Crypto++ 8.9 Free C++ class library of cryptographic schemes

gzip.h
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1 // gzip.h - originally written and placed in the public domain by Wei Dai
2
3 /// \file gzip.h
4 /// \brief GZIP compression and decompression (RFC 1952)
5
6 #ifndef CRYPTOPP_GZIP_H
7 #define CRYPTOPP_GZIP_H
8
9 #include "cryptlib.h"
10 #include "zdeflate.h"
11 #include "zinflate.h"
12 #include "crc.h"
13
14 NAMESPACE_BEGIN(CryptoPP)
15
16 /// \brief GZIP Compression (RFC 1952)
17 class Gzip : public Deflator
18 {
19 public:
20 /// \brief Construct a Gzip compressor
21 /// \param attachment an attached transformation
22 /// \param deflateLevel the deflate level
23 /// \param log2WindowSize the window size
24 /// \param detectUncompressible flag to detect if data is compressible
25 /// \details detectUncompressible makes it faster to process uncompressible files, but
26 /// if a file has both compressible and uncompressible parts, it may fail to compress
27 /// some of the compressible parts.
28 Gzip(BufferedTransformation *attachment=NULLPTR, unsigned int deflateLevel=DEFAULT_DEFLATE_LEVEL, unsigned int log2WindowSize=DEFAULT_LOG2_WINDOW_SIZE, bool detectUncompressible=true)
29 : Deflator(attachment, deflateLevel, log2WindowSize, detectUncompressible), m_totalLen(0), m_filetime(0) { }
30
31 /// \brief Construct a Gzip compressor
32 /// \param parameters a set of NameValuePairs to initialize this object
33 /// \param attachment an attached transformation
34 /// \details Possible parameter names: Log2WindowSize, DeflateLevel, DetectUncompressible
35 Gzip(const NameValuePairs &parameters, BufferedTransformation *attachment=NULLPTR)
36 : Deflator(parameters, attachment), m_totalLen(0), m_filetime(0)
37 {
38 IsolatedInitialize(parameters);
39 }
40
41 /// \param filetime the filetime to set in the header. The application is responsible for setting it.
42 void SetFiletime(word32 filetime) { m_filetime = filetime; }
43
44 /// \param filename the original filename to set in the header. The application is responsible for setting it.
45 /// RFC 1952 requires a ISO/IEC 8859-1 encoding.
46 /// \param throwOnEncodingError if throwOnEncodingError is true, then the filename is checked to ensure it is
47 /// ISO/IEC 8859-1 encoded. If the filename does not adhere to ISO/IEC 8859-1, then a InvalidDataFormat
48 /// is thrown. If throwOnEncodingError is false then the filename is not checked.
49 void SetFilename(const std::string& filename, bool throwOnEncodingError = false);
50
51 /// \param comment the comment to set in the header. The application is responsible for setting it.
52 /// RFC 1952 requires a ISO/IEC 8859-1 encoding.
53 /// \param throwOnEncodingError if throwOnEncodingError is true, then the comment is checked to ensure it is
54 /// ISO/IEC 8859-1 encoded. If the comment does not adhere to ISO/IEC 8859-1, then a InvalidDataFormat
55 /// is thrown. If throwOnEncodingError is false then the comment is not checked.
56 void SetComment(const std::string& comment, bool throwOnEncodingError = false);
57
58 void IsolatedInitialize(const NameValuePairs &parameters);
59
60 protected:
61 enum {MAGIC1=0x1f, MAGIC2=0x8b, // flags for the header
62 DEFLATED=8, FAST=4, SLOW=2};
63
64 enum FLAG_MASKS {
65 FILENAME=8, COMMENTS=16};
66
67 void WritePrestreamHeader();
68 void ProcessUncompressedData(const byte *string, size_t length);
69 void WritePoststreamTail();
70
71 word32 m_totalLen;
72 CRC32 m_crc;
73
74 word32 m_filetime;
75 std::string m_filename;
76 std::string m_comment;
77 };
78
79 /// \brief GZIP Decompression (RFC 1952)
80 class Gunzip : public Inflator
81 {
82 public:
83 typedef Inflator::Err Err;
84
85 /// \brief Exception thrown when a header decoding error occurs
86 class HeaderErr : public Err {public: HeaderErr() : Err(INVALID_DATA_FORMAT, "Gunzip: header decoding error") {}};
87 /// \brief Exception thrown when the tail is too short
88 class TailErr : public Err {public: TailErr() : Err(INVALID_DATA_FORMAT, "Gunzip: tail too short") {}};
89 /// \brief Exception thrown when a CRC error occurs
90 class CrcErr : public Err {public: CrcErr() : Err(DATA_INTEGRITY_CHECK_FAILED, "Gunzip: CRC check error") {}};
91 /// \brief Exception thrown when a length error occurs
92 class LengthErr : public Err {public: LengthErr() : Err(DATA_INTEGRITY_CHECK_FAILED, "Gunzip: length check error") {}};
93
94 /// \brief Construct a Gunzip decompressor
95 /// \param attachment an attached transformation
96 /// \param repeat decompress multiple compressed streams in series
97 /// \param autoSignalPropagation 0 to turn off MessageEnd signal
98 Gunzip(BufferedTransformation *attachment = NULLPTR, bool repeat = false, int autoSignalPropagation = -1);
99
100 /// \return the filetime of the stream as set in the header. The application is responsible for setting it on the decompressed file.
101 word32 GetFiletime() const { return m_filetime; }
102
103 /// \return the filename of the stream as set in the header. The application is responsible for setting it on the decompressed file.
104 /// \param throwOnEncodingError if throwOnEncodingError is true, then the filename is checked to ensure it is
105 /// ISO/IEC 8859-1 encoded. If the filename does not adhere to ISO/IEC 8859-1, then a InvalidDataFormat is thrown.
106 /// If throwOnEncodingError is false then the filename is not checked.
107 const std::string& GetFilename(bool throwOnEncodingError = false) const;
108
109 /// \return the comment of the stream as set in the header.
110 /// \param throwOnEncodingError if throwOnEncodingError is true, then the comment is checked to ensure it is
111 /// ISO/IEC 8859-1 encoded. If the comment does not adhere to ISO/IEC 8859-1, then a InvalidDataFormat is thrown.
112 /// If throwOnEncodingError is false then the comment is not checked.
113 const std::string& GetComment(bool throwOnEncodingError = false) const;
114
115 protected:
116 enum {
117 /// \brief First header magic value
118 MAGIC1=0x1f,
119 /// \brief Second header magic value
120 MAGIC2=0x8b,
121 /// \brief Deflated flag
122 DEFLATED=8
123 };
124
125 enum FLAG_MASKS {
126 CONTINUED=2, EXTRA_FIELDS=4, FILENAME=8, COMMENTS=16, ENCRYPTED=32};
127
128 unsigned int MaxPrestreamHeaderSize() const {return 1024;}
129 void ProcessPrestreamHeader();
130 void ProcessDecompressedData(const byte *string, size_t length);
131 unsigned int MaxPoststreamTailSize() const {return 8;}
132 void ProcessPoststreamTail();
133
134 word32 m_length;
135 CRC32 m_crc;
136
137 word32 m_filetime;
138 std::string m_filename;
139 std::string m_comment;
140 };
141
142 NAMESPACE_END
143
144 #endif
BufferedTransformation
Interface for buffered transformations.
Definition: cryptlib.h:1657
CRC32
CRC-32 Checksum Calculation.
Definition: crc.h:26
Deflator
DEFLATE compressor (RFC 1951)
Definition: zdeflate.h:76
Exception::INVALID_DATA_FORMAT
@ INVALID_DATA_FORMAT
Input data was received that did not conform to expected format.
Definition: cryptlib.h:178
Exception::DATA_INTEGRITY_CHECK_FAILED
@ DATA_INTEGRITY_CHECK_FAILED
Data integerity check, such as CRC or MAC, failed.
Definition: cryptlib.h:176
Gunzip::CrcErr
Exception thrown when a CRC error occurs.
Definition: gzip.h:90
Gunzip::HeaderErr
Exception thrown when a header decoding error occurs.
Definition: gzip.h:86
Gunzip::LengthErr
Exception thrown when a length error occurs.
Definition: gzip.h:92
Gunzip::TailErr
Exception thrown when the tail is too short.
Definition: gzip.h:88
Gunzip
GZIP Decompression (RFC 1952)
Definition: gzip.h:81
Gunzip::Gunzip
Gunzip(BufferedTransformation *attachment=NULL, bool repeat=false, int autoSignalPropagation=-1)
Construct a Gunzip decompressor.
Definition: gzip.cpp:105
Gunzip::GetFiletime
word32 GetFiletime() const
Definition: gzip.h:101
Gunzip::GetComment
const std::string & GetComment(bool throwOnEncodingError=false) const
Definition: gzip.cpp:180
Gunzip::GetFilename
const std::string & GetFilename(bool throwOnEncodingError=false) const
Definition: gzip.cpp:194
Gzip
GZIP Compression (RFC 1952)
Definition: gzip.h:18
Gzip::Gzip
Gzip(BufferedTransformation *attachment=NULL, unsigned int deflateLevel=DEFAULT_DEFLATE_LEVEL, unsigned int log2WindowSize=DEFAULT_LOG2_WINDOW_SIZE, bool detectUncompressible=true)
Construct a Gzip compressor.
Definition: gzip.h:28
Gzip::SetFiletime
void SetFiletime(word32 filetime)
Definition: gzip.h:42
Gzip::Gzip
Gzip(const NameValuePairs &parameters, BufferedTransformation *attachment=NULL)
Construct a Gzip compressor.
Definition: gzip.h:35
Inflator::Err
Definition: zinflate.h:98
Inflator
DEFLATE decompressor (RFC 1951)
Definition: zinflate.h:95
NameValuePairs
Interface for retrieving values given their names.
Definition: cryptlib.h:327
word32
unsigned int word32
32-bit unsigned datatype
Definition: config_int.h:72
crc.h
Classes for CRC-32 and CRC-32C checksum algorithm.
cryptlib.h
Abstract base classes that provide a uniform interface to this library.
CryptoPP
Crypto++ library namespace.
zdeflate.h
DEFLATE compression and decompression (RFC 1951)
zinflate.h
DEFLATE compression and decompression (RFC 1951)