[PATCH 09/23] X.509: Handle certificates that lack anauthorityKeyIdentifier field

[David Howells]

Handle certificates that lack an authorityKeyIdentifier field by assuming
they're self-signed and checking their signatures against themselves.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

 crypto/asymmetric_keys/x509_public_key.c |    9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)


diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index b7c81d8..3a87512 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -132,8 +132,8 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
 		 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",
+	if (!cert->fingerprint) {
+		pr_warn("Cert for '%s' must have a SubjKeyId extension\n",
 			cert->subject);
 		ret = -EKEYREJECTED;
 		goto error_free_cert;
@@ -179,8 +179,9 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
 	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) {
+	/* 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);
 		if (ret < 0)
 			goto error_free_cert;

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/