KB0001 Các phương pháp mã hóa chuỗi

Dạng 1 Có Authentication
Step1:Encode
        public string EnCryptMD5(string strEnCrypt, string key)
        {
            try
            {
                byte[] keyArr;
                byte[] EnCryptArr = UTF8Encoding.UTF8.GetBytes(strEnCrypt);
                MD5CryptoServiceProvider MD5Hash = new MD5CryptoServiceProvider();
                keyArr = MD5Hash.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
                TripleDESCryptoServiceProvider tripDes = new TripleDESCryptoServiceProvider();
                tripDes.Key = keyArr;
                tripDes.Mode = CipherMode.ECB;
                tripDes.Padding = PaddingMode.PKCS7;
                ICryptoTransform transform = tripDes.CreateEncryptor();
                byte[] arrResult = transform.TransformFinalBlock(EnCryptArr, 0, EnCryptArr.Length);
                return Convert.ToBase64String(arrResult, 0, arrResult.Length);
            }
            catch (Exception ex) { }
            return "";
        }
Step2:Decode
        public string DeCryptMD5(string strDecypt, string key)
        {
            try
            {
                byte[] keyArr;
                byte[] DeCryptArr = Convert.FromBase64String(strDecypt);
                MD5CryptoServiceProvider MD5Hash = new MD5CryptoServiceProvider();
                keyArr = MD5Hash.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
                TripleDESCryptoServiceProvider tripDes = new TripleDESCryptoServiceProvider();
                tripDes.Key = keyArr;
                tripDes.Mode = CipherMode.ECB;
                tripDes.Padding = PaddingMode.PKCS7;
                ICryptoTransform transform = tripDes.CreateDecryptor();
                byte[] arrResult = transform.TransformFinalBlock(DeCryptArr, 0, DeCryptArr.Length);
                return UTF8Encoding.UTF8.GetString(arrResult);
            }
            catch (Exception ex) { }
            return "";
        }

Dạng 2 Không cần Authentication

fig 1:String to Base 64

        public  string EncodeStringToBase64(string src)
        {
            byte[] b = Encoding.Unicode.GetBytes(src);
            return Convert.ToBase64String(b);
        }
        public  string DecodeBase64ToString(string src)
        {
            byte[] b = Convert.FromBase64String(src);
            return Encoding.Unicode.GetString(b);
        }

fig 2:Codec UTF8

        public  string EncodeTo64UTF8(string m_enc)
        {
            byte[] toEncodeAsBytes =
            System.Text.Encoding.UTF8.GetBytes(m_enc);
            string returnValue =
            System.Convert.ToBase64String(toEncodeAsBytes);
            return returnValue;
        }
        public  string DecodeFrom64(string m_enc)
        {
            byte[] encodedDataAsBytes =
            System.Convert.FromBase64String(m_enc);
            string returnValue =
            System.Text.Encoding.UTF8.GetString(encodedDataAsBytes);
            return returnValue;
        }

fig 3:Codec UTF32

        public  string EncodeToUTF32(string m_enc)
        {
            byte[] toEncodeAsBytes =
            System.Text.Encoding.UTF32.GetBytes(m_enc);
            string returnValue =
            System.Convert.ToBase64String(toEncodeAsBytes);
            return returnValue;
        }
        public  string DecodeFromUTF32(string m_enc)
        {
            byte[] encodedDataAsBytes =
            System.Convert.FromBase64String(m_enc);
            string returnValue =
            System.Text.Encoding.UTF32.GetString(encodedDataAsBytes);
            return returnValue;
        }

fig 4:Int to base64

        public static string IntToBase64(int src)
        {
            byte[] b = BitConverter.GetBytes(src);
            return Convert.ToBase64String(b);
        }
        public static int Base64ToInt(string src)
        {
            byte[] b = Convert.FromBase64String(src);
            return BitConverter.ToInt32(b, 0);
        }

fig 5:Using RSA key

System.Security.Cryptography.RSACryptoServiceProvider Provider = new System.Security.Cryptography.RSACryptoServiceProvider();
Provider.ImportParameters(your_rsa_key);byte[] encrypted = Provider.Encrypt(System.Text.Encoding.UTF8.GetBytes("Hello World!"), true);
string decrypted =System.Text.Encoding.UTF8.GetString(Provider.Decrypt(encrypted, true));

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