crc.h
#ifndef CRYPTOPP_CRC32_H
#define CRYPTOPP_CRC32_H
#include "cryptlib.h"
NAMESPACE_BEGIN(CryptoPP)
const word32 CRC32_NEGL = 0xffffffffL;
#ifdef IS_LITTLE_ENDIAN
#define CRC32_INDEX(c) (c & 0xff)
#define CRC32_SHIFTED(c) (c >> 8)
#else
#define CRC32_INDEX(c) (c >> 24)
#define CRC32_SHIFTED(c) (c << 8)
#endif
//! CRC Checksum Calculation
class CRC32 : public HashTransformation
{
public:
CRYPTOPP_CONSTANT(DIGESTSIZE = 4)
CRC32();
void Update(const byte *input, size_t length);
void TruncatedFinal(byte *hash, size_t size);
unsigned int DigestSize() const {return DIGESTSIZE;}
static const char * StaticAlgorithmName() {return "CRC32";}
std::string AlgorithmName() const {return StaticAlgorithmName();}
void UpdateByte(byte b) {m_crc = m_tab[CRC32_INDEX(m_crc) ^ b] ^ CRC32_SHIFTED(m_crc);}
byte GetCrcByte(size_t i) const {return ((byte *)&(m_crc))[i];}
private:
void Reset() {m_crc = CRC32_NEGL;}
static const word32 m_tab[256];
word32 m_crc;
};
NAMESPACE_END
#endif
cryptlib.h
CRC32::DigestSize
unsigned int DigestSize() const
size of the hash/digest/MAC returned by Final()
Definition: crc.h:26
CRC32::TruncatedFinal
void TruncatedFinal(byte *hash, size_t size)
truncated version of Final()
CRC32::AlgorithmName
std::string AlgorithmName() const
returns name of this algorithm, not universally implemented yet
Definition: crc.h:28
CRC32::Update
void Update(const byte *input, size_t length)
process more input
HashTransformation
interface for hash functions and data processing part of MACs
Definition: cryptlib.h:530
CRC32
CRC Checksum Calculation.
Definition: crc.h:19