/* set (x,y) from two BIGs */
public ECP(BIG ix, BIG iy)
{
x = new FP(ix);
y = new FP(iy);
z = new FP(1);
FP rhs = RHS(x);
if (ROM.CURVETYPE == ROM.MONTGOMERY)
{
if (rhs.jacobi() == 1)
{
INF = false;
}
else
{
inf();
}
}
else
{
FP y2 = new FP(y);
y2.sqr();
if (y2.Equals(rhs))
{
INF = false;
}
else
{
inf();
}
}
}
/* test for O point-at-infinity */
public bool is_infinity()
{
if (ROM.CURVETYPE == ROM.EDWARDS)
{
x.reduce();
y.reduce();
z.reduce();
return(x.iszilch() && y.Equals(z));
}
else
{
return(INF);
}
}
/* set to affine - from (x,y,z) to (x,y) */
public void affine()
{
if (is_infinity())
{
return;
}
FP one = new FP(1);
if (z.Equals(one))
{
return;
}
z.inverse();
if (ROM.CURVETYPE == ROM.WEIERSTRASS)
{
FP z2 = new FP(z);
z2.sqr();
x.mul(z2);
x.reduce();
y.mul(z2);
y.mul(z);
y.reduce();
}
if (ROM.CURVETYPE == ROM.EDWARDS)
{
x.mul(z);
x.reduce();
y.mul(z);
y.reduce();
}
if (ROM.CURVETYPE == ROM.MONTGOMERY)
{
x.mul(z);
x.reduce();
}
z.copy(one);
}
/* Test P == Q */
public bool Equals(ECP Q)
{
if (is_infinity() && Q.is_infinity())
{
return(true);
}
if (is_infinity() || Q.is_infinity())
{
return(false);
}
if (ROM.CURVETYPE == ROM.WEIERSTRASS)
{
FP zs2 = new FP(z);
zs2.sqr();
FP zo2 = new FP(Q.z);
zo2.sqr();
FP zs3 = new FP(zs2);
zs3.mul(z);
FP zo3 = new FP(zo2);
zo3.mul(Q.z);
zs2.mul(Q.x);
zo2.mul(x);
if (!zs2.Equals(zo2))
{
return(false);
}
zs3.mul(Q.y);
zo3.mul(y);
if (!zs3.Equals(zo3))
{
return(false);
}
}
else
{
FP a = new FP(0);
FP b = new FP(0);
a.copy(x);
a.mul(Q.z);
a.reduce();
b.copy(Q.x);
b.mul(z);
b.reduce();
if (!a.Equals(b))
{
return(false);
}
if (ROM.CURVETYPE == ROM.EDWARDS)
{
a.copy(y);
a.mul(Q.z);
a.reduce();
b.copy(Q.y);
b.mul(z);
b.reduce();
if (!a.Equals(b))
{
return(false);
}
}
}
return(true);
}
/* test this=x */
public bool Equals(FP2 x)
{
return(a.Equals(x.a) && b.Equals(x.b));
}
/* test this=1 ? */
public bool IsUnity()
{
FP one = new FP(1);
return(a.Equals(one) && b.IsZilch());
}
/* test this=1 ? */
public bool isunity()
{
FP one = new FP(1);
return(a.Equals(one) && b.iszilch());
}
