using System;

using System.Security.Cryptography;

using System.Text;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

    }

            public string EncryptAES(string input, string key = "", string iv = "")

        {

            var rijndaelCipher = new RijndaelManaged

            {

                Mode = CipherMode.CBC,

                Padding = PaddingMode.PKCS7,

                KeySize = 128,

                BlockSize = 128

            };

​

            var pwdBytes = Encoding.UTF8.GetBytes(key);

            var keyBytes = new byte[16];

            var len = pwdBytes.Length;

            if (len > keyBytes.Length) len = keyBytes.Length;

            Array.Copy(pwdBytes, keyBytes, len);

​

            rijndaelCipher.Key = keyBytes;

​

            var ivBytes1 = Encoding.UTF8.GetBytes(iv);

            var keyBytes1 = new byte[16];

​

            var len1 = ivBytes1.Length;

            if (len1 > keyBytes1.Length) len1 = keyBytes1.Length;

            Array.Copy(ivBytes1, keyBytes1, len1);

            rijndaelCipher.IV = ivBytes1;

​

            var transform = rijndaelCipher.CreateEncryptor();

            var plainText = Encoding.UTF8.GetBytes(input);

            var cipherBytes = transform.TransformFinalBlock(plainText, 0, plainText.Length);

            return Convert.ToBase64String(cipherBytes);

        }

}