vmac.h

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// vmac.h - written and placed in the public domain by Wei Dai


#ifndef CRYPTOPP_VMAC_H
#define CRYPTOPP_VMAC_H

#include "cryptlib.h"
#include "iterhash.h"
#include "seckey.h"

// Clang 3.3 integrated assembler crash on Linux
//  http://github.com/weidai11/cryptopp/issues/264
#if (defined(CRYPTOPP_LLVM_CLANG_VERSION) && (CRYPTOPP_LLVM_CLANG_VERSION < 30400)) || CRYPTOPP_BOOL_X32
# define CRYPTOPP_DISABLE_VMAC_ASM
#endif

NAMESPACE_BEGIN(CryptoPP)

class VMAC_Base : public IteratedHashBase<word64, MessageAuthenticationCode>
{
public:
        std::string AlgorithmName() const {return std::string("VMAC(") + GetCipher().AlgorithmName() + ")-" + IntToString(DigestSize()*8);}
        unsigned int IVSize() const {return GetCipher().BlockSize();}
        unsigned int MinIVLength() const {return 1;}
        void Resynchronize(const byte *nonce, int length=-1);
        void GetNextIV(RandomNumberGenerator &rng, byte *IV);
        unsigned int DigestSize() const {return m_is128 ? 16 : 8;};
        void UncheckedSetKey(const byte *userKey, unsigned int keylength, const NameValuePairs &params);
        void TruncatedFinal(byte *mac, size_t size);
        unsigned int BlockSize() const {return m_L1KeyLength;}
        ByteOrder GetByteOrder() const {return LITTLE_ENDIAN_ORDER;}
        unsigned int OptimalDataAlignment() const;

protected:
        virtual BlockCipher & AccessCipher() =0;
        virtual int DefaultDigestSize() const =0;
        const BlockCipher & GetCipher() const {return const_cast<VMAC_Base *>(this)->AccessCipher();}
        void HashEndianCorrectedBlock(const word64 *data);
        size_t HashMultipleBlocks(const word64 *input, size_t length);
        void Init() {}
        word64* StateBuf() {return NULL;}
        word64* DataBuf() {return (word64 *)(void*)m_data();}

        void VHASH_Update_SSE2(const word64 *data, size_t blocksRemainingInWord64, int tagPart);
        template <bool T_128BitTag>
                void VHASH_Update_Template(const word64 *data, size_t blockRemainingInWord128);
        void VHASH_Update(const word64 *data, size_t blocksRemainingInWord128);

        CRYPTOPP_BLOCK_1(polyState, word64, 4*(m_is128+1))
        CRYPTOPP_BLOCK_2(nhKey, word64, m_L1KeyLength/sizeof(word64) + 2*m_is128)
        CRYPTOPP_BLOCK_3(data, byte, m_L1KeyLength)
        CRYPTOPP_BLOCK_4(l3Key, word64, 2*(m_is128+1))
        CRYPTOPP_BLOCK_5(nonce, byte, IVSize())
        CRYPTOPP_BLOCK_6(pad, byte, IVSize())
        CRYPTOPP_BLOCKS_END(6)

        bool m_is128, m_padCached, m_isFirstBlock;
        unsigned int m_L1KeyLength;
};

template <class T_BlockCipher, int T_DigestBitSize = 128>
class VMAC : public SimpleKeyingInterfaceImpl<VMAC_Base, SameKeyLengthAs<T_BlockCipher, SimpleKeyingInterface::UNIQUE_IV, T_BlockCipher::BLOCKSIZE> >
{
public:
        static std::string StaticAlgorithmName() {return std::string("VMAC(") + T_BlockCipher::StaticAlgorithmName() + ")-" + IntToString(T_DigestBitSize);}

private:
        BlockCipher & AccessCipher() {return m_cipher;}
        int DefaultDigestSize() const {return T_DigestBitSize/8;}
        typename T_BlockCipher::Encryption m_cipher;
};

NAMESPACE_END

#endif