1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
// gzip.h - originally written and placed in the public domain by Wei Dai
//! \file gzip.h
//! \brief GZIP compression and decompression (RFC 1952)
#ifndef CRYPTOPP_GZIP_H
#define CRYPTOPP_GZIP_H
#include "cryptlib.h"
#include "zdeflate.h"
#include "zinflate.h"
#include "crc.h"
NAMESPACE_BEGIN(CryptoPP)
//! \class Gzip
//! \brief GZIP Compression (RFC 1952)
class Gzip : public Deflator
{
public:
//! \brief Construct a Gzip compressor
//! \param attachment an attached transformation
//! \param deflateLevel the deflate level
//! \param log2WindowSize the window size
//! \param detectUncompressible flag to detect if data is compressible
//! \details detectUncompressible makes it faster to process uncompressible files, but
//! if a file has both compressible and uncompressible parts, it may fail to compress
//! some of the compressible parts.
Gzip(BufferedTransformation *attachment=NULLPTR, unsigned int deflateLevel=DEFAULT_DEFLATE_LEVEL, unsigned int log2WindowSize=DEFAULT_LOG2_WINDOW_SIZE, bool detectUncompressible=true)
: Deflator(attachment, deflateLevel, log2WindowSize, detectUncompressible), m_totalLen(0) { }
//! \brief Construct a Gzip compressor
//! \param parameters a set of NameValuePairs to initialize this object
//! \param attachment an attached transformation
//! \details Possible parameter names: Log2WindowSize, DeflateLevel, DetectUncompressible
Gzip(const NameValuePairs ¶meters, BufferedTransformation *attachment=NULLPTR)
: Deflator(parameters, attachment), m_totalLen(0)
{
IsolatedInitialize(parameters);
}
//! \param filetime the filetime to set in the header. The application is responsible for setting it.
void SetFiletime(word32 filetime) { m_filetime = filetime; }
//! \param filename the original filename to set in the header. The application is responsible for setting it.
//! RFC 1952 requires a ISO/IEC 8859-1 encoding.
//! \param throwOnEncodingError if throwOnEncodingError is true, then the filename is checked to ensure it is
//! ISO/IEC 8859-1 encoded. If the filename does not adhere to ISO/IEC 8859-1, then a InvalidDataFormat
//! is thrown. If throwOnEncodingError is false then the filename is not checked.
void SetFilename(const std::string& filename, bool throwOnEncodingError = false);
//! \param comment the comment to set in the header. The application is responsible for setting it.
//! RFC 1952 requires a ISO/IEC 8859-1 encoding.
//! \param throwOnEncodingError if throwOnEncodingError is true, then the comment is checked to ensure it is
//! ISO/IEC 8859-1 encoded. If the comment does not adhere to ISO/IEC 8859-1, then a InvalidDataFormat
//! is thrown. If throwOnEncodingError is false then the comment is not checked.
void SetComment(const std::string& comment, bool throwOnEncodingError = false);
void IsolatedInitialize(const NameValuePairs ¶meters);
protected:
enum {MAGIC1=0x1f, MAGIC2=0x8b, // flags for the header
DEFLATED=8, FAST=4, SLOW=2};
enum FLAG_MASKS {
FILENAME=8, COMMENTS=16};
void WritePrestreamHeader();
void ProcessUncompressedData(const byte *string, size_t length);
void WritePoststreamTail();
word32 m_totalLen;
CRC32 m_crc;
word32 m_filetime;
std::string m_filename;
std::string m_comment;
};
//! \class Gunzip
//! \brief GZIP Decompression (RFC 1952)
class Gunzip : public Inflator
{
public:
typedef Inflator::Err Err;
//! \class HeaderErr
//! \brief Exception thrown when a header decoding error occurs
class HeaderErr : public Err {public: HeaderErr() : Err(INVALID_DATA_FORMAT, "Gunzip: header decoding error") {}};
//! \class TailErr
//! \brief Exception thrown when the tail is too short
class TailErr : public Err {public: TailErr() : Err(INVALID_DATA_FORMAT, "Gunzip: tail too short") {}};
//! \class CrcErr
//! \brief Exception thrown when a CRC error occurs
class CrcErr : public Err {public: CrcErr() : Err(DATA_INTEGRITY_CHECK_FAILED, "Gunzip: CRC check error") {}};
//! \class LengthErr
//! \brief Exception thrown when a length error occurs
class LengthErr : public Err {public: LengthErr() : Err(DATA_INTEGRITY_CHECK_FAILED, "Gunzip: length check error") {}};
//! \brief Construct a Gunzip decompressor
//! \param attachment an attached transformation
//! \param repeat decompress multiple compressed streams in series
//! \param autoSignalPropagation 0 to turn off MessageEnd signal
Gunzip(BufferedTransformation *attachment = NULLPTR, bool repeat = false, int autoSignalPropagation = -1);
//! \return the filetime of the stream as set in the header. The application is responsible for setting it on the decompressed file.
word32 GetFiletime() const { return m_filetime; }
//! \return the filename of the stream as set in the header. The application is responsible for setting it on the decompressed file.
//! \param throwOnEncodingError if throwOnEncodingError is true, then the filename is checked to ensure it is
//! ISO/IEC 8859-1 encoded. If the filename does not adhere to ISO/IEC 8859-1, then a InvalidDataFormat is thrown.
//! If throwOnEncodingError is false then the filename is not checked.
const std::string& GetFilename(bool throwOnEncodingError = false) const;
//! \return the comment of the stream as set in the header.
//! \param throwOnEncodingError if throwOnEncodingError is true, then the comment is checked to ensure it is
//! ISO/IEC 8859-1 encoded. If the comment does not adhere to ISO/IEC 8859-1, then a InvalidDataFormat is thrown.
//! If throwOnEncodingError is false then the comment is not checked.
const std::string& GetComment(bool throwOnEncodingError = false) const;
protected:
enum {
//! \brief First header magic value
MAGIC1=0x1f,
//! \brief Second header magic value
MAGIC2=0x8b,
//! \brief Deflated flag
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;
word32 m_filetime;
std::string m_filename;
std::string m_comment;
};
NAMESPACE_END
#endif
|
