Crypto++ 8.2
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rng.h
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1// rng.h - originally written and placed in the public domain by Wei Dai
2
3/// \file rng.h
4/// \brief Miscellaneous classes for RNGs
5/// \details This file contains miscellaneous classes for RNGs, including LC_RNG(),
6/// X917RNG() and MaurerRandomnessTest()
7/// \sa osrng.h, randpool.h
8
9#ifndef CRYPTOPP_RNG_H
10#define CRYPTOPP_RNG_H
11
12#include "cryptlib.h"
13#include "filters.h"
14#include "smartptr.h"
15
16NAMESPACE_BEGIN(CryptoPP)
17
18/// \brief Linear Congruential Generator (LCG)
19/// \details Originally propsed by William S. England.
20/// \warning LC_RNG is suitable for simulations, where uniformaly distrubuted numbers are
21/// required quickly. It should not be used for cryptographic purposes.
23{
24public:
25 /// \brief Construct a Linear Congruential Generator (LCG)
26 /// \param init_seed the initial value for the generator
27 LC_RNG(word32 init_seed)
28 : seed(init_seed) {}
29
30 void GenerateBlock(byte *output, size_t size);
31
32 word32 GetSeed() {return seed;}
33
34private:
35 word32 seed;
36
37 static const word32 m;
38 static const word32 q;
39 static const word16 a;
40 static const word16 r;
41};
42
43/// \brief ANSI X9.17 RNG
44/// \details X917RNG is from ANSI X9.17 Appendix C, and it uses a 64-bit block cipher, like TripleDES.
45/// If you use a 128-bit block cipher, like AES, then you are effectively using an ANSI X9.31 generator.
46/// \sa AutoSeededX917RNG, DefaultAutoSeededRNG
47class CRYPTOPP_DLL X917RNG : public RandomNumberGenerator, public NotCopyable
48{
49public:
50 /// \brief Construct a X917RNG
51 /// \param cipher the block cipher to use for the generator
52 /// \param seed a byte buffer to use as a seed
53 /// \param deterministicTimeVector additional entropy
54 /// \details <tt>cipher</tt> will be deleted by the destructor. <tt>seed</tt> must be at least
55 /// BlockSize() in length. <tt>deterministicTimeVector = 0</tt> means obtain time vector
56 /// from the system.
57 /// \details When constructing a X917RNG, the generator must be keyed or an access
58 /// violation will occur because the time vector is encrypted using the block cipher.
59 /// To key the generator during constructions, perform the following:
60 /// <pre>
61 /// SecByteBlock key(AES::DEFAULT_KEYLENGTH), seed(AES::BLOCKSIZE);
62 /// OS_GenerateRandomBlock(false, key, key.size());
63 /// OS_GenerateRandomBlock(false, seed, seed.size());
64 /// X917RNG prng(new AES::Encryption(key, AES::DEFAULT_KEYLENGTH), seed, NULLPTR);</pre>
65 /// \sa AutoSeededX917RNG
66 X917RNG(BlockTransformation *cipher, const byte *seed, const byte *deterministicTimeVector = NULLPTR);
67
68 void GenerateIntoBufferedTransformation(BufferedTransformation &target, const std::string &channel, lword size);
69
70private:
72 const unsigned int m_size; // S, blocksize of cipher
73 SecByteBlock m_datetime; // DT, buffer for enciphered timestamp
74 SecByteBlock m_randseed, m_lastBlock, m_deterministicTimeVector;
75};
76
77/// \brief Maurer's Universal Statistical Test for Random Bit Generators
78/// \details This class implements Maurer's Universal Statistical Test for
79/// Random Bit Generators. It is intended for measuring the randomness of
80/// *PHYSICAL* RNGs.
81/// \details For more details see Maurer's paper in Journal of Cryptology, 1992.
82class MaurerRandomnessTest : public Bufferless<Sink>
83{
84public:
85 /// \brief Construct a MaurerRandomnessTest
87
88 size_t Put2(const byte *inString, size_t length, int messageEnd, bool blocking);
89
90 /// \brief Provides the number of bytes of input is needed by the test
91 /// \returns how many more bytes of input is needed by the test
92 // BytesNeeded() returns how many more bytes of input is needed by the test
93 // GetTestValue() should not be called before BytesNeeded()==0
94 unsigned int BytesNeeded() const {return n >= (Q+K) ? 0 : Q+K-n;}
95
96 // returns a number between 0.0 and 1.0, describing the quality of the
97 // random numbers entered
98 double GetTestValue() const;
99
100private:
101 enum {L=8, V=256, Q=2000, K=2000};
102 double sum;
103 unsigned int n;
104 unsigned int tab[V];
105};
106
107NAMESPACE_END
108
109#endif
Interface for the data processing part of block ciphers.
Definition: cryptlib.h:828
Interface for buffered transformations.
Definition: cryptlib.h:1599
Base class for bufferless filters.
Definition: simple.h:99
Linear Congruential Generator (LCG)
Definition: rng.h:23
LC_RNG(word32 init_seed)
Construct a Linear Congruential Generator (LCG)
Definition: rng.h:27
Maurer's Universal Statistical Test for Random Bit Generators.
Definition: rng.h:83
MaurerRandomnessTest()
Construct a MaurerRandomnessTest.
Definition: rng.cpp:136
unsigned int BytesNeeded() const
Provides the number of bytes of input is needed by the test.
Definition: rng.h:94
size_t Put2(const byte *inString, size_t length, int messageEnd, bool blocking)
Input multiple bytes for processing.
Definition: rng.cpp:143
Ensures an object is not copyable.
Definition: misc.h:201
Interface for random number generators.
Definition: cryptlib.h:1384
virtual void GenerateIntoBufferedTransformation(BufferedTransformation &target, const std::string &channel, lword length)
Generate random bytes into a BufferedTransformation.
Definition: cryptlib.cpp:324
SecBlock<byte> typedef.
Definition: secblock.h:1058
ANSI X9.17 RNG.
Definition: rng.h:48
Pointer that overloads operator ->
Definition: smartptr.h:37
Abstract base classes that provide a uniform interface to this library.
Implementation of BufferedTransformation's attachment interface.
Crypto++ library namespace.
Classes for automatic resource management.