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Encryption and compression, native and managed

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29 Jun 2012CPOL7 min read 111.2K   6.9K   92  
DLL for native encryption and compression (using Crypto++). Includes RSA Key Generator in C#, and encryption and compression in ASP.NET (C#).
#ifndef CRYPTOPP_GZIP_H
#define CRYPTOPP_GZIP_H

#include "zdeflate.h"
#include "zinflate.h"
#include "crc.h"

NAMESPACE_BEGIN(CryptoPP)

/// GZIP Compression (RFC 1952)
class Gzip : public Deflator
{
public:
	Gzip(BufferedTransformation *attachment=NULL, unsigned int deflateLevel=DEFAULT_DEFLATE_LEVEL, unsigned int log2WindowSize=DEFAULT_LOG2_WINDOW_SIZE, bool detectUncompressible=true)
		: Deflator(attachment, deflateLevel, log2WindowSize, detectUncompressible) {}
	Gzip(const NameValuePairs &parameters, BufferedTransformation *attachment=NULL)
		: Deflator(parameters, attachment) {}

protected:
	enum {MAGIC1=0x1f, MAGIC2=0x8b,   // flags for the header
		  DEFLATED=8, FAST=4, SLOW=2};

	void WritePrestreamHeader();
	void ProcessUncompressedData(const byte *string, size_t length);
	void WritePoststreamTail();

	word32 m_totalLen;
	CRC32 m_crc;
};

/// GZIP Decompression (RFC 1952)
class Gunzip : public Inflator
{
public:
	typedef Inflator::Err Err;
	class HeaderErr : public Err {public: HeaderErr() : Err(INVALID_DATA_FORMAT, "Gunzip: header decoding error") {}};
	class TailErr : public Err {public: TailErr() : Err(INVALID_DATA_FORMAT, "Gunzip: tail too short") {}};
	class CrcErr : public Err {public: CrcErr() : Err(DATA_INTEGRITY_CHECK_FAILED, "Gunzip: CRC check error") {}};
	class LengthErr : public Err {public: LengthErr() : Err(DATA_INTEGRITY_CHECK_FAILED, "Gunzip: length check error") {}};

	/*! \param repeat decompress multiple compressed streams in series
		\param autoSignalPropagation 0 to turn off MessageEnd signal
	*/
	Gunzip(BufferedTransformation *attachment = NULL, bool repeat = false, int autoSignalPropagation = -1);

protected:
	enum {MAGIC1=0x1f, MAGIC2=0x8b,   // flags for the header
		DEFLATED=8};

	enum FLAG_MASKS {
		CONTINUED=2, EXTRA_FIELDS=4, FILENAME=8, COMMENTS=16, ENCRYPTED=32};

	unsigned int MaxPrestreamHeaderSize() const {return 1024;}
	void ProcessPrestreamHeader();
	void ProcessDecompressedData(const byte *string, size_t length);
	unsigned int MaxPoststreamTailSize() const {return 8;}
	void ProcessPoststreamTail();

	word32 m_length;
	CRC32 m_crc;
};

NAMESPACE_END

#endif

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License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)


Written By
Software Developer
Argentina Argentina
System developer from Argentina.

Programmed in VB 5,6,.NET, C#, Java, PL-SQL, Transac-SQL, C, C++ and even some "calculator" language.

Love to build small, useful applications.
Usually building big and complicated apps based on solid, reliable components.

Hobbies: reading, photography, chess, paddle, running.

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