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
  30 static 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
  52 struct 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. */
  59 static 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
 107 static 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
 119 static 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. */
 141 static 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
 180 static 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
 194 static int __init init(void)
 195 {
 196         return crypto_register_alg(&alg);
 197 }
 198
 199 static void __exit fini(void)
 200 {
 201         crypto_unregister_alg(&alg);
 202 }
 203
 204 module_init(init);
 205 module_exit(fini);
 206
 207 MODULE_LICENSE("GPL");
 208 MODULE_DESCRIPTION("SHA1 Secure Hash Algorithm");