crypto/secp256k1: Replace CGO impl with external library

crypto/secp256k1/curve.go

@@ -39,10 +39,9 @@ package secp256k1
 import "C"
 
 import (
-	"crypto/elliptic"
 	"math/big"
 
-	"github.com/kaiachain/kaia/common"
+	"github.com/erigontech/secp256k1"
 )
 
 const (
@@ -66,241 +65,9 @@ func readBits(bigint *big.Int, buf []byte) {
 	}
 }
 
-// This code is from https://github.com/ThePiachu/GoBit and implements
-// several Koblitz elliptic curves over prime fields.
-//
-// The curve methods, internally, on Jacobian coordinates. For a given
-// (x, y) position on the curve, the Jacobian coordinates are (x1, y1,
-// z1) where x = x1/z1² and y = y1/z1³. The greatest speedups come
-// when the whole calculation can be performed within the transform
-// (as in ScalarMult and ScalarBaseMult). But even for Add and Double,
-// it's faster to apply and reverse the transform than to operate in
-// affine coordinates.
-
-// A BitCurve represents a Koblitz Curve with a=0.
-// See http://www.hyperelliptic.org/EFD/g1p/auto-shortw.html
-type BitCurve struct {
-	P       *big.Int // the order of the underlying field
-	N       *big.Int // the order of the base point
-	B       *big.Int // the constant of the BitCurve equation
-	Gx, Gy  *big.Int // (x,y) of the base point
-	BitSize int      // the size of the underlying field
-}
-
-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,
-	}
-}
-
-// IsOnCurve returns true if the given (x,y) lies on the BitCurve.
-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
-
-	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
-
-	return x3.Cmp(y2) == 0
-}
-
-// TODO: double check if the function is okay
-// 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) {
-	if z.Sign() == 0 {
-		return new(big.Int), new(big.Int)
-	}
-
-	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)
-	zinvsq.Mul(zinvsq, zinv)
-	yOut = new(big.Int).Mul(y, zinvsq)
-	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) {
-	// 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 {
-		return x2, y2
-	}
-	if x2.Sign() == 0 && y2.Sign() == 0 {
-		return x1, y1
-	}
-	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.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) {
-	// 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)
-	z2z2 := new(big.Int).Mul(z2, z2)
-	z2z2.Mod(z2z2, BitCurve.P)
-
-	u1 := new(big.Int).Mul(x1, z2z2)
-	u1.Mod(u1, BitCurve.P)
-	u2 := new(big.Int).Mul(x2, z1z1)
-	u2.Mod(u2, BitCurve.P)
-	h := new(big.Int).Sub(u2, u1)
-	if h.Sign() == -1 {
-		h.Add(h, BitCurve.P)
-	}
-	i := new(big.Int).Lsh(h, 1)
-	i.Mul(i, i)
-	j := new(big.Int).Mul(h, i)
-
-	s1 := new(big.Int).Mul(y1, z2)
-	s1.Mul(s1, z2z2)
-	s1.Mod(s1, BitCurve.P)
-	s2 := new(big.Int).Mul(y2, z1)
-	s2.Mul(s2, z1z1)
-	s2.Mod(s2, BitCurve.P)
-	r := new(big.Int).Sub(s2, s1)
-	if r.Sign() == -1 {
-		r.Add(r, BitCurve.P)
-	}
-	r.Lsh(r, 1)
-	v := new(big.Int).Mul(u1, i)
-
-	x3 := new(big.Int).Set(r)
-	x3.Mul(x3, x3)
-	x3.Sub(x3, j)
-	x3.Sub(x3, v)
-	x3.Sub(x3, v)
-	x3.Mod(x3, BitCurve.P)
-
-	y3 := new(big.Int).Set(r)
-	v.Sub(v, x3)
-	y3.Mul(y3, v)
-	s1.Mul(s1, j)
-	s1.Lsh(s1, 1)
-	y3.Sub(y3, s1)
-	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.Sub(z3, z2z2)
-	if z3.Sign() == -1 {
-		z3.Add(z3, BitCurve.P)
-	}
-	z3.Mul(z3, h)
-	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) {
-	z1 := new(big.Int).SetInt64(1)
-	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) {
-	// See http://hyperelliptic.org/EFD/g1p/auto-shortw-jacobian-0.html#doubling-dbl-2009-l
-
-	a := new(big.Int).Mul(x, x) // X1²
-	b := new(big.Int).Mul(y, y) // Y1²
-	c := new(big.Int).Mul(b, b) // B²
-
-	d := new(big.Int).Add(x, b) // X1+B
-	d.Mul(d, d)                 //(X1+B)²
-	d.Sub(d, a)                 //(X1+B)²-A
-	d.Sub(d, c)                 //(X1+B)²-A-C
-	d.Mul(d, common.Big2)       // 2*((X1+B)²-A-C)
-
-	e := new(big.Int).Mul(common.Big3, a) // 3*A
-	f := new(big.Int).Mul(e, e)           // E²
-
-	x3 := new(big.Int).Mul(common.Big2, d) // 2*D
-	x3.Sub(f, x3)                          // F-2*D
-	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)
-
-	z3 := new(big.Int).Mul(y, z) // Y1*Z1
-	z3.Mul(common.Big2, z3)      // 3*Y1*Z1
-	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)
-}
-
-// 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
-	ret := make([]byte, 1+2*byteLen)
-	ret[0] = 4 // uncompressed point flag
-	readBits(x, ret[1:1+byteLen])
-	readBits(y, ret[1+byteLen:])
-	return ret
-}
-
-// 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
-	if len(data) != 1+2*byteLen {
-		return
-	}
-	if data[0] != 4 { // uncompressed form
-		return
-	}
-	x = new(big.Int).SetBytes(data[1 : 1+byteLen])
-	y = new(big.Int).SetBytes(data[1+byteLen:])
-	return
-}
-
-var theCurve = new(BitCurve)
-
-func init() {
-	// See SEC 2 section 2.7.1
-	// curve parameters taken from:
-	// http://www.secg.org/sec2-v2.pdf
-	theCurve.P, _ = new(big.Int).SetString("0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFC2F", 0)
-	theCurve.N, _ = new(big.Int).SetString("0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141", 0)
-	theCurve.B, _ = new(big.Int).SetString("0x0000000000000000000000000000000000000000000000000000000000000007", 0)
-	theCurve.Gx, _ = new(big.Int).SetString("0x79BE667EF9DCBBAC55A06295CE870B07029BFCDB2DCE28D959F2815B16F81798", 0)
-	theCurve.Gy, _ = new(big.Int).SetString("0x483ADA7726A3C4655DA4FBFC0E1108A8FD17B448A68554199C47D08FFB10D4B8", 0)
-	theCurve.BitSize = 256
-}
+type BitCurve = secp256k1.BitCurve
 
 // S256 returns a BitCurve which implements secp256k1.
 func S256() *BitCurve {
-	return theCurve
+	return secp256k1.S256()
 }

crypto/secp256k1/doc.go

@@ -19,18 +19,10 @@
 // Modified and improved for the klaytn development.
 
 /*
-Package secp256k1 wraps the bitcoin secp256k1 C library.
+Package secp256k1 wraps the github.com/erigontech/secp256k1 library.
 
-secp256k1 refers to the parameters of the elliptic curve used in Bitcoin's public-key cryptography and is defined in Standards for Efficient Cryptography (SEC)(Certicom Research, http://www.secg.org/sec2-v2.pdf).
-
-Package secp256k1 provides wrapper functions to utilize the library functions in Go.
-
-# Source Files
-
-Each source file has the following contents
-  - secp256.go  : Provides wrapper functions to utilize the secp256k1 library written in C
-  - curve.go    : Implements Koblitz elliptic curves
-  - panic_cb.go : Provides callbacks for converting libsecp256k1 internal faults into recoverable Go panics
-  - schnorr.go  : Implements Schnorr signature algorithm. It is planned to be used in Kaia
+A CGO implementation used to be in this directory. But was deleted and replaced by a simple wrapper to erigontech/secp256k1 package.
+When we imported the erigontech/erigon-lib, the kaiachain/kaia/crypto/secp256k1 and erigontech/secp256k1 caused CGO symbol collision.
+The resolution was using erigontech/secp256k1 only.
 */
 package secp256k1