blob: e2d0edbbc71acd7be8878817b86e53af5a921e04 [file] [log] [blame]
/* Testing module to load key from trusted PKCS#7 message
*
* Copyright (C) 2014 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) "PKCS7key: "fmt
#include <linux/key.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/key-type.h>
#include <keys/asymmetric-type.h>
#include <crypto/pkcs7.h>
#include <keys/user-type.h>
#include <keys/system_keyring.h>
#include "pkcs7_parser.h"
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("PKCS#7 testing key type");
static unsigned pkcs7_usage;
module_param_named(usage, pkcs7_usage, uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(pkcs7_usage,
"Usage to specify when verifying the PKCS#7 message");
/*
* Preparse a PKCS#7 wrapped and validated data blob.
*/
static int pkcs7_preparse(struct key_preparsed_payload *prep)
{
enum key_being_used_for usage = pkcs7_usage;
struct pkcs7_message *pkcs7;
const void *data, *saved_prep_data;
size_t datalen, saved_prep_datalen;
bool trusted;
int ret;
kenter("");
if (usage >= NR__KEY_BEING_USED_FOR) {
pr_err("Invalid usage type %d\n", usage);
return -EINVAL;
}
saved_prep_data = prep->data;
saved_prep_datalen = prep->datalen;
pkcs7 = pkcs7_parse_message(saved_prep_data, saved_prep_datalen);
if (IS_ERR(pkcs7)) {
ret = PTR_ERR(pkcs7);
goto error;
}
ret = pkcs7_verify(pkcs7, usage);
if (ret < 0)
goto error_free;
ret = pkcs7_validate_trust(pkcs7, system_trusted_keyring, &trusted);
if (ret < 0)
goto error_free;
if (!trusted)
pr_warn("PKCS#7 message doesn't chain back to a trusted key\n");
ret = pkcs7_get_content_data(pkcs7, &data, &datalen, false);
if (ret < 0)
goto error_free;
prep->data = data;
prep->datalen = datalen;
ret = user_preparse(prep);
prep->data = saved_prep_data;
prep->datalen = saved_prep_datalen;
error_free:
pkcs7_free_message(pkcs7);
error:
kleave(" = %d", ret);
return ret;
}
/*
* user defined keys take an arbitrary string as the description and an
* arbitrary blob of data as the payload
*/
static struct key_type key_type_pkcs7 = {
.name = "pkcs7_test",
.preparse = pkcs7_preparse,
.free_preparse = user_free_preparse,
.instantiate = generic_key_instantiate,
.revoke = user_revoke,
.destroy = user_destroy,
.describe = user_describe,
.read = user_read,
};
/*
* Module stuff
*/
static int __init pkcs7_key_init(void)
{
return register_key_type(&key_type_pkcs7);
}
static void __exit pkcs7_key_cleanup(void)
{
unregister_key_type(&key_type_pkcs7);
}
module_init(pkcs7_key_init);
module_exit(pkcs7_key_cleanup);