[deliverable/linux.git] / crypto / asymmetric_keys / pkcs7_key_type.c

/* 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);
Commit	Line	Data
22d01afb DH	1	/* Testing module to load key from trusted PKCS#7 message
	2	*
	3	* Copyright (C) 2014 Red Hat, Inc. All Rights Reserved.
	4	* Written by David Howells (dhowells@redhat.com)
	5	*
	6	* This program is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU General Public Licence
	8	* as published by the Free Software Foundation; either version
	9	* 2 of the Licence, or (at your option) any later version.
	10	*/
	11
	12	#define pr_fmt(fmt) "PKCS7key: "fmt
	13	#include <linux/key.h>
8f3438cc	14	#include <linux/err.h>
88775588	15	#include <linux/module.h>
22d01afb	16	#include <linux/key-type.h>
99db4435	17	#include <keys/asymmetric-type.h>
22d01afb DH	18	#include <crypto/pkcs7.h>
	19	#include <keys/user-type.h>
	20	#include <keys/system_keyring.h>
	21	#include "pkcs7_parser.h"
	22
772111ab DH	23	MODULE_LICENSE("GPL");
	24	MODULE_DESCRIPTION("PKCS#7 testing key type");
	25
99db4435 DH	26	static unsigned pkcs7_usage;
	27	module_param_named(usage, pkcs7_usage, uint, S_IWUSR \| S_IRUGO);
	28	MODULE_PARM_DESC(pkcs7_usage,
	29	"Usage to specify when verifying the PKCS#7 message");
	30
22d01afb	31	/*
1ca72c96	32	* Preparse a PKCS#7 wrapped and validated data blob.
22d01afb	33	*/
1ca72c96	34	static int pkcs7_preparse(struct key_preparsed_payload *prep)
22d01afb	35	{
99db4435	36	enum key_being_used_for usage = pkcs7_usage;
22d01afb DH	37	struct pkcs7_message *pkcs7;
	38	const void data, saved_prep_data;
	39	size_t datalen, saved_prep_datalen;
	40	bool trusted;
	41	int ret;
	42
	43	kenter("");
	44
99db4435 DH	45	if (usage >= NR__KEY_BEING_USED_FOR) {
	46	pr_err("Invalid usage type %d\n", usage);
	47	return -EINVAL;
	48	}
	49
22d01afb DH	50	saved_prep_data = prep->data;
	51	saved_prep_datalen = prep->datalen;
	52	pkcs7 = pkcs7_parse_message(saved_prep_data, saved_prep_datalen);
	53	if (IS_ERR(pkcs7)) {
	54	ret = PTR_ERR(pkcs7);
	55	goto error;
	56	}
	57
99db4435	58	ret = pkcs7_verify(pkcs7, usage);
22d01afb DH	59	if (ret < 0)
	60	goto error_free;
	61
	62	ret = pkcs7_validate_trust(pkcs7, system_trusted_keyring, &trusted);
	63	if (ret < 0)
	64	goto error_free;
	65	if (!trusted)
	66	pr_warn("PKCS#7 message doesn't chain back to a trusted key\n");
	67
	68	ret = pkcs7_get_content_data(pkcs7, &data, &datalen, false);
	69	if (ret < 0)
	70	goto error_free;
	71
	72	prep->data = data;
	73	prep->datalen = datalen;
1ca72c96	74	ret = user_preparse(prep);
22d01afb DH	75	prep->data = saved_prep_data;
	76	prep->datalen = saved_prep_datalen;
	77
	78	error_free:
	79	pkcs7_free_message(pkcs7);
	80	error:
	81	kleave(" = %d", ret);
	82	return ret;
	83	}
	84
	85	/*
	86	* user defined keys take an arbitrary string as the description and an
	87	* arbitrary blob of data as the payload
	88	*/
63d2551e	89	static struct key_type key_type_pkcs7 = {
22d01afb	90	.name = "pkcs7_test",
1ca72c96 DH	91	.preparse = pkcs7_preparse,
	92	.free_preparse = user_free_preparse,
	93	.instantiate = generic_key_instantiate,
22d01afb DH	94	.revoke = user_revoke,
	95	.destroy = user_destroy,
	96	.describe = user_describe,
	97	.read = user_read,
	98	};
	99
	100	/*
	101	* Module stuff
	102	*/
	103	static int __init pkcs7_key_init(void)
	104	{
	105	return register_key_type(&key_type_pkcs7);
	106	}
	107
	108	static void __exit pkcs7_key_cleanup(void)
	109	{
	110	unregister_key_type(&key_type_pkcs7);
	111	}
	112
	113	module_init(pkcs7_key_init);
	114	module_exit(pkcs7_key_cleanup);