KEYS: Generalise x509_request_asymmetric_key()

Generalise x509_request_asymmetric_key().  It doesn't really have any
dependencies on X.509 features as it uses generalised IDs and the
public_key structs that contain data extracted from X.509.

Signed-off-by: David Howells <dhowells@redhat.com>

4 files changed, 33 insertions, 35 deletions

diff --git a/crypto/asymmetric_keys/asymmetric_keys.h b/crypto/asymmetric_keys/asymmetric_keys.h
index 1d450b580245..ca8e9ac34ce6 100644
--- a/crypto/asymmetric_keys/asymmetric_keys.h
+++ b/crypto/asymmetric_keys/asymmetric_keys.h
@@ -9,6 +9,8 @@
  * 2 of the Licence, or (at your option) any later version.
  */
 
+#include <keys/asymmetric-type.h>
+
 extern struct asymmetric_key_id *asymmetric_key_hex_to_key_id(const char *id);
 
 extern int __asymmetric_key_hex_to_key_id(const char *id,
diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c
index c4d66cd82860..6600181d5d01 100644
--- a/crypto/asymmetric_keys/asymmetric_type.c
+++ b/crypto/asymmetric_keys/asymmetric_type.c
@@ -35,21 +35,20 @@ static LIST_HEAD(asymmetric_key_parsers);
 static DECLARE_RWSEM(asymmetric_key_parsers_sem);
 
 /**
- * x509_request_asymmetric_key - Request a key by X.509 certificate params.
+ * find_asymmetric_key - Find a key by ID.
  * @keyring: The keys to search.
- * @id: The issuer & serialNumber to look for or NULL.
- * @skid: The subjectKeyIdentifier to look for or NULL.
+ * @id_0: The first ID to look for or NULL.
+ * @id_1: The second ID to look for or NULL.
  * @partial: Use partial match if true, exact if false.
  *
  * 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.
+ * the id_0 and the fallback identifier is the id_1.  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 *id,
-                                        const struct asymmetric_key_id *skid,
-                                        bool partial)
+struct key *find_asymmetric_key(struct key *keyring,
+                                const struct asymmetric_key_id *id_0,
+                                const struct asymmetric_key_id *id_1,
+                                bool partial)
 {
         struct key *key;
         key_ref_t ref;
@@ -57,12 +56,12 @@ struct key *x509_request_asymmetric_key(struct key *keyring,
         char *req, *p;
         int len;
 
-        if (id) {
-                lookup = id->data;
-                len = id->len;
+        if (id_0) {
+                lookup = id_0->data;
+                len = id_0->len;
         } else {
-                lookup = skid->data;
-                len = skid->len;
+                lookup = id_1->data;
+                len = id_1->len;
         }
 
         /* Construct an identifier "id:<keyid>". */
@@ -102,14 +101,15 @@ struct key *x509_request_asymmetric_key(struct key *keyring,
         }
 
         key = key_ref_to_ptr(ref);
-        if (id && skid) {
+        if (id_0 && id_1) {
                 const struct asymmetric_key_ids *kids = asymmetric_key_ids(key);
-                if (!kids->id[1]) {
-                        pr_debug("issuer+serial match, but expected SKID missing\n");
+
+                if (!kids->id[0]) {
+                        pr_debug("First ID matches, but second is missing\n");
                         goto reject;
                 }
-                if (!asymmetric_key_id_same(skid, kids->id[1])) {
-                        pr_debug("issuer+serial match, but SKID does not\n");
+                if (!asymmetric_key_id_same(id_1, kids->id[1])) {
+                        pr_debug("First ID matches, but second does not\n");
                         goto reject;
                 }
         }
@@ -121,7 +121,7 @@ reject:
         key_put(key);
         return ERR_PTR(-EKEYREJECTED);
 }
-EXPORT_SYMBOL_GPL(x509_request_asymmetric_key);
+EXPORT_SYMBOL_GPL(find_asymmetric_key);
 
 /**
  * asymmetric_key_generate_id: Construct an asymmetric key ID
diff --git a/crypto/asymmetric_keys/pkcs7_trust.c b/crypto/asymmetric_keys/pkcs7_trust.c
index 36e77cb07bd0..f6a009d88a33 100644
--- a/crypto/asymmetric_keys/pkcs7_trust.c
+++ b/crypto/asymmetric_keys/pkcs7_trust.c
@@ -51,9 +51,8 @@ static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
                 /* Look to see if this certificate is present in the trusted
                  * keys.
                  */
-                key = x509_request_asymmetric_key(trust_keyring,
-                                                  x509->id, x509->skid,
-                                                  false);
+                key = find_asymmetric_key(trust_keyring,
+                                          x509->id, x509->skid, false);
                 if (!IS_ERR(key)) {
                         /* One of the X.509 certificates in the PKCS#7 message
                          * is apparently the same as one we already trust.
@@ -84,10 +83,10 @@ static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
          * trusted keys.
          */
         if (last && (last->sig->auth_ids[0] || last->sig->auth_ids[1])) {
-                key = x509_request_asymmetric_key(trust_keyring,
-                                                  last->sig->auth_ids[0],
-                                                  last->sig->auth_ids[1],
-                                                  false);
+                key = find_asymmetric_key(trust_keyring,
+                                          last->sig->auth_ids[0],
+                                          last->sig->auth_ids[1],
+                                          false);
                 if (!IS_ERR(key)) {
                         x509 = last;
                         pr_devel("sinfo %u: Root cert %u signer is key %x\n",
@@ -101,10 +100,8 @@ static int pkcs7_validate_trust_one(struct pkcs7_message *pkcs7,
         /* As a last resort, see if we have a trusted public key that matches
          * the signed info directly.
          */
-        key = x509_request_asymmetric_key(trust_keyring,
-                                          sinfo->sig->auth_ids[0],
-                                          NULL,
-                                          false);
+        key = find_asymmetric_key(trust_keyring,
+                                  sinfo->sig->auth_ids[0], NULL, false);
         if (!IS_ERR(key)) {
                 pr_devel("sinfo %u: Direct signer is key %x\n",
                          sinfo->index, key_serial(key));
diff --git a/crypto/asymmetric_keys/x509_public_key.c b/crypto/asymmetric_keys/x509_public_key.c
index 2fb594175cef..9c8483ef1cfe 100644
--- a/crypto/asymmetric_keys/x509_public_key.c
+++ b/crypto/asymmetric_keys/x509_public_key.c
@@ -213,9 +213,8 @@ static int x509_validate_trust(struct x509_certificate *cert,
         if (cert->unsupported_sig)
                 return -ENOPKG;
 
-        key = x509_request_asymmetric_key(trust_keyring,
-                                          sig->auth_ids[0], sig->auth_ids[1],
-                                          false);
+        key = find_asymmetric_key(trust_keyring,
+                                  sig->auth_ids[0], sig->auth_ids[1], false);
         if (IS_ERR(key))
                 return PTR_ERR(key);