C#版本的discuz authcode函数

    根据网上流传甚广的一个版本修改,修正了设置加密串过期时间expiry没有效果的问题 。>>源码<<

代码
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Text;

namespace API.Common
{
    
public enum DiscuzAuthcodeMode { Encode, Decode };

    
/// <summary>
    
/// C#版本 discuz authcode函数。根据网上版本修正设置expiry无效问题。by pwg17
    
/// </summary>
    public class Authcode
    {
        
private static Encoding encoding = Encoding.GetEncoding("gbk");

        
public Authcode()
        {
        }

        
/// <summary>
        
/// 从字符串的指定位置截取指定长度的子字符串
        
/// </summary>
        
/// <param name="str">原字符串</param>
        
/// <param name="startIndex">子字符串的起始位置</param>
        
/// <param name="length">子字符串的长度</param>
        
/// <returns>子字符串</returns>
        private static string CutString(string str, int startIndex, int length)
        {
            
if (startIndex >= 0)
            {
                
if (length < 0)
                {
                    length 
= length * -1;
                    
if (startIndex - length < 0)
                    {
                        length 
= startIndex;
                        startIndex 
= 0;
                    }
                    
else
                    {
                        startIndex 
= startIndex - length;
                    }
                }

                
if (startIndex > str.Length)
                {
                    
return "";
                }
            }
            
else
            {
                
if (length < 0)
                {
                    
return "";
                }
                
else
                {
                    
if (length + startIndex > 0)
                    {
                        length 
= length + startIndex;
                        startIndex 
= 0;
                    }
                    
else
                    {
                        
return "";
                    }
                }
            }

            
if (str.Length - startIndex < length)
            {
                length 
= str.Length - startIndex;
            }

            
return str.Substring(startIndex, length);
        }

        
/// <summary>
        
/// 从字符串的指定位置开始截取到字符串结尾的了符串
        
/// </summary>
        
/// <param name="str">原字符串</param>
        
/// <param name="startIndex">子字符串的起始位置</param>
        
/// <returns>子字符串</returns>
        private static string CutString(string str, int startIndex)
        {
            
return CutString(str, startIndex, str.Length);
        }

        
/// <summary>
        
/// MD5函数
        
/// </summary>
        
/// <param name="str">原始字符串</param>
        
/// <returns>MD5结果</returns>
        public static string MD5(string str)
        {
            
byte[] b = encoding.GetBytes(str);
            b 
= new System.Security.Cryptography.MD5CryptoServiceProvider().ComputeHash(b);
            
string ret = "";
            
for (int i = 0; i < b.Length; i++)
            {
                ret 
+= b[i].ToString("x").PadLeft(2'0');
            }
            
return ret;
        }

        
/// <summary>
        
/// 用于 RC4 处理密码
        
/// </summary>
        
/// <param name="pass">密码字串</param>
        
/// <param name="kLen">密钥长度,一般为 256</param>
        
/// <returns></returns>
        private static Byte[] GetKey(Byte[] pass, Int32 kLen)
        {
            Byte[] mBox 
= new Byte[kLen];

            
for (Int64 i = 0; i < kLen; i++)
            {
                mBox[i] 
= (Byte)i;
            }
            Int64 j 
= 0;
            
for (Int64 i = 0; i < kLen; i++)
            {
                j 
= (j + mBox[i] + pass[i % pass.Length]) % kLen;
                Byte temp 
= mBox[i];
                mBox[i] 
= mBox[j];
                mBox[j] 
= temp;
            }
            
return mBox;
        }

        
/// <summary>
        
/// 生成随机字符
        
/// </summary>
        
/// <param name="lens">随机字符长度</param>
        
/// <returns>随机字符</returns>
        private static string RandomString(int lens)
        {
            
char[] CharArray = { 'a''b''c''d''e''f''g''h''j''k''l''m''n''o''p''q''r''s''t''u''v''w''x''y''z''A''B''C''D''E''F''G''H''J''K''L''M''N''O''P''Q''R''S''T''U''V''W''X''Y''Z''0''1''2''3''4''5''6''7''8''9' };
            
int clens = CharArray.Length;
            
string sCode = "";
            Random random 
= new Random();
            
for (int i = 0; i < lens; i++)
            {
                sCode 
+= CharArray[random.Next(clens)];
            }
            
return sCode;
        }

        
/// <summary>
        
/// 使用 authcode 方法对字符串加密
        
/// </summary>
        
/// <param name="source">原始字符串</param>
        
/// <param name="key">密钥</param>
        
/// <param name="expiry">加密字串有效时间,单位是秒</param>
        
/// <returns>加密结果</returns>
        public static string DiscuzAuthcodeEncode(string source, string key, int expiry)
        {
            
return DiscuzAuthcode(source, key, DiscuzAuthcodeMode.Encode, expiry);

        }

        
/// <summary>
        
/// 使用 Discuz authcode 方法对字符串加密
        
/// </summary>
        
/// <param name="source">原始字符串</param>
        
/// <param name="key">密钥</param>
        
/// <returns>加密结果</returns>
        public static string DiscuzAuthcodeEncode(string source, string key)
        {
            
return DiscuzAuthcode(source, key, DiscuzAuthcodeMode.Encode, 0);

        }

        
/// <summary>
        
/// 使用 Discuz authcode 方法对字符串解密
        
/// </summary>
        
/// <param name="source">原始字符串</param>
        
/// <param name="key">密钥</param>
        
/// <returns>解密结果</returns>
        public static string DiscuzAuthcodeDecode(string source, string key)
        {
            
return DiscuzAuthcode(source, key, DiscuzAuthcodeMode.Decode, 0);

        }

        
/// <summary>
        
/// 使用 变形的 rc4 编码方法对字符串进行加密或者解密
        
/// </summary>
        
/// <param name="source">原始字符串</param>
        
/// <param name="key">密钥</param>
        
/// <param name="operation">操作 加密还是解密</param>
        
/// <param name="expiry">密文有效期, 加密时候有效, 单 位 秒,0 为永久有效</param>
        
/// <returns>加密或者解密后的字符串</returns>
        private static string DiscuzAuthcode(string source, string key, DiscuzAuthcodeMode operation, int expiry)
        {
            
if (source == null || key == null)
            {
                
return "";
            }

            
int ckey_length = 4;
            
string keya, keyb, keyc, cryptkey, result;

            key 
= MD5(key);
            keya 
= MD5(CutString(key, 016));
            keyb 
= MD5(CutString(key, 1616));
            keyc 
= ckey_length > 0 ? (operation == DiscuzAuthcodeMode.Decode ? CutString(source, 0, ckey_length) : RandomString(ckey_length)) : "";

            cryptkey 
= keya + MD5(keya + keyc);

            
if (operation == DiscuzAuthcodeMode.Decode)
            {
                
byte[] temp;
                
try
                {
                    temp 
= System.Convert.FromBase64String(CutString(source, ckey_length));
                }
                
catch
                {
                    
try
                    {
                        temp 
= System.Convert.FromBase64String(CutString(source + "=", ckey_length));
                    }
                    
catch
                    {
                        
try
                        {
                            temp 
= System.Convert.FromBase64String(CutString(source + "==", ckey_length));
                        }
                        
catch
                        {
                            
return "";
                        }
                    }
                }

                result 
= encoding.GetString(RC4(temp, cryptkey));

                
long timestamp = long.Parse(CutString(result, 010));

                
if ((timestamp == 0 || timestamp - UnixTimestamp() > 0&& CutString(result, 1016== CutString(MD5(CutString(result, 26+ keyb), 016))
                {
                    
return CutString(result, 26);
                }
                
else
                {
                    
return "";
                }
            }
            
else
            {
                source 
= (expiry == 0 ? "0000000000" : (expiry + UnixTimestamp()).ToString()) + CutString(MD5(source + keyb), 016+ source;
                
byte[] temp = RC4(encoding.GetBytes(source), cryptkey);
                
return keyc + System.Convert.ToBase64String(temp);
            }
        }

        
/// <summary>
        
/// RC4 原始算法
        
/// </summary>
        
/// <param name="input">原始字串数组</param>
        
/// <param name="pass">密钥</param>
        
/// <returns>处理后的字串数组</returns>
        private static Byte[] RC4(Byte[] input, String pass)
        {
            
if (input == null || pass == nullreturn null;

            
byte[] output = new Byte[input.Length];
            
byte[] mBox = GetKey(encoding.GetBytes(pass), 256);

            
// 加密
            Int64 i = 0;
            Int64 j 
= 0;
            
for (Int64 offset = 0; offset < input.Length; offset++)
            {
                i 
= (i + 1% mBox.Length;
                j 
= (j + mBox[i]) % mBox.Length;
                Byte temp 
= mBox[i];
                mBox[i] 
= mBox[j];
                mBox[j] 
= temp;
                Byte a 
= input[offset];
                
//Byte b = mBox[(mBox[i] + mBox[j] % mBox.Length) % mBox.Length];
                
// mBox[j] 一定比 mBox.Length 小,不需要在取模
                Byte b = mBox[(mBox[i] + mBox[j]) % mBox.Length];
                output[offset] 
= (Byte)((Int32)a ^ (Int32)b);
            }

            
return output;
        }


        
private static string AscArr2Str(byte[] b)
        {
            
return System.Text.UnicodeEncoding.Unicode.GetString(
             System.Text.ASCIIEncoding.Convert(System.Text.Encoding.ASCII,
             System.Text.Encoding.Unicode, b)
             );
        }

        
public static long UnixTimestamp()
        {
            DateTime dtStart 
= TimeZone.CurrentTimeZone.ToLocalTime(new DateTime(197011));
            DateTime dtNow 
= DateTime.Parse(DateTime.Now.ToString());
            TimeSpan toNow 
= dtNow.Subtract(dtStart);
            
string timeStamp = toNow.Ticks.ToString();
            
return long.Parse(timeStamp.Substring(0, timeStamp.Length - 7));
        }

        
public static string urlencode(string str)
        {
            
//php的urlencode不同于HttpUtility.UrlEncode
            
//return HttpUtility.UrlEncode(str);

            
string tmp = string.Empty;
            
string strSpecial = "_-.1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
            
for (int i = 0; i < str.Length; i++)
            {
                
string crt = str.Substring(i, 1);
                
if (strSpecial.Contains(crt))
                    tmp 
+= crt;
                
else
                {
                    
byte[] bts = encoding.GetBytes(crt);
                    
foreach (byte bt in bts)
                    {
                        tmp 
+= "%" + bt.ToString("X");
                    }
                }
            }
            
return tmp;
        }

        
public static long time()
        {
            TimeSpan ts 
= new TimeSpan(System.DateTime.UtcNow.Ticks - new DateTime(197011000).Ticks);
            
return (long)ts.TotalMilliseconds;
        }
    }
}


posted @ 2010-09-06 14:52  切忌浮躁  阅读(904)  评论(0编辑  收藏  举报