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 <dhowells@redhat.com>

1 files changed, 23 insertions, 15 deletions

diff --git a/crypto/asymmetric_keys/pkcs7_parser.c b/crypto/asymmetric_keys/pkcs7_parser.c
index 40de03f49ff8..835701613125 100644
--- a/crypto/asymmetric_keys/pkcs7_parser.c
+++ b/crypto/asymmetric_keys/pkcs7_parser.c
@@ -44,9 +44,7 @@ struct pkcs7_parse_context {
 static void pkcs7_free_signed_info(struct pkcs7_signed_info *sinfo)
 {
 	if (sinfo) {
-		kfree(sinfo->sig.s);
-		kfree(sinfo->sig.digest);
-		kfree(sinfo->signing_cert_id);
+		public_key_signature_free(sinfo->sig);
 		kfree(sinfo);
 	}
 }
@@ -125,6 +123,10 @@ struct pkcs7_message *pkcs7_parse_message(const void *data, size_t datalen)
 	ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);
 	if (!ctx->sinfo)
 		goto out_no_sinfo;
+	ctx->sinfo->sig = kzalloc(sizeof(struct public_key_signature),
+				  GFP_KERNEL);
+	if (!ctx->sinfo->sig)
+		goto out_no_sig;
 
 	ctx->data = (unsigned long)data;
 	ctx->ppcerts = &ctx->certs;
@@ -150,6 +152,7 @@ out:
 		ctx->certs = cert->next;
 		x509_free_certificate(cert);
 	}
+out_no_sig:
 	pkcs7_free_signed_info(ctx->sinfo);
 out_no_sinfo:
 	pkcs7_free_message(ctx->msg);
@@ -218,25 +221,26 @@ int pkcs7_sig_note_digest_algo(void *context, size_t hdrlen,
 
 	switch (ctx->last_oid) {
 	case OID_md4:
-		ctx->sinfo->sig.hash_algo = "md4";
+		ctx->sinfo->sig->hash_algo = "md4";
 		break;
 	case OID_md5:
-		ctx->sinfo->sig.hash_algo = "md5";
+		ctx->sinfo->sig->hash_algo = "md5";
 		break;
 	case OID_sha1:
-		ctx->sinfo->sig.hash_algo = "sha1";
+		ctx->sinfo->sig->hash_algo = "sha1";
 		break;
 	case OID_sha256:
-		ctx->sinfo->sig.hash_algo = "sha256";
+		ctx->sinfo->sig->hash_algo = "sha256";
 		break;
 	case OID_sha384:
-		ctx->sinfo->sig.hash_algo = "sha384";
+		ctx->sinfo->sig->hash_algo = "sha384";
 		break;
 	case OID_sha512:
-		ctx->sinfo->sig.hash_algo = "sha512";
+		ctx->sinfo->sig->hash_algo = "sha512";
 		break;
 	case OID_sha224:
-		ctx->sinfo->sig.hash_algo = "sha224";
+		ctx->sinfo->sig->hash_algo = "sha224";
+		break;
 	default:
 		printk("Unsupported digest algo: %u\n", ctx->last_oid);
 		return -ENOPKG;
@@ -255,7 +259,7 @@ int pkcs7_sig_note_pkey_algo(void *context, size_t hdrlen,
 
 	switch (ctx->last_oid) {
 	case OID_rsaEncryption:
-		ctx->sinfo->sig.pkey_algo = "rsa";
+		ctx->sinfo->sig->pkey_algo = "rsa";
 		break;
 	default:
 		printk("Unsupported pkey algo: %u\n", ctx->last_oid);
@@ -615,11 +619,11 @@ int pkcs7_sig_note_signature(void *context, size_t hdrlen,
 {
 	struct pkcs7_parse_context *ctx = context;
 
-	ctx->sinfo->sig.s = kmemdup(value, vlen, GFP_KERNEL);
-	if (!ctx->sinfo->sig.s)
+	ctx->sinfo->sig->s = kmemdup(value, vlen, GFP_KERNEL);
+	if (!ctx->sinfo->sig->s)
 		return -ENOMEM;
 
-	ctx->sinfo->sig.s_size = vlen;
+	ctx->sinfo->sig->s_size = vlen;
 	return 0;
 }
 
@@ -655,12 +659,16 @@ int pkcs7_note_signed_info(void *context, size_t hdrlen,
 
 	pr_devel("SINFO KID: %u [%*phN]\n", kid->len, kid->len, kid->data);
 
-	sinfo->signing_cert_id = kid;
+	sinfo->sig->auth_ids[0] = kid;
 	sinfo->index = ++ctx->sinfo_index;
 	*ctx->ppsinfo = sinfo;
 	ctx->ppsinfo = &sinfo->next;
 	ctx->sinfo = kzalloc(sizeof(struct pkcs7_signed_info), GFP_KERNEL);
 	if (!ctx->sinfo)
 		return -ENOMEM;
+	ctx->sinfo->sig = kzalloc(sizeof(struct public_key_signature),
+				  GFP_KERNEL);
+	if (!ctx->sinfo->sig)
+		return -ENOMEM;
 	return 0;
 }