/*
 * MD5加密
 * 肖俊
 * 2013-6-7
 */
using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

namespace AllBase
{
    public static class Md5Base
    {
        /// <summary>
        /// MD5加密
        /// </summary>
        /// <param name="instring"></param>
        /// <returns></returns>
        public static string GetMd5(string instring)
        {
            byte[] result = Encoding.UTF8.GetBytes(string.IsNullOrEmpty(instring)?"": instring.Trim());
            MD5 md5 = new MD5CryptoServiceProvider();
            byte[] output = md5.ComputeHash(result);
            return BitConverter.ToString(output).Replace("-", "");
        }
        /// <summary>
        /// MD5加密
        /// </summary>
        /// <param name="instring"></param>
        /// <returns></returns>
        //public static string GetMd5X16(string instring)
        //{
        //    string temp = GetMd5(instring);
        //    return temp.Substring(8, 16);
        //}

        /// <summary>
        /// MD5加密
        /// </summary>
        /// <param name="instring"></param>
        /// <returns></returns>
        public static string GetMd5X15(string instring)
        {
            string temp = GetMd5(instring);
            return temp.Substring(8, 15);
        }
        /// <summary>
        /// 解码
        /// </summary>
        /// <param name="code"></param>
        /// <returns></returns>
        public static string DecodeString(string code)
        {
            try
            {
                string code1 =
                code.Trim().Replace("_1/", "c")
                    .Replace("_2/", "Y")
                    .Replace("_3/", "A")
                    .Replace("_4/", "Z")
                    .Replace("_5/", "h")
                    .Replace("_6/", "n")
                    .Replace("_7/", "I")
                    .Replace("_8/", "l")
                    .Replace("_9/", "t")
                    .Replace("_10/", "e")
                    .Replace("_11/", "K")
                    .Replace("_12/", "r")
                    .Replace("_13/", "o")
                    .Replace("_14/", "q")
                    .Replace("_15/", "W")
                    .Replace("_16/", "+")
                    .Replace("_17/", "H")
                    .Replace("_18/", "m")
                    .Replace("_19/", "F")
                    .Replace("_20/", "x")
                    .Replace("_21/", "v")
                    .Replace("_22/", "B")
                    .Replace("_23/", "=")
                    .Replace("_0/", "_");
                byte[] inArray = Convert.FromBase64String(code1);
                string html = Encoding.UTF8.GetString(inArray);
                html =
                    html.Replace("_1_", "=")
                        .Replace("_2_", "?")
                        .Replace("_3_", "/")
                        .Replace("_4_", ".")
                        .Replace("_5_", "&")
                        .Replace("_6_", "<")
                        .Replace("_7_", ">")
                        .Replace("_8_", "'")
                        .Replace("_9_", "\"")
                        .Replace("_", "_0");
                return html;
            }
            catch (Exception e)
            {
                LogSave.Add("解码数据错误："+code);
                return "";
            }
            
        }

        /// <summary>
        /// 加密返回数据
        /// </summary>
        /// <param name="html">密文</param>
        /// <returns></returns>
        public static string EncodeString(string html)
        {
            if (string.IsNullOrEmpty(html))
                return "";
            html =
                html.Replace("_0", "_")
                    .Replace("=", "_1_")
                    .Replace("?", "_2_")
                    .Replace("/", "_3_")
                    .Replace(".", "_4_")
                    .Replace("&", "_5_")
                    .Replace("\\", "_6_")
                    .Replace(">", "_7_")
                    .Replace("'", "_8_")
                    .Replace("\"", "_9_");
            string code = Base64Encode.EncodeBase64(html);
            code =
                code.Replace("c", "_1_")
                    .Replace("Y", "_2_")
                    .Replace("A", "_3_")
                    .Replace("Z", "_4_")
                    .Replace("h", "_5_")
                    .Replace("n", "_6_")
                    .Replace("I", "_7_")
                    .Replace("o", "_8_")
                    .Replace("t", "_9_")
                    .Replace("=", "_0_");
            return code;
        }


        #region EBFB8THEA 加密
        public static string _KEY = "XNNRSAA1";  //密钥
        public static string _IV = "RSABPDD2";   //向量

        /// <summary>
        /// 加密
        /// </summary>
        /// <param name="data">需要加密的文本</param>
        /// <returns></returns>
        public static string EncryptEncode(string data)
        {
            byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(_KEY);
            byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(_IV);

            DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
            int i = cryptoProvider.KeySize;
            MemoryStream ms = new MemoryStream();
            CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateEncryptor(byKey, byIV), CryptoStreamMode.Write);

            StreamWriter sw = new StreamWriter(cst);
            sw.Write(data);
            sw.Flush();
            cst.FlushFinalBlock();
            sw.Flush();
            string strRet = Convert.ToBase64String(ms.GetBuffer(), 0, (int)ms.Length);

            sw.Dispose();
            sw.Close();
            cst.Dispose();
            cst.Close();
            ms.Dispose();
            ms.Close();
            return strRet;
        }

        /// <summary>
        /// 解密
        /// </summary>
        /// <param name="data"></param>
        /// <returns></returns>
        public static string EncryptDecode(string data)
        {
            byte[] byKey = System.Text.ASCIIEncoding.ASCII.GetBytes(_KEY);
            byte[] byIV = System.Text.ASCIIEncoding.ASCII.GetBytes(_IV);
            byte[] byEnc;

            try
            {
                data.Replace("_%_", "/");
                data.Replace("-%-", "#");
                byEnc = Convert.FromBase64String(data);
            }
            catch
            {
                return null;
            }

            DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
            MemoryStream ms = new MemoryStream(byEnc);
            CryptoStream cst = new CryptoStream(ms, cryptoProvider.CreateDecryptor(byKey, byIV), CryptoStreamMode.Read);
            StreamReader sr = new StreamReader(cst);
            var result = sr.ReadToEnd();

            sr.Dispose();
            sr.Close();
            cst.Dispose();
            cst.Close();
            ms.Dispose();
            ms.Close();

            return result;
        }
        #endregion
    }
}