proper representation of the point at infinity is a single zero byte. if p.isInfinity() == 1 { return append(out[:0], 0) } x, y := new(p256Element), new(p256Element) p.affineFromMont(x, y) out[0] = 4 // Uncompressed form. p256LittleToBig((*[32]byte)(out[1:33]), x) p256LittleToBig((*[32]byte)(out[33:65]), y) return out[:] } // affineFromMont sets (x, y) to the affine coordinates of p, converted out of the // Montgomery domain. func (p *P256Point) affineFromMont(x, y *p256Element) { p256Inverse(y, &p.z)...