using System;

public class Program

{

    public static void Main()

    {

        var secret = "!secret!";

        String timestamp = "ARCA" + ((long)DateTimeOffset.Now.ToUnixTimeSeconds()).ToString();

        var encrypted = AES.EncryptStringToString(timestamp, secret);

        Console.WriteLine("Stringa originale: {0}", timestamp);

        Console.WriteLine("Stringa criptata : {0}",encrypted);

​

        var decrypted = AES.DecryptStringToString(encrypted, secret);

        Console.WriteLine("Stringa decriptata : {0}",decrypted);

    }

​

}

​

internal static class AES

{

    private static readonly System.Text.Encoding encoding = new System.Text.UTF8Encoding();

​

    internal static String EncryptStringToString(String msg, String pwd) { return Convert.ToBase64String(EncryptBytesToBytes(encoding.GetBytes(msg), encoding.GetBytes(pwd))); }

    internal static String EncryptStringToString(String msg, Byte[] pwd) { return Convert.ToBase64String(EncryptBytesToBytes(encoding.GetBytes(msg), pwd)); }

​

    internal static Byte[] EncryptStringToBytes(String msg, String pwd) { return EncryptBytesToBytes(encoding.GetBytes(msg), encoding.GetBytes(pwd)); }

    internal static Byte[] EncryptStringToBytes(String msg, Byte[] pwd) { return EncryptBytesToBytes(encoding.GetBytes(msg), pwd); }

​

    internal static String EncryptBytesToString(Byte[] msg, String pwd) { return Convert.ToBase64String(EncryptBytesToBytes(msg, encoding.GetBytes(pwd))); }

    internal static String EncryptBytesToString(Byte[] msg, Byte[] pwd) { return Convert.ToBase64String(EncryptBytesToBytes(msg, pwd)); }

​

    internal static Byte[] EncryptBytesToBytes(Byte[] msg, String pwd) { return EncryptBytesToBytes(msg, encoding.GetBytes(pwd)); }

    internal static Byte[] EncryptBytesToBytes(Byte[] msg, Byte[] pwd)

    {

        using (var hashProvider = new System.Security.Cryptography.SHA256CryptoServiceProvider())

        using (var aesAlgorithm = new System.Security.Cryptography.AesCryptoServiceProvider())

        {

            aesAlgorithm.Mode = System.Security.Cryptography.CipherMode.ECB; // or (better) CBC

            aesAlgorithm.Padding = System.Security.Cryptography.PaddingMode.PKCS7;

            // aesAlgorithm.IV = encoding.GetBytes("XOXOXOXOXOXOXOXO"); // in caso Mode = CBC

            aesAlgorithm.Key = hashProvider.ComputeHash(pwd);

            using (var encryptor = aesAlgorithm.CreateEncryptor())

                return encryptor.TransformFinalBlock(msg, 0, msg.Length);

        }

    }

​

    internal static String DecryptStringToString(String msg, String pwd) { return encoding.GetString(DecryptBytesToBytes(Convert.FromBase64String(msg), encoding.GetBytes(pwd))); }

    internal static String DecryptStringToString(String msg, Byte[] pwd) { return encoding.GetString(DecryptBytesToBytes(Convert.FromBase64String(msg), pwd)); }

​

    internal static Byte[] DecryptStringToBytes(String msg, String pwd) { return DecryptBytesToBytes(Convert.FromBase64String(msg), encoding.GetBytes(pwd)); }

    internal static Byte[] DecryptStringToBytes(String msg, Byte[] pwd) { return DecryptBytesToBytes(Convert.FromBase64String(msg), pwd); }

​

    internal static String DecryptBytesToString(Byte[] msg, String pwd) { return encoding.GetString(DecryptBytesToBytes(msg, encoding.GetBytes(pwd))); }

    internal static String DecryptBytesToString(Byte[] msg, Byte[] pwd) { return encoding.GetString(DecryptBytesToBytes(msg, pwd)); }

​

    internal static Byte[] DecryptBytesToBytes(Byte[] msg, String pwd) { return DecryptBytesToBytes(msg, encoding.GetBytes(pwd)); }

    internal static Byte[] DecryptBytesToBytes(Byte[] msg, Byte[] pwd)

    {

        using (var hashProvider = new System.Security.Cryptography.SHA256CryptoServiceProvider())

        using (var aesAlgorithm = new System.Security.Cryptography.AesCryptoServiceProvider())

        {

            aesAlgorithm.Mode = System.Security.Cryptography.CipherMode.ECB; // or (better) CBC

            aesAlgorithm.Padding = System.Security.Cryptography.PaddingMode.PKCS7;

            // aesAlgorithm.IV = encoding.GetBytes("XOXOXOXOXOXOXOXO"); // in caso Mode = CBC

            aesAlgorithm.Key = hashProvider.ComputeHash(pwd);

            using (var decryptor = aesAlgorithm.CreateDecryptor())

            return decryptor.TransformFinalBlock(msg, 0, msg.Length);

        }

    }

}

​