panama.cpp

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

#include "pch.h"
#include "panama.h"
#include "misc.h"

NAMESPACE_BEGIN(CryptoPP)

template <class B>
void Panama<B>::Reset()
{
        m_bstart = 0;
        memset(m_state, 0, m_state.size()*4);
}

template <class B>
void Panama<B>::Iterate(size_t count, const word32 *p, word32 *z, const word32 *y)
{
        unsigned int bstart = m_bstart;
        word32 *const a = m_state;
#define c (a+17)
#define b ((Stage *)(a+34))

// output
#define OA(i) z[i] = ConditionalByteReverse(B::ToEnum(), a[i+9])
#define OX(i) z[i] = y[i] ^ ConditionalByteReverse(B::ToEnum(), a[i+9])
// buffer update
#define US(i) {word32 t=b0[i]; b0[i]=ConditionalByteReverse(B::ToEnum(), p[i])^t; b25[(i+6)%8]^=t;}
#define UL(i) {word32 t=b0[i]; b0[i]=a[i+1]^t; b25[(i+6)%8]^=t;}
// gamma and pi
#define GP(i) c[5*i%17] = rotlFixed(a[i] ^ (a[(i+1)%17] | ~a[(i+2)%17]), ((5*i%17)*((5*i%17)+1)/2)%32)
// theta and sigma
#define T(i,x) a[i] = c[i] ^ c[(i+1)%17] ^ c[(i+4)%17] ^ x
#define TS1S(i) T(i+1, ConditionalByteReverse(B::ToEnum(), p[i]))
#define TS1L(i) T(i+1, b4[i])
#define TS2(i) T(i+9, b16[i])

        while (count--)
        {
                if (z)
                {
                        if (y)
                        {
                                OX(0); OX(1); OX(2); OX(3); OX(4); OX(5); OX(6); OX(7);
                                y += 8;
                        }
                        else
                        {
                                OA(0); OA(1); OA(2); OA(3); OA(4); OA(5); OA(6); OA(7);
                        }
                        z += 8;
                }

                word32 *const b16 = b[(bstart+16) % STAGES];
                word32 *const b4 = b[(bstart+4) % STAGES];
        bstart = (bstart + STAGES - 1) % STAGES;
                word32 *const b0 = b[bstart];
                word32 *const b25 = b[(bstart+25) % STAGES];


                if (p)
                {
                        US(0); US(1); US(2); US(3); US(4); US(5); US(6); US(7);
                }
                else
                {
                        UL(0); UL(1); UL(2); UL(3); UL(4); UL(5); UL(6); UL(7);
                }

                GP(0); GP(1); GP(2); GP(3); GP(4); GP(5); GP(6); GP(7);
                GP(8); GP(9); GP(10); GP(11); GP(12); GP(13); GP(14); GP(15); GP(16);

                T(0,1);

                if (p)
                {
                        TS1S(0); TS1S(1); TS1S(2); TS1S(3); TS1S(4); TS1S(5); TS1S(6); TS1S(7);
                        p += 8;
                }
                else
                {
                        TS1L(0); TS1L(1); TS1L(2); TS1L(3); TS1L(4); TS1L(5); TS1L(6); TS1L(7);
                }

                TS2(0); TS2(1); TS2(2); TS2(3); TS2(4); TS2(5); TS2(6); TS2(7);
        }
        m_bstart = bstart;
}

template <class B>
size_t PanamaHash<B>::HashMultipleBlocks(const word32 *input, size_t length)
{
        this->Iterate(length / this->BLOCKSIZE, input);
        return length % this->BLOCKSIZE;
}

template <class B>
void PanamaHash<B>::TruncatedFinal(byte *hash, size_t size)
{
        this->ThrowIfInvalidTruncatedSize(size);

        PadLastBlock(this->BLOCKSIZE, 0x01);
        
        HashEndianCorrectedBlock(this->m_data);

        this->Iterate(32);      // pull

        ConditionalByteReverse(B::ToEnum(), this->m_state+9, this->m_state+9, DIGESTSIZE);
        memcpy(hash, this->m_state+9, size);

        this->Restart();                // reinit for next use
}

template <class B>
void PanamaCipherPolicy<B>::CipherSetKey(const NameValuePairs &params, const byte *key, size_t length)
{
        FixedSizeSecBlock<word32, 8> buf;

        this->Reset();
        memcpy(buf, key, 32);
        this->Iterate(1, buf);
        if (length == 64)
                memcpy(buf, key+32, 32);
        else
                memset(buf, 0, 32);
        this->Iterate(1, buf);

        this->Iterate(32);
}

template <class B>
void PanamaCipherPolicy<B>::OperateKeystream(KeystreamOperation operation, byte *output, const byte *input, size_t iterationCount)
{
        this->Iterate(iterationCount, NULL, (word32 *)output, (const word32 *)input);
}

template class Panama<BigEndian>;
template class Panama<LittleEndian>;

template class PanamaHash<BigEndian>;
template class PanamaHash<LittleEndian>;

template class PanamaCipherPolicy<BigEndian>;
template class PanamaCipherPolicy<LittleEndian>;

NAMESPACE_END

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