diff --git a/crypto/secp256k1/curve.go b/crypto/secp256k1/curve.go index 9b26ab292859..85ba885d6f5f 100644 --- a/crypto/secp256k1/curve.go +++ b/crypto/secp256k1/curve.go @@ -79,52 +79,52 @@ type BitCurve struct { BitSize int // the size of the underlying field } -func (BitCurve *BitCurve) Params() *elliptic.CurveParams { +func (bitCurve *BitCurve) Params() *elliptic.CurveParams { return &elliptic.CurveParams{ - P: BitCurve.P, - N: BitCurve.N, - B: BitCurve.B, - Gx: BitCurve.Gx, - Gy: BitCurve.Gy, - BitSize: BitCurve.BitSize, + P: bitCurve.P, + N: bitCurve.N, + B: bitCurve.B, + Gx: bitCurve.Gx, + Gy: bitCurve.Gy, + BitSize: bitCurve.BitSize, } } // IsOnCurve returns true if the given (x,y) lies on the BitCurve. -func (BitCurve *BitCurve) IsOnCurve(x, y *big.Int) bool { +func (bitCurve *BitCurve) IsOnCurve(x, y *big.Int) bool { // y² = x³ + b y2 := new(big.Int).Mul(y, y) //y² - y2.Mod(y2, BitCurve.P) //y²%P + y2.Mod(y2, bitCurve.P) //y²%P x3 := new(big.Int).Mul(x, x) //x² x3.Mul(x3, x) //x³ - x3.Add(x3, BitCurve.B) //x³+B - x3.Mod(x3, BitCurve.P) //(x³+B)%P + x3.Add(x3, bitCurve.B) //x³+B + x3.Mod(x3, bitCurve.P) //(x³+B)%P return x3.Cmp(y2) == 0 } // affineFromJacobian reverses the Jacobian transform. See the comment at the // top of the file. -func (BitCurve *BitCurve) affineFromJacobian(x, y, z *big.Int) (xOut, yOut *big.Int) { +func (bitCurve *BitCurve) affineFromJacobian(x, y, z *big.Int) (xOut, yOut *big.Int) { if z.Sign() == 0 { return new(big.Int), new(big.Int) } - zinv := new(big.Int).ModInverse(z, BitCurve.P) + zinv := new(big.Int).ModInverse(z, bitCurve.P) zinvsq := new(big.Int).Mul(zinv, zinv) xOut = new(big.Int).Mul(x, zinvsq) - xOut.Mod(xOut, BitCurve.P) + xOut.Mod(xOut, bitCurve.P) zinvsq.Mul(zinvsq, zinv) yOut = new(big.Int).Mul(y, zinvsq) - yOut.Mod(yOut, BitCurve.P) + yOut.Mod(yOut, bitCurve.P) return } // Add returns the sum of (x1,y1) and (x2,y2) -func (BitCurve *BitCurve) Add(x1, y1, x2, y2 *big.Int) (*big.Int, *big.Int) { +func (bitCurve *BitCurve) Add(x1, y1, x2, y2 *big.Int) (*big.Int, *big.Int) { // If one point is at infinity, return the other point. // Adding the point at infinity to any point will preserve the other point. if x1.Sign() == 0 && y1.Sign() == 0 { @@ -135,27 +135,27 @@ func (BitCurve *BitCurve) Add(x1, y1, x2, y2 *big.Int) (*big.Int, *big.Int) { } z := new(big.Int).SetInt64(1) if x1.Cmp(x2) == 0 && y1.Cmp(y2) == 0 { - return BitCurve.affineFromJacobian(BitCurve.doubleJacobian(x1, y1, z)) + return bitCurve.affineFromJacobian(bitCurve.doubleJacobian(x1, y1, z)) } - return BitCurve.affineFromJacobian(BitCurve.addJacobian(x1, y1, z, x2, y2, z)) + return bitCurve.affineFromJacobian(bitCurve.addJacobian(x1, y1, z, x2, y2, z)) } // addJacobian takes two points in Jacobian coordinates, (x1, y1, z1) and // (x2, y2, z2) and returns their sum, also in Jacobian form. -func (BitCurve *BitCurve) addJacobian(x1, y1, z1, x2, y2, z2 *big.Int) (*big.Int, *big.Int, *big.Int) { +func (bitCurve *BitCurve) addJacobian(x1, y1, z1, x2, y2, z2 *big.Int) (*big.Int, *big.Int, *big.Int) { // See http://hyperelliptic.org/EFD/g1p/auto-shortw-jacobian-0.html#addition-add-2007-bl z1z1 := new(big.Int).Mul(z1, z1) - z1z1.Mod(z1z1, BitCurve.P) + z1z1.Mod(z1z1, bitCurve.P) z2z2 := new(big.Int).Mul(z2, z2) - z2z2.Mod(z2z2, BitCurve.P) + z2z2.Mod(z2z2, bitCurve.P) u1 := new(big.Int).Mul(x1, z2z2) - u1.Mod(u1, BitCurve.P) + u1.Mod(u1, bitCurve.P) u2 := new(big.Int).Mul(x2, z1z1) - u2.Mod(u2, BitCurve.P) + u2.Mod(u2, bitCurve.P) h := new(big.Int).Sub(u2, u1) if h.Sign() == -1 { - h.Add(h, BitCurve.P) + h.Add(h, bitCurve.P) } i := new(big.Int).Lsh(h, 1) i.Mul(i, i) @@ -163,13 +163,13 @@ func (BitCurve *BitCurve) addJacobian(x1, y1, z1, x2, y2, z2 *big.Int) (*big.Int s1 := new(big.Int).Mul(y1, z2) s1.Mul(s1, z2z2) - s1.Mod(s1, BitCurve.P) + s1.Mod(s1, bitCurve.P) s2 := new(big.Int).Mul(y2, z1) s2.Mul(s2, z1z1) - s2.Mod(s2, BitCurve.P) + s2.Mod(s2, bitCurve.P) r := new(big.Int).Sub(s2, s1) if r.Sign() == -1 { - r.Add(r, BitCurve.P) + r.Add(r, bitCurve.P) } r.Lsh(r, 1) v := new(big.Int).Mul(u1, i) @@ -179,7 +179,7 @@ func (BitCurve *BitCurve) addJacobian(x1, y1, z1, x2, y2, z2 *big.Int) (*big.Int x3.Sub(x3, j) x3.Sub(x3, v) x3.Sub(x3, v) - x3.Mod(x3, BitCurve.P) + x3.Mod(x3, bitCurve.P) y3 := new(big.Int).Set(r) v.Sub(v, x3) @@ -187,33 +187,33 @@ func (BitCurve *BitCurve) addJacobian(x1, y1, z1, x2, y2, z2 *big.Int) (*big.Int s1.Mul(s1, j) s1.Lsh(s1, 1) y3.Sub(y3, s1) - y3.Mod(y3, BitCurve.P) + y3.Mod(y3, bitCurve.P) z3 := new(big.Int).Add(z1, z2) z3.Mul(z3, z3) z3.Sub(z3, z1z1) if z3.Sign() == -1 { - z3.Add(z3, BitCurve.P) + z3.Add(z3, bitCurve.P) } z3.Sub(z3, z2z2) if z3.Sign() == -1 { - z3.Add(z3, BitCurve.P) + z3.Add(z3, bitCurve.P) } z3.Mul(z3, h) - z3.Mod(z3, BitCurve.P) + z3.Mod(z3, bitCurve.P) return x3, y3, z3 } // Double returns 2*(x,y) -func (BitCurve *BitCurve) Double(x1, y1 *big.Int) (*big.Int, *big.Int) { +func (bitCurve *BitCurve) Double(x1, y1 *big.Int) (*big.Int, *big.Int) { z1 := new(big.Int).SetInt64(1) - return BitCurve.affineFromJacobian(BitCurve.doubleJacobian(x1, y1, z1)) + return bitCurve.affineFromJacobian(bitCurve.doubleJacobian(x1, y1, z1)) } // doubleJacobian takes a point in Jacobian coordinates, (x, y, z), and // returns its double, also in Jacobian form. -func (BitCurve *BitCurve) doubleJacobian(x, y, z *big.Int) (*big.Int, *big.Int, *big.Int) { +func (bitCurve *BitCurve) doubleJacobian(x, y, z *big.Int) (*big.Int, *big.Int, *big.Int) { // See http://hyperelliptic.org/EFD/g1p/auto-shortw-jacobian-0.html#doubling-dbl-2009-l a := new(big.Int).Mul(x, x) //X1² @@ -231,30 +231,30 @@ func (BitCurve *BitCurve) doubleJacobian(x, y, z *big.Int) (*big.Int, *big.Int, x3 := new(big.Int).Mul(big.NewInt(2), d) //2*D x3.Sub(f, x3) //F-2*D - x3.Mod(x3, BitCurve.P) + x3.Mod(x3, bitCurve.P) y3 := new(big.Int).Sub(d, x3) //D-X3 y3.Mul(e, y3) //E*(D-X3) y3.Sub(y3, new(big.Int).Mul(big.NewInt(8), c)) //E*(D-X3)-8*C - y3.Mod(y3, BitCurve.P) + y3.Mod(y3, bitCurve.P) z3 := new(big.Int).Mul(y, z) //Y1*Z1 z3.Mul(big.NewInt(2), z3) //3*Y1*Z1 - z3.Mod(z3, BitCurve.P) + z3.Mod(z3, bitCurve.P) return x3, y3, z3 } // ScalarBaseMult returns k*G, where G is the base point of the group and k is // an integer in big-endian form. -func (BitCurve *BitCurve) ScalarBaseMult(k []byte) (*big.Int, *big.Int) { - return BitCurve.ScalarMult(BitCurve.Gx, BitCurve.Gy, k) +func (bitCurve *BitCurve) ScalarBaseMult(k []byte) (*big.Int, *big.Int) { + return bitCurve.ScalarMult(bitCurve.Gx, bitCurve.Gy, k) } // Marshal converts a point into the form specified in section 4.3.6 of ANSI // X9.62. -func (BitCurve *BitCurve) Marshal(x, y *big.Int) []byte { - byteLen := (BitCurve.BitSize + 7) >> 3 +func (bitCurve *BitCurve) Marshal(x, y *big.Int) []byte { + byteLen := (bitCurve.BitSize + 7) >> 3 ret := make([]byte, 1+2*byteLen) ret[0] = 4 // uncompressed point flag readBits(x, ret[1:1+byteLen]) @@ -264,8 +264,8 @@ func (BitCurve *BitCurve) Marshal(x, y *big.Int) []byte { // Unmarshal converts a point, serialised by Marshal, into an x, y pair. On // error, x = nil. -func (BitCurve *BitCurve) Unmarshal(data []byte) (x, y *big.Int) { - byteLen := (BitCurve.BitSize + 7) >> 3 +func (bitCurve *BitCurve) Unmarshal(data []byte) (x, y *big.Int) { + byteLen := (bitCurve.BitSize + 7) >> 3 if len(data) != 1+2*byteLen { return } diff --git a/crypto/secp256k1/scalar_mult_cgo.go b/crypto/secp256k1/scalar_mult_cgo.go index bdf8eeede7df..d11c11faf85b 100644 --- a/crypto/secp256k1/scalar_mult_cgo.go +++ b/crypto/secp256k1/scalar_mult_cgo.go @@ -21,7 +21,7 @@ extern int secp256k1_ext_scalar_mul(const secp256k1_context* ctx, const unsigned */ import "C" -func (BitCurve *BitCurve) ScalarMult(Bx, By *big.Int, scalar []byte) (*big.Int, *big.Int) { +func (bitCurve *BitCurve) ScalarMult(Bx, By *big.Int, scalar []byte) (*big.Int, *big.Int) { // Ensure scalar is exactly 32 bytes. We pad always, even if // scalar is 32 bytes long, to avoid a timing side channel. if len(scalar) > 32 { diff --git a/crypto/secp256k1/scalar_mult_nocgo.go b/crypto/secp256k1/scalar_mult_nocgo.go index 22f53ac6ae65..feb13a8dfd0e 100644 --- a/crypto/secp256k1/scalar_mult_nocgo.go +++ b/crypto/secp256k1/scalar_mult_nocgo.go @@ -9,6 +9,6 @@ package secp256k1 import "math/big" -func (BitCurve *BitCurve) ScalarMult(Bx, By *big.Int, scalar []byte) (*big.Int, *big.Int) { +func (bitCurve *BitCurve) ScalarMult(Bx, By *big.Int, scalar []byte) (*big.Int, *big.Int) { panic("ScalarMult is not available when secp256k1 is built without cgo") }