Linux 2.6.28.1
[linux/fpc-iii.git] / crypto / sha1_generic.c
blobc7c6899e1fca8efb0ce9af81c42747f180203ed7
1 /*
2 * Cryptographic API.
4 * SHA1 Secure Hash Algorithm.
6 * Derived from cryptoapi implementation, adapted for in-place
7 * scatterlist interface.
9 * Copyright (c) Alan Smithee.
10 * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
11 * Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
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.
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 <linux/types.h>
25 #include <crypto/sha.h>
26 #include <asm/byteorder.h>
28 struct sha1_ctx {
29 u64 count;
30 u32 state[5];
31 u8 buffer[64];
34 static void sha1_init(struct crypto_tfm *tfm)
36 struct sha1_ctx *sctx = crypto_tfm_ctx(tfm);
37 static const struct sha1_ctx initstate = {
39 { SHA1_H0, SHA1_H1, SHA1_H2, SHA1_H3, SHA1_H4 },
40 { 0, }
43 *sctx = initstate;
46 static void sha1_update(struct crypto_tfm *tfm, const u8 *data,
47 unsigned int len)
49 struct sha1_ctx *sctx = crypto_tfm_ctx(tfm);
50 unsigned int partial, done;
51 const u8 *src;
53 partial = sctx->count & 0x3f;
54 sctx->count += len;
55 done = 0;
56 src = data;
58 if ((partial + len) > 63) {
59 u32 temp[SHA_WORKSPACE_WORDS];
61 if (partial) {
62 done = -partial;
63 memcpy(sctx->buffer + partial, data, done + 64);
64 src = sctx->buffer;
67 do {
68 sha_transform(sctx->state, src, temp);
69 done += 64;
70 src = data + done;
71 } while (done + 63 < len);
73 memset(temp, 0, sizeof(temp));
74 partial = 0;
76 memcpy(sctx->buffer + partial, src, len - done);
80 /* Add padding and return the message digest. */
81 static void sha1_final(struct crypto_tfm *tfm, u8 *out)
83 struct sha1_ctx *sctx = crypto_tfm_ctx(tfm);
84 __be32 *dst = (__be32 *)out;
85 u32 i, index, padlen;
86 __be64 bits;
87 static const u8 padding[64] = { 0x80, };
89 bits = cpu_to_be64(sctx->count << 3);
91 /* Pad out to 56 mod 64 */
92 index = sctx->count & 0x3f;
93 padlen = (index < 56) ? (56 - index) : ((64+56) - index);
94 sha1_update(tfm, padding, padlen);
96 /* Append length */
97 sha1_update(tfm, (const u8 *)&bits, sizeof(bits));
99 /* Store state in digest */
100 for (i = 0; i < 5; i++)
101 dst[i] = cpu_to_be32(sctx->state[i]);
103 /* Wipe context */
104 memset(sctx, 0, sizeof *sctx);
107 static struct crypto_alg alg = {
108 .cra_name = "sha1",
109 .cra_driver_name= "sha1-generic",
110 .cra_flags = CRYPTO_ALG_TYPE_DIGEST,
111 .cra_blocksize = SHA1_BLOCK_SIZE,
112 .cra_ctxsize = sizeof(struct sha1_ctx),
113 .cra_module = THIS_MODULE,
114 .cra_alignmask = 3,
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 } }
123 static int __init sha1_generic_mod_init(void)
125 return crypto_register_alg(&alg);
128 static void __exit sha1_generic_mod_fini(void)
130 crypto_unregister_alg(&alg);
133 module_init(sha1_generic_mod_init);
134 module_exit(sha1_generic_mod_fini);
136 MODULE_LICENSE("GPL");
137 MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");
139 MODULE_ALIAS("sha1");