public_key.c 3.1 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
/* 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");

25
const char *const pkey_algo_name[PKEY_ALGO__LAST] = {
26 27 28
	[PKEY_ALGO_DSA]		= "DSA",
	[PKEY_ALGO_RSA]		= "RSA",
};
29
EXPORT_SYMBOL_GPL(pkey_algo_name);
30

31 32 33 34 35 36 37 38
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);

39
const char *const pkey_id_type_name[PKEY_ID_TYPE__LAST] = {
40 41
	[PKEY_ID_PGP]		= "PGP",
	[PKEY_ID_X509]		= "X509",
42
	[PKEY_ID_PKCS7]		= "PKCS#7",
43
};
44
EXPORT_SYMBOL_GPL(pkey_id_type_name);
45 46 47 48 49 50 51 52 53 54 55

/*
 * 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",
56
			   pkey_id_type_name[key->id_type], key->algo->name);
57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77
}

/*
 * 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.
 */
78 79
int public_key_verify_signature(const struct public_key *pk,
				const struct public_key_signature *sig)
80
{
81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97
	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;
	}
98

99
	if (!algo->verify_signature)
100 101
		return -ENOTSUPP;

102
	if (sig->nr_mpi != algo->n_sig_mpi) {
103
		pr_debug("Signature has %u MPI not %u\n",
104
			 sig->nr_mpi, algo->n_sig_mpi);
105 106 107
		return -EINVAL;
	}

108 109 110 111 112 113 114 115 116
	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);
117 118 119 120 121 122 123 124
}

/*
 * Public key algorithm asymmetric key subtype
 */
struct asymmetric_key_subtype public_key_subtype = {
	.owner			= THIS_MODULE,
	.name			= "public_key",
125
	.name_len		= sizeof("public_key") - 1,
126 127
	.describe		= public_key_describe,
	.destroy		= public_key_destroy,
128
	.verify_signature	= public_key_verify_signature_2,
129 130
};
EXPORT_SYMBOL_GPL(public_key_subtype);
新手
引导
客服 返回
顶部