wake.cpp

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

#include "pch.h"
#include "wake.h"

NAMESPACE_BEGIN(CryptoPP)

void WAKE_TestInstantiations()
{
        WAKE_OFB<>::Encryption x2;
        WAKE_OFB<>::Decryption x4;
}

inline word32 WAKE_Base::M(word32 x, word32 y)
{
        word32 w = x+y;
        return (w>>8) ^ t[w & 0xff];
}

void WAKE_Base::GenKey(word32 k0, word32 k1, word32 k2, word32 k3)
{
        // this code is mostly copied from David Wheeler's paper "A Bulk Data Encryption Algorithm"
        signed int x, z, p;     
        // x and z were declared as "long" in Wheeler's paper, which is a signed type. I don't know if that was intentional, but it's too late to change it now. -- Wei 7/4/2010
        CRYPTOPP_COMPILE_ASSERT(sizeof(x) == 4);
        static int tt[10]= {
                0x726a8f3b,                                                              // table
                0xe69a3b5c,
                0xd3c71fe5,
                0xab3c73d2,
                0x4d3a8eb3,
                0x0396d6e8,
                0x3d4c2f7a,
                0x9ee27cf3, } ;
        t[0] = k0;
        t[1] = k1;
        t[2] = k2;
        t[3] = k3;
        for (p=4 ; p<256 ; p++)
        {
          x=t[p-4]+t[p-1] ;                                        // fill t
          t[p]= (x>>3) ^ tt[x&7] ;
        }

        for (p=0 ; p<23 ; p++)
                t[p]+=t[p+89] ;                   // mix first entries
        x=t[33] ; z=t[59] | 0x01000001 ;
        z=z&0xff7fffff ;
        for (p=0 ; p<256 ; p++) {               //change top byte to
          x=(x&0xff7fffff)+z ;           // a permutation etc
          t[p]=(t[p] & 0x00ffffff) ^ x ; }

        t[256]=t[0] ;
        byte y=byte(x);
        for (p=0 ; p<256 ; p++) {         // further change perm.
          t[p]=t[y=byte(t[p^y]^y)] ;  // and other digits
          t[y]=t[p+1] ;  }
}

template <class B>
void WAKE_Policy<B>::CipherSetKey(const NameValuePairs &params, const byte *key, size_t length)
{
        word32 k0, k1, k2, k3;
        BlockGetAndPut<word32, BigEndian>::Get(key)(r3)(r4)(r5)(r6)(k0)(k1)(k2)(k3);
        GenKey(k0, k1, k2, k3);
}

// OFB
template <class B>
void WAKE_Policy<B>::OperateKeystream(KeystreamOperation operation, byte *output, const byte *input, size_t iterationCount)
{
#define WAKE_OUTPUT(x)\
        while (iterationCount--)\
        {\
                CRYPTOPP_KEYSTREAM_OUTPUT_WORD(x, B::ToEnum(), 0, r6);\
                r3 = M(r3, r6);\
                r4 = M(r4, r3);\
                r5 = M(r5, r4);\
                r6 = M(r6, r5);\
                output += 4;\
                if (!(x & INPUT_NULL))\
                        input += 4;\
        }

        typedef word32 WordType;
        CRYPTOPP_KEYSTREAM_OUTPUT_SWITCH(WAKE_OUTPUT, 0);
}
/*
template <class B>
void WAKE_ROFB_Policy<B>::Iterate(KeystreamOperation operation, byte *output, const byte *input, unsigned int iterationCount)
{
        KeystreamOutput<B> keystreamOperation(operation, output, input);

        while (iterationCount--)
        {
                keystreamOperation(r6);
                r3 = M(r3, r6);
                r4 = M(r4, r3);
                r5 = M(r5, r4);
                r6 = M(r6, r5);
        }
}
*/
template class WAKE_Policy<BigEndian>;
template class WAKE_Policy<LittleEndian>;
//template class WAKE_ROFB_Policy<BigEndian>;
//template class WAKE_ROFB_Policy<LittleEndian>;

NAMESPACE_END