60 lines
2.0 KiB
C++
60 lines
2.0 KiB
C++
// seal.h - originally written and placed in the public domain by Wei Dai
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/// \file seal.h
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/// \brief Classes for SEAL stream cipher
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/// \since Crypto++ 2.2
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#ifndef CRYPTOPP_SEAL_H
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#define CRYPTOPP_SEAL_H
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#include "strciphr.h"
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#include "secblock.h"
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NAMESPACE_BEGIN(CryptoPP)
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/// \brief SEAL stream cipher information
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/// \tparam B Endianness of the stream cipher
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/// \since Crypto++ 2.2
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template <class B = BigEndian>
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struct SEAL_Info : public FixedKeyLength<20, SimpleKeyingInterface::INTERNALLY_GENERATED_IV, 4>
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{
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CRYPTOPP_STATIC_CONSTEXPR const char* StaticAlgorithmName() {return B::ToEnum() == LITTLE_ENDIAN_ORDER ? "SEAL-3.0-LE" : "SEAL-3.0-BE";}
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};
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/// \brief SEAL stream cipher operation
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/// \tparam B Endianness of the stream cipher
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/// \since Crypto++ 2.2
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template <class B = BigEndian>
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class CRYPTOPP_NO_VTABLE SEAL_Policy : public AdditiveCipherConcretePolicy<word32, 256>, public SEAL_Info<B>
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{
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protected:
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void CipherSetKey(const NameValuePairs ¶ms, const byte *key, size_t length);
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void OperateKeystream(KeystreamOperation operation, byte *output, const byte *input, size_t iterationCount);
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void CipherResynchronize(byte *keystreamBuffer, const byte *IV, size_t length);
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bool CipherIsRandomAccess() const {return true;}
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void SeekToIteration(lword iterationCount);
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private:
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FixedSizeSecBlock<word32, 512> m_T;
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FixedSizeSecBlock<word32, 256> m_S;
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SecBlock<word32> m_R;
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word32 m_startCount, m_iterationsPerCount;
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word32 m_outsideCounter, m_insideCounter;
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};
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/// \brief SEAL stream cipher
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/// \tparam B Endianness of the stream cipher
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/// \sa <a href="http://www.cryptopp.com/wiki/SEAL-3.0-BE">SEAL</a>
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/// \since Crypto++ 2.2
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template <class B = BigEndian>
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struct SEAL : public SEAL_Info<B>, public SymmetricCipherDocumentation
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{
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typedef SymmetricCipherFinal<ConcretePolicyHolder<SEAL_Policy<B>, AdditiveCipherTemplate<> >, SEAL_Info<B> > Encryption;
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typedef Encryption Decryption;
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};
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NAMESPACE_END
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#endif
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