[mirror_ubuntu-bionic-kernel.git] / crypto / asymmetric_keys / signature.c

/* Signature verification with an asymmetric key
 *
 * See Documentation/security/asymmetric-keys.txt
 *
 * Copyright (C) 2012 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) "SIG: "fmt
#include <keys/asymmetric-subtype.h>
#include <linux/export.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <crypto/public_key.h>
#include "asymmetric_keys.h"

/*
 * Destroy a public key signature.
 */
void public_key_signature_free(struct public_key_signature *sig)
{
	int i;

	if (sig) {
		for (i = 0; i < ARRAY_SIZE(sig->auth_ids); i++)
			kfree(sig->auth_ids[i]);
		kfree(sig->s);
		kfree(sig->digest);
		kfree(sig);
	}
}
EXPORT_SYMBOL_GPL(public_key_signature_free);

/**
 * verify_signature - Initiate the use of an asymmetric key to verify a signature
 * @key: The asymmetric key to verify against
 * @sig: The signature to check
 *
 * Returns 0 if successful or else an error.
 */
int verify_signature(const struct key *key,
		     const struct public_key_signature *sig)
{
	const struct asymmetric_key_subtype *subtype;
	int ret;

	pr_devel("==>%s()\n", __func__);

	if (key->type != &key_type_asymmetric)
		return -EINVAL;
	subtype = asymmetric_key_subtype(key);
	if (!subtype ||
	    !key->payload.data[0])
		return -EINVAL;
	if (!subtype->verify_signature)
		return -ENOTSUPP;

	ret = subtype->verify_signature(key, sig);

	pr_devel("<==%s() = %d\n", __func__, ret);
	return ret;
}
EXPORT_SYMBOL_GPL(verify_signature);
Commit	Line	Data
4ae71c1d DH	1	/* Signature verification with an asymmetric key
	2	*
	3	* See Documentation/security/asymmetric-keys.txt
	4	*
	5	* Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
	6	* Written by David Howells (dhowells@redhat.com)
	7	*
	8	* This program is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU General Public Licence
	10	* as published by the Free Software Foundation; either version
	11	* 2 of the Licence, or (at your option) any later version.
	12	*/
	13
c3ce6dfa	14	#define pr_fmt(fmt) "SIG: "fmt
4ae71c1d	15	#include <keys/asymmetric-subtype.h>
1f6a9ab0	16	#include <linux/export.h>
4ae71c1d	17	#include <linux/err.h>
3b764563	18	#include <linux/slab.h>
4ae71c1d DH	19	#include <crypto/public_key.h>
	20	#include "asymmetric_keys.h"
	21
3b764563 DH	22	/*
	23	* Destroy a public key signature.
	24	*/
	25	void public_key_signature_free(struct public_key_signature *sig)
	26	{
a022ec02 DH	27	int i;
a022ec02 DH	28
3b764563	29	if (sig) {
a022ec02 DH	30	for (i = 0; i < ARRAY_SIZE(sig->auth_ids); i++)
a022ec02 DH	31	kfree(sig->auth_ids[i]);
3b764563 DH	32	kfree(sig->s);
	33	kfree(sig->digest);
	34	kfree(sig);
	35	}
	36	}
	37	EXPORT_SYMBOL_GPL(public_key_signature_free);
	38
4ae71c1d DH	39	/**
	40	* verify_signature - Initiate the use of an asymmetric key to verify a signature
	41	* @key: The asymmetric key to verify against
	42	* @sig: The signature to check
	43	*
	44	* Returns 0 if successful or else an error.
	45	*/
	46	int verify_signature(const struct key *key,
	47	const struct public_key_signature *sig)
	48	{
	49	const struct asymmetric_key_subtype *subtype;
	50	int ret;
	51
	52	pr_devel("==>%s()\n", __func__);
	53
	54	if (key->type != &key_type_asymmetric)
	55	return -EINVAL;
	56	subtype = asymmetric_key_subtype(key);
	57	if (!subtype \|\|
146aa8b1	58	!key->payload.data[0])
4ae71c1d DH	59	return -EINVAL;
	60	if (!subtype->verify_signature)
	61	return -ENOTSUPP;
	62
	63	ret = subtype->verify_signature(key, sig);
	64
	65	pr_devel("<==%s() = %d\n", __func__, ret);
	66	return ret;
	67	}
	68	EXPORT_SYMBOL_GPL(verify_signature);