KEYS: keyring: Provide key preparsing

Provide key preparsing in the keyring so that we can make preparsing
mandatory.  For keyrings, however, only an empty payload is permitted.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Jeff Layton <jlayton@primarydata.com>

1 files changed, 23 insertions, 11 deletions

diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 9cf2575f0d97..8314a7d2104d 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -73,6 +73,8 @@ static inline unsigned keyring_hash(const char *desc)
  * can be treated as ordinary keys in addition to having their own special
  * operations.
  */
+static int keyring_preparse(struct key_preparsed_payload *prep);
+static void keyring_free_preparse(struct key_preparsed_payload *prep);
 static int keyring_instantiate(struct key *keyring,
                                struct key_preparsed_payload *prep);
 static void keyring_revoke(struct key *keyring);
@@ -84,6 +86,8 @@ static long keyring_read(const struct key *keyring,
 struct key_type key_type_keyring = {
         .name           = "keyring",
         .def_datalen    = 0,
+        .preparse       = keyring_preparse,
+        .free_preparse  = keyring_free_preparse,
         .instantiate    = keyring_instantiate,
         .match          = user_match,
         .revoke         = keyring_revoke,
@@ -123,6 +127,21 @@ static void keyring_publish_name(struct key *keyring)
 }
 
 /*
+ * Preparse a keyring payload
+ */
+static int keyring_preparse(struct key_preparsed_payload *prep)
+{
+        return prep->datalen != 0 ? -EINVAL : 0;
+}
+
+/*
+ * Free a preparse of a user defined key payload
+ */
+static void keyring_free_preparse(struct key_preparsed_payload *prep)
+{
+}
+
+/*
  * Initialise a keyring.
  *
  * Returns 0 on success, -EINVAL if given any data.
@@ -130,17 +149,10 @@ static void keyring_publish_name(struct key *keyring)
 static int keyring_instantiate(struct key *keyring,
                                struct key_preparsed_payload *prep)
 {
-        int ret;
-
-        ret = -EINVAL;
-        if (prep->datalen == 0) {
-                assoc_array_init(&keyring->keys);
-                /* make the keyring available by name if it has one */
-                keyring_publish_name(keyring);
-                ret = 0;
-        }
-
-        return ret;
+        assoc_array_init(&keyring->keys);
+        /* make the keyring available by name if it has one */
+        keyring_publish_name(keyring);
+        return 0;
 }
 
 /*