Add CRC-32C using CXX and SSE4 (Issue 160)

1 files changed, 29 insertions, 3 deletions

diff --git a/crc.h b/crc.h
index d31555dd..89b68629 100644
--- a/crc.h
+++ b/crc.h
@@ -2,7 +2,7 @@
 

 //! \file

 //! \headerfile crc.h

-//! \brief Classes for CRC-32 checksum algorithm

+//! \brief Classes for CRC-32 and CRC-32C checksum algorithm

 

 #ifndef CRYPTOPP_CRC32_H

 #define CRYPTOPP_CRC32_H

@@ -21,7 +21,8 @@ const word32 CRC32_NEGL = 0xffffffffL;
 #define CRC32_SHIFTED(c) (c << 8)

 #endif

 

-//! CRC Checksum Calculation

+//! \brief CRC-32 Checksum Calculation

+//! \details Uses CRC polynomial 0xEDB88320

 class CRC32 : public HashTransformation

 {

 public:

@@ -36,9 +37,34 @@ public:
 	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];}

 

+protected:

+	void Reset() {m_crc = CRC32_NEGL;}

+

 private:

+	static const word32 m_tab[256];

+	word32 m_crc;

+};

+

+//! \brief CRC-32C Checksum Calculation

+//! \details Uses CRC polynomial 0x82F63B78

+class CRC32C : public HashTransformation

+{

+public:

+	CRYPTOPP_CONSTANT(DIGESTSIZE = 4)

+	CRC32C();

+	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 "CRC32C";}

+    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];}

+

+protected:

 	void Reset() {m_crc = CRC32_NEGL;}

-	

+

+private:

 	static const word32 m_tab[256];

 	word32 m_crc;

 };