Flippingbook downloader

using System;
using System.Globalization;
using System.IO;
using System.IO.Compression;
using System.Linq;
using System.Net;
using System.Text;
using System.Xml;

namespace ConsoleApplication87
{
    class Program
    {
        static void Main(string[] args)
        {
            string baseUrl = args.Last();

            Console.Write(">");

            var wc = new WebClient();

            byte[] propSwf = wc.DownloadData(baseUrl + "assets/flash/properties.swf");
            Console.Write("*");

            propSwf[0] = 0x50;
            propSwf[1] = 0x4B;
            propSwf[2] = 0x03;
            propSwf[3] = 0x04;

            var pms = new MemoryStream();
            new ZipArchive(new MemoryStream(propSwf)).Entries[0].Open().CopyTo(pms);
            var propXml = Encoding.UTF8.GetString(pms.ToArray().Skip(3).ToArray());

            XmlDocument doc = new XmlDocument();
            doc.LoadXml(propXml);

            int pageCount = doc.SelectNodes("/Properties/bookProperties/pages/elements/page").Count;

            byte[] fbSwf = wc.DownloadData(baseUrl + "flash/flippingbook.swf");
            Console.Write("*");

            var fms = new MemoryStream(fbSwf);
            fms.Seek(10, SeekOrigin.Begin);
            var z = new DeflateStream(fms, CompressionMode.Decompress);
            var ufms = new MemoryStream();
            z.CopyTo(ufms);
            var ufm = ufms.ToArray();

            bool encrypted = true;
            if (ufm[0x7EDBC] == 0x66)
                ufms.Seek(0x7ED9B, SeekOrigin.Begin);
            else if (ufm[0x7ED9B] == 0x66)
                encrypted = false;
            else if (ufm[0x81458] == 0x54)
                ufms.Seek(0x81411, SeekOrigin.Begin);
            else
            {
                Console.WriteLine("Fail");
                return;
            }

            int so = 0;
            int sx = 0;

            if (encrypted)
            {
                byte[] keyRaw = new byte[32];
                ufms.Read(keyRaw, 0, 32);
                string key = Encoding.ASCII.GetString(keyRaw);

                so = 8 + int.Parse(key.Substring(0, 2), NumberStyles.HexNumber) % 8;
                sx = int.Parse(key.Substring(4, 2), NumberStyles.HexNumber);
            }

            Directory.CreateDirectory("pages");

            for (int i = 1; i <= pageCount; i++)
            {
                var fileName = "page" + i.ToString("0000") + "_l.jpg";
                var filePath = "pages\\" + fileName;
                if (File.Exists(filePath))
                {
                    Console.Write("-");
                    continue;
                }

                byte[] v = wc.DownloadData(baseUrl + "assets/flash/pages/" + fileName);

                if (encrypted)
                {
                    int a = so;
                    int x = sx + 1;
                    while (a < v.Length)
                    {
                        v[a] = (byte)(v[a] ^ x++);
                        a = a + ((a ^ sx) & 3) + 1;
                    }
                }

                File.WriteAllBytes(filePath, v);
                Console.Write(".");
            }
            Console.WriteLine("Done");
        }
    }
}