tpm2: use ref counter for Tpm2Context

This will be used by Tpm2Handle instances, which is added in later patches.

The refcounting allows the context to be retained until all Tpm2Handles have
been cleaned up, and the initial ref is released, before cleaning the context.

diff --git a/src/boot/measure.c b/src/boot/measure.c
index 0d1737200b529bda174780987796878ac1895d08..7b1aca18a18698b7ac67217c3b80d5c6087401cb 100644 (file)
--- a/src/boot/measure.c
+++ b/src/boot/measure.c
@@ -726,7 +726,6 @@ static int verb_sign(int argc, char *argv[], void *userdata) {
         _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
         _cleanup_(pcr_state_free_all) PcrState *pcr_states = NULL;
         _cleanup_(EVP_PKEY_freep) EVP_PKEY *privkey = NULL, *pubkey = NULL;
-        _cleanup_(tpm2_context_destroy) Tpm2Context c = {};
         _cleanup_fclose_ FILE *privkeyf = NULL;
         ESYS_TR session_handle = ESYS_TR_NONE;
         TSS2_RC rc;
@@ -811,7 +810,8 @@ static int verb_sign(int argc, char *argv[], void *userdata) {
         if (r < 0)
                 return r;
 
-        r = tpm2_context_init(arg_tpm2_device, &c);
+        _cleanup_tpm2_context_ Tpm2Context *c = NULL;
+        r = tpm2_context_new(arg_tpm2_device, &c);
         if (r < 0)
                 return r;
 
@@ -830,7 +830,7 @@ static int verb_sign(int argc, char *argv[], void *userdata) {
                         PcrState *p = pcr_states + i;
 
                         rc = sym_Esys_StartAuthSession(
-                                        c.esys_context,
+                                        c->esys_context,
                                         ESYS_TR_NONE,
                                         ESYS_TR_NONE,
                                         ESYS_TR_NONE,
@@ -865,7 +865,7 @@ static int verb_sign(int argc, char *argv[], void *userdata) {
                         tpm2_pcr_mask_to_selection(1 << TPM_PCR_INDEX_KERNEL_IMAGE, tpmalg, &pcr_selection);
 
                         rc = sym_Esys_PolicyPCR(
-                                        c.esys_context,
+                                        c->esys_context,
                                         session_handle,
                                         ESYS_TR_NONE,
                                         ESYS_TR_NONE,
@@ -880,7 +880,7 @@ static int verb_sign(int argc, char *argv[], void *userdata) {
 
                         _cleanup_(Esys_Freep) TPM2B_DIGEST *pcr_policy_digest = NULL;
                         rc = sym_Esys_PolicyGetDigest(
-                                        c.esys_context,
+                                        c->esys_context,
                                         session_handle,
                                         ESYS_TR_NONE,
                                         ESYS_TR_NONE,
@@ -892,7 +892,7 @@ static int verb_sign(int argc, char *argv[], void *userdata) {
                                 goto finish;
                         }
 
-                        session_handle = tpm2_flush_context_verbose(c.esys_context, session_handle);
+                        session_handle = tpm2_flush_context_verbose(c->esys_context, session_handle);
 
                         _cleanup_(EVP_MD_CTX_freep) EVP_MD_CTX* mdctx = NULL;
                         mdctx = EVP_MD_CTX_new();
@@ -983,7 +983,7 @@ static int verb_sign(int argc, char *argv[], void *userdata) {
         r = 0;
 
 finish:
-        session_handle = tpm2_flush_context_verbose(c.esys_context, session_handle);
+        session_handle = tpm2_flush_context_verbose(c->esys_context, session_handle);
         return r;
 }
 

diff --git a/src/boot/pcrphase.c b/src/boot/pcrphase.c
index 057b9f495caa3c9235cc14971a30e9d139f4083b..dc5604a33cb26c7caeda8e87488b9ba7bc2b7a7a 100644 (file)
--- a/src/boot/pcrphase.c
+++ b/src/boot/pcrphase.c
@@ -240,7 +240,6 @@ static int get_file_system_word(
 }
 
 static int run(int argc, char *argv[]) {
-        _cleanup_(tpm2_context_destroy) Tpm2Context c = {};
         _cleanup_free_ char *joined = NULL, *word = NULL;
         unsigned target_pcr_nr;
         size_t length;
@@ -346,11 +345,12 @@ static int run(int argc, char *argv[]) {
         if (r < 0)
                 return log_error_errno(r, "Failed to load TPM2 libraries: %m");
 
-        r = tpm2_context_init(arg_tpm2_device, &c);
+        _cleanup_tpm2_context_ Tpm2Context *c = NULL;
+        r = tpm2_context_new(arg_tpm2_device, &c);
         if (r < 0)
                 return r;
 
-        r = determine_banks(&c, target_pcr_nr);
+        r = determine_banks(c, target_pcr_nr);
         if (r < 0)
                 return r;
         if (strv_isempty(arg_banks)) /* Still none? */
@@ -362,7 +362,7 @@ static int run(int argc, char *argv[]) {
 
         log_debug("Measuring '%s' into PCR index %u, banks %s.", word, target_pcr_nr, joined);
 
-        r = tpm2_extend_bytes(c.esys_context, arg_banks, target_pcr_nr, word, length, NULL, 0);
+        r = tpm2_extend_bytes(c->esys_context, arg_banks, target_pcr_nr, word, length, NULL, 0);
         if (r < 0)
                 return r;
 

diff --git a/src/cryptsetup/cryptsetup.c b/src/cryptsetup/cryptsetup.c
index 27d7c2769a40711a19f07c61274a4a1807793b60..845667eabe84cd1c54e4edc61b3d035b85f87771 100644 (file)
--- a/src/cryptsetup/cryptsetup.c
+++ b/src/cryptsetup/cryptsetup.c
@@ -841,14 +841,14 @@ static int measure_volume_key(
         if (r < 0)
                 return log_error_errno(r, "Failed to load TPM2 libraries: %m");
 
-        _cleanup_(tpm2_context_destroy) Tpm2Context c = {};
-        r = tpm2_context_init(arg_tpm2_device, &c);
+        _cleanup_tpm2_context_ Tpm2Context *c = NULL;
+        r = tpm2_context_new(arg_tpm2_device, &c);
         if (r < 0)
                 return r;
 
         _cleanup_strv_free_ char **l = NULL;
         if (strv_isempty(arg_tpm2_measure_banks)) {
-                r = tpm2_get_good_pcr_banks_strv(c.esys_context, UINT32_C(1) << arg_tpm2_measure_pcr, &l);
+                r = tpm2_get_good_pcr_banks_strv(c->esys_context, UINT32_C(1) << arg_tpm2_measure_pcr, &l);
                 if (r < 0)
                         return r;
         }
@@ -871,7 +871,7 @@ static int measure_volume_key(
         if (!s)
                 return log_oom();
 
-        r = tpm2_extend_bytes(c.esys_context, l ?: arg_tpm2_measure_banks, arg_tpm2_measure_pcr, s, SIZE_MAX, volume_key, volume_key_size);
+        r = tpm2_extend_bytes(c->esys_context, l ?: arg_tpm2_measure_banks, arg_tpm2_measure_pcr, s, SIZE_MAX, volume_key, volume_key_size);
         if (r < 0)
                 return r;
 

diff --git a/src/shared/tpm2-util.c b/src/shared/tpm2-util.c
index 9bbf1bba44332ac424ad46518a87047a3fe51e9c..0b02d7978c6eeef7d1f09c512bc51cbce384ecc3 100644 (file)
--- a/src/shared/tpm2-util.c
+++ b/src/shared/tpm2-util.c
@@ -104,23 +104,21 @@ int dlopen_tpm2(void) {
                         DLSYM_ARG(Tss2_MU_TPM2B_PUBLIC_Unmarshal));
 }
 
-void tpm2_context_destroy(Tpm2Context *c) {
-        assert(c);
+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);
-}
 
-static inline void Esys_Finalize_wrapper(ESYS_CONTEXT **c) {
-        /* A wrapper around Esys_Finalize() for use with _cleanup_(). Only reasons we need this wrapper is
-         * because the function itself warn logs if we'd pass a pointer to NULL, and we don't want that. */
-        if (*c)
-                sym_Esys_Finalize(c);
+        return mfree(c);
 }
 
+DEFINE_TRIVIAL_REF_UNREF_FUNC(Tpm2Context, tpm2_context, tpm2_context_free);
+
 ESYS_TR tpm2_flush_context_verbose(ESYS_CONTEXT *c, ESYS_TR handle) {
         TSS2_RC rc;
 
@@ -138,13 +136,19 @@ ESYS_TR tpm2_flush_context_verbose(ESYS_CONTEXT *c, ESYS_TR handle) {
         return ESYS_TR_NONE;
 }
 
-int tpm2_context_init(const char *device, Tpm2Context *ret) {
-        _cleanup_(Esys_Finalize_wrapper) ESYS_CONTEXT *c = NULL;
-        _cleanup_free_ TSS2_TCTI_CONTEXT *tcti = NULL;
-        _cleanup_(dlclosep) void *dl = NULL;
+int tpm2_context_new(const char *device, Tpm2Context **ret_context) {
+        _cleanup_tpm2_context_ Tpm2Context *context = NULL;
         TSS2_RC rc;
         int r;
 
+        assert(ret_context);
+
+        context = new0(Tpm2Context, 1);
+        if (!context)
+                return log_oom();
+
+        context->n_ref = 1;
+
         r = dlopen_tpm2();
         if (r < 0)
                 return log_error_errno(r, "TPM2 support not installed: %m");
@@ -192,11 +196,11 @@ int tpm2_context_init(const char *device, Tpm2Context *ret) {
                 if (!filename_is_valid(fn))
                         return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "TPM2 driver name '%s' not valid, refusing.", driver);
 
-                dl = dlopen(fn, RTLD_NOW);
-                if (!dl)
+                context->tcti_dl = dlopen(fn, RTLD_NOW);
+                if (!context->tcti_dl)
                         return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Failed to load %s: %s", fn, dlerror());
 
-                func = dlsym(dl, TSS2_TCTI_INFO_SYMBOL);
+                func = dlsym(context->tcti_dl, TSS2_TCTI_INFO_SYMBOL);
                 if (!func)
                         return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                                "Failed to find TCTI info symbol " TSS2_TCTI_INFO_SYMBOL ": %s",
@@ -206,7 +210,6 @@ int tpm2_context_init(const char *device, Tpm2Context *ret) {
                 if (!info)
                         return log_error_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(NULL, &sz, NULL);
@@ -214,22 +217,22 @@ int tpm2_context_init(const char *device, Tpm2Context *ret) {
                         return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                                "Failed to initialize TCTI context: %s", sym_Tss2_RC_Decode(rc));
 
-                tcti = malloc0(sz);
-                if (!tcti)
+                context->tcti_context = malloc0(sz);
+                if (!context->tcti_context)
                         return log_oom();
 
-                rc = info->init(tcti, &sz, param);
+                rc = info->init(context->tcti_context, &sz, param);
                 if (rc != TPM2_RC_SUCCESS)
                         return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                                "Failed to initialize TCTI context: %s", sym_Tss2_RC_Decode(rc));
         }
 
-        rc = sym_Esys_Initialize(&c, tcti, NULL);
+        rc = sym_Esys_Initialize(&context->esys_context, context->tcti_context, NULL);
         if (rc != TSS2_RC_SUCCESS)
                 return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                        "Failed to initialize TPM context: %s", sym_Tss2_RC_Decode(rc));
 
-        rc = sym_Esys_Startup(c, TPM2_SU_CLEAR);
+        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)
@@ -238,11 +241,7 @@ int tpm2_context_init(const char *device, Tpm2Context *ret) {
                 return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                        "Failed to start up TPM: %s", sym_Tss2_RC_Decode(rc));
 
-        *ret = (Tpm2Context) {
-                .esys_context = TAKE_PTR(c),
-                .tcti_context = TAKE_PTR(tcti),
-                .tcti_dl = TAKE_PTR(dl),
-        };
+        *ret_context = TAKE_PTR(context);
 
         return 0;
 }
@@ -1403,7 +1402,6 @@ int tpm2_seal(const char *device,
               uint16_t *ret_pcr_bank,
               uint16_t *ret_primary_alg) {
 
-        _cleanup_(tpm2_context_destroy) Tpm2Context c = {};
         _cleanup_(Esys_Freep) TPM2B_DIGEST *policy_digest = NULL;
         _cleanup_(Esys_Freep) TPM2B_PRIVATE *private = NULL;
         _cleanup_(Esys_Freep) TPM2B_PUBLIC *public = NULL;
@@ -1453,21 +1451,22 @@ int tpm2_seal(const char *device,
 
         CLEANUP_ERASE(hmac_sensitive);
 
-        r = tpm2_context_init(device, &c);
+        _cleanup_tpm2_context_ Tpm2Context *c = NULL;
+        r = tpm2_context_new(device, &c);
         if (r < 0)
                 return r;
 
-        r = tpm2_make_primary(c.esys_context, &primary, 0, &primary_alg);
+        r = tpm2_make_primary(c->esys_context, &primary, 0, &primary_alg);
         if (r < 0)
                 return r;
 
         /* we cannot use the bind key before its created */
-        r = tpm2_make_encryption_session(c.esys_context, primary, ESYS_TR_NONE, NULL, &session);
+        r = tpm2_make_encryption_session(c->esys_context, primary, ESYS_TR_NONE, NULL, &session);
         if (r < 0)
                 goto finish;
 
         r = tpm2_make_policy_session(
-                        c.esys_context,
+                        c->esys_context,
                         primary,
                         session,
                         TPM2_SE_TRIAL,
@@ -1507,7 +1506,7 @@ int tpm2_seal(const char *device,
 
         assert(sizeof(hmac_sensitive.sensitive.data.buffer) >= hmac_sensitive.sensitive.data.size);
 
-        (void) tpm2_credit_random(c.esys_context);
+        (void) tpm2_credit_random(c->esys_context);
 
         log_debug("Generating secret key data.");
 
@@ -1520,7 +1519,7 @@ int tpm2_seal(const char *device,
         log_debug("Creating HMAC key.");
 
         rc = sym_Esys_Create(
-                        c.esys_context,
+                        c->esys_context,
                         primary,
                         session, /* use HMAC session to enable parameter encryption */
                         ESYS_TR_NONE,
@@ -1601,8 +1600,8 @@ int tpm2_seal(const char *device,
         r = 0;
 
 finish:
-        primary = tpm2_flush_context_verbose(c.esys_context, primary);
-        session = tpm2_flush_context_verbose(c.esys_context, session);
+        primary = tpm2_flush_context_verbose(c->esys_context, primary);
+        session = tpm2_flush_context_verbose(c->esys_context, session);
         return r;
 }
 
@@ -1624,7 +1623,6 @@ int tpm2_unseal(const char *device,
                 void **ret_secret,
                 size_t *ret_secret_size) {
 
-        _cleanup_(tpm2_context_destroy) Tpm2Context c = {};
         ESYS_TR primary = ESYS_TR_NONE, session = ESYS_TR_NONE, hmac_session = ESYS_TR_NONE,
                 hmac_key = ESYS_TR_NONE;
         _cleanup_(Esys_Freep) TPM2B_SENSITIVE_DATA* unsealed = NULL;
@@ -1675,11 +1673,12 @@ int tpm2_unseal(const char *device,
                 return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
                                        "Failed to unmarshal public key: %s", sym_Tss2_RC_Decode(rc));
 
-        r = tpm2_context_init(device, &c);
+        _cleanup_tpm2_context_ Tpm2Context *c = NULL;
+        r = tpm2_context_new(device, &c);
         if (r < 0)
                 return r;
 
-        r = tpm2_make_primary(c.esys_context, &primary, primary_alg, NULL);
+        r = tpm2_make_primary(c->esys_context, &primary, primary_alg, NULL);
         if (r < 0)
                 return r;
 
@@ -1692,7 +1691,7 @@ int tpm2_unseal(const char *device,
          * primary key is not verified and they could attack there as well.
          */
         rc = sym_Esys_Load(
-                        c.esys_context,
+                        c->esys_context,
                         primary,
                         ESYS_TR_PASSWORD,
                         ESYS_TR_NONE,
@@ -1715,13 +1714,13 @@ int tpm2_unseal(const char *device,
                 goto finish;
         }
 
-        r = tpm2_make_encryption_session(c.esys_context, primary, hmac_key, pin, &hmac_session);
+        r = tpm2_make_encryption_session(c->esys_context, primary, hmac_key, pin, &hmac_session);
         if (r < 0)
                 goto finish;
 
         for (unsigned i = RETRY_UNSEAL_MAX;; i--) {
                 r = tpm2_make_policy_session(
-                                c.esys_context,
+                                c->esys_context,
                                 primary,
                                 hmac_session,
                                 TPM2_SE_POLICY,
@@ -1748,7 +1747,7 @@ int tpm2_unseal(const char *device,
                 log_debug("Unsealing HMAC key.");
 
                 rc = sym_Esys_Unseal(
-                                c.esys_context,
+                                c->esys_context,
                                 hmac_key,
                                 session,
                                 hmac_session, /* use HMAC session to enable parameter encryption */
@@ -1756,7 +1755,7 @@ int tpm2_unseal(const char *device,
                                 &unsealed);
                 if (rc == TPM2_RC_PCR_CHANGED && i > 0) {
                         log_debug("A PCR value changed during the TPM2 policy session, restarting HMAC key unsealing (%u tries left).", i);
-                        session = tpm2_flush_context_verbose(c.esys_context, session);
+                        session = tpm2_flush_context_verbose(c->esys_context, session);
                         continue;
                 }
                 if (rc != TSS2_RC_SUCCESS) {
@@ -1784,9 +1783,9 @@ int tpm2_unseal(const char *device,
         r = 0;
 
 finish:
-        primary = tpm2_flush_context_verbose(c.esys_context, primary);
-        session = tpm2_flush_context_verbose(c.esys_context, session);
-        hmac_key = tpm2_flush_context_verbose(c.esys_context, hmac_key);
+        primary = tpm2_flush_context_verbose(c->esys_context, primary);
+        session = tpm2_flush_context_verbose(c->esys_context, session);
+        hmac_key = tpm2_flush_context_verbose(c->esys_context, hmac_key);
         return r;
 }
 

diff --git a/src/shared/tpm2-util.h b/src/shared/tpm2-util.h
index d48cbecd42e6fdc37cbac6c035f1de3cae45e8af..bb899319130a91cb8087241194170a51554fae54 100644 (file)
--- a/src/shared/tpm2-util.h
+++ b/src/shared/tpm2-util.h
@@ -54,11 +54,19 @@ int tpm2_seal(const char *device, uint32_t hash_pcr_mask, const void *pubkey, si
 int tpm2_unseal(const char *device, uint32_t hash_pcr_mask, uint16_t pcr_bank, const void *pubkey, size_t pubkey_size, uint32_t pubkey_pcr_mask, JsonVariant *signature, const char *pin, uint16_t primary_alg, const void *blob, size_t blob_size, const void *policy_hash, size_t policy_hash_size, void **ret_secret, size_t *ret_secret_size);
 
 typedef struct {
+        unsigned n_ref;
+
         void *tcti_dl;
         TSS2_TCTI_CONTEXT *tcti_context;
         ESYS_CONTEXT *esys_context;
 } Tpm2Context;
 
+int tpm2_context_new(const char *device, Tpm2Context **ret_context);
+Tpm2Context *tpm2_context_ref(Tpm2Context *context);
+Tpm2Context *tpm2_context_unref(Tpm2Context *context);
+DEFINE_TRIVIAL_CLEANUP_FUNC(Tpm2Context*, tpm2_context_unref);
+#define _cleanup_tpm2_context_ _cleanup_(tpm2_context_unrefp)
+
 ESYS_TR tpm2_flush_context_verbose(ESYS_CONTEXT *c, ESYS_TR handle);
 
 void tpm2_pcr_mask_to_selection(uint32_t mask, uint16_t bank, TPML_PCR_SELECTION *ret);
@@ -77,9 +85,6 @@ int tpm2_extend_bytes(ESYS_CONTEXT *c, char **banks, unsigned pcr_index, const v
 typedef struct {} Tpm2Context;
 #endif /* HAVE_TPM2 */
 
-int tpm2_context_init(const char *device, Tpm2Context *ret);
-void tpm2_context_destroy(Tpm2Context *c);
-
 int tpm2_list_devices(void);
 int tpm2_find_device_auto(int log_level, char **ret);