Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Cryptographic API. | |
3 | * | |
4 | * SHA1 Secure Hash Algorithm. | |
5 | * | |
6 | * Derived from cryptoapi implementation, adapted for in-place | |
7 | * scatterlist interface. | |
8 | * | |
9 | * Copyright (c) Alan Smithee. | |
10 | * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk> | |
11 | * Copyright (c) Jean-Francois Dive <jef@linuxbe.org> | |
12 | * | |
13 | * This program is free software; you can redistribute it and/or modify it | |
14 | * under the terms of the GNU General Public License as published by the Free | |
15 | * Software Foundation; either version 2 of the License, or (at your option) | |
16 | * any later version. | |
17 | * | |
18 | */ | |
19 | #include <linux/init.h> | |
20 | #include <linux/module.h> | |
21 | #include <linux/mm.h> | |
22 | #include <linux/crypto.h> | |
23 | #include <linux/cryptohash.h> | |
24 | #include <asm/scatterlist.h> | |
25 | #include <asm/byteorder.h> | |
26 | ||
27 | #define SHA1_DIGEST_SIZE 20 | |
28 | #define SHA1_HMAC_BLOCK_SIZE 64 | |
29 | ||
30 | struct sha1_ctx { | |
31 | u64 count; | |
32 | u32 state[5]; | |
33 | u8 buffer[64]; | |
34 | }; | |
35 | ||
36 | static void sha1_init(void *ctx) | |
37 | { | |
38 | struct sha1_ctx *sctx = ctx; | |
39 | static const struct sha1_ctx initstate = { | |
40 | 0, | |
41 | { 0x67452301, 0xEFCDAB89, 0x98BADCFE, 0x10325476, 0xC3D2E1F0 }, | |
42 | { 0, } | |
43 | }; | |
44 | ||
45 | *sctx = initstate; | |
46 | } | |
47 | ||
48 | static void sha1_update(void *ctx, const u8 *data, unsigned int len) | |
49 | { | |
50 | struct sha1_ctx *sctx = ctx; | |
51 | unsigned int i, j; | |
52 | u32 temp[SHA_WORKSPACE_WORDS]; | |
53 | ||
54 | j = (sctx->count >> 3) & 0x3f; | |
55 | sctx->count += len << 3; | |
56 | ||
57 | if ((j + len) > 63) { | |
58 | memcpy(&sctx->buffer[j], data, (i = 64-j)); | |
59 | sha_transform(sctx->state, sctx->buffer, temp); | |
60 | for ( ; i + 63 < len; i += 64) { | |
61 | sha_transform(sctx->state, &data[i], temp); | |
62 | } | |
63 | j = 0; | |
64 | } | |
65 | else i = 0; | |
66 | memset(temp, 0, sizeof(temp)); | |
67 | memcpy(&sctx->buffer[j], &data[i], len - i); | |
68 | } | |
69 | ||
70 | ||
71 | /* Add padding and return the message digest. */ | |
72 | static void sha1_final(void* ctx, u8 *out) | |
73 | { | |
74 | struct sha1_ctx *sctx = ctx; | |
75 | u32 i, j, index, padlen; | |
76 | u64 t; | |
77 | u8 bits[8] = { 0, }; | |
78 | static const u8 padding[64] = { 0x80, }; | |
79 | ||
80 | t = sctx->count; | |
81 | bits[7] = 0xff & t; t>>=8; | |
82 | bits[6] = 0xff & t; t>>=8; | |
83 | bits[5] = 0xff & t; t>>=8; | |
84 | bits[4] = 0xff & t; t>>=8; | |
85 | bits[3] = 0xff & t; t>>=8; | |
86 | bits[2] = 0xff & t; t>>=8; | |
87 | bits[1] = 0xff & t; t>>=8; | |
88 | bits[0] = 0xff & t; | |
89 | ||
90 | /* Pad out to 56 mod 64 */ | |
91 | index = (sctx->count >> 3) & 0x3f; | |
92 | padlen = (index < 56) ? (56 - index) : ((64+56) - index); | |
93 | sha1_update(sctx, padding, padlen); | |
94 | ||
95 | /* Append length */ | |
96 | sha1_update(sctx, bits, sizeof bits); | |
97 | ||
98 | /* Store state in digest */ | |
99 | for (i = j = 0; i < 5; i++, j += 4) { | |
100 | u32 t2 = sctx->state[i]; | |
101 | out[j+3] = t2 & 0xff; t2>>=8; | |
102 | out[j+2] = t2 & 0xff; t2>>=8; | |
103 | out[j+1] = t2 & 0xff; t2>>=8; | |
104 | out[j ] = t2 & 0xff; | |
105 | } | |
106 | ||
107 | /* Wipe context */ | |
108 | memset(sctx, 0, sizeof *sctx); | |
109 | } | |
110 | ||
111 | static struct crypto_alg alg = { | |
112 | .cra_name = "sha1", | |
113 | .cra_flags = CRYPTO_ALG_TYPE_DIGEST, | |
114 | .cra_blocksize = SHA1_HMAC_BLOCK_SIZE, | |
115 | .cra_ctxsize = sizeof(struct sha1_ctx), | |
116 | .cra_module = THIS_MODULE, | |
117 | .cra_list = LIST_HEAD_INIT(alg.cra_list), | |
118 | .cra_u = { .digest = { | |
119 | .dia_digestsize = SHA1_DIGEST_SIZE, | |
120 | .dia_init = sha1_init, | |
121 | .dia_update = sha1_update, | |
122 | .dia_final = sha1_final } } | |
123 | }; | |
124 | ||
125 | static int __init init(void) | |
126 | { | |
127 | return crypto_register_alg(&alg); | |
128 | } | |
129 | ||
130 | static void __exit fini(void) | |
131 | { | |
132 | crypto_unregister_alg(&alg); | |
133 | } | |
134 | ||
135 | module_init(init); | |
136 | module_exit(fini); | |
137 | ||
138 | MODULE_LICENSE("GPL"); | |
139 | MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm"); |