X-Git-Url: http://www.git.cypherpunks.ru/?p=gogost.git;a=blobdiff_plain;f=gost3410%2Fedwards.go;h=9cefec6e6fa013671b74d4905aeb3c8753af536c;hp=43484e061cdabd583ef2b296ae70f4dc521bbd0c;hb=7bed9561c7c09958ad1268b397058431fd3362bc;hpb=220aa87670f1b7ed258374c7ec84a9d9463c7a94

diff --git a/gost3410/edwards.go b/gost3410/edwards.go
index 43484e0..9cefec6 100644
--- a/gost3410/edwards.go
+++ b/gost3410/edwards.go
@@ -31,62 +31,65 @@ func (c *Curve) EdwardsST() (*big.Int, *big.Int) {
 	c.edS.Set(c.E)
 	c.edS.Sub(c.edS, c.D)
 	c.pos(c.edS)
-	c.t.SetUint64(4)
-	c.t.ModInverse(c.t, c.P)
-	c.edS.Mul(c.edS, c.t)
+	var t big.Int
+	t.SetUint64(4)
+	t.ModInverse(&t, c.P)
+	c.edS.Mul(c.edS, &t)
 	c.edS.Mod(c.edS, c.P)
 	c.edT = big.NewInt(0)
 	c.edT.Set(c.E)
 	c.edT.Add(c.edT, c.D)
-	c.t.SetUint64(6)
-	c.t.ModInverse(c.t, c.P)
-	c.edT.Mul(c.edT, c.t)
+	t.SetUint64(6)
+	t.ModInverse(&t, c.P)
+	c.edT.Mul(c.edT, &t)
 	c.edT.Mod(c.edT, c.P)
 	return c.edS, c.edT
 }
 
 // Convert Weierstrass X,Y coordinates to twisted Edwards U,V
-func XY2UV(curve *Curve, x, y *big.Int) (*big.Int, *big.Int) {
-	if !curve.IsEdwards() {
+func XY2UV(c *Curve, x, y *big.Int) (*big.Int, *big.Int) {
+	if !c.IsEdwards() {
 		panic("non twisted Edwards curve")
 	}
-	edS, edT := curve.EdwardsST()
-	curve.t.Sub(x, edT)
-	curve.pos(curve.t)
+	edS, edT := c.EdwardsST()
+	var t big.Int
+	t.Sub(x, edT)
+	c.pos(&t)
 	u := big.NewInt(0)
-	u.ModInverse(y, curve.P)
-	u.Mul(u, curve.t)
-	u.Mod(u, curve.P)
-	v := big.NewInt(0).Set(curve.t)
+	u.ModInverse(y, c.P)
+	u.Mul(u, &t)
+	u.Mod(u, c.P)
+	v := big.NewInt(0).Set(&t)
 	v.Sub(v, edS)
-	curve.pos(v)
-	curve.t.Add(curve.t, edS)
-	curve.t.ModInverse(curve.t, curve.P)
-	v.Mul(v, curve.t)
-	v.Mod(v, curve.P)
+	c.pos(v)
+	t.Add(&t, edS)
+	t.ModInverse(&t, c.P)
+	v.Mul(v, &t)
+	v.Mod(v, c.P)
 	return u, v
 }
 
 // Convert twisted Edwards U,V coordinates to Weierstrass X,Y
-func UV2XY(curve *Curve, u, v *big.Int) (*big.Int, *big.Int) {
-	if !curve.IsEdwards() {
+func UV2XY(c *Curve, u, v *big.Int) (*big.Int, *big.Int) {
+	if !c.IsEdwards() {
 		panic("non twisted Edwards curve")
 	}
-	edS, edT := curve.EdwardsST()
-	curve.tx.Add(bigInt1, v)
-	curve.tx.Mul(curve.tx, edS)
-	curve.tx.Mod(curve.tx, curve.P)
-	curve.ty.Sub(bigInt1, v)
-	curve.pos(curve.ty)
+	edS, edT := c.EdwardsST()
+	var tx, ty big.Int
+	tx.Add(bigInt1, v)
+	tx.Mul(&tx, edS)
+	tx.Mod(&tx, c.P)
+	ty.Sub(bigInt1, v)
+	c.pos(&ty)
 	x := big.NewInt(0)
-	x.ModInverse(curve.ty, curve.P)
-	x.Mul(x, curve.tx)
+	x.ModInverse(&ty, c.P)
+	x.Mul(x, &tx)
 	x.Add(x, edT)
-	x.Mod(x, curve.P)
+	x.Mod(x, c.P)
 	y := big.NewInt(0)
-	y.Mul(u, curve.ty)
-	y.ModInverse(y, curve.P)
-	y.Mul(y, curve.tx)
-	y.Mod(y, curve.P)
+	y.Mul(u, &ty)
+	y.ModInverse(y, c.P)
+	y.Mul(y, &tx)
+	y.Mod(y, c.P)
 	return x, y
 }