1#ifndef CRYPTOPP_GZIP_H
2#define CRYPTOPP_GZIP_H
3
4#include "zdeflate.h"
5#include "zinflate.h"
6#include "crc.h"
7
8NAMESPACE_BEGIN(CryptoPP)
9
10/// GZIP Compression (RFC 1952)
11class Gzip : public Deflator
12{
13public:
14	Gzip(BufferedTransformation *attachment=NULL, unsigned int deflateLevel=DEFAULT_DEFLATE_LEVEL, unsigned int log2WindowSize=DEFAULT_LOG2_WINDOW_SIZE, bool detectUncompressible=true)
15		: Deflator(attachment, deflateLevel, log2WindowSize, detectUncompressible) {}
16	Gzip(const NameValuePairs &parameters, BufferedTransformation *attachment=NULL)
17		: Deflator(parameters, attachment) {}
18
19protected:
20	enum {MAGIC1=0x1f, MAGIC2=0x8b,   // flags for the header
21		  DEFLATED=8, FAST=4, SLOW=2};
22
23	void WritePrestreamHeader();
24	void ProcessUncompressedData(const byte *string, size_t length);
25	void WritePoststreamTail();
26
27	word32 m_totalLen;
28	CRC32 m_crc;
29};
30
31/// GZIP Decompression (RFC 1952)
32class Gunzip : public Inflator
33{
34public:
35	typedef Inflator::Err Err;
36	class HeaderErr : public Err {public: HeaderErr() : Err(INVALID_DATA_FORMAT, "Gunzip: header decoding error") {}};
37	class TailErr : public Err {public: TailErr() : Err(INVALID_DATA_FORMAT, "Gunzip: tail too short") {}};
38	class CrcErr : public Err {public: CrcErr() : Err(DATA_INTEGRITY_CHECK_FAILED, "Gunzip: CRC check error") {}};
39	class LengthErr : public Err {public: LengthErr() : Err(DATA_INTEGRITY_CHECK_FAILED, "Gunzip: length check error") {}};
40
41	/*! \param repeat decompress multiple compressed streams in series
42		\param autoSignalPropagation 0 to turn off MessageEnd signal
43	*/
44	Gunzip(BufferedTransformation *attachment = NULL, bool repeat = false, int autoSignalPropagation = -1);
45
46protected:
47	enum {MAGIC1=0x1f, MAGIC2=0x8b,   // flags for the header
48		DEFLATED=8};
49
50	enum FLAG_MASKS {
51		CONTINUED=2, EXTRA_FIELDS=4, FILENAME=8, COMMENTS=16, ENCRYPTED=32};
52
53	unsigned int MaxPrestreamHeaderSize() const {return 1024;}
54	void ProcessPrestreamHeader();
55	void ProcessDecompressedData(const byte *string, size_t length);
56	unsigned int MaxPoststreamTailSize() const {return 8;}
57	void ProcessPoststreamTail();
58
59	word32 m_length;
60	CRC32 m_crc;
61};
62
63NAMESPACE_END
64
65#endif
66