1 files changed, 58 insertions, 0 deletions
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
new file mode 100644
index 00000000000..b4af4ebc5be
--- /dev/null
+++ b/security/integrity/digsig.c
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2011 Intel Corporation
+ *
+ * Author:
+ * Dmitry Kasatkin <dmitry.kasatkin@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/err.h>
+#include <linux/rbtree.h>
+#include <linux/key-type.h>
+#include <linux/digsig.h>
+
+#include "integrity.h"
+
+static struct key *keyring[INTEGRITY_KEYRING_MAX];
+
+static const char *keyring_name[INTEGRITY_KEYRING_MAX] = {
+	"_evm",
+	"_module",
+	"_ima",
+};
+
+int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
+			    const char *digest, int digestlen)
+{
+	if (id >= INTEGRITY_KEYRING_MAX)
+		return -EINVAL;
+
+	if (!keyring[id]) {
+		keyring[id] =
+			request_key(&key_type_keyring, keyring_name[id], NULL);
+		if (IS_ERR(keyring[id])) {
+			int err = PTR_ERR(keyring[id]);
+			pr_err("no %s keyring: %d\n", keyring_name[id], err);
+			keyring[id] = NULL;
+			return err;
+		}
+	}
+
+	switch (sig[1]) {
+	case 1:
+		/* v1 API expect signature without xattr type */
+		return digsig_verify(keyring[id], sig + 1, siglen - 1,
+				     digest, digestlen);
+	case 2:
+		return asymmetric_verify(keyring[id], sig, siglen,
+					 digest, digestlen);
+	}
+
+	return -EOPNOTSUPP;
+}