1 files changed, 94 insertions, 8 deletions
diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c
index 6600181d5d01..e4b0ed386bc8 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 +452,100 @@ 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)
+{
+	char *restrict_method;
+	char *parse_buf;
+	char *next;
+	struct key_restriction *ret = ERR_PTR(-EINVAL);
+
+	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);
+
+	parse_buf = kstrndup(restriction, PAGE_SIZE, GFP_KERNEL);
+	if (!parse_buf)
+		return ERR_PTR(-ENOMEM);
+
+	next = parse_buf;
+	restrict_method = strsep(&next, ":");
+
+	if ((strcmp(restrict_method, "key_or_keyring") == 0) && next) {
+		char *key_text;
+		key_serial_t serial;
+		struct key *key;
+		key_restrict_link_func_t link_fn =
+			restrict_link_by_key_or_keyring;
+		bool allow_null_key = false;
+
+		key_text = strsep(&next, ":");
+
+		if (next) {
+			if (strcmp(next, "chain") != 0)
+				goto out;
+
+			link_fn = restrict_link_by_key_or_keyring_chain;
+			allow_null_key = true;
+		}
+
+		if (kstrtos32(key_text, 0, &serial) < 0)
+			goto out;
+
+		if ((serial == 0) && allow_null_key) {
+			key = NULL;
+		} else {
+			key = key_lookup(serial);
+			if (IS_ERR(key)) {
+				ret = ERR_CAST(key);
+				goto out;
+			}
+		}
+
+		ret = asymmetric_restriction_alloc(link_fn, key);
+		if (IS_ERR(ret))
+			key_put(key);
+	}
+
+out:
+	kfree(parse_buf);
+	return ret;
+}
+
 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);