KEYS: Add identifier pointers to public_key_signature struct

Add key identifier pointers to public_key_signature struct so that they can
be used to retain the identifier of the key to be used to verify the
signature in both PKCS#7 and X.509.
Signed-off-by: David Howells <dhowells@redhat.com>

crypto/asymmetric_keys/public_key.c

@@ -72,6 +72,8 @@ void public_key_free(struct public_key *key,
 	}
 
 	if (sig) {
+		for (i = 0; i < ARRAY_SIZE(sig->auth_ids); i++)
+			kfree(sig->auth_ids[i]);
 		for (i = 0; i < ARRAY_SIZE(sig->mpi); i++)
 			mpi_free(sig->mpi[i]);
 		kfree(sig->digest);

include/crypto/public_key.h

@@ -76,6 +76,7 @@ struct public_key {
  * Public key cryptography signature data
  */
 struct public_key_signature {
+	struct asymmetric_key_id *auth_ids[2];
 	u8 *digest;
 	u8 digest_size;			/* Number of bytes in digest */
 	u8 nr_mpi;			/* Occupancy of mpi[] */