sha1.c

   1 /*
   2  * The contents of this file are subject to the Mozilla Public
   3  * License Version 1.1 (the "License"); you may not use this file
   4  * except in compliance with the License. You may obtain a copy of
   5  * the License at http://www.mozilla.org/MPL/
   6  *
   7  * Software distributed under the License is distributed on an "AS
   8  * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
   9  * implied. See the License for the specific language governing
  10  * rights and limitations under the License.
  11  *
  12  * The Original Code is SHA 180-1 Reference Implementation (Compact version)
  13  *
  14  * The Initial Developer of the Original Code is Paul Kocher of
  15  * Cryptography Research.  Portions created by Paul Kocher are
  16  * Copyright (C) 1995-9 by Cryptography Research, Inc.  All
  17  * Rights Reserved.
  18  *
  19  * Contributor(s):
  20  *
  21  *     Paul Kocher
  22  *
  23  * Alternatively, the contents of this file may be used under the
  24  * terms of the GNU General Public License Version 2 or later (the
  25  * "GPL"), in which case the provisions of the GPL are applicable
  26  * instead of those above.  If you wish to allow use of your
  27  * version of this file only under the terms of the GPL and not to
  28  * allow others to use your version of this file under the MPL,
  29  * indicate your decision by deleting the provisions above and
  30  * replace them with the notice and other provisions required by
  31  * the GPL.  If you do not delete the provisions above, a recipient
  32  * may use your version of this file under either the MPL or the
  33  * GPL.
  34  */
  35
  36 #include "sha1.h"
  37
  38 static void shaHashBlock(SHA_CTX *ctx);
  39
  40 void SHA1_Init(SHA_CTX *ctx) {
  41   int i;
  42
  43   ctx->lenW = 0;
  44   ctx->sizeHi = ctx->sizeLo = 0;
  45
  46   /* Initialize H with the magic constants (see FIPS180 for constants)
  47    */
  48   ctx->H[0] = 0x67452301;
  49   ctx->H[1] = 0xefcdab89;
  50   ctx->H[2] = 0x98badcfe;
  51   ctx->H[3] = 0x10325476;
  52   ctx->H[4] = 0xc3d2e1f0;
  53
  54   for (i = 0; i < 80; i++)
  55     ctx->W[i] = 0;
  56 }
  57
  58
  59 void SHA1_Update(SHA_CTX *ctx, void *_dataIn, int len) {
  60   unsigned char *dataIn = _dataIn;
  61   int i;
  62
  63   /* Read the data into W and process blocks as they get full
  64    */
  65   for (i = 0; i < len; i++) {
  66     ctx->W[ctx->lenW / 4] <<= 8;
  67     ctx->W[ctx->lenW / 4] |= (unsigned int)dataIn[i];
  68     if ((++ctx->lenW) % 64 == 0) {
  69       shaHashBlock(ctx);
  70       ctx->lenW = 0;
  71     }
  72     ctx->sizeLo += 8;
  73     ctx->sizeHi += (ctx->sizeLo < 8);
  74   }
  75 }
  76
  77
  78 void SHA1_Final(unsigned char hashout[20], SHA_CTX *ctx) {
  79   unsigned char pad0x80 = 0x80;
  80   unsigned char pad0x00 = 0x00;
  81   unsigned char padlen[8];
  82   int i;
  83
  84   /* Pad with a binary 1 (e.g. 0x80), then zeroes, then length
  85    */
  86   padlen[0] = (unsigned char)((ctx->sizeHi >> 24) & 255);
  87   padlen[1] = (unsigned char)((ctx->sizeHi >> 16) & 255);
  88   padlen[2] = (unsigned char)((ctx->sizeHi >> 8) & 255);
  89   padlen[3] = (unsigned char)((ctx->sizeHi >> 0) & 255);
  90   padlen[4] = (unsigned char)((ctx->sizeLo >> 24) & 255);
  91   padlen[5] = (unsigned char)((ctx->sizeLo >> 16) & 255);
  92   padlen[6] = (unsigned char)((ctx->sizeLo >> 8) & 255);
  93   padlen[7] = (unsigned char)((ctx->sizeLo >> 0) & 255);
  94   SHA1_Update(ctx, &pad0x80, 1);
  95   while (ctx->lenW != 56)
  96     SHA1_Update(ctx, &pad0x00, 1);
  97   SHA1_Update(ctx, padlen, 8);
  98
  99   /* Output hash
 100    */
 101   for (i = 0; i < 20; i++) {
 102     hashout[i] = (unsigned char)(ctx->H[i / 4] >> 24);
 103     ctx->H[i / 4] <<= 8;
 104   }
 105
 106   /*
 107    *  Re-initialize the context (also zeroizes contents)
 108    */
 109   SHA1_Init(ctx);
 110 }
 111
 112
 113 #define SHA_ROT(X,n) (((X) << (n)) | ((X) >> (32-(n))))
 114
 115 static void shaHashBlock(SHA_CTX *ctx) {
 116   int t;
 117   unsigned int A,B,C,D,E,TEMP;
 118
 119   for (t = 16; t <= 79; t++)
 120     ctx->W[t] =
 121       SHA_ROT(ctx->W[t-3] ^ ctx->W[t-8] ^ ctx->W[t-14] ^ ctx->W[t-16], 1);
 122
 123   A = ctx->H[0];
 124   B = ctx->H[1];
 125   C = ctx->H[2];
 126   D = ctx->H[3];
 127   E = ctx->H[4];
 128
 129   for (t = 0; t <= 19; t++) {
 130     TEMP = SHA_ROT(A,5) + (((C^D)&B)^D)     + E + ctx->W[t] + 0x5a827999;
 131     E = D; D = C; C = SHA_ROT(B, 30); B = A; A = TEMP;
 132   }
 133   for (t = 20; t <= 39; t++) {
 134     TEMP = SHA_ROT(A,5) + (B^C^D)           + E + ctx->W[t] + 0x6ed9eba1;
 135     E = D; D = C; C = SHA_ROT(B, 30); B = A; A = TEMP;
 136   }
 137   for (t = 40; t <= 59; t++) {
 138     TEMP = SHA_ROT(A,5) + ((B&C)|(D&(B|C))) + E + ctx->W[t] + 0x8f1bbcdc;
 139     E = D; D = C; C = SHA_ROT(B, 30); B = A; A = TEMP;
 140   }
 141   for (t = 60; t <= 79; t++) {
 142     TEMP = SHA_ROT(A,5) + (B^C^D)           + E + ctx->W[t] + 0xca62c1d6;
 143     E = D; D = C; C = SHA_ROT(B, 30); B = A; A = TEMP;
 144   }
 145
 146   ctx->H[0] += A;
 147   ctx->H[1] += B;
 148   ctx->H[2] += C;
 149   ctx->H[3] += D;
 150   ctx->H[4] += E;
 151 }
 152