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panama.cpp

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

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

NAMESPACE_BEGIN(CryptoPP)

static const unsigned int STAGES = 32;

Panama::Panama()
        : m_state(17*2 + STAGES*sizeof(Stage))
{
        Reset();
}

void Panama::Reset()
{
        m_bstart = 0;
        memset(m_state, 0, m_state.size*4);
}

void Panama::Iterate(unsigned int 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] = a[i+9]
#define OX(i) z[i] = y[i] ^ a[i+9]
// buffer update
#define US(i) {word32 t=b0[i]; b0[i]=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, 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 <bool H>
unsigned int PanamaHash<H>::HashMultipleBlocks(const word32 *input, unsigned int length)
{
        if (CheckEndianess(HIGHFIRST))
        {
                Iterate(length / BLOCKSIZE, input);
                return length % BLOCKSIZE;
        }
        else
                return IteratedHashBase<word32>::HashMultipleBlocks(input, length);
}

template <bool H>
void PanamaHash<H>::Final(byte *hash)
{
        PadLastBlock(BLOCKSIZE, 0x01);
        CorrectEndianess(data, data, BLOCKSIZE);
        
        vTransform(data);

        Iterate(32);    // pull

        CorrectEndianess(m_state+9, m_state+9, DigestSize());
        memcpy(hash, m_state+9, DigestSize());

        Reinit();               // reinit for next use
}

template <bool H>
PanamaCipher<H>::PanamaCipher(const byte *key, const byte *iv)
        : m_buf(8), m_leftOver(0)
{
        memcpy(m_buf, key, 32);
        CorrectEndianess(m_buf, m_buf, 32);
        Iterate(1, m_buf);
        if (iv)
        {
                memcpy(m_buf, iv, 32);
                CorrectEndianess(m_buf, m_buf, 32);
        }
        else
                memset(m_buf, 0, 32);
        Iterate(1, m_buf);

        Iterate(32);
}

template <bool H>
void PanamaCipher<H>::ProcessString(byte *outString, const byte *inString, unsigned int length)
{
        if (m_leftOver > 0)
        {
                unsigned int len = STDMIN(m_leftOver, length);
                xorbuf(outString, inString, (byte *)(m_buf+m_buf.size)-m_leftOver, len);
                length -= len;
                m_leftOver -= len;
                inString += len;
                outString += len;
        }

        if (CheckEndianess(HIGHFIRST) && IsAligned<word32>(outString))
        {
                if (!IsAligned<word32>(inString))
                {
                        memcpy(outString, inString, length);
                        inString = outString;
                }
                Iterate(length / 32, NULL, (word32 *)outString, (const word32 *)inString);
                inString += length - length % 32;
                outString += length - length % 32;
                length %= 32;
        }

        while (length)
        {
                Iterate(1, NULL, m_buf);
                CorrectEndianess(m_buf, m_buf, 32);
                unsigned int len = STDMIN(32U, length);
                xorbuf(outString, inString, (byte *)m_buf.ptr, len);
                length -= len;
                m_leftOver = 32 - len;
                inString += len;
                outString += len;
        }
}

template class PanamaHash<true>;
template class PanamaHash<false>;

template class PanamaCipher<true>;
template class PanamaCipher<false>;

NAMESPACE_END

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