summaryrefslogtreecommitdiff
path: root/crypto/crypto_null.c
blob: a0d956b529498c84ea39f2888e63878d143adc6c (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
/* 
 * Cryptographic API.
 *
 * Null algorithms, aka Much Ado About Nothing.
 *
 * These are needed for IPsec, and may be useful in general for
 * testing & debugging.
 * 
 * The null cipher is compliant with RFC2410.
 *
 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mm.h>
#include <asm/scatterlist.h>
#include <linux/crypto.h>
#include <linux/string.h>

#define NULL_KEY_SIZE		0
#define NULL_BLOCK_SIZE		1
#define NULL_DIGEST_SIZE	0

static int null_compress(struct crypto_tfm *tfm, const u8 *src,
			 unsigned int slen, u8 *dst, unsigned int *dlen)
{
	if (slen > *dlen)
		return -EINVAL;
	memcpy(dst, src, slen);
	*dlen = slen;
	return 0;
}

static void null_init(struct crypto_tfm *tfm)
{ }

static void null_update(struct crypto_tfm *tfm, const u8 *data,
			unsigned int len)
{ }

static void null_final(struct crypto_tfm *tfm, u8 *out)
{ }

static int null_setkey(struct crypto_tfm *tfm, const u8 *key,
		       unsigned int keylen, u32 *flags)
{ return 0; }

static void null_crypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
{
	memcpy(dst, src, NULL_BLOCK_SIZE);
}

static struct crypto_alg compress_null = {
	.cra_name		=	"compress_null",
	.cra_flags		=	CRYPTO_ALG_TYPE_COMPRESS,
	.cra_blocksize		=	NULL_BLOCK_SIZE,
	.cra_ctxsize		=	0,
	.cra_module		=	THIS_MODULE,
	.cra_list		=       LIST_HEAD_INIT(compress_null.cra_list),
	.cra_u			=	{ .compress = {
	.coa_compress 		=	null_compress,
	.coa_decompress		=	null_compress } }
};

static struct crypto_alg digest_null = {
	.cra_name		=	"digest_null",
	.cra_flags		=	CRYPTO_ALG_TYPE_DIGEST,
	.cra_blocksize		=	NULL_BLOCK_SIZE,
	.cra_ctxsize		=	0,
	.cra_module		=	THIS_MODULE,
	.cra_list		=       LIST_HEAD_INIT(digest_null.cra_list),	
	.cra_u			=	{ .digest = {
	.dia_digestsize		=	NULL_DIGEST_SIZE,
	.dia_init   		=	null_init,
	.dia_update 		=	null_update,
	.dia_final  		=	null_final } }
};

static struct crypto_alg cipher_null = {
	.cra_name		=	"cipher_null",
	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
	.cra_blocksize		=	NULL_BLOCK_SIZE,
	.cra_ctxsize		=	0,
	.cra_module		=	THIS_MODULE,
	.cra_list		=	LIST_HEAD_INIT(cipher_null.cra_list),
	.cra_u			=	{ .cipher = {
	.cia_min_keysize	=	NULL_KEY_SIZE,
	.cia_max_keysize	=	NULL_KEY_SIZE,
	.cia_setkey		= 	null_setkey,
	.cia_encrypt		=	null_crypt,
	.cia_decrypt		=	null_crypt } }
};

MODULE_ALIAS("compress_null");
MODULE_ALIAS("digest_null");
MODULE_ALIAS("cipher_null");

static int __init init(void)
{
	int ret = 0;
	
	ret = crypto_register_alg(&cipher_null);
	if (ret < 0)
		goto out;

	ret = crypto_register_alg(&digest_null);
	if (ret < 0) {
		crypto_unregister_alg(&cipher_null);
		goto out;
	}

	ret = crypto_register_alg(&compress_null);
	if (ret < 0) {
		crypto_unregister_alg(&digest_null);
		crypto_unregister_alg(&cipher_null);
		goto out;
	}

out:	
	return ret;
}

static void __exit fini(void)
{
	crypto_unregister_alg(&compress_null);
	crypto_unregister_alg(&digest_null);
	crypto_unregister_alg(&cipher_null);
}

module_init(init);
module_exit(fini);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Null Cryptographic Algorithms");