ext-cryptoppwin/include/cryptopp/randpool.h
Alexandre Bouvier 34dc3357ad fix include path
2024-06-24 12:33:59 +02:00

105 lines
4.5 KiB
C++

// randpool.h - originally written and placed in the public domain by Wei Dai
// OldRandPool added by JW in August, 2017.
/// \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 use OldRandomPool class. You
/// should migrate away from OldRandomPool at the earliest opportunity. Use RandomPool
/// or AutoSeededRandomPool instead.
/// \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)
/// \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.
/// \details You should reseed the generator after a fork() to avoid multiple generators
/// with the same internal state.
/// \details If you need the pre-Crypto++ 5.5 generator then use OldRandomPool class. You
/// should migrate away from OldRandomPool at the earliest opportunity.
/// \sa OldRandomPool
/// \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);
private:
FixedSizeAlignedSecBlock<byte, 16, true> m_seed;
FixedSizeAlignedSecBlock<byte, 32> m_key;
member_ptr<BlockCipher> m_pCipher;
bool m_keySet;
};
/// \brief Randomness Pool based on PGP 2.6.x with MDC
/// \details If you need the pre-Crypto++ 5.5 generator then use OldRandomPool class. The
/// OldRandomPool also provides the modern interface, including <tt>CanIncorporateEntropy</tt>,
/// <tt>IncorporateEntropy</tt> and <tt>GenerateIntoBufferedTransformation</tt>.
/// \details You should reseed the generator after a fork() to avoid multiple generators
/// with the same internal state.
/// \details You should migrate away from OldRandomPool at the earliest opportunity. Use a
/// modern random number generator or key derivation function, like AutoSeededRandomPool or
/// HKDF.
/// \warning This class uses an old style PGP 2.6.x with MDC. The generator risks reusing
/// random numbers after state rollback. You should migrate away from OldRandomPool at
/// the earliest opportunity.
/// \sa RandomPool, AutoSeededRandomPool, HKDF, P1363_KDF2, PKCS12_PBKDF, PKCS5_PBKDF2_HMAC
/// \since Crypto++ 6.0
class CRYPTOPP_DLL OldRandomPool : public RandomNumberGenerator
{
public:
/// \brief Construct an OldRandomPool
/// \param poolSize internal pool size of the generator
/// \details poolSize must be greater than 16
OldRandomPool(unsigned int poolSize=384);
// RandomNumberGenerator interface (Crypto++ 5.5 and above)
bool CanIncorporateEntropy() const {return true;}
void IncorporateEntropy(const byte *input, size_t length);
void GenerateIntoBufferedTransformation(BufferedTransformation &target, const std::string &channel, lword size);
byte GenerateByte();
void GenerateBlock(byte *output, size_t size);
// GenerateWord32 is overridden and provides Crypto++ 5.4 behavior.
// Taken from RandomNumberSource::GenerateWord32 in cryptlib.cpp.
word32 GenerateWord32 (word32 min=0, word32 max=0xffffffffUL);
protected:
void Stir();
private:
SecByteBlock pool, key;
size_t addPos, getPos;
};
NAMESPACE_END
#endif