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

/* In-software asymmetric public-key crypto subtype
 *
 * See Documentation/crypto/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) "PKEY: "fmt
#include <linux/module.h>
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <keys/asymmetric-subtype.h>
#include "public_key.h"

MODULE_LICENSE("GPL");

const char *const pkey_algo_name[PKEY_ALGO__LAST] = {
	[PKEY_ALGO_DSA]		= "DSA",
	[PKEY_ALGO_RSA]		= "RSA",
};
EXPORT_SYMBOL_GPL(pkey_algo_name);

const struct public_key_algorithm *pkey_algo[PKEY_ALGO__LAST] = {
#if defined(CONFIG_PUBLIC_KEY_ALGO_RSA) || \
	defined(CONFIG_PUBLIC_KEY_ALGO_RSA_MODULE)
	[PKEY_ALGO_RSA]		= &RSA_public_key_algorithm,
#endif
};
EXPORT_SYMBOL_GPL(pkey_algo);

const char *const pkey_id_type_name[PKEY_ID_TYPE__LAST] = {
	[PKEY_ID_PGP]		= "PGP",
	[PKEY_ID_X509]		= "X509",
	[PKEY_ID_PKCS7]		= "PKCS#7",
};
EXPORT_SYMBOL_GPL(pkey_id_type_name);

/*
 * Provide a part of a description of the key for /proc/keys.
 */
static void public_key_describe(const struct key *asymmetric_key,
				struct seq_file *m)
{
	struct public_key *key = asymmetric_key->payload.data;

	if (key)
		seq_printf(m, "%s.%s",
			   pkey_id_type_name[key->id_type], key->algo->name);
}

/*
 * Destroy a public key algorithm key.
 */
void public_key_destroy(void *payload)
{
	struct public_key *key = payload;
	int i;

	if (key) {
		for (i = 0; i < ARRAY_SIZE(key->mpi); i++)
			mpi_free(key->mpi[i]);
		kfree(key);
	}
}
EXPORT_SYMBOL_GPL(public_key_destroy);

/*
 * Verify a signature using a public key.
 */
int public_key_verify_signature(const struct public_key *pk,
				const struct public_key_signature *sig)
{
	const struct public_key_algorithm *algo;

	BUG_ON(!pk);
	BUG_ON(!pk->mpi[0]);
	BUG_ON(!pk->mpi[1]);
	BUG_ON(!sig);
	BUG_ON(!sig->digest);
	BUG_ON(!sig->mpi[0]);

	algo = pk->algo;
	if (!algo) {
		if (pk->pkey_algo >= PKEY_ALGO__LAST)
			return -ENOPKG;
		algo = pkey_algo[pk->pkey_algo];
		if (!algo)
			return -ENOPKG;
	}

	if (!algo->verify_signature)
		return -ENOTSUPP;

	if (sig->nr_mpi != algo->n_sig_mpi) {
		pr_debug("Signature has %u MPI not %u\n",
			 sig->nr_mpi, algo->n_sig_mpi);
		return -EINVAL;
	}

	return algo->verify_signature(pk, sig);
}
EXPORT_SYMBOL_GPL(public_key_verify_signature);

static int public_key_verify_signature_2(const struct key *key,
					 const struct public_key_signature *sig)
{
	const struct public_key *pk = key->payload.data;
	return public_key_verify_signature(pk, sig);
}

/*
 * Public key algorithm asymmetric key subtype
 */
struct asymmetric_key_subtype public_key_subtype = {
	.owner			= THIS_MODULE,
	.name			= "public_key",
	.name_len		= sizeof("public_key") - 1,
	.describe		= public_key_describe,
	.destroy		= public_key_destroy,
	.verify_signature	= public_key_verify_signature_2,
};
EXPORT_SYMBOL_GPL(public_key_subtype);
Commit	Line	Data
a9681bf3 DH	1	/* In-software asymmetric public-key crypto subtype
	2	*
	3	* See Documentation/crypto/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
	14	#define pr_fmt(fmt) "PKEY: "fmt
	15	#include <linux/module.h>
	16	#include <linux/export.h>
	17	#include <linux/kernel.h>
	18	#include <linux/slab.h>
	19	#include <linux/seq_file.h>
	20	#include <keys/asymmetric-subtype.h>
	21	#include "public_key.h"
	22
	23	MODULE_LICENSE("GPL");
	24
9abc4e66	25	const char *const pkey_algo_name[PKEY_ALGO__LAST] = {
a9681bf3 DH	26	[PKEY_ALGO_DSA] = "DSA",
	27	[PKEY_ALGO_RSA] = "RSA",
	28	};
9abc4e66	29	EXPORT_SYMBOL_GPL(pkey_algo_name);
a9681bf3	30
206ce59a DH	31	const struct public_key_algorithm *pkey_algo[PKEY_ALGO__LAST] = {
	32	#if defined(CONFIG_PUBLIC_KEY_ALGO_RSA) \|\| \
	33	defined(CONFIG_PUBLIC_KEY_ALGO_RSA_MODULE)
	34	[PKEY_ALGO_RSA] = &RSA_public_key_algorithm,
	35	#endif
	36	};
	37	EXPORT_SYMBOL_GPL(pkey_algo);
	38
9abc4e66	39	const char *const pkey_id_type_name[PKEY_ID_TYPE__LAST] = {
a9681bf3 DH	40	[PKEY_ID_PGP] = "PGP",
a9681bf3 DH	41	[PKEY_ID_X509] = "X509",
f29299b4	42	[PKEY_ID_PKCS7] = "PKCS#7",
a9681bf3	43	};
9abc4e66	44	EXPORT_SYMBOL_GPL(pkey_id_type_name);
a9681bf3 DH	45
	46	/*
	47	* Provide a part of a description of the key for /proc/keys.
	48	*/
	49	static void public_key_describe(const struct key *asymmetric_key,
	50	struct seq_file *m)
	51	{
	52	struct public_key *key = asymmetric_key->payload.data;
	53
	54	if (key)
	55	seq_printf(m, "%s.%s",
9abc4e66	56	pkey_id_type_name[key->id_type], key->algo->name);
a9681bf3 DH	57	}
	58
	59	/*
	60	* Destroy a public key algorithm key.
	61	*/
	62	void public_key_destroy(void *payload)
	63	{
	64	struct public_key *key = payload;
	65	int i;
	66
	67	if (key) {
	68	for (i = 0; i < ARRAY_SIZE(key->mpi); i++)
	69	mpi_free(key->mpi[i]);
	70	kfree(key);
	71	}
	72	}
	73	EXPORT_SYMBOL_GPL(public_key_destroy);
	74
	75	/*
	76	* Verify a signature using a public key.
	77	*/
3d167d68 DH	78	int public_key_verify_signature(const struct public_key *pk,
3d167d68 DH	79	const struct public_key_signature *sig)
a9681bf3	80	{
3d167d68 DH	81	const struct public_key_algorithm *algo;
	82
	83	BUG_ON(!pk);
	84	BUG_ON(!pk->mpi[0]);
	85	BUG_ON(!pk->mpi[1]);
	86	BUG_ON(!sig);
	87	BUG_ON(!sig->digest);
	88	BUG_ON(!sig->mpi[0]);
	89
	90	algo = pk->algo;
	91	if (!algo) {
	92	if (pk->pkey_algo >= PKEY_ALGO__LAST)
	93	return -ENOPKG;
	94	algo = pkey_algo[pk->pkey_algo];
	95	if (!algo)
	96	return -ENOPKG;
	97	}
a9681bf3	98
3d167d68	99	if (!algo->verify_signature)
a9681bf3 DH	100	return -ENOTSUPP;
a9681bf3 DH	101
3d167d68	102	if (sig->nr_mpi != algo->n_sig_mpi) {
a9681bf3	103	pr_debug("Signature has %u MPI not %u\n",
3d167d68	104	sig->nr_mpi, algo->n_sig_mpi);
a9681bf3 DH	105	return -EINVAL;
	106	}
	107
3d167d68 DH	108	return algo->verify_signature(pk, sig);
	109	}
	110	EXPORT_SYMBOL_GPL(public_key_verify_signature);
	111
	112	static int public_key_verify_signature_2(const struct key *key,
	113	const struct public_key_signature *sig)
	114	{
	115	const struct public_key *pk = key->payload.data;
	116	return public_key_verify_signature(pk, sig);
a9681bf3 DH	117	}
	118
	119	/*
	120	* Public key algorithm asymmetric key subtype
	121	*/
	122	struct asymmetric_key_subtype public_key_subtype = {
	123	.owner = THIS_MODULE,
	124	.name = "public_key",
876c6e3e	125	.name_len = sizeof("public_key") - 1,
a9681bf3 DH	126	.describe = public_key_describe,
a9681bf3 DH	127	.destroy = public_key_destroy,
3d167d68	128	.verify_signature = public_key_verify_signature_2,
a9681bf3 DH	129	};
a9681bf3 DH	130	EXPORT_SYMBOL_GPL(public_key_subtype);