/cyassl-1.2.0/ctaocrypt/src/sha.c

/* sha.c

 *

 * Copyright (C) 2006-2009 Sawtooth Consulting Ltd.

 *

 * This file is part of CyaSSL.

 *

 * CyaSSL is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License as published by

 * the Free Software Foundation; either version 2 of the License, or

 * (at your option) any later version.

 *

 * CyaSSL is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA

 */





#include "sha.h"

#ifdef NO_INLINE

    #include "misc.h"

#else

    #include "misc.c"

#endif

#include <string.h>

#include <assert.h>





#ifndef min



    static INLINE word32 min(word32 a, word32 b)

    {

        return a > b ? b : a;

    }



#endif /* min */





void InitSha(Sha* sha)

{

    sha->digest[0] = 0x67452301L;

    sha->digest[1] = 0xEFCDAB89L;

    sha->digest[2] = 0x98BADCFEL;

    sha->digest[3] = 0x10325476L;

    sha->digest[4] = 0xC3D2E1F0L;



    sha->buffLen = 0;

    sha->loLen   = 0;

    sha->hiLen   = 0;

}





#define f1(x,y,z) (z^(x &(y^z)))

#define f2(x,y,z) (x^y^z)

#define f3(x,y,z) ((x&y)|(z&(x|y)))

#define f4(x,y,z) (x^y^z)



/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */

#define R0(v,w,x,y,z,i) z+= f1(w,x,y) + W[i] + 0x5A827999+ rotlFixed(v,5); w = rotlFixed(w,30);

#define R1(v,w,x,y,z,i) z+= f1(w,x,y) + W[i] + 0x5A827999+ rotlFixed(v,5); w = rotlFixed(w,30);

#define R2(v,w,x,y,z,i) z+= f2(w,x,y) + W[i] + 0x6ED9EBA1+ rotlFixed(v,5); w = rotlFixed(w,30);

#define R3(v,w,x,y,z,i) z+= f3(w,x,y) + W[i] + 0x8F1BBCDC+ rotlFixed(v,5); w = rotlFixed(w,30);

#define R4(v,w,x,y,z,i) z+= f4(w,x,y) + W[i] + 0xCA62C1D6+ rotlFixed(v,5); w = rotlFixed(w,30);





static void Transform(Sha* sha)

{

    word32 W[80], i;



    /* Copy context->state[] to working vars */ 

    word32 a = sha->digest[0];

    word32 b = sha->digest[1];

    word32 c = sha->digest[2];

    word32 d = sha->digest[3];

    word32 e = sha->digest[4];



    for (i = 0; i < 16; i++)

        W[i] = sha->buffer[i];



    for (i = 16; i < 80; i++)

        W[i] = rotlFixed(W[i-3]^W[i-8]^W[i-14]^W[i-16],1);

    

    /* 4 rounds of 20 operations each.  */

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

        R0(a,b,c,d,e,i); i++;

        R0(e,a,b,c,d,i); i++;

        R0(d,e,a,b,c,i); i++;

        R0(c,d,e,a,b,i); i++;

        R0(b,c,d,e,a,i); i++;

    }



    for (i = 20; i < 40; ) {

        R2(a,b,c,d,e,i); i++;

        R2(e,a,b,c,d,i); i++;

        R2(d,e,a,b,c,i); i++;

        R2(c,d,e,a,b,i); i++;

        R2(b,c,d,e,a,i); i++;

    }



    for (i = 40; i < 60; ) {

        R3(a,b,c,d,e,i); i++;

        R3(e,a,b,c,d,i); i++;

        R3(d,e,a,b,c,i); i++;

        R3(c,d,e,a,b,i); i++;

        R3(b,c,d,e,a,i); i++;

    }



    for (i = 60; i < 80; ) {

        R4(a,b,c,d,e,i); i++;

        R4(e,a,b,c,d,i); i++;

        R4(d,e,a,b,c,i); i++;

        R4(c,d,e,a,b,i); i++;

        R4(b,c,d,e,a,i); i++;

    }



    /* Add the working vars back into digest state[] */

    sha->digest[0] += a;

    sha->digest[1] += b;

    sha->digest[2] += c;

    sha->digest[3] += d;

    sha->digest[4] += e;

}





static INLINE void AddLength(Sha* sha, word32 len)

{

    word32 tmp = sha->loLen;

    if ( (sha->loLen += len) < tmp)

        sha->hiLen++;                       /* carry low to high */

}





void ShaUpdate(Sha* sha, const byte* data, word32 len)

{

    /* do block size increments */

    byte* local = (byte*)sha->buffer;



    while (len) {

        word32 add = min(len, SHA_BLOCK_SIZE - sha->buffLen);

        memcpy(&local[sha->buffLen], data, add);



        sha->buffLen += add;

        data         += add;

        len          -= add;



        if (sha->buffLen == SHA_BLOCK_SIZE) {

            #ifdef LITTLE_ENDIAN_ORDER

                ByteReverseBytes(local, local, SHA_BLOCK_SIZE);

            #endif

            Transform(sha);

            AddLength(sha, SHA_BLOCK_SIZE);

            sha->buffLen = 0;

        }

    }

}





void ShaFinal(Sha* sha, byte* hash)

{

    byte* local = (byte*)sha->buffer;



    AddLength(sha, sha->buffLen);               /* before adding pads */



    local[sha->buffLen++] = 0x80;  /* add 1 */



    /* pad with zeros */

    if (sha->buffLen > SHA_PAD_SIZE) {

        memset(&local[sha->buffLen], 0, SHA_BLOCK_SIZE - sha->buffLen);

        sha->buffLen += SHA_BLOCK_SIZE - sha->buffLen;



        #ifdef LITTLE_ENDIAN_ORDER

            ByteReverseBytes(local, local, SHA_BLOCK_SIZE);

        #endif

        Transform(sha);

        sha->buffLen = 0;

    }

    memset(&local[sha->buffLen], 0, SHA_PAD_SIZE - sha->buffLen);

   

    /* put lengths in bits */

    sha->loLen = sha->loLen << 3;

    sha->hiLen = (sha->loLen >> (8*sizeof(sha->loLen) - 3)) + 

                 (sha->hiLen << 3);



    /* store lengths */

    #ifdef LITTLE_ENDIAN_ORDER

        ByteReverseBytes(local, local, SHA_BLOCK_SIZE);

    #endif

    memcpy(&local[SHA_PAD_SIZE], &sha->hiLen, sizeof(word32));

    memcpy(&local[SHA_PAD_SIZE + sizeof(word32)], &sha->loLen, sizeof(word32));



    Transform(sha);

    #ifdef LITTLE_ENDIAN_ORDER

        ByteReverseWords(sha->digest, sha->digest, SHA_DIGEST_SIZE);

    #endif

    memcpy(hash, sha->digest, SHA_DIGEST_SIZE);



    InitSha(sha);  /* reset state */

}