projects/linux·blob v3.13 · refs

156 lines · 3.5 KiB

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 <[email protected]>
11 * Copyright (c) Jean-Francois Dive <[email protected]>
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 <crypto/internal/hash.h>
20#include <linux/init.h>
21#include <linux/module.h>
22#include <linux/mm.h>
23#include <linux/cryptohash.h>
24#include <linux/types.h>
25#include <crypto/sha.h>
26#include <asm/byteorder.h>
27
28static int sha1_init(struct shash_desc *desc)
29{
30 struct sha1_state *sctx = shash_desc_ctx(desc);
31
32 *sctx = (struct sha1_state){
33 .state = { SHA1_H0, SHA1_H1, SHA1_H2, SHA1_H3, SHA1_H4 },
34 };
35
36 return 0;
37}
38
39int crypto_sha1_update(struct shash_desc *desc, const u8 *data,
40 unsigned int len)
41{
42 struct sha1_state *sctx = shash_desc_ctx(desc);
43 unsigned int partial, done;
44 const u8 *src;
45
46 partial = sctx->count % SHA1_BLOCK_SIZE;
47 sctx->count += len;
48 done = 0;
49 src = data;
50
51 if ((partial + len) >= SHA1_BLOCK_SIZE) {
52 u32 temp[SHA_WORKSPACE_WORDS];
53
54 if (partial) {
55 done = -partial;
56 memcpy(sctx->buffer + partial, data,
57 done + SHA1_BLOCK_SIZE);
58 src = sctx->buffer;
59 }
60
61 do {
62 sha_transform(sctx->state, src, temp);
63 done += SHA1_BLOCK_SIZE;
64 src = data + done;
65 } while (done + SHA1_BLOCK_SIZE <= len);
66
67 memset(temp, 0, sizeof(temp));
68 partial = 0;
69 }
70 memcpy(sctx->buffer + partial, src, len - done);
71
72 return 0;
73}
74EXPORT_SYMBOL(crypto_sha1_update);
75
76
77/* Add padding and return the message digest. */
78static int sha1_final(struct shash_desc *desc, u8 *out)
79{
80 struct sha1_state *sctx = shash_desc_ctx(desc);
81 __be32 *dst = (__be32 *)out;
82 u32 i, index, padlen;
83 __be64 bits;
84 static const u8 padding[64] = { 0x80, };
85
86 bits = cpu_to_be64(sctx->count << 3);
87
88 /* Pad out to 56 mod 64 */
89 index = sctx->count & 0x3f;
90 padlen = (index < 56) ? (56 - index) : ((64+56) - index);
91 crypto_sha1_update(desc, padding, padlen);
92
93 /* Append length */
94 crypto_sha1_update(desc, (const u8 *)&bits, sizeof(bits));
95
96 /* Store state in digest */
97 for (i = 0; i < 5; i++)
98 dst[i] = cpu_to_be32(sctx->state[i]);
99
100 /* Wipe context */
101 memset(sctx, 0, sizeof *sctx);
102
103 return 0;
104}
105
106static int sha1_export(struct shash_desc *desc, void *out)
107{
108 struct sha1_state *sctx = shash_desc_ctx(desc);
109
110 memcpy(out, sctx, sizeof(*sctx));
111 return 0;
112}
113
114static int sha1_import(struct shash_desc *desc, const void *in)
115{
116 struct sha1_state *sctx = shash_desc_ctx(desc);
117
118 memcpy(sctx, in, sizeof(*sctx));
119 return 0;
120}
121
122static struct shash_alg alg = {
123 .digestsize = SHA1_DIGEST_SIZE,
124 .init = sha1_init,
125 .update = crypto_sha1_update,
126 .final = sha1_final,
127 .export = sha1_export,
128 .import = sha1_import,
129 .descsize = sizeof(struct sha1_state),
130 .statesize = sizeof(struct sha1_state),
131 .base = {
132 .cra_name = "sha1",
133 .cra_driver_name= "sha1-generic",
134 .cra_flags = CRYPTO_ALG_TYPE_SHASH,
135 .cra_blocksize = SHA1_BLOCK_SIZE,
136 .cra_module = THIS_MODULE,
137 }
138};
139
140static int __init sha1_generic_mod_init(void)
141{
142 return crypto_register_shash(&alg);
143}
144
145static void __exit sha1_generic_mod_fini(void)
146{
147 crypto_unregister_shash(&alg);
148}
149
150module_init(sha1_generic_mod_init);
151module_exit(sha1_generic_mod_fini);
152
153MODULE_LICENSE("GPL");
154MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");
155
156MODULE_ALIAS("sha1");