Function toBytes [src]
Encode to a Ristretto255 representative.
Prototype
pub fn toBytes(e: Ristretto255) [encoded_length]u8 Parameters
e: Ristretto255 Source
pub fn toBytes(e: Ristretto255) [encoded_length]u8 {
const p = &e.p;
var u1_ = p.z.add(p.y); // Z+Y
const zmy = p.z.sub(p.y); // Z-Y
u1_ = u1_.mul(zmy); // (Z+Y)*(Z-Y)
const u2_ = p.x.mul(p.y); // X*Y
const u1_u2u2 = u2_.sq().mul(u1_); // u1*u2^2
const inv_sqrt = sqrtRatioM1(Fe.one, u1_u2u2);
const den1 = inv_sqrt.root.mul(u1_);
const den2 = inv_sqrt.root.mul(u2_);
const z_inv = den1.mul(den2).mul(p.t); // den1*den2*T
const ix = p.x.mul(Fe.sqrtm1); // X*sqrt(-1)
const iy = p.y.mul(Fe.sqrtm1); // Y*sqrt(-1)
const eden = den1.mul(Fe.edwards25519sqrtamd); // den1/sqrt(a-d)
const t_z_inv = p.t.mul(z_inv); // T*z_inv
const rotate = @intFromBool(t_z_inv.isNegative());
var x = p.x;
var y = p.y;
var den_inv = den2;
x.cMov(iy, rotate);
y.cMov(ix, rotate);
den_inv.cMov(eden, rotate);
const x_z_inv = x.mul(z_inv);
const yneg = y.neg();
y.cMov(yneg, @intFromBool(x_z_inv.isNegative()));
return p.z.sub(y).mul(den_inv).abs().toBytes();
}