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)
19 #include <linux/init.h>
20 #include <linux/module.h>
22 #include <linux/crypto.h>
23 #include <linux/cryptohash.h>
24 #include <linux/types.h>
25 #include <asm/scatterlist.h>
26 #include <asm/byteorder.h>
28 #define SHA1_DIGEST_SIZE 20
29 #define SHA1_HMAC_BLOCK_SIZE 64
37 static void sha1_init(void *ctx)
39 struct sha1_ctx *sctx = ctx;
40 static const struct sha1_ctx initstate = {
42 { 0x67452301, 0xEFCDAB89, 0x98BADCFE, 0x10325476, 0xC3D2E1F0 },
49 static void sha1_update(void *ctx, const u8 *data, unsigned int len)
51 struct sha1_ctx *sctx = ctx;
55 j = (sctx->count >> 3) & 0x3f;
56 sctx->count += len << 3;
61 u32 temp[SHA_WORKSPACE_WORDS];
64 memcpy(&sctx->buffer[j], data, (i = 64-j));
69 sha_transform(sctx->state, src, temp);
72 } while (i + 63 < len);
74 memset(temp, 0, sizeof(temp));
77 memcpy(&sctx->buffer[j], src, len - i);
81 /* Add padding and return the message digest. */
82 static void sha1_final(void* ctx, u8 *out)
84 struct sha1_ctx *sctx = ctx;
85 __be32 *dst = (__be32 *)out;
88 static const u8 padding[64] = { 0x80, };
90 bits = cpu_to_be64(sctx->count);
92 /* Pad out to 56 mod 64 */
93 index = (sctx->count >> 3) & 0x3f;
94 padlen = (index < 56) ? (56 - index) : ((64+56) - index);
95 sha1_update(sctx, padding, padlen);
98 sha1_update(sctx, (const u8 *)&bits, sizeof(bits));
100 /* Store state in digest */
101 for (i = 0; i < 5; i++)
102 dst[i] = cpu_to_be32(sctx->state[i]);
105 memset(sctx, 0, sizeof *sctx);
108 static struct crypto_alg alg = {
110 .cra_flags = CRYPTO_ALG_TYPE_DIGEST,
111 .cra_blocksize = SHA1_HMAC_BLOCK_SIZE,
112 .cra_ctxsize = sizeof(struct sha1_ctx),
113 .cra_module = THIS_MODULE,
114 .cra_list = LIST_HEAD_INIT(alg.cra_list),
115 .cra_u = { .digest = {
116 .dia_digestsize = SHA1_DIGEST_SIZE,
117 .dia_init = sha1_init,
118 .dia_update = sha1_update,
119 .dia_final = sha1_final } }
122 static int __init init(void)
124 return crypto_register_alg(&alg);
127 static void __exit fini(void)
129 crypto_unregister_alg(&alg);
135 MODULE_LICENSE("GPL");
136 MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");