tiger.cpp

// tiger.cpp - written and placed in the public domain by Wei Dai

#include "pch.h"
#include "tiger.h"
#include "misc.h"

#ifdef WORD64_AVAILABLE

NAMESPACE_BEGIN(CryptoPP)

void Tiger::InitState(HashWordType *state)
{
        state[0] = W64LIT(0x0123456789ABCDEF);
        state[1] = W64LIT(0xFEDCBA9876543210);
        state[2] = W64LIT(0xF096A5B4C3B2E187);
}

void Tiger::TruncatedFinal(byte *hash, size_t size)
{
        ThrowIfInvalidTruncatedSize(size);

        PadLastBlock(56, 0x01);
        CorrectEndianess(m_data, m_data, 56);

        m_data[7] = GetBitCountLo();

        Transform(m_digest, m_data);
        CorrectEndianess(m_digest, m_digest, DigestSize());
        memcpy(hash, m_digest, size);

        Restart();              // reinit for next use
}

#define t1 (table)
#define t2 (table+256)
#define t3 (table+256*2)
#define t4 (table+256*3)

#define round(a,b,c,x,mul) \
        c ^= x; \
        a -= t1[GETBYTE(c,0)] ^ t2[GETBYTE(c,2)] ^ t3[GETBYTE(c,4)] ^ t4[GETBYTE(c,6)]; \
        b += t4[GETBYTE(c,1)] ^ t3[GETBYTE(c,3)] ^ t2[GETBYTE(c,5)] ^ t1[GETBYTE(c,7)]; \
        b *= mul

#define pass(a,b,c,mul,X) \
        round(a,b,c,X[0],mul); \
        round(b,c,a,X[1],mul); \
        round(c,a,b,X[2],mul); \
        round(a,b,c,X[3],mul); \
        round(b,c,a,X[4],mul); \
        round(c,a,b,X[5],mul); \
        round(a,b,c,X[6],mul); \
        round(b,c,a,X[7],mul)

#define key_schedule(Y,X) \
        Y[0] = X[0] - (X[7]^W64LIT(0xA5A5A5A5A5A5A5A5)); \
        Y[1] = X[1] ^ Y[0]; \
        Y[2] = X[2] + Y[1]; \
        Y[3] = X[3] - (Y[2] ^ ((~Y[1])<<19)); \
        Y[4] = X[4] ^ Y[3]; \
        Y[5] = X[5] + Y[4]; \
        Y[6] = X[6] - (Y[5] ^ ((~Y[4])>>23)); \
        Y[7] = X[7] ^ Y[6]; \
        Y[0] += Y[7]; \
        Y[1] -= Y[0] ^ ((~Y[7])<<19); \
        Y[2] ^= Y[1]; \
        Y[3] += Y[2]; \
        Y[4] -= Y[3] ^ ((~Y[2])>>23); \
        Y[5] ^= Y[4]; \
        Y[6] += Y[5]; \
        Y[7] -= Y[6] ^ W64LIT(0x0123456789ABCDEF)

void Tiger::Transform (word64 *digest, const word64 *X)
{
        word64 a = digest[0];
        word64 b = digest[1];
        word64 c = digest[2];
        word64 Y[8];

        pass(a,b,c,5,X);
        key_schedule(Y,X);
        pass(c,a,b,7,Y);
        key_schedule(Y,Y);
        pass(b,c,a,9,Y);

        digest[0] = a ^ digest[0];
        digest[1] = b - digest[1];
        digest[2] = c + digest[2];

        memset(Y, 0, sizeof(Y));
}

NAMESPACE_END

#endif  // WORD64_AVAILABLE

---