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/*
* 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 <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_SYSTEM_TRUSTED_KEYRING
/*
* Restrict the addition of keys into the IMA keyring.
*
* Any key that needs to go in .ima keyring must be signed by CA in
* either .system or .ima_mok keyrings.
*/
static int restrict_link_by_ima_mok(struct key *keyring,
const struct key_type *type,
unsigned long flags,
const union key_payload *payload)
{
int ret;
ret = restrict_link_by_builtin_trusted(keyring, type, flags, payload);
if (ret != -ENOKEY)
return ret;
return restrict_link_by_signature(get_ima_mok_keyring(),
type, payload);
}
#else
/*
* If there's no system trusted keyring, then keys cannot be loaded into
* .ima_mok and added keys cannot be marked trusted.
*/
#define restrict_link_by_ima_mok restrict_link_reject
#endif
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;
}
int __init integrity_init_keyring(const unsigned int id)
{
const struct cred *cred = current_cred();
int err = 0;
if (!init_keyring)
return 0;
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,
restrict_link_by_ima_mok, 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;
char *data;
int rc;
if (!keyring[id])
return -EINVAL;
rc = integrity_read_file(path, &data);
if (rc < 0)
return rc;
key = key_create_or_update(make_key_ref(keyring[id], 1),
"asymmetric",
NULL,
data,
rc,
((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);
}
kfree(data);
return 0;
}
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