keyed hash object (i.e. HMAC) to store the secret key we want to use for unlocking the
         * LUKS2 volume with. We don't ever use for HMAC/keyed hash operations however, we just use it
         * because it's a key type that is universally supported and suitable for symmetric binary blobs. */
        TPMT_PUBLIC hmac_template = {
                .type = TPM2_ALG_KEYEDHASH,
                .nameAlg = TPM2_ALG_SHA256,
                .objectAttributes = hmac_attributes,
                .parameters.keyedHashDetail.scheme.scheme = TPM2_ALG_NULL,
                .unique.keyedHash.size = SHA256_DIGEST_SIZE,
                .authPolicy = policy ? *policy : TPM2B_DIGEST_MAKE(NULL, TPM2_SHA256_DIGEST_SIZE),
        };

        TPMS_SENSITIVE_CREATE hmac_sensitive = {
                .data.size = hmac_template.unique.keyedHash.size,
        };

        CLEANUP_ERASE(hmac_sensitive);

        if (pin) {
                r = tpm2_auth_value_from_pin(TPM2_ALG_SHA256, pin, &hmac_sensitive.userAuth);
                if (r < 0)
                        return r;
        }

        assert(sizeof(hmac_sensitive.data.buffer) >= hmac_sensitive.data.size);

        (void) tpm2_credit_random(c);

        log_debug("Generating secret key data.");

        r = crypto_random_bytes(hmac_sensitive.data.buffer, hmac_sensitive.data.size);
        if (r < 0)
                return log_debug_errno(r, "Failed to generate secret key: %m");

        _cleanup_(tpm2_handle_freep) Tpm2Handle *primary_handle = NULL;
        if (ret_srk) {
                _cleanup_(Esys_Freep) TPM2B_PUBLIC *primary_public = NULL;

                if (IN_SET(seal_key_handle, 0, TPM2_SRK_HANDLE)) {
                        r = tpm2_get_or_create_srk(
                                        c,
                                        /* session= */ NULL,
                                        &primary_public,
                                        /* ret_name= */ NULL,
                                        /* ret_qname= */ NULL,
                                        &primary_handle);
                        if (r < 0)
                                return r;
                } else if (IN_SET(TPM2_HANDLE_TYPE(seal_key_handle), TPM2_HT_TRANSIENT, TPM2_HT_PERSISTENT)) {
                        r = tpm2_index_to_handle(
                                        c,
                                        seal_key_handle,
                                        /* session= */ NULL,
                                        &primary_public,
                                        /* ret_name= */ NULL,
                                        /* ret_qname= */ NULL,
                                        &primary_handle);
                        if (r < 0)
                                return r;
                        if (r == 0)
                                /* We do NOT automatically create anything other than the SRK */
                                return log_debug_errno(SYNTHETIC_ERRNO(ENOENT),
                                                       "No handle found at index 0x%" PRIx32, seal_key_handle);
                } else
                        return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
                                               "Seal key handle 0x%" PRIx32 " is neither transient nor persistent.",
                                               seal_key_handle);

                primary_alg = primary_public->publicArea.type;
        } else {
                if (seal_key_handle != 0)
                        log_debug("Using primary alg sealing, but seal key handle also provided; ignoring seal key handle.");

                /* TODO: force all callers to provide ret_srk, so we can stop sealing with the legacy templates. */
                primary_alg = TPM2_ALG_ECC;

                TPM2B_PUBLIC template = {
                        .size = sizeof(TPMT_PUBLIC),
                };
                r = tpm2_get_legacy_template(primary_alg, &template.publicArea);
                if (r < 0)
                        return log_debug_errno(r, "Could not get legacy ECC template: %m");

                if (!tpm2_supports_tpmt_public(c, &template.publicArea)) {
                        primary_alg = TPM2_ALG_RSA;

                        r = tpm2_get_legacy_template(primary_alg, &template.publicArea);
                        if (r < 0)
                                return log_debug_errno(r, "Could not get legacy RSA template: %m");

                        if (!tpm2_supports_tpmt_public(c, &template.publicArea))
                                return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
                                                       "TPM does not support either ECC or RSA legacy template.");
                }

                r = tpm2_create_primary(
                                c,
                                /* session= */ NULL,
                                &template,
                                /* sensitive= */ NULL,
                                /* ret_public= */ NULL,
                                &primary_handle);
                if (r < 0)
                        return r;
        }

        _cleanup_(tpm2_handle_freep) Tpm2Handle *encryption_session = NULL;
        r = tpm2_make_encryption_session(c, primary_handle, /* bind_key= */ NULL, &encryption_session);
        if (r < 0)
                return r;

        _cleanup_(Esys_Freep) TPM2B_PUBLIC *public = NULL;
        _cleanup_(Esys_Freep) TPM2B_PRIVATE *private = NULL;
        r = tpm2_create(c, primary_handle, encryption_session, &hmac_template, &hmac_sensitive, &public, &private);
        if (r < 0)
                return r;

        _cleanup_(iovec_done_erase) struct iovec secret = {};
        secret.iov_base = memdup(hmac_sensitive.data.buffer, hmac_sensitive.data.size);
        if (!secret.iov_base)
                return log_oom_debug();
        secret.iov_len = hmac_sensitive.data.size;

        log_debug("Marshalling private and public part of HMAC key.");

        _cleanup_(iovec_done) struct iovec blob = {};
        r = tpm2_marshal_blob(public, private, /* seed= */ NULL, &blob.iov_base, &blob.iov_len);
        if (r < 0)
                return log_debug_errno(r, "Could not create sealed blob: %m");

        if (DEBUG_LOGGING)
                log_debug("Completed TPM2 key sealing in %s.", FORMAT_TIMESPAN(now(CLOCK_MONOTONIC) - start, 1));

        if (ret_srk) {
                _cleanup_(iovec_done) struct iovec srk = {};
                _cleanup_(Esys_Freep) void *tmp = NULL;
                size_t tmp_size;

                r = tpm2_serialize(c, primary_handle, &tmp, &tmp_size);
                if (r < 0)
                        return r;

                /*
                 * make a copy since we don't want the caller to understand that
                 * ESYS allocated the pointer. It would make tracking what deallocator
                 * to use for srk in which context a PITA.
                 */
                srk.iov_base = memdup(tmp, tmp_size);
                if (!srk.iov_base)
                        return log_oom_debug();
                srk.iov_len = tmp_size;

                *ret_srk = TAKE_STRUCT(srk);
        }

        *ret_secret = TAKE_STRUCT(secret);
        *ret_blob = TAKE_STRUCT(blob);

        if (ret_primary_alg)
                *ret_primary_alg = primary_alg;

        return 0;
}

#define RETRY_UNSEAL_MAX 30u

int tpm2_unseal(Tpm2Context *c,
                uint32_t hash_pcr_mask,
                uint16_t pcr_bank,
                const struct iovec *pubkey,
                uint32_t pubkey_pcr_mask,
                JsonVariant *signature,
                const char *pin,
                const Tpm2PCRLockPolicy *pcrlock_policy,
                uint16_t primary_alg,
                const struct iovec *blob,
                const struct iovec *known_policy_hash,
                const struct iovec *srk,
                struct iovec *ret_secret) {

        TSS2_RC rc;
        int r;

        assert(iovec_is_set(blob));
        assert(iovec_is_valid(known_policy_hash));
        assert(iovec_is_valid(pubkey));
        assert(ret_secret);

        assert(TPM2_PCR_MASK_VALID(hash_pcr_mask));
        assert(TPM2_PCR_MASK_VALID(pubkey_pcr_mask));

        /* So here's what we do here: We connect to the TPM2 chip. As we do when sealing we generate a
         * "primary" key on the TPM2 chip, with the same parameters as well as a PCR-bound policy session.
         * Given we pass the same parameters, this will result in the same "primary" key, and same policy
         * hash (the latter of course, only if the PCR values didn't change in between). We unmarshal the
         * encrypted key we stored in the LUKS2 JSON token header and upload it into the TPM2, where it is
         * decrypted if the seed and the PCR policy were right ("unsealing"). We then download the result,
         * and use it to unlock the LUKS2 volume. */

        usec_t start = now(CLOCK_MONOTONIC);

        TPM2B_PUBLIC public;
        TPM2B_PRIVATE private;
        TPM2B_ENCRYPTED_SECRET seed = {};
        r = tpm2_unmarshal_blob(blob->iov_base, blob->iov_len, &public, &private, &seed);
        if (r < 0)
                return log_debug_errno(r, "Could not extract parts from blob: %m");

        /* Older code did not save the pcr_bank, and unsealing needed to detect the best pcr bank to use,
         * so we need to handle that legacy situation. */
        if (pcr_bank == UINT16_MAX) {
                r = tpm2_get_best_pcr_bank(c, hash_pcr_mask|pubkey_pcr_mask, &pcr_bank);
                if (r < 0)
                        return r;
        }

        _cleanup_(tpm2_handle_freep) Tpm2Handle *primary_handle = NULL;
        if (iovec_is_set(srk)) {
                r = tpm2_deserialize(c, srk->iov_base, srk->iov_len, &primary_handle);
                if (r < 0)
                        return r;
        } else if (primary_alg != 0) {
                TPM2B_PUBLIC template = {
                        .size = sizeof(TPMT_PUBLIC),
                };
                r = tpm2_get_legacy_template(primary_alg, &template.publicArea);
                if (r < 0)
                        return log_debug_errno(r, "Could not get legacy template: %m");

                r = tpm2_create_primary(
                                c,
                                /* session= */ NULL,
                                &template,
                                /* sensitive= */ NULL,
                                /* ret_public= */ NULL,
                                &primary_handle);
                if (r < 0)
                        return r;
        } else
                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "No SRK or primary alg provided.");

        if (seed.size > 0) {
                /* This is a calculated (or duplicated) sealed object, and must be imported. */
                _cleanup_free_ TPM2B_PRIVATE *imported_private = NULL;
                r = tpm2_import(c,
                                primary_handle,
                                /* session= */ NULL,
                                &public,
                                &private,
                                &seed,
                                /* encryption_key= */ NULL,
                                /* symmetric= */ NULL,
                                &imported_private);
                if (r < 0)
                        return r;

                private = *imported_private;
        }

        log_debug("Loading HMAC key into TPM.");

        /*
         * Nothing sensitive on the bus, no need for encryption. Even if an attacker
         * gives you back a different key, the session initiation will fail. In the
         * SRK model, the tpmKey is verified. In the non-srk model, with pin, the bindKey
         * provides protections.
         */
        _cleanup_(tpm2_handle_freep) Tpm2Handle *hmac_key = NULL;
        r = tpm2_load(c, primary_handle, NULL, &public, &private, &hmac_key);
        if (r < 0)
                return r;

        TPM2B_PUBLIC pubkey_tpm2b;
        _cleanup_(iovec_done) struct iovec fp = {};
        if (iovec_is_set(pubkey)) {
                r = tpm2_tpm2b_public_from_pem(pubkey->iov_base, pubkey->iov_len, &pubkey_tpm2b);
                if (r < 0)
                        return log_debug_errno(r, "Could not create TPMT_PUBLIC: %m");

                r = tpm2_tpm2b_public_to_fingerprint(&pubkey_tpm2b, &fp.iov_base, &fp.iov_len);
                if (r < 0)
                        return log_debug_errno(r, "Could not get key fingerprint: %m");
        }

        /*
         * if a pin is set for the seal object, use it to bind the session
         * key to that object. This prevents active bus interposers from
         * faking a TPM and seeing the unsealed value. An active interposer
         * could fake a TPM, satisfying the encrypted session, and just
         * forward everything to the *real* TPM.
         */
        r = tpm2_set_auth(c, hmac_key, pin);
        if (r < 0)
                return r;

        _cleanup_(Esys_Freep) TPM2B_SENSITIVE_DATA* unsealed = NULL;
        for (unsigned i = RETRY_UNSEAL_MAX;; i--) {
                _cleanup_(tpm2_handle_freep) Tpm2Handle *encryption_session = NULL;
                r = tpm2_make_encryption_session(c, primary_handle, hmac_key, &encryption_session);
                if (r < 0)
                        return r;

                _cleanup_(tpm2_handle_freep) Tpm2Handle *policy_session = NULL;
                _cleanup_(Esys_Freep) TPM2B_DIGEST *policy_digest = NULL;
                r = tpm2_make_policy_session(
                                c,
                                primary_handle,
                                encryption_session,
                                &policy_session);
                if (r < 0)
                        return r;

                r = tpm2_build_sealing_policy(
                                c,
                                policy_session,
                                hash_pcr_mask,
                                pcr_bank,
                                iovec_is_set(pubkey) ? &pubkey_tpm2b : NULL,
                                fp.iov_base, fp.iov_len,
                                pubkey_pcr_mask,
                                signature,
                                !!pin,
                                pcrlock_policy,
                                &policy_digest);
                if (r < 0)
                        return r;

                /* If we know the policy hash to expect, and it doesn't match, we can shortcut things here, and not
                 * wait until the TPM2 tells us to go away. */
                if (iovec_is_set(known_policy_hash) && memcmp_nn(policy_digest->buffer,
                                                                 policy_digest->size,
                                                                 known_policy_hash->iov_base,
                                                                 known_policy_hash->iov_len) != 0) {
#if HAVE_OPENSSL
                        if (iovec_is_set(pubkey) &&
                            pubkey_tpm2b.publicArea.type == TPM2_ALG_RSA &&
                            pubkey_tpm2b.publicArea.parameters.rsaDetail.exponent == TPM2_RSA_DEFAULT_EXPONENT) {
                                /* Due to bug #30546, if using RSA pubkey with the default exponent, we may
                                 * need to set the exponent to the TPM special-case value of 0 and retry. */
                                log_debug("Policy hash mismatch, retrying with RSA pubkey exponent set to 0.");
                                pubkey_tpm2b.publicArea.parameters.rsaDetail.exponent = 0;
                                continue;
                        } else
#endif
                                return log_debug_errno(SYNTHETIC_ERRNO(EPERM),
                                                       "Current policy digest does not match stored policy digest, cancelling "
                                                       "TPM2 authentication attempt.");
                }

                log_debug("Unsealing HMAC key.");

                rc = sym_Esys_Unseal(
                                c->esys_context,
                                hmac_key->esys_handle,
                                policy_session->esys_handle,
                                encryption_session->esys_handle, /* use HMAC session to enable parameter encryption */
                                ESYS_TR_NONE,
                                &unsealed);
                if (rc == TSS2_RC_SUCCESS)
                        break;
                if (rc != TPM2_RC_PCR_CHANGED || i == 0)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                               "Failed to unseal HMAC key in TPM: %s", sym_Tss2_RC_Decode(rc));
                log_debug("A PCR value changed during the TPM2 policy session, restarting HMAC key unsealing (%u tries left).", i);
        }

        _cleanup_(iovec_done_erase) struct iovec secret = {};
        secret.iov_base = memdup(unsealed->buffer, unsealed->size);
        explicit_bzero_safe(unsealed->buffer, unsealed->size);
        if (!secret.iov_base)
                return log_oom_debug();
        secret.iov_len = unsealed->size;

        if (DEBUG_LOGGING)
                log_debug("Completed TPM2 key unsealing in %s.", FORMAT_TIMESPAN(now(CLOCK_MONOTONIC) - start, 1));

        *ret_secret = TAKE_STRUCT(secret);

        return 0;
}

static TPM2_HANDLE generate_random_nv_index(void) {
        return TPM2_NV_INDEX_FIRST + (TPM2_HANDLE) random_u64_range(TPM2_NV_INDEX_LAST - TPM2_NV_INDEX_FIRST + 1);
}

int tpm2_define_policy_nv_index(
                Tpm2Context *c,
                const Tpm2Handle *session,
                TPM2_HANDLE requested_nv_index,
                const TPM2B_DIGEST *write_policy,
                TPM2_HANDLE *ret_nv_index,
                Tpm2Handle **ret_nv_handle,
                TPM2B_NV_PUBLIC *ret_nv_public) {

        _cleanup_(tpm2_handle_freep) Tpm2Handle *new_handle = NULL;
        TSS2_RC rc;
        int r;

        assert(c);

        /* Allocates an nvindex to store a policy for use in PolicyAuthorizeNV in. This is where pcrlock then
         * stores its predicted PCR policies in. If 'requested_nv_index' will try to allocate the specified
         * nvindex, otherwise will find a free one, and use that. */

        r = tpm2_handle_new(c, &new_handle);
        if (r < 0)
                return r;

        new_handle->flush = false; /* This is a persistent NV index, don't flush hence */

        for (unsigned try = 0; try < 25U; try++) {
                TPM2_HANDLE nv_index;

                if (requested_nv_index != 0)
                        nv_index = requested_nv_index;
                else
                        nv_index = generate_random_nv_index();

                TPM2B_NV_PUBLIC public_info = {
                        .size = sizeof_field(TPM2B_NV_PUBLIC, nvPublic),
                        .nvPublic = {
                                .nvIndex = nv_index,
                                .nameAlg = TPM2_ALG_SHA256,
                                .attributes = TPM2_NT_ORDINARY | TPMA_NV_WRITEALL | TPMA_NV_POLICYWRITE | TPMA_NV_OWNERREAD,
                                .dataSize = offsetof(TPMT_HA, digest) + tpm2_hash_alg_to_size(TPM2_ALG_SHA256),
                        },
                };

                if (write_policy)
                        public_info.nvPublic.authPolicy = *write_policy;

                rc = sym_Esys_NV_DefineSpace(
                                c->esys_context,
                                /* authHandle= */ ESYS_TR_RH_OWNER,
                                /* shandle1= */ session ? session->esys_handle : ESYS_TR_PASSWORD,
                                /* shandle2= */ ESYS_TR_NONE,
                                /* shandle3= */ ESYS_TR_NONE,
                                /* auth= */ NULL,
                                &public_info,
                                &new_handle->esys_handle);

                if (rc == TSS2_RC_SUCCESS) {
                        log_debug("NV Index 0x%" PRIx32 " successfully allocated.", nv_index);

                        if (ret_nv_index)
                                *ret_nv_index = nv_index;

                        if (ret_nv_handle)
                                *ret_nv_handle = TAKE_PTR(new_handle);

                        if (ret_nv_public)
                                *ret_nv_public = public_info;

                        return 0;
                }
                if (rc != TPM2_RC_NV_DEFINED)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                               "Failed to allocate NV index: %s", sym_Tss2_RC_Decode(rc));

                if (requested_nv_index != 0) {
                        assert(nv_index == requested_nv_index);
                        return log_debug_errno(SYNTHETIC_ERRNO(EEXIST),
                                               "Requested NV index 0x%" PRIx32 " already taken.", requested_nv_index);
                }

                log_debug("NV index 0x%" PRIu32 " already taken, trying another one (%u tries left)", nv_index, try);
        }

        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                               "Too many attempts trying to allocate NV index: %s", sym_Tss2_RC_Decode(rc));
}

int tpm2_write_policy_nv_index(
                Tpm2Context *c,
                const Tpm2Handle *policy_session,
                TPM2_HANDLE nv_index,
                const Tpm2Handle *nv_handle,
                const TPM2B_DIGEST *policy_digest) {

        TSS2_RC rc;

        assert(c);
        assert(policy_session);
        assert(nv_handle);
        assert(policy_digest);

        if (policy_digest->size != tpm2_hash_alg_to_size(TPM2_ALG_SHA256))
                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Policy to store in NV index has wrong size.");

        TPMT_HA ha = {
                .hashAlg = TPM2_ALG_SHA256,
        };
        assert(policy_digest->size <= sizeof_field(TPMT_HA, digest));
        memcpy_safe(&ha.digest, policy_digest->buffer, policy_digest->size);

        TPM2B_MAX_NV_BUFFER buffer = {};
        size_t written = 0;
        rc = sym_Tss2_MU_TPMT_HA_Marshal(&ha, buffer.buffer, sizeof(buffer.buffer), &written);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to marshal policy digest.");

        buffer.size = written;

        rc = sym_Esys_NV_Write(
                        c->esys_context,
                        /* authHandle= */ nv_handle->esys_handle,
                        /* nvIndex= */ nv_handle->esys_handle,
                        /* shandle1= */ policy_session->esys_handle,
                        /* shandle2= */ ESYS_TR_NONE,
                        /* shandle3= */ ESYS_TR_NONE,
                        &buffer,
                        /* offset= */ 0);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to write NV index: %s", sym_Tss2_RC_Decode(rc));

        if (DEBUG_LOGGING) {
                _cleanup_free_ char *h = NULL;
                h = hexmem(policy_digest->buffer, policy_digest->size);
                log_debug("Written policy digest %s to NV index 0x%x", strnull(h), nv_index);
        }

        return 0;
}

int tpm2_undefine_policy_nv_index(
                Tpm2Context *c,
                const Tpm2Handle *session,
                TPM2_HANDLE nv_index,
                const Tpm2Handle *nv_handle) {

        TSS2_RC rc;

        assert(c);
        assert(nv_handle);

        rc = sym_Esys_NV_UndefineSpace(
                        c->esys_context,
                        /* authHandle= */ ESYS_TR_RH_OWNER,
                        /* nvIndex= */ nv_handle->esys_handle,
                        /* shandle1= */ session ? session->esys_handle : ESYS_TR_NONE,
                        /* shandle2= */ ESYS_TR_NONE,
                        /* shandle3= */ ESYS_TR_NONE);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to undefine NV index: %s", sym_Tss2_RC_Decode(rc));

        log_debug("Undefined NV index 0x%x", nv_index);
        return 0;
}

int tpm2_seal_data(
                Tpm2Context *c,
                const struct iovec *data,
                const Tpm2Handle *primary_handle,
                const Tpm2Handle *encryption_session,
                const TPM2B_DIGEST *policy,
                struct iovec *ret_public,
                struct iovec *ret_private) {

        int r;

        assert(c);
        assert(data);
        assert(primary_handle);

        /* This is a generic version of tpm2_seal(), that doesn't imply any policy or any specific
         * combination of the two keypairs in their marshalling. tpm2_seal() is somewhat specific to the FDE
         * usecase. We probably should migrate tpm2_seal() to use tpm2_seal_data() eventually. */

        if (data->iov_len >= sizeof_field(TPMS_SENSITIVE_CREATE, data.buffer))
                return -E2BIG;

        TPMT_PUBLIC hmac_template = {
                .type = TPM2_ALG_KEYEDHASH,
                .nameAlg = TPM2_ALG_SHA256,
                .objectAttributes = TPMA_OBJECT_FIXEDTPM | TPMA_OBJECT_FIXEDPARENT,
                .parameters.keyedHashDetail.scheme.scheme = TPM2_ALG_NULL,
                .unique.keyedHash.size = data->iov_len,
                .authPolicy = policy ? *policy : TPM2B_DIGEST_MAKE(NULL, TPM2_SHA256_DIGEST_SIZE),
        };

        TPMS_SENSITIVE_CREATE hmac_sensitive = {
                .data.size = hmac_template.unique.keyedHash.size,
        };

        CLEANUP_ERASE(hmac_sensitive);

        memcpy_safe(hmac_sensitive.data.buffer, data->iov_base, data->iov_len);

        _cleanup_(Esys_Freep) TPM2B_PUBLIC *public = NULL;
        _cleanup_(Esys_Freep) TPM2B_PRIVATE *private = NULL;
        r = tpm2_create(c, primary_handle, encryption_session, &hmac_template, &hmac_sensitive, &public, &private);
        if (r < 0)
                return r;

        _cleanup_(iovec_done) struct iovec public_blob = {}, private_blob = {};

        r = tpm2_marshal_private(private, &private_blob.iov_base, &private_blob.iov_len);
        if (r < 0)
                return r;

        r = tpm2_marshal_public(public, &public_blob.iov_base, &public_blob.iov_len);
        if (r < 0)
                return r;

        if (ret_public)
                *ret_public = TAKE_STRUCT(public_blob);
        if (ret_private)
                *ret_private = TAKE_STRUCT(private_blob);

        return 0;
}

int tpm2_unseal_data(
                Tpm2Context *c,
                const struct iovec *public_blob,
                const struct iovec *private_blob,
                const Tpm2Handle *primary_handle,
                const Tpm2Handle *policy_session,
                const Tpm2Handle *encryption_session,
                struct iovec *ret_data) {

        TSS2_RC rc;
        int r;

        assert(c);
        assert(public_blob);
        assert(private_blob);
        assert(primary_handle);

        TPM2B_PUBLIC public;
        r = tpm2_unmarshal_public(public_blob->iov_base, public_blob->iov_len, &public);
        if (r < 0)
                return r;

        TPM2B_PRIVATE private;
        r = tpm2_unmarshal_private(private_blob->iov_base, private_blob->iov_len, &private);
        if (r < 0)
                return r;

        _cleanup_(tpm2_handle_freep) Tpm2Handle *what = NULL;
        r = tpm2_load(c, primary_handle, NULL, &public, &private, &what);
        if (r < 0)
                return r;

        _cleanup_(Esys_Freep) TPM2B_SENSITIVE_DATA* unsealed = NULL;
        rc = sym_Esys_Unseal(
                        c->esys_context,
                        what->esys_handle,
                        policy_session ? policy_session->esys_handle : ESYS_TR_NONE,
                        encryption_session ? encryption_session->esys_handle : ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        &unsealed);
        if (rc == TPM2_RC_PCR_CHANGED)
                return log_debug_errno(SYNTHETIC_ERRNO(ESTALE),
                                       "PCR changed while unsealing.");
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                       "Failed to unseal data: %s", sym_Tss2_RC_Decode(rc));

        _cleanup_(iovec_done) struct iovec d = {};
        d = IOVEC_MAKE(memdup(unsealed->buffer, unsealed->size), unsealed->size);

        explicit_bzero_safe(unsealed->buffer, unsealed->size);

        if (!d.iov_base)
                return log_oom_debug();

        *ret_data = TAKE_STRUCT(d);
        return 0;
}
#endif /* HAVE_TPM2 */

int tpm2_list_devices(void) {
#if HAVE_TPM2
        _cleanup_(table_unrefp) Table *t = NULL;
        _cleanup_closedir_ DIR *d = NULL;
        int r;

        r = dlopen_tpm2();
        if (r < 0)
                return log_error_errno(r, "TPM2 support is not installed.");

        t = table_new("path", "device", "driver");
        if (!t)
                return log_oom();

        d = opendir("/sys/class/tpmrm");
        if (!d) {
                log_full_errno(errno == ENOENT ? LOG_DEBUG : LOG_ERR, errno, "Failed to open /sys/class/tpmrm: %m");
                if (errno != ENOENT)
                        return -errno;
        } else {
                for (;;) {
                        _cleanup_free_ char *device_path = NULL, *device = NULL, *driver_path = NULL, *driver = NULL, *node = NULL;
                        struct dirent *de;

                        de = readdir_no_dot(d);
                        if (!de)
                                break;

                        device_path = path_join("/sys/class/tpmrm", de->d_name, "device");
                        if (!device_path)
                                return log_oom();

                        r = readlink_malloc(device_path, &device);
                        if (r < 0)
                                log_debug_errno(r, "Failed to read device symlink %s, ignoring: %m", device_path);
                        else {
                                driver_path = path_join(device_path, "driver");
                                if (!driver_path)
                                        return log_oom();

                                r = readlink_malloc(driver_path, &driver);
                                if (r < 0)
                                        log_debug_errno(r, "Failed to read driver symlink %s, ignoring: %m", driver_path);
                        }

                        node = path_join("/dev", de->d_name);
                        if (!node)
                                return log_oom();

                        r = table_add_many(
                                        t,
                                        TABLE_PATH, node,
                                        TABLE_STRING, device ? last_path_component(device) : NULL,
                                        TABLE_STRING, driver ? last_path_component(driver) : NULL);
                        if (r < 0)
                                return table_log_add_error(r);
                }
        }

        if (table_isempty(t)) {
                log_info("No suitable TPM2 devices found.");
                return 0;
        }

        r = table_print(t, stdout);
        if (r < 0)
                return log_error_errno(r, "Failed to show device table: %m");

        return 0;
#else
        return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
                               "TPM2 not supported on this build.");
#endif
}

int tpm2_find_device_auto(char **ret) {
#if HAVE_TPM2
        _cleanup_closedir_ DIR *d = NULL;
        int r;

        r = dlopen_tpm2();
        if (r < 0)
                return log_debug_errno(r, "TPM2 support is not installed.");

        d = opendir("/sys/class/tpmrm");
        if (!d) {
                log_debug_errno(errno, "Failed to open /sys/class/tpmrm: %m");
                if (errno != ENOENT)
                        return -errno;
        } else {
                _cleanup_free_ char *node = NULL;

                for (;;) {
                        struct dirent *de;

                        de = readdir_no_dot(d);
                        if (!de)
                                break;

                        if (node)
                                return log_debug_errno(SYNTHETIC_ERRNO(ENOTUNIQ),
                                                       "More than one TPM2 (tpmrm) device found.");

                        node = path_join("/dev", de->d_name);
                        if (!node)
                                return log_oom_debug();
                }

                if (node) {
                        *ret = TAKE_PTR(node);
                        return 0;
                }
        }

        return log_debug_errno(SYNTHETIC_ERRNO(ENODEV), "No TPM2 (tpmrm) device found.");
#else
        return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP),
                               "TPM2 not supported on this build.");
#endif
}

#if HAVE_TPM2
static const char* tpm2_userspace_event_type_table[_TPM2_USERSPACE_EVENT_TYPE_MAX] = {
        [TPM2_EVENT_PHASE]      = "phase",
        [TPM2_EVENT_FILESYSTEM] = "filesystem",
        [TPM2_EVENT_VOLUME_KEY] = "volume-key",
        [TPM2_EVENT_MACHINE_ID] = "machine-id",
};

DEFINE_STRING_TABLE_LOOKUP(tpm2_userspace_event_type, Tpm2UserspaceEventType);

const char *tpm2_userspace_log_path(void) {
        return secure_getenv("SYSTEMD_MEASURE_LOG_USERSPACE") ?: "/run/log/systemd/tpm2-measure.log";
}

const char *tpm2_firmware_log_path(void) {
        return secure_getenv("SYSTEMD_MEASURE_LOG_FIRMWARE") ?: "/sys/kernel/security/tpm0/binary_bios_measurements";
}

#if HAVE_OPENSSL
static int tpm2_userspace_log_open(void) {
        _cleanup_close_ int fd = -EBADF;
        struct stat st;
        const char *e;
        int r;

        e = tpm2_userspace_log_path();
        (void) mkdir_parents(e, 0755);

        /* We use access mode 0600 here (even though the measurements should not strictly be confidential),
         * because we use BSD file locking on it, and if anyone but root can access the file they can also
         * lock it, which we want to avoid. */
        fd = open(e, O_CREAT|O_WRONLY|O_CLOEXEC|O_NOCTTY|O_NOFOLLOW, 0600);
        if (fd < 0)
                return log_debug_errno(errno, "Failed to open TPM log file '%s' for writing, ignoring: %m", e);

        if (flock(fd, LOCK_EX) < 0)
                return log_debug_errno(errno, "Failed to lock TPM log file '%s', ignoring: %m", e);

        if (fstat(fd, &st) < 0)
                return log_debug_errno(errno, "Failed to fstat TPM log file '%s', ignoring: %m", e);

        r = stat_verify_regular(&st);
        if (r < 0)
                return log_debug_errno(r, "TPM log file '%s' is not regular, ignoring: %m", e);

        /* We set the sticky bit when we are about to append to the log file. We'll unset it afterwards
         * again. If we manage to take a lock on a file that has it set we know we didn't write it fully and
         * it is corrupted. Ideally we'd like to use user xattrs for this, but unfortunately tmpfs (which is
         * our assumed backend fs) doesn't know user xattrs. */
        if (st.st_mode & S_ISVTX)
                return log_debug_errno(SYNTHETIC_ERRNO(ESTALE), "TPM log file '%s' aborted, ignoring.", e);

        if (fchmod(fd, 0600 | S_ISVTX) < 0)
                return log_debug_errno(errno, "Failed to chmod() TPM log file '%s', ignoring: %m", e);

        return TAKE_FD(fd);
}

static int tpm2_userspace_log(
                int fd,
                unsigned pcr_index,
                const TPML_DIGEST_VALUES *values,
                Tpm2UserspaceEventType event_type,
                const char *description) {

        _cleanup_(json_variant_unrefp) JsonVariant *v = NULL, *array = NULL;
        _cleanup_free_ char *f = NULL;
        sd_id128_t boot_id;
        int r;

        assert(values);
        assert(values->count > 0);

        /* We maintain a local PCR measurement log. This implements a subset of the TCG Canonical Event Log
         * Format – the JSON flavour –
         * (https://trustedcomputinggroup.org/resource/canonical-event-log-format/), but departs in certain
         * ways from it, specifically:
         *
         * - We don't write out a recnum. It's a bit too vaguely defined which means we'd have to read
         *   through the whole logs (include firmware logs) before knowing what the next value is we should
         *   use. Hence we simply don't write this out as append-time, and instead expect a consumer to add
         *   it in when it uses the data.
         *
         * - We write this out in RFC 7464 application/json-seq rather than as a JSON array. Writing this as
         *   JSON array would mean that for each appending we'd have to read the whole log file fully into
         *   memory before writing it out again. We prefer a strictly append-only write pattern however. (RFC
         *   7464 is what jq --seq eats.) Conversion into a proper JSON array is trivial.
         *
         * It should be possible to convert this format in a relatively straight-forward way into the
         * official TCG Canonical Event Log Format on read, by simply adding in a few more fields that can be
         * determined from the full dataset.
         *
         * We set the 'content_type' field to "systemd" to make clear this data is generated by us, and
         * include various interesting fields in the 'content' subobject, including a CLOCK_BOOTTIME
         * timestamp which can be used to order this measurement against possibly other measurements
         * independently done by other subsystems on the system.
         */

        if (fd < 0) /* Apparently tpm2_local_log_open() failed earlier, let's not complain again */
                return 0;

        for (size_t i = 0; i < values->count; i++) {
                const EVP_MD *implementation;
                const char *a;

                assert_se(a = tpm2_hash_alg_to_string(values->digests[i].hashAlg));
                assert_se(implementation = EVP_get_digestbyname(a));

                r = json_variant_append_arrayb(
                                &array, JSON_BUILD_OBJECT(
                                                JSON_BUILD_PAIR_STRING("hashAlg", a),
                                                JSON_BUILD_PAIR("digest", JSON_BUILD_HEX(&values->digests[i].digest, EVP_MD_size(implementation)))));
                if (r < 0)
                        return log_debug_errno(r, "Failed to append digest object to JSON array: %m");
        }

        assert(array);

        r = sd_id128_get_boot(&boot_id);
        if (r < 0)
                return log_debug_errno(r, "Failed to acquire boot ID: %m");

        r = json_build(&v, JSON_BUILD_OBJECT(
                                       JSON_BUILD_PAIR("pcr", JSON_BUILD_UNSIGNED(pcr_index)),
                                       JSON_BUILD_PAIR("digests", JSON_BUILD_VARIANT(array)),
                                       JSON_BUILD_PAIR("content_type", JSON_BUILD_STRING("systemd")),
                                       JSON_BUILD_PAIR("content", JSON_BUILD_OBJECT(
                                                                       JSON_BUILD_PAIR_CONDITION(description, "string", JSON_BUILD_STRING(description)),
                                                                       JSON_BUILD_PAIR("bootId", JSON_BUILD_ID128(boot_id)),
                                                                       JSON_BUILD_PAIR("timestamp", JSON_BUILD_UNSIGNED(now(CLOCK_BOOTTIME))),
                                                                       JSON_BUILD_PAIR_CONDITION(event_type >= 0, "eventType", JSON_BUILD_STRING(tpm2_userspace_event_type_to_string(event_type)))))));
        if (r < 0)
                return log_debug_errno(r, "Failed to build log record JSON: %m");

        r = json_variant_format(v, JSON_FORMAT_SEQ, &f);
        if (r < 0)
                return log_debug_errno(r, "Failed to format JSON: %m");

        if (lseek(fd, 0, SEEK_END) < 0)
                return log_debug_errno(errno, "Failed to seek to end of JSON log: %m");

        r = loop_write(fd, f, SIZE_MAX);
        if (r < 0)
                return log_debug_errno(r, "Failed to write JSON data to log: %m");

        if (fsync(fd) < 0)
                return log_debug_errno(errno, "Failed to sync JSON data: %m");

        /* Unset S_ISVTX again */
        if (fchmod(fd, 0600) < 0)
                return log_debug_errno(errno, "Failed to chmod() TPM log file, ignoring: %m");

        r = fsync_full(fd);
        if (r < 0)
                return log_debug_errno(r, "Failed to sync JSON log: %m");

        return 1;
}
#endif

int tpm2_extend_bytes(
                Tpm2Context *c,
                char **banks,
                unsigned pcr_index,
                const void *data,
                size_t data_size,
                const void *secret,
                size_t secret_size,
                Tpm2UserspaceEventType event_type,
                const char *description) {

#if HAVE_OPENSSL
        _cleanup_close_ int log_fd = -EBADF;
        TPML_DIGEST_VALUES values = {};
        TSS2_RC rc;

        assert(c);
        assert(data || data_size == 0);
        assert(secret || secret_size == 0);

        if (data_size == SIZE_MAX)
                data_size = strlen(data);
        if (secret_size == SIZE_MAX)
                secret_size = strlen(secret);

        if (pcr_index >= TPM2_PCRS_MAX)
                return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Can't measure into unsupported PCR %u, refusing.", pcr_index);

        if (strv_isempty(banks))
                return 0;

        STRV_FOREACH(bank, banks) {
                const EVP_MD *implementation;
                int id;

                assert_se(implementation = EVP_get_digestbyname(*bank));

                if (values.count >= ELEMENTSOF(values.digests))
                        return log_debug_errno(SYNTHETIC_ERRNO(E2BIG), "Too many banks selected.");

                if ((size_t) EVP_MD_size(implementation) > sizeof(values.digests[values.count].digest))
                        return log_debug_errno(SYNTHETIC_ERRNO(E2BIG), "Hash result too large for TPM2.");

                id = tpm2_hash_alg_from_string(EVP_MD_name(implementation));
                if (id < 0)
                        return log_debug_errno(id, "Can't map hash name to TPM2.");

                values.digests[values.count].hashAlg = id;

                /* So here's a twist: sometimes we want to measure secrets (e.g. root file system volume
                 * key), but we'd rather not leak a literal hash of the secret to the TPM (given that the
                 * wire is unprotected, and some other subsystem might use the simple, literal hash of the
                 * secret for other purposes, maybe because it needs a shorter secret derived from it for
                 * some unrelated purpose, who knows). Hence we instead measure an HMAC signature of a
                 * private non-secret string instead. */
                if (secret_size > 0) {
                        if (!HMAC(implementation, secret, secret_size, data, data_size, (unsigned char*) &values.digests[values.count].digest, NULL))
                                return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Failed to calculate HMAC of data to measure.");
                } else if (EVP_Digest(data, data_size, (unsigned char*) &values.digests[values.count].digest, NULL, implementation, NULL) != 1)
                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Failed to hash data to measure.");

                values.count++;
        }

        /* Open + lock the log file *before* we start measuring, so that no one else can come between our log
         * and our measurement and change either */
        log_fd = tpm2_userspace_log_open();

        rc = sym_Esys_PCR_Extend(
                        c->esys_context,
                        ESYS_TR_PCR0 + pcr_index,
                        ESYS_TR_PASSWORD,
                        ESYS_TR_NONE,
                        ESYS_TR_NONE,
                        &values);
        if (rc != TSS2_RC_SUCCESS)
                return log_debug_errno(
                                SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                "Failed to measure into PCR %u: %s",
                                pcr_index,
                                sym_Tss2_RC_Decode(rc));

        /* Now, write what we just extended to the log, too. */
        (void) tpm2_userspace_log(log_fd, pcr_index, &values, event_type, description);

        return 0;
#else /* HAVE_OPENSSL */
        return log_debug_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "OpenSSL support is disabled.");
#endif
}

const uint16_t tpm2_hash_algorithms[] = {
        TPM2_ALG_SHA1,
        TPM2_ALG_SHA256,
        TPM2_ALG_SHA384,
        TPM2_ALG_SHA512,
        0,
};

assert_cc(ELEMENTSOF(tpm2_hash_algorithms) == TPM2_N_HASH_ALGORITHMS + 1);

static size_t tpm2_hash_algorithm_index(uint16_t algorithm) {
        for (size_t i = 0; i < TPM2_N_HASH_ALGORITHMS; i++)
                if (tpm2_hash_algorithms[i] == algorithm)
                        return i;

        return SIZE_MAX;
}

TPM2B_DIGEST *tpm2_pcr_prediction_result_get_hash(Tpm2PCRPredictionResult *result, uint16_t alg) {
        size_t alg_idx;

        assert(result);

        alg_idx = tpm2_hash_algorithm_index(alg);
        if (alg_idx == SIZE_MAX) /* Algorithm not known? */
                return NULL;

        if (result->hash[alg_idx].size <= 0) /* No hash value for this algorithm? */
                return NULL;

        return result->hash + alg_idx;
}

void tpm2_pcr_prediction_done(Tpm2PCRPrediction *p) {
        assert(p);

        for (uint32_t pcr = 0; pcr < TPM2_PCRS_MAX; pcr++)
                ordered_set_free(p->results[pcr]);
}

static void tpm2_pcr_prediction_result_hash_func(const Tpm2PCRPredictionResult *banks, struct siphash *state) {
        assert(banks);

        for (size_t i = 0; i < TPM2_N_HASH_ALGORITHMS; i++)
                siphash24_compress_safe(banks->hash[i].buffer, banks->hash[i].size, state);
}

static int tpm2_pcr_prediction_result_compare_func(const Tpm2PCRPredictionResult *a, const Tpm2PCRPredictionResult *b) {
        int r;

        assert(a);
        assert(b);

        for (size_t i = 0; i < TPM2_N_HASH_ALGORITHMS; i++) {
                r = memcmp_nn(a->hash[i].buffer, a->hash[i].size,
                              b->hash[i].buffer, b->hash[i].size);
                if (r != 0)
                        return r;
        }

        return 0;
}

DEFINE_HASH_OPS_WITH_VALUE_DESTRUCTOR(
                tpm2_pcr_prediction_result_hash_ops,
                Tpm2PCRPredictionResult,
                tpm2_pcr_prediction_result_hash_func,
                tpm2_pcr_prediction_result_compare_func,
                Tpm2PCRPredictionResult,
                free);

static Tpm2PCRPredictionResult *find_prediction_result_by_algorithm(OrderedSet *set, Tpm2PCRPredictionResult *result, size_t alg_idx) {
        Tpm2PCRPredictionResult *f;

        assert(result);
        assert(alg_idx != SIZE_MAX);

        f = ordered_set_get(set, result); /* Full match? */
        if (f)
                return f;

        /* If this doesn't match full, then see if there an entry that at least matches by the relevant
         * algorithm (we are fine if predictions are "incomplete" in some algorithms) */

        ORDERED_SET_FOREACH(f, set)
                if (memcmp_nn(result->hash[alg_idx].buffer, result->hash[alg_idx].size,
                              f->hash[alg_idx].buffer, f->hash[alg_idx].size) == 0)
                        return f;

        return NULL;
}

bool tpm2_pcr_prediction_equal(
                Tpm2PCRPrediction *a,
                Tpm2PCRPrediction *b,
                uint16_t algorithm) {

        if (a == b)
                return true;
        if (!a || !b)
                return false;

        if (a->pcrs != b->pcrs)
                return false;

        size_t alg_idx = tpm2_hash_algorithm_index(algorithm);
        if (alg_idx == SIZE_MAX)
                return false;

        for (uint32_t pcr = 0; pcr < TPM2_PCRS_MAX; pcr++) {
                Tpm2PCRPredictionResult *banks;

                ORDERED_SET_FOREACH(banks, a->results[pcr])
                        if (!find_prediction_result_by_algorithm(b->results[pcr], banks, alg_idx))
                                return false;

                ORDERED_SET_FOREACH(banks, b->results[pcr])
                        if (!find_prediction_result_by_algorithm(a->results[pcr], banks, alg_idx))
                                return false;
        }

        return true;
}

int tpm2_pcr_prediction_to_json(
                const Tpm2PCRPrediction *prediction,
                uint16_t algorithm,
                JsonVariant **ret) {

        _cleanup_(json_variant_unrefp) JsonVariant *aj = NULL;
        int r;

        assert(prediction);
        assert(ret);

        for (uint32_t pcr = 0; pcr < TPM2_PCRS_MAX; pcr++) {
                _cleanup_(json_variant_unrefp) JsonVariant *vj = NULL;
                Tpm2PCRPredictionResult *banks;

                if (!FLAGS_SET(prediction->pcrs, UINT32_C(1) << pcr))
                        continue;

                ORDERED_SET_FOREACH(banks, prediction->results[pcr]) {

                        TPM2B_DIGEST *hash = tpm2_pcr_prediction_result_get_hash(banks, algorithm);
                        if (!hash)
                                continue;

                        r = json_variant_append_arrayb(
                                        &vj,
                                        JSON_BUILD_HEX(hash->buffer, hash->size));
                        if (r < 0)
                                return log_error_errno(r, "Failed to append hash variant to JSON array: %m");
                }

                if (!vj)
                        continue;

                r = json_variant_append_arrayb(
                                &aj,
                                JSON_BUILD_OBJECT(
                                                JSON_BUILD_PAIR_INTEGER("pcr", pcr),
                                                JSON_BUILD_PAIR_VARIANT("values", vj)));
                if (r < 0)
                        return log_error_errno(r, "Failed to append PCR variants to JSON array: %m");
        }

        if (!aj) {
                r = json_variant_new_array(&aj, NULL, 0);
                if (r < 0)
                        return r;
        }

        *ret = TAKE_PTR(aj);
        return 0;
}

int tpm2_pcr_prediction_from_json(
                Tpm2PCRPrediction *prediction,
                uint16_t algorithm,
                JsonVariant *aj) {

        int r;

        assert(prediction);

        size_t alg_index = tpm2_hash_algorithm_index(algorithm);
        assert(alg_index < TPM2_N_HASH_ALGORITHMS);

        if (!json_variant_is_array(aj))
                return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "PCR variant array is not an array.");

        JsonVariant *pcr;
        JSON_VARIANT_ARRAY_FOREACH(pcr, aj) {
                JsonVariant *nr, *values;

                nr = json_variant_by_key(pcr, "pcr");
                if (!nr)
                        return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "PCR array entry lacks PCR index field");

                if (!json_variant_is_unsigned(nr) ||
                    json_variant_unsigned(nr) >= TPM2_PCRS_MAX)
                        return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "PCR array entry PCR index is not an integer in the range 0…23");

                values = json_variant_by_key(pcr, "values");
                if (!values)
                        return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "PCR array entry lacks values field");

                if (!json_variant_is_array(values))
                        return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "PCR array entry values field is not an array");

                prediction->pcrs |= UINT32_C(1) << json_variant_unsigned(nr);

                JsonVariant *v;
                JSON_VARIANT_ARRAY_FOREACH(v, values) {
                        _cleanup_free_ void *buffer = NULL;
                        size_t size;

                        r = json_variant_unhex(v, &buffer, &size);
                        if (r < 0)
                                return log_error_errno(r, "Failed to decode PCR policy array hash value");

                        if (size <= 0)
                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "PCR policy array hash value is zero.");

                        if (size > sizeof_field(TPM2B_DIGEST, buffer))
                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "PCR policy array hash value is too large.");

                        _cleanup_free_ Tpm2PCRPredictionResult *banks = new0(Tpm2PCRPredictionResult, 1);
                        if (!banks)
                                return log_oom();

                        memcpy(banks->hash[alg_index].buffer, buffer, size);
                        banks->hash[alg_index].size = size;

                        r = ordered_set_ensure_put(prediction->results + json_variant_unsigned(nr), &tpm2_pcr_prediction_result_hash_ops, banks);
                        if (r == -EEXIST) /* Let's allow duplicates */
                                continue;
                        if (r < 0)
                                return log_error_errno(r, "Failed to insert result into set: %m");

                        TAKE_PTR(banks);
                }
        }

        return 0;
}

int tpm2_calculate_policy_super_pcr(
                Tpm2PCRPrediction *prediction,
                uint16_t algorithm,
                TPM2B_DIGEST *pcr_policy) {

        int r;

        assert_se(prediction);
        assert_se(pcr_policy);

        /* Start with a zero policy if not specified otherwise. */
        TPM2B_DIGEST super_pcr_policy_digest = *pcr_policy;

        /* First we look for all PCRs that have exactly one allowed hash value, and generate a single PolicyPCR policy from them */
        _cleanup_free_ Tpm2PCRValue *single_values = NULL;
        size_t n_single_values = 0;
        for (uint32_t pcr = 0; pcr < TPM2_PCRS_MAX; pcr++) {
                if (!FLAGS_SET(prediction->pcrs, UINT32_C(1) << pcr))
                        continue;

                if (ordered_set_size(prediction->results[pcr]) != 1)
                        continue;

                log_debug("Including PCR %" PRIu32 " in single value PolicyPCR expression", pcr);

                Tpm2PCRPredictionResult *banks = ASSERT_PTR(ordered_set_first(prediction->results[pcr]));

                TPM2B_DIGEST *hash = tpm2_pcr_prediction_result_get_hash(banks, algorithm);
                if (!hash)
                        continue;

                if (!GREEDY_REALLOC(single_values, n_single_values + 1))
                        return -ENOMEM;

                single_values[n_single_values++] = TPM2_PCR_VALUE_MAKE(pcr, algorithm, *hash);
        }

        if (n_single_values > 0) {
                /* Evolve policy based on the expected PCR value for what we found. */
                r = tpm2_calculate_policy_pcr(
                                single_values,
                                n_single_values,
                                &super_pcr_policy_digest);
                if (r < 0)
                        return r;
        }

        /* Now deal with the PCRs for which we have variants, i.e. more than one allowed values */
        for (uint32_t pcr = 0; pcr < TPM2_PCRS_MAX; pcr++) {
                _cleanup_free_ TPM2B_DIGEST *pcr_policy_digest_variants = NULL;
                size_t n_pcr_policy_digest_variants = 0;
                Tpm2PCRPredictionResult *banks;

                if (!FLAGS_SET(prediction->pcrs, UINT32_C(1) << pcr))
                        continue;

                if (ordered_set_size(prediction->results[pcr]) <= 1) /* We only care for PCRs with 2 or more variants in this loop */
                        continue;

                if (ordered_set_size(prediction->results[pcr]) > 8)
                        return log_error_errno(SYNTHETIC_ERRNO(E2BIG), "PCR policies with more than 8 alternatives per PCR are currently not supported.");

                ORDERED_SET_FOREACH(banks, prediction->results[pcr]) {
                        /* Start from the super PCR policy from the previous PCR we looked at so far. */
                        TPM2B_DIGEST pcr_policy_digest = super_pcr_policy_digest;

                        TPM2B_DIGEST *hash = tpm2_pcr_prediction_result_get_hash(banks, algorithm);
                        if (!hash)
                                continue;

                        /* Evolve it based on the expected PCR value for this PCR */
                        r = tpm2_calculate_policy_pcr(
                                        &TPM2_PCR_VALUE_MAKE(
                                                        pcr,
                                                        algorithm,
                                                        *hash),
                                        /* n_pcr_values= */ 1,
                                        &pcr_policy_digest);
                        if (r < 0)
                                return r;

                        /* Store away this new variant */
                        if (!GREEDY_REALLOC(pcr_policy_digest_variants, n_pcr_policy_digest_variants + 1))
                                return log_oom();

                        pcr_policy_digest_variants[n_pcr_policy_digest_variants++] = pcr_policy_digest;

                        log_debug("Calculated PCR policy variant %zu for PCR %" PRIu32, n_pcr_policy_digest_variants, pcr);
                }

                assert_se(n_pcr_policy_digest_variants >= 2);
                assert_se(n_pcr_policy_digest_variants <= 8);

                /* Now combine all our variant into one OR policy */
                r = tpm2_calculate_policy_or(
                                pcr_policy_digest_variants,
                                n_pcr_policy_digest_variants,
                                &super_pcr_policy_digest);
                if (r < 0)
                        return r;

                log_debug("Combined %zu variants in OR policy.", n_pcr_policy_digest_variants);
        }

        *pcr_policy = super_pcr_policy_digest;
        return 0;
}

int tpm2_policy_super_pcr(
                Tpm2Context *c,
                const Tpm2Handle *session,
                const Tpm2PCRPrediction *prediction,
                uint16_t algorithm) {

        int r;

        assert_se(c);
        assert_se(session);
        assert_se(prediction);

        TPM2B_DIGEST previous_policy_digest = TPM2B_DIGEST_MAKE(NULL, TPM2_SHA256_DIGEST_SIZE);

        uint32_t single_value_pcrs = 0;

        /* Look for all PCRs that have only a singled allowed hash value, and synthesize a single PolicyPCR policy item for them */
        for (uint32_t pcr = 0; pcr < TPM2_PCRS_MAX; pcr++) {
                if (!FLAGS_SET(prediction->pcrs, UINT32_C(1) << pcr))
                        continue;

                if (ordered_set_size(prediction->results[pcr]) != 1)
                        continue;

                log_debug("Including PCR %" PRIu32 " in single value PolicyPCR expression", pcr);

                single_value_pcrs |= UINT32_C(1) << pcr;
        }

        if (single_value_pcrs != 0) {
                TPML_PCR_SELECTION pcr_selection;
                tpm2_tpml_pcr_selection_from_mask(single_value_pcrs, algorithm, &pcr_selection);

                _cleanup_free_ TPM2B_DIGEST *current_policy_digest = NULL;
                r = tpm2_policy_pcr(
                                c,
                                session,
                                &pcr_selection,
                                &current_policy_digest);
                if (r < 0)
                        return r;

                previous_policy_digest = *current_policy_digest;
        }

        for (uint32_t pcr = 0; pcr < TPM2_PCRS_MAX; pcr++) {
                size_t n_branches;

                if (!FLAGS_SET(prediction->pcrs, UINT32_C(1) << pcr))
                        continue;

                n_branches = ordered_set_size(prediction->results[pcr]);
                if (n_branches < 1 || n_branches > 8)
                        return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Number of variants per PCR not in range 1…8");

                if (n_branches == 1) /* Single choice PCRs are already covered by the loop above */
                        continue;

                log_debug("Submitting PCR/OR policy for PCR %" PRIu32, pcr);

                TPML_PCR_SELECTION pcr_selection;
                tpm2_tpml_pcr_selection_from_mask(UINT32_C(1) << pcr, algorithm, &pcr_selection);

                _cleanup_free_ TPM2B_DIGEST *current_policy_digest = NULL;
                r = tpm2_policy_pcr(
                                c,
                                session,
                                &pcr_selection,
                                &current_policy_digest);
                if (r < 0)
                        return r;

                _cleanup_free_ TPM2B_DIGEST *branches = NULL;
                branches = new0(TPM2B_DIGEST, n_branches);
                if (!branches)
                        return log_oom();

                Tpm2PCRPredictionResult *banks;
                size_t i = 0;
                ORDERED_SET_FOREACH(banks, prediction->results[pcr]) {
                        TPM2B_DIGEST pcr_policy_digest = previous_policy_digest;

                        TPM2B_DIGEST *hash = tpm2_pcr_prediction_result_get_hash(banks, algorithm);
                        if (!hash)
                                continue;

                        /* Evolve it based on the expected PCR value for this PCR */
                        r = tpm2_calculate_policy_pcr(
                                        &TPM2_PCR_VALUE_MAKE(
                                                        pcr,
                                                        algorithm,
                                                        *hash),
                                        /* n_pcr_values= */ 1,
                                        &pcr_policy_digest);
                        if (r < 0)
                                return r;

                        branches[i++] = pcr_policy_digest;
                }

                assert_se(i == n_branches);

                current_policy_digest = mfree(current_policy_digest);
                r = tpm2_policy_or(
                                c,
                                session,
                                branches,
                                n_branches,
                                &current_policy_digest);
                if (r < 0)
                        return r;

                previous_policy_digest = *current_policy_digest;
        }

        return 0;
}

void tpm2_pcrlock_policy_done(Tpm2PCRLockPolicy *data) {
        assert(data);

        data->prediction_json = json_variant_unref(data->prediction_json);
        tpm2_pcr_prediction_done(&data->prediction);
        iovec_done(&data->nv_handle);
        iovec_done(&data->nv_public);
        iovec_done(&data->srk_handle);
        iovec_done(&data->pin_public);
        iovec_done(&data->pin_private);
}

static int json_dispatch_tpm2_algorithm(const char *name, JsonVariant *variant, JsonDispatchFlags flags, void *userdata) {
        uint16_t *algorithm = ASSERT_PTR(userdata);
        int r;

        r = tpm2_hash_alg_from_string(json_variant_string(variant));
        if (r < 0 || tpm2_hash_algorithm_index(r) == SIZE_MAX)
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Invalid hash algorithm: %s", json_variant_string(variant));

        *algorithm = r;
        return 0;
}

int tpm2_pcrlock_search_file(const char *path, FILE **ret_file, char **ret_path) {
        static const char search[] =
                "/run/systemd\0"
                "/var/lib/systemd\0";

        int r;

        if (!path)
                path = "pcrlock.json";

        r = search_and_fopen_nulstr(path, ret_file ? "re" : NULL, NULL, search, ret_file, ret_path);
        if (r < 0)
                return log_debug_errno(r, "Failed to find TPM2 pcrlock policy file '%s': %m", path);

        return 0;
}

int tpm2_pcrlock_policy_from_json(
                JsonVariant *v,
                Tpm2PCRLockPolicy *ret_policy) {

        /* We use a type check of _JSON_VARIANT_TYPE_INVALID for the integer fields to allow
         * json_dispatch_uint32() to parse strings as integers to work around the integer type weakness of
         * JSON's design. */
        JsonDispatch policy_dispatch[] = {
                { "pcrBank",    JSON_VARIANT_STRING,        json_dispatch_tpm2_algorithm, offsetof(Tpm2PCRLockPolicy, algorithm),       JSON_MANDATORY },
                { "pcrValues",  JSON_VARIANT_ARRAY,         json_dispatch_variant,        offsetof(Tpm2PCRLockPolicy, prediction_json), JSON_MANDATORY },
                { "nvIndex",    _JSON_VARIANT_TYPE_INVALID, json_dispatch_uint32,         offsetof(Tpm2PCRLockPolicy, nv_index),        JSON_MANDATORY },
                { "nvHandle",   JSON_VARIANT_STRING,        json_dispatch_unbase64_iovec, offsetof(Tpm2PCRLockPolicy, nv_handle),       JSON_MANDATORY },
                { "nvPublic",   JSON_VARIANT_STRING,        json_dispatch_unbase64_iovec, offsetof(Tpm2PCRLockPolicy, nv_public),       JSON_MANDATORY },
                { "srkHandle",  JSON_VARIANT_STRING,        json_dispatch_unbase64_iovec, offsetof(Tpm2PCRLockPolicy, srk_handle),      JSON_MANDATORY },
                { "pinPublic",  JSON_VARIANT_STRING,        json_dispatch_unbase64_iovec, offsetof(Tpm2PCRLockPolicy, pin_public),      JSON_MANDATORY },
                { "pinPrivate", JSON_VARIANT_STRING,        json_dispatch_unbase64_iovec, offsetof(Tpm2PCRLockPolicy, pin_private),     JSON_MANDATORY },
                {}
        };

        _cleanup_(tpm2_pcrlock_policy_done) Tpm2PCRLockPolicy policy = {};
        int r;

        assert(v);
        assert(ret_policy);

        r = json_dispatch(v, policy_dispatch, JSON_LOG, &policy);
        if (r < 0)
                return r;

        r = tpm2_pcr_prediction_from_json(&policy.prediction, policy.algorithm, policy.prediction_json);
        if (r < 0)
                return r;

        *ret_policy = TAKE_STRUCT(policy);
        return 1;
}

int tpm2_pcrlock_policy_load(
                const char *path,
                Tpm2PCRLockPolicy *ret_policy) {

        _cleanup_free_ char *discovered_path = NULL;
        _cleanup_fclose_ FILE *f = NULL;
        int r;

        r = tpm2_pcrlock_search_file(path, &f, &discovered_path);
        if (r == -ENOENT) {
                *ret_policy = (Tpm2PCRLockPolicy) {};
                return 0;
        }
        if (r < 0)
                return log_error_errno(r, "Failed to load TPM2 pcrlock policy file: %m");

        _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
        r = json_parse_file(
                        f,
                        discovered_path,
                        /* flags = */ 0,
                        &v,
                        /* ret_line= */ NULL,
                        /* ret_column= */ NULL);
        if (r < 0)
                return log_error_errno(r, "Failed to parse existing pcrlock policy file '%s': %m", discovered_path);

        return tpm2_pcrlock_policy_from_json(v, ret_policy);
}

static int pcrlock_policy_load_credential(
                const char *name,
                const struct iovec *data,
                Tpm2PCRLockPolicy *ret) {

        _cleanup_free_ char *c = NULL;
        int r;

        assert(name);

        c = strdup(name);
        if (!c)
                return log_oom();

        ascii_strlower(c); /* Lowercase, to match what we did at encryption time */

        _cleanup_(iovec_done) struct iovec decoded = {};
        r = decrypt_credential_and_warn(
                        c,
                        now(CLOCK_REALTIME),
                        /* tpm2_device= */ NULL,
                        /* tpm2_signature_path= */ NULL,
                        UID_INVALID,
                        data,
                        CREDENTIAL_ALLOW_NULL,
                        &decoded);
        if (r < 0)
                return r;

        if (memchr(decoded.iov_base, 0, decoded.iov_len))
                return log_error_errno(r, "Credential '%s' contains embedded NUL byte, refusing.", name);

        _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
        r = json_parse(decoded.iov_base,
                       /* flags= */ 0,
                       &v,
                       /* ret_line= */ NULL,
                       /* ret_column= */ NULL);
        if (r < 0)
                return log_error_errno(r, "Failed to parse pcrlock policy: %m");

        r = tpm2_pcrlock_policy_from_json(v, ret);
        if (r < 0)
                return r;

        return 0;
}

int tpm2_pcrlock_policy_from_credentials(
                const struct iovec *srk,
                const struct iovec *nv,
                Tpm2PCRLockPolicy *ret) {

        _cleanup_close_ int dfd = -EBADF;
        int r;

        /* During boot we'll not have access to the pcrlock.json file in /var/. In order to support
         * pcrlock-bound root file systems we'll store a copy of the JSON data, wrapped in an (plaintext)
         * credential in the ESP or XBOOTLDR partition. There might be multiple of those however (because of
         * multi-boot), hence we use the SRK and NV data from the LUKS2 header as search key, and parse all
         * such JSON policies until we find a matching one. */

        const char *cp = secure_getenv("SYSTEMD_ENCRYPTED_SYSTEM_CREDENTIALS_DIRECTORY") ?: ENCRYPTED_SYSTEM_CREDENTIALS_DIRECTORY;

        dfd = open(cp, O_CLOEXEC|O_DIRECTORY);
        if (dfd < 0) {
                if (errno == ENOENT) {
                        log_debug("No encrypted system credentials passed.");
                        return 0;
                }

                return log_error_errno(errno, "Failed to open system credentials directory.");
        }

        _cleanup_free_ DirectoryEntries *de = NULL;
        r = readdir_all(dfd, RECURSE_DIR_IGNORE_DOT, &de);
        if (r < 0)
                return log_error_errno(r, "Failed to enumerate system credentials: %m");

        FOREACH_ARRAY(i, de->entries, de->n_entries) {
                _cleanup_(iovec_done) struct iovec data = {};
                struct dirent *d = *i;

                if (!startswith_no_case(d->d_name, "pcrlock.")) /* VFAT is case-insensitive, hence don't be too strict here */
                        continue;

                r = read_full_file_full(
                                dfd, d->d_name,
                                /* offset= */ UINT64_MAX,
                                /* size= */ CREDENTIAL_ENCRYPTED_SIZE_MAX,
                                READ_FULL_FILE_UNBASE64|READ_FULL_FILE_FAIL_WHEN_LARGER,
                                /* bind_name= */ NULL,
                                (char**) &data.iov_base,
                                &data.iov_len);
                if (r == -ENOENT)
                        continue;
                if (r < 0) {
                        log_warning_errno(r, "Failed to read credentials file %s/%s, skipping: %m", ENCRYPTED_SYSTEM_CREDENTIALS_DIRECTORY, d->d_name);
                        continue;
                }

                _cleanup_(tpm2_pcrlock_policy_done) Tpm2PCRLockPolicy loaded_policy = {};
                r = pcrlock_policy_load_credential(
                                d->d_name,
                                &data,
                                &loaded_policy);
                if (r < 0) {
                        log_warning_errno(r, "Loading of pcrlock policy from credential '%s/%s' failed, skipping.", ENCRYPTED_SYSTEM_CREDENTIALS_DIRECTORY, d->d_name);
                        continue;
                }

                if ((!srk || iovec_memcmp(srk, &loaded_policy.srk_handle) == 0) &&
                    (!nv || iovec_memcmp(nv, &loaded_policy.nv_handle) == 0)) {
                        *ret = TAKE_STRUCT(loaded_policy);
                        return 1;
                }
        }

        log_info("No pcrlock policy found among system credentials.");
        *ret = (Tpm2PCRLockPolicy) {};
        return 0;
}

int tpm2_load_public_key_file(const char *path, TPM2B_PUBLIC *ret) {
        _cleanup_free_ char *device_key_buffer = NULL;
        TPM2B_PUBLIC device_key_public = {};
        size_t device_key_buffer_size;
        TSS2_RC rc;
        int r;

        assert(path);
        assert(ret);

        r = dlopen_tpm2();
        if (r < 0)
                return log_debug_errno(r, "TPM2 support not installed: %m");

        r = read_full_file(path, &device_key_buffer, &device_key_buffer_size);
        if (r < 0)
                return log_error_errno(r, "Failed to read device key from file '%s': %m", path);

        size_t offset = 0;
        rc = sym_Tss2_MU_TPM2B_PUBLIC_Unmarshal(
                        (uint8_t*) device_key_buffer,
                        device_key_buffer_size,
                        &offset,
                        &device_key_public);
        if (rc != TSS2_RC_SUCCESS)
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "Could not unmarshal public key from file.");

        assert(offset <= device_key_buffer_size);
        if (offset != device_key_buffer_size)
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "Found %zu bytes of trailing garbage in public key file.",
                                       device_key_buffer_size - offset);

        *ret = device_key_public;
        return 0;
}

int tpm2_hmac_key_from_pin(Tpm2Context *c, const Tpm2Handle *session, const TPM2B_AUTH *pin, Tpm2Handle **ret) {
        int r;

        assert(c);
        assert(pin);
        assert(ret);

        log_debug("Converting PIN into TPM2 HMAC-SHA256 object.");

        /* Load the PIN (which we have stored in the "auth" TPM2B_AUTH) into the TPM as an HMAC key so that
         * we can use it in a TPM2_PolicySigned() to write to the nvindex. For that we'll prep a pair of
         * TPM2B_PUBLIC and TPM2B_SENSITIVE that defines an HMAC-SHA256 keyed hash function, and initialize
         * it based on the provided PIN data. */

        TPM2B_PUBLIC auth_hmac_public = {
                .publicArea = {
                        .type = TPM2_ALG_KEYEDHASH,
                        .nameAlg = TPM2_ALG_SHA256,
                        .objectAttributes = TPMA_OBJECT_SIGN_ENCRYPT,
                        .parameters.keyedHashDetail.scheme = {
                                .scheme = TPM2_ALG_HMAC,
                                .details.hmac.hashAlg = TPM2_ALG_SHA256,
                        },
                        .unique.keyedHash.size = SHA256_DIGEST_SIZE,
                },
        };

        TPM2B_SENSITIVE auth_hmac_private = {
                .sensitiveArea = {
                        .sensitiveType = TPM2_ALG_KEYEDHASH,
                        .sensitive.bits.size = pin->size,
                        .seedValue.size = SHA256_DIGEST_SIZE,
                },
        };

        /* Copy in the key data */
        memcpy_safe(auth_hmac_private.sensitiveArea.sensitive.bits.buffer, pin->buffer, pin->size);

        /* NB: We initialize the seed of the TPMT_SENSITIVE structure to all zeroes, since we want a stable
         * "name" of the PIN object */

        /* Now calculate the "unique" field for the public area, based on the sensitive data, according to
         * the algorithm in the TPM2 spec, part 1, Section 27.5.3.2 */
        struct iovec sensitive_data[] = {
                IOVEC_MAKE(auth_hmac_private.sensitiveArea.seedValue.buffer, auth_hmac_private.sensitiveArea.seedValue.size),
                IOVEC_MAKE(auth_hmac_private.sensitiveArea.sensitive.bits.buffer, auth_hmac_private.sensitiveArea.sensitive.bits.size),
        };
        r = tpm2_digest_many(
                        auth_hmac_public.publicArea.nameAlg,
                        &auth_hmac_public.publicArea.unique.keyedHash,
                        sensitive_data,
                        ELEMENTSOF(sensitive_data),
                        /* extend= */ false);
        if (r < 0)
                return r;

        /* And now load the public/private parts into the TPM and get a handle back */
        r = tpm2_load_external(
                        c,
                        session,
                        &auth_hmac_public,
                        &auth_hmac_private,
                        ret);
        if (r < 0)
                return log_error_errno(r, "Failed to load PIN into TPM2: %m");

        return 0;
}
#endif

char *tpm2_pcr_mask_to_string(uint32_t mask) {
        _cleanup_free_ char *s = NULL;

        FOREACH_PCR_IN_MASK(n, mask)
                if (strextendf_with_separator(&s, "+", "%d", n) < 0)
                        return NULL;

        if (!s)
                return strdup("");

        return TAKE_PTR(s);
}

int tpm2_make_pcr_json_array(uint32_t pcr_mask, JsonVariant **ret) {
        _cleanup_(json_variant_unrefp) JsonVariant *a = NULL;
        int r;

        assert(ret);

        for (size_t i = 0; i < TPM2_PCRS_MAX; i++) {
                _cleanup_(json_variant_unrefp) JsonVariant *e = NULL;

                if ((pcr_mask & (UINT32_C(1) << i)) == 0)
                        continue;

                r = json_variant_new_integer(&e, i);
                if (r < 0)
                        return r;

                r = json_variant_append_array(&a, e);
                if (r < 0)
                        return r;
        }

        if (!a)
                return json_variant_new_array(ret, NULL, 0);

        *ret = TAKE_PTR(a);
        return 0;
}

int tpm2_parse_pcr_json_array(JsonVariant *v, uint32_t *ret) {
        JsonVariant *e;
        uint32_t mask = 0;

        if (!json_variant_is_array(v))
                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "TPM2 PCR array is not a JSON array.");

        JSON_VARIANT_ARRAY_FOREACH(e, v) {
                uint64_t u;

                if (!json_variant_is_unsigned(e))
                        return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "TPM2 PCR is not an unsigned integer.");

                u = json_variant_unsigned(e);
                if (u >= TPM2_PCRS_MAX)
                        return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "TPM2 PCR number out of range: %" PRIu64, u);

                mask |= UINT32_C(1) << u;
        }

        if (ret)
                *ret = mask;

        return 0;
}

int tpm2_make_luks2_json(
                int keyslot,
                uint32_t hash_pcr_mask,
                uint16_t pcr_bank,
                const struct iovec *pubkey,
                uint32_t pubkey_pcr_mask,
                uint16_t primary_alg,
                const struct iovec *blob,
                const struct iovec *policy_hash,
                const struct iovec *salt,
                const struct iovec *srk,
                const struct iovec *pcrlock_nv,
                TPM2Flags flags,
                JsonVariant **ret) {

        _cleanup_(json_variant_unrefp) JsonVariant *v = NULL, *hmj = NULL, *pkmj = NULL;
        _cleanup_free_ char *keyslot_as_string = NULL;
        int r;

        assert(iovec_is_valid(pubkey));
        assert(iovec_is_valid(blob));
        assert(iovec_is_valid(policy_hash));

        if (asprintf(&keyslot_as_string, "%i", keyslot) < 0)
                return -ENOMEM;

        r = tpm2_make_pcr_json_array(hash_pcr_mask, &hmj);
        if (r < 0)
                return r;

        if (pubkey_pcr_mask != 0) {
                r = tpm2_make_pcr_json_array(pubkey_pcr_mask, &pkmj);
                if (r < 0)
                        return r;
        }

        /* Note: We made the mistake of using "-" in the field names, which isn't particular compatible with
         * other programming languages. Let's not make things worse though, i.e. future additions to the JSON
         * object should use "_" rather than "-" in field names. */

        r = json_build(&v,
                       JSON_BUILD_OBJECT(
                                       JSON_BUILD_PAIR("type", JSON_BUILD_CONST_STRING("systemd-tpm2")),
                                       JSON_BUILD_PAIR("keyslots", JSON_BUILD_ARRAY(JSON_BUILD_STRING(keyslot_as_string))),
                                       JSON_BUILD_PAIR("tpm2-blob", JSON_BUILD_IOVEC_BASE64(blob)),
                                       JSON_BUILD_PAIR("tpm2-pcrs", JSON_BUILD_VARIANT(hmj)),
                                       JSON_BUILD_PAIR_CONDITION(pcr_bank != 0 && tpm2_hash_alg_to_string(pcr_bank), "tpm2-pcr-bank", JSON_BUILD_STRING(tpm2_hash_alg_to_string(pcr_bank))),
                                       JSON_BUILD_PAIR_CONDITION(primary_alg != 0 && tpm2_asym_alg_to_string(primary_alg), "tpm2-primary-alg", JSON_BUILD_STRING(tpm2_asym_alg_to_string(primary_alg))),
                                       JSON_BUILD_PAIR("tpm2-policy-hash", JSON_BUILD_IOVEC_HEX(policy_hash)),
                                       JSON_BUILD_PAIR("tpm2-pin", JSON_BUILD_BOOLEAN(flags & TPM2_FLAGS_USE_PIN)),
                                       JSON_BUILD_PAIR("tpm2_pcrlock", JSON_BUILD_BOOLEAN(flags & TPM2_FLAGS_USE_PCRLOCK)),
                                       JSON_BUILD_PAIR_CONDITION(pubkey_pcr_mask != 0, "tpm2_pubkey_pcrs", JSON_BUILD_VARIANT(pkmj)),
                                       JSON_BUILD_PAIR_CONDITION(iovec_is_set(pubkey), "tpm2_pubkey", JSON_BUILD_IOVEC_BASE64(pubkey)),
                                       JSON_BUILD_PAIR_CONDITION(iovec_is_set(salt), "tpm2_salt", JSON_BUILD_IOVEC_BASE64(salt)),
                                       JSON_BUILD_PAIR_CONDITION(iovec_is_set(srk), "tpm2_srk", JSON_BUILD_IOVEC_BASE64(srk)),
                                       JSON_BUILD_PAIR_CONDITION(iovec_is_set(pcrlock_nv), "tpm2_pcrlock_nv", JSON_BUILD_IOVEC_BASE64(pcrlock_nv))));
        if (r < 0)
                return r;

        if (ret)
                *ret = TAKE_PTR(v);

        return keyslot;
}

int tpm2_parse_luks2_json(
                JsonVariant *v,
                int *ret_keyslot,
                uint32_t *ret_hash_pcr_mask,
                uint16_t *ret_pcr_bank,
                struct iovec *ret_pubkey,
                uint32_t *ret_pubkey_pcr_mask,
                uint16_t *ret_primary_alg,
                struct iovec *ret_blob,
                struct iovec *ret_policy_hash,
                struct iovec *ret_salt,
                struct iovec *ret_srk,
                struct iovec *ret_pcrlock_nv,
                TPM2Flags *ret_flags) {

        _cleanup_(iovec_done) struct iovec blob = {}, policy_hash = {}, pubkey = {}, salt = {}, srk = {}, pcrlock_nv = {};
        uint32_t hash_pcr_mask = 0, pubkey_pcr_mask = 0;
        uint16_t primary_alg = TPM2_ALG_ECC; /* ECC was the only supported algorithm in systemd < 250, use that as implied default, for compatibility */
        uint16_t pcr_bank = UINT16_MAX; /* default: pick automatically */
        int r, keyslot = -1;
        TPM2Flags flags = 0;
        JsonVariant *w;

        assert(v);

        if (ret_keyslot) {
                keyslot = cryptsetup_get_keyslot_from_token(v);
                if (keyslot < 0) {
                        /* Return a recognizable error when parsing this field, so that callers can handle parsing
                         * errors of the keyslots field gracefully, since it's not 'owned' by us, but by the LUKS2
                         * spec */
                        log_debug_errno(keyslot, "Failed to extract keyslot index from TPM2 JSON data token, skipping: %m");
                        return -EUCLEAN;
                }
        }

        w = json_variant_by_key(v, "tpm2-pcrs");
        if (!w)
                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "TPM2 token data lacks 'tpm2-pcrs' field.");

        r = tpm2_parse_pcr_json_array(w, &hash_pcr_mask);
        if (r < 0)
                return log_debug_errno(r, "Failed to parse TPM2 PCR mask: %m");

        /* The bank field is optional, since it was added in systemd 250 only. Before the bank was hardcoded
         * to SHA256. */
        w = json_variant_by_key(v, "tpm2-pcr-bank");
        if (w) {
                /* The PCR bank field is optional */

                if (!json_variant_is_string(w))
                        return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "TPM2 PCR bank is not a string.");

                r = tpm2_hash_alg_from_string(json_variant_string(w));
                if (r < 0)
                        return log_debug_errno(r, "TPM2 PCR bank invalid or not supported: %s", json_variant_string(w));

                pcr_bank = r;
        }

        /* The primary key algorithm field is optional, since it was also added in systemd 250 only. Before
         * the algorithm was hardcoded to ECC. */
        w = json_variant_by_key(v, "tpm2-primary-alg");
        if (w) {
                /* The primary key algorithm is optional */

                if (!json_variant_is_string(w))
                        return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "TPM2 primary key algorithm is not a string.");

                r = tpm2_asym_alg_from_string(json_variant_string(w));
                if (r < 0)
                        return log_debug_errno(r, "TPM2 asymmetric algorithm invalid or not supported: %s", json_variant_string(w));

                primary_alg = r;
        }

        w = json_variant_by_key(v, "tpm2-blob");
        if (!w)
                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "TPM2 token data lacks 'tpm2-blob' field.");

        r = json_variant_unbase64_iovec(w, &blob);
        if (r < 0)
                return log_debug_errno(r, "Invalid base64 data in 'tpm2-blob' field.");

        w = json_variant_by_key(v, "tpm2-policy-hash");
        if (!w)
                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "TPM2 token data lacks 'tpm2-policy-hash' field.");

        r = json_variant_unhex_iovec(w, &policy_hash);
        if (r < 0)
                return log_debug_errno(r, "Invalid base64 data in 'tpm2-policy-hash' field.");

        w = json_variant_by_key(v, "tpm2-pin");
        if (w) {
                if (!json_variant_is_boolean(w))
                        return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "TPM2 PIN policy is not a boolean.");

                SET_FLAG(flags, TPM2_FLAGS_USE_PIN, json_variant_boolean(w));
        }

        w = json_variant_by_key(v, "tpm2_pcrlock");
        if (w) {
                if (!json_variant_is_boolean(w))
                        return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "TPM2 pclock policy is not a boolean.");

                SET_FLAG(flags, TPM2_FLAGS_USE_PCRLOCK, json_variant_boolean(w));
        }

        w = json_variant_by_key(v, "tpm2_salt");
        if (w) {
                r = json_variant_unbase64_iovec(w, &salt);
                if (r < 0)
                        return log_debug_errno(r, "Invalid base64 data in 'tpm2_salt' field.");
        }

        w = json_variant_by_key(v, "tpm2_pubkey_pcrs");
        if (w) {
                r = tpm2_parse_pcr_json_array(w, &pubkey_pcr_mask);
                if (r < 0)
                        return r;
        }

        w = json_variant_by_key(v, "tpm2_pubkey");
        if (w) {
                r = json_variant_unbase64_iovec(w, &pubkey);
                if (r < 0)
                        return log_debug_errno(r, "Failed to decode PCR public key.");
        } else if (pubkey_pcr_mask != 0)
                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Public key PCR mask set, but not public key included in JSON data, refusing.");

        w = json_variant_by_key(v, "tpm2_srk");
        if (w) {
                r = json_variant_unbase64_iovec(w, &srk);
                if (r < 0)
                        return log_debug_errno(r, "Invalid base64 data in 'tpm2_srk' field.");
        }

        w = json_variant_by_key(v, "tpm2_pcrlock_nv");
        if (w) {
                r = json_variant_unbase64_iovec(w, &pcrlock_nv);
                if (r < 0)
                        return log_debug_errno(r, "Invalid base64 data in 'tpm2_pcrlock_nv' field.");
        }

        if (ret_keyslot)
                *ret_keyslot = keyslot;
        if (ret_hash_pcr_mask)
                *ret_hash_pcr_mask = hash_pcr_mask;
        if (ret_pcr_bank)
                *ret_pcr_bank = pcr_bank;
        if (ret_pubkey)
                *ret_pubkey = TAKE_STRUCT(pubkey);
        if (ret_pubkey_pcr_mask)
                *ret_pubkey_pcr_mask = pubkey_pcr_mask;
        if (ret_primary_alg)
                *ret_primary_alg = primary_alg;
        if (ret_blob)
                *ret_blob = TAKE_STRUCT(blob);
        if (ret_policy_hash)
                *ret_policy_hash = TAKE_STRUCT(policy_hash);
        if (ret_salt)
                *ret_salt = TAKE_STRUCT(salt);
        if (ret_srk)
                *ret_srk = TAKE_STRUCT(srk);
        if (ret_pcrlock_nv)
                *ret_pcrlock_nv = TAKE_STRUCT(pcrlock_nv);
        if (ret_flags)
                *ret_flags = flags;
        return 0;
}

int tpm2_hash_alg_to_size(uint16_t alg) {
        switch (alg) {
        case TPM2_ALG_SHA1:
                return 20;
        case TPM2_ALG_SHA256:
                return 32;
        case TPM2_ALG_SHA384:
                return 48;
        case TPM2_ALG_SHA512:
                return 64;
        default:
                return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown hash algorithm id 0x%" PRIx16, alg);
        }
}

const char *tpm2_hash_alg_to_string(uint16_t alg) {
        switch (alg) {
        case TPM2_ALG_SHA1:
                return "sha1";
        case TPM2_ALG_SHA256:
                return "sha256";
        case TPM2_ALG_SHA384:
                return "sha384";
        case TPM2_ALG_SHA512:
                return "sha512";
        default:
                log_debug("Unknown hash algorithm id 0x%" PRIx16, alg);
                return NULL;
        }
}

int tpm2_hash_alg_from_string(const char *alg) {
        if (strcaseeq_ptr(alg, "sha1"))
                return TPM2_ALG_SHA1;
        if (strcaseeq_ptr(alg, "sha256"))
                return TPM2_ALG_SHA256;
        if (strcaseeq_ptr(alg, "sha384"))
                return TPM2_ALG_SHA384;
        if (strcaseeq_ptr(alg, "sha512"))
                return TPM2_ALG_SHA512;
        return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown hash algorithm name '%s'", alg);
}

const char *tpm2_asym_alg_to_string(uint16_t alg) {
        switch (alg) {
        case TPM2_ALG_ECC:
                return "ecc";
        case TPM2_ALG_RSA:
                return "rsa";
        default:
                log_debug("Unknown asymmetric algorithm id 0x%" PRIx16, alg);
                return NULL;
        }
}

int tpm2_asym_alg_from_string(const char *alg) {
        if (strcaseeq_ptr(alg, "ecc"))
                return TPM2_ALG_ECC;
        if (strcaseeq_ptr(alg, "rsa"))
                return TPM2_ALG_RSA;
        return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown asymmetric algorithm name '%s'", alg);
}

const char *tpm2_sym_alg_to_string(uint16_t alg) {
        switch (alg) {
#if HAVE_TPM2
        case TPM2_ALG_AES:
                return "aes";
#endif
        default:
                log_debug("Unknown symmetric algorithm id 0x%" PRIx16, alg);
                return NULL;
        }
}

int tpm2_sym_alg_from_string(const char *alg) {
#if HAVE_TPM2
        if (strcaseeq_ptr(alg, "aes"))
                return TPM2_ALG_AES;
#endif
        return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown symmetric algorithm name '%s'", alg);
}

const char *tpm2_sym_mode_to_string(uint16_t mode) {
        switch (mode) {
#if HAVE_TPM2
        case TPM2_ALG_CTR:
                return "ctr";
        case TPM2_ALG_OFB:
                return "ofb";
        case TPM2_ALG_CBC:
                return "cbc";
        case TPM2_ALG_CFB:
                return "cfb";
        case TPM2_ALG_ECB:
                return "ecb";
#endif
        default:
                log_debug("Unknown symmetric mode id 0x%" PRIx16, mode);
                return NULL;
        }
}

int tpm2_sym_mode_from_string(const char *mode) {
#if HAVE_TPM2
        if (strcaseeq_ptr(mode, "ctr"))
                return TPM2_ALG_CTR;
        if (strcaseeq_ptr(mode, "ofb"))
                return TPM2_ALG_OFB;
        if (strcaseeq_ptr(mode, "cbc"))
                return TPM2_ALG_CBC;
        if (strcaseeq_ptr(mode, "cfb"))
                return TPM2_ALG_CFB;
        if (strcaseeq_ptr(mode, "ecb"))
                return TPM2_ALG_ECB;
#endif
        return log_debug_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown symmetric mode name '%s'", mode);
}

Tpm2Support tpm2_support(void) {
        Tpm2Support support = TPM2_SUPPORT_NONE;
        int r;

        if (detect_container() <= 0) {
                /* Check if there's a /dev/tpmrm* device via sysfs. If we run in a container we likely just
                 * got the host sysfs mounted. Since devices are generally not virtualized for containers,
                 * let's assume containers never have a TPM, at least for now. */

                r = dir_is_empty("/sys/class/tpmrm", /* ignore_hidden_or_backup= */ false);
                if (r < 0) {
                        if (r != -ENOENT)
                                log_debug_errno(r, "Unable to test whether /sys/class/tpmrm/ exists and is populated, assuming it is not: %m");
                } else if (r == 0) /* populated! */
                        support |= TPM2_SUPPORT_SUBSYSTEM|TPM2_SUPPORT_DRIVER;
                else
                        /* If the directory exists but is empty, we know the subsystem is enabled but no
                         * driver has been loaded yet. */
                        support |= TPM2_SUPPORT_SUBSYSTEM;
        }

        if (efi_has_tpm2())
                support |= TPM2_SUPPORT_FIRMWARE;

#if HAVE_TPM2
        support |= TPM2_SUPPORT_SYSTEM;

        r = dlopen_tpm2();
        if (r >= 0)
                support |= TPM2_SUPPORT_LIBRARIES;
#endif

        return support;
}

#if HAVE_TPM2
static void tpm2_pcr_values_apply_default_hash_alg(Tpm2PCRValue *pcr_values, size_t n_pcr_values) {
        TPMI_ALG_HASH default_hash = 0;
        FOREACH_ARRAY(v, pcr_values, n_pcr_values)
                if (v->hash != 0) {
                        default_hash = v->hash;
                        break;
                }

        if (default_hash != 0)
                FOREACH_ARRAY(v, pcr_values, n_pcr_values)
                        if (v->hash == 0)
                                v->hash = default_hash;
}
#endif

/* The following tpm2_parse_pcr_argument*() functions all log errors, to match the behavior of system-wide
 * parse_*_argument() functions. */

/* Parse the PCR selection/value arg(s) and return a corresponding array of Tpm2PCRValue objects.
 *
 * The format is the same as tpm2_pcr_values_from_string(). The first provided entry with a hash algorithm
 * set will be used as the 'default' hash algorithm. All entries with an unset hash algorithm will be updated
 * with the 'default' hash algorithm. The resulting array will be sorted and checked for validity.
 *
 * This will replace *ret_pcr_values with the new array of pcr values; to append to an existing array, use
 * tpm2_parse_pcr_argument_append(). */
int tpm2_parse_pcr_argument(const char *arg, Tpm2PCRValue **ret_pcr_values, size_t *ret_n_pcr_values) {
#if HAVE_TPM2
        int r;

        assert(arg);
        assert(ret_pcr_values);
        assert(ret_n_pcr_values);

        _cleanup_free_ Tpm2PCRValue *pcr_values = NULL;
        size_t n_pcr_values = 0;
        r = tpm2_pcr_values_from_string(arg, &pcr_values, &n_pcr_values);
        if (r < 0)
                return log_error_errno(r, "Could not parse PCR values from '%s': %m", arg);

        tpm2_pcr_values_apply_default_hash_alg(pcr_values, n_pcr_values);

        tpm2_sort_pcr_values(pcr_values, n_pcr_values);

        if (!tpm2_pcr_values_valid(pcr_values, n_pcr_values))
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Parsed PCR values are not valid.");

        *ret_pcr_values = TAKE_PTR(pcr_values);
        *ret_n_pcr_values = n_pcr_values;

        return 0;
#else
        return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "TPM2 support is disabled.");
#endif
}

/* Same as tpm2_parse_pcr_argument(), but the pcr values array is appended to. If the provided pcr values
 * array is not NULL, it must point to an allocated pcr values array and the provided number of pcr values
 * must be correct.
 *
 * Note that 'arg' is parsed into a new array of pcr values independently of any previous pcr values,
 * including application of the default hash algorithm. Then the two arrays are combined, the default hash
 * algorithm check applied again (in case either the previous or current array had no default hash
 * algorithm), and then the resulting array is sorted and rechecked for validity. */
int tpm2_parse_pcr_argument_append(const char *arg, Tpm2PCRValue **pcr_values, size_t *n_pcr_values) {
#if HAVE_TPM2
        int r;

        assert(arg);
        assert(pcr_values);
        assert(n_pcr_values);

        _cleanup_free_ Tpm2PCRValue *more_pcr_values = NULL;
        size_t n_more_pcr_values;
        r = tpm2_parse_pcr_argument(arg, &more_pcr_values, &n_more_pcr_values);
        if (r < 0)
                return r;

        /* If we got previous values, append them. */
        if (*pcr_values && !GREEDY_REALLOC_APPEND(more_pcr_values, n_more_pcr_values, *pcr_values, *n_pcr_values))
                return log_oom();

        tpm2_pcr_values_apply_default_hash_alg(more_pcr_values, n_more_pcr_values);

        tpm2_sort_pcr_values(more_pcr_values, n_more_pcr_values);

        if (!tpm2_pcr_values_valid(more_pcr_values, n_more_pcr_values))
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Parsed PCR values are not valid.");

        SWAP_TWO(*pcr_values, more_pcr_values);
        *n_pcr_values = n_more_pcr_values;

        return 0;
#else
        return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "TPM2 support is disabled.");
#endif
}

/* Same as tpm2_parse_pcr_argument() but converts the pcr values to a pcr mask. If more than one hash
 * algorithm is included in the pcr values array this results in error. This retains the previous behavior of
 * tpm2_parse_pcr_argument() of clearing the mask if 'arg' is empty, replacing the mask if it is set to
 * UINT32_MAX, and or-ing the mask otherwise. */
int tpm2_parse_pcr_argument_to_mask(const char *arg, uint32_t *ret_mask) {
#if HAVE_TPM2
        _cleanup_free_ Tpm2PCRValue *pcr_values = NULL;
        size_t n_pcr_values;
        int r;

        assert(arg);
        assert(ret_mask);

        r = tpm2_parse_pcr_argument(arg, &pcr_values, &n_pcr_values);
        if (r < 0)
                return r;

        if (n_pcr_values == 0) {
                /* This retains the previous behavior of clearing the mask if the arg is empty */
                *ret_mask = 0;
                return 0;
        }

        size_t hash_count;
        r = tpm2_pcr_values_hash_count(pcr_values, n_pcr_values, &hash_count);
        if (r < 0)
                return log_error_errno(r, "Could not get hash count from pcr values: %m");

        if (hash_count > 1)
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Multiple PCR hash banks selected.");

        uint32_t new_mask;
        r = tpm2_pcr_values_to_mask(pcr_values, n_pcr_values, pcr_values[0].hash, &new_mask);
        if (r < 0)
                return log_error_errno(r, "Could not get pcr values mask: %m");

        if (*ret_mask == UINT32_MAX)
                *ret_mask = new_mask;
        else
                *ret_mask |= new_mask;

        return 0;
#else
        return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "TPM2 support is disabled.");
#endif
}

int tpm2_load_pcr_signature(const char *path, JsonVariant **ret) {
        _cleanup_strv_free_ char **search = NULL;
        _cleanup_free_ char *discovered_path = NULL;
        _cleanup_fclose_ FILE *f = NULL;
        int r;

        /* Tries to load a JSON PCR signature file. Takes an absolute path, a simple file name or NULL. In
         * the latter two cases searches in /etc/, /usr/lib/, /run/, as usual. */

        search = strv_new(CONF_PATHS("systemd"));
        if (!search)
                return log_oom_debug();

        if (!path) {
                /* If no path is specified, then look for "tpm2-pcr-signature.json" automatically. Also, in
                 * this case include /.extra/ in the search path, but only in this case, and if we run in the
                 * initrd. We don't want to be too eager here, after all /.extra/ is untrusted territory. */

                path = "tpm2-pcr-signature.json";

                if (in_initrd())
                        if (strv_extend(&search, "/.extra") < 0)
                                return log_oom_debug();
        }

        r = search_and_fopen(path, "re", NULL, (const char**) search, &f, &discovered_path);
        if (r < 0)
                return log_debug_errno(r, "Failed to find TPM PCR signature file '%s': %m", path);

        r = json_parse_file(f, discovered_path, 0, ret, NULL, NULL);
        if (r < 0)
                return log_debug_errno(r, "Failed to parse TPM PCR signature JSON object '%s': %m", discovered_path);

        return 0;
}

int tpm2_load_pcr_public_key(const char *path, void **ret_pubkey, size_t *ret_pubkey_size) {
        _cleanup_free_ char *discovered_path = NULL;
        _cleanup_fclose_ FILE *f = NULL;
        int r;

        /* Tries to load a PCR public key file. Takes an absolute path, a simple file name or NULL. In the
         * latter two cases searches in /etc/, /usr/lib/, /run/, as usual. */

        if (!path)
                path = "tpm2-pcr-public-key.pem";

        r = search_and_fopen(path, "re", NULL, (const char**) CONF_PATHS_STRV("systemd"), &f, &discovered_path);
        if (r < 0)
                return log_debug_errno(r, "Failed to find TPM PCR public key file '%s': %m", path);

        r = read_full_stream(f, (char**) ret_pubkey, ret_pubkey_size);
        if (r < 0)
                return log_debug_errno(r, "Failed to load TPM PCR public key PEM file '%s': %m", discovered_path);

        return 0;
}

#define PBKDF2_HMAC_SHA256_ITERATIONS 10000

/*
 * Implements PBKDF2 HMAC SHA256 for a derived keylen of 32
 * bytes and for PBKDF2_HMAC_SHA256_ITERATIONS count.
 * I found the wikipedia entry relevant and it contains links to
 * relevant RFCs:
 *   - https://en.wikipedia.org/wiki/PBKDF2
 *   - https://www.rfc-editor.org/rfc/rfc2898#section-5.2
 */
int tpm2_util_pbkdf2_hmac_sha256(const void *pass,
                    size_t passlen,
                    const void *salt,
                    size_t saltlen,
                    uint8_t ret_key[static SHA256_DIGEST_SIZE]) {

        _cleanup_(erase_and_freep) uint8_t *buffer = NULL;
        uint8_t u[SHA256_DIGEST_SIZE];

        /* To keep this simple, since derived KeyLen (dkLen in docs)
         * Is the same as the hash output, we don't need multiple
         * blocks. Part of the algorithm is to add the block count
         * in, but this can be hardcoded to 1.
         */
        static const uint8_t block_cnt[] = { 0, 0, 0, 1 };

        assert (salt);
        assert (saltlen > 0);
        assert (saltlen <= (SIZE_MAX - sizeof(block_cnt)));
        assert (passlen > 0);

        /*
         * Build a buffer of salt + block_cnt and hmac_sha256 it we
         * do this as we don't have a context builder for HMAC_SHA256.
         */
        buffer = malloc(saltlen + sizeof(block_cnt));
        if (!buffer)
                return -ENOMEM;

        memcpy(buffer, salt, saltlen);
        memcpy(&buffer[saltlen], block_cnt, sizeof(block_cnt));

        hmac_sha256(pass, passlen, buffer, saltlen + sizeof(block_cnt), u);

        /* dk needs to be an unmodified u as u gets modified in the loop */
        memcpy(ret_key, u, SHA256_DIGEST_SIZE);
        uint8_t *dk = ret_key;

        for (size_t i = 1; i < PBKDF2_HMAC_SHA256_ITERATIONS; i++) {
                hmac_sha256(pass, passlen, u, sizeof(u), u);

                for (size_t j=0; j < sizeof(u); j++)
                        dk[j] ^= u[j];
        }

        return 0;
}

static const char* const tpm2_pcr_index_table[_TPM2_PCR_INDEX_MAX_DEFINED] = {
        [TPM2_PCR_PLATFORM_CODE]       = "platform-code",
        [TPM2_PCR_PLATFORM_CONFIG]     = "platform-config",
        [TPM2_PCR_EXTERNAL_CODE]       = "external-code",
        [TPM2_PCR_EXTERNAL_CONFIG]     = "external-config",
        [TPM2_PCR_BOOT_LOADER_CODE]    = "boot-loader-code",
        [TPM2_PCR_BOOT_LOADER_CONFIG]  = "boot-loader-config",
        [TPM2_PCR_HOST_PLATFORM]       = "host-platform",
        [TPM2_PCR_SECURE_BOOT_POLICY]  = "secure-boot-policy",
        [TPM2_PCR_KERNEL_INITRD]       = "kernel-initrd",
        [TPM2_PCR_IMA]                 = "ima",
        [TPM2_PCR_KERNEL_BOOT]         = "kernel-boot",
        [TPM2_PCR_KERNEL_CONFIG]       = "kernel-config",
        [TPM2_PCR_SYSEXTS]             = "sysexts",
        [TPM2_PCR_SHIM_POLICY]         = "shim-policy",
        [TPM2_PCR_SYSTEM_IDENTITY]     = "system-identity",
        [TPM2_PCR_DEBUG]               = "debug",
        [TPM2_PCR_APPLICATION_SUPPORT] = "application-support",
};

DEFINE_STRING_TABLE_LOOKUP_FROM_STRING_WITH_FALLBACK(tpm2_pcr_index, int, TPM2_PCRS_MAX - 1);
DEFINE_STRING_TABLE_LOOKUP_TO_STRING(tpm2_pcr_index, int);