1 files changed, 58 insertions, 26 deletions

diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index bb55d6074d5f..6b060b290e77 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -65,23 +65,37 @@ __setup("ca_keys=", ca_keys_setup);
 /**
  * x509_request_asymmetric_key - Request a key by X.509 certificate params.
  * @keyring: The keys to search.
- * @kid: The key ID.
+ * @id: The issuer & serialNumber to look for or NULL.
+ * @skid: The subjectKeyIdentifier to look for or NULL.
  * @partial: Use partial match if true, exact if false.
  *
- * Find a key in the given keyring by subject name and key ID.  These might,
- * for instance, be the issuer name and the authority key ID of an X.509
- * certificate that needs to be verified.
+ * Find a key in the given keyring by identifier.  The preferred identifier is
+ * the issuer + serialNumber and the fallback identifier is the
+ * subjectKeyIdentifier.  If both are given, the lookup is by the former, but
+ * the latter must also match.
  */
 struct key *x509_request_asymmetric_key(struct key *keyring,
-					const struct asymmetric_key_id *kid,
+					const struct asymmetric_key_id *id,
+					const struct asymmetric_key_id *skid,
 					bool partial)
 {
-	key_ref_t key;
-	char *id, *p;
-
+	struct key *key;
+	key_ref_t ref;
+	const char *lookup;
+	char *req, *p;
+	int len;
+
+	if (id) {
+		lookup = id->data;
+		len = id->len;
+	} else {
+		lookup = skid->data;
+		len = skid->len;
+	}
+	
 	/* Construct an identifier "id:<keyid>". */
-	p = id = kmalloc(2 + 1 + kid->len * 2 + 1, GFP_KERNEL);
-	if (!id)
+	p = req = kmalloc(2 + 1 + len * 2 + 1, GFP_KERNEL);
+	if (!req)
 		return ERR_PTR(-ENOMEM);
 
 	if (partial) {
@@ -92,32 +106,48 @@ struct key *x509_request_asymmetric_key(struct key *keyring,
 		*p++ = 'x';
 	}
 	*p++ = ':';
-	p = bin2hex(p, kid->data, kid->len);
+	p = bin2hex(p, lookup, len);
 	*p = 0;
 
-	pr_debug("Look up: \"%s\"\n", id);
+	pr_debug("Look up: \"%s\"\n", req);
 
-	key = keyring_search(make_key_ref(keyring, 1),
-			     &key_type_asymmetric, id);
-	if (IS_ERR(key))
-		pr_debug("Request for key '%s' err %ld\n", id, PTR_ERR(key));
-	kfree(id);
+	ref = keyring_search(make_key_ref(keyring, 1),
+			     &key_type_asymmetric, req);
+	if (IS_ERR(ref))
+		pr_debug("Request for key '%s' err %ld\n", req, PTR_ERR(ref));
+	kfree(req);
 
-	if (IS_ERR(key)) {
-		switch (PTR_ERR(key)) {
+	if (IS_ERR(ref)) {
+		switch (PTR_ERR(ref)) {
 			/* Hide some search errors */
 		case -EACCES:
 		case -ENOTDIR:
 		case -EAGAIN:
 			return ERR_PTR(-ENOKEY);
 		default:
-			return ERR_CAST(key);
+			return ERR_CAST(ref);
+		}
+	}
+
+	key = key_ref_to_ptr(ref);
+	if (id && skid) {
+		const struct asymmetric_key_ids *kids = asymmetric_key_ids(key);
+		if (!kids->id[1]) {
+			pr_debug("issuer+serial match, but expected SKID missing\n");
+			goto reject;
+		}
+		if (!asymmetric_key_id_same(skid, kids->id[1])) {
+			pr_debug("issuer+serial match, but SKID does not\n");
+			goto reject;
 		}
 	}
+	
+	pr_devel("<==%s() = 0 [%x]\n", __func__, key_serial(key));
+	return key;
 
-	pr_devel("<==%s() = 0 [%x]\n", __func__,
-		 key_serial(key_ref_to_ptr(key)));
-	return key_ref_to_ptr(key);
+reject:
+	key_put(key);
+	return ERR_PTR(-EKEYREJECTED);
 }
 EXPORT_SYMBOL_GPL(x509_request_asymmetric_key);
 
@@ -230,7 +260,8 @@ static int x509_validate_trust(struct x509_certificate *cert,
 	if (ca_keyid && !asymmetric_key_id_partial(cert->akid_skid, ca_keyid))
 		return -EPERM;
 
-	key = x509_request_asymmetric_key(trust_keyring, cert->akid_skid,
+	key = x509_request_asymmetric_key(trust_keyring,
+					  cert->akid_id, cert->akid_skid,
 					  false);
 	if (!IS_ERR(key))  {
 		if (!use_builtin_keys
@@ -287,8 +318,9 @@ static int x509_key_preparse(struct key_preparsed_payload *prep)
 	cert->pub->id_type = PKEY_ID_X509;
 
 	/* Check the signature on the key if it appears to be self-signed */
-	if (!cert->akid_skid ||
-	    asymmetric_key_id_same(cert->skid, cert->akid_skid)) {
+	if ((!cert->akid_skid && !cert->akid_id) ||
+	    asymmetric_key_id_same(cert->skid, cert->akid_skid) ||
+	    asymmetric_key_id_same(cert->id, cert->akid_id)) {
 		ret = x509_check_signature(cert->pub, cert); /* self-signed */
 		if (ret < 0)
 			goto error_free_cert;