go.cypherpunks.ru namespace usage

[gogost.git] / src / cypherpunks.ru / gogost / gost3410 / edwards.go

diff --git a/src/cypherpunks.ru/gogost/gost3410/edwards.go b/src/cypherpunks.ru/gogost/gost3410/edwards.go
deleted file mode 100644 (file)
index 10b1c6a..0000000
--- a/src/cypherpunks.ru/gogost/gost3410/edwards.go
+++ /dev/null
@@ -1,92 +0,0 @@
-// GoGOST -- Pure Go GOST cryptographic functions library
-// Copyright (C) 2015-2019 Sergey Matveev <stargrave@stargrave.org>
-//
-// This program is free software: you can redistribute it and/or modify
-// it under the terms of the GNU General Public License as published by
-// the Free Software Foundation, version 3 of the License.
-//
-// This program is distributed in the hope that it will be useful,
-// but WITHOUT ANY WARRANTY; without even the implied warranty of
-// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-// GNU General Public License for more details.
-//
-// You should have received a copy of the GNU General Public License
-// along with this program.  If not, see <http://www.gnu.org/licenses/>.
-
-package gost3410
-
-import (
-       "math/big"
-)
-
-func (c *Curve) IsEdwards() bool {
-       return c.E != nil
-}
-
-func (c *Curve) EdwardsST() (*big.Int, *big.Int) {
-       if c.edS != nil {
-               return c.edS, c.edT
-       }
-       c.edS = big.NewInt(0)
-       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)
-       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)
-       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() {
-               panic("non twisted Edwards curve")
-       }
-       edS, edT := curve.EdwardsST()
-       curve.t.Sub(x, edT)
-       curve.pos(curve.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)
-       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)
-       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() {
-               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)
-       x := big.NewInt(0)
-       x.ModInverse(curve.ty, curve.P)
-       x.Mul(x, curve.tx)
-       x.Add(x, edT)
-       x.Mod(x, curve.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)
-       return x, y
-}