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

using Discuz.Common;
 
namespace Discuz.Common
{ 
	/// <summary> 
	/// 加密
	/// </summary> 
	public class AES
	{ 
		//默认密钥向量
		private static byte[] Keys = { 0x41, 0x72, 0x65, 0x79, 0x6F, 0x75, 0x6D, 0x79, 0x53, 0x6E, 0x6F, 0x77, 0x6D, 0x61, 0x6E, 0x3F };

		public static string Encode(string encryptString, string encryptKey)
		{
			encryptKey = Utils.GetSubString(encryptKey, 32, "");
			encryptKey = encryptKey.PadRight(32, ' ');

			RijndaelManaged rijndaelProvider = new RijndaelManaged();
			rijndaelProvider.Key = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 32));
			rijndaelProvider.IV = Keys;
			ICryptoTransform rijndaelEncrypt = rijndaelProvider.CreateEncryptor();
 
			byte[] inputData = Encoding.UTF8.GetBytes(encryptString);
			byte[] encryptedData = rijndaelEncrypt.TransformFinalBlock(inputData,0,inputData.Length);

			return Convert.ToBase64String(encryptedData);
		}
	
		public static string Decode(string decryptString, string decryptKey)
        {
            if (decryptString == string.Empty)
            {
                return string.Empty;
            }
			try
			{
				decryptKey = Utils.GetSubString(decryptKey, 32, "");
				decryptKey = decryptKey.PadRight(32, ' ');

				RijndaelManaged rijndaelProvider = new RijndaelManaged();
				rijndaelProvider.Key = Encoding.UTF8.GetBytes(decryptKey);
				rijndaelProvider.IV = Keys;
				ICryptoTransform rijndaelDecrypt = rijndaelProvider.CreateDecryptor();
 
				byte[] inputData = Convert.FromBase64String(decryptString);
				byte[] decryptedData = rijndaelDecrypt.TransformFinalBlock(inputData,0,inputData.Length);

				return Encoding.UTF8.GetString(decryptedData);
			}
			catch
			{
				return "";
			}

		}

	}

	/// <summary> 
	/// 加密
	/// </summary> 
	public class DES
	{ 
		//默认密钥向量
		private static byte[] Keys = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
		
		/// <summary>
		/// DES加密字符串
		/// </summary>
		/// <param name="encryptString">待加密的字符串</param>
		/// <param name="encryptKey">加密密钥,要求为8位</param>
		/// <returns>加密成功返回加密后的字符串,失败返回源串</returns>
		public static string Encode(string encryptString, string encryptKey)
		{
			encryptKey = Utils.GetSubString(encryptKey, 8, "");
			encryptKey = encryptKey.PadRight(8, ' ');
			byte[] rgbKey = Encoding.UTF8.GetBytes(encryptKey.Substring(0, 8));
			byte[] rgbIV = Keys;
			byte[] inputByteArray = Encoding.UTF8.GetBytes(encryptString);
			DESCryptoServiceProvider dCSP = new DESCryptoServiceProvider();
			MemoryStream mStream = new MemoryStream();
			CryptoStream cStream = new CryptoStream(mStream, dCSP.CreateEncryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
			cStream.Write(inputByteArray, 0, inputByteArray.Length);
			cStream.FlushFinalBlock();
			return Convert.ToBase64String(mStream.ToArray());
		
		}

		/// <summary>
		/// DES解密字符串
		/// </summary>
		/// <param name="decryptString">待解密的字符串</param>
		/// <param name="decryptKey">解密密钥,要求为8位,和加密密钥相同</param>
		/// <returns>解密成功返回解密后的字符串,失败返源串</returns>
		public static string Decode(string decryptString, string decryptKey)
		{
			try
			{
				decryptKey = Utils.GetSubString(decryptKey, 8, "");
				decryptKey = decryptKey.PadRight(8, ' ');
				byte[] rgbKey = Encoding.UTF8.GetBytes(decryptKey);
				byte[] rgbIV = Keys;
				byte[] inputByteArray = Convert.FromBase64String(decryptString);
				DESCryptoServiceProvider DCSP = new DESCryptoServiceProvider();
		
				MemoryStream mStream = new MemoryStream();
				CryptoStream cStream = new CryptoStream(mStream, DCSP.CreateDecryptor(rgbKey, rgbIV), CryptoStreamMode.Write);
				cStream.Write(inputByteArray, 0, inputByteArray.Length);
				cStream.FlushFinalBlock();
				return Encoding.UTF8.GetString(mStream.ToArray());
			}
			catch
			{
				return "";
			}		
		}
	} 
}