/// <summary>
/// 签名验证算法
/// 利用签名者的公钥和传过来的r，s来验证签名是否合法
/// </summary>
/// <param name="sm2">sm2对象</param>
/// <param name="ppk">签名者的公钥16进制字符串</param>
/// <param name="Z">签名算法产生的16进制字符串 Z</param>
/// <param name="r">签名算法生成的 R</param>
/// <param name="s">签名算法生成的 S</param>
/// <returns></returns>
public bool Signature_Check(SM2 sm2, string ppk, string Z, string r, string s)
{
ECPoint test_p = null;
//test_p = sm2.userKey;
//MessageBox.Show(ppk);
byte[] key = strToToHexByte(ppk);
test_p = sm2.ecc_curve.DecodePoint(key);
Com.Itrus.Crypto.SM2.SM2Result sm2Ret = new Com.Itrus.Crypto.SM2.SM2Result();//实例化一个SM2Result的对象sm2Ret
SM3Digest sm3 = new SM3Digest();
byte[] z = strToToHexByte(Z);
sm3.BlockUpdate(z, 0, z.Length);
byte[] md = new byte[32];
sm3.DoFinal(md, 0);
sm2Ret.r = new BigInteger(r, 16);
sm2Ret.s = new BigInteger(s, 16);
sm2.Sm2Verify(md, test_p, sm2Ret.r, sm2Ret.s, sm2Ret); //调用Sm2Verify方法，得到R
if (sm2Ret.r.Equals(sm2Ret.R)) //如果r==R
{
return(true); //System.Console.Out.WriteLine("\n签名结果验证通过！r == R\n");
}
else//r!=R
{
return(false);//System.Console.Out.WriteLine("\n签名结果验证失败！r != R\n");
}
}
public static bool VerifySign(string _dataToSign, string _signPack, string _pubKeyX, string _pubKeyY)
{
SM2 sm2 = SM2.Instance;
sm2.cipher_sm = new SM2.Cipher();
string signPack1 = _signPack.Substring(0, 64);
string signPack2 = _signPack.Substring(64, 64);
BigInteger ecc_gx = new BigInteger(_pubKeyX, 16);
BigInteger ecc_gy = new BigInteger(_pubKeyY, 16);
ECFieldElement ecc_gx_fieldElement = sm2.ecc_curve.FromBigInteger(ecc_gx); //选定椭圆曲线上基点 G 的 x 坐标
ECFieldElement ecc_gy_fieldElement = sm2.ecc_curve.FromBigInteger(ecc_gy); //选定椭圆曲线上基点 G 的 y 坐标
ECPoint ecc_point_g = new FpPoint(sm2.ecc_curve, ecc_gx_fieldElement, ecc_gy_fieldElement); //生成基点 G
SM2.SM2Result result = new SM2.SM2Result();
BigInteger gp_br = new BigInteger(signPack1, 16);
BigInteger gp_bs = new BigInteger(signPack2, 16);
result.r = gp_br;
result.s = gp_bs;
sm2.Sm2Verify(HexStringToBytes(_dataToSign), ecc_point_g, gp_br, gp_bs, result);
return(result.R.Equals(result.r));
}