DPM_PADM/WebAPI/Models/Crypto.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Threading.Tasks;

namespace DPMService.Models
{
    public class Crypto
    {

        //public static void Main()
        //{
        //    try
        //    {

        //        string original = "Here is some data to encrypt!";

        //        // Create a new instance of the RijndaelManaged
        //        // class.  This generates a new key and initialization
        //        // vector (IV).
        //        using (RijndaelManaged myRijndael = new RijndaelManaged())
        //        {

        //            myRijndael.GenerateKey();
        //            myRijndael.GenerateIV();
        //            // Encrypt the string to an array of bytes.
        //            byte[] encrypted = EncryptStringToBytes(original, myRijndael.Key, myRijndael.IV);

        //            // Decrypt the bytes to a string.
        //            string roundtrip = DecryptStringFromBytes(encrypted, myRijndael.Key, myRijndael.IV);

        //            //Display the original data and the decrypted data.
        //            Console.WriteLine("Original:   {0}", original);
        //            Console.WriteLine("Round Trip: {0}", roundtrip);
        //        }
        //    }
        //    catch (Exception e)
        //    {
        //        Console.WriteLine("Error: {0}", e.Message);
        //    }
        //}
        public  byte[] EncryptStringToBytes(string plainText, byte[] Key, byte[] IV)
        {
            // Check arguments.
            if (plainText == null || plainText.Length <= 0)
                throw new ArgumentNullException("plainText");
            if (Key == null || Key.Length <= 0)
                throw new ArgumentNullException("Key");
            if (IV == null || IV.Length <= 0)
                throw new ArgumentNullException("IV");
            byte[] encrypted;
            // Create an RijndaelManaged object
            // with the specified key and IV.
            using (RijndaelManaged rijAlg = new RijndaelManaged())
            {
                rijAlg.Key = Key;
                rijAlg.IV = IV;


                // Create an encryptor to perform the stream transform.
                ICryptoTransform encryptor = rijAlg.CreateEncryptor(rijAlg.Key, rijAlg.IV);

                // Create the streams used for encryption.
                using (MemoryStream msEncrypt = new MemoryStream())
                {
                    using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
                    {
                        using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
                        {

                            //Write all data to the stream.
                            swEncrypt.Write(plainText);
                        }
                        encrypted = msEncrypt.ToArray();
                    }
                }
            }

            // Return the encrypted bytes from the memory stream.
            return encrypted;
        }

        public  string DecryptStringFromBytes(byte[] cipherText, byte[] Key, byte[] IV)
        {
            // Check arguments.
            if (cipherText == null || cipherText.Length <= 0)
                throw new ArgumentNullException("cipherText");
            if (Key == null || Key.Length <= 0)
                throw new ArgumentNullException("Key");
            if (IV == null || IV.Length <= 0)
                throw new ArgumentNullException("IV");

            // Declare the string used to hold
            // the decrypted text.
            string plaintext = null;

            // Create an RijndaelManaged object
            // with the specified key and IV.
            using (RijndaelManaged rijAlg = new RijndaelManaged())
            {
                rijAlg.Key = Key;
                rijAlg.IV = IV;

                // Create a decryptor to perform the stream transform.
                ICryptoTransform decryptor = rijAlg.CreateDecryptor(rijAlg.Key, rijAlg.IV);

                // Create the streams used for decryption.
                using (MemoryStream msDecrypt = new MemoryStream(cipherText))
                {
                    using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                    {
                        using (StreamReader srDecrypt = new StreamReader(csDecrypt))
                        {
                            // Read the decrypted bytes from the decrypting stream
                            // and place them in a string.
                            plaintext = srDecrypt.ReadToEnd();
                        }
                    }
                }
            }

            return plaintext;
        }
    }
}