using System;  
    using System.Collections.Generic;  
    using System.Linq;  
    using System.Text;  
    using System.Security.Cryptography;  
    using System.IO;  
      
      
    namespace AESDemo  
    {  
        public static class AESHelper  
        {  
            /// <summary>  
            /// AES加密  
            /// </summary>  
            /// <param name="Data">被加密的明文</param>  
            /// <param name="Key">密钥</param>  
            /// <param name="Vector">向量</param>  
            /// <returns>密文</returns>  
            public static Byte[] AESEncrypt(Byte[] Data, String Key, String Vector)  
            {  
                Byte[] bKey = new Byte[32];  
                Array.Copy(Encoding.UTF8.GetBytes(Key.PadRight(bKey.Length)), bKey, bKey.Length);  
                Byte[] bVector = new Byte[16];  
                Array.Copy(Encoding.UTF8.GetBytes(Vector.PadRight(bVector.Length)), bVector, bVector.Length);  
      
      
                Byte[] Cryptograph = null; // 加密后的密文  
      
      
                Rijndael Aes = Rijndael.Create();  
                try  
                {  
                    // 开辟一块内存流  
                    using (MemoryStream Memory = new MemoryStream())  
                    {  
                        // 把内存流对象包装成加密流对象  
                        using (CryptoStream Encryptor = new CryptoStream(Memory,  
                          Aes.CreateEncryptor(bKey, bVector),  
                          CryptoStreamMode.Write))  
                        {  
                            // 明文数据写入加密流  
                            Encryptor.Write(Data, 0, Data.Length);  
                            Encryptor.FlushFinalBlock();  
      
      
                            Cryptograph = Memory.ToArray();  
                        }  
                    }  
                }  
                catch  
                {  
                    Cryptograph = null;  
                }  
      
      
                return Cryptograph;  
            }  
      
      
            /// <summary>  
            /// AES解密  
            /// </summary>  
            /// <param name="Data">被解密的密文</param>  
            /// <param name="Key">密钥</param>  
            /// <param name="Vector">向量</param>  
            /// <returns>明文</returns>  
            public static Byte[] AESDecrypt(Byte[] Data, String Key, String Vector)  
            {  
                Byte[] bKey = new Byte[32];  
                Array.Copy(Encoding.UTF8.GetBytes(Key.PadRight(bKey.Length)), bKey, bKey.Length);  
                Byte[] bVector = new Byte[16];  
                Array.Copy(Encoding.UTF8.GetBytes(Vector.PadRight(bVector.Length)), bVector, bVector.Length);  
      
      
                Byte[] original = null; // 解密后的明文  
      
      
                Rijndael Aes = Rijndael.Create();  
                try  
                {  
                    // 开辟一块内存流，存储密文  
                    using (MemoryStream Memory = new MemoryStream(Data))  
                    {  
                        // 把内存流对象包装成加密流对象  
                        using (CryptoStream Decryptor = new CryptoStream(Memory,  
                        Aes.CreateDecryptor(bKey, bVector),  
                        CryptoStreamMode.Read))  
                        {  
                            // 明文存储区  
                            using (MemoryStream originalMemory = new MemoryStream())  
                            {  
                                Byte[] Buffer = new Byte[1024];  
                                Int32 readBytes = 0;  
                                while ((readBytes = Decryptor.Read(Buffer, 0, Buffer.Length)) > 0)  
                                {  
                                    originalMemory.Write(Buffer, 0, readBytes);  
                                }  
      
      
                                original = originalMemory.ToArray();  
                            }  
                        }  
                    }  
                }  
                catch  
                {  
                    original = null;  
                }  
      
      
                return original;  
            }  
        }  
    }  
      
      
    不使用向量的方式：  
    public static class AESCrypto  
        {  
    /// <summary>  
    /// IV向量为固定值  
    /// </summary>  
            //private static byte[] _iV = {  
            //    85, 60, 12, 116,  
            //    99, 189, 173, 19,  
            //    138, 183, 232, 248,  
            //    82, 232, 200, 242  
            //};  
      
      
            public static byte[] Decrypt(byte[] encryptedBytes, byte[] key)  
            {  
    MemoryStream mStream = new MemoryStream( encryptedBytes );  
    //mStream.Write( encryptedBytes, 0, encryptedBytes.Length );  
    //mStream.Seek( 0, SeekOrigin.Begin );  
    RijndaelManaged aes = new RijndaelManaged( );  
                aes.Mode = CipherMode.ECB;  
                aes.Padding = PaddingMode.PKCS7;  
                aes.KeySize = 128;  
    aes.Key = key;  
    //aes.IV = _iV;  
    CryptoStream cryptoStream = new CryptoStream( mStream, aes.CreateDecryptor( ), CryptoStreamMode.Read );  
    try {  
      
      
    byte[] tmp = new byte[ encryptedBytes.Length + 32 ];  
    int len = cryptoStream.Read( tmp, 0, encryptedBytes.Length + 32 );  
    byte[] ret = new byte[ len ];  
    Array.Copy( tmp, 0, ret, 0, len );  
    return ret;  
    }  
    finally {  
    cryptoStream.Close( );  
    mStream.Close( );  
    aes.Clear( );  
    }  
    }  
      
      
            public static byte[] Encrypt(byte[] plainBytes, byte[] key)  
            {  
                MemoryStream mStream = new MemoryStream();  
                RijndaelManaged aes = new RijndaelManaged();  
      
      
                aes.Mode = CipherMode.ECB;  
                aes.Padding = PaddingMode.PKCS7;  
                aes.KeySize = 128;  
                //aes.Key = _key;  
      
      
                aes.Key = key;  
                //aes.IV = _iV;  
                CryptoStream cryptoStream = new CryptoStream(mStream, aes.CreateEncryptor(), CryptoStreamMode.Write);  
                try  
                {  
                    cryptoStream.Write(plainBytes, 0, plainBytes.Length);  
                    cryptoStream.FlushFinalBlock();  
                    return mStream.ToArray();  
                }  
                finally  
                {  
                    cryptoStream.Close();  
                    mStream.Close();  
                    aes.Clear();  
                }  
            }  
        }