$Id: faq.sgml,v 1.13 2002/03/17 00:22:20 hal9 Exp $ By: Junkbuster Developers The FAQ document gives users and developers alike answers to frequently asked questions about the Internet Junkbuster. Internet Junkbuster is a web proxy with advanced filtering capabilities for protecting privacy, filtering web page content, managing cookies, controlling access, and removing ads, banners, pop-ups and other obnoxious Internet Junk. Junkbuster has a very flexible configuration and can be customized to suit individual needs and tastes. Internet Junkbuster has application for both stand-alone systems and multi-user networks. You can find the latest version of the document at http://ijbswa.sourceforge.net/faq/. Please see the Contact section in the user-manual if you want to contact the developers. The original Junkbuster was a product of Junkbusters Corporation (tm). Development of this effort stopped as of version 2.0.2. Stefan Walherr started the ijbswa project on Sourceforge to rekindle development. Other developers subsequently joined with Stefan, and have since added many new features and enhancements. All the old features remain. The new Junkbuster still blocks ads and banners, still manages cookies, and protects privacy. But, these are all enhanced, and many new features have been added, all in the same vein. The configuration has changed significantly. This is something that users will notice right off the bat. The blocklist file does not exist any more. This is replaced by actions files, such as ijb.actions. This is where most of the per site configuration is now. Integrated browser based configuration and control utility (http://i.j.b). Browser-based tracing of rule and filter effects. Blocking of annoying pop-up browser windows. HTTP/1.1 compliant (most, but not all 1.1 features are supported). Support for Perl Compatible Regular Expressions in the configuration files, and generally a more sophisticated and flexible configuration syntax over previous versions. GIF de-animation. Web page content filtering (removes banners based on size, invisible web-bugs, JavaScript, pop-ups, status bar abuse, etc.) Bypass many click-tracking scripts (avoids script redirection). Multi-threaded (POSIX and native threads). Auto-detection and re-reading of config file changes. User-customizable HTML templates (e.g. 404 error page). Improved cookie management features (e.g. session based cookies). Builds from source on most UNIX-like systems. Packages available for: Linux (RedHat, SuSE, or Debian), Windows, Sun Solaris, Mac OSX, OS/2, HP-UX 11 and AmigaOS. In addition, the configuration is much more powerful and versatile over-all. When you connect to a web site with Junkbuster, you are really connecting to your locally running version of Junkbuster. Junkbuster intercepts your requests for the web page, and relays that to the real web site. The web site sends the HTTP data stream back to Junkbuster, where Junkbuster can work its magic before it relays this data back to your web browser. Since Junkbuster sits between you and the WWW, it is in a position to intercept and completely manage all web traffic and HTTP content before it gets to your browser. Junkbuster uses various programming methods to do this, all of which is under your control via the various configuration files. Modern browsers do indeed have some of the same functionality as Junkbuster. Maybe this is adequate for you. But Junkbuster is much more verstatile and powerful, and can do a number of things that browsers just can't. In addition, a proxy is good choice if you use multiple browsers, or have a LAN with multiple computers. This way all the configuration is in one place, and you don't have to maintain a similar configuration for possibly many browsers. Junkbuster is licensed under the GNU General Public License (GPL). It is free to use, copy, modify or distribute as you wish. There is no warranty of any kind, expressed, implied or otherwise. That is something that would cost real money ;-) There is no registration either. Junkbuster really is free in every respect! We recommend you uninstall the old Junkbuster first to minimize conflicts and confusion. You may want to save your old configuration files for future reference. The configuration is substantially changed. See the user-manual for platform specific installation instructions. [FIXME: This is meant for after the name change!] If you set up the Junkbuster to run on the computer you browse from (rather than your ISP's server or some networked computer on a LAN), the proxy will be on localhost (which is the special name used by every computer on the Internet to refer to itself) and the port will be 8118 (unless you have told the Internet Junkbuster to run on a different port with the listen-address config option). When configuring your browser's proxy settings you typically enter the word localhost in the boxes next to HTTP and Secure (HTTPS) and then the number 8118 for port. Junkbuster can also be used to proxy for a Local Area Network. In this case, your would enter either the IP address of the LAN host where Junkbuster is running, or the equivalent hostname. Port assignment would be same as above. Junkbuster does not currently handle protocols such as FTP, SMTP, IM, IRC, ICQ, or other Internet protocols. No. These will not work. You will need to re-enter your old data into the new configuration structure. Fillme. Fillme. Fillme. Configuring the Internet Junkbuster is not easy. To help you get started, we provide you with three different default configurations. The following table shows you, which features are enabled in each configuration. Feature ijb.action ijb-basic.action ijb-intermediate.action ijb-advanced.action ad-filtering ? x x x blank image ? x x x de-animate GIFs ? x x x referer forging ? x x x jon's +no-cookies-keep (i.e. session cookies only) ? x x x no-popup windows ? x x fast redirects ? x x hide-referrer ? x x hide-useragent ? x x content-modification ? x feature-x ? feature-y ? feature-z ? What I don't understand, is how I can browser edit the config file as a regular user, while the whole /etc/junkbuster hierarchy belongs to the user "junkbuster", with only 644 perms. When you use the browser-based editor, JunkBuster itself is writing to the config files. Because JunkBuster is running as the user "junkbuster", it can update the config files. If you don't like this, setting "enable-edit-actions 0" in the config file will disable the browser-based editor. If you're that paranoid, you should also consider setting "enable-remote-toggle 0" to prevent browser-based enabling/disabling of JunkBuster. Note that normally only local users can connect to JunkBuster, so this is not (normally) a security problem. Using the default filtering configuration, I noticed considerable delays in page requests compared to the old IJB. Loading pages with large contents seemed to take forever, then suddenly delivering all the content at once. The whole content must be loaded in order to filter, and nothing is is sent to the browser during this time. The loading time does not really change in real numbers, but the feeling is different, because most browsers are able to start rendering incomplete content, giving the user a feeling of "it works". To modify the content of a page (i.e. make frames resizeable again, etc.) and not just replace ads, the Internet Junkbuster needs to download the entire page first, do its content magic and then send the page to the browser. Since JunkBuster sits between your web browser and the Internet, it can be programmed to handle certain pages specially. With recent versions of JunkBuster (version 2.9.x), you can get some information about JunkBuster and change some settings by going to http://i.j.b/ or, equivalently, http://ijbswa.sourceforge.net/config/ (Note that i.j.b is far easier to type but may not work in some configurations). These pages are *not* forwarded to a server on the internet - instead they are handled by a special web server which is built in to JunkBuster. If you are not running JunkBuster, then http://i.j.b/ will fail, and http://ijbswa.sourceforge.net/config/ will return a web page telling you you're not running JunkBuster. If you have version 2.0.2, then the equivalent is http://example.com/show-proxy-args (but you get far less information, and you should really consider upgrading to 2.9.x). Fillme. Fillme. Well, helping the team is always a good idea. We welcome new developers, RPM gurus or documentation makers. Simply get an account on sourceforge.net and mail your id to the developer mailing list. Once we have added you to the team, you'll have write access to the CVS repository, and together we'll find a suitable task for you. No. The format of the blocklists has changed significantly in the versions 2.9.x. Once we have released the new version, there will again be blocklists that you can update automatically. As of now, please discontinue to submit new ad blocking infos. Once we have released the new version, there will again be a form on the website, which you can use to contribute new ads. You cannot hide your IP address with Junkbuster or any other software, since the server needs to know your IP address to send the answer to you. Fortunately there are many publicly usable anonymous proxies out there, which solve the problem by providing a further level of indirection between you and the web server, shared by many people and thus letting your requests "drown" in white noise of unrelated requests as far as user tracking is concerned. Most of them will, however, log your IP address and make it available to the authorities in case you abuse that anonymity for criminal purposes. In fact you can't even rule out that some of them only exist to *collect* information on (those suspicious) people with a more than average preference for privacy. You can find a list of anonymous public proxies at multiproxy.org and many more through Google. No. Your chances of remaining anonymous are greatly improved, but unless you are an expert on Internet security it would be safest to assume that everything you do on the Web can be traced back to you. Junkbuster can remove various information about you, and allows you more freedom to decide which sites you can trust. But it's still possible that web sites can find out who you are. Here's one way this can happen. A few browsers disclose the user's email address in certain situations, such as when transferring a file by FTP. Junkbuster does not filter FTP. If you need this feature, or are concerned about the mail handler of your browser disclosing your email address, you might consider products such as NSClean. Browsers available only as binaries could use non-standard headers to give out any information they can have access to: see the manufacturer's license agreement. It's impossible to anticipate and prevent every breach of privacy that might occur. The professionally paranoid prefer browsers available as source code, because anticipating their behavior is easier. Trust the source, Luke! Definitely. More and more sites use HTTP header content to decide what to display and how to display it. There is many ways that this can be handled, so having hard and fast rules, is tricky. USER AGENT in particular is often used in this way to identify the browser, and adjust content accordingly. Changing this now is not recommended, since so many sites do look for this. You may get undesirable results by changing this. For instance, different browsers use different encodings of Russian and Czech characters, certain web servers convert pages on-the-fly according to the User Agent header. Giving a User Agent with the wrong operating system or browser manufacturer causes some sites in these languages to be garbled; Surfers to Eastern European sites should change it to something closer. Some page access counters work by looking at the REFERER header; they may fail or break if deprived. The weather maps of Intellicast have been blocked by their server when no REFERER or cookie is provided, is another example. There are many, many other ways things can go wrong when trying to fool a web server. If you have problems with a site, you will have to adjust your configuration accordingly. Cookies are probably the most likely adjustment that may be required, but by no means the only one. No, it does not have this ability at all. You want something like Squid for this. And, yes, before you ask, Junkbuster can co-exist with other kinds of proxies like Squid. Either Junkbuster is not running, or your browser is configured for a different port than what Junkbuster is using. The old Junkbuster used port 8000 by default. This has been changed to port 8118 now, due to a conflict with NAS (Network Audio Service), which uses port 8000. If you haven't, you need to change your browser to the new port number, or alternately change Junkbuster's listen-address setting in the default config file. If the ad had been displayed before you added its URL, it will probably be held in cache for some time, so it will be displayed without the need for any request to the server. The best thing to do is try flusing the browser's caches. If this doesn't help, you probably don't have the configuration applied incorrectly. Try pasting the full URL of the offending ad into http://ijbswa.sourceforge.net/config/show-url-info and see if any actions match. Fillme. Please see the user manual for information on how to contact the developers. Please see the user manual for information on Copyright and History. Please see the user manual for information on references.