1 files changed, 149 insertions, 0 deletions
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
new file mode 100644
index 000000000..9bb0a7f28
--- /dev/null
+++ b/security/integrity/digsig.c
@@ -0,0 +1,149 @@
+/*
+ * 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/sched.h>
+#include <linux/slab.h>
+#include <linux/cred.h>
+#include <linux/key-type.h>
+#include <linux/digsig.h>
+#include <linux/vmalloc.h>
+#include <crypto/public_key.h>
+#include <keys/system_keyring.h>
+
+#include "integrity.h"
+
+static struct key *keyring[INTEGRITY_KEYRING_MAX];
+
+static const char *keyring_name[INTEGRITY_KEYRING_MAX] = {
+#ifndef CONFIG_INTEGRITY_TRUSTED_KEYRING
+	"_evm",
+	"_ima",
+#else
+	".evm",
+	".ima",
+#endif
+	"_module",
+};
+
+#ifdef CONFIG_INTEGRITY_TRUSTED_KEYRING
+static bool init_keyring __initdata = true;
+#else
+static bool init_keyring __initdata;
+#endif
+
+#ifdef CONFIG_IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
+#define restrict_link_to_ima restrict_link_by_builtin_and_secondary_trusted
+#else
+#define restrict_link_to_ima restrict_link_by_builtin_trusted
+#endif
+
+int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
+			    const char *digest, int digestlen)
+{
+	if (id >= INTEGRITY_KEYRING_MAX || siglen < 2)
+		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;
+}
+
+int __init integrity_init_keyring(const unsigned int id)
+{
+	const struct cred *cred = current_cred();
+	struct key_restriction *restriction;
+	int err = 0;
+
+	if (!init_keyring)
+		return 0;
+
+	restriction = kzalloc(sizeof(struct key_restriction), GFP_KERNEL);
+	if (!restriction)
+		return -ENOMEM;
+
+	restriction->check = restrict_link_to_ima;
+
+	keyring[id] = keyring_alloc(keyring_name[id], KUIDT_INIT(0),
+				    KGIDT_INIT(0), cred,
+				    ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
+				     KEY_USR_VIEW | KEY_USR_READ |
+				     KEY_USR_WRITE | KEY_USR_SEARCH),
+				    KEY_ALLOC_NOT_IN_QUOTA,
+				    restriction, NULL);
+	if (IS_ERR(keyring[id])) {
+		err = PTR_ERR(keyring[id]);
+		pr_info("Can't allocate %s keyring (%d)\n",
+			keyring_name[id], err);
+		keyring[id] = NULL;
+	}
+	return err;
+}
+
+int __init integrity_load_x509(const unsigned int id, const char *path)
+{
+	key_ref_t key;
+	void *data;
+	loff_t size;
+	int rc;
+
+	if (!keyring[id])
+		return -EINVAL;
+
+	rc = kernel_read_file_from_path(path, &data, &size, 0,
+					READING_X509_CERTIFICATE);
+	if (rc < 0) {
+		pr_err("Unable to open file: %s (%d)", path, rc);
+		return rc;
+	}
+
+	key = key_create_or_update(make_key_ref(keyring[id], 1),
+				   "asymmetric",
+				   NULL,
+				   data,
+				   size,
+				   ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
+				    KEY_USR_VIEW | KEY_USR_READ),
+				   KEY_ALLOC_NOT_IN_QUOTA);
+	if (IS_ERR(key)) {
+		rc = PTR_ERR(key);
+		pr_err("Problem loading X.509 certificate (%d): %s\n",
+		       rc, path);
+	} else {
+		pr_notice("Loaded X.509 cert '%s': %s\n",
+			  key_ref_to_ptr(key)->description, path);
+		key_ref_put(key);
+	}
+	vfree(data);
+	return 0;
+}