Discuz! Passport 通行证整合(10)

    //------------------------------------以下为一些关键函数------------------------------
    // 将字符串转换为byte数组    
    public byte[] strToByteAry(string str){
        return Encoding.Default.GetBytes(str);
    }

   // c# dz通信证编码函数
   public string passport_encrypt(string txt, string key){
        byte[] randomNumber = new byte[1];
        RNGCryptoServiceProvider Gen = new RNGCryptoServiceProvider();
        Gen.GetBytes(randomNumber);
        int rand = Convert.ToInt32(randomNumber[0]);
        string encrypt_key = md5(rand.ToString());

byte[] txtAry = strToByteAry(txt);
        byte[] encryAry = strToByteAry(encrypt_key);
        int j = 0;
        int ctr = 0;
        byte[] tmp = new byte[2 * txtAry.Length];
        for (int i = 0; i < txtAry.Length; i++)
        {
            ctr = ctr == encryAry.Length ? 0 : ctr;
            tmp[j++] = encryAry[ctr];
            tmp[j++] = xor(txtAry[i], encryAry[ctr++]);
        }
        return Convert.ToBase64String(passport_key(tmp, key));
    }

    // c# dz通行证解码函数
    public string passport_decrypt(string txt, string key){
        byte[] t = Convert.FromBase64String(txt);
        byte[] btxt = passport_key(t, key);
        byte[] btmp = new byte[btxt.Length];
        int j = 0;
        for (int i = 0; i < btxt.Length; i++, j++)
            btmp[j] = xor(btxt[i], btxt[++i]);
        return Encoding.Default.GetString(btmp);
    }

    // c# dz通行证密匙处理函数   
    public byte[] passport_key(byte[] btxt, string key){
        key = md5(key);
        byte[] keyAry = strToByteAry(key);
        int ctr = 0;
        byte[] tmp = new byte[btxt.Length];
        for (int i = 0; i < btxt.Length; i++){
            ctr = (ctr == keyAry.Length) ? 0 : ctr;
            tmp[i] = xor(btxt[i], keyAry[ctr++]);
        }
        return tmp;
    }

    // 针对byte的异或    
    public byte xor(byte a, byte b){
        return Convert.ToByte(a ^ b);
    }

    // 获取UNIX时间戳   
    public string time(){
        DateTime dtStart = TimeZone.CurrentTimeZone.ToLocalTime(new DateTime(1970, 1, 1));
        DateTime dtNow = DateTime.Parse(DateTime.Now.ToString());
        TimeSpan toNow = dtNow.Subtract(dtStart);
        string timeStamp = toNow.Ticks.ToString();
        timeStamp = timeStamp.Substring(0, timeStamp.Length - 7);
        return timeStamp;
    }

    // md5加密
    public string md5(string str){
        MD5 md5Hasher = MD5.Create();
        string re="";
        byte[] data = md5Hasher.ComputeHash(Encoding.Default.GetBytes(str));
        for (int i = 0; i < data.Length; i++)
            re += data[i].ToString("x2");       
        return re;
    }
}