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internal/group: make conversion APIs caller-allocated

This commit is contained in:
Filippo Valsorda 2019-01-26 21:08:22 -05:00 committed by George Tankersley
parent 79589420d8
commit 380ecb67b1
1 changed files with 2 additions and 10 deletions
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12
internal/group/ge.go
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@ -62,14 +62,10 @@ func (v *ExtendedGroupElement) ToAffine() (*big.Int, *big.Int) {
}
// Per HWCD, it is safe to move from extended to projective by simply ignoring T.
func (v *ExtendedGroupElement) ToProjective() *ProjectiveGroupElement {
var p ProjectiveGroupElement
func (v *ExtendedGroupElement) ToProjective(p *ProjectiveGroupElement) {
p.X.Set(&v.X)
p.Y.Set(&v.Y)
p.Z.Set(&v.Z)
return &p
}
func (v *ExtendedGroupElement) Zero() *ExtendedGroupElement {
@ -193,15 +189,11 @@ func (v *ProjectiveGroupElement) ToAffine() (*big.Int, *big.Int) {
// HWCD Section 3: "Given (X : Y : Z) in [projective coordinates] passing to
// [extended coordinates, (X : Y : T : Z)] can be performed in 3M+1S by computing
// (XZ, YZ, XY, Z^2)"
func (v *ProjectiveGroupElement) ToExtended() *ExtendedGroupElement {
var r ExtendedGroupElement
func (v *ProjectiveGroupElement) ToExtended(r *ExtendedGroupElement) {
r.X.Mul(&v.X, &v.Z)
r.Y.Mul(&v.Y, &v.Z)
r.T.Mul(&v.X, &v.Y)
r.Z.Square(&v.Z)
return &r
}
func (v *ProjectiveGroupElement) Zero() *ProjectiveGroupElement {