ext-cryptopp/seal.h
2015-11-22 19:17:15 -05:00

51 lines
1.6 KiB
C++

// seal.h - written and placed in the public domain by Wei Dai
//! \file seal.h
//! \brief Classes for SEAL stream cipher
#ifndef CRYPTOPP_SEAL_H
#define CRYPTOPP_SEAL_H
#include "strciphr.h"
#include "secblock.h"
NAMESPACE_BEGIN(CryptoPP)
//! _
template <class B = BigEndian>
struct SEAL_Info : public FixedKeyLength<20, SimpleKeyingInterface::INTERNALLY_GENERATED_IV, 4>
{
static const char *StaticAlgorithmName() {return B::ToEnum() == LITTLE_ENDIAN_ORDER ? "SEAL-3.0-LE" : "SEAL-3.0-BE";}
};
template <class B = BigEndian>
class CRYPTOPP_NO_VTABLE SEAL_Policy : public AdditiveCipherConcretePolicy<word32, 256>, public SEAL_Info<B>
{
protected:
void CipherSetKey(const NameValuePairs &params, const byte *key, size_t length);
void OperateKeystream(KeystreamOperation operation, byte *output, const byte *input, size_t iterationCount);
void CipherResynchronize(byte *keystreamBuffer, const byte *IV, size_t length);
bool CipherIsRandomAccess() const {return true;}
void SeekToIteration(lword iterationCount);
private:
FixedSizeSecBlock<word32, 512> m_T;
FixedSizeSecBlock<word32, 256> m_S;
SecBlock<word32> m_R;
word32 m_startCount, m_iterationsPerCount;
word32 m_outsideCounter, m_insideCounter;
};
//! <a href="http://www.weidai.com/scan-mirror/cs.html#SEAL-3.0-BE">SEAL</a>
template <class B = BigEndian>
struct SEAL : public SEAL_Info<B>, public SymmetricCipherDocumentation
{
typedef SymmetricCipherFinal<ConcretePolicyHolder<SEAL_Policy<B>, AdditiveCipherTemplate<> >, SEAL_Info<B> > Encryption;
typedef Encryption Decryption;
};
NAMESPACE_END
#endif