Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/*
2 * Cryptographic API.
3 *
4 * Null algorithms, aka Much Ado About Nothing.
5 *
6 * These are needed for IPsec, and may be useful in general for
7 * testing & debugging.
8 *
9 * The null cipher is compliant with RFC2410.
10 *
11 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
12 *
13 * This program is free software; you can redistribute it and/or modify
14 * it under the terms of the GNU General Public License as published by
15 * the Free Software Foundation; either version 2 of the License, or
16 * (at your option) any later version.
17 *
18 */
19#include <linux/init.h>
20#include <linux/module.h>
21#include <linux/mm.h>
22#include <asm/scatterlist.h>
23#include <linux/crypto.h>
24
25#define NULL_KEY_SIZE 0
26#define NULL_BLOCK_SIZE 1
27#define NULL_DIGEST_SIZE 0
28
29static int null_compress(void *ctx, const u8 *src, unsigned int slen,
30 u8 *dst, unsigned int *dlen)
31{ return 0; }
32
33static int null_decompress(void *ctx, const u8 *src, unsigned int slen,
34 u8 *dst, unsigned int *dlen)
35{ return 0; }
36
37static void null_init(void *ctx)
38{ }
39
40static void null_update(void *ctx, const u8 *data, unsigned int len)
41{ }
42
43static void null_final(void *ctx, u8 *out)
44{ }
45
46static int null_setkey(void *ctx, const u8 *key,
47 unsigned int keylen, u32 *flags)
48{ return 0; }
49
50static void null_encrypt(void *ctx, u8 *dst, const u8 *src)
51{ }
52
53static void null_decrypt(void *ctx, u8 *dst, const u8 *src)
54{ }
55
56static struct crypto_alg compress_null = {
57 .cra_name = "compress_null",
58 .cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
59 .cra_blocksize = NULL_BLOCK_SIZE,
60 .cra_ctxsize = 0,
61 .cra_module = THIS_MODULE,
62 .cra_list = LIST_HEAD_INIT(compress_null.cra_list),
63 .cra_u = { .compress = {
64 .coa_compress = null_compress,
65 .coa_decompress = null_decompress } }
66};
67
68static struct crypto_alg digest_null = {
69 .cra_name = "digest_null",
70 .cra_flags = CRYPTO_ALG_TYPE_DIGEST,
71 .cra_blocksize = NULL_BLOCK_SIZE,
72 .cra_ctxsize = 0,
73 .cra_module = THIS_MODULE,
74 .cra_list = LIST_HEAD_INIT(digest_null.cra_list),
75 .cra_u = { .digest = {
76 .dia_digestsize = NULL_DIGEST_SIZE,
77 .dia_init = null_init,
78 .dia_update = null_update,
79 .dia_final = null_final } }
80};
81
82static struct crypto_alg cipher_null = {
83 .cra_name = "cipher_null",
84 .cra_flags = CRYPTO_ALG_TYPE_CIPHER,
85 .cra_blocksize = NULL_BLOCK_SIZE,
86 .cra_ctxsize = 0,
87 .cra_module = THIS_MODULE,
88 .cra_list = LIST_HEAD_INIT(cipher_null.cra_list),
89 .cra_u = { .cipher = {
90 .cia_min_keysize = NULL_KEY_SIZE,
91 .cia_max_keysize = NULL_KEY_SIZE,
92 .cia_setkey = null_setkey,
93 .cia_encrypt = null_encrypt,
94 .cia_decrypt = null_decrypt } }
95};
96
97MODULE_ALIAS("compress_null");
98MODULE_ALIAS("digest_null");
99MODULE_ALIAS("cipher_null");
100
101static int __init init(void)
102{
103 int ret = 0;
104
105 ret = crypto_register_alg(&cipher_null);
106 if (ret < 0)
107 goto out;
108
109 ret = crypto_register_alg(&digest_null);
110 if (ret < 0) {
111 crypto_unregister_alg(&cipher_null);
112 goto out;
113 }
114
115 ret = crypto_register_alg(&compress_null);
116 if (ret < 0) {
117 crypto_unregister_alg(&digest_null);
118 crypto_unregister_alg(&cipher_null);
119 goto out;
120 }
121
122out:
123 return ret;
124}
125
126static void __exit fini(void)
127{
128 crypto_unregister_alg(&compress_null);
129 crypto_unregister_alg(&digest_null);
130 crypto_unregister_alg(&cipher_null);
131}
132
133module_init(init);
134module_exit(fini);
135
136MODULE_LICENSE("GPL");
137MODULE_DESCRIPTION("Null Cryptographic Algorithms");