출처 : http://h5bak.tistory.com/148

key 부분은 24자리 문자가 들어가고 24자리가 안되면 =을 마지막에 채워서 24자리를 맞추어준다.

using System;

using System.Collections.Generic;

using System.IO;

using System.Linq;

using System.Security.Cryptography;

using System.Text;

public class AES

{

public static string Encrypt(string Input, string key)

{

RijndaelManaged aes = new RijndaelManaged();

aes.KeySize = 256;

aes.BlockSize = 128;

aes.Mode = CipherMode.CBC;

aes.Padding = PaddingMode.PKCS7;

aes.Key = Encoding.UTF8.GetBytes(key);

aes.IV = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

var encrypt = aes.CreateEncryptor(aes.Key, aes.IV);

byte[] xBuff = null;

using (var ms = new MemoryStream())

{

using (var cs = new CryptoStream(ms, encrypt, CryptoStreamMode.Write))

{

byte[] xXml = Encoding.UTF8.GetBytes(Input);

cs.Write(xXml, 0, xXml.Length);

}

xBuff = ms.ToArray();

}

string Output = Convert.ToBase64String(xBuff);

return Output;

}

public static string Decrypt(string Input, string key)

{