source-engine/external/crypto++-5.61/rng.h
FluorescentCIAAfricanAmerican 3bf9df6b27 1
2020-04-22 12:56:21 -04:00

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C++

// rng.h - misc RNG related classes, see also osrng.h, randpool.h
#ifndef CRYPTOPP_RNG_H
#define CRYPTOPP_RNG_H
#include "cryptlib.h"
#include "filters.h"
NAMESPACE_BEGIN(CryptoPP)
//! linear congruential generator
/*! originally by William S. England, do not use for cryptographic purposes */
class LC_RNG : public RandomNumberGenerator
{
public:
LC_RNG(word32 init_seed)
: seed(init_seed) {}
void GenerateBlock(byte *output, size_t size);
word32 GetSeed() {return seed;}
private:
word32 seed;
static const word32 m;
static const word32 q;
static const word16 a;
static const word16 r;
};
//! RNG derived from ANSI X9.17 Appendix C
class CRYPTOPP_DLL X917RNG : public RandomNumberGenerator, public NotCopyable
{
public:
// cipher will be deleted by destructor, deterministicTimeVector = 0 means obtain time vector from system
X917RNG(BlockTransformation *cipher, const byte *seed, const byte *deterministicTimeVector = 0);
void GenerateIntoBufferedTransformation(BufferedTransformation &target, const std::string &channel, lword size);
private:
member_ptr<BlockTransformation> cipher;
unsigned int S; // blocksize of cipher
SecByteBlock dtbuf; // buffer for enciphered timestamp
SecByteBlock randseed, m_lastBlock, m_deterministicTimeVector;
};
/** This class implements Maurer's Universal Statistical Test for Random Bit Generators
it is intended for measuring the randomness of *PHYSICAL* RNGs.
For more details see his paper in Journal of Cryptology, 1992. */
class MaurerRandomnessTest : public Bufferless<Sink>
{
public:
MaurerRandomnessTest();
size_t Put2(const byte *inString, size_t length, int messageEnd, bool blocking);
// BytesNeeded() returns how many more bytes of input is needed by the test
// GetTestValue() should not be called before BytesNeeded()==0
unsigned int BytesNeeded() const {return n >= (Q+K) ? 0 : Q+K-n;}
// returns a number between 0.0 and 1.0, describing the quality of the
// random numbers entered
double GetTestValue() const;
private:
enum {L=8, V=256, Q=2000, K=2000};
double sum;
unsigned int n;
unsigned int tab[V];
};
NAMESPACE_END
#endif