LXR linux-old/crypto/sha1.c

   1/*
   2 * Cryptographic API.
   3 *
   4 * SHA1 Secure Hash Algorithm.
   5 *
   6 * Derived from cryptoapi implementation, adapted for in-place
   7 * scatterlist interface.  Originally based on the public domain
   8 * implementation written by Steve Reid.
   9 *
  10 * Copyright (c) Alan Smithee.
  11 * Copyright (c) Andrew McDonald <andrew@mcdonald.org.uk>
  12 * Copyright (c) Jean-Francois Dive <jef@linuxbe.org>
  13 *
  14 * This program is free software; you can redistribute it and/or modify it
  15 * under the terms of the GNU General Public License as published by the Free
  16 * Software Foundation; either version 2 of the License, or (at your option) 
  17 * any later version.
  18 *
  19 */
  20#include <linux/init.h>
  21#include <linux/module.h>
  22#include <linux/mm.h>
  23#include <linux/crypto.h>
  24#include <asm/scatterlist.h>
  25#include <asm/byteorder.h>
  26
  27#define SHA1_DIGEST_SIZE        20
  28#define SHA1_HMAC_BLOCK_SIZE    64
  29
  30static inline u32 rol(u32 value, u32 bits)
  31{
  32        return (((value) << (bits)) | ((value) >> (32 - (bits))));
  33}
  34
  35/* blk0() and blk() perform the initial expand. */
  36/* I got the idea of expanding during the round function from SSLeay */
  37# define blk0(i) block32[i]
  38
  39#define blk(i) (block32[i&15] = rol(block32[(i+13)&15]^block32[(i+8)&15] \
  40    ^block32[(i+2)&15]^block32[i&15],1))
  41
  42/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */
  43#define R0(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk0(i)+0x5A827999+rol(v,5); \
  44                        w=rol(w,30);
  45#define R1(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5); \
  46                        w=rol(w,30);
  47#define R2(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);
  48#define R3(v,w,x,y,z,i) z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5); \
  49                        w=rol(w,30);
  50#define R4(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30);
  51
  52struct sha1_ctx {
  53        u64 count;
  54        u32 state[5];
  55        u8 buffer[64];
  56};
  57
  58/* Hash a single 512-bit block. This is the core of the algorithm. */
  59static void sha1_transform(u32 *state, const u8 *in)
  60{
  61        u32 a, b, c, d, e;
  62        u32 block32[16];
  63
  64        /* convert/copy data to workspace */
  65        for (a = 0; a < sizeof(block32)/sizeof(u32); a++)
  66          block32[a] = be32_to_cpu (((const u32 *)in)[a]);
  67
  68        /* Copy context->state[] to working vars */
  69        a = state[0];
  70        b = state[1];
  71        c = state[2];
  72        d = state[3];
  73        e = state[4];
  74
  75        /* 4 rounds of 20 operations each. Loop unrolled. */
  76        R0(a,b,c,d,e, 0); R0(e,a,b,c,d, 1); R0(d,e,a,b,c, 2); R0(c,d,e,a,b, 3);
  77        R0(b,c,d,e,a, 4); R0(a,b,c,d,e, 5); R0(e,a,b,c,d, 6); R0(d,e,a,b,c, 7);
  78        R0(c,d,e,a,b, 8); R0(b,c,d,e,a, 9); R0(a,b,c,d,e,10); R0(e,a,b,c,d,11);
  79        R0(d,e,a,b,c,12); R0(c,d,e,a,b,13); R0(b,c,d,e,a,14); R0(a,b,c,d,e,15);
  80        R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);
  81        R2(a,b,c,d,e,20); R2(e,a,b,c,d,21); R2(d,e,a,b,c,22); R2(c,d,e,a,b,23);
  82        R2(b,c,d,e,a,24); R2(a,b,c,d,e,25); R2(e,a,b,c,d,26); R2(d,e,a,b,c,27);
  83        R2(c,d,e,a,b,28); R2(b,c,d,e,a,29); R2(a,b,c,d,e,30); R2(e,a,b,c,d,31);
  84        R2(d,e,a,b,c,32); R2(c,d,e,a,b,33); R2(b,c,d,e,a,34); R2(a,b,c,d,e,35);
  85        R2(e,a,b,c,d,36); R2(d,e,a,b,c,37); R2(c,d,e,a,b,38); R2(b,c,d,e,a,39);
  86        R3(a,b,c,d,e,40); R3(e,a,b,c,d,41); R3(d,e,a,b,c,42); R3(c,d,e,a,b,43);
  87        R3(b,c,d,e,a,44); R3(a,b,c,d,e,45); R3(e,a,b,c,d,46); R3(d,e,a,b,c,47);
  88        R3(c,d,e,a,b,48); R3(b,c,d,e,a,49); R3(a,b,c,d,e,50); R3(e,a,b,c,d,51);
  89        R3(d,e,a,b,c,52); R3(c,d,e,a,b,53); R3(b,c,d,e,a,54); R3(a,b,c,d,e,55);
  90        R3(e,a,b,c,d,56); R3(d,e,a,b,c,57); R3(c,d,e,a,b,58); R3(b,c,d,e,a,59);
  91        R4(a,b,c,d,e,60); R4(e,a,b,c,d,61); R4(d,e,a,b,c,62); R4(c,d,e,a,b,63);
  92        R4(b,c,d,e,a,64); R4(a,b,c,d,e,65); R4(e,a,b,c,d,66); R4(d,e,a,b,c,67);
  93        R4(c,d,e,a,b,68); R4(b,c,d,e,a,69); R4(a,b,c,d,e,70); R4(e,a,b,c,d,71);
  94        R4(d,e,a,b,c,72); R4(c,d,e,a,b,73); R4(b,c,d,e,a,74); R4(a,b,c,d,e,75);
  95        R4(e,a,b,c,d,76); R4(d,e,a,b,c,77); R4(c,d,e,a,b,78); R4(b,c,d,e,a,79);
  96        /* Add the working vars back into context.state[] */
  97        state[0] += a;
  98        state[1] += b;
  99        state[2] += c;
 100        state[3] += d;
 101        state[4] += e;
 102        /* Wipe variables */
 103        a = b = c = d = e = 0;
 104        memset (block32, 0x00, sizeof block32);
 105}
 106
 107static void sha1_init(void *ctx)
 108{
 109        struct sha1_ctx *sctx = ctx;
 110        static const struct sha1_ctx initstate = {
 111          0,
 112          { 0x67452301, 0xEFCDAB89, 0x98BADCFE, 0x10325476, 0xC3D2E1F0 },
 113          { 0, }
 114        };
 115
 116        *sctx = initstate;
 117}
 118
 119static void sha1_update(void *ctx, const u8 *data, unsigned int len)
 120{
 121        struct sha1_ctx *sctx = ctx;
 122        unsigned int i, j;
 123
 124        j = (sctx->count >> 3) & 0x3f;
 125        sctx->count += len << 3;
 126
 127        if ((j + len) > 63) {
 128                memcpy(&sctx->buffer[j], data, (i = 64-j));
 129                sha1_transform(sctx->state, sctx->buffer);
 130                for ( ; i + 63 < len; i += 64) {
 131                        sha1_transform(sctx->state, &data[i]);
 132                }
 133                j = 0;
 134        }
 135        else i = 0;
 136        memcpy(&sctx->buffer[j], &data[i], len - i);
 137}
 138
 139
 140/* Add padding and return the message digest. */
 141static void sha1_final(void* ctx, u8 *out)
 142{
 143        struct sha1_ctx *sctx = ctx;
 144        u32 i, j, index, padlen;
 145        u64 t;
 146        u8 bits[8] = { 0, };
 147        static const u8 padding[64] = { 0x80, };
 148
 149        t = sctx->count;
 150        bits[7] = 0xff & t; t>>=8;
 151        bits[6] = 0xff & t; t>>=8;
 152        bits[5] = 0xff & t; t>>=8;
 153        bits[4] = 0xff & t; t>>=8;
 154        bits[3] = 0xff & t; t>>=8;
 155        bits[2] = 0xff & t; t>>=8;
 156        bits[1] = 0xff & t; t>>=8;
 157        bits[0] = 0xff & t;
 158
 159        /* Pad out to 56 mod 64 */
 160        index = (sctx->count >> 3) & 0x3f;
 161        padlen = (index < 56) ? (56 - index) : ((64+56) - index);
 162        sha1_update(sctx, padding, padlen);
 163
 164        /* Append length */
 165        sha1_update(sctx, bits, sizeof bits); 
 166
 167        /* Store state in digest */
 168        for (i = j = 0; i < 5; i++, j += 4) {
 169                u32 t2 = sctx->state[i];
 170                out[j+3] = t2 & 0xff; t2>>=8;
 171                out[j+2] = t2 & 0xff; t2>>=8;
 172                out[j+1] = t2 & 0xff; t2>>=8;
 173                out[j  ] = t2 & 0xff;
 174        }
 175
 176        /* Wipe context */
 177        memset(sctx, 0, sizeof *sctx);
 178}
 179
 180static struct crypto_alg alg = {
 181        .cra_name       =       "sha1",
 182        .cra_flags      =       CRYPTO_ALG_TYPE_DIGEST,
 183        .cra_blocksize  =       SHA1_HMAC_BLOCK_SIZE,
 184        .cra_ctxsize    =       sizeof(struct sha1_ctx),
 185        .cra_module     =       THIS_MODULE,
 186        .cra_list       =       LIST_HEAD_INIT(alg.cra_list),
 187        .cra_u          =       { .digest = {
 188        .dia_digestsize =       SHA1_DIGEST_SIZE,
 189        .dia_init       =       sha1_init,
 190        .dia_update     =       sha1_update,
 191        .dia_final      =       sha1_final } }
 192};
 193
 194static int __init init(void)
 195{
 196        return crypto_register_alg(&alg);
 197}
 198
 199static void __exit fini(void)
 200{
 201        crypto_unregister_alg(&alg);
 202}
 203
 204module_init(init);
 205module_exit(fini);
 206
 207MODULE_LICENSE("GPL");
 208MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");
 209