SM2加签及验证失败

有一段java版本的demo,是完全没有问题的.验证可以通过.

public static String sign(String input, String encodedPrivateKey) throws Exception {
        Signature signature = getInstance();
        signature.initSign(privateKey(encodedPrivateKey));
        signature.update(input.getBytes(StandardCharsets.UTF_8));
        return new String(Base64.getEncoder().encode(signature.sign()), StandardCharsets.UTF_8);
    }

    private static PrivateKey privateKey(String encodedPrivateKey) throws Exception {
        return KeyFactory.getInstance(EC, new BouncyCastleProvider()).generatePrivate(new PKCS8EncodedKeySpec(Base64.getDecoder().decode(encodedPrivateKey)));
    }
 public static boolean verify(String input, String encodedPublicKey, String sign) throws Exception {
        final Signature signature = getInstance();
        signature.initVerify(publicKey(encodedPublicKey));
        signature.update(input.getBytes(StandardCharsets.UTF_8));
        return signature.verify(Base64.getDecoder().decode(sign));
    }

我在C#中,写了一个.可以正常加签,但是加签后验证无法通过.

private void btnSign_Click(object sender, EventArgs e)
        {
            //TxCode +  时间 + 应用id
            String yyyyMMdd = DateTime.Now.ToString("yyyyMMdd");
            String siginBefore = "FCSP" + yyyyMMdd + certificate;

            // 获取sessionKey
            String sessionKeyWithSm4WithBase64 = generateSignKey();
            txtSinger.Text = sessionKeyWithSm4WithBase64;

        }


        public static AsymmetricKeyParameter PrivateASYKeyFromBase64(string encodedPrivateKey)
        {
            byte[] privateKeyBytes = Convert.FromBase64String(encodedPrivateKey);

            // 假设私钥是以PKCS#8格式编码的  
            AsymmetricKeyParameter keyParam = PrivateKeyFactory.CreateKey(privateKeyBytes);

            // 检查私钥是否为椭圆曲线私钥  
            if (!(keyParam is ECPrivateKeyParameters ecPrivateKey))
            {
                throw new ArgumentException("The provided private key is not an EC private key.", nameof(encodedPrivateKey));
            }

            return keyParam;
        }

        //签名
        private string generateSignKey()
        {
            try
            {
                //AsymmetricKeyParameter bcecPrivateKey = PrivateASYKeyFromBase64(privateKey);

                byte[] msg = System.Text.Encoding.UTF8.GetBytes(siginBefore);

                byte[] sig = GmUtil.SignSm3WithSm2(msg,null, PrivateASYKeyFromBase64(privateKey));

                //return Convert.ToBase64String(sig);  //这样不行.

                string utf8String = System.Text.Encoding.UTF8.GetString(sig);

                byte[] bytes = System.Text.Encoding.UTF8.GetBytes(utf8String);

                string base64String = Convert.ToBase64String(bytes);

                return base64String;  //这样也不行.

            }
            catch (Exception ex)
            {
                return "error" + ex.Message;
            }

        }

/**
         * 签名
         * @param msg
         * @param userId
         * @param privateKey
         * @return r||s，直接拼接byte数组的rs
         */
        public static byte[] SignSm3WithSm2(byte[] msg, byte[] userId, AsymmetricKeyParameter privateKey)
        {
            return RsAsn1ToPlainByteArray(SignSm3WithSm2Asn1Rs(msg, userId, privateKey));
        }

        /**
          * @param msg
          * @param userId
          * @param privateKey
          * @return rs in <b>asn1 format</b>
          */
        public static byte[] SignSm3WithSm2Asn1Rs(byte[] msg, byte[] userId, AsymmetricKeyParameter privateKey)
        {
            try
            {
                ISigner signer = SignerUtilities.GetSigner("SM3withSM2");
                //signer.Init(true, new ParametersWithID(privateKey, userId));
                ICipherParameters cp = new ParametersWithRandom(privateKey);
                signer.Init(true, cp);
                signer.BlockUpdate(msg, 0, msg.Length);
                byte[] sig = signer.GenerateSignature();
                return sig;
            }
            catch (Exception e)
            {
                //log.Error("SignSm3WithSm2Asn1Rs error: " + e.Message, e);
                return null;
            }
        }

/**
         * BC的SM3withSM2签名得到的结果的rs是asn1格式的，这个方法转化成直接拼接r||s
         * @param rsDer rs in asn1 format
         * @return sign result in plain byte array
         */
        private static byte[] RsAsn1ToPlainByteArray(byte[] rsDer)
        {
            Asn1Sequence seq = Asn1Sequence.GetInstance(rsDer);
            byte[] r = BigIntToFixexLengthBytes(DerInteger.GetInstance(seq[0]).Value);
            byte[] s = BigIntToFixexLengthBytes(DerInteger.GetInstance(seq[1]).Value);
            byte[] result = new byte[RS_LEN * 2];
            Buffer.BlockCopy(r, 0, result, 0, r.Length);
            Buffer.BlockCopy(s, 0, result, RS_LEN, s.Length);
            return result;
        }

请大神帮忙给看看.