--- /dev/null
+/* SPDX-License-Identifier: LGPL-2.1+ */
+
+#include "errno-util.h"
+#include "format-table.h"
+#include "hexdecoct.h"
+#include "homectl-pkcs11.h"
+#include "libcrypt-util.h"
+#include "memory-util.h"
+#include "openssl-util.h"
+#include "pkcs11-util.h"
+#include "random-util.h"
+#include "strv.h"
+
+struct pkcs11_callback_data {
+ char *pin_used;
+ X509 *cert;
+};
+
+static void pkcs11_callback_data_release(struct pkcs11_callback_data *data) {
+ erase_and_free(data->pin_used);
+ X509_free(data->cert);
+}
+
+#if HAVE_P11KIT
+static int pkcs11_callback(
+ CK_FUNCTION_LIST *m,
+ CK_SESSION_HANDLE session,
+ CK_SLOT_ID slot_id,
+ const CK_SLOT_INFO *slot_info,
+ const CK_TOKEN_INFO *token_info,
+ P11KitUri *uri,
+ void *userdata) {
+
+ _cleanup_(erase_and_freep) char *pin_used = NULL;
+ struct pkcs11_callback_data *data = userdata;
+ CK_OBJECT_HANDLE object;
+ int r;
+
+ assert(m);
+ assert(slot_info);
+ assert(token_info);
+ assert(uri);
+ assert(data);
+
+ /* Called for every token matching our URI */
+
+ r = pkcs11_token_login(m, session, slot_id, token_info, "home directory operation", "user-home", "pkcs11-pin", UINT64_MAX, &pin_used);
+ if (r < 0)
+ return r;
+
+ r = pkcs11_token_find_x509_certificate(m, session, uri, &object);
+ if (r < 0)
+ return r;
+
+ r = pkcs11_token_read_x509_certificate(m, session, object, &data->cert);
+ if (r < 0)
+ return r;
+
+ /* Let's read some random data off the token and write it to the kernel pool before we generate our
+ * random key from it. This way we can claim the quality of the RNG is at least as good as the
+ * kernel's and the token's pool */
+ (void) pkcs11_token_acquire_rng(m, session);
+
+ data->pin_used = TAKE_PTR(pin_used);
+ return 1;
+}
+#endif
+
+static int acquire_pkcs11_certificate(
+ const char *uri,
+ X509 **ret_cert,
+ char **ret_pin_used) {
+
+#if HAVE_P11KIT
+ _cleanup_(pkcs11_callback_data_release) struct pkcs11_callback_data data = {};
+ int r;
+
+ r = pkcs11_find_token(uri, pkcs11_callback, &data);
+ if (r == -EAGAIN) /* pkcs11_find_token() doesn't log about this error, but all others */
+ return log_error_errno(ENXIO, "Specified PKCS#11 token with URI '%s' not found.", uri);
+ if (r < 0)
+ return r;
+
+ *ret_cert = TAKE_PTR(data.cert);
+ *ret_pin_used = TAKE_PTR(data.pin_used);
+
+ return 0;
+#else
+ return log_error_errno(EOPNOTSUPP, "PKCS#11 tokens not supported on this build.");
+#endif
+}
+
+static int encrypt_bytes(
+ EVP_PKEY *pkey,
+ const void *decrypted_key,
+ size_t decrypted_key_size,
+ void **ret_encrypt_key,
+ size_t *ret_encrypt_key_size) {
+
+ _cleanup_(EVP_PKEY_CTX_freep) EVP_PKEY_CTX *ctx = NULL;
+ _cleanup_free_ void *b = NULL;
+ size_t l;
+
+ ctx = EVP_PKEY_CTX_new(pkey, NULL);
+ if (!ctx)
+ return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to allocate public key context");
+
+ if (EVP_PKEY_encrypt_init(ctx) <= 0)
+ return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to initialize public key context");
+
+ if (EVP_PKEY_CTX_set_rsa_padding(ctx, RSA_PKCS1_PADDING) <= 0)
+ return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to configure PKCS#1 padding");
+
+ if (EVP_PKEY_encrypt(ctx, NULL, &l, decrypted_key, decrypted_key_size) <= 0)
+ return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to determine encrypted key size");
+
+ b = malloc(l);
+ if (!b)
+ return log_oom();
+
+ if (EVP_PKEY_encrypt(ctx, b, &l, decrypted_key, decrypted_key_size) <= 0)
+ return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to determine encrypted key size");
+
+ *ret_encrypt_key = TAKE_PTR(b);
+ *ret_encrypt_key_size = l;
+
+ return 0;
+}
+
+static int add_pkcs11_encrypted_key(
+ JsonVariant **v,
+ const char *uri,
+ const void *encrypted_key, size_t encrypted_key_size,
+ const void *decrypted_key, size_t decrypted_key_size) {
+
+ _cleanup_(json_variant_unrefp) JsonVariant *l = NULL, *w = NULL, *e = NULL;
+ _cleanup_(erase_and_freep) char *base64_encoded = NULL;
+ _cleanup_free_ char *salt = NULL;
+ struct crypt_data cd = {};
+ char *k;
+ int r;
+
+ assert(v);
+ assert(uri);
+ assert(encrypted_key);
+ assert(encrypted_key_size > 0);
+ assert(decrypted_key);
+ assert(decrypted_key_size > 0);
+
+ r = make_salt(&salt);
+ if (r < 0)
+ return log_error_errno(r, "Failed to generate salt: %m");
+
+ /* Before using UNIX hashing on the supplied key we base64 encode it, since crypt_r() and friends
+ * expect a NUL terminated string, and we use a binary key */
+ r = base64mem(decrypted_key, decrypted_key_size, &base64_encoded);
+ if (r < 0)
+ return log_error_errno(r, "Failed to base64 encode secret key: %m");
+
+ errno = 0;
+ k = crypt_r(base64_encoded, salt, &cd);
+ if (!k)
+ return log_error_errno(errno_or_else(EINVAL), "Failed to UNIX hash secret key: %m");
+
+ r = json_build(&e, JSON_BUILD_OBJECT(
+ JSON_BUILD_PAIR("uri", JSON_BUILD_STRING(uri)),
+ JSON_BUILD_PAIR("data", JSON_BUILD_BASE64(encrypted_key, encrypted_key_size)),
+ JSON_BUILD_PAIR("hashedPassword", JSON_BUILD_STRING(k))));
+ if (r < 0)
+ return log_error_errno(r, "Failed to build encrypted JSON key object: %m");
+
+ w = json_variant_ref(json_variant_by_key(*v, "privileged"));
+ l = json_variant_ref(json_variant_by_key(w, "pkcs11EncryptedKey"));
+
+ r = json_variant_append_array(&l, e);
+ if (r < 0)
+ return log_error_errno(r, "Failed append PKCS#11 encrypted key: %m");
+
+ r = json_variant_set_field(&w, "pkcs11EncryptedKey", l);
+ if (r < 0)
+ return log_error_errno(r, "Failed to set PKCS#11 encrypted key: %m");
+
+ r = json_variant_set_field(v, "privileged", w);
+ if (r < 0)
+ return log_error_errno(r, "Failed to update privileged field: %m");
+
+ return 0;
+}
+
+static int add_pkcs11_token_uri(JsonVariant **v, const char *uri) {
+ _cleanup_(json_variant_unrefp) JsonVariant *w = NULL;
+ _cleanup_strv_free_ char **l = NULL;
+ int r;
+
+ assert(v);
+ assert(uri);
+
+ w = json_variant_ref(json_variant_by_key(*v, "pkcs11TokenUri"));
+ if (w) {
+ r = json_variant_strv(w, &l);
+ if (r < 0)
+ return log_error_errno(r, "Failed to parse PKCS#11 token list: %m");
+
+ if (strv_contains(l, uri))
+ return 0;
+ }
+
+ r = strv_extend(&l, uri);
+ if (r < 0)
+ return log_oom();
+
+ w = json_variant_unref(w);
+ r = json_variant_new_array_strv(&w, l);
+ if (r < 0)
+ return log_error_errno(r, "Failed to create PKCS#11 token URI JSON: %m");
+
+ r = json_variant_set_field(v, "pkcs11TokenUri", w);
+ if (r < 0)
+ return log_error_errno(r, "Failed to update PKCS#11 token URI list: %m");
+
+ return 0;
+}
+
+int identity_add_token_pin(JsonVariant **v, const char *pin) {
+ _cleanup_(json_variant_unrefp) JsonVariant *w = NULL, *l = NULL;
+ _cleanup_(strv_free_erasep) char **pins = NULL;
+ int r;
+
+ assert(v);
+
+ if (isempty(pin))
+ return 0;
+
+ w = json_variant_ref(json_variant_by_key(*v, "secret"));
+ l = json_variant_ref(json_variant_by_key(w, "tokenPin"));
+
+ r = json_variant_strv(l, &pins);
+ if (r < 0)
+ return log_error_errno(r, "Failed to convert PIN array: %m");
+
+ if (strv_find(pins, pin))
+ return 0;
+
+ r = strv_extend(&pins, pin);
+ if (r < 0)
+ return log_oom();
+
+ strv_uniq(pins);
+
+ l = json_variant_unref(l);
+
+ r = json_variant_new_array_strv(&l, pins);
+ if (r < 0)
+ return log_error_errno(r, "Failed to allocate new PIN array JSON: %m");
+
+ json_variant_sensitive(l);
+
+ r = json_variant_set_field(&w, "tokenPin", l);
+ if (r < 0)
+ return log_error_errno(r, "Failed to update PIN field: %m");
+
+ r = json_variant_set_field(v, "secret", w);
+ if (r < 0)
+ return log_error_errno(r, "Failed to update secret object: %m");
+
+ return 1;
+}
+
+int identity_add_pkcs11_key_data(JsonVariant **v, const char *uri) {
+ _cleanup_(erase_and_freep) void *decrypted_key = NULL, *encrypted_key = NULL;
+ _cleanup_(erase_and_freep) char *pin = NULL;
+ size_t decrypted_key_size, encrypted_key_size;
+ _cleanup_(X509_freep) X509 *cert = NULL;
+ EVP_PKEY *pkey;
+ RSA *rsa;
+ int bits;
+ int r;
+
+ assert(v);
+
+ r = acquire_pkcs11_certificate(uri, &cert, &pin);
+ if (r < 0)
+ return r;
+
+ pkey = X509_get0_pubkey(cert);
+ if (!pkey)
+ return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to extract public key from X.509 certificate.");
+
+ if (EVP_PKEY_base_id(pkey) != EVP_PKEY_RSA)
+ return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "X.509 certificate does not refer to RSA key.");
+
+ rsa = EVP_PKEY_get0_RSA(pkey);
+ if (!rsa)
+ return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to acquire RSA public key from X.509 certificate.");
+
+ bits = RSA_bits(rsa);
+ log_debug("Bits in RSA key: %i", bits);
+
+ /* We use PKCS#1 padding for the RSA cleartext, hence let's leave some extra space for it, hence only
+ * generate a random key half the size of the RSA length */
+ decrypted_key_size = bits / 8 / 2;
+
+ if (decrypted_key_size < 1)
+ return log_error_errno(SYNTHETIC_ERRNO(EIO), "Uh, RSA key size too short?");
+
+ log_debug("Generating %zu bytes random key.", decrypted_key_size);
+
+ decrypted_key = malloc(decrypted_key_size);
+ if (!decrypted_key)
+ return log_oom();
+
+ r = genuine_random_bytes(decrypted_key, decrypted_key_size, RANDOM_BLOCK);
+ if (r < 0)
+ return log_error_errno(r, "Failed to generate random key: %m");
+
+ r = encrypt_bytes(pkey, decrypted_key, decrypted_key_size, &encrypted_key, &encrypted_key_size);
+ if (r < 0)
+ return log_error_errno(r, "Failed to encrypt key: %m");
+
+ /* Add the token URI to the public part of the record. */
+ r = add_pkcs11_token_uri(v, uri);
+ if (r < 0)
+ return r;
+
+ /* Include the encrypted version of the random key we just generated in the privileged part of the record */
+ r = add_pkcs11_encrypted_key(
+ v,
+ uri,
+ encrypted_key, encrypted_key_size,
+ decrypted_key, decrypted_key_size);
+ if (r < 0)
+ return r;
+
+ /* If we acquired the PIN also include it in the secret section of the record, so that systemd-homed
+ * can use it if it needs to, given that it likely needs to decrypt the key again to pass to LUKS or
+ * fscrypt. */
+ r = identity_add_token_pin(v, pin);
+ if (r < 0)
+ return r;
+
+ return 0;
+}
+
+#if HAVE_P11KIT
+static int list_callback(
+ CK_FUNCTION_LIST *m,
+ CK_SESSION_HANDLE session,
+ CK_SLOT_ID slot_id,
+ const CK_SLOT_INFO *slot_info,
+ const CK_TOKEN_INFO *token_info,
+ P11KitUri *uri,
+ void *userdata) {
+
+ _cleanup_free_ char *token_uri_string = NULL, *token_label = NULL, *token_manufacturer_id = NULL, *token_model = NULL;
+ _cleanup_(p11_kit_uri_freep) P11KitUri *token_uri = NULL;
+ Table *t = userdata;
+ int uri_result, r;
+
+ assert(slot_info);
+ assert(token_info);
+
+ /* We only care about hardware devices here with a token inserted. Let's filter everything else
+ * out. (Note that the user can explicitly specify non-hardware tokens if they like, but during
+ * enumeration we'll filter those, since software tokens are typically the system certificate store
+ * and such, and it's typically not what people want to bind their home directories to.) */
+ if (!FLAGS_SET(token_info->flags, CKF_HW_SLOT|CKF_TOKEN_PRESENT))
+ return -EAGAIN;
+
+ token_label = pkcs11_token_label(token_info);
+ if (!token_label)
+ return log_oom();
+
+ token_manufacturer_id = pkcs11_token_manufacturer_id(token_info);
+ if (!token_manufacturer_id)
+ return log_oom();
+
+ token_model = pkcs11_token_model(token_info);
+ if (!token_model)
+ return log_oom();
+
+ token_uri = uri_from_token_info(token_info);
+ if (!token_uri)
+ return log_oom();
+
+ uri_result = p11_kit_uri_format(token_uri, P11_KIT_URI_FOR_ANY, &token_uri_string);
+ if (uri_result != P11_KIT_URI_OK)
+ return log_warning_errno(SYNTHETIC_ERRNO(EAGAIN), "Failed to format slot URI: %s", p11_kit_uri_message(uri_result));
+
+ r = table_add_many(
+ t,
+ TABLE_STRING, token_uri_string,
+ TABLE_STRING, token_label,
+ TABLE_STRING, token_manufacturer_id,
+ TABLE_STRING, token_model);
+ if (r < 0)
+ return table_log_add_error(r);
+
+ return -EAGAIN; /* keep scanning */
+}
+#endif
+
+int list_pkcs11_tokens(void) {
+#if HAVE_P11KIT
+ _cleanup_(table_unrefp) Table *t = NULL;
+ int r;
+
+ t = table_new("uri", "label", "manufacturer", "model");
+ if (!t)
+ return log_oom();
+
+ r = pkcs11_find_token(NULL, list_callback, t);
+ if (r < 0 && r != -EAGAIN)
+ return r;
+
+ if (table_get_rows(t) <= 1) {
+ log_info("No suitable PKCS#11 tokens 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(EOPNOTSUPP, "PKCS#11 tokens not supported on this build.");
+#endif
+}
+
+#if HAVE_P11KIT
+static int auto_callback(
+ CK_FUNCTION_LIST *m,
+ CK_SESSION_HANDLE session,
+ CK_SLOT_ID slot_id,
+ const CK_SLOT_INFO *slot_info,
+ const CK_TOKEN_INFO *token_info,
+ P11KitUri *uri,
+ void *userdata) {
+
+ _cleanup_(p11_kit_uri_freep) P11KitUri *token_uri = NULL;
+ char **t = userdata;
+ int uri_result;
+
+ assert(slot_info);
+ assert(token_info);
+
+ if (!FLAGS_SET(token_info->flags, CKF_HW_SLOT|CKF_TOKEN_PRESENT))
+ return -EAGAIN;
+
+ if (*t)
+ return log_error_errno(SYNTHETIC_ERRNO(ENOTUNIQ),
+ "More than one suitable PKCS#11 token found.");
+
+ token_uri = uri_from_token_info(token_info);
+ if (!token_uri)
+ return log_oom();
+
+ uri_result = p11_kit_uri_format(token_uri, P11_KIT_URI_FOR_ANY, t);
+ if (uri_result != P11_KIT_URI_OK)
+ return log_warning_errno(SYNTHETIC_ERRNO(EAGAIN), "Failed to format slot URI: %s", p11_kit_uri_message(uri_result));
+
+ return 0;
+}
+#endif
+
+int find_pkcs11_token_auto(char **ret) {
+#if HAVE_P11KIT
+ int r;
+
+ r = pkcs11_find_token(NULL, auto_callback, ret);
+ if (r == -EAGAIN)
+ return log_error_errno(SYNTHETIC_ERRNO(ENODEV), "No suitable PKCS#11 tokens found.");
+ if (r < 0)
+ return r;
+
+ return 0;
+#else
+ return log_error_errno(EOPNOTSUPP, "PKCS#11 tokens not supported on this build.");
+#endif
+}
projects / thirdparty / systemd.git / blobdiff