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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; | |
9d70a6c8 | 52 | unsigned int partial, done; |
cfa8d17c | 53 | const u8 *src; |
1da177e4 | 54 | |
fa9b98fd NP |
55 | partial = sctx->count & 0x3f; |
56 | sctx->count += len; | |
9d70a6c8 | 57 | done = 0; |
cfa8d17c | 58 | src = data; |
1da177e4 | 59 | |
9d70a6c8 | 60 | if ((partial + len) > 63) { |
cfa8d17c NP |
61 | u32 temp[SHA_WORKSPACE_WORDS]; |
62 | ||
9d70a6c8 | 63 | if (partial) { |
bcb0ad2b HX |
64 | done = -partial; |
65 | memcpy(sctx->buffer + partial, data, done + 64); | |
cfa8d17c | 66 | src = sctx->buffer; |
1da177e4 | 67 | } |
cfa8d17c NP |
68 | |
69 | do { | |
70 | sha_transform(sctx->state, src, temp); | |
9d70a6c8 NP |
71 | done += 64; |
72 | src = data + done; | |
73 | } while (done + 63 < len); | |
cfa8d17c NP |
74 | |
75 | memset(temp, 0, sizeof(temp)); | |
9d70a6c8 | 76 | partial = 0; |
1da177e4 | 77 | } |
9d70a6c8 | 78 | memcpy(sctx->buffer + partial, src, len - done); |
1da177e4 LT |
79 | } |
80 | ||
81 | ||
82 | /* Add padding and return the message digest. */ | |
83 | static void sha1_final(void* ctx, u8 *out) | |
84 | { | |
85 | struct sha1_ctx *sctx = ctx; | |
06ace7a9 HX |
86 | __be32 *dst = (__be32 *)out; |
87 | u32 i, index, padlen; | |
88 | __be64 bits; | |
1da177e4 LT |
89 | static const u8 padding[64] = { 0x80, }; |
90 | ||
fa9b98fd | 91 | bits = cpu_to_be64(sctx->count << 3); |
1da177e4 LT |
92 | |
93 | /* Pad out to 56 mod 64 */ | |
fa9b98fd | 94 | index = sctx->count & 0x3f; |
1da177e4 LT |
95 | padlen = (index < 56) ? (56 - index) : ((64+56) - index); |
96 | sha1_update(sctx, padding, padlen); | |
97 | ||
98 | /* Append length */ | |
06ace7a9 | 99 | sha1_update(sctx, (const u8 *)&bits, sizeof(bits)); |
1da177e4 LT |
100 | |
101 | /* Store state in digest */ | |
06ace7a9 HX |
102 | for (i = 0; i < 5; i++) |
103 | dst[i] = cpu_to_be32(sctx->state[i]); | |
1da177e4 LT |
104 | |
105 | /* Wipe context */ | |
106 | memset(sctx, 0, sizeof *sctx); | |
107 | } | |
108 | ||
109 | static struct crypto_alg alg = { | |
110 | .cra_name = "sha1", | |
111 | .cra_flags = CRYPTO_ALG_TYPE_DIGEST, | |
112 | .cra_blocksize = SHA1_HMAC_BLOCK_SIZE, | |
113 | .cra_ctxsize = sizeof(struct sha1_ctx), | |
114 | .cra_module = THIS_MODULE, | |
115 | .cra_list = LIST_HEAD_INIT(alg.cra_list), | |
116 | .cra_u = { .digest = { | |
117 | .dia_digestsize = SHA1_DIGEST_SIZE, | |
118 | .dia_init = sha1_init, | |
119 | .dia_update = sha1_update, | |
120 | .dia_final = sha1_final } } | |
121 | }; | |
122 | ||
123 | static int __init init(void) | |
124 | { | |
125 | return crypto_register_alg(&alg); | |
126 | } | |
127 | ||
128 | static void __exit fini(void) | |
129 | { | |
130 | crypto_unregister_alg(&alg); | |
131 | } | |
132 | ||
133 | module_init(init); | |
134 | module_exit(fini); | |
135 | ||
136 | MODULE_LICENSE("GPL"); | |
137 | MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm"); |