/*---------------------------------------------------------------------------*/
void
ecc_add(point_t * P0, point_t * P1, point_t * P2)
{
NN_DIGIT Z0[NUMWORDS];
NN_DIGIT Z1[NUMWORDS];
NN_DIGIT Z2[NUMWORDS];
p_clear(P0);
NN_AssignZero(Z0, NUMWORDS);
NN_AssignZero(Z1, NUMWORDS);
NN_AssignZero(Z2, NUMWORDS);
Z1[0] = 0x01;
Z2[0] = 0x01;
#ifdef ADD_MIX
c_add_mix(P0, Z0, P1, Z1, P2);
#else
ecc_add_proj(P0, Z0, P1, Z1, P2, Z2);
#endif
if(!Z_is_one(Z0)) {
NN_ModInv(Z1, Z0, param.p, NUMWORDS);
NN_ModMultOpt(Z0, Z1, Z1, param.p, param.omega, NUMWORDS);
NN_ModMultOpt(P0->x, P0->x, Z0, param.p, param.omega, NUMWORDS);
NN_ModMultOpt(Z0, Z0, Z1, param.p, param.omega, NUMWORDS);
NN_ModMultOpt(P0->y, P0->y, Z0, param.p, param.omega, NUMWORDS);
}
}
/*
* scalar point multiplication
* P0 = n*basepoint
* pointArray is array of basepoint, pointArray[0] = basepoint, pointArray[1] = 2*basepoint ...
*/
void
ecc_win_mul(point_t * P0, NN_DIGIT * n, point_t * pointArray)
{
int16_t i, tmp;
int8_t j;
NN_DIGIT windex;
NN_DIGIT Z0[NUMWORDS];
NN_DIGIT Z1[NUMWORDS];
#ifndef REPEAT_DOUBLE
int8_t k;
#endif
p_clear(P0);
/* Convert to Jprojective coordinate */
NN_AssignZero(Z0, NUMWORDS);
NN_AssignZero(Z1, NUMWORDS);
Z1[0] = 0x01;
tmp = NN_Digits(n, NUMWORDS);
for(i = tmp - 1; i >= 0; i--) {
for(j = NN_DIGIT_BITS/W_BITS - 1; j >= 0; j--) {
#ifndef REPEAT_DOUBLE
for(k = 0; k < W_BITS; k++) {
ecc_dbl_proj(P0, Z0, P0, Z0);
}
#else
ecc_m_dbl_projective(P0, Z0, W_BITS);
#endif
windex = mask[j] & n[i];
if(windex) {
windex = windex >> (j*W_BITS);
#ifdef ADD_MIX
c_add_mix(P0, Z0, P0, Z0, &(pointArray[windex-1]));
#else
ecc_add_proj(P0, Z0, P0, Z0, &(pointArray[windex-1]), Z1);
#endif
}
}
}
/* Convert back to affine coordinate */
if(!Z_is_one(Z0)) {
NN_ModInv(Z1, Z0, param.p, NUMWORDS);
NN_ModMultOpt(Z0, Z1, Z1, param.p, param.omega, NUMWORDS);
NN_ModMultOpt(P0->x, P0->x, Z0, param.p, param.omega, NUMWORDS);
NN_ModMultOpt(Z0, Z0, Z1, param.p, param.omega, NUMWORDS);
NN_ModMultOpt(P0->y, P0->y, Z0, param.p, param.omega, NUMWORDS);
}
}
/*
* P0 = n * P1
*/
void
ecc_mul ( point_t* P0, point_t* P1, NN_DIGIT* n )
{
int16_t i, tmp;
NN_DIGIT Z0[NUMWORDS];
NN_DIGIT Z1[NUMWORDS];
/* clear point */
p_clear ( P0 );
/* convert to Jprojective coordinate */
NN_AssignZero ( Z0, NUMWORDS );
NN_AssignZero ( Z1, NUMWORDS );
Z1[0] = 0x01;
tmp = NN_Bits ( n, NUMWORDS );
for ( i = tmp-1; i >= 0; i-- )
{
ecc_dbl_proj ( P0, Z0, P0, Z0 );
if ( b_testbit ( n, i ) )
{
#ifdef ADD_MIX
c_add_mix ( P0, Z0, P0, Z0, P1 );
#else
ecc_add_proj ( P0, Z0, P0, Z0, P1, Z1 );
#endif
}
}
/* convert back to affine coordinate */
if ( !Z_is_one ( Z0 ) )
{
NN_ModInv ( Z1, Z0, param.p, NUMWORDS );
NN_ModMultOpt ( Z0, Z1, Z1, param.p, param.omega, NUMWORDS );
NN_ModMultOpt ( P0->x, P0->x, Z0, param.p, param.omega, NUMWORDS );
NN_ModMultOpt ( Z0, Z0, Z1, param.p, param.omega, NUMWORDS );
NN_ModMultOpt ( P0->y, P0->y, Z0, param.p, param.omega, NUMWORDS );
}
}