// randpool.h - written and placed in the public domain by Wei Dai //! \file randpool.h //! \brief Class file for 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. At version 5.5 //! RandomPool was redesigned to reduce the risk of reusing random numbers after state //! rollback (which may occur when running in a virtual machine like VMware or a hosted //! environment). //! \details If you need the pre-Crypto++ 5.5 generator then you can find it with: //!
//!    $ git clone https://github.com/weidai11/cryptopp cryptopp-ancient
//!    $ cryptopp-ancient
//!
//!    # Checkout the RandomPool change
//!    $ git checkout f41245df6fb9b85574260eca9cd32777e8ab5136
//!
//!    # Go back one more
//!    git checkout HEAD~1
//!
//!    $ grep 'MDC' *.h *.cpp
//!    randpool.cpp:typedef MDC RandomPoolCipher;
//! 
//! \since Crypto++ 4.0 (PGP 2.6.x style), Crypto++ 5.5 (AES-256 based) #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) //! \class RandomPool //! \brief Randomness Pool based on AES-256 //! \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. At version 5.5 //! RandomPool was redesigned to reduce the risk of reusing random numbers after state //! rollback (which may occur when running in a virtual machine like VMware or a hosted //! environment). //! \since Crypto++ 4.0 (PGP 2.6.x style), Crypto++ 5.5 (AES-256 based) 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 m_seed; FixedSizeAlignedSecBlock m_key; member_ptr m_pCipher; bool m_keySet; }; NAMESPACE_END #endif