Add secp256k1 wrappers

blindsecp256k1.go

@@ -0,0 +1,50 @@
+package blindsecp256k1
+
+// WARNING: WIP code
+
+import (
+	"crypto/rand"
+	"math/big"
+
+	"github.com/ethereum/go-ethereum/crypto/secp256k1"
+)
+
+type Point struct {
+	X *big.Int
+	Y *big.Int
+}
+
+var (
+	G *Point = &Point{
+		X: secp256k1.S256().Gx,
+		Y: secp256k1.S256().Gy,
+	}
+
+	N *big.Int = secp256k1.S256().N
+)
+
+func (p *Point) Add(q *Point) *Point {
+	x, y := secp256k1.S256().Add(p.X, p.Y, q.X, q.Y)
+	return &Point{
+		X: x,
+		Y: y,
+	}
+}
+
+func (p *Point) Mul(scalar *big.Int) *Point {
+	x, y := secp256k1.S256().ScalarMult(p.X, p.Y, scalar.Bytes())
+	return &Point{
+		X: x,
+		Y: y,
+	}
+}
+
+func newRand() *big.Int {
+	var b [32]byte
+	_, err := rand.Read(b[:])
+	if err != nil {
+		panic(err)
+	}
+	bi := new(big.Int).SetBytes(b[:])
+	return new(big.Int).Mod(bi, N)
+}