X-Git-Url: http://www.git.cypherpunks.ru/?a=blobdiff_plain;f=src%2Fcypherpunks.ru%2Fgogost%2Fgost3410%2Fcurve.go;h=b25131636f3605fdea75c2adeef6dfc3a88219ea;hb=64f9decbd53306c271661bf70a232963f75365a3;hp=d253d8eea61adea237e7f7dfb63ad249cdd80c4b;hpb=014be6ab0719643d1e2996a360ab0619124b7e0e;p=gogost.git

diff --git a/src/cypherpunks.ru/gogost/gost3410/curve.go b/src/cypherpunks.ru/gogost/gost3410/curve.go
index d253d8e..b251316 100644
--- a/src/cypherpunks.ru/gogost/gost3410/curve.go
+++ b/src/cypherpunks.ru/gogost/gost3410/curve.go
@@ -1,5 +1,5 @@
 // GoGOST -- Pure Go GOST cryptographic functions library
-// Copyright (C) 2015-2017 Sergey Matveev <stargrave@stargrave.org>
+// 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
@@ -29,14 +29,16 @@ var (
 )
 
 type Curve struct {
-	P *big.Int
-	Q *big.Int
+	P *big.Int // Characteristic of the underlying prime field
+	Q *big.Int // Elliptic curve subgroup order
+
+	// Equation coefficients of the elliptic curve in canonical form
 	A *big.Int
 	B *big.Int
 
 	// Basic point X and Y coordinates
-	Bx *big.Int
-	By *big.Int
+	X *big.Int
+	Y *big.Int
 
 	// Temporary variable for the add method
 	t  *big.Int
@@ -44,33 +46,32 @@ type Curve struct {
 	ty *big.Int
 }
 
-func NewCurve(p, q, a, b, bx, by []byte) (*Curve, error) {
+func NewCurve(p, q, a, b, x, y *big.Int) (*Curve, error) {
 	c := Curve{
-		P:  bytes2big(p[:]),
-		Q:  bytes2big(q[:]),
-		A:  bytes2big(a[:]),
-		B:  bytes2big(b[:]),
-		Bx: bytes2big(bx[:]),
-		By: bytes2big(by[:]),
+		P:  p,
+		Q:  q,
+		A:  a,
+		B:  b,
+		X:  x,
+		Y:  y,
 		t:  big.NewInt(0),
 		tx: big.NewInt(0),
 		ty: big.NewInt(0),
 	}
 	r1 := big.NewInt(0)
 	r2 := big.NewInt(0)
-	r1.Mul(c.By, c.By)
+	r1.Mul(c.Y, c.Y)
 	r1.Mod(r1, c.P)
-	r2.Mul(c.Bx, c.Bx)
+	r2.Mul(c.X, c.X)
 	r2.Add(r2, c.A)
-	r2.Mul(r2, c.Bx)
+	r2.Mul(r2, c.X)
 	r2.Add(r2, c.B)
 	r2.Mod(r2, c.P)
-	if r2.Cmp(big.NewInt(0)) == -1 {
-		r2.Add(r2, c.P)
-	}
+	c.pos(r2)
 	if r1.Cmp(r2) != 0 {
 		return nil, errors.New("Invalid curve parameters")
 	}
+	}
 	return &c, nil
 }