Crypto++ 8.1 Free C++ class library of cryptographic schemes

basecode.h
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1 // basecode.h - originally written and placed in the public domain by Wei Dai
2
3 /// \file
4 /// \brief Base classes for working with encoders and decoders.
5
6 #ifndef CRYPTOPP_BASECODE_H
7 #define CRYPTOPP_BASECODE_H
8
9 #include "cryptlib.h"
10 #include "filters.h"
11 #include "algparam.h"
12 #include "argnames.h"
13
14 NAMESPACE_BEGIN(CryptoPP)
15
16 /// \brief Encoder for bases that are a power of 2
17 class CRYPTOPP_DLL BaseN_Encoder : public Unflushable<Filter>
18 {
19 public:
20 /// \brief Construct a BaseN_Encoder
21 /// \param attachment a BufferedTransformation to attach to this object
22 BaseN_Encoder(BufferedTransformation *attachment=NULLPTR)
23 : m_alphabet(NULLPTR), m_padding(0), m_bitsPerChar(0)
24 , m_outputBlockSize(0), m_bytePos(0), m_bitPos(0)
25 {Detach(attachment);}
26
27 /// \brief Construct a BaseN_Encoder
28 /// \param alphabet table of ASCII characters to use as the alphabet
29 /// \param log2base the log<sub>2</sub>base
30 /// \param attachment a BufferedTransformation to attach to this object
31 /// \param padding the character to use as padding
32 /// \pre log2base must be between 1 and 7 inclusive
33 /// \throws InvalidArgument if log2base is not between 1 and 7
34 BaseN_Encoder(const byte *alphabet, int log2base, BufferedTransformation *attachment=NULLPTR, int padding=-1)
35 : m_alphabet(NULLPTR), m_padding(0), m_bitsPerChar(0)
36 , m_outputBlockSize(0), m_bytePos(0), m_bitPos(0)
37 {
38 Detach(attachment);
39 IsolatedInitialize(MakeParameters(Name::EncodingLookupArray(), alphabet)
40 (Name::Log2Base(), log2base)
41 (Name::Pad(), padding != -1)
42 (Name::PaddingByte(), byte(padding)));
43 }
44
45 void IsolatedInitialize(const NameValuePairs &parameters);
46 size_t Put2(const byte *begin, size_t length, int messageEnd, bool blocking);
47
48 private:
49 const byte *m_alphabet;
50 int m_padding, m_bitsPerChar, m_outputBlockSize;
51 int m_bytePos, m_bitPos;
52 SecByteBlock m_outBuf;
53 };
54
55 /// \brief Decoder for bases that are a power of 2
56 class CRYPTOPP_DLL BaseN_Decoder : public Unflushable<Filter>
57 {
58 public:
59 /// \brief Construct a BaseN_Decoder
60 /// \param attachment a BufferedTransformation to attach to this object
61 /// \details padding is set to -1, which means use default padding. If not
62 /// required, then the value must be set via IsolatedInitialize().
63 BaseN_Decoder(BufferedTransformation *attachment=NULLPTR)
64 : m_lookup(NULLPTR), m_bitsPerChar(0)
65 , m_outputBlockSize(0), m_bytePos(0), m_bitPos(0)
66 {Detach(attachment);}
67
68 /// \brief Construct a BaseN_Decoder
69 /// \param lookup table of values
70 /// \param log2base the log<sub>2</sub>base
71 /// \param attachment a BufferedTransformation to attach to this object
72 /// \details log2base is the exponent (like 5 in 2<sup>5</sup>), and not
73 /// the number of elements (like 32).
74 /// \details padding is set to -1, which means use default padding. If not
75 /// required, then the value must be set via IsolatedInitialize().
76 BaseN_Decoder(const int *lookup, int log2base, BufferedTransformation *attachment=NULLPTR)
77 : m_lookup(NULLPTR), m_bitsPerChar(0)
78 , m_outputBlockSize(0), m_bytePos(0), m_bitPos(0)
79 {
80 Detach(attachment);
81 IsolatedInitialize(MakeParameters(Name::DecodingLookupArray(), lookup)(Name::Log2Base(), log2base));
82 }
83
84 void IsolatedInitialize(const NameValuePairs &parameters);
85 size_t Put2(const byte *begin, size_t length, int messageEnd, bool blocking);
86
87 /// \brief Initializes BaseN lookup array
88 /// \param lookup table of values
89 /// \param alphabet table of ASCII characters
90 /// \param base the base for the encoder
91 /// \param caseInsensitive flag indicating whether the alphabet is case sensitivie
92 /// \pre COUNTOF(lookup) == 256
93 /// \pre COUNTOF(alphabet) == base
94 /// \details Internally, the function sets the first 256 elements in the lookup table to
95 /// their value from the alphabet array or -1. base is the number of element (like 32),
96 /// and not an exponent (like 5 in 2<sup>5</sup>)
97 static void CRYPTOPP_API InitializeDecodingLookupArray(int *lookup, const byte *alphabet, unsigned int base, bool caseInsensitive);
98
99 private:
100 const int *m_lookup;
101 int m_bitsPerChar, m_outputBlockSize;
102 int m_bytePos, m_bitPos;
103 SecByteBlock m_outBuf;
104 };
105
106 /// \brief Filter that breaks input stream into groups of fixed size
107 class CRYPTOPP_DLL Grouper : public Bufferless<Filter>
108 {
109 public:
110 /// \brief Construct a Grouper
111 /// \param attachment a BufferedTransformation to attach to this object
112 Grouper(BufferedTransformation *attachment=NULLPTR)
113 : m_groupSize(0), m_counter(0) {Detach(attachment);}
114
115 /// \brief Construct a Grouper
116 /// \param groupSize the size of the grouping
117 /// \param separator the separator to use between groups
118 /// \param terminator the terminator appeand after processing
119 /// \param attachment a BufferedTransformation to attach to this object
120 Grouper(int groupSize, const std::string &separator, const std::string &terminator, BufferedTransformation *attachment=NULLPTR)
121 : m_groupSize(0), m_counter(0)
122 {
123 Detach(attachment);
124 IsolatedInitialize(MakeParameters(Name::GroupSize(), groupSize)
125 (Name::Separator(), ConstByteArrayParameter(separator))
126 (Name::Terminator(), ConstByteArrayParameter(terminator)));
127 }
128
129 void IsolatedInitialize(const NameValuePairs &parameters);
130 size_t Put2(const byte *begin, size_t length, int messageEnd, bool blocking);
131
132 private:
133 SecByteBlock m_separator, m_terminator;
134 size_t m_groupSize, m_counter;
135 };
136
137 NAMESPACE_END
138
139 #endif
ConstByteArrayParameter
Used to pass byte array input as part of a NameValuePairs object.
Definition: algparam.h:20
argnames.h
Standard names for retrieving values by name when working with NameValuePairs.
algparam.h
Classes for working with NameValuePairs.
Name::Pad
const char * Pad()
bool
Definition: argnames.h:72
Grouper::Grouper
Grouper(BufferedTransformation *attachment=NULL)
Construct a Grouper.
Definition: basecode.h:112
Grouper::Grouper
Grouper(int groupSize, const std::string &separator, const std::string &terminator, BufferedTransformation *attachment=NULL)
Construct a Grouper.
Definition: basecode.h:120
cryptlib.h
Abstract base classes that provide a uniform interface to this library.
BaseN_Encoder::BaseN_Encoder
BaseN_Encoder(BufferedTransformation *attachment=NULL)
Construct a BaseN_Encoder.
Definition: basecode.h:22
SecByteBlock
SecBlock<byte> typedef.
Definition: secblock.h:1058
BufferedTransformation
Interface for buffered transformations.
Definition: cryptlib.h:1598
Name::PaddingByte
const char * PaddingByte()
byte
Definition: argnames.h:73
Name::Separator
const char * Separator()
ConstByteArrayParameter.
Definition: argnames.h:68
BaseN_Decoder::BaseN_Decoder
BaseN_Decoder(BufferedTransformation *attachment=NULL)
Construct a BaseN_Decoder.
Definition: basecode.h:63
MakeParameters
AlgorithmParameters MakeParameters(const char *name, const T &value, bool throwIfNotUsed=true)
Create an object that implements NameValuePairs.
Definition: algparam.h:502
Name::EncodingLookupArray
const char * EncodingLookupArray()
const byte *
Definition: argnames.h:75
BaseN_Decoder::BaseN_Decoder
BaseN_Decoder(const int *lookup, int log2base, BufferedTransformation *attachment=NULL)
Construct a BaseN_Decoder.
Definition: basecode.h:76
Name::Log2Base
const char * Log2Base()
int
Definition: argnames.h:74
Name::GroupSize
const char * GroupSize()
int
Definition: argnames.h:71
Name::Terminator
const char * Terminator()
ConstByteArrayParameter.
Definition: argnames.h:69
filters.h
Implementation of BufferedTransformation&#39;s attachment interface.
BaseN_Encoder::BaseN_Encoder
BaseN_Encoder(const byte *alphabet, int log2base, BufferedTransformation *attachment=NULL, int padding=-1)
Construct a BaseN_Encoder.
Definition: basecode.h:34
Unflushable
Base class for unflushable filters.
Definition: simple.h:108
Name::DecodingLookupArray
const char * DecodingLookupArray()
const byte *
Definition: argnames.h:76
Filter
Implementation of BufferedTransformation&#39;s attachment interface.
Definition: filters.h:35
Grouper
Filter that breaks input stream into groups of fixed size.
Definition: basecode.h:107
CryptoPP
Crypto++ library namespace.
BaseN_Encoder
Encoder for bases that are a power of 2.
Definition: basecode.h:17
BaseN_Decoder
Decoder for bases that are a power of 2.
Definition: basecode.h:56
Bufferless
Base class for bufferless filters.
Definition: simple.h:98
NameValuePairs
Interface for retrieving values given their names.
Definition: cryptlib.h:293