using System;
using System.IO;
using System.Security.Cryptography;

namespace NcProgramManager
{
        class AesCrypt
        {

            public static byte[] EncryptStringToBytes_Aes(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 Aes object
                // with the specified key and IV.
                using (Aes aesAlg = Aes.Create())
                {
                    aesAlg.Key = Key;
                    aesAlg.IV = IV;

                    // Create an encryptor to perform the stream transform.
                    ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.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 static string DecryptStringFromBytes_Aes(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 Aes object
                // with the specified key and IV.
                using (Aes aesAlg = Aes.Create())
                {
                    aesAlg.Key = Key;
                    aesAlg.IV = IV;

                    // Create a decryptor to perform the stream transform.
                    ICryptoTransform decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.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;
            }
        }
    }
