11 files changed, 129 insertions, 51 deletions

diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c
index eb8cd46961a5..f666b4e8d256 100644
--- a/crypto/asymmetric_keys/asymmetric_type.c
+++ b/crypto/asymmetric_keys/asymmetric_type.c
@@ -59,9 +59,11 @@ EXPORT_SYMBOL_GPL(asymmetric_keyid_match);
  *      "id:<id>"       - request a key matching the ID
  *      "<subtype>:<id>" - request a key of a subtype
  */
-static int asymmetric_key_match(const struct key *key, const void *description)
+static int asymmetric_key_match(const struct key *key,
+                                const struct key_match_data *match_data)
 {
         const struct asymmetric_key_subtype *subtype = asymmetric_key_subtype(key);
+        const char *description = match_data->raw_data;
         const char *spec = description;
         const char *id;
         ptrdiff_t speclen;
@@ -94,6 +96,31 @@ static int asymmetric_key_match(const struct key *key, const void *description)
 }
 
 /*
+ * Preparse the match criterion.  If we don't set lookup_type and cmp,
+ * the default will be an exact match on the key description.
+ *
+ * There are some specifiers for matching key IDs rather than by the key
+ * description:
+ *
+ *      "id:<id>" - request a key by any available ID
+ *
+ * These have to be searched by iteration rather than by direct lookup because
+ * the key is hashed according to its description.
+ */
+static int asymmetric_key_match_preparse(struct key_match_data *match_data)
+{
+        match_data->lookup_type = KEYRING_SEARCH_LOOKUP_ITERATE;
+        return 0;
+}
+
+/*
+ * Free the preparsed the match criterion.
+ */
+static void asymmetric_key_match_free(struct key_match_data *match_data)
+{
+}
+
+/*
  * Describe the asymmetric key
  */
 static void asymmetric_key_describe(const struct key *key, struct seq_file *m)
@@ -196,7 +223,9 @@ struct key_type key_type_asymmetric = {
         .preparse       = asymmetric_key_preparse,
         .free_preparse  = asymmetric_key_free_preparse,
         .instantiate    = generic_key_instantiate,
+        .match_preparse = asymmetric_key_match_preparse,
         .match          = asymmetric_key_match,
+        .match_free     = asymmetric_key_match_free,
         .destroy        = asymmetric_key_destroy,
         .describe       = asymmetric_key_describe,
         .def_lookup_type = KEYRING_SEARCH_LOOKUP_ITERATE,
diff --git a/include/keys/user-type.h b/include/keys/user-type.h
index 3ab1873a4bfa..66d92af30e7c 100644
--- a/include/keys/user-type.h
+++ b/include/keys/user-type.h
@@ -36,11 +36,13 @@ extern struct key_type key_type_user;
 extern struct key_type key_type_logon;
 
 struct key_preparsed_payload;
+struct key_match_data;
 
 extern int user_preparse(struct key_preparsed_payload *prep);
 extern void user_free_preparse(struct key_preparsed_payload *prep);
 extern int user_update(struct key *key, struct key_preparsed_payload *prep);
-extern int user_match(const struct key *key, const void *criterion);
+extern int user_match(const struct key *key,
+                      const struct key_match_data *match_data);
 extern void user_revoke(struct key *key);
 extern void user_destroy(struct key *key);
 extern void user_describe(const struct key *user, struct seq_file *m);
diff --git a/include/linux/key-type.h b/include/linux/key-type.h
index 44792ee649de..8aba688a451a 100644
--- a/include/linux/key-type.h
+++ b/include/linux/key-type.h
@@ -53,6 +53,22 @@ typedef int (*request_key_actor_t)(struct key_construction *key,
                                    const char *op, void *aux);
 
 /*
+ * Preparsed matching criterion.
+ */
+struct key_match_data {
+        /* Comparison function, defaults to type->match, but can be replaced by
+         * type->match_preparse(). */
+        int (*cmp)(const struct key *key,
+                   const struct key_match_data *match_data);
+
+        const void      *raw_data;      /* Raw match data */
+        void            *preparsed;     /* For ->match_preparse() to stash stuff */
+        unsigned        lookup_type;    /* Type of lookup for this search. */
+#define KEYRING_SEARCH_LOOKUP_DIRECT    0x0000  /* Direct lookup by description. */
+#define KEYRING_SEARCH_LOOKUP_ITERATE   0x0001  /* Iterative search. */
+};
+
+/*
  * kernel managed key type definition
  */
 struct key_type {
@@ -67,8 +83,6 @@ struct key_type {
 
         /* Default key search algorithm. */
         unsigned def_lookup_type;
-#define KEYRING_SEARCH_LOOKUP_DIRECT    0x0000  /* Direct lookup by description. */
-#define KEYRING_SEARCH_LOOKUP_ITERATE   0x0001  /* Iterative search. */
 
         /* vet a description */
         int (*vet_description)(const char *description);
@@ -96,8 +110,19 @@ struct key_type {
          */
         int (*update)(struct key *key, struct key_preparsed_payload *prep);
 
+        /* Preparse the data supplied to ->match() (optional).  The
+         * data to be preparsed can be found in match_data->raw_data.
+         * The lookup type can also be set by this function.
+         */
+        int (*match_preparse)(struct key_match_data *match_data);
+
         /* match a key against a description */
-        int (*match)(const struct key *key, const void *desc);
+        int (*match)(const struct key *key,
+                     const struct key_match_data *match_data);
+
+        /* Free preparsed match data (optional).  This should be supplied it
+         * ->match_preparse() is supplied. */
+        void (*match_free)(struct key_match_data *match_data);
 
         /* clear some of the data from a key on revokation (optional)
          * - the key's semaphore will be write-locked by the caller
diff --git a/net/dns_resolver/dns_key.c b/net/dns_resolver/dns_key.c
index f380b2c58178..92df6e508ae7 100644
--- a/net/dns_resolver/dns_key.c
+++ b/net/dns_resolver/dns_key.c
@@ -177,10 +177,11 @@ static void dns_resolver_free_preparse(struct key_preparsed_payload *prep)
  * should end with a period).  The domain name is case-independent.
  */
 static int
-dns_resolver_match(const struct key *key, const void *description)
+dns_resolver_match(const struct key *key,
+                   const struct key_match_data *match_data)
 {
         int slen, dlen, ret = 0;
-        const char *src = key->description, *dsp = description;
+        const char *src = key->description, *dsp = match_data->raw_data;
 
         kenter("%s,%s", src, dsp);
 
diff --git a/security/keys/internal.h b/security/keys/internal.h
index 5f20da01fd8d..805e60b0b87e 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -107,13 +107,10 @@ extern int iterate_over_keyring(const struct key *keyring,
                                 int (*func)(const struct key *key, void *data),
                                 void *data);
 
-typedef int (*key_match_func_t)(const struct key *, const void *);
-
 struct keyring_search_context {
         struct keyring_index_key index_key;
         const struct cred       *cred;
-        key_match_func_t        match;
-        const void              *match_data;
+        struct key_match_data   match_data;
         unsigned                flags;
 #define KEYRING_SEARCH_LOOKUP_TYPE      0x0001  /* [as type->def_lookup_type] */
 #define KEYRING_SEARCH_NO_STATE_CHECK   0x0002  /* Skip state checks */
@@ -152,7 +149,8 @@ extern struct key *request_key_and_link(struct key_type *type,
                                         struct key *dest_keyring,
                                         unsigned long flags);
 
-extern int lookup_user_key_possessed(const struct key *key, const void *target);
+extern int lookup_user_key_possessed(const struct key *key,
+                                     const struct key_match_data *match_data);
 extern key_ref_t lookup_user_key(key_serial_t id, unsigned long flags,
                                  key_perm_t perm);
 #define KEY_LOOKUP_CREATE       0x01
diff --git a/security/keys/keyring.c b/security/keys/keyring.c
index 8314a7d2104d..10f0a5f2d362 100644
--- a/security/keys/keyring.c
+++ b/security/keys/keyring.c
@@ -545,7 +545,7 @@ static int keyring_search_iterator(const void *object, void *iterator_data)
         }
 
         /* keys that don't match */
-        if (!ctx->match(key, ctx->match_data)) {
+        if (!ctx->match_data.cmp(key, &ctx->match_data)) {
                 kleave(" = 0 [!match]");
                 return 0;
         }
@@ -585,8 +585,7 @@ skipped:
  */
 static int search_keyring(struct key *keyring, struct keyring_search_context *ctx)
 {
-        if ((ctx->flags & KEYRING_SEARCH_LOOKUP_TYPE) ==
-            KEYRING_SEARCH_LOOKUP_DIRECT) {
+        if (ctx->match_data.lookup_type == KEYRING_SEARCH_LOOKUP_DIRECT) {
                 const void *object;
 
                 object = assoc_array_find(&keyring->keys,
@@ -627,7 +626,7 @@ static bool search_nested_keyrings(struct key *keyring,
         /* Check to see if this top-level keyring is what we are looking for
          * and whether it is valid or not.
          */
-        if (ctx->flags & KEYRING_SEARCH_LOOKUP_ITERATE ||
+        if (ctx->match_data.lookup_type == KEYRING_SEARCH_LOOKUP_ITERATE ||
             keyring_compare_object(keyring, &ctx->index_key)) {
                 ctx->skipped_ret = 2;
                 ctx->flags |= KEYRING_SEARCH_DO_STATE_CHECK;
@@ -885,16 +884,28 @@ key_ref_t keyring_search(key_ref_t keyring,
                 .index_key.type         = type,
                 .index_key.description  = description,
                 .cred                   = current_cred(),
-                .match                  = type->match,
-                .match_data             = description,
-                .flags                  = (type->def_lookup_type |
-                                           KEYRING_SEARCH_DO_STATE_CHECK),
+                .match_data.cmp         = type->match,
+                .match_data.raw_data    = description,
+                .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
+                .flags                  = KEYRING_SEARCH_DO_STATE_CHECK,
         };
+        key_ref_t key;
+        int ret;
 
-        if (!ctx.match)
+        if (!ctx.match_data.cmp)
                 return ERR_PTR(-ENOKEY);
 
-        return keyring_search_aux(keyring, &ctx);
+        if (type->match_preparse) {
+                ret = type->match_preparse(&ctx.match_data);
+                if (ret < 0)
+                        return ERR_PTR(ret);
+        }
+
+        key = keyring_search_aux(keyring, &ctx);
+
+        if (type->match_free)
+                type->match_free(&ctx.match_data);
+        return key;
 }
 EXPORT_SYMBOL(keyring_search);
 
@@ -1014,7 +1025,7 @@ static int keyring_detect_cycle_iterator(const void *object,
 
         /* We might get a keyring with matching index-key that is nonetheless a
          * different keyring. */
-        if (key != ctx->match_data)
+        if (key != ctx->match_data.raw_data)
                 return 0;
 
         ctx->result = ERR_PTR(-EDEADLK);
@@ -1031,14 +1042,14 @@ static int keyring_detect_cycle_iterator(const void *object,
 static int keyring_detect_cycle(struct key *A, struct key *B)
 {
         struct keyring_search_context ctx = {
-                .index_key      = A->index_key,
-                .match_data     = A,
-                .iterator       = keyring_detect_cycle_iterator,
-                .flags          = (KEYRING_SEARCH_LOOKUP_DIRECT |
-                                   KEYRING_SEARCH_NO_STATE_CHECK |
-                                   KEYRING_SEARCH_NO_UPDATE_TIME |
-                                   KEYRING_SEARCH_NO_CHECK_PERM |
-                                   KEYRING_SEARCH_DETECT_TOO_DEEP),
+                .index_key              = A->index_key,
+                .match_data.raw_data    = A,
+                .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
+                .iterator               = keyring_detect_cycle_iterator,
+                .flags                  = (KEYRING_SEARCH_NO_STATE_CHECK |
+                                           KEYRING_SEARCH_NO_UPDATE_TIME |
+                                           KEYRING_SEARCH_NO_CHECK_PERM |
+                                           KEYRING_SEARCH_DETECT_TOO_DEEP),
         };
 
         rcu_read_lock();
diff --git a/security/keys/proc.c b/security/keys/proc.c
index d3f6f2fd21db..972eeb336b81 100644
--- a/security/keys/proc.c
+++ b/security/keys/proc.c
@@ -194,10 +194,10 @@ static int proc_keys_show(struct seq_file *m, void *v)
                 .index_key.type         = key->type,
                 .index_key.description  = key->description,
                 .cred                   = current_cred(),
-                .match                  = lookup_user_key_possessed,
-                .match_data             = key,
-                .flags                  = (KEYRING_SEARCH_NO_STATE_CHECK |
-                                           KEYRING_SEARCH_LOOKUP_DIRECT),
+                .match_data.cmp         = lookup_user_key_possessed,
+                .match_data.raw_data    = key,
+                .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
+                .flags                  = KEYRING_SEARCH_NO_STATE_CHECK,
         };
 
         key_ref = make_key_ref(key, 0);
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index 0cf8a130a267..08bd533d014f 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -489,9 +489,10 @@ found:
 /*
  * See if the key we're looking at is the target key.
  */
-int lookup_user_key_possessed(const struct key *key, const void *target)
+int lookup_user_key_possessed(const struct key *key,
+                              const struct key_match_data *match_data)
 {
-        return key == target;
+        return key == match_data->raw_data;
 }
 
 /*
@@ -516,9 +517,9 @@ key_ref_t lookup_user_key(key_serial_t id, unsigned long lflags,
                           key_perm_t perm)
 {
         struct keyring_search_context ctx = {
-                .match  = lookup_user_key_possessed,
-                .flags  = (KEYRING_SEARCH_NO_STATE_CHECK |
-                           KEYRING_SEARCH_LOOKUP_DIRECT),
+                .match_data.cmp         = lookup_user_key_possessed,
+                .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
+                .flags                  = KEYRING_SEARCH_NO_STATE_CHECK,
         };
         struct request_key_auth *rka;
         struct key *key;
@@ -673,7 +674,7 @@ try_again:
                 ctx.index_key.type              = key->type;
                 ctx.index_key.description       = key->description;
                 ctx.index_key.desc_len          = strlen(key->description);
-                ctx.match_data                  = key;
+                ctx.match_data.raw_data         = key;
                 kdebug("check possessed");
                 skey_ref = search_process_keyrings(&ctx);
                 kdebug("possessed=%p", skey_ref);
diff --git a/security/keys/request_key.c b/security/keys/request_key.c
index 381411941cc1..408523e5e2e2 100644
--- a/security/keys/request_key.c
+++ b/security/keys/request_key.c
@@ -531,9 +531,9 @@ struct key *request_key_and_link(struct key_type *type,
                 .index_key.type         = type,
                 .index_key.description  = description,
                 .cred                   = current_cred(),
-                .match                  = type->match,
-                .match_data             = description,
-                .flags                  = KEYRING_SEARCH_LOOKUP_DIRECT,
+                .match_data.cmp         = type->match,
+                .match_data.raw_data    = description,
+                .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
         };
         struct key *key;
         key_ref_t key_ref;
@@ -543,6 +543,14 @@ struct key *request_key_and_link(struct key_type *type,
                ctx.index_key.type->name, ctx.index_key.description,
                callout_info, callout_len, aux, dest_keyring, flags);
 
+        if (type->match_preparse) {
+                ret = type->match_preparse(&ctx.match_data);
+                if (ret < 0) {
+                        key = ERR_PTR(ret);
+                        goto error;
+                }
+        }
+
         /* search all the process keyrings for a key */
         key_ref = search_process_keyrings(&ctx);
 
@@ -555,7 +563,7 @@ struct key *request_key_and_link(struct key_type *type,
                         if (ret < 0) {
                                 key_put(key);
                                 key = ERR_PTR(ret);
-                                goto error;
+                                goto error_free;
                         }
                 }
         } else if (PTR_ERR(key_ref) != -EAGAIN) {
@@ -565,12 +573,15 @@ struct key *request_key_and_link(struct key_type *type,
                  * should consult userspace if we can */
                 key = ERR_PTR(-ENOKEY);
                 if (!callout_info)
-                        goto error;
+                        goto error_free;
 
                 key = construct_key_and_link(&ctx, callout_info, callout_len,
                                              aux, dest_keyring, flags);
         }
 
+error_free:
+        if (type->match_free)
+                type->match_free(&ctx.match_data);
 error:
         kleave(" = %p", key);
         return key;
diff --git a/security/keys/request_key_auth.c b/security/keys/request_key_auth.c
index 739e7455d388..9ae02819cc06 100644
--- a/security/keys/request_key_auth.c
+++ b/security/keys/request_key_auth.c
@@ -246,9 +246,9 @@ 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                  = user_match,
-                .match_data             = description,
-                .flags                  = KEYRING_SEARCH_LOOKUP_DIRECT,
+                .match_data.cmp         = user_match,
+                .match_data.raw_data    = description,
+                .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT,
         };
         struct key *authkey;
         key_ref_t authkey_ref;
diff --git a/security/keys/user_defined.c b/security/keys/user_defined.c
index eee340011f2b..ec8a56063b02 100644
--- a/security/keys/user_defined.c
+++ b/security/keys/user_defined.c
@@ -141,9 +141,9 @@ EXPORT_SYMBOL_GPL(user_update);
 /*
  * match users on their name
  */
-int user_match(const struct key *key, const void *description)
+int user_match(const struct key *key, const struct key_match_data *match_data)
 {
-        return strcmp(key->description, description) == 0;
+        return strcmp(key->description, match_data->raw_data) == 0;
 }
 
 EXPORT_SYMBOL_GPL(user_match);