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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> | |
06ace7a9 | 24 | #include <linux/types.h> |
1da177e4 LT |
25 | #include <asm/scatterlist.h> |
26 | #include <asm/byteorder.h> | |
27 | ||
28 | #define SHA1_DIGEST_SIZE 20 | |
29 | #define SHA1_HMAC_BLOCK_SIZE 64 | |
30 | ||
31 | struct sha1_ctx { | |
32 | u64 count; | |
33 | u32 state[5]; | |
34 | u8 buffer[64]; | |
35 | }; | |
36 | ||
37 | static void sha1_init(void *ctx) | |
38 | { | |
39 | struct sha1_ctx *sctx = ctx; | |
40 | static const struct sha1_ctx initstate = { | |
41 | 0, | |
42 | { 0x67452301, 0xEFCDAB89, 0x98BADCFE, 0x10325476, 0xC3D2E1F0 }, | |
43 | { 0, } | |
44 | }; | |
45 | ||
46 | *sctx = initstate; | |
47 | } | |
48 | ||
49 | static void sha1_update(void *ctx, const u8 *data, unsigned int len) | |
50 | { | |
51 | struct sha1_ctx *sctx = ctx; | |
52 | unsigned int i, j; | |
53 | u32 temp[SHA_WORKSPACE_WORDS]; | |
54 | ||
55 | j = (sctx->count >> 3) & 0x3f; | |
56 | sctx->count += len << 3; | |
57 | ||
58 | if ((j + len) > 63) { | |
59 | memcpy(&sctx->buffer[j], data, (i = 64-j)); | |
60 | sha_transform(sctx->state, sctx->buffer, temp); | |
61 | for ( ; i + 63 < len; i += 64) { | |
62 | sha_transform(sctx->state, &data[i], temp); | |
63 | } | |
64 | j = 0; | |
65 | } | |
66 | else i = 0; | |
67 | memset(temp, 0, sizeof(temp)); | |
68 | memcpy(&sctx->buffer[j], &data[i], len - i); | |
69 | } | |
70 | ||
71 | ||
72 | /* Add padding and return the message digest. */ | |
73 | static void sha1_final(void* ctx, u8 *out) | |
74 | { | |
75 | struct sha1_ctx *sctx = ctx; | |
06ace7a9 HX |
76 | __be32 *dst = (__be32 *)out; |
77 | u32 i, index, padlen; | |
78 | __be64 bits; | |
1da177e4 LT |
79 | static const u8 padding[64] = { 0x80, }; |
80 | ||
06ace7a9 | 81 | bits = cpu_to_be64(sctx->count); |
1da177e4 LT |
82 | |
83 | /* Pad out to 56 mod 64 */ | |
84 | index = (sctx->count >> 3) & 0x3f; | |
85 | padlen = (index < 56) ? (56 - index) : ((64+56) - index); | |
86 | sha1_update(sctx, padding, padlen); | |
87 | ||
88 | /* Append length */ | |
06ace7a9 | 89 | sha1_update(sctx, (const u8 *)&bits, sizeof(bits)); |
1da177e4 LT |
90 | |
91 | /* Store state in digest */ | |
06ace7a9 HX |
92 | for (i = 0; i < 5; i++) |
93 | dst[i] = cpu_to_be32(sctx->state[i]); | |
1da177e4 LT |
94 | |
95 | /* Wipe context */ | |
96 | memset(sctx, 0, sizeof *sctx); | |
97 | } | |
98 | ||
99 | static struct crypto_alg alg = { | |
100 | .cra_name = "sha1", | |
101 | .cra_flags = CRYPTO_ALG_TYPE_DIGEST, | |
102 | .cra_blocksize = SHA1_HMAC_BLOCK_SIZE, | |
103 | .cra_ctxsize = sizeof(struct sha1_ctx), | |
104 | .cra_module = THIS_MODULE, | |
105 | .cra_list = LIST_HEAD_INIT(alg.cra_list), | |
106 | .cra_u = { .digest = { | |
107 | .dia_digestsize = SHA1_DIGEST_SIZE, | |
108 | .dia_init = sha1_init, | |
109 | .dia_update = sha1_update, | |
110 | .dia_final = sha1_final } } | |
111 | }; | |
112 | ||
113 | static int __init init(void) | |
114 | { | |
115 | return crypto_register_alg(&alg); | |
116 | } | |
117 | ||
118 | static void __exit fini(void) | |
119 | { | |
120 | crypto_unregister_alg(&alg); | |
121 | } | |
122 | ||
123 | module_init(init); | |
124 | module_exit(fini); | |
125 | ||
126 | MODULE_LICENSE("GPL"); | |
127 | MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm"); |