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authorDmitry Kasatkin <dmitry.kasatkin@intel.com>2011-10-05 11:54:46 +0300
committerDmitry Kasatkin <dmitry.kasatkin@intel.com>2011-11-09 16:51:09 +0200
commit8607c501478432b23654739c7321bc7456053cb6 (patch)
tree598ef1649a261954cb1cafc05189ddedb3bd3ff8 /security/integrity/digsig.c
parent051dbb918c7fb7da8e64a2cd0d804ba73399709f (diff)
downloadlinux-8607c501478432b23654739c7321bc7456053cb6.tar.bz2
integrity: digital signature verification using multiple keyrings
Define separate keyrings for each of the different use cases - evm, ima, and modules. Using different keyrings improves search performance, and also allows "locking" specific keyring to prevent adding new keys. This is useful for evm and module keyrings, when keys are usually only added from initramfs. Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Diffstat (limited to 'security/integrity/digsig.c')
-rw-r--r--security/integrity/digsig.c48
1 files changed, 48 insertions, 0 deletions
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
new file mode 100644
index 000000000000..2dc167d7cde9
--- /dev/null
+++ b/security/integrity/digsig.c
@@ -0,0 +1,48 @@
+/*
+ * 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;
+ }
+ }
+
+ return digsig_verify(keyring[id], sig, siglen, digest, digestlen);
+}