/*

  * The contents of this file are subject to the Mozilla Public

  * License Version 1.1 (the "License"); you may not use this file

  * except in compliance with the License. You may obtain a copy of

  * the License at http://www.mozilla.org/MPL/

  *

  * Software distributed under the License is distributed on an "AS

  * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or

  * implied. See the License for the specific language governing

  * rights and limitations under the License.

  *

  * The Original Code is SHA 180-1 Reference Implementation (Compact version)

  *

  * The Initial Developer of the Original Code is Paul Kocher of

  * Cryptography Research.  Portions created by Paul Kocher are

  * Copyright (C) 1995-9 by Cryptography Research, Inc.  All

  * Rights Reserved.

  *

  * Contributor(s):

  *

  *     Paul Kocher

  *

  * Alternatively, the contents of this file may be used under the

  * terms of the GNU General Public License Version 2 or later (the

  * "GPL"), in which case the provisions of the GPL are applicable

  * instead of those above.  If you wish to allow use of your

  * version of this file only under the terms of the GPL and not to

  * allow others to use your version of this file under the MPL,

  * indicate your decision by deleting the provisions above and

  * replace them with the notice and other provisions required by

  * the GPL.  If you do not delete the provisions above, a recipient

  * may use your version of this file under either the MPL or the

  * GPL.

  */

 #include "sha1.h"

 static void shaHashBlock(SHA_CTX *ctx);

 void SHA1_Init(SHA_CTX *ctx) {

   int i;

   ctx->lenW = 0;

   ctx->sizeHi = ctx->sizeLo = 0;

   /* Initialize H with the magic constants (see FIPS180 for constants)

    */

   ctx->H[0] = 0x67452301;

   ctx->H[1] = 0xefcdab89;

   ctx->H[2] = 0x98badcfe;

   ctx->H[3] = 0x10325476;

   ctx->H[4] = 0xc3d2e1f0;

   for (i = 0; i < 80; i++)

     ctx->W[i] = 0;

 }

 void SHA1_Update(SHA_CTX *ctx, const void *_dataIn, int len) {

   const unsigned char *dataIn = _dataIn;

   int i;

   /* Read the data into W and process blocks as they get full

    */

   for (i = 0; i < len; i++) {

     ctx->W[ctx->lenW / 4] <<= 8;

     ctx->W[ctx->lenW / 4] |= (unsigned int)dataIn[i];

     if ((++ctx->lenW) % 64 == 0) {

       shaHashBlock(ctx);

       ctx->lenW = 0;

     }

     ctx->sizeLo += 8;

     ctx->sizeHi += (ctx->sizeLo < 8);

   }

 }

 void SHA1_Final(unsigned char hashout[20], SHA_CTX *ctx) {

   unsigned char pad0x80 = 0x80;

   unsigned char pad0x00 = 0x00;

   unsigned char padlen[8];

   int i;

   /* Pad with a binary 1 (e.g. 0x80), then zeroes, then length

    */

   padlen[0] = (unsigned char)((ctx->sizeHi >> 24) & 255);

   padlen[1] = (unsigned char)((ctx->sizeHi >> 16) & 255);

   padlen[2] = (unsigned char)((ctx->sizeHi >> 8) & 255);

   padlen[3] = (unsigned char)((ctx->sizeHi >> 0) & 255);

   padlen[4] = (unsigned char)((ctx->sizeLo >> 24) & 255);

   padlen[5] = (unsigned char)((ctx->sizeLo >> 16) & 255);

   padlen[6] = (unsigned char)((ctx->sizeLo >> 8) & 255);

   padlen[7] = (unsigned char)((ctx->sizeLo >> 0) & 255);

   SHA1_Update(ctx, &pad0x80, 1);

   while (ctx->lenW != 56)

     SHA1_Update(ctx, &pad0x00, 1);

   SHA1_Update(ctx, padlen, 8);

   /* Output hash

    */

   for (i = 0; i < 20; i++) {

     hashout[i] = (unsigned char)(ctx->H[i / 4] >> 24);

     ctx->H[i / 4] <<= 8;

   }

   /*

    *  Re-initialize the context (also zeroizes contents)

    */

   SHA1_Init(ctx);

 }

 #define SHA_ROT(X,n) (((X) << (n)) | ((X) >> (32-(n))))

 static void shaHashBlock(SHA_CTX *ctx) {

   int t;

   unsigned int A,B,C,D,E,TEMP;

   for (t = 16; t <= 79; t++)

     ctx->W[t] =

       SHA_ROT(ctx->W[t-3] ^ ctx->W[t-8] ^ ctx->W[t-14] ^ ctx->W[t-16], 1);

   A = ctx->H[0];

   B = ctx->H[1];

   C = ctx->H[2];

   D = ctx->H[3];

   E = ctx->H[4];

   for (t = 0; t <= 19; t++) {

     TEMP = SHA_ROT(A,5) + (((C^D)&B)^D)     + E + ctx->W[t] + 0x5a827999;

     E = D; D = C; C = SHA_ROT(B, 30); B = A; A = TEMP;

   }

   for (t = 20; t <= 39; t++) {

     TEMP = SHA_ROT(A,5) + (B^C^D)           + E + ctx->W[t] + 0x6ed9eba1;

     E = D; D = C; C = SHA_ROT(B, 30); B = A; A = TEMP;

   }

   for (t = 40; t <= 59; t++) {

     TEMP = SHA_ROT(A,5) + ((B&C)|(D&(B|C))) + E + ctx->W[t] + 0x8f1bbcdc;

     E = D; D = C; C = SHA_ROT(B, 30); B = A; A = TEMP;

   }

   for (t = 60; t <= 79; t++) {

     TEMP = SHA_ROT(A,5) + (B^C^D)           + E + ctx->W[t] + 0xca62c1d6;

     E = D; D = C; C = SHA_ROT(B, 30); B = A; A = TEMP;

   }

   ctx->H[0] += A;

   ctx->H[1] += B;

   ctx->H[2] += C;

   ctx->H[3] += D;

   ctx->H[4] += E;

 }