/// <summary>
/// 根据指定的公钥来创建新的ECDsa对象，该对象可用于验证签名
/// </summary>
/// <param name="publicKey">公钥</param>
public ECDsa(ECPoint publicKey)
{
this.publicKey = publicKey;
this.curve = publicKey.Curve;
}
/// <summary>
/// 根据指定的私钥和曲线参数来创建新的ECDsa对象，该对象可用于签名
/// </summary>
/// <param name="privateKey">私钥</param>
/// <param name="curve">椭圆曲线参数</param>
public ECDsa(byte[] privateKey, ECCurve curve)
: this(curve.G * privateKey)
{
this.privateKey = privateKey;
}