using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Security.Cryptography;
using System.IO;

namespace Utils.Security
{
	/// <summary>
	/// DES加密。方法二
	/// </summary>
	public class DES2
	{
		/// <summary>
		/// 加密字符串
		/// </summary>
		public string EncryptString(string pToEncrypt, string sKey)//加密字符串
		{
			var des = new DESCryptoServiceProvider();
			var inputByteArray = Encoding.Default.GetBytes(pToEncrypt);
			des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);
			des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);
			var ms = new MemoryStream();
			var cs = new CryptoStream(ms, des.CreateEncryptor(), CryptoStreamMode.Write);
			cs.Write(inputByteArray, 0, inputByteArray.Length);
			cs.FlushFinalBlock();
			var ret = new StringBuilder();
			foreach (byte b in ms.ToArray()) {
				ret.AppendFormat("{0:X2}", b);
			}
			return ret.ToString();
		}

		/// <summary>
		/// 解密字符串
		/// </summary>
		public string DecryptString(string pToDecrypt, string sKey)//解密字符串
		{
			var des = new DESCryptoServiceProvider();

			var inputByteArray = new byte[pToDecrypt.Length / 2];
			for (int x = 0; x < pToDecrypt.Length / 2; x++) {
				int i = (Convert.ToInt32(pToDecrypt.Substring(x * 2, 2), 16));
				inputByteArray[x] = (byte)i;
			}

			des.Key = ASCIIEncoding.ASCII.GetBytes(sKey);
			des.IV = ASCIIEncoding.ASCII.GetBytes(sKey);
			var ms = new MemoryStream();
			var cs = new CryptoStream(ms, des.CreateDecryptor(), CryptoStreamMode.Write);
			cs.Write(inputByteArray, 0, inputByteArray.Length);
			cs.FlushFinalBlock();

			return System.Text.Encoding.Default.GetString(ms.ToArray());
		}


	}
}