[linux-block.git] / crypto / asymmetric_keys / pkcs7_key_type.c

// SPDX-License-Identifier: GPL-2.0-or-later
/* 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)
 */

#define pr_fmt(fmt) "PKCS7key: "fmt
#include <linux/key.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/verification.h>
#include <linux/key-type.h>
#include <keys/user-type.h>

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("PKCS#7 testing key type");
MODULE_AUTHOR("Red Hat, Inc.");

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");

/*
 * Retrieve the PKCS#7 message content.
 */
static int pkcs7_view_content(void *ctx, const void *data, size_t len,
			      size_t asn1hdrlen)
{
	struct key_preparsed_payload *prep = ctx;
	const void *saved_prep_data;
	size_t saved_prep_datalen;
	int ret;

	saved_prep_data = prep->data;
	saved_prep_datalen = prep->datalen;
	prep->data = data;
	prep->datalen = len;

	ret = user_preparse(prep);

	prep->data = saved_prep_data;
	prep->datalen = saved_prep_datalen;
	return ret;
}

/*
 * 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;

	if (usage >= NR__KEY_BEING_USED_FOR) {
		pr_err("Invalid usage type %d\n", usage);
		return -EINVAL;
	}

	return verify_pkcs7_signature(NULL, 0,
				      prep->data, prep->datalen,
				      VERIFY_USE_SECONDARY_KEYRING, usage,
				      pkcs7_view_content, prep);
}

/*
 * 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
b4d0d230	1	// SPDX-License-Identifier: GPL-2.0-or-later
22d01afb DH	2	/* Testing module to load key from trusted PKCS#7 message
	3	*
	4	* Copyright (C) 2014 Red Hat, Inc. All Rights Reserved.
	5	* Written by David Howells (dhowells@redhat.com)
22d01afb DH	6	*/
	7
	8	#define pr_fmt(fmt) "PKCS7key: "fmt
	9	#include <linux/key.h>
8f3438cc	10	#include <linux/err.h>
88775588	11	#include <linux/module.h>
e68503bd	12	#include <linux/verification.h>
22d01afb	13	#include <linux/key-type.h>
22d01afb	14	#include <keys/user-type.h>
22d01afb	15
772111ab DH	16	MODULE_LICENSE("GPL");
772111ab DH	17	MODULE_DESCRIPTION("PKCS#7 testing key type");
1e684d38	18	MODULE_AUTHOR("Red Hat, Inc.");
772111ab	19
99db4435 DH	20	static unsigned pkcs7_usage;
	21	module_param_named(usage, pkcs7_usage, uint, S_IWUSR \| S_IRUGO);
	22	MODULE_PARM_DESC(pkcs7_usage,
	23	"Usage to specify when verifying the PKCS#7 message");
	24
22d01afb	25	/*
e68503bd	26	* Retrieve the PKCS#7 message content.
22d01afb	27	*/
e68503bd DH	28	static int pkcs7_view_content(void ctx, const void data, size_t len,
e68503bd DH	29	size_t asn1hdrlen)
22d01afb	30	{
e68503bd DH	31	struct key_preparsed_payload *prep = ctx;
	32	const void *saved_prep_data;
	33	size_t saved_prep_datalen;
22d01afb DH	34	int ret;
22d01afb DH	35
22d01afb DH	36	saved_prep_data = prep->data;
22d01afb DH	37	saved_prep_datalen = prep->datalen;
22d01afb	38	prep->data = data;
e68503bd DH	39	prep->datalen = len;
e68503bd DH	40
1ca72c96	41	ret = user_preparse(prep);
e68503bd	42
22d01afb DH	43	prep->data = saved_prep_data;
22d01afb DH	44	prep->datalen = saved_prep_datalen;
22d01afb DH	45	return ret;
	46	}
	47
e68503bd DH	48	/*
	49	* Preparse a PKCS#7 wrapped and validated data blob.
	50	*/
	51	static int pkcs7_preparse(struct key_preparsed_payload *prep)
	52	{
	53	enum key_being_used_for usage = pkcs7_usage;
	54
	55	if (usage >= NR__KEY_BEING_USED_FOR) {
	56	pr_err("Invalid usage type %d\n", usage);
	57	return -EINVAL;
	58	}
	59
	60	return verify_pkcs7_signature(NULL, 0,
	61	prep->data, prep->datalen,
817aef26	62	VERIFY_USE_SECONDARY_KEYRING, usage,
e68503bd DH	63	pkcs7_view_content, prep);
	64	}
	65
22d01afb DH	66	/*
	67	* user defined keys take an arbitrary string as the description and an
	68	* arbitrary blob of data as the payload
	69	*/
63d2551e	70	static struct key_type key_type_pkcs7 = {
22d01afb	71	.name = "pkcs7_test",
1ca72c96 DH	72	.preparse = pkcs7_preparse,
	73	.free_preparse = user_free_preparse,
	74	.instantiate = generic_key_instantiate,
22d01afb DH	75	.revoke = user_revoke,
	76	.destroy = user_destroy,
	77	.describe = user_describe,
	78	.read = user_read,
	79	};
	80
	81	/*
	82	* Module stuff
	83	*/
	84	static int __init pkcs7_key_init(void)
	85	{
	86	return register_key_type(&key_type_pkcs7);
	87	}
	88
	89	static void __exit pkcs7_key_cleanup(void)
	90	{
	91	unregister_key_type(&key_type_pkcs7);
	92	}
	93
	94	module_init(pkcs7_key_init);
	95	module_exit(pkcs7_key_cleanup);