diff options
Diffstat (limited to 'lib/cryptopp/iterhash.cpp')
-rw-r--r-- | lib/cryptopp/iterhash.cpp | 160 |
1 files changed, 160 insertions, 0 deletions
diff --git a/lib/cryptopp/iterhash.cpp b/lib/cryptopp/iterhash.cpp new file mode 100644 index 000000000..1e31e9fb3 --- /dev/null +++ b/lib/cryptopp/iterhash.cpp @@ -0,0 +1,160 @@ +// iterhash.cpp - written and placed in the public domain by Wei Dai + +#ifndef __GNUC__ +#define CRYPTOPP_MANUALLY_INSTANTIATE_TEMPLATES +#endif + +#include "iterhash.h" +#include "misc.h" + +NAMESPACE_BEGIN(CryptoPP) + +template <class T, class BASE> void IteratedHashBase<T, BASE>::Update(const byte *input, size_t len) +{ + HashWordType oldCountLo = m_countLo, oldCountHi = m_countHi; + if ((m_countLo = oldCountLo + HashWordType(len)) < oldCountLo) + m_countHi++; // carry from low to high + m_countHi += (HashWordType)SafeRightShift<8*sizeof(HashWordType)>(len); + if (m_countHi < oldCountHi || SafeRightShift<2*8*sizeof(HashWordType)>(len) != 0) + throw HashInputTooLong(this->AlgorithmName()); + + unsigned int blockSize = this->BlockSize(); + unsigned int num = ModPowerOf2(oldCountLo, blockSize); + T* dataBuf = this->DataBuf(); + byte* data = (byte *)dataBuf; + + if (num != 0) // process left over data + { + if (num+len >= blockSize) + { + memcpy(data+num, input, blockSize-num); + HashBlock(dataBuf); + input += (blockSize-num); + len -= (blockSize-num); + num = 0; + // drop through and do the rest + } + else + { + memcpy(data+num, input, len); + return; + } + } + + // now process the input data in blocks of blockSize bytes and save the leftovers to m_data + if (len >= blockSize) + { + if (input == data) + { + assert(len == blockSize); + HashBlock(dataBuf); + return; + } + else if (IsAligned<T>(input)) + { + size_t leftOver = HashMultipleBlocks((T *)input, len); + input += (len - leftOver); + len = leftOver; + } + else + do + { // copy input first if it's not aligned correctly + memcpy(data, input, blockSize); + HashBlock(dataBuf); + input+=blockSize; + len-=blockSize; + } while (len >= blockSize); + } + + if (len && data != input) + memcpy(data, input, len); +} + +template <class T, class BASE> byte * IteratedHashBase<T, BASE>::CreateUpdateSpace(size_t &size) +{ + unsigned int blockSize = this->BlockSize(); + unsigned int num = ModPowerOf2(m_countLo, blockSize); + size = blockSize - num; + return (byte *)DataBuf() + num; +} + +template <class T, class BASE> size_t IteratedHashBase<T, BASE>::HashMultipleBlocks(const T *input, size_t length) +{ + unsigned int blockSize = this->BlockSize(); + bool noReverse = NativeByteOrderIs(this->GetByteOrder()); + T* dataBuf = this->DataBuf(); + do + { + if (noReverse) + this->HashEndianCorrectedBlock(input); + else + { + ByteReverse(dataBuf, input, this->BlockSize()); + this->HashEndianCorrectedBlock(dataBuf); + } + + input += blockSize/sizeof(T); + length -= blockSize; + } + while (length >= blockSize); + return length; +} + +template <class T, class BASE> void IteratedHashBase<T, BASE>::PadLastBlock(unsigned int lastBlockSize, byte padFirst) +{ + unsigned int blockSize = this->BlockSize(); + unsigned int num = ModPowerOf2(m_countLo, blockSize); + T* dataBuf = this->DataBuf(); + byte* data = (byte *)dataBuf; + data[num++] = padFirst; + if (num <= lastBlockSize) + memset(data+num, 0, lastBlockSize-num); + else + { + memset(data+num, 0, blockSize-num); + HashBlock(dataBuf); + memset(data, 0, lastBlockSize); + } +} + +template <class T, class BASE> void IteratedHashBase<T, BASE>::Restart() +{ + m_countLo = m_countHi = 0; + Init(); +} + +template <class T, class BASE> void IteratedHashBase<T, BASE>::TruncatedFinal(byte *digest, size_t size) +{ + this->ThrowIfInvalidTruncatedSize(size); + + T* dataBuf = this->DataBuf(); + T* stateBuf = this->StateBuf(); + unsigned int blockSize = this->BlockSize(); + ByteOrder order = this->GetByteOrder(); + + PadLastBlock(blockSize - 2*sizeof(HashWordType)); + dataBuf[blockSize/sizeof(T)-2+order] = ConditionalByteReverse(order, this->GetBitCountLo()); + dataBuf[blockSize/sizeof(T)-1-order] = ConditionalByteReverse(order, this->GetBitCountHi()); + + HashBlock(dataBuf); + + if (IsAligned<HashWordType>(digest) && size%sizeof(HashWordType)==0) + ConditionalByteReverse<HashWordType>(order, (HashWordType *)digest, stateBuf, size); + else + { + ConditionalByteReverse<HashWordType>(order, stateBuf, stateBuf, this->DigestSize()); + memcpy(digest, stateBuf, size); + } + + this->Restart(); // reinit for next use +} + +#ifdef __GNUC__ + template class IteratedHashBase<word64, HashTransformation>; + template class IteratedHashBase<word64, MessageAuthenticationCode>; + + template class IteratedHashBase<word32, HashTransformation>; + template class IteratedHashBase<word32, MessageAuthenticationCode>; +#endif + +NAMESPACE_END |