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SHA1Engine.cpp

//
// SHA1Engine.cpp
//
// $Id: //poco/1.2/Foundation/src/SHA1Engine.cpp#2 $
//
// Library: Foundation
// Package: Crypt
// Module:  SHA1Engine
//
// Based on the public domain implementation by Peter C. Gutmann
// on 2 Sep 1992, modified by Carl Ellison to be SHA-1.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
// 
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//


#include "Poco/SHA1Engine.h"
#include <string.h>


#ifdef POCO_ARCH_LITTLE_ENDIAN
      #define SHA1_BYTE_REVERSE(x, y) byteReverse(x, y)
#else
      #define SHA1_BYTE_REVERSE(x, y)
#endif


namespace Poco {


SHA1Engine::SHA1Engine()
{
      _digest.reserve(16);
      reset();
}


SHA1Engine::~SHA1Engine()
{
      reset();
}


inline void SHA1Engine::byteReverse(UInt32* buffer, int byteCount)
{
#ifdef POCO_ARCH_LITTLE_ENDIAN
      byteCount /= sizeof(UInt32);
      for(int count = 0; count < byteCount; count++)
      {
            UInt32 value = (buffer[ count ] << 16) | (buffer[ count ] >> 16);
            buffer[count] = ((value & 0xFF00FF00L) >> 8) | ((value & 0x00FF00FFL) << 8);
      }
#endif // POCO_ARCH_LITTLE_ENDIAN
}

      
00080 void SHA1Engine::updateImpl(const void* buffer_, unsigned count)
{
      const BYTE* buffer = (const BYTE*) buffer_;
      BYTE* db = (BYTE*) &_context.data[0];

      /* Update bitcount */
      if ((_context.countLo + ((UInt32) count << 3)) < _context.countLo)
            _context.countHi++; /* Carry from low to high bitCount */
      _context.countLo += ((UInt32) count << 3);
      _context.countHi += ((UInt32 ) count >> 29);

      /* Process data in BLOCK_SIZE chunks */
      while (count-- > 0)
      {
            db[_context.slop++] = *(buffer++);
            if (_context.slop == BLOCK_SIZE)
            { 
                  /* transform this one block */
                  SHA1_BYTE_REVERSE(_context.data, BLOCK_SIZE);
                  transform();
                  _context.slop = 0 ;     /* no slop left */
            }
      }
}


00106 unsigned SHA1Engine::digestLength() const
{
      return DIGEST_SIZE;
}


00112 void SHA1Engine::reset()
{
      _context.digest[0] = 0x67452301L;
      _context.digest[1] = 0xEFCDAB89L;
      _context.digest[2] = 0x98BADCFEL;
      _context.digest[3] = 0x10325476L;
      _context.digest[4] = 0xC3D2E1F0L;
      _context.countLo   = 0;
      _context.countHi   = 0;
      _context.slop      = 0;
      memset(_context.data, 0, sizeof(_context.data));
}


00126 const DigestEngine::Digest& SHA1Engine::digest()
{
      int count;
      UInt32 lowBitcount  = _context.countLo;
      UInt32 highBitcount = _context.countHi;

      /* Compute number of bytes mod 64 */
      count = (int) ((_context.countLo >> 3) & 0x3F);

      /* Set the first char of padding to 0x80.  This is safe since there is
            always at least one byte free */
      ((BYTE*) _context.data)[count++] = 0x80;

      /* Pad out to 56 mod 64 */
      if (count > 56)
      {
            /* Two lots of padding:  Pad the first block to 64 bytes */
            memset((BYTE*) &_context.data + count, 0, 64 - count);
            SHA1_BYTE_REVERSE(_context.data, BLOCK_SIZE);
            transform();

            /* Now fill the next block with 56 bytes */
            memset(&_context.data, 0, 56);
      }
      else
      {
            /* Pad block to 56 bytes */
            memset((BYTE*) &_context.data + count, 0, 56 - count);
      }
      SHA1_BYTE_REVERSE(_context.data, BLOCK_SIZE);

      /* Append length in bits and transform */
      _context.data[14] = highBitcount;
      _context.data[15] = lowBitcount;

      transform();
      SHA1_BYTE_REVERSE(_context.data, DIGEST_SIZE);

      unsigned char hash[DIGEST_SIZE];
      for (count = 0; count < DIGEST_SIZE; count++)
            hash[count] = (BYTE) ((_context.digest[count>>2]) >> (8*(3-(count & 0x3)))) & 0xff;
      _digest.clear();
      _digest.insert(_digest.begin(), hash, hash + DIGEST_SIZE);
      reset();
      return _digest;
}


/* The SHA f()-functions */
#define f1(x,y,z)   ( ( x & y ) | ( ~x & z ) )              /* Rounds  0-19 */
#define f2(x,y,z)   ( x ^ y ^ z )                           /* Rounds 20-39 */
#define f3(x,y,z)   ( ( x & y ) | ( x & z ) | ( y & z ) )   /* Rounds 40-59 */
#define f4(x,y,z)   ( x ^ y ^ z )                           /* Rounds 60-79 */


/* The SHA Mysterious Constants */
#define K1  0x5A827999L     /* Rounds  0-19 */
#define K2  0x6ED9EBA1L     /* Rounds 20-39 */
#define K3  0x8F1BBCDCL     /* Rounds 40-59 */
#define K4  0xCA62C1D6L     /* Rounds 60-79 */


/* 32-bit rotate - kludged with shifts */
typedef UInt32 UL;      /* to save space */


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


/* The initial expanding function */
#define expand(count)   W[ count ] = S(1,(W[ count - 3 ] ^ W[ count - 8 ] ^ W[ count - 14 ] ^ W[ count - 16 ]))   /* to make this SHA-1 */


/* The four SHA sub-rounds */
#define subRound1(count)    \
{ \
    temp = S( 5, A ) + f1( B, C, D ) + E + W[ count ] + K1; \
    E = D; \
    D = C; \
    C = S( 30, B ); \
    B = A; \
    A = temp; \
}

#define subRound2(count)    \
{ \
    temp = S( 5, A ) + f2( B, C, D ) + E + W[ count ] + K2; \
    E = D; \
    D = C; \
    C = S( 30, B ); \
    B = A; \
    A = temp; \
}

#define subRound3(count)    \
{ \
    temp = S( 5, A ) + f3( B, C, D ) + E + W[ count ] + K3; \
    E = D; \
    D = C; \
    C = S( 30, B ); \
    B = A; \
    A = temp; \
}

#define subRound4(count)    \
{ \
    temp = S( 5, A ) + f4( B, C, D ) + E + W[ count ] + K4; \
    E = D; \
    D = C; \
    C = S( 30, B ); \
    B = A; \
    A = temp; \
}


void SHA1Engine::transform()
{
      UInt32 W[80];
      UInt32 temp;
      UInt32 A, B, C, D, E;
      int i;

      /* Step A.  Copy the data buffer into the local work buffer */
      for( i = 0; i < 16; i++ )
      W[ i ] = _context.data[ i ];

      /* Step B.  Expand the 16 words into 64 temporary data words */
      expand( 16 ); expand( 17 ); expand( 18 ); expand( 19 ); expand( 20 );
      expand( 21 ); expand( 22 ); expand( 23 ); expand( 24 ); expand( 25 );
      expand( 26 ); expand( 27 ); expand( 28 ); expand( 29 ); expand( 30 );
      expand( 31 ); expand( 32 ); expand( 33 ); expand( 34 ); expand( 35 );
      expand( 36 ); expand( 37 ); expand( 38 ); expand( 39 ); expand( 40 );
      expand( 41 ); expand( 42 ); expand( 43 ); expand( 44 ); expand( 45 );
      expand( 46 ); expand( 47 ); expand( 48 ); expand( 49 ); expand( 50 );
      expand( 51 ); expand( 52 ); expand( 53 ); expand( 54 ); expand( 55 );
      expand( 56 ); expand( 57 ); expand( 58 ); expand( 59 ); expand( 60 );
      expand( 61 ); expand( 62 ); expand( 63 ); expand( 64 ); expand( 65 );
      expand( 66 ); expand( 67 ); expand( 68 ); expand( 69 ); expand( 70 );
      expand( 71 ); expand( 72 ); expand( 73 ); expand( 74 ); expand( 75 );
      expand( 76 ); expand( 77 ); expand( 78 ); expand( 79 );

      /* Step C.  Set up first buffer */
      A = _context.digest[ 0 ];
      B = _context.digest[ 1 ];
      C = _context.digest[ 2 ];
      D = _context.digest[ 3 ];
      E = _context.digest[ 4 ];

      /* Step D.  Serious mangling, divided into four sub-rounds */
      subRound1( 0 ); subRound1( 1 ); subRound1( 2 ); subRound1( 3 );
      subRound1( 4 ); subRound1( 5 ); subRound1( 6 ); subRound1( 7 );
      subRound1( 8 ); subRound1( 9 ); subRound1( 10 ); subRound1( 11 );
      subRound1( 12 ); subRound1( 13 ); subRound1( 14 ); subRound1( 15 );
      subRound1( 16 ); subRound1( 17 ); subRound1( 18 ); subRound1( 19 );
      subRound2( 20 ); subRound2( 21 ); subRound2( 22 ); subRound2( 23 );
      subRound2( 24 ); subRound2( 25 ); subRound2( 26 ); subRound2( 27 );
      subRound2( 28 ); subRound2( 29 ); subRound2( 30 ); subRound2( 31 );
      subRound2( 32 ); subRound2( 33 ); subRound2( 34 ); subRound2( 35 );
      subRound2( 36 ); subRound2( 37 ); subRound2( 38 ); subRound2( 39 );
      subRound3( 40 ); subRound3( 41 ); subRound3( 42 ); subRound3( 43 );
      subRound3( 44 ); subRound3( 45 ); subRound3( 46 ); subRound3( 47 );
      subRound3( 48 ); subRound3( 49 ); subRound3( 50 ); subRound3( 51 );
      subRound3( 52 ); subRound3( 53 ); subRound3( 54 ); subRound3( 55 );
      subRound3( 56 ); subRound3( 57 ); subRound3( 58 ); subRound3( 59 );
      subRound4( 60 ); subRound4( 61 ); subRound4( 62 ); subRound4( 63 );
      subRound4( 64 ); subRound4( 65 ); subRound4( 66 ); subRound4( 67 );
      subRound4( 68 ); subRound4( 69 ); subRound4( 70 ); subRound4( 71 );
      subRound4( 72 ); subRound4( 73 ); subRound4( 74 ); subRound4( 75 );
      subRound4( 76 ); subRound4( 77 ); subRound4( 78 ); subRound4( 79 );

      /* Step E.  Build message digest */
      _context.digest[ 0 ] += A;
      _context.digest[ 1 ] += B;
      _context.digest[ 2 ] += C;
      _context.digest[ 3 ] += D;
      _context.digest[ 4 ] += E;
}


} // namespace Poco

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