using System;
using System.Security.Cryptography;
using System.Text;

public class Test
{
	static void Main( string[] args )
	{
	    string data = "hello";
	    Encrypt(data);
	}
	
	static void Encrypt( string data )
	{
	    PaddingMode padding = PaddingMode.PKCS7;
	    CipherMode cipherMode = CipherMode.ECB;
	    int size = 128;
	
	    Console.WriteLine("input: '" + data + "'");
	
	    string officialKey = "9840822c-14fc-49ac-9d68-ac532f9f171e";
	    Console.WriteLine("key: '" + officialKey + "'");
	
	    Console.WriteLine("block size: '16'");
	    Console.WriteLine( "padding: '11'" );
	
	    var utf8dataBytes = Encoding.UTF8.GetBytes(data);
	    var utf8data = Encoding.UTF8.GetString(utf8dataBytes);
	    Console.WriteLine("utf8 json: '" + utf8data + "'");
	
	    Console.WriteLine("encoded key (utf8): " + officialKey);
	
	    var utf8KeyBytes = Encoding.UTF8.GetBytes(officialKey);
	
	    var myMD5 = MD5.Create();
	    var md5HashOfKey = myMD5.ComputeHash(utf8KeyBytes);
	
	    Console.WriteLine( "md5 hash of key (raw): " + DumpBinary(md5HashOfKey) );
	    Console.WriteLine("md5 hash of key (base64): " + Convert.ToBase64String(md5HashOfKey));
	    Console.WriteLine("BitConverter.ToString(md5HashOfKey): " + BitConverter.ToString(md5HashOfKey));
	    Console.WriteLine("BitConverter.ToString(md5HashOfKey).Replace(): " + BitConverter.ToString(md5HashOfKey).Replace("-",""));
	
	    byte[] encryptedBlob = null;
		
	    using ( var aes = new AesManaged() )
	    {
	        try
	        {
	            aes.Padding = PaddingMode.PKCS7;
	            aes.Mode = CipherMode.ECB;
	            aes.KeySize = 256;
	            aes.BlockSize = 128;
				aes.Key = Encoding.ASCII.GetBytes(BitConverter.ToString(md5HashOfKey).Replace("-","").ToLower());
	            
	            //aes.IV = new byte[] { 0,0,0,0, 0,0,0,0, 0,0,0,0, 0,0,0,0 };
	
	            var bytes = utf8dataBytes;
	            //var bytes = ForcePaddingManually( utf8dataBytes );
	
	            var cxform = aes.CreateEncryptor();
	            encryptedBlob = cxform.TransformFinalBlock( bytes, 0, bytes.Length );
	            Console.WriteLine("finished" + encryptedBlob.Length);
	        }
	        catch (Exception e)
	        {
	            Console.WriteLine("{0} Exception caught.", e);
	        }
	        finally
	        {
	            aes.Clear();
	        }
	    }
	
	    //var encryptedBlob = AesAlgo.Encrypt( data, md5HashOfKey, padding, cipherMode, size );
	    Console.WriteLine("mcrypt (raw): " + DumpBinary(encryptedBlob));
	    Console.WriteLine("mcrypt: " + Encoding.UTF8.GetString(encryptedBlob));
	
	    var encryptedBase64 = Convert.ToBase64String(encryptedBlob);
	    Console.WriteLine( "presid: " + encryptedBase64 );
	
	    var encodedEncryptedBlob = encryptedBase64.Replace( "+", "-" ).Replace( "/", "_" );
	    Console.WriteLine( "sid: " + encodedEncryptedBlob );
	    Console.WriteLine("COMPLETE!");
	}
	
	static byte[] ForcePaddingManually( byte[] data )
	{
	    // force padding manually to test that PKCS7 works like we are expecting
	    var pad = ( 16 - data.Length % 16 ) % 16;
	    var bytes = new byte[data.Length + pad];
	    for ( int i = 0; i < data.Length; ++i )
	    {
	        bytes[i] = data[i];
	    }
	    for ( int i = data.Length; i < data.Length + pad; ++i )
	    {
	        bytes[i] = (byte)pad;
	    }
	
	    return bytes;
	}
	
	static string DumpBinary( byte[] data )
	{
	    var sb = new StringBuilder();
	    for ( int i = 0; i < data.Length; ++i )
	    {
	        sb.Append( data[i].ToString( "X2" ) );
	    }
	    return sb.ToString();
	}
}