ext-cryptopp/randpool.h
2016-01-24 23:09:28 -05:00

48 lines
1.6 KiB
C++

// randpool.h - written and placed in the public domain by Wei Dai
//! \file randpool.h
//! \brief Class file for Randomness Pool
#ifndef CRYPTOPP_RANDPOOL_H
#define CRYPTOPP_RANDPOOL_H
#include "cryptlib.h"
#include "filters.h"
#include "secblock.h"
#include "smartptr.h"
#include "aes.h"
NAMESPACE_BEGIN(CryptoPP)
//! \brief Randomness Pool
//! \details RandomPool can be used to generate cryptographic quality pseudorandom bytes
//! after seeding the pool with IncorporateEntropy(). Internally, the generator uses
//! AES-256 to produce the stream. Entropy is stirred in using SHA-256.
//! \details RandomPool used to follow the design of randpool in PGP 2.6.x,
//! but as of version 5.5 it has been redesigned to reduce the risk
//! of reusing random numbers after state rollback (which may occur
//! when running in a virtual machine like VMware).
class CRYPTOPP_DLL RandomPool : public RandomNumberGenerator, public NotCopyable
{
public:
//! \brief Construct a RandomPool
RandomPool();
bool CanIncorporateEntropy() const {return true;}
void IncorporateEntropy(const byte *input, size_t length);
void GenerateIntoBufferedTransformation(BufferedTransformation &target, const std::string &channel, lword size);
// for backwards compatibility. use RandomNumberSource, RandomNumberStore, and RandomNumberSink for other BufferTransformation functionality
void Put(const byte *input, size_t length) {IncorporateEntropy(input, length);}
private:
FixedSizeAlignedSecBlock<byte, 16, true> m_seed;
FixedSizeAlignedSecBlock<byte, 32> m_key;
member_ptr<BlockCipher> m_pCipher;
bool m_keySet;
};
NAMESPACE_END
#endif