From b426beb6eeb0c81aeaa419f7444064abc9cb04ae Mon Sep 17 00:00:00 2001 From: David Howells Date: Fri, 30 Aug 2013 16:18:02 +0100 Subject: X.509: Embed public_key_signature struct and create filler function Embed a public_key_signature struct in struct x509_certificate, eliminating now unnecessary fields, and split x509_check_signature() to create a filler function for it that attaches a digest of the signed data and an MPI that represents the signature data. x509_free_certificate() is then modified to deal with these. Whilst we're at it, export both x509_check_signature() and the new x509_get_sig_params(). Signed-off-by: David Howells Reviewed-by: Kees Cook Reviewed-by: Josh Boyer --- crypto/asymmetric_keys/x509_cert_parser.c | 30 +++++------ crypto/asymmetric_keys/x509_parser.h | 16 ++++-- crypto/asymmetric_keys/x509_public_key.c | 83 +++++++++++++++++-------------- 3 files changed, 74 insertions(+), 55 deletions(-) diff --git a/crypto/asymmetric_keys/x509_cert_parser.c b/crypto/asymmetric_keys/x509_cert_parser.c index 8cc253d2dc92..144201ccba0c 100644 --- a/crypto/asymmetric_keys/x509_cert_parser.c +++ b/crypto/asymmetric_keys/x509_cert_parser.c @@ -47,6 +47,8 @@ void x509_free_certificate(struct x509_certificate *cert) kfree(cert->subject); kfree(cert->fingerprint); kfree(cert->authority); + kfree(cert->sig.digest); + mpi_free(cert->sig.rsa.s); kfree(cert); } } @@ -152,33 +154,33 @@ int x509_note_pkey_algo(void *context, size_t hdrlen, return -ENOPKG; /* Unsupported combination */ case OID_md4WithRSAEncryption: - ctx->cert->sig_hash_algo = PKEY_HASH_MD5; - ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA; + ctx->cert->sig.pkey_hash_algo = PKEY_HASH_MD5; + ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA; break; case OID_sha1WithRSAEncryption: - ctx->cert->sig_hash_algo = PKEY_HASH_SHA1; - ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA; + ctx->cert->sig.pkey_hash_algo = PKEY_HASH_SHA1; + ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA; break; case OID_sha256WithRSAEncryption: - ctx->cert->sig_hash_algo = PKEY_HASH_SHA256; - ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA; + ctx->cert->sig.pkey_hash_algo = PKEY_HASH_SHA256; + ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA; break; case OID_sha384WithRSAEncryption: - ctx->cert->sig_hash_algo = PKEY_HASH_SHA384; - ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA; + ctx->cert->sig.pkey_hash_algo = PKEY_HASH_SHA384; + ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA; break; case OID_sha512WithRSAEncryption: - ctx->cert->sig_hash_algo = PKEY_HASH_SHA512; - ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA; + ctx->cert->sig.pkey_hash_algo = PKEY_HASH_SHA512; + ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA; break; case OID_sha224WithRSAEncryption: - ctx->cert->sig_hash_algo = PKEY_HASH_SHA224; - ctx->cert->sig_pkey_algo = PKEY_ALGO_RSA; + ctx->cert->sig.pkey_hash_algo = PKEY_HASH_SHA224; + ctx->cert->sig.pkey_algo = PKEY_ALGO_RSA; break; } @@ -203,8 +205,8 @@ int x509_note_signature(void *context, size_t hdrlen, return -EINVAL; } - ctx->cert->sig = value; - ctx->cert->sig_size = vlen; + ctx->cert->raw_sig = value; + ctx->cert->raw_sig_size = vlen; return 0; } diff --git a/crypto/asymmetric_keys/x509_parser.h b/crypto/asymmetric_keys/x509_parser.h index 2d0118214770..87d9cc26f630 100644 --- a/crypto/asymmetric_keys/x509_parser.h +++ b/crypto/asymmetric_keys/x509_parser.h @@ -21,12 +21,11 @@ struct x509_certificate { char *authority; /* Authority key fingerprint as hex */ struct tm valid_from; struct tm valid_to; - enum pkey_algo sig_pkey_algo : 8; /* Signature public key algorithm */ - enum pkey_hash_algo sig_hash_algo : 8; /* Signature hash algorithm */ const void *tbs; /* Signed data */ - size_t tbs_size; /* Size of signed data */ - const void *sig; /* Signature data */ - size_t sig_size; /* Size of sigature */ + unsigned tbs_size; /* Size of signed data */ + unsigned raw_sig_size; /* Size of sigature */ + const void *raw_sig; /* Signature data */ + struct public_key_signature sig; /* Signature parameters */ }; /* @@ -34,3 +33,10 @@ struct x509_certificate { */ extern void x509_free_certificate(struct x509_certificate *cert); extern struct x509_certificate *x509_cert_parse(const void *data, size_t datalen); + +/* + * x509_public_key.c + */ +extern int x509_get_sig_params(struct x509_certificate *cert); +extern int x509_check_signature(const struct public_key *pub, + struct x509_certificate *cert); diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c index 8cb2f7075479..b7c81d8df08b 100644 --- a/crypto/asymmetric_keys/x509_public_key.c +++ b/crypto/asymmetric_keys/x509_public_key.c @@ -24,72 +24,83 @@ #include "x509_parser.h" /* - * 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_name[cert->sig_hash_algo], 0, 0); + tfm = crypto_alloc_shash(pkey_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 = public_key_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); - -error_mpi: - mpi_free(sig->rsa.s); -error: - kfree(sig); -error_no_sig: - crypto_free_shash(tfm); - - pr_devel("<==%s() = %d\n", __func__, ret); return ret; } +EXPORT_SYMBOL_GPL(x509_check_signature); /* * Attempt to parse a data blob for a key as an X509 certificate. @@ -118,8 +129,8 @@ 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_name[cert->sig_pkey_algo], - pkey_hash_algo_name[cert->sig_hash_algo]); + pkey_algo_name[cert->sig.pkey_algo], + pkey_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", -- cgit v1.2.3-59-g8ed1b