Crypto++  5.6.5
Free C++ class library of cryptographic schemes
zinflate.h
1 #ifndef CRYPTOPP_ZINFLATE_H
2 #define CRYPTOPP_ZINFLATE_H
3 
4 #include "cryptlib.h"
5 #include "secblock.h"
6 #include "filters.h"
7 #include "stdcpp.h"
8 
9 NAMESPACE_BEGIN(CryptoPP)
10 
11 /// \since Crypto++ 1.0
13 {
14 public:
15  LowFirstBitReader(BufferedTransformation &store)
16  : m_store(store), m_buffer(0), m_bitsBuffered(0) {}
17  unsigned int BitsBuffered() const {return m_bitsBuffered;}
18  unsigned long PeekBuffer() const {return m_buffer;}
19  bool FillBuffer(unsigned int length);
20  unsigned long PeekBits(unsigned int length);
21  void SkipBits(unsigned int length);
22  unsigned long GetBits(unsigned int length);
23 
24 private:
25  BufferedTransformation &m_store;
26  unsigned long m_buffer;
27  unsigned int m_bitsBuffered;
28 };
29 
30 struct CodeLessThan;
31 
32 /// \brief Huffman Decoder
33 /// \since Crypto++ 1.0
35 {
36 public:
37  typedef unsigned int code_t;
38  typedef unsigned int value_t;
39  enum {MAX_CODE_BITS = sizeof(code_t)*8};
40 
41  class Err : public Exception {public: Err(const std::string &what) : Exception(INVALID_DATA_FORMAT, "HuffmanDecoder: " + what) {}};
42 
43  HuffmanDecoder() : m_maxCodeBits(0), m_cacheBits(0), m_cacheMask(0), m_normalizedCacheMask(0) {}
44  HuffmanDecoder(const unsigned int *codeBitLengths, unsigned int nCodes)
45  : m_maxCodeBits(0), m_cacheBits(0), m_cacheMask(0), m_normalizedCacheMask(0)
46  {Initialize(codeBitLengths, nCodes);}
47 
48  void Initialize(const unsigned int *codeBitLengths, unsigned int nCodes);
49  unsigned int Decode(code_t code, /* out */ value_t &value) const;
50  bool Decode(LowFirstBitReader &reader, value_t &value) const;
51 
52 private:
53  friend struct CodeLessThan;
54 
55  struct CodeInfo
56  {
57  CodeInfo(code_t code=0, unsigned int len=0, value_t value=0) : code(code), len(len), value(value) {}
58  inline bool operator<(const CodeInfo &rhs) const {return code < rhs.code;}
59  code_t code;
60  unsigned int len;
61  value_t value;
62  };
63 
64  struct LookupEntry
65  {
66  unsigned int type;
67  union
68  {
69  value_t value;
70  const CodeInfo *begin;
71  };
72  union
73  {
74  unsigned int len;
75  const CodeInfo *end;
76  };
77  };
78 
79  static code_t NormalizeCode(code_t code, unsigned int codeBits);
80  void FillCacheEntry(LookupEntry &entry, code_t normalizedCode) const;
81 
82  unsigned int m_maxCodeBits, m_cacheBits, m_cacheMask, m_normalizedCacheMask;
83  std::vector<CodeInfo, AllocatorWithCleanup<CodeInfo> > m_codeToValue;
84  mutable std::vector<LookupEntry, AllocatorWithCleanup<LookupEntry> > m_cache;
85 };
86 
87 /// \brief DEFLATE decompressor (RFC 1951)
88 /// \since Crypto++ 1.0
89 class Inflator : public AutoSignaling<Filter>
90 {
91 public:
92  class Err : public Exception
93  {
94  public:
95  Err(ErrorType e, const std::string &s)
96  : Exception(e, s) {}
97  };
98  /// \brief Exception thrown when a truncated stream is encountered
99  class UnexpectedEndErr : public Err {public: UnexpectedEndErr() : Err(INVALID_DATA_FORMAT, "Inflator: unexpected end of compressed block") {}};
100  /// \brief Exception thrown when a bad block is encountered
101  class BadBlockErr : public Err {public: BadBlockErr() : Err(INVALID_DATA_FORMAT, "Inflator: error in compressed block") {}};
102  /// \brief Exception thrown when an invalid distance is encountered
103  class BadDistanceErr : public Err {public: BadDistanceErr() : Err(INVALID_DATA_FORMAT, "Inflator: error in bit distance") {}};
104 
105  /// \brief RFC 1951 Decompressor
106  /// \param attachment the filter's attached transformation
107  /// \param repeat decompress multiple compressed streams in series
108  /// \param autoSignalPropagation 0 to turn off MessageEnd signal
109  Inflator(BufferedTransformation *attachment = NULLPTR, bool repeat = false, int autoSignalPropagation = -1);
110 
111  void IsolatedInitialize(const NameValuePairs &parameters);
112  size_t Put2(const byte *inString, size_t length, int messageEnd, bool blocking);
113  bool IsolatedFlush(bool hardFlush, bool blocking);
114 
115  virtual unsigned int GetLog2WindowSize() const {return 15;}
116 
117 protected:
118  ByteQueue m_inQueue;
119 
120 private:
121  virtual unsigned int MaxPrestreamHeaderSize() const {return 0;}
122  virtual void ProcessPrestreamHeader() {}
123  virtual void ProcessDecompressedData(const byte *string, size_t length)
124  {AttachedTransformation()->Put(string, length);}
125  virtual unsigned int MaxPoststreamTailSize() const {return 0;}
126  virtual void ProcessPoststreamTail() {}
127 
128  void ProcessInput(bool flush);
129  void DecodeHeader();
130  bool DecodeBody();
131  void FlushOutput();
132  void OutputByte(byte b);
133  void OutputString(const byte *string, size_t length);
134  void OutputPast(unsigned int length, unsigned int distance);
135 
136  static const HuffmanDecoder *FixedLiteralDecoder();
137  static const HuffmanDecoder *FixedDistanceDecoder();
138 
139  const HuffmanDecoder& GetLiteralDecoder() const;
140  const HuffmanDecoder& GetDistanceDecoder() const;
141 
142  enum State {PRE_STREAM, WAIT_HEADER, DECODING_BODY, POST_STREAM, AFTER_END};
143  State m_state;
144  bool m_repeat, m_eof, m_wrappedAround;
145  byte m_blockType;
146  word16 m_storedLen;
147  enum NextDecode {LITERAL, LENGTH_BITS, DISTANCE, DISTANCE_BITS};
148  NextDecode m_nextDecode;
149  unsigned int m_literal, m_distance; // for LENGTH_BITS or DISTANCE_BITS
150  HuffmanDecoder m_dynamicLiteralDecoder, m_dynamicDistanceDecoder;
151  LowFirstBitReader m_reader;
152  SecByteBlock m_window;
153  size_t m_current, m_lastFlush;
154 };
155 
156 NAMESPACE_END
157 
158 #endif
Base class for all exceptions thrown by the library.
Definition: cryptlib.h:156
ErrorType
Error types or categories.
Definition: cryptlib.h:161
const char * what() const
Retrieves a C-string describing the exception.
Definition: cryptlib.h:184
Exception thrown when a truncated stream is encountered.
Definition: zinflate.h:99
Exception(ErrorType errorType, const std::string &s)
Construct a new Exception.
Definition: cryptlib.h:181
Abstract base classes that provide a uniform interface to this library.
SecBlock<byte> typedef.
Definition: secblock.h:822
Interface for buffered transformations.
Definition: cryptlib.h:1472
Classes and functions for secure memory allocations.
Input data was received that did not conform to expected format.
Definition: cryptlib.h:171
bool operator<(const OID &lhs, const OID &rhs)
Compare two OIDs for ordering.
size_t Put(byte inByte, bool blocking=true)
Input a byte for processing.
Definition: cryptlib.h:1494
Exception thrown when an invalid distance is encountered.
Definition: zinflate.h:103
Huffman Decoder.
Definition: zinflate.h:34
Data structure used to store byte strings.
Definition: queue.h:18
Implementation of BufferedTransformation&#39;s attachment interface.
DEFLATE decompressor (RFC 1951)
Definition: zinflate.h:89
Provides auto signaling support.
Definition: simple.h:282
Crypto++ library namespace.
Exception thrown when a bad block is encountered.
Definition: zinflate.h:101
Interface for retrieving values given their names.
Definition: cryptlib.h:291