Crypto++
gzip.h
1 #ifndef CRYPTOPP_GZIP_H
2 #define CRYPTOPP_GZIP_H
3 
4 #include "zdeflate.h"
5 #include "zinflate.h"
6 #include "crc.h"
7 
8 NAMESPACE_BEGIN(CryptoPP)
9 
10 /// GZIP Compression (RFC 1952)
11 class Gzip : public Deflator
12 {
13 public:
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 
19 protected:
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)
32 class Gunzip : public Inflator
33 {
34 public:
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 
46 protected:
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 
63 NAMESPACE_END
64 
65 #endif
GZIP Decompression (RFC 1952)
Definition: gzip.h:32
DEFLATE (RFC 1951) compressor.
Definition: zdeflate.h:55
interface for buffered transformations
Definition: cryptlib.h:770
data integerity check (such as CRC or MAC) failed
Definition: cryptlib.h:121
Gunzip(BufferedTransformation *attachment=NULL, bool repeat=false, int autoSignalPropagation=-1)
received input data that doesn't conform to expected format
Definition: cryptlib.h:123
DEFLATE (RFC 1951) decompressor.
Definition: zinflate.h:85
GZIP Compression (RFC 1952)
Definition: gzip.h:11
CRC Checksum Calculation.
Definition: crc.h:19
interface for retrieving values given their names
Definition: cryptlib.h:224