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-rw-r--r--kernel/crypto/asymmetric_keys/signature.c50
1 files changed, 50 insertions, 0 deletions
diff --git a/kernel/crypto/asymmetric_keys/signature.c b/kernel/crypto/asymmetric_keys/signature.c
new file mode 100644
index 000000000..7525fd183
--- /dev/null
+++ b/kernel/crypto/asymmetric_keys/signature.c
@@ -0,0 +1,50 @@
+/* Signature verification with an asymmetric key
+ *
+ * See Documentation/security/asymmetric-keys.txt
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt) "SIG: "fmt
+#include <keys/asymmetric-subtype.h>
+#include <linux/module.h>
+#include <linux/err.h>
+#include <crypto/public_key.h>
+#include "asymmetric_keys.h"
+
+/**
+ * verify_signature - Initiate the use of an asymmetric key to verify a signature
+ * @key: The asymmetric key to verify against
+ * @sig: The signature to check
+ *
+ * Returns 0 if successful or else an error.
+ */
+int verify_signature(const struct key *key,
+ const struct public_key_signature *sig)
+{
+ const struct asymmetric_key_subtype *subtype;
+ int ret;
+
+ pr_devel("==>%s()\n", __func__);
+
+ if (key->type != &key_type_asymmetric)
+ return -EINVAL;
+ subtype = asymmetric_key_subtype(key);
+ if (!subtype ||
+ !key->payload.data)
+ return -EINVAL;
+ if (!subtype->verify_signature)
+ return -ENOTSUPP;
+
+ ret = subtype->verify_signature(key, sig);
+
+ pr_devel("<==%s() = %d\n", __func__, ret);
+ return ret;
+}
+EXPORT_SYMBOL_GPL(verify_signature);