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/* hash.cpp
*
* Copyright (C) 2003 Sawtooth Consulting Ltd.
*
* This file is part of yaSSL.
*
* yaSSL 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.
*
* yaSSL 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
*/
/* hash.cpp implements a base for digest types
*/
#include "runtime.hpp"
#include <string.h>
#include <assert.h>
#include "hash.hpp"
namespace TaoCrypt {
HASHwithTransform::HASHwithTransform(word32 digSz, word32 buffSz)
{
assert(digSz <= MaxDigestSz);
assert(buffSz <= MaxBufferSz);
}
void HASHwithTransform::AddLength(word32 len)
{
HashLengthType tmp = loLen_;
if ( (loLen_ += len) < tmp)
hiLen_++; // carry low to high
hiLen_ += SafeRightShift<8*sizeof(HashLengthType)>(len);
}
// Update digest with data of size len, do in blocks
void HASHwithTransform::Update(const byte* data, word32 len)
{
// do block size increments
word32 blockSz = getBlockSize();
byte* local = reinterpret_cast<byte*>(buffer_);
while (len) {
word32 add = min(len, blockSz - buffLen_);
memcpy(&local[buffLen_], data, add);
buffLen_ += add;
data += add;
len -= add;
if (buffLen_ == blockSz) {
ByteReverseIf(local, local, blockSz, getByteOrder());
Transform();
AddLength(blockSz);
buffLen_ = 0;
}
}
}
// Final process, place digest in hash
void HASHwithTransform::Final(byte* hash)
{
word32 blockSz = getBlockSize();
word32 digestSz = getDigestSize();
word32 padSz = getPadSize();
ByteOrder order = getByteOrder();
AddLength(buffLen_); // before adding pads
HashLengthType preLoLen = GetBitCountLo();
HashLengthType preHiLen = GetBitCountHi();
byte* local = reinterpret_cast<byte*>(buffer_);
local[buffLen_++] = 0x80; // add 1
// pad with zeros
if (buffLen_ > padSz) {
memset(&local[buffLen_], 0, blockSz - buffLen_);
buffLen_ += blockSz - buffLen_;
ByteReverseIf(local, local, blockSz, order);
Transform();
buffLen_ = 0;
}
memset(&local[buffLen_], 0, padSz - buffLen_);
ByteReverseIf(local, local, blockSz, order);
memcpy(&local[padSz], order ? &preHiLen : &preLoLen, sizeof(preLoLen));
memcpy(&local[padSz+4], order ? &preLoLen : &preHiLen, sizeof(preLoLen));
Transform();
ByteReverseIf(digest_, digest_, digestSz, order);
memcpy(hash, digest_, digestSz);
Init(); // reset state
}
} // namespace
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