Commit | Line | Data |
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1da177e4 LT |
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 | */ | |
3631c650 HX |
19 | |
20 | #include <crypto/internal/skcipher.h> | |
1da177e4 LT |
21 | #include <linux/init.h> |
22 | #include <linux/module.h> | |
23 | #include <linux/mm.h> | |
d0856009 | 24 | #include <linux/string.h> |
1da177e4 LT |
25 | |
26 | #define NULL_KEY_SIZE 0 | |
27 | #define NULL_BLOCK_SIZE 1 | |
28 | #define NULL_DIGEST_SIZE 0 | |
3631c650 | 29 | #define NULL_IV_SIZE 0 |
1da177e4 | 30 | |
6c2bb98b HX |
31 | static int null_compress(struct crypto_tfm *tfm, const u8 *src, |
32 | unsigned int slen, u8 *dst, unsigned int *dlen) | |
d0856009 PM |
33 | { |
34 | if (slen > *dlen) | |
35 | return -EINVAL; | |
36 | memcpy(dst, src, slen); | |
37 | *dlen = slen; | |
38 | return 0; | |
39 | } | |
1da177e4 | 40 | |
6c2bb98b | 41 | static void null_init(struct crypto_tfm *tfm) |
1da177e4 LT |
42 | { } |
43 | ||
6c2bb98b HX |
44 | static void null_update(struct crypto_tfm *tfm, const u8 *data, |
45 | unsigned int len) | |
1da177e4 LT |
46 | { } |
47 | ||
6c2bb98b | 48 | static void null_final(struct crypto_tfm *tfm, u8 *out) |
1da177e4 LT |
49 | { } |
50 | ||
6c2bb98b | 51 | static int null_setkey(struct crypto_tfm *tfm, const u8 *key, |
560c06ae | 52 | unsigned int keylen) |
1da177e4 LT |
53 | { return 0; } |
54 | ||
6c2bb98b | 55 | static void null_crypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) |
d0856009 PM |
56 | { |
57 | memcpy(dst, src, NULL_BLOCK_SIZE); | |
58 | } | |
1da177e4 | 59 | |
3631c650 HX |
60 | static 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 | ||
1da177e4 LT |
80 | static 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, | |
d0856009 | 89 | .coa_decompress = null_compress } } |
1da177e4 LT |
90 | }; |
91 | ||
92 | static 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, | |
101 | .dia_init = null_init, | |
102 | .dia_update = null_update, | |
103 | .dia_final = null_final } } | |
104 | }; | |
105 | ||
106 | static struct crypto_alg cipher_null = { | |
107 | .cra_name = "cipher_null", | |
108 | .cra_flags = CRYPTO_ALG_TYPE_CIPHER, | |
109 | .cra_blocksize = NULL_BLOCK_SIZE, | |
110 | .cra_ctxsize = 0, | |
111 | .cra_module = THIS_MODULE, | |
112 | .cra_list = LIST_HEAD_INIT(cipher_null.cra_list), | |
113 | .cra_u = { .cipher = { | |
114 | .cia_min_keysize = NULL_KEY_SIZE, | |
115 | .cia_max_keysize = NULL_KEY_SIZE, | |
116 | .cia_setkey = null_setkey, | |
d0856009 PM |
117 | .cia_encrypt = null_crypt, |
118 | .cia_decrypt = null_crypt } } | |
1da177e4 LT |
119 | }; |
120 | ||
3631c650 HX |
121 | static struct crypto_alg skcipher_null = { |
122 | .cra_name = "ecb(cipher_null)", | |
123 | .cra_driver_name = "ecb-cipher_null", | |
124 | .cra_priority = 100, | |
125 | .cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER, | |
126 | .cra_blocksize = NULL_BLOCK_SIZE, | |
127 | .cra_type = &crypto_blkcipher_type, | |
128 | .cra_ctxsize = 0, | |
129 | .cra_module = THIS_MODULE, | |
130 | .cra_list = LIST_HEAD_INIT(skcipher_null.cra_list), | |
131 | .cra_u = { .blkcipher = { | |
132 | .min_keysize = NULL_KEY_SIZE, | |
133 | .max_keysize = NULL_KEY_SIZE, | |
134 | .ivsize = NULL_IV_SIZE, | |
135 | .setkey = null_setkey, | |
136 | .encrypt = skcipher_null_crypt, | |
137 | .decrypt = skcipher_null_crypt } } | |
138 | }; | |
139 | ||
1da177e4 LT |
140 | MODULE_ALIAS("compress_null"); |
141 | MODULE_ALIAS("digest_null"); | |
142 | MODULE_ALIAS("cipher_null"); | |
143 | ||
144 | static int __init init(void) | |
145 | { | |
146 | int ret = 0; | |
147 | ||
148 | ret = crypto_register_alg(&cipher_null); | |
149 | if (ret < 0) | |
150 | goto out; | |
151 | ||
3631c650 HX |
152 | ret = crypto_register_alg(&skcipher_null); |
153 | if (ret < 0) | |
154 | goto out_unregister_cipher; | |
155 | ||
1da177e4 | 156 | ret = crypto_register_alg(&digest_null); |
3631c650 HX |
157 | if (ret < 0) |
158 | goto out_unregister_skcipher; | |
1da177e4 LT |
159 | |
160 | ret = crypto_register_alg(&compress_null); | |
3631c650 HX |
161 | if (ret < 0) |
162 | goto out_unregister_digest; | |
1da177e4 LT |
163 | |
164 | out: | |
165 | return ret; | |
3631c650 HX |
166 | |
167 | out_unregister_digest: | |
168 | crypto_unregister_alg(&digest_null); | |
169 | out_unregister_skcipher: | |
170 | crypto_unregister_alg(&skcipher_null); | |
171 | out_unregister_cipher: | |
172 | crypto_unregister_alg(&cipher_null); | |
173 | goto out; | |
1da177e4 LT |
174 | } |
175 | ||
176 | static void __exit fini(void) | |
177 | { | |
178 | crypto_unregister_alg(&compress_null); | |
179 | crypto_unregister_alg(&digest_null); | |
3631c650 | 180 | crypto_unregister_alg(&skcipher_null); |
1da177e4 LT |
181 | crypto_unregister_alg(&cipher_null); |
182 | } | |
183 | ||
184 | module_init(init); | |
185 | module_exit(fini); | |
186 | ||
187 | MODULE_LICENSE("GPL"); | |
188 | MODULE_DESCRIPTION("Null Cryptographic Algorithms"); |