X-Git-Url: http://pileus.org/git/?a=blobdiff_plain;f=crypto%2Fasymmetric_keys%2Fx509_public_key.c;fp=crypto%2Fasymmetric_keys%2Fx509_public_key.c;h=f83300b6e8c13033e5e239be8d48e7fb379668de;hb=78dc53c422172a317adb0776dfb687057ffa28b7;hp=06007f0e880c330903b5536e9d9c194da302738c;hpb=3eaded86ac3e7f00fb3eeb8162d89e9a34e42fb0;p=~andy%2Flinux diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c index 06007f0e880..f83300b6e8c 100644 --- a/crypto/asymmetric_keys/x509_public_key.c +++ b/crypto/asymmetric_keys/x509_public_key.c @@ -18,85 +18,162 @@ #include #include #include +#include #include #include "asymmetric_keys.h" #include "public_key.h" #include "x509_parser.h" -static const -struct public_key_algorithm *x509_public_key_algorithms[PKEY_ALGO__LAST] = { - [PKEY_ALGO_DSA] = NULL, -#if defined(CONFIG_PUBLIC_KEY_ALGO_RSA) || \ - defined(CONFIG_PUBLIC_KEY_ALGO_RSA_MODULE) - [PKEY_ALGO_RSA] = &RSA_public_key_algorithm, -#endif -}; +/* + * Find a key in the given keyring by issuer and authority. + */ +static struct key *x509_request_asymmetric_key( + struct key *keyring, + const char *signer, size_t signer_len, + const char *authority, size_t auth_len) +{ + key_ref_t key; + char *id; + + /* Construct an identifier. */ + id = kmalloc(signer_len + 2 + auth_len + 1, GFP_KERNEL); + if (!id) + return ERR_PTR(-ENOMEM); + + memcpy(id, signer, signer_len); + id[signer_len + 0] = ':'; + id[signer_len + 1] = ' '; + memcpy(id + signer_len + 2, authority, auth_len); + id[signer_len + 2 + auth_len] = 0; + + pr_debug("Look up: \"%s\"\n", id); + + key = keyring_search(make_key_ref(keyring, 1), + &key_type_asymmetric, id); + if (IS_ERR(key)) + pr_debug("Request for module key '%s' err %ld\n", + id, PTR_ERR(key)); + kfree(id); + + if (IS_ERR(key)) { + switch (PTR_ERR(key)) { + /* Hide some search errors */ + case -EACCES: + case -ENOTDIR: + case -EAGAIN: + return ERR_PTR(-ENOKEY); + default: + return ERR_CAST(key); + } + } + + pr_devel("<==%s() = 0 [%x]\n", __func__, key_serial(key_ref_to_ptr(key))); + return key_ref_to_ptr(key); +} /* - * Check the signature on a certificate using the provided public key + * Set up the signature parameters in an X.509 certificate. This involves + * digesting the signed data and extracting the signature. */ -static int x509_check_signature(const struct public_key *pub, - const struct x509_certificate *cert) +int x509_get_sig_params(struct x509_certificate *cert) { - struct public_key_signature *sig; struct crypto_shash *tfm; struct shash_desc *desc; size_t digest_size, desc_size; + void *digest; int ret; pr_devel("==>%s()\n", __func__); - + + if (cert->sig.rsa.s) + return 0; + + cert->sig.rsa.s = mpi_read_raw_data(cert->raw_sig, cert->raw_sig_size); + if (!cert->sig.rsa.s) + return -ENOMEM; + cert->sig.nr_mpi = 1; + /* Allocate the hashing algorithm we're going to need and find out how * big the hash operational data will be. */ - tfm = crypto_alloc_shash(pkey_hash_algo[cert->sig_hash_algo], 0, 0); + tfm = crypto_alloc_shash(hash_algo_name[cert->sig.pkey_hash_algo], 0, 0); if (IS_ERR(tfm)) return (PTR_ERR(tfm) == -ENOENT) ? -ENOPKG : PTR_ERR(tfm); desc_size = crypto_shash_descsize(tfm) + sizeof(*desc); digest_size = crypto_shash_digestsize(tfm); - /* We allocate the hash operational data storage on the end of our - * context data. + /* We allocate the hash operational data storage on the end of the + * digest storage space. */ ret = -ENOMEM; - sig = kzalloc(sizeof(*sig) + desc_size + digest_size, GFP_KERNEL); - if (!sig) - goto error_no_sig; + digest = kzalloc(digest_size + desc_size, GFP_KERNEL); + if (!digest) + goto error; - sig->pkey_hash_algo = cert->sig_hash_algo; - sig->digest = (u8 *)sig + sizeof(*sig) + desc_size; - sig->digest_size = digest_size; + cert->sig.digest = digest; + cert->sig.digest_size = digest_size; - desc = (void *)sig + sizeof(*sig); - desc->tfm = tfm; - desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; + desc = digest + digest_size; + desc->tfm = tfm; + desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; ret = crypto_shash_init(desc); if (ret < 0) goto error; + might_sleep(); + ret = crypto_shash_finup(desc, cert->tbs, cert->tbs_size, digest); +error: + crypto_free_shash(tfm); + pr_devel("<==%s() = %d\n", __func__, ret); + return ret; +} +EXPORT_SYMBOL_GPL(x509_get_sig_params); - ret = -ENOMEM; - sig->rsa.s = mpi_read_raw_data(cert->sig, cert->sig_size); - if (!sig->rsa.s) - goto error; +/* + * Check the signature on a certificate using the provided public key + */ +int x509_check_signature(const struct public_key *pub, + struct x509_certificate *cert) +{ + int ret; - ret = crypto_shash_finup(desc, cert->tbs, cert->tbs_size, sig->digest); - if (ret < 0) - goto error_mpi; + pr_devel("==>%s()\n", __func__); - ret = pub->algo->verify_signature(pub, sig); + ret = x509_get_sig_params(cert); + if (ret < 0) + return ret; + ret = public_key_verify_signature(pub, &cert->sig); pr_debug("Cert Verification: %d\n", ret); + return ret; +} +EXPORT_SYMBOL_GPL(x509_check_signature); -error_mpi: - mpi_free(sig->rsa.s); -error: - kfree(sig); -error_no_sig: - crypto_free_shash(tfm); +/* + * Check the new certificate against the ones in the trust keyring. If one of + * those is the signing key and validates the new certificate, then mark the + * new certificate as being trusted. + * + * Return 0 if the new certificate was successfully validated, 1 if we couldn't + * find a matching parent certificate in the trusted list and an error if there + * is a matching certificate but the signature check fails. + */ +static int x509_validate_trust(struct x509_certificate *cert, + struct key *trust_keyring) +{ + const struct public_key *pk; + struct key *key; + int ret = 1; - pr_devel("<==%s() = %d\n", __func__, ret); + key = x509_request_asymmetric_key(trust_keyring, + cert->issuer, strlen(cert->issuer), + cert->authority, + strlen(cert->authority)); + if (!IS_ERR(key)) { + pk = key->payload.data; + ret = x509_check_signature(pk, cert); + } return ret; } @@ -106,7 +183,6 @@ error_no_sig: static int x509_key_preparse(struct key_preparsed_payload *prep) { struct x509_certificate *cert; - struct tm now; size_t srlen, sulen; char *desc = NULL; int ret; @@ -117,7 +193,18 @@ static int x509_key_preparse(struct key_preparsed_payload *prep) pr_devel("Cert Issuer: %s\n", cert->issuer); pr_devel("Cert Subject: %s\n", cert->subject); - pr_devel("Cert Key Algo: %s\n", pkey_algo[cert->pkey_algo]); + + if (cert->pub->pkey_algo >= PKEY_ALGO__LAST || + cert->sig.pkey_algo >= PKEY_ALGO__LAST || + cert->sig.pkey_hash_algo >= PKEY_HASH__LAST || + !pkey_algo[cert->pub->pkey_algo] || + !pkey_algo[cert->sig.pkey_algo] || + !hash_algo_name[cert->sig.pkey_hash_algo]) { + ret = -ENOPKG; + goto error_free_cert; + } + + pr_devel("Cert Key Algo: %s\n", pkey_algo_name[cert->pub->pkey_algo]); pr_devel("Cert Valid From: %04ld-%02d-%02d %02d:%02d:%02d\n", cert->valid_from.tm_year + 1900, cert->valid_from.tm_mon + 1, cert->valid_from.tm_mday, cert->valid_from.tm_hour, @@ -127,61 +214,29 @@ static int x509_key_preparse(struct key_preparsed_payload *prep) cert->valid_to.tm_mday, cert->valid_to.tm_hour, cert->valid_to.tm_min, cert->valid_to.tm_sec); pr_devel("Cert Signature: %s + %s\n", - pkey_algo[cert->sig_pkey_algo], - pkey_hash_algo[cert->sig_hash_algo]); + pkey_algo_name[cert->sig.pkey_algo], + hash_algo_name[cert->sig.pkey_hash_algo]); - if (!cert->fingerprint || !cert->authority) { - pr_warn("Cert for '%s' must have SubjKeyId and AuthKeyId extensions\n", + if (!cert->fingerprint) { + pr_warn("Cert for '%s' must have a SubjKeyId extension\n", cert->subject); ret = -EKEYREJECTED; goto error_free_cert; } - time_to_tm(CURRENT_TIME.tv_sec, 0, &now); - pr_devel("Now: %04ld-%02d-%02d %02d:%02d:%02d\n", - now.tm_year + 1900, now.tm_mon + 1, now.tm_mday, - now.tm_hour, now.tm_min, now.tm_sec); - if (now.tm_year < cert->valid_from.tm_year || - (now.tm_year == cert->valid_from.tm_year && - (now.tm_mon < cert->valid_from.tm_mon || - (now.tm_mon == cert->valid_from.tm_mon && - (now.tm_mday < cert->valid_from.tm_mday || - (now.tm_mday == cert->valid_from.tm_mday && - (now.tm_hour < cert->valid_from.tm_hour || - (now.tm_hour == cert->valid_from.tm_hour && - (now.tm_min < cert->valid_from.tm_min || - (now.tm_min == cert->valid_from.tm_min && - (now.tm_sec < cert->valid_from.tm_sec - ))))))))))) { - pr_warn("Cert %s is not yet valid\n", cert->fingerprint); - ret = -EKEYREJECTED; - goto error_free_cert; - } - if (now.tm_year > cert->valid_to.tm_year || - (now.tm_year == cert->valid_to.tm_year && - (now.tm_mon > cert->valid_to.tm_mon || - (now.tm_mon == cert->valid_to.tm_mon && - (now.tm_mday > cert->valid_to.tm_mday || - (now.tm_mday == cert->valid_to.tm_mday && - (now.tm_hour > cert->valid_to.tm_hour || - (now.tm_hour == cert->valid_to.tm_hour && - (now.tm_min > cert->valid_to.tm_min || - (now.tm_min == cert->valid_to.tm_min && - (now.tm_sec > cert->valid_to.tm_sec - ))))))))))) { - pr_warn("Cert %s has expired\n", cert->fingerprint); - ret = -EKEYEXPIRED; - goto error_free_cert; - } - - cert->pub->algo = x509_public_key_algorithms[cert->pkey_algo]; + cert->pub->algo = pkey_algo[cert->pub->pkey_algo]; cert->pub->id_type = PKEY_ID_X509; - /* Check the signature on the key */ - if (strcmp(cert->fingerprint, cert->authority) == 0) { - ret = x509_check_signature(cert->pub, cert); + /* Check the signature on the key if it appears to be self-signed */ + if (!cert->authority || + strcmp(cert->fingerprint, cert->authority) == 0) { + ret = x509_check_signature(cert->pub, cert); /* self-signed */ if (ret < 0) goto error_free_cert; + } else { + ret = x509_validate_trust(cert, system_trusted_keyring); + if (!ret) + prep->trusted = 1; } /* Propose a description */ @@ -237,3 +292,6 @@ static void __exit x509_key_exit(void) module_init(x509_key_init); module_exit(x509_key_exit); + +MODULE_DESCRIPTION("X.509 certificate parser"); +MODULE_LICENSE("GPL");