blob: 1f7d53013a228b4a459470d86ebfc0bb17998239 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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 */
Herbert Xu3631c652007-12-13 22:28:59 +080019
20#include <crypto/internal/skcipher.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070021#include <linux/init.h>
22#include <linux/module.h>
23#include <linux/mm.h>
Patrick McHardyd0856002005-05-16 21:53:41 -070024#include <linux/string.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025
26#define NULL_KEY_SIZE 0
27#define NULL_BLOCK_SIZE 1
28#define NULL_DIGEST_SIZE 0
Herbert Xu3631c652007-12-13 22:28:59 +080029#define NULL_IV_SIZE 0
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
Herbert Xu6c2bb982006-05-16 22:09:29 +100031static int null_compress(struct crypto_tfm *tfm, const u8 *src,
32 unsigned int slen, u8 *dst, unsigned int *dlen)
Patrick McHardyd0856002005-05-16 21:53:41 -070033{
34 if (slen > *dlen)
35 return -EINVAL;
36 memcpy(dst, src, slen);
37 *dlen = slen;
38 return 0;
39}
Linus Torvalds1da177e2005-04-16 15:20:36 -070040
Herbert Xu6c2bb982006-05-16 22:09:29 +100041static void null_init(struct crypto_tfm *tfm)
Linus Torvalds1da177e2005-04-16 15:20:36 -070042{ }
43
Herbert Xu6c2bb982006-05-16 22:09:29 +100044static void null_update(struct crypto_tfm *tfm, const u8 *data,
45 unsigned int len)
Linus Torvalds1da177e2005-04-16 15:20:36 -070046{ }
47
Herbert Xu6c2bb982006-05-16 22:09:29 +100048static void null_final(struct crypto_tfm *tfm, u8 *out)
Linus Torvalds1da177e2005-04-16 15:20:36 -070049{ }
50
Herbert Xu6c2bb982006-05-16 22:09:29 +100051static int null_setkey(struct crypto_tfm *tfm, const u8 *key,
Herbert Xu560c06a2006-08-13 14:16:39 +100052 unsigned int keylen)
Linus Torvalds1da177e2005-04-16 15:20:36 -070053{ return 0; }
54
Herbert Xu6c2bb982006-05-16 22:09:29 +100055static void null_crypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)
Patrick McHardyd0856002005-05-16 21:53:41 -070056{
57 memcpy(dst, src, NULL_BLOCK_SIZE);
58}
Linus Torvalds1da177e2005-04-16 15:20:36 -070059
Herbert Xu3631c652007-12-13 22:28:59 +080060static int skcipher_null_crypt(struct blkcipher_desc *desc,
61 struct scatterlist *dst,
62 struct scatterlist *src, unsigned int nbytes)
63{
64 struct blkcipher_walk walk;
65 int err;
66
67 blkcipher_walk_init(&walk, dst, src, nbytes);
68 err = blkcipher_walk_virt(desc, &walk);
69
70 while (walk.nbytes) {
71 if (walk.src.virt.addr != walk.dst.virt.addr)
72 memcpy(walk.dst.virt.addr, walk.src.virt.addr,
73 walk.nbytes);
74 err = blkcipher_walk_done(desc, &walk, 0);
75 }
76
77 return err;
78}
79
Linus Torvalds1da177e2005-04-16 15:20:36 -070080static struct crypto_alg compress_null = {
81 .cra_name = "compress_null",
82 .cra_flags = CRYPTO_ALG_TYPE_COMPRESS,
83 .cra_blocksize = NULL_BLOCK_SIZE,
84 .cra_ctxsize = 0,
85 .cra_module = THIS_MODULE,
86 .cra_list = LIST_HEAD_INIT(compress_null.cra_list),
87 .cra_u = { .compress = {
88 .coa_compress = null_compress,
Patrick McHardyd0856002005-05-16 21:53:41 -070089 .coa_decompress = null_compress } }
Linus Torvalds1da177e2005-04-16 15:20:36 -070090};
91
92static struct crypto_alg digest_null = {
93 .cra_name = "digest_null",
94 .cra_flags = CRYPTO_ALG_TYPE_DIGEST,
95 .cra_blocksize = NULL_BLOCK_SIZE,
96 .cra_ctxsize = 0,
97 .cra_module = THIS_MODULE,
98 .cra_list = LIST_HEAD_INIT(digest_null.cra_list),
99 .cra_u = { .digest = {
100 .dia_digestsize = NULL_DIGEST_SIZE,
Herbert Xuce5bd4a2007-12-14 00:28:40 +0800101 .dia_setkey = null_setkey,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 .dia_init = null_init,
103 .dia_update = null_update,
104 .dia_final = null_final } }
105};
106
107static struct crypto_alg cipher_null = {
108 .cra_name = "cipher_null",
109 .cra_flags = CRYPTO_ALG_TYPE_CIPHER,
110 .cra_blocksize = NULL_BLOCK_SIZE,
111 .cra_ctxsize = 0,
112 .cra_module = THIS_MODULE,
113 .cra_list = LIST_HEAD_INIT(cipher_null.cra_list),
114 .cra_u = { .cipher = {
115 .cia_min_keysize = NULL_KEY_SIZE,
116 .cia_max_keysize = NULL_KEY_SIZE,
117 .cia_setkey = null_setkey,
Patrick McHardyd0856002005-05-16 21:53:41 -0700118 .cia_encrypt = null_crypt,
119 .cia_decrypt = null_crypt } }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120};
121
Herbert Xu3631c652007-12-13 22:28:59 +0800122static struct crypto_alg skcipher_null = {
123 .cra_name = "ecb(cipher_null)",
124 .cra_driver_name = "ecb-cipher_null",
125 .cra_priority = 100,
126 .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER,
127 .cra_blocksize = NULL_BLOCK_SIZE,
128 .cra_type = &crypto_blkcipher_type,
129 .cra_ctxsize = 0,
130 .cra_module = THIS_MODULE,
131 .cra_list = LIST_HEAD_INIT(skcipher_null.cra_list),
132 .cra_u = { .blkcipher = {
133 .min_keysize = NULL_KEY_SIZE,
134 .max_keysize = NULL_KEY_SIZE,
135 .ivsize = NULL_IV_SIZE,
136 .setkey = null_setkey,
137 .encrypt = skcipher_null_crypt,
138 .decrypt = skcipher_null_crypt } }
139};
140
Linus Torvalds1da177e2005-04-16 15:20:36 -0700141MODULE_ALIAS("compress_null");
142MODULE_ALIAS("digest_null");
143MODULE_ALIAS("cipher_null");
144
Kamalesh Babulal3af5b902008-04-05 21:00:57 +0800145static int __init crypto_null_mod_init(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146{
147 int ret = 0;
148
149 ret = crypto_register_alg(&cipher_null);
150 if (ret < 0)
151 goto out;
152
Herbert Xu3631c652007-12-13 22:28:59 +0800153 ret = crypto_register_alg(&skcipher_null);
154 if (ret < 0)
155 goto out_unregister_cipher;
156
Linus Torvalds1da177e2005-04-16 15:20:36 -0700157 ret = crypto_register_alg(&digest_null);
Herbert Xu3631c652007-12-13 22:28:59 +0800158 if (ret < 0)
159 goto out_unregister_skcipher;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700160
161 ret = crypto_register_alg(&compress_null);
Herbert Xu3631c652007-12-13 22:28:59 +0800162 if (ret < 0)
163 goto out_unregister_digest;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164
165out:
166 return ret;
Herbert Xu3631c652007-12-13 22:28:59 +0800167
168out_unregister_digest:
169 crypto_unregister_alg(&digest_null);
170out_unregister_skcipher:
171 crypto_unregister_alg(&skcipher_null);
172out_unregister_cipher:
173 crypto_unregister_alg(&cipher_null);
174 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175}
176
Kamalesh Babulal3af5b902008-04-05 21:00:57 +0800177static void __exit crypto_null_mod_fini(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178{
179 crypto_unregister_alg(&compress_null);
180 crypto_unregister_alg(&digest_null);
Herbert Xu3631c652007-12-13 22:28:59 +0800181 crypto_unregister_alg(&skcipher_null);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 crypto_unregister_alg(&cipher_null);
183}
184
Kamalesh Babulal3af5b902008-04-05 21:00:57 +0800185module_init(crypto_null_mod_init);
186module_exit(crypto_null_mod_fini);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187
188MODULE_LICENSE("GPL");
189MODULE_DESCRIPTION("Null Cryptographic Algorithms");