elliptic

type Curve interface {
	// Params returns the parameters for the curve.
	Params() *CurveParams

	// IsOnCurve reports whether the given (x,y) lies on the curve.
	//
	// Deprecated: this is a low-level unsafe API. For ECDH, use the crypto/ecdh
	// package. The NewPublicKey methods of NIST curves in crypto/ecdh accept
	// the same encoding as the Unmarshal function, and perform on-curve checks.
	IsOnCurve(x, y *big.Int) bool

	// Add returns the sum of (x1,y1) and (x2,y2).
	//
	// Deprecated: this is a low-level unsafe API.
	Add(x1, y1, x2, y2 *big.Int) (x, y *big.Int)

	// Double returns 2*(x,y).
	//
	// Deprecated: this is a low-level unsafe API.
	Double(x1, y1 *big.Int) (x, y *big.Int)

	// ScalarMult returns k*(x,y) where k is an integer in big-endian form.
	//
	// Deprecated: this is a low-level unsafe API. For ECDH, use the crypto/ecdh
	// package. Most uses of ScalarMult can be replaced by a call to the ECDH
	// methods of NIST curves in crypto/ecdh.
	ScalarMult(x1, y1 *big.Int, k []byte) (x, y *big.Int)

	// ScalarBaseMult returns k*G, where G is the base point of the group
	// and k is an integer in big-endian form.
	//
	// Deprecated: this is a low-level unsafe API. For ECDH, use the crypto/ecdh
	// package. Most uses of ScalarBaseMult can be replaced by a call to the
	// PrivateKey.PublicKey method in crypto/ecdh.
	ScalarBaseMult(k []byte) (x, y *big.Int)
}

type CurveParams 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 curve equation
	Gx, Gy  *big.Int // (x,y) of the base point
	BitSize int      // the size of the underlying field
	Name    string   // the canonical name of the curve
}