KEYS: Remove key_type::match in favour of overriding default by match_preparse

A previous patch added a ->match_preparse() method to the key type.  This is
allowed to override the function called by the iteration algorithm.
Therefore, we can just set a default that simply checks for an exact match of
the key description with the original criterion data and allow match_preparse
to override it as needed.

The key_type::match op is then redundant and can be removed, as can the
user_match() function.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>

9 files changed, 15 insertions, 23 deletions

diff --git a/security/keys/big_key.c b/security/keys/big_key.c
index 4045c13a761a..b6adb94f6d52 100644
--- a/security/keys/big_key.c
+++ b/security/keys/big_key.c
@@ -36,7 +36,6 @@ struct key_type key_type_big_key = {
         .preparse               = big_key_preparse,
         .free_preparse          = big_key_free_preparse,
         .instantiate            = generic_key_instantiate,
-        .match                  = user_match,
         .revoke                 = big_key_revoke,
         .destroy                = big_key_destroy,
         .describe               = big_key_describe,
diff --git a/security/keys/encrypted-keys/encrypted.c b/security/keys/encrypted-keys/encrypted.c
index 5fe443d120af..db9675db1026 100644
--- a/security/keys/encrypted-keys/encrypted.c
+++ b/security/keys/encrypted-keys/encrypted.c
@@ -970,7 +970,6 @@ struct key_type key_type_encrypted = {
         .name = "encrypted",
         .instantiate = encrypted_instantiate,
         .update = encrypted_update,
-        .match = user_match,
         .destroy = encrypted_destroy,
         .describe = user_describe,
         .read = encrypted_read,
diff --git a/security/keys/internal.h b/security/keys/internal.h
index b47cc532be1e..e66a16cb63e1 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -127,6 +127,8 @@ struct keyring_search_context {
         struct timespec         now;
 };
 
+extern int key_default_cmp(const struct key *key,
+                           const struct key_match_data *match_data);
 extern key_ref_t keyring_search_aux(key_ref_t keyring_ref,
                                     struct keyring_search_context *ctx);
 
diff --git a/security/keys/key.c b/security/keys/key.c
index b90a68c4e2c4..8c0092ca0443 100644
--- a/security/keys/key.c
+++ b/security/keys/key.c
@@ -799,7 +799,7 @@ key_ref_t key_create_or_update(key_ref_t keyring_ref,
         }
 
         key_ref = ERR_PTR(-EINVAL);
-        if (!index_key.type->match || !index_key.type->instantiate ||
+        if (!index_key.type->instantiate ||
             (!index_key.description && !index_key.type->preparse))
                 goto error_put_type;
 
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 10f0a5f2d362..253c9a0eb092 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -89,7 +89,6 @@ struct key_type key_type_keyring = {
         .preparse       = keyring_preparse,
         .free_preparse  = keyring_free_preparse,
         .instantiate    = keyring_instantiate,
-        .match          = user_match,
         .revoke         = keyring_revoke,
         .destroy        = keyring_destroy,
         .describe       = keyring_describe,
@@ -512,6 +511,15 @@ struct key *keyring_alloc(const char *description, kuid_t uid, kgid_t gid,
 EXPORT_SYMBOL(keyring_alloc);
 
 /*
+ * By default, we keys found by getting an exact match on their descriptions.
+ */
+int key_default_cmp(const struct key *key,
+                    const struct key_match_data *match_data)
+{
+        return strcmp(key->description, match_data->raw_data) == 0;
+}
+
+/*
  * Iteration function to consider each key found.
  */
 static int keyring_search_iterator(const void *object, void *iterator_data)
@@ -884,7 +892,7 @@ key_ref_t keyring_search(key_ref_t keyring,
                 .index_key.type         = type,
                 .index_key.description  = description,
                 .cred                   = current_cred(),
-                .match_data.cmp         = type->match,
+                .match_data.cmp         = key_default_cmp,
                 .match_data.raw_data    = description,
                 .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
                 .flags                  = KEYRING_SEARCH_DO_STATE_CHECK,
@@ -892,9 +900,6 @@ key_ref_t keyring_search(key_ref_t keyring,
         key_ref_t key;
         int ret;
 
-        if (!ctx.match_data.cmp)
-                return ERR_PTR(-ENOKEY);
-
         if (type->match_preparse) {
                 ret = type->match_preparse(&ctx.match_data);
                 if (ret < 0)
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 408523e5e2e2..dc6ed32b7844 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -531,7 +531,7 @@ struct key *request_key_and_link(struct key_type *type,
                 .index_key.type         = type,
                 .index_key.description  = description,
                 .cred                   = current_cred(),
-                .match_data.cmp         = type->match,
+                .match_data.cmp         = key_default_cmp,
                 .match_data.raw_data    = description,
                 .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
         };
diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c
index 9ae02819cc06..6639e2cb8853 100644
--- a/security/keys/request_key_auth.c
+++ b/security/keys/request_key_auth.c
@@ -246,7 +246,7 @@ struct key *key_get_instantiation_authkey(key_serial_t target_id)
                 .index_key.type         = &key_type_request_key_auth,
                 .index_key.description  = description,
                 .cred                   = current_cred(),
-                .match_data.cmp         = user_match,
+                .match_data.cmp         = key_default_cmp,
                 .match_data.raw_data    = description,
                 .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
         };
diff --git a/security/keys/trusted.c b/security/keys/trusted.c
index 6b804aa4529a..c0594cb07ada 100644
--- a/security/keys/trusted.c
+++ b/security/keys/trusted.c
@@ -1096,7 +1096,6 @@ struct key_type key_type_trusted = {
         .name = "trusted",
         .instantiate = trusted_instantiate,
         .update = trusted_update,
-        .match = user_match,
         .destroy = trusted_destroy,
         .describe = user_describe,
         .read = trusted_read,
diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c
index cd7e726e8646..36b47bbd3d8c 100644
--- a/security/keys/user_defined.c
+++ b/security/keys/user_defined.c
@@ -30,7 +30,6 @@ struct key_type key_type_user = {
         .free_preparse          = user_free_preparse,
         .instantiate            = generic_key_instantiate,
         .update                 = user_update,
-        .match                  = user_match,
         .revoke                 = user_revoke,
         .destroy                = user_destroy,
         .describe               = user_describe,
@@ -51,7 +50,6 @@ struct key_type key_type_logon = {
         .free_preparse          = user_free_preparse,
         .instantiate            = generic_key_instantiate,
         .update                 = user_update,
-        .match                  = user_match,
         .revoke                 = user_revoke,
         .destroy                = user_destroy,
         .describe               = user_describe,
@@ -137,16 +135,6 @@ error:
 EXPORT_SYMBOL_GPL(user_update);
 
 /*
- * match users on their name
- */
-int user_match(const struct key *key, const struct key_match_data *match_data)
-{
-        return strcmp(key->description, match_data->raw_data) == 0;
-}
-
-EXPORT_SYMBOL_GPL(user_match);
-
-/*
  * dispose of the links from a revoked keyring
  * - called with the key sem write-locked
  */