KEYS: Add a lookup_restriction function for the asymmetric key type

Look up asymmetric keyring restriction information using the key-type
lookup_restrict hook.

Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com>

1 files changed, 44 insertions, 8 deletions

diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c
index 6600181d5d01..2e3380d09631 100644
--- a/crypto/asymmetric_keys/asymmetric_type.c
+++ b/crypto/asymmetric_keys/asymmetric_type.c
@@ -17,6 +17,7 @@
 #include <linux/module.h>
 #include <linux/slab.h>
 #include <linux/ctype.h>
+#include <keys/system_keyring.h>
 #include "asymmetric_keys.h"
 
 MODULE_LICENSE("GPL");
@@ -451,15 +452,50 @@ static void asymmetric_key_destroy(struct key *key)
         asymmetric_key_free_kids(kids);
 }
 
+static struct key_restriction *asymmetric_restriction_alloc(
+        key_restrict_link_func_t check,
+        struct key *key)
+{
+        struct key_restriction *keyres =
+                kzalloc(sizeof(struct key_restriction), GFP_KERNEL);
+
+        if (!keyres)
+                return ERR_PTR(-ENOMEM);
+
+        keyres->check = check;
+        keyres->key = key;
+        keyres->keytype = &key_type_asymmetric;
+
+        return keyres;
+}
+
+/*
+ * look up keyring restrict functions for asymmetric keys
+ */
+static struct key_restriction *asymmetric_lookup_restriction(
+        const char *restriction)
+{
+        if (strcmp("builtin_trusted", restriction) == 0)
+                return asymmetric_restriction_alloc(
+                        restrict_link_by_builtin_trusted, NULL);
+
+        if (strcmp("builtin_and_secondary_trusted", restriction) == 0)
+                return asymmetric_restriction_alloc(
+                        restrict_link_by_builtin_and_secondary_trusted, NULL);
+
+        return ERR_PTR(-EINVAL);
+}
+
 struct key_type key_type_asymmetric = {
-        .name           = "asymmetric",
-        .preparse       = asymmetric_key_preparse,
-        .free_preparse  = asymmetric_key_free_preparse,
-        .instantiate    = generic_key_instantiate,
-        .match_preparse = asymmetric_key_match_preparse,
-        .match_free     = asymmetric_key_match_free,
-        .destroy        = asymmetric_key_destroy,
-        .describe       = asymmetric_key_describe,
+        .name                   = "asymmetric",
+        .preparse               = asymmetric_key_preparse,
+        .free_preparse          = asymmetric_key_free_preparse,
+        .instantiate            = generic_key_instantiate,
+        .match_preparse         = asymmetric_key_match_preparse,
+        .match_free             = asymmetric_key_match_free,
+        .destroy                = asymmetric_key_destroy,
+        .describe               = asymmetric_key_describe,
+        .lookup_restriction     = asymmetric_lookup_restriction,
 };
 EXPORT_SYMBOL_GPL(key_type_asymmetric);