title: Objective C AES CBC Encryption with Zero Padding
body: <p>I am trying to encrypt a string with AES 128 encryption, using CBC mode, with Zero Padding. Sadly, i do not know how to do this, as many attempts have gone unsuccessful. I have code in C# and was wondering whether anyone can help me getting my encryption working. 
  the code:</p>
  
  <pre><code>`using System;
  using System.Security.Cryptography;
  using System.Text;
  using System.IO;
  
  byte[] request = UTF8Encoding.UTF8.GetBytes("{string which needs encrypting}");
  
  byte[] key = UTF8Encoding.UTF8.GetBytes("{key}");
  byte[] iv = UTF8Encoding.UTF8.GetBytes("{iv}");
  
  AesCryptoServiceProvider aes = new AesCryptoServiceProvider();
  
  aes.Key = key;
  aes.IV = iv;
  
  
  aes.Mode = CipherMode.CBC;
  
  aes.Padding = PaddingMode.Zeros;
  
  ICryptoTransform cTransform = aes.CreateEncryptor();
  
  byte[] result = cTransform.TransformFinalBlock(request, 0, request.Length);
  
  aes.Clear()
  
  string encryptedRequest = Convert.ToBase64String(result, 0, result.Length);`
  </code></pre>
  
  <p>ive looked a common crypto, but i cannot see an option to CBC mode [i dont know cccrypto much anyways, maybe i overlook?] 
  thanks;</p>