More thread-safe gost3410

[gogost.git] / gost3410 / edwards.go

diff --git a/gost3410/edwards.go b/gost3410/edwards.go
index 43484e061cdabd583ef2b296ae70f4dc521bbd0c..9cefec6e6fa013671b74d4905aeb3c8753af536c 100644 (file)
--- 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
 }