OA2023/OASystem/PaymentSystem.Api/OAMethodLib/sm3withsm2.cs

namespace OASystem.API.CMBPayBusiness
{
    /**
     * need lib:
     * BouncyCastle.Crypto.dll（http://www.bouncycastle.org/csharp/index.html）（这段代码写的时候用的bccrypto-csharp-1.8.8，最低支持版本和最高支持版本自己研究）
     * log4net.dll（http://logging.apache.org/log4net/）（仅为了输出日志用，不用的话可自行改换其他方式输出异常信息）
     *
     * ref:
     * https://tools.ietf.org/html/draft-shen-sm2-ecdsa-02
     * http://gmssl.org/docs/oid.html
     * http://www.jonllen.com/jonllen/work/164.aspx
     *
     * 用BC的注意点：
     * 这个版本的BC对SM3withSM2的结果为asn1格式的r和s，如果需要直接拼接的r||s需要自己转换。下面rsAsn1ToPlainByteArray、rsPlainByteArrayToAsn1就在干这事。
     * 这个版本的BC对SM2的结果为C1||C2||C3，据说为旧标准，新标准为C1||C3||C2，用新标准的需要自己转换。下面（被注释掉的）changeC1C2C3ToC1C3C2、changeC1C3C2ToC1C2C3就在干这事。java版的高版本有加上C1C3C2，csharp版没准以后也会加，但目前还没有，java版的目前可以初始化时“ SM2Engine sm2Engine = new SM2Engine(SM2Engine.Mode.C1C3C2);”。
     * 
     */
    public class GmUtil
    {



        private static X9ECParameters x9ECParameters = GMNamedCurves.GetByName("sm2p256v1");
        private static ECDomainParameters ecDomainParameters = new ECDomainParameters(x9ECParameters.Curve, x9ECParameters.G, x9ECParameters.N);
        //国密标准公钥头(固定值)
        public const string SM2_KEY_TITLE = "3059301306072a8648ce3d020106082a811ccf5501822d03420004";
        //国密局推荐 ID(固定值)
        public const string SM_USER_ID = "1234567812345678";
        //国密私钥
        public const string SM_PRIVATE_KEY = "D5F2AFA24E6BA9071B54A8C9AD735F9A1DE9C4657FA386C09B592694BC118B38";
        //国密公钥 base64
        public const string SM_PUBLIC_KEY = "MFkwEwYHKoZIzj0CAQYIKoEcz1UBgi0DQgAE6Q+fktsnY9OFP+LpSR5Udbxf5zHCFO0PmOKlFNTxDIGl8jsPbbB/9ET23NV+acSz4FEkzD74sW2iiNVHRLiKHg==";

        /**
         *
         * @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));
        }



        /**
         * 将BC SM2 RAW签名值转化为ASN1格式签名值
         * @param bcCipTxt
         * @return
         * @throws Exception
         */
        private static byte[] signRawToAsn1(byte[] bcCipTxt)
        {

            byte[] netSignCipTxt = new byte[73];

            byte[] signR = new byte[32];
            byte[] signS = new byte[32];

            Buffer.BlockCopy(bcCipTxt, 0, signR, 0, 32);
            Buffer.BlockCopy(bcCipTxt, 32, signS, 0, 32);

            //signR补位
            int wPos = 4;
            netSignCipTxt[0] = 0x30;
            netSignCipTxt[2] = 0x02;
            if ((signR[0] & 0xFF) >= 128)
            {
                netSignCipTxt[wPos - 1] = 0x21;
                netSignCipTxt[wPos] = 0x00;
                wPos += 1;
            }
            else
            {
                netSignCipTxt[wPos - 1] = 0x20;
            }
            Buffer.BlockCopy(signR, 0, netSignCipTxt, wPos, 32);
            wPos += 32;

            //signS补位
            netSignCipTxt[wPos] = 0x02;
            wPos += 1;
            if ((signS[0] & 0xFF) >= 128)
            {
                netSignCipTxt[wPos] = 0x21;
                wPos += 1;
                netSignCipTxt[wPos] = 0x00;
                wPos += 1;
            }
            else
            {
                netSignCipTxt[wPos] = 0x20;
                wPos += 1;
            }
            Buffer.BlockCopy(signS, 0, netSignCipTxt, wPos, 32);
            wPos += 32;

            if (70 == wPos)
            {
                netSignCipTxt[1] = 0x44;
            }
            else if (71 == wPos)
            {
                netSignCipTxt[1] = 0x45;
            }
            else if (72 == wPos)
            {
                netSignCipTxt[1] = 0x46;
            }
            else
            {
                throw new Exception("signRawToAsn1 Error!");
            }

            byte[] resultBytes = new byte[wPos];
            Buffer.BlockCopy(netSignCipTxt, 0, resultBytes, 0, wPos);

            return resultBytes;
        }

        /**
         * 将ASN1格式签名值转化为BC SM2 RAW 签名值
         *
         * @param  signature Asn1格式签名值
         * @return byte[] Raw签名值
         */
        private static byte[] signAsn12Raw(byte[] signature)
        {

            byte[] resultBytes = new byte[64];

            //截取signR
            int wPos = 3;
            if ((signature[wPos] & 0xFF) == 32)
            {
                wPos += 1;
            }
            else if ((signature[wPos] & 0xFF) == 33)
            {
                wPos += 2;
            }
            else
            {
                throw new Exception("signR length Error!");
            }
            Buffer.BlockCopy(signature, wPos, resultBytes, 0, 32);
            wPos += 32;

            //截取signS
            wPos += 1;
            if ((signature[wPos] & 0xFF) == 32)
            {
                wPos += 1;
            }
            else if ((signature[wPos] & 0xFF) == 33)
            {
                wPos += 2;
            }
            else
            {
                throw new Exception("signS length Error!");
            }
            Buffer.BlockCopy(signature, wPos, resultBytes, 32, 32);



            return resultBytes;
        }

        /**
          * @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));
                signer.BlockUpdate(msg, 0, msg.Length);
                byte[] sig = signer.GenerateSignature();
                return sig;
            }
            catch (Exception e)
            {
                ////log.Error("SignSm3WithSm2Asn1Rs error: " + e.Message, e);
                return null;
            }
        }

        /**
        *
        * @param msg
        * @param userId
        * @param rs r||s，直接拼接byte数组的rs
        * @param publicKey
        * @return
        */
        public static bool VerifySm3WithSm2(byte[] msg, byte[] userId, byte[] rs, AsymmetricKeyParameter publicKey)
        {
            if (rs == null || msg == null || userId == null) return false;
            if (rs.Length != RS_LEN * 2) return false;
            return VerifySm3WithSm2Asn1Rs(msg, userId, RsPlainByteArrayToAsn1(rs), publicKey);
        }

        /**
         *
         * @param msg
         * @param userId
         * @param rs in <b>asn1 format</b>
         * @param publicKey
         * @return
         */

        public static bool VerifySm3WithSm2Asn1Rs(byte[] msg, byte[] userId, byte[] sign, AsymmetricKeyParameter publicKey)
        {
            try
            {
                ISigner signer = SignerUtilities.GetSigner("SM3withSM2");
                signer.Init(false, new ParametersWithID(publicKey, userId));
                signer.BlockUpdate(msg, 0, msg.Length);
                return signer.VerifySignature(sign);
            }
            catch (Exception e)
            {
                ////log.Error("VerifySm3WithSm2Asn1Rs error: " + e.Message, e);
                return false;
            }
        }

        /**
         * bc加解密使用旧标c1||c2||c3，此方法在加密后调用，将结果转化为c1||c3||c2
         * @param c1c2c3
         * @return
         */
        private static byte[] ChangeC1C2C3ToC1C3C2(byte[] c1c2c3)
        {
            int c1Len = (x9ECParameters.Curve.FieldSize + 7) / 8 * 2 + 1; //sm2p256v1的这个固定65。可看GMNamedCurves、ECCurve代码。
            const int c3Len = 32; //new SM3Digest().getDigestSize();
            byte[] result = new byte[c1c2c3.Length];
            Buffer.BlockCopy(c1c2c3, 0, result, 0, c1Len); //c1
            Buffer.BlockCopy(c1c2c3, c1c2c3.Length - c3Len, result, c1Len, c3Len); //c3
            Buffer.BlockCopy(c1c2c3, c1Len, result, c1Len + c3Len, c1c2c3.Length - c1Len - c3Len); //c2
            return result;
        }


        /**
         * bc加解密使用旧标c1||c3||c2，此方法在解密前调用，将密文转化为c1||c2||c3再去解密
         * @param c1c3c2
         * @return
         */
        private static byte[] ChangeC1C3C2ToC1C2C3(byte[] c1c3c2)
        {
            int c1Len = (x9ECParameters.Curve.FieldSize + 7) / 8 * 2 + 1; //sm2p256v1的这个固定65。可看GMNamedCurves、ECCurve代码。
            const int c3Len = 32; //new SM3Digest().GetDigestSize();
            byte[] result = new byte[c1c3c2.Length];
            Buffer.BlockCopy(c1c3c2, 0, result, 0, c1Len); //c1: 0->65
            Buffer.BlockCopy(c1c3c2, c1Len + c3Len, result, c1Len, c1c3c2.Length - c1Len - c3Len); //c2
            Buffer.BlockCopy(c1c3c2, c1Len, result, c1c3c2.Length - c3Len, c3Len); //c3
            return result;
        }

        /**
         * c1||c3||c2
         * @param data
         * @param key
         * @return
         */
        public static byte[] Sm2Decrypt(byte[] data, AsymmetricKeyParameter key)
        {
            return Sm2DecryptOld(ChangeC1C3C2ToC1C2C3(data), key);
        }

        /**
         * c1||c3||c2
         * @param data
         * @param key
         * @return
         */

        public static byte[] Sm2Encrypt(byte[] data, AsymmetricKeyParameter key)
        {
            return ChangeC1C2C3ToC1C3C2(Sm2EncryptOld(data, key));
        }

        /**
         * c1||c2||c3
         * @param data
         * @param key
         * @return
         */
        public static byte[] Sm2EncryptOld(byte[] data, AsymmetricKeyParameter pubkey)
        {
            try
            {
                SM2Engine sm2Engine = new SM2Engine();
                sm2Engine.Init(true, new ParametersWithRandom(pubkey, new SecureRandom()));
                return sm2Engine.ProcessBlock(data, 0, data.Length);
            }
            catch (Exception e)
            {
                ////log.Error("Sm2EncryptOld error: " + e.Message, e);
                return null;
            }
        }

        /**
         * c1||c2||c3
         * @param data
         * @param key
         * @return
         */
        public static byte[] Sm2DecryptOld(byte[] data, AsymmetricKeyParameter key)
        {
            try
            {
                SM2Engine sm2Engine = new SM2Engine();
                sm2Engine.Init(false, key);
                return sm2Engine.ProcessBlock(data, 0, data.Length);
            }
            catch (Exception e)
            {
                ////log.Error("Sm2DecryptOld error: " + e.Message, e);
                return null;
            }
        }

        /**
         * @param bytes
         * @return
         */
        public static byte[] Sm3(byte[] bytes)
        {
            try
            {
                SM3Digest digest = new SM3Digest();
                digest.BlockUpdate(bytes, 0, bytes.Length);
                byte[] result = DigestUtilities.DoFinal(digest);
                return result;
            }
            catch (Exception e)
            {
                //log.Error("Sm3 error: " + e.Message, e);
                return null;
            }
        }

        private const int RS_LEN = 32;

        private static byte[] BigIntToFixexLengthBytes(BigInteger rOrS)
        {
            // for sm2p256v1, n is 00fffffffeffffffffffffffffffffffff7203df6b21c6052b53bbf40939d54123,
            // r and s are the result of mod n, so they should be less than n and have length<=32
            byte[] rs = rOrS.ToByteArray();
            if (rs.Length == RS_LEN) return rs;
            else if (rs.Length == RS_LEN + 1 && rs[0] == 0) return Arrays.CopyOfRange(rs, 1, RS_LEN + 1);
            else if (rs.Length < RS_LEN)
            {
                byte[] result = new byte[RS_LEN];
                Arrays.Fill(result, 0);
                Buffer.BlockCopy(rs, 0, result, RS_LEN - rs.Length, rs.Length);
                return result;
            }
            else
            {
                throw new ArgumentException("err rs: " + Hex.ToHexString(rs));
            }
        }

        /**
         * 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;
        }

        /**
         * BC的SM3withSM2验签需要的rs是asn1格式的，这个方法将直接拼接r||s的字节数组转化成asn1格式
         * @param sign in plain byte array
         * @return rs result in asn1 format
         */
        private static byte[] RsPlainByteArrayToAsn1(byte[] sign)
        {
            if (sign.Length != RS_LEN * 2) throw new ArgumentException("err rs. ");
            BigInteger r = new BigInteger(1, Arrays.CopyOfRange(sign, 0, RS_LEN));
            BigInteger s = new BigInteger(1, Arrays.CopyOfRange(sign, RS_LEN, RS_LEN * 2));
            Asn1EncodableVector v = new Asn1EncodableVector();
            v.Add(new DerInteger(r));
            v.Add(new DerInteger(s));
            try
            {
                return new DerSequence(v).GetEncoded("DER");
            }
            catch (IOException e)
            {
                //log.Error("RsPlainByteArrayToAsn1 error: " + e.Message, e);
                return null;
            }
        }

        public static AsymmetricCipherKeyPair GenerateKeyPair()
        {
            try
            {
                ECKeyPairGenerator kpGen = new ECKeyPairGenerator();
                kpGen.Init(new ECKeyGenerationParameters(ecDomainParameters, new SecureRandom()));
                return kpGen.GenerateKeyPair();
            }
            catch (Exception e)
            {
                //log.Error("generateKeyPair error: " + e.Message, e);
                return null;
            }
        }

        public static ECPrivateKeyParameters GetPrivatekeyFromD(BigInteger d)
        {
            return new ECPrivateKeyParameters(d, ecDomainParameters);
        }

        public static ECPublicKeyParameters GetPublickeyFromXY(BigInteger x, BigInteger y)
        {
            return new ECPublicKeyParameters(x9ECParameters.Curve.CreatePoint(x, y), ecDomainParameters);
        }

        public static AsymmetricKeyParameter GetPublickeyFromX509File(FileInfo file)
        {

            FileStream fileStream = null;
            try
            {
                //file.DirectoryName + "\\" + file.Name
                fileStream = new FileStream(file.FullName, FileMode.Open, FileAccess.Read);
                X509Certificate certificate = new X509CertificateParser().ReadCertificate(fileStream);
                return certificate.GetPublicKey();
            }
            catch (Exception e)
            {
                //log.Error(file.Name + "读取失败，异常：" + e);
            }
            finally
            {
                if (fileStream != null)
                    fileStream.Close();
            }
            return null;
        }

        public class Sm2Cert
        {
            public AsymmetricKeyParameter privateKey;
            public AsymmetricKeyParameter publicKey;
            public string certId;
        }

        private static byte[] ToByteArray(int i)
        {
            byte[] byteArray = new byte[4];
            byteArray[0] = (byte)(i >> 24);
            byteArray[1] = (byte)((i & 0xFFFFFF) >> 16);
            byteArray[2] = (byte)((i & 0xFFFF) >> 8);
            byteArray[3] = (byte)(i & 0xFF);
            return byteArray;
        }

        /**
         * 字节数组拼接
         *
         * @param params
         * @return
         */
        private static byte[] Join(params byte[][] byteArrays)
        {
            List<byte> byteSource = new List<byte>();
            for (int i = 0; i < byteArrays.Length; i++)
            {
                byteSource.AddRange(byteArrays[i]);
            }
            byte[] data = byteSource.ToArray();
            return data;
        }

        /**
         * 密钥派生函数
         *
         * @param Z
         * @param klen
         *            生成klen字节数长度的密钥
         * @return
         */
        private static byte[] KDF(byte[] Z, int klen)
        {
            int ct = 1;
            int end = (int)Math.Ceiling(klen * 1.0 / 32);
            List<byte> byteSource = new List<byte>();
            try
            {
                for (int i = 1; i < end; i++)
                {
                    byteSource.AddRange(Sm3(Join(Z, ToByteArray(ct))));
                    ct++;
                }
                byte[] last = Sm3(Join(Z, ToByteArray(ct)));
                if (klen % 32 == 0)
                {
                    byteSource.AddRange(last);
                }
                else
                    byteSource.AddRange(Arrays.CopyOfRange(last, 0, klen % 32));
                return byteSource.ToArray();
            }
            catch (Exception e)
            {
                //log.Error("KDF error: " + e.Message, e);
            }
            return null;
        }

        public static byte[] Sm4DecryptCBC(byte[] keyBytes, byte[] cipher, byte[] iv, string algo)
        {
            if (keyBytes.Length != 16) throw new ArgumentException("err key length");
            if (cipher.Length % 16 != 0) throw new ArgumentException("err data length");

            try
            {
                KeyParameter key = ParameterUtilities.CreateKeyParameter("SM4", keyBytes);
                IBufferedCipher c = CipherUtilities.GetCipher(algo);
                if (iv == null) iv = ZeroIv(algo);
                c.Init(false, new ParametersWithIV(key, iv));
                return c.DoFinal(cipher);
            }
            catch (Exception e)
            {
                //log.Error("Sm4DecryptCBC error: " + e.Message, e);
                return null;
            }
        }


        public static byte[] Sm4EncryptCBC(byte[] keyBytes, byte[] plain, byte[] iv, string algo)
        {
            if (keyBytes.Length != 16) throw new ArgumentException("err key length");
            if (plain.Length % 16 != 0) throw new ArgumentException("err data length");

            try
            {
                KeyParameter key = ParameterUtilities.CreateKeyParameter("SM4", keyBytes);
                IBufferedCipher c = CipherUtilities.GetCipher(algo);
                if (iv == null) iv = ZeroIv(algo);
                c.Init(true, new ParametersWithIV(key, iv));
                return c.DoFinal(plain);
            }
            catch (Exception e)
            {
                //log.Error("Sm4EncryptCBC error: " + e.Message, e);
                return null;
            }
        }


        public static byte[] Sm4EncryptECB(byte[] keyBytes, byte[] plain, string algo)
        {
            if (keyBytes.Length != 16) throw new ArgumentException("err key length");
            if (plain.Length % 16 != 0) throw new ArgumentException("err data length");

            try
            {
                KeyParameter key = ParameterUtilities.CreateKeyParameter("SM4", keyBytes);
                IBufferedCipher c = CipherUtilities.GetCipher(algo);
                c.Init(true, key);
                return c.DoFinal(plain);
            }
            catch (Exception e)
            {
                //log.Error("Sm4EncryptECB error: " + e.Message, e);
                return null;
            }
        }

        public static byte[] Sm4DecryptECB(byte[] keyBytes, byte[] cipher, string algo)
        {
            if (keyBytes.Length != 16) throw new ArgumentException("err key length");
            if (cipher.Length % 16 != 0) throw new ArgumentException("err data length");

            try
            {
                KeyParameter key = ParameterUtilities.CreateKeyParameter("SM4", keyBytes);
                IBufferedCipher c = CipherUtilities.GetCipher(algo);
                c.Init(false, key);
                return c.DoFinal(cipher);
            }
            catch (Exception e)
            {
                //log.Error("Sm4DecryptECB error: " + e.Message, e);
                return null;
            }
        }

        public const string SM4_ECB_NOPADDING = "SM4/ECB/NoPadding";
        public const string SM4_CBC_NOPADDING = "SM4/CBC/NoPadding";
        public const string SM4_CBC_PKCS7PADDING = "SM4/CBC/PKCS7Padding";

        /**
         * cfca官网CSP沙箱导出的sm2文件
         * @param pem 二进制原文
         * @param pwd 密码
         * @return
         */
        public static Sm2Cert readSm2File(byte[] pem, string pwd)
        {

            Sm2Cert sm2Cert = new Sm2Cert();
            try
            {
                Asn1Sequence asn1Sequence = (Asn1Sequence)Asn1Object.FromByteArray(pem);
                //	    	ASN1Integer asn1Integer = (ASN1Integer) asn1Sequence.getObjectAt(0); //version=1
                Asn1Sequence priSeq = (Asn1Sequence)asn1Sequence[1];//private key
                Asn1Sequence pubSeq = (Asn1Sequence)asn1Sequence[2];//public key and x509 cert

                //	    	ASN1ObjectIdentifier sm2DataOid = (ASN1ObjectIdentifier) priSeq.getObjectAt(0);
                //	    	ASN1ObjectIdentifier sm4AlgOid = (ASN1ObjectIdentifier) priSeq.getObjectAt(1);
                Asn1OctetString priKeyAsn1 = (Asn1OctetString)priSeq[2];
                byte[] key = KDF(Encoding.UTF8.GetBytes(pwd), 32);
                byte[] priKeyD = Sm4DecryptCBC(Arrays.CopyOfRange(key, 16, 32),
                        priKeyAsn1.GetOctets(),
                        Arrays.CopyOfRange(key, 0, 16), SM4_CBC_PKCS7PADDING);
                sm2Cert.privateKey = GetPrivatekeyFromD(new BigInteger(1, priKeyD));
                //	    	//log.Info(Hex.toHexString(priKeyD));

                //	    	ASN1ObjectIdentifier sm2DataOidPub = (ASN1ObjectIdentifier) pubSeq.getObjectAt(0);
                Asn1OctetString pubKeyX509 = (Asn1OctetString)pubSeq[1];
                X509Certificate x509 = new X509CertificateParser().ReadCertificate(pubKeyX509.GetOctets());
                sm2Cert.publicKey = x509.GetPublicKey();
                sm2Cert.certId = x509.SerialNumber.ToString(10); //这里转10进账，有啥其他进制要求的自己改改
                return sm2Cert;
            }
            catch (Exception e)
            {
                //log.Error("readSm2File error: " + e.Message, e);
                return null;
            }
        }

        /**
         *
         * @param cert
         * @return
         */
        public static Sm2Cert ReadSm2X509Cert(byte[] cert)
        {
            Sm2Cert sm2Cert = new Sm2Cert();
            try
            {

                X509Certificate x509 = new X509CertificateParser().ReadCertificate(cert);
                sm2Cert.publicKey = x509.GetPublicKey();
                sm2Cert.certId = x509.SerialNumber.ToString(10); //这里转10进账，有啥其他进制要求的自己改改
                return sm2Cert;
            }
            catch (Exception e)
            {
                //log.Error("ReadSm2X509Cert error: " + e.Message, e);
                return null;
            }
        }

        public static byte[] ZeroIv(string algo)
        {

            try
            {
                IBufferedCipher cipher = CipherUtilities.GetCipher(algo);
                int blockSize = cipher.GetBlockSize();
                byte[] iv = new byte[blockSize];
                Arrays.Fill(iv, 0);
                return iv;
            }
            catch (Exception e)
            {
                //log.Error("ZeroIv error: " + e.Message, e);
                return null;
            }
        }


        public class Sm2Vo
        {
            public string sm2_x;
            public string sm2_y;
        }


        /**
         * BASE64格式公钥转换为裸公钥
         * @param sm2Key
         * @return
         */
        private static Sm2Vo parseBase64TRawKey(string sm2Key)
        {
            if (null == sm2Key)
            {
                return null;
            }

            string sm2_asn1 = Hex.ToHexString(Convert.FromBase64String(sm2Key));
            if (!sm2_asn1.StartsWith(SM2_KEY_TITLE))
            {
                return null;
            }
            Sm2Vo sm2Cert = new Sm2Vo();

            string sm2_xy = sm2_asn1.Substring(SM2_KEY_TITLE.Length, sm2_asn1.Length - SM2_KEY_TITLE.Length);
            sm2Cert.sm2_x = sm2_xy.Substring(0, sm2_xy.Length / 2);
            sm2Cert.sm2_y = sm2_xy.Substring(sm2_xy.Length / 2, sm2_xy.Length - sm2_xy.Length / 2);

            return sm2Cert;
        }

        /**
         * 加签
         */
        public static string generateSmSign(string str)
        {

            AsymmetricKeyParameter SMprivateKey = GetPrivatekeyFromD(new BigInteger(SM_PRIVATE_KEY, 16));

            //1.国密签名
            byte[] msg = Encoding.UTF8.GetBytes(str);
            //签名 USER_ID 应使用国密局推荐 ID，即“1234567812345678”
            byte[] userId = Encoding.UTF8.GetBytes(SM_USER_ID);
            byte[] sig = SignSm3WithSm2(msg, userId, SMprivateKey);

            //国密加签结果
            string c = Convert.ToBase64String(signRawToAsn1(sig));
            return c;
        }

        /**
         * 验签
         */
        public static bool verifySmSign(string rawMsg, string signedStr)
        {
            byte[] sig2 = Convert.FromBase64String(signedStr);

            Sm2Vo sm2Vo = parseBase64TRawKey(SM_PUBLIC_KEY);
            string privateKeyRawX = sm2Vo.sm2_x;
            string privateKeyRawY = sm2Vo.sm2_y;
            AsymmetricKeyParameter SMPbkey = GetPublickeyFromXY(new BigInteger(privateKeyRawX, 16), new BigInteger(privateKeyRawY, 16));

            byte[] sig3 = signAsn12Raw(sig2);
            byte[] msg = Encoding.UTF8.GetBytes(rawMsg);
            //签名 USER_ID 应使用国密局推荐 ID，即“1234567812345678”
            byte[] userId = Encoding.UTF8.GetBytes(SM_USER_ID);
            bool flag = VerifySm3WithSm2(msg, userId, sig3, SMPbkey);
            return flag;
        }

    }
}