ext-cryptopp/iterhash.h
2002-10-04 17:31:41 +00:00

121 lines
3.4 KiB
C++

#ifndef CRYPTOPP_ITERHASH_H
#define CRYPTOPP_ITERHASH_H
#include "cryptlib.h"
#include "secblock.h"
#include "misc.h"
NAMESPACE_BEGIN(CryptoPP)
template <class T, class BASE>
class IteratedHashBase : public BASE
{
public:
typedef T HashWordType;
IteratedHashBase(unsigned int blockSize, unsigned int digestSize);
unsigned int DigestSize() const {return m_digest.size() * sizeof(T);};
unsigned int OptimalBlockSize() const {return BlockSize();}
void Update(const byte *input, unsigned int length);
byte * CreateUpdateSpace(unsigned int &size);
void Restart();
protected:
T GetBitCountHi() const {return (m_countLo >> (8*sizeof(T)-3)) + (m_countHi << 3);}
T GetBitCountLo() const {return m_countLo << 3;}
virtual unsigned int HashMultipleBlocks(const T *input, unsigned int length);
void PadLastBlock(unsigned int lastBlockSize, byte padFirst=0x80);
virtual void Init() =0;
virtual void HashBlock(const T *input) =0;
virtual unsigned int BlockSize() const =0;
SecBlock<T> m_data; // Data buffer
SecBlock<T> m_digest; // Message digest
private:
T m_countLo, m_countHi;
};
//! .
template <class T, class B, class BASE>
class IteratedHashBase2 : public IteratedHashBase<T, BASE>
{
public:
IteratedHashBase2(unsigned int blockSize, unsigned int digestSize)
: IteratedHashBase<T, BASE>(blockSize, digestSize) {}
typedef B ByteOrderClass;
typedef typename IteratedHashBase<T, BASE>::HashWordType HashWordType;
inline static void CorrectEndianess(HashWordType *out, const HashWordType *in, unsigned int byteCount)
{
ConditionalByteReverse(B::ToEnum(), out, in, byteCount);
}
void TruncatedFinal(byte *hash, unsigned int size);
protected:
void HashBlock(const HashWordType *input);
virtual void vTransform(const HashWordType *data) =0;
};
//! .
template <class T, class B, unsigned int S, class BASE = HashTransformation>
class IteratedHash : public IteratedHashBase2<T, B, BASE>
{
public:
enum {BLOCKSIZE = S};
private:
CRYPTOPP_COMPILE_ASSERT((BLOCKSIZE & (BLOCKSIZE - 1)) == 0); // blockSize is a power of 2
protected:
IteratedHash(unsigned int digestSize) : IteratedHashBase2<T, B, BASE>(BLOCKSIZE, digestSize) {}
unsigned int BlockSize() const {return BLOCKSIZE;}
};
template <class T, class B, unsigned int S, class M>
class IteratedHashWithStaticTransform : public IteratedHash<T, B, S>
{
protected:
IteratedHashWithStaticTransform(unsigned int digestSize) : IteratedHash<T, B, S>(digestSize) {}
void vTransform(const T *data) {M::Transform(m_digest, data);}
std::string AlgorithmName() const {return M::StaticAlgorithmName();}
};
// *************************************************************
template <class T, class B, class BASE> void IteratedHashBase2<T, B, BASE>::TruncatedFinal(byte *hash, unsigned int size)
{
ThrowIfInvalidTruncatedSize(size);
PadLastBlock(BlockSize() - 2*sizeof(HashWordType));
CorrectEndianess(m_data, m_data, BlockSize() - 2*sizeof(HashWordType));
m_data[m_data.size()-2] = B::ToEnum() ? GetBitCountHi() : GetBitCountLo();
m_data[m_data.size()-1] = B::ToEnum() ? GetBitCountLo() : GetBitCountHi();
vTransform(m_data);
CorrectEndianess(m_digest, m_digest, DigestSize());
memcpy(hash, m_digest, size);
Restart(); // reinit for next use
}
template <class T, class B, class BASE> void IteratedHashBase2<T, B, BASE>::HashBlock(const HashWordType *input)
{
if (NativeByteOrderIs(B::ToEnum()))
vTransform(input);
else
{
ByteReverse(m_data.begin(), input, BlockSize());
vTransform(m_data);
}
}
NAMESPACE_END
#endif