From 566a117a8b24e1ae2dfa817cf0c9eec092c783b5 Mon Sep 17 00:00:00 2001 From: David Howells Date: Wed, 6 Apr 2016 16:13:33 +0100 Subject: PKCS#7: Make the signature a pointer rather than embedding it Point to the public_key_signature struct from the pkcs7_signed_info struct rather than embedding it. This makes the code consistent with the X.509 signature handling and makes it possible to have a common cleanup function. We also save a copy of the digest in the signature without sharing the memory with the crypto layer metadata. Signed-off-by: David Howells --- crypto/asymmetric_keys/pkcs7_verify.c | 51 ++++++++++++++++++----------------- 1 file changed, 26 insertions(+), 25 deletions(-) (limited to 'crypto/asymmetric_keys/pkcs7_verify.c') diff --git a/crypto/asymmetric_keys/pkcs7_verify.c b/crypto/asymmetric_keys/pkcs7_verify.c index d8d8d234874e..1426f03e630b 100644 --- a/crypto/asymmetric_keys/pkcs7_verify.c +++ b/crypto/asymmetric_keys/pkcs7_verify.c @@ -25,34 +25,36 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7, struct pkcs7_signed_info *sinfo) { + struct public_key_signature *sig = sinfo->sig; struct crypto_shash *tfm; struct shash_desc *desc; - size_t digest_size, desc_size; - void *digest; + size_t desc_size; int ret; - kenter(",%u,%s", sinfo->index, sinfo->sig.hash_algo); + kenter(",%u,%s", sinfo->index, sinfo->sig->hash_algo); - if (!sinfo->sig.hash_algo) + if (!sinfo->sig->hash_algo) return -ENOPKG; /* Allocate the hashing algorithm we're going to need and find out how * big the hash operational data will be. */ - tfm = crypto_alloc_shash(sinfo->sig.hash_algo, 0, 0); + tfm = crypto_alloc_shash(sinfo->sig->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); - sinfo->sig.digest_size = digest_size = crypto_shash_digestsize(tfm); + sig->digest_size = crypto_shash_digestsize(tfm); ret = -ENOMEM; - digest = kzalloc(ALIGN(digest_size, __alignof__(*desc)) + desc_size, - GFP_KERNEL); - if (!digest) + sig->digest = kmalloc(sig->digest_size, GFP_KERNEL); + if (!sig->digest) + goto error_no_desc; + + desc = kzalloc(desc_size, GFP_KERNEL); + if (!desc) goto error_no_desc; - desc = PTR_ALIGN(digest + digest_size, __alignof__(*desc)); desc->tfm = tfm; desc->flags = CRYPTO_TFM_REQ_MAY_SLEEP; @@ -60,10 +62,11 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7, ret = crypto_shash_init(desc); if (ret < 0) goto error; - ret = crypto_shash_finup(desc, pkcs7->data, pkcs7->data_len, digest); + ret = crypto_shash_finup(desc, pkcs7->data, pkcs7->data_len, + sig->digest); if (ret < 0) goto error; - pr_devel("MsgDigest = [%*ph]\n", 8, digest); + pr_devel("MsgDigest = [%*ph]\n", 8, sig->digest); /* However, if there are authenticated attributes, there must be a * message digest attribute amongst them which corresponds to the @@ -78,14 +81,15 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7, goto error; } - if (sinfo->msgdigest_len != sinfo->sig.digest_size) { + if (sinfo->msgdigest_len != sig->digest_size) { pr_debug("Sig %u: Invalid digest size (%u)\n", sinfo->index, sinfo->msgdigest_len); ret = -EBADMSG; goto error; } - if (memcmp(digest, sinfo->msgdigest, sinfo->msgdigest_len) != 0) { + if (memcmp(sig->digest, sinfo->msgdigest, + sinfo->msgdigest_len) != 0) { pr_debug("Sig %u: Message digest doesn't match\n", sinfo->index); ret = -EKEYREJECTED; @@ -97,7 +101,7 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7, * convert the attributes from a CONT.0 into a SET before we * hash it. */ - memset(digest, 0, sinfo->sig.digest_size); + memset(sig->digest, 0, sig->digest_size); ret = crypto_shash_init(desc); if (ret < 0) @@ -107,17 +111,14 @@ static int pkcs7_digest(struct pkcs7_message *pkcs7, if (ret < 0) goto error; ret = crypto_shash_finup(desc, sinfo->authattrs, - sinfo->authattrs_len, digest); + sinfo->authattrs_len, sig->digest); if (ret < 0) goto error; - pr_devel("AADigest = [%*ph]\n", 8, digest); + pr_devel("AADigest = [%*ph]\n", 8, sig->digest); } - sinfo->sig.digest = digest; - digest = NULL; - error: - kfree(digest); + kfree(desc); error_no_desc: crypto_free_shash(tfm); kleave(" = %d", ret); @@ -144,12 +145,12 @@ static int pkcs7_find_key(struct pkcs7_message *pkcs7, * PKCS#7 message - but I can't be 100% sure of that. It's * possible this will need element-by-element comparison. */ - if (!asymmetric_key_id_same(x509->id, sinfo->signing_cert_id)) + if (!asymmetric_key_id_same(x509->id, sinfo->sig->auth_ids[0])) continue; pr_devel("Sig %u: Found cert serial match X.509[%u]\n", sinfo->index, certix); - if (x509->pub->pkey_algo != sinfo->sig.pkey_algo) { + if (x509->pub->pkey_algo != sinfo->sig->pkey_algo) { pr_warn("Sig %u: X.509 algo and PKCS#7 sig algo don't match\n", sinfo->index); continue; @@ -164,7 +165,7 @@ static int pkcs7_find_key(struct pkcs7_message *pkcs7, */ pr_debug("Sig %u: Issuing X.509 cert not found (#%*phN)\n", sinfo->index, - sinfo->signing_cert_id->len, sinfo->signing_cert_id->data); + sinfo->sig->auth_ids[0]->len, sinfo->sig->auth_ids[0]->data); return 0; } @@ -334,7 +335,7 @@ static int pkcs7_verify_one(struct pkcs7_message *pkcs7, } /* Verify the PKCS#7 binary against the key */ - ret = public_key_verify_signature(sinfo->signer->pub, &sinfo->sig); + ret = public_key_verify_signature(sinfo->signer->pub, sinfo->sig); if (ret < 0) return ret; -- cgit v1.2.3