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84 lines
2.7 KiB
84 lines
2.7 KiB
// mdc.h - originally written and placed in the public domain by Wei Dai |
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/// \file mdc.h |
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/// \brief Classes for the MDC message digest |
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#ifndef CRYPTOPP_MDC_H |
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#define CRYPTOPP_MDC_H |
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#include "seckey.h" |
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#include "secblock.h" |
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#include "misc.h" |
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// GCC cast warning |
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#define HashWordPtr(x) ((HashWordType*)(void*)(x)) |
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#define ConstHashWordPtr(x) ((const HashWordType*)(const void*)(x)) |
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NAMESPACE_BEGIN(CryptoPP) |
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/// \tparam B BlockCipher derived class |
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/// \brief MDC_Info cipher information |
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template <class B> |
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struct MDC_Info : public FixedBlockSize<B::DIGESTSIZE>, public FixedKeyLength<B::BLOCKSIZE> |
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{ |
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static std::string StaticAlgorithmName() {return std::string("MDC/")+B::StaticAlgorithmName();} |
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}; |
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/// \brief MDC cipher |
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/// \tparam H HashTransformation derived class |
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/// \details MDC() is a construction by Peter Gutmann to turn an iterated hash function into a PRF |
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/// \sa <a href="http://www.cryptopp.com/wiki/MDC">MDC</a> |
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template <class H> |
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class MDC : public MDC_Info<H> |
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{ |
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/// \brief MDC cipher encryption operation |
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class CRYPTOPP_NO_VTABLE Enc : public BlockCipherImpl<MDC_Info<H> > |
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{ |
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typedef typename H::HashWordType HashWordType; |
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public: |
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void UncheckedSetKey(const byte *userKey, unsigned int length, const NameValuePairs ¶ms) |
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{ |
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CRYPTOPP_UNUSED(params); |
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this->AssertValidKeyLength(length); |
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ConditionalByteReverse(BIG_ENDIAN_ORDER, Key(), ConstHashWordPtr(userKey), this->KEYLENGTH); |
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} |
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void ProcessAndXorBlock(const byte *inBlock, const byte *xorBlock, byte *outBlock) const |
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{ |
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ConditionalByteReverse(BIG_ENDIAN_ORDER, Buffer(), ConstHashWordPtr(inBlock), this->BLOCKSIZE); |
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H::Transform(Buffer(), Key()); |
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if (xorBlock) |
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{ |
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ConditionalByteReverse(BIG_ENDIAN_ORDER, Buffer(), Buffer(), this->BLOCKSIZE); |
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xorbuf(outBlock, xorBlock, m_buffer, this->BLOCKSIZE); |
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} |
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else |
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{ |
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ConditionalByteReverse(BIG_ENDIAN_ORDER, HashWordPtr(outBlock), Buffer(), this->BLOCKSIZE); |
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} |
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} |
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bool IsPermutation() const {return false;} |
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unsigned int OptimalDataAlignment() const {return sizeof(HashWordType);} |
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private: |
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HashWordType *Key() {return HashWordPtr(m_key.data());} |
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const HashWordType *Key() const {return ConstHashWordPtr(m_key.data());} |
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HashWordType *Buffer() const {return HashWordPtr(m_buffer.data());} |
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// VC60 workaround: bug triggered if using FixedSizeAllocatorWithCleanup |
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FixedSizeSecBlock<byte, MDC_Info<H>::KEYLENGTH, AllocatorWithCleanup<byte> > m_key; |
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mutable FixedSizeSecBlock<byte, MDC_Info<H>::BLOCKSIZE, AllocatorWithCleanup<byte> > m_buffer; |
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}; |
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public: |
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// use BlockCipher interface |
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typedef BlockCipherFinal<ENCRYPTION, Enc> Encryption; |
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}; |
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NAMESPACE_END |
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#endif
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