C#中SM2加解密

发布时间 2023-07-04 16:38:10作者: NangFah
    public class Sm2: IDecryption
    {
        private readonly string _privateKey;
        private readonly Encoding _encoding;
        private readonly string _publickey;

        public Sm2(string privateKey,string publickey,Encoding encoding)
        {
            _privateKey = privateKey;
            _publickey = publickey;
            _encoding = encoding;

        }

        public static AlgKeyPair CreateKeyPair(Encoding encoding)
        {
            var keyPair = SM2.Instance.ecc_key_pair_generator.GenerateKeyPair();
            var privateKeyParameters = (ECPrivateKeyParameters)keyPair.Private;
            var publicKeyParameters = (ECPublicKeyParameters)keyPair.Public;
            var d = privateKeyParameters.D;
            return new AlgKeyPair(encoding.GetString(Hex.Encode(publicKeyParameters.Q.GetEncoded())).ToUpper(),
                encoding.GetString(Hex.Encode(d.ToByteArray())).ToUpper());
        }
        /// <summary>
        /// 解密
        /// </summary>
        /// <param name="ciphertext"></param>
        /// <returns></returns>
        public string Decrypt(string ciphertext)
        {
           return  _encoding.GetString(SM2Utils.Decrypt(Hex.Decode(_privateKey),
               (Hex.Decode(ciphertext))));
        }


        /// <summary>
        /// 加密
        /// </summary>
        /// <param name="ciphertext"></param>
        /// <returns></returns>
        public string Encrypt(string ciphertext)
        {
            return (SM2Utils.Encrypt(Hex.Decode(_publickey),
                (_encoding.GetBytes(ciphertext))));
        }




        private byte[] ChangeC1C3C2ToC1C2C3(byte[] data)
        {
            const int c1Len = 65;
            const int c3Len = 32;
            var result = new byte[data.Length];
            Array.Copy(data, 0, result, 0, c1Len);
            Array.Copy(data, c1Len + c3Len, result, c1Len, data.Length - c1Len - c3Len);
            Array.Copy(data, c1Len, result, data.Length - c3Len, c3Len);
            return result;
        }

    }