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 | */ | |
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> | |
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 | |
29 | ||
6c2bb98b HX |
30 | static int null_compress(struct crypto_tfm *tfm, const u8 *src, |
31 | unsigned int slen, u8 *dst, unsigned int *dlen) | |
d0856009 PM |
32 | { |
33 | if (slen > *dlen) | |
34 | return -EINVAL; | |
35 | memcpy(dst, src, slen); | |
36 | *dlen = slen; | |
37 | return 0; | |
38 | } | |
1da177e4 | 39 | |
6c2bb98b | 40 | static void null_init(struct crypto_tfm *tfm) |
1da177e4 LT |
41 | { } |
42 | ||
6c2bb98b HX |
43 | static void null_update(struct crypto_tfm *tfm, const u8 *data, |
44 | unsigned int len) | |
1da177e4 LT |
45 | { } |
46 | ||
6c2bb98b | 47 | static void null_final(struct crypto_tfm *tfm, u8 *out) |
1da177e4 LT |
48 | { } |
49 | ||
6c2bb98b | 50 | static int null_setkey(struct crypto_tfm *tfm, const u8 *key, |
560c06ae | 51 | unsigned int keylen) |
1da177e4 LT |
52 | { return 0; } |
53 | ||
6c2bb98b | 54 | static void null_crypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src) |
d0856009 PM |
55 | { |
56 | memcpy(dst, src, NULL_BLOCK_SIZE); | |
57 | } | |
1da177e4 LT |
58 | |
59 | static struct crypto_alg compress_null = { | |
60 | .cra_name = "compress_null", | |
61 | .cra_flags = CRYPTO_ALG_TYPE_COMPRESS, | |
62 | .cra_blocksize = NULL_BLOCK_SIZE, | |
63 | .cra_ctxsize = 0, | |
64 | .cra_module = THIS_MODULE, | |
65 | .cra_list = LIST_HEAD_INIT(compress_null.cra_list), | |
66 | .cra_u = { .compress = { | |
67 | .coa_compress = null_compress, | |
d0856009 | 68 | .coa_decompress = null_compress } } |
1da177e4 LT |
69 | }; |
70 | ||
71 | static struct crypto_alg digest_null = { | |
72 | .cra_name = "digest_null", | |
73 | .cra_flags = CRYPTO_ALG_TYPE_DIGEST, | |
74 | .cra_blocksize = NULL_BLOCK_SIZE, | |
75 | .cra_ctxsize = 0, | |
76 | .cra_module = THIS_MODULE, | |
77 | .cra_list = LIST_HEAD_INIT(digest_null.cra_list), | |
78 | .cra_u = { .digest = { | |
79 | .dia_digestsize = NULL_DIGEST_SIZE, | |
80 | .dia_init = null_init, | |
81 | .dia_update = null_update, | |
82 | .dia_final = null_final } } | |
83 | }; | |
84 | ||
85 | static struct crypto_alg cipher_null = { | |
86 | .cra_name = "cipher_null", | |
87 | .cra_flags = CRYPTO_ALG_TYPE_CIPHER, | |
88 | .cra_blocksize = NULL_BLOCK_SIZE, | |
89 | .cra_ctxsize = 0, | |
90 | .cra_module = THIS_MODULE, | |
91 | .cra_list = LIST_HEAD_INIT(cipher_null.cra_list), | |
92 | .cra_u = { .cipher = { | |
93 | .cia_min_keysize = NULL_KEY_SIZE, | |
94 | .cia_max_keysize = NULL_KEY_SIZE, | |
95 | .cia_setkey = null_setkey, | |
d0856009 PM |
96 | .cia_encrypt = null_crypt, |
97 | .cia_decrypt = null_crypt } } | |
1da177e4 LT |
98 | }; |
99 | ||
100 | MODULE_ALIAS("compress_null"); | |
101 | MODULE_ALIAS("digest_null"); | |
102 | MODULE_ALIAS("cipher_null"); | |
103 | ||
104 | static int __init init(void) | |
105 | { | |
106 | int ret = 0; | |
107 | ||
108 | ret = crypto_register_alg(&cipher_null); | |
109 | if (ret < 0) | |
110 | goto out; | |
111 | ||
112 | ret = crypto_register_alg(&digest_null); | |
113 | if (ret < 0) { | |
114 | crypto_unregister_alg(&cipher_null); | |
115 | goto out; | |
116 | } | |
117 | ||
118 | ret = crypto_register_alg(&compress_null); | |
119 | if (ret < 0) { | |
120 | crypto_unregister_alg(&digest_null); | |
121 | crypto_unregister_alg(&cipher_null); | |
122 | goto out; | |
123 | } | |
124 | ||
125 | out: | |
126 | return ret; | |
127 | } | |
128 | ||
129 | static void __exit fini(void) | |
130 | { | |
131 | crypto_unregister_alg(&compress_null); | |
132 | crypto_unregister_alg(&digest_null); | |
133 | crypto_unregister_alg(&cipher_null); | |
134 | } | |
135 | ||
136 | module_init(init); | |
137 | module_exit(fini); | |
138 | ||
139 | MODULE_LICENSE("GPL"); | |
140 | MODULE_DESCRIPTION("Null Cryptographic Algorithms"); |