X-Git-Url: http://www.privoxy.org/gitweb/?p=privoxy.git;a=blobdiff_plain;f=doc%2Fsource%2Ffaq.sgml;h=9da6d3ba923faa3065e49d34e0fa7c9d20544254;hp=1f05afdca208e73ed294a4f3a01595cab21f40e1;hb=4ca1b3964ffd8d2ac27cf2a9f4de9bb7ac67259e;hpb=105aaa1d5c79461a24b21a0a50cb81bb56988981 diff --git a/doc/source/faq.sgml b/doc/source/faq.sgml index 1f05afdc..9da6d3ba 100644 --- a/doc/source/faq.sgml +++ b/doc/source/faq.sgml @@ -1,5 +1,5 @@ + @@ -8,14 +8,17 @@ - - - - + + + + + + +Privoxy"> ]> - Copyright &my-copy; 2001-2006 by - Privoxy Developers + Copyright &my-copy; 2001-2011 by + Privoxy Developers -$Id: faq.sgml,v 2.13 2006/09/04 19:20:33 fabiankeil Exp $ +$Id: faq.sgml,v 2.84 2011/11/13 17:03:54 fabiankeil Exp $ +--> - &p-intro; + What is Privoxy? &p-intro; @@ -134,7 +137,7 @@ Hal. You can find the latest version of the document at http://www.privoxy.org/faq/. Please see the Contact section if you want to - contact the developers. + contact the developers. @@ -147,8 +150,84 @@ Hal. General Information +Who should give &my-app; a try? + + Anyone who is interested in security, privacy, or in + finer-grained control over their web and Internet experience. + + + +Is Privoxy the best choice for +me? + + &my-app; is certainly a good choice, especially for those who want more + control and security. Those with the willingness to read the documentation + and the ability to fine-tune their installation will benefit the most. + + + One of Privoxy's + strengths is that it is highly configurable giving you the ability to + completely personalize your installation. Being familiar with, or at least + having an interest in learning about HTTP and other networking + protocols, HTML, and + Regular + Expressions + will be a big plus and will help you get the most out of &my-app;. + A new installation just includes a very basic configuration. The user + should take this as a starting point only, and enhance it as he or she + sees fit. In fact, the user is encouraged, and expected to, fine-tune the + configuration. + + + Much of Privoxy's configuration can be done + with a Web browser. + But there are areas where configuration is done using a + text editor + to edit configuration files. Also note that the web-based action editor + doesn't use authentication and should only be enabled in environments + where all clients with access to &my-app; listening port can be trusted. + + -What is this new version of <application>Junkbuster</application>? +What is a <quote>proxy</quote>? How does +Privoxy work? + + A web proxy + is a service, based on a software such as &my-app;, that clients + (i.e. browsers) can use instead of connecting to web servers directly. + The clients then ask the proxy to request objects (web pages, images, movies etc) + on their behalf and to forward the data to the clients. + It is a go-between. For details, see + Wikipedia's proxy definition. + + + There are many reasons to use web proxies, such as security (firewalling), + efficiency (caching) and others, and there are any number of proxies + to accommodate those needs. + + + &my-app; is a proxy that is primarily focused on + privacy enhancement, ad and junk elimination and freeing the user from + restrictions placed on his activities. Sitting between your browser(s) and the Internet, + it is in a perfect position to filter outbound personal information that your + browser is leaking, as well as inbound junk. It uses a variety of techniques to do + this, all of which are under your complete control via the various configuration + files and options. Being a proxy also makes it easier to share + configurations among multiple browsers and/or users. + + + + +Does Privoxy do anything more than ad blocking? + + Yes, ad blocking is but one possible use. There are many, many ways &my-app; + can be used to sanitize and customize web browsing. + + + +What is this new version of +<quote><citetitle>Junkbuster</citetitle></quote>? &history; @@ -159,29 +238,29 @@ Hal. Why <quote>Privoxy</quote>? Why change the name from -<application>Junkbuster</application> at all? +Junkbuster at all? - Junkbusters Corporation + Though outdated, Junkbusters Corporation continues to offer their original version of the Internet Junkbuster, so publishing our Junkbuster-derived software under the same name led to confusion. - There are also potential legal complications from the continued use of the - Junkbuster name, which is a registered trademark of + There are also potential legal complications from our use of the + Junkbuster name, which is a registered trademark of Junkbusters Corporation. - There are, however, no objections from Junkbusters Corporation to the + There are, however, no objections from Junkbusters Corporation to the Privoxy project itself, and they, in fact, still share our ideals and goals. - The developers also believed that there are so many improvements over the original - code, that it was time to make a clean break from the past and make + The developers also believed that there are so many improvements over the original + code, that it was time to make a clean break from the past and make a name in their own right. - Privoxy is the + Privoxy is the Privacy Enhancing Proxy. Also, its content modification and junk suppression gives you, the user, more control, more freedom, and allows you to browse your personal and @@ -189,63 +268,29 @@ Hal. - -How does <application>Privoxy</application> differ -from the old <application>Junkbuster?</application> +How does Privoxy differ +from the old Junkbuster? Privoxy picks up where - Junkbuster left off. All the old features remain. + Junkbuster left off. The new Privoxy still blocks ads and banners, - still manages cookies, and still helps protect your privacy. But, these are - all greatly enhanced, and many, many new features have been added, all in the same vein. + still manages cookies, and still + helps protect your privacy. But, most of these features have been enhanced, + and many new ones have been added, all in the same vein. - - The configuration has changed significantly as well. This is something that - users will notice right off the bat if upgrading from - Junkbuster 2.0.x. The blocklist - cookielist, imagelist and much more has been - combined into the actions files, with a completely different - syntax. See the What's New - page for the latest updates. - Privoxy's new features include: - + &newfeatures; -What is a <quote>proxy</quote>? How does -<application>Privoxy</application> work? - - A web proxy is a service, based on a software such as Privoxy, - that clients (i.e. browsers) can use instead of connecting directly to the web - servers on the Internet. The clients then ask the proxy to fetch the objects - they need (web pages, images, movies etc) on their behalf, and when the proxy - has done so, it hands the results back to the client. - - - There are many reasons to use web proxies, such as security (firewalling), - efficiency (caching) and others, and there are just as many different proxies - to accommodate those needs. - - - Privoxy is a proxy that is primarily focused on privacy - protection, junk elimination and freeing the user from restrictions placed on his - activities. Sitting between your browser(s) and the Internet, - it is in a perfect position to filter outbound personal information that your - browser is leaking, as well as inbound junk. It uses a variety of techniques to do - this, all of which are under your control via the various configuration - files and options. - - - - -How does <application>Privoxy</application> know what is +<title id="knows">How does Privoxy know what is an ad, and what is not? Privoxy's approach to blocking ads is twofold: @@ -257,7 +302,8 @@ an ad, and what is not? and the host (blocking the big banner hosting services like doublecklick.net already helps a lot). Privoxy takes advantage of this fact by using URL - patterns to sort out and block the requests for banners. + patterns to sort out and block the requests for things that sound + like they would be ads or banners. Second, banners tend to come in certain sizes. But you @@ -269,12 +315,12 @@ an ad, and what is not? Both of this involves a certain amount of guesswork and is, of course, freely - configurable. + and readily configurable. -Can <application>Privoxy</application> make mistakes? +<title id="mistakes">Can Privoxy make mistakes? This does not sound very scientific. Actually, it's a black art ;-) And yes, it is always possible to have a broad @@ -293,107 +339,227 @@ This does not sound very scientific. - -Will I have to configure <application>Privoxy</application> +<title id="configornot">Will I have to configure Privoxy before I can use it? - No, not really. The default installation should give you a good starting - point, and block most unwanted content. + That depends on your expectations. + The default installation should give you a good starting + point, and block most ads and unwanted content, + but many of the more advanced features are off by default, and require + you to activate them. + + + You do have to set up your browser to use + Privoxy (see the Installation section below). - But you will certainly run into situations where there are false positives, + And you will certainly run into situations where there are false positives, or ads not being blocked that you may not want to see. In these cases, you would certainly benefit by customizing Privoxy's - configuration to more closely match your individual situation. And we would + configuration to more closely match your individual situation. And we encourage you to do this. This is where the real power of Privoxy lies! + +Can Privoxy run as a server on a network? + + Yes, &my-app; runs as a server already, and can easily be configured to + serve more than one client. See + How can I set up Privoxy to act as a proxy for my LAN below. + + + My browser does the same things as -<application>Privoxy</application>. Why should I use -<application>Privoxy</application> at all? +Privoxy. Why should I use Privoxy at all? Modern browsers do indeed have some of the same functionality as Privoxy. Maybe this is - adequate for you. But Privoxy is much more - versatile and powerful, and can do a number of things that browsers just can't. + adequate for you. But Privoxy is very + versatile and powerful, and can probably do a number of things + your browser just can't. + + + In addition, a proxy is good choice if you use multiple browsers, or + have a LAN with multiple computers since &my-app; can run as a server + application. This way all the configuration is in one place, and you don't + have to maintain a similar configuration for possibly many browsers or + users. - 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. + Note, however, that it's recommended to leverage both your browser's + and Privoxy's privacy enhancing features + at the same time. While your browser probably lacks some features + &my-app; offers, it should also be able to do some things more + reliable, for example restricting and suppressing JavaScript. +Why should I trust Privoxy? + + The most important reason is because you have access to + everything, and you can control everything. You can + check every line of every configuration file yourself. You can check every + last bit of source code should you desire. And even if you can't read code, + there should be some comfort in knowing that other people can, + and do read it. You can build the software from scratch, if you want, + so that you know the executable is clean, and that it is + yours. In fact, we encourage this level of scrutiny. It + is one reason we use &my-app; ourselves. + + - -Is there is a license or fee? What about a +<sect2 renderas="sect3" id="license"><title>Is there is a license or fee? What about a warranty? Registration? - Privoxy is licensed under the GNU General Public License (GPL). + Privoxy is free software and licensed under the GNU General Public License (GPL) version 2. It is free to use, copy, modify or distribute as you wish under the terms of this license. Please see the Copyright section for more - information on the license and copyright. Or the LICENSE file + information on the license and copyright. Or the LICENSE file that should be included. There is no warranty of any kind, expressed, implied or otherwise. That is something that would cost real money ;-) There is no registration either. - Privoxy really is free - in every respect! -I would like to help you, what do I do? - -Contribute! + +Can Privoxy remove spyware? Adware? Viruses? - We, of course, welcome donations and could use money for domain registering, - buying software to test Privoxy with, and, of course, - for regular world-wide get-togethers (hahaha). If you enjoy the software and feel - like helping us with a donation, just drop us a note. + No, at least not reliably enough to trust it. &my-app; is not designed to be + a malware removal tool and the default configuration doesn't even try to + filter out any malware. - + + &my-app; could help prevent contact from (known) sites that use such + tactics with appropriate configuration rules, and thus could conceivably + prevent contamination from such sites. However, keeping such a configuration + up to date would require a lot of time and effort that would be better spend + on keeping your software itself up to date so it doesn't have known + vulnerabilities. + + + -Software + +Can I use Privoxy with other ad-blocking software? - If you are a vendor of a web-related software like a browser, web server - or proxy, and would like us to ensure that Privoxy - runs smoothly with your product, you might consider supplying us with a - copy or license. We can't, however, guarantee that we will fix all potential - compatibility issues as a result. + &my-app; should work fine with other proxies and other software in general. - + + But it is probably not necessary to use &my-app; in conjunction with other + ad-blocking products, and this could conceivably cause undesirable results. + It might be better to choose one software or the other and work a little to + tweak its configuration to your liking. + + + Note that this is an advice specific to ad blocking. + + -Would you like to participate? +I would like to help you, what can I do? + +Would you like to participate? - Well, helping the team is always a good idea. We welcome new developers, - packagers, testers, documentation writers or really anyone with a desire to help in - any way. You - DO NOT need to be a programmer. There - are many other tasks available. In fact, the programmers often can't spend - as much time programming because of some of the other, more mundane things - that need to be done, like checking the Tracker feedback sections. + Well, we always need help. There is something for + everybody who wants to help us. We welcome new developers, packagers, + testers, documentation writers or really anyone with a desire to help in + any way. You DO NOT need to be a + programmer. There are many other tasks available. In fact, + the programmers often can't spend as much time programming because of some + of the other, more mundane things that need to be done, like checking the + Tracker feedback sections or responding to user questions on the mailing + lists. + + + So first thing, subscribe to the Privoxy Users + or the Privoxy + Developers mailing list, join the discussion, help out other users, provide general + feedback or report problems you noticed. - So first thing, get an account on SourceForge.net - and mail your id to the developers - mailing list. Then, please read the Developer's Manual, at least - the pertinent sections. + so we don't confuse you with the other name-less users. + + + We also have a Developer's Manual. + While it is partly out of date, it's still worth reading. - Once we have added you to the team, you'll have access to the CVS repository, and - together we'll find a suitable task for you. + Our TODO list + may be of interest to you as well. + Please let us know if you want to work on one of the items listed. + + + + @@ -407,12 +573,16 @@ warranty? Registration? Installation -Which browsers are supported by <application>Privoxy</application>? - - Any browser that can be configured to use a proxy, which - should be virtually all browsers. Direct browser support is not necessary - since Privoxy runs as a separate application and - talks to the browser in the standardized HTTP protocol, just like a web server +Which browsers are supported by Privoxy? + + Any browser that can be configured to use a proxy, which + should be virtually all browsers, including + Firefox, Internet + Explorer, Opera, and + Safari among others. + Direct browser support is not an absolute requirement since + Privoxy runs as a separate application and talks + to the browser in the standardized HTTP protocol, just like a web server does. @@ -426,15 +596,15 @@ Include supported.sgml here: -Can I use <application>Privoxy</application> with my email client? +Can I use Privoxy with my email client? As long as there is some way to set a HTTP proxy for the client, then yes, any application can be used, whether it is strictly speaking a browser or not. Though this may not be the best approach for dealing with some of the common abuses of HTML in email. See How can I configure Privoxy - with Outlook Express? below for more on - this. + with Outlook? below for more on + this. Be aware that HTML email presents a number of unique security and privacy @@ -444,16 +614,17 @@ Include supported.sgml here: -Can I install - <application>Privoxy</application> over <application>Junkbuster</application>? + - -I just installed <application>Privoxy</application>. Is there anything +<sect2 renderas="sect3" id="firststep"> +<title>I just installed Privoxy. Is there anything special I have to do now? - All browsers must be told to use Privoxy - as a proxy by specifying the correct proxy address and port number - in the appropriate configuration area for the browser. See below. - You should also flush your browser's memory and disk cache to get rid of any - cached junk items, and remove any stored cookies. + All browsers should be told to use Privoxy + as a proxy by specifying the correct proxy address and port number + in the appropriate configuration area for the browser. It's possible + to combine &my-app; with a packet filter to intercept HTTP requests + even if the client isn't explicitly configured to use &my-app;, + but where possible, configuring the client is recommended. See + the User Manual for more + details. You should also flush your browser's memory and disk + cache to get rid of any cached junk items, and remove any stored + cookies. - -What is the proxy address of <application>Privoxy</application>? +What is the proxy address of Privoxy? If you set up the Privoxy 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 127.0.0.1 + networked computer on a LAN), the proxy will be on 127.0.0.1 (sometimes referred to as 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 Privoxy - to run on a different port with the listen-address config option). + to itself) and the port will be 8118 (unless you used the listen-address + config option to tell Privoxy to run on + a different port). When configuring your browser's proxy settings you typically enter the word localhost or the IP address 127.0.0.1 in the boxes next to HTTP and Secure (HTTPS) and - then the number 8118 for port. + then the number 8118 for port. This tells your browser to send all web requests to Privoxy instead of directly to the Internet. - Privoxy 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 Privoxy - is running, or the equivalent hostname. Port assignment would be - same as above. Note that Privoxy doesn't - listen on any LAN interfaces by default. + Privoxy 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 Privoxy + is running, or the equivalent hostname, e.g. 192.168.1.1. + Port assignment would be same as above. Note that + Privoxy doesn't listen on any LAN interfaces by + default. Privoxy does not currently handle - any other protocols such as FTP, SMTP, IM, IRC, ICQ, etc. + any other protocols such as FTP, SMTP, IM, IRC, ICQ, etc. -I just installed <application>Privoxy</application>, and nothing is happening. +<title>I just installed Privoxy, and nothing is happening. All the ads are there. What's wrong? - Did you configure your browser to use Privoxy + Did you configure your browser to use Privoxy as a proxy? It does not sound like it. See above. You might also try flushing - the browser's caches to force a full re-reading of pages. You can verify - that Privoxy is running, and your browser - is correctly configured by entering the special URL: - http://p.p/. + the browser's caches to force a full re-reading of pages. You can verify + that Privoxy is running, and your browser + is correctly configured by entering the special URL: + http://p.p/. This should take you to a page titled This is Privoxy.. with access to Privoxy's internal configuration. - If you see this, then you are good to go. If you receive a page saying + If you see this, then you are good to go. If you receive a page saying Privoxy is not running, then the browser is not set up to use your Privoxy installation. If you receive anything else (probably nothing at all), it could either @@ -537,14 +715,14 @@ All the ads are there. What's wrong? on starting Privoxy and browser configuration, see the chapter on starting Privoxy in the - user manual. + User Manual. I get a <quote>Privoxy is not being used</quote> dummy page although -<application>Privoxy</application> is running and being used. +Privoxy is running and being used. First, make sure that Privoxy is really running and @@ -552,7 +730,7 @@ All the ads are there. What's wrong? should see the Privoxy main page. If not, see the chapter on starting Privoxy in the - user manual. + User Manual. @@ -565,12 +743,17 @@ All the ads are there. What's wrong? - The procedure for clearing the cache varies from browser to browser. As an - example, Mozilla users would click + The procedure for clearing the cache varies from browser to browser. For + example, Mozilla/Netscape users would click Edit --> Preferences --> Advanced --> Cache and then click both Clear Memory Cache and Clear Disk Cache. + In some Firefox versions it's + Tools --> Options --> + Privacy --> Cache and + then click Clear Cache Now. + @@ -580,73 +763,44 @@ All the ads are there. What's wrong? Configuration - -Where can I get updated Actions Files? - - Based on your feedback and the continuing development, updated actions files will be - made available on the files section of - our project page. - - - - If you wish to receive an email notification whenever we release updates of - Privoxy or the actions file, subscribe - to our announce mailing list, ijbswa-announce@lists.sourceforge.net. - - - - -Can I use my old config files? - - The syntax, number, and purpose of configuration files has substantially - changed from Junkbuster and early versions - of Privoxy. The old files, like blocklist - will not work at all. If you are upgrading from a 2.0.x version, you will - need to port your configuration data to the new format. Note that even the - pattern syntax has changed! Even configuration files from the 2.9.x versions - will need to be adapted, as configuration syntax has been very much in flow - in the 2.9.x series. - - - Refer to the What's New - page for information on configuration changes that may occur from one release to another. - - - -What is an <quote>actions</quote> file? +What exactly is an <quote>actions</quote> file? + &my-app; utilizes the concept of + actions + that are used to manipulate and control web page data. Actions files - are where various actions - that Privoxy might take while processing a certain + are where these actions + that Privoxy could take while processing a certain request, are configured. Typically, you would define a set of default actions - that apply to all URLs, then add exceptions to these defaults where needed. + that apply globally to all URLs, then add exceptions to these defaults where needed. + There is a wide array of actions available that give the user a high degree + of control and flexibility on how to process each and every web page. - + Actions can be defined on a URL pattern basis, i.e. for single URLs, whole web sites, groups or parts thereof etc. Actions can also be grouped together and then applied to requests matching one or more patterns. There are many possible actions that might apply to any given site. As an example, - if you are blocking cookies as one of your default actions, but need to accept - cookies from a given site, you would need to define an exception for this - site in one of your actions files, preferably in user.action. + if you are blocking cookies + as one of your default actions, but need to accept cookies from a given site, + you would need to define an exception for this site in one of your actions + files, preferably in user.action. -The <quote>actions</quote> concept confuses me. Please list +<title>The <quote>actions</quote> concept confuses me. Please list some of these <quote>actions</quote>. For a comprehensive discussion of the actions concept, please refer to the actions file - chapter in the user - manual. It includes a in the User + Manual. It includes a list of all actions and an actions file tutorial to get you started. @@ -656,7 +810,7 @@ some of these actions. How are actions files configured? What is the easiest -way to do this? +way to do this? Actions files are just text files in a special syntax and can be edited @@ -665,7 +819,10 @@ way to do this? at http://config.privoxy.org/ (Shortcut: http://p.p/) and then select View & - change the current configuration from the menu. + change the current configuration from the menu. Note + that this feature must be explicitly enabled in the main config file + (see enable-edit-actions). @@ -674,32 +831,59 @@ way to do this? There are several different <quote>actions</quote> files. What are the differences? - As of Privoxy v2.9.15, three actions files - are being included, to be used for - different purposes: These are - default.action, the main actions file - which is actively maintained by the Privoxy - developers, user.action, where users are encouraged - to make their private customizations, and standard.action, - which is for internal Privoxy use only. - Please see the actions chapter - in the user manual for a more - detailed explanation. + Please have a look at the the actions chapter + in the User Manual for a detailed explanation. - - Earlier versions included three different versions of the - default.action file. The new scheme allows for - greater flexibility of local configuration, and for browser based - selection of pre-defined aggressiveness levels. - + + +Where can I get updated Actions Files? + + Based on your feedback and the continuing development, updates of + default.action will be + made available from time to time on the files section of + our project page. + + + + If you wish to receive an email notification whenever we release updates of + Privoxy or the actions file, subscribe + to our announce mailing list, ijbswa-announce@lists.sourceforge.net. + + + + +Can I use my old config files? + + The syntax and purpose of configuration files has remained roughly the + same throughout the 3.x series, but backwards compatibility is not guaranteed. + Also each release contains updated, improved versions and it is + therefore strongly recommended to install the newer configuration files + and merge back your modifications. + + + +Why is the configuration so complicated? + + Complicated is in the eye of the beholder. Those that are + familiar with some of the underlying concepts, such as regular expression + syntax, take to it like a fish takes to water. Also, software that tries + hard to be user friendly, often lacks sophistication and + flexibility. There is always that trade-off there between power vs. + easy-of-use. Furthermore, anyone is welcome to contribute ideas and + implementations to enhance &my-app;. + How can I make my Yahoo/Hotmail/Gmail account work? The default configuration shouldn't impact the usability of any of these services. - It will, however, make all cookies temporary, so that your browser will forget your + It may, however, make all cookies + temporary, so that your browser will forget your login credentials in between browser sessions. If you would like not to have to log in manually each time you access those websites, simply turn off all cookie handling for them in the user.action file. An example for yahoo might @@ -711,18 +895,43 @@ the differences? { -crunch-incoming-cookies -crunch-outgoing-cookies -session-cookies-only } .login.yahoo.com + + These kinds of sites are often quite complex and heavy with + Javascript and + thus fragile. So if still a problem, + we have an alias just for such + sticky situations: + + + # Gmail is a _fragile_ site: +# +{ fragile } + # Gmail is ... + mail.google.com + + + Be sure to flush your browser's caches whenever making these kinds of + changes, just to make sure the changes take. + + + Make sure the domain, host and path are appropriate as well. Your browser can + tell you where you are specifically and you should use that information for + your configuration settings. Note that above it is not referenced as + gmail.com, which is a valid domain name. + What's the difference between the -<quote>Cautious</quote>, <quote>Medium</quote> and <quote>Adventuresome</quote> defaults? +Cautious, Medium and Advanced defaults? Configuring Privoxy is not entirely trivial. To help you get started, we provide you with three different default action profiles in the web based actions file editor at http://config.privoxy.org/show-status. See the User - Manual for a list of actions, and how the default + Manual for a list of actions, and how the default profiles are set. @@ -730,21 +939,23 @@ the differences? Where the defaults are likely to break some sites, exceptions for known popular problem sites are included, but in general, the more aggressive your default settings are, the more exceptions - you will have to make later. See the Cautious setting. This is safest and will have the fewest + problems. See the User Manual - for a more deatiled discussion. + for a more detailed discussion. - It should be noted that the Adventuresome profile (formerly known - as the Advanced profile) is not only more - aggressive, but also includes fun and, extreme usage of most of - Privoxy's features. Use at your own risk! + It should be noted that the Advanced profile (formerly known + as the Adventuresome profile) is more + aggressive, and will make use of some of + Privoxy's advanced features. Use at your own risk! - Why can I change the configuration +<sect2 renderas="sect3" id="browseconfig"> <title>Why can I change the configuration with a browser? Does that not raise security issues? It may seem strange that regular users can edit the config files with their @@ -755,21 +966,20 @@ with a browser? Does that not raise security issues? When you use the browser-based editor, Privoxy itself is writing to the config files. Because Privoxy is running as the user privoxy, - it can update the config files. + it can update its own config files. If you run Privoxy for multiple untrusted users (e.g. in - a LAN), you will probably want to turn the web-based editor and remote toggle - features off by setting off by setting enable-edit-actions 0 and enable-remote-toggle 0 in the main configuration file. - Note that in the default configuration, only local users (i.e. those on - localhost) can connect to Privoxy, - so this is not (normally) a security problem. + As of &my-app; 3.0.7 these options are disabled by default. @@ -778,44 +988,66 @@ with a browser? Does that not raise security issues? What is the <filename>default.filter</filename> file? What is a <quote>filter</quote>? The default.filter - file is where filters as supplied by the developers are defined. + file is where filters as supplied by the developers are defined. Filters are a special subset of actions that can be used to modify or - remove, web page content on the fly. Filters apply to anything - in the page source (and optionally both client and server headers), including - HTML tags, and JavaScript. Regular expressions are used to accomplish this. + remove web page content or headers on the fly. Content filters can + be applied to anything in the page source, + header filters can be applied to either server or client headers. + Regular expressions are used to accomplish this. + + There are a number of pre-defined filters to deal with common annoyances. The filters are only defined here, to invoke them, you need to use the filter - action in one of the actions files. Filtering is automatically - disabled for inappropriate MIME types. + action in one of the actions files. Content filtering is automatically + disabled for inappropriate MIME types, but if you know better than Privoxy + what should or should not be filtered you can filter any content you like. + + + Filters should + not be confused with blocks, which + is a completely different action, and is more typically used to block ads and + unwanted sites. - If you are familiar with regular expressions, and HTML, you can look at + If you are familiar with regular expressions, and HTML, you can look at the provided default.filter with a text editor and define your own filters. This is potentially a very powerful feature, but - requires some expertise in both regular expressions and HTML/HTTP. You should - place any modifications to the default filters, or any new ones you create - in a separate file, such as user.filter, so they won't - be overwritten during upgrades. The ability to define multiple filter files - in config is a new feature as of v. 3.0.4. + requires some expertise in both regular expressions and HTML/HTTP. + user.filter, so they won't + be overwritten during upgrades. + The ability to define multiple filter files + in config is a new feature as of v. 3.0.5.]]> - There is no GUI editor option for this part of the configuration, - but you can disable/enable the various pre-defined filters of the included + There is no GUI editor option for this part of the configuration, + but you can disable/enable the various pre-defined filters of the included default.filter file with the web-based actions file editor. + Note that the custom actions editor must be explicitly enabled in + the main config file (see enable-edit-actions). + + + + If you intend to develop your own filters, you might want to have a look at + Privoxy-Filter-Test. - -How can I set up <application>Privoxy</application> to act as a proxy for my +<sect2 renderas="sect3" id="lanconfig"> +<title>How can I set up Privoxy to act as a proxy for my LAN? - By default, Privoxy only responds to requests + By default, Privoxy only responds to requests from 127.0.0.1 (localhost). To have it act as a server for a network, this needs to be changed in the main configuration file. Look for @@ -834,12 +1066,12 @@ with a browser? Does that not raise security issues? - Save the file, and restart Privoxy. Configure + Save the file, and restart Privoxy. Configure all browsers on the network then to use this address and port number. - Alternately, you can have Privoxy listen on + Alternately, you can have Privoxy listen on all available interfaces: @@ -849,10 +1081,10 @@ with a browser? Does that not raise security issues? - And then use Privoxy's + And then use Privoxy's permit-access - feature to limit connections. A firewall in this situation is recommended + url="../user-manual/config.html#PERMIT-ACCESS">permit-access + feature to limit connections. A firewall in this situation is recommended as well. @@ -887,8 +1119,8 @@ with a browser? Does that not raise security issues? If you want to see nothing, then change the set-image-blocker - action to blank. This can be done by editing the - default.action file, or trough the to blank. This can be done by editing the + user.action file, or through the web-based actions file editor. @@ -898,18 +1130,19 @@ with a browser? Does that not raise security issues? Why would anybody want to see a checkerboard pattern? Remember that telling which image is an ad and which - isn't, is mostly guesswork. While we hope that the standard configuration - is rather smart, it can and will make errors. The checkerboard image is visually - decent, but it shows you that and where images were blocked, which can be very + isn't, is an educated guess. While we hope that the standard configuration + is rather smart, it will make occasional mistakes. The checkerboard image is visually + decent, and it shows you where images have been blocked, which can be very helpful in case some navigation aid or otherwise innocent image was - erraneously blocked. Some people might also enjoy seeing how many banners - they don't have to see.. + erroneously blocked. It is recommended for new users so they can + see what is happening. Some people might also enjoy seeing how + many banners they don't have to see. -I see some images being replaced by a text +<title id="blockedbytext">I see some images being replaced with text instead of the checkerboard image. Why and how do I get rid of this? This happens when the banners are not embedded in the HTML code of the @@ -917,7 +1150,7 @@ instead of the checkerboard image. Why and how do I get rid of this? or (i)layers, and these external HTML documents are blocked. Being non-images they get replaced by a substitute HTML page rather than a substitute image, which wouldn't work out technically, since the browser expects and accepts - only HTML when it has requested an HTML document. + only HTML when it has requested an HTML document. The substitute page adapts to the available space and shows itself as a @@ -936,108 +1169,106 @@ instead of the checkerboard image. Why and how do I get rid of this? -Can <application>Privoxy</application> run as a service -on Win2K/NT? +Can Privoxy run as a service +on Win2K/NT/XP? - - Version 3.0.4 introduces full Windows service functionality. - On Windows only, the Privoxy program has two new command line arguments - to install and uninstall Privoxy as a service. - - - Arguments: - - - --install[:service_name] - - - - - --uninstall[:service_name] - - - - - - - After invoking Privoxy with --install, - you will need to bring up the Windows service console to assign the user you - want Privoxy to run under, and whether or not you want it to run whenever the - system starts. You can start the Windows services console with the following command: - services.msc If you do not take the manual step of modifying - Privoxy's service settings, it will not start. Note too that you will need to - give Privoxy a user account that actually exists, or it will not be permitted to - write its log files. +Windows service + functionality. See + the User Manual for details on how to install and configure + Privoxy as a service. - Earlier versions could run as a system service using srvany.exe. + Earlier ]]>3.x versions could run as a system service using srvany.exe. See the discussion at http://sourceforge.net/tracker/?func=detail&atid=361118&aid=485617&group_id=11118, for details, and a sample configuration. - - Version 3.0.1 fixed the problem where the icon and menu where not available - in the taskbar for this usage. - -How can I make <application>Privoxy</application> work with other -proxies like <application>Squid</application> or <application>TOR</application>? +How can I make Privoxy work with other proxies? This can be done and is often useful to combine the benefits of - Privoxy with those of a another proxy. + Privoxy with those of a another proxy, + for example to cache content. See the forwarding chapter - in the user manual which - describes how to do this. + in the User Manual which + describes how to do this. If you intend to use Privoxy with Tor, + please also have a look at + How do I use Privoxy together with Tor. -Can I just set <application>Privoxy</application> to use port 80 +<title>Can I just set Privoxy to use port 80 and thus avoid individual browser configuration? - No, its more complicated than that. This only works with special kinds - of proxies known as transparent proxies (see below). + No, its more complicated than that. This only works with special kinds + of proxies known as intercepting proxies + (see below). -Can <application>Privoxy</application> run as a <quote>transparent +<title>Can Privoxy run as a <quote>transparent </quote> proxy? - No, Privoxy currently does not have this ability, - though it is planned for a future release. Transparent proxies require - special handling of the request headers beyond what - Privoxy is now capable of. + The whole idea of Privoxy is to modify client requests + and server responses in all sorts of ways and therefore + it's not a transparent proxy as described in + RFC 2616. + + + However, some people say transparent proxy when they + mean intercepting proxy. If you are one of them, + please read the next entry. + + + +Can Privoxy run as a <quote>intercepting</quote> proxy? - Chaining Privoxy behind another proxy that has - this ability should work though. - See the forwarding chapter - in the user manual. As - a transparent proxy to be used for chaining we recommend Transproxy - (http://www.transproxy.nlc.net.au/). + Privoxy can't intercept traffic itself, + but it can handle requests that where intercepted and redirected + with a packet filter (like PF or + iptables), as long as the Host + header is present. + + + As the Host header is required by HTTP/1.1 and as most + web sites rely on it anyway, this limitation shouldn't be a problem. + + + Please refer to your packet filter's documentation to learn how to + intercept and redirect traffic into Privoxy. + Afterward you just have to configure Privoxy to + accept + intercepted requests. -How can I configure <application>Privoxy</application> for use with <application>Outlook - Express</application>? +How can I configure Privoxy for use with Outlook? + + Versions of Outlook prior to Office 2007, use + Internet Explorer components to both render HTML, + and fetch any HTTP requests that may be embedded in an HTML email. So however + you have Privoxy configured to work with IE, this + configuration should automatically be shared, at least with older version of + Internet Explorer. + - Outlook Express uses Internet Explorer - components to both render HTML, and fetch any HTTP requests that may be embedded in an HTML email. - So however you have Privoxy configured to work - with IE, this configuration should automatically be shared. + Starting with Office 2007, Microsoft is instead using the MS-Word rendering + engine with Outlook. It is unknown whether this can be configured to use a + proxy. + @@ -1048,30 +1279,77 @@ and thus avoid individual browser configuration? of knowing which particular application makes a request, so there is no way to distinguish between web pages and HTML mail. Privoxy just blindly proxies all requests. In the - case of Outlook Express (see above), OE uses - IE anyway, and there is no way for Privoxy to ever + case of Outlook Express (see above), OE uses + IE anyway, and there is no way for Privoxy to ever be able to distinguish between them (nor could any other proxy type application for that matter). - For a good discussion of some of the issues involved (including privacy and - security issues), see + For a good discussion of some of the issues involved (including privacy and + security issues), see http://sourceforge.net/tracker/?func=detail&atid=211118&aid=629518&group_id=11118. + +I sometimes notice cookies sneaking through. How? + + Cookies can be + set in several ways. The classic method is via the + Set-Cookie HTTP header. This is straightforward, and an + easy one to manipulate, such as the &my-app; concept of + session-cookies-only. + There is also the possibility of using + Javascript to + set cookies (&my-app; calls these content-cookies). This + is trickier because the syntax can vary widely, and thus requires a certain + amount of guesswork. It is not realistic to catch all of these short of + disabling Javascript, which would break many sites. And lastly, if the + cookies are embedded in a HTTPS/SSL secure session via Javascript, they are beyond + Privoxy's reach. + + + All in all, &my-app; can help manage cookies in general, can help minimize + the loss of privacy posed by cookies, but can't realistically stop all + cookies. + + + + +Are all cookies bad? Why? + + No, in fact there are many beneficial uses of + cookies. Cookies are just a + method that browsers can use to store data between pages, or between browser + sessions. Sometimes there is a good reason for this, and the user's life is a + bit easier as a result. But there is a long history of some websites taking + advantage of this layer of trust, and using the data they glean from you and + your browsing habits for their own purposes, and maybe to your potential + detriment. Such sites are using you and storing their data on your system. + That is why the privacy conscious watch from whom those cookies come, and why + they really need to be there. + + + See the + Wikipedia cookie + definition for more. + + + How can I allow permanent cookies for my trusted sites? - There are several actions that relate to cookies. The default behavior is to + There are several actions that relate to cookies. The default behavior is to allow only session cookies, which means the cookies only last - for the current browser session. This eliminates most kinds of abuse related - to cookies. But there may be cases where we want cookies to last. + for the current browser session. This eliminates most kinds of abuse related + to cookies. But there may be cases where you want cookies to last. To disable all cookie actions, so that cookies are allowed unrestricted, - both in and out, for example.com: + both in and out, for example.com: @@ -1079,7 +1357,7 @@ and thus avoid individual browser configuration? .example.com - Place the above in user.action. Note some of these may + Place the above in user.action. Note that some of these may be off by default anyway, so this might be redundant, but there is no harm being explicit in what you want to happen. user.action includes an alias for this situation, called @@ -1092,47 +1370,50 @@ and thus avoid individual browser configuration? Each instance of Privoxy has its own configuration, including such attributes as the TCP port that it listens on. - What you can do is run multiple instances of Privoxy, each with - a unique listen-address and configuration path, and then + What you can do is run multiple instances of Privoxy, each with + a unique + listen-address + configuration setting, and configuration path, and then each of these can have their own configurations. Think of it as per-port configuration. - + Simple enough for a few users, but for large installations, consider having groups of users that might share like configurations. -Can I set-up <application>Privoxy</application> as a whitelist of +<title>Can I set-up Privoxy as a whitelist of <quote>good</quote> sites? - Sure. There are a couple of things you can do for simple whitelisting. + Sure. There are a couple of things you can do for simple white-listing. Here's one real easy one: ############################################################ # Blacklist ############################################################ - { +block } + { +block } / # Block *all* URLs - + ############################################################ # Whitelist ############################################################ - { -block } + { -block } kids.example.com toys.example.com games.example.com - This allows access to only those three sites. + This allows access to only those three sites by first blocking all URLs, and + then subsequently allowing three specific exceptions. - A more interesting approach is Privoxy's - trustfile concept, which incorporates the notion of + Another approach is Privoxy's + trustfile concept, which incorporates the notion of trusted referrers. See the User Manual Trust - documentation. + url="../user-manual/config.html#TRUSTFILE">Trust documentation + for details. These are fairly simple approaches and are not completely foolproof. There @@ -1143,6 +1424,104 @@ and thus avoid individual browser configuration? + +How can I turn off ad-blocking? + + Ad blocking is achieved through a complex application of various &my-app; + actions. These + actions are deployed against simple images, banners, flash animations, + text pages, JavaScript, pop-ups and pop-unders, etc., so its not as simple as + just turning one or two actions off. The various actions that make up + &my-app; ad blocking are hard-coded into the default configuration files. It + has been assumed that everyone using &my-app; is interested in this + particular feature. + + + If you want to do without this, there are several approaches you can take: + You can manually undo the many block rules in + default.action. Or even easier, just create your own + default.action file from scratch without the many ad + blocking rules, and corresponding exceptions. Or lastly, if you are not + concerned about the additional blocks that are done for privacy reasons, you + can very easily over-ride all blocking with the + following very simple rule in your user.action: + + + + # Unblock everybody, everywhere + { -block } + / # UN-Block *all* URLs + + + Or even a more comprehensive reversing of various ad related actions: + + + + # Unblock everybody, everywhere, and turn off appropriate filtering, etc + { -block \ + -filter{banners-by-size} \ + -filter{banners-by-link} \ + allow-popups \ + } + / # UN-Block *all* URLs and allow ads + + + This last action in this compound statement, + allow-popups, is an alias that disables + various pop-up blocking features. + + + + +How can I have custom template pages, like the +<emphasis>BLOCKED</emphasis> page? + + &my-app; templates are specialized text files utilized by + &my-app; for various purposes and can easily be modified using any text + editor. All the template pages are installed in a sub-directory appropriately + named: templates. Knowing something about HTML syntax + will of course be helpful. + + + Be forewarned that the default templates are subject to being overwritten + during upgrades. You can, however, create completely new templates, + place them in another directory and specify the alternate path in the main + config. For details, have a look at the templdir option. + + + + +How can I remove the <quote>Go There Anyway</quote> link from +the <emphasis>BLOCKED</emphasis> page? + + There is more than one way to do it (although Perl is not involved). + + + Editing the BLOCKED template page (see above) may dissuade some users, but + this method is easily circumvented. Where you need this level of control, you + might want to build &my-app; from source, and disable various features that are + available as compile-time options. You should + configure the sources as follows: + + + + ./configure --disable-toggle --disable-editor --disable-force + + + This will create an executable with hard-coded security features so that + &my-app; does not allow easy bypassing of blocked sites, or changing the + current configuration via any connected user's web browser. + + + Finally, all of these features can also be toggled on/off via options in + Privoxy's main config file which + means you don't have to recompile anything. + + + @@ -1153,19 +1532,21 @@ and thus avoid individual browser configuration? Miscellaneous -How much does <application>Privoxy</application> slow my browsing down? This +<title id="slowsme">How much does Privoxy slow my browsing down? This has to add extra time to browsing. How much of an impact depends on many things, including the CPU of the host - system, how agressive the configuration is, which specific actions are being triggered, etc. + system, how aggressive the configuration is, which specific actions are being triggered, + the size of the page, the bandwidth of the connection, etc. - Overall, it should not slow you down any in real terms, and may actually help - speed things up since ads, banners and other junk are not typically being displayed. - The actual processing time required by Privoxy - itself for each page, is relatively small in the overall scheme of things, - and happens very quickly. This is typically more than offset by time saved - not downloading and rendering ad images (if ad blocking is being used). + Overall, it should not slow you down any in real terms, and may actually help + speed things up since ads, banners and other junk are not typically being + retrieved and displayed. The actual processing time required by + Privoxy itself for each page, is relatively small + in the overall scheme of things, and happens very quickly. This is typically + more than offset by time saved not downloading and rendering ad images and + other junk content (if ad blocking is being used). @@ -1173,23 +1554,31 @@ has to add extra time to browsing. url="../user-manual/actions-file.html#FILTER">filter or deanimate-gifs - actions will cause a perceived slowdown, since the entire document needs to be buffered - before displaying. On very large documents, there may be some impact. How - much depends on the page size, the actual definition of the filter(s), etc. See below. - Most other actions have little to no impact on speed. + actions may cause a perceived slowdown, since the entire document + needs to be buffered before displaying. And on very large documents, + filtering may have some measurable impact. How much depends on the page size, + the actual definition of the filter(s), etc. See below. Most other actions + have little to no impact on speed. + + + Also, when filtering is enabled but zlib support isn't available, compression + is often disabled (see prevent-compression). + This can have an impact on speed as well, although it's probably smaller than + you might think. Again, the page size, etc. will determine how much of an impact. -I noticed considerable -delays in page requests compared to the old Junkbuster. What's wrong? +I notice considerable +delays in page requests. What's wrong? If you use any filter action, such as filtering banners by size, web-bugs etc, or the deanimate-gifs - action, the entire document must be loaded into memory in order for the filtering + action, the entire document must be loaded into memory in order for the filtering mechanism to work, and nothing is sent to the browser during this time. @@ -1197,30 +1586,18 @@ delays in page requests compared to the old Junkbuster. What's wrong? the feeling is different, because most browsers are able to start rendering incomplete content, giving the user a feeling of "it works". This effect is more noticeable on slower dialup connections. Extremely large documents - may have some impact on the time to load the page. But the overall difference - should be very minimal. If there is a big impact, then probably some other - problem is contributing. + may have some impact on the time to load the page where there is filtering + being done. But overall, the difference should be very minimal. If there is a + big impact, then probably some other situation is contributing (like + anti-virus software). - Filtering is automatically disabled for inappropriate MIME types. But note + Filtering is automatically disabled for inappropriate MIME types. But note that if the web server mis-reports the MIME type, then content that should not be filtered, could be. Privoxy only knows how to differentiate filterable content because of the MIME type as reported by the server, or because of some configuration setting that enables/disables filtering. - - - - - -I just installed <application>Privoxy</application>, and all my -browsing has slowed to a crawl. What gives? - - This should not happen, and for the overwhelming number of users world-wide, - it does not happen. I would suspect some inadvertent interaction of software - components such as anti-virus software, spyware protectors, personal - firewalls or similar components. Try disabling (or uninstalling) these one - at a time and see if that helps. @@ -1228,11 +1605,11 @@ browsing has slowed to a crawl. What gives? "http://p.p/"? http://config.privoxy.org/ is the - address of Privoxy's built-in user interface, and + address of Privoxy's built-in user interface, and http://p.p/ is a shortcut for it. - Since Privoxy sits between your web browser and the Internet, + Since Privoxy sits between your web browser and the Internet, it can simply intercept requests for these addresses and answer them with its built-in web server. @@ -1245,19 +1622,7 @@ browsing has slowed to a crawl. What gives? hence it could not be intercepted, and you have accessed the real web site at config.privoxy.org. - - With recent versions of Privoxy (version 2.9.x and - later), the user interface features information on the run time status, the - configuration, and even a built-in editor for the actions files. - - - Note that the built-in URLs from earlier versions of Junkbuster - / Privoxy, http://example.com/show-proxy-args and http://i.j.b/, - are no longer supported. If you still use such an old version, you should really consider - upgrading to &p-version;. - -Can <application>Privoxy</application> guarantee I am anonymous? +Can Privoxy guarantee I am anonymous? - No. Your chances of remaining anonymous are greatly improved, but unless you + No. Your chances of remaining anonymous are improved, but unless you chain Privoxy with Tor - or a similar system and know what you're doing when it comes to configuring - the rest of your system, it would be safest to assume that everything you do + or a similar proxy and know what you're doing when it comes to configuring + the rest of your system, you should assume that everything you do on the Web can be traced back to you. Privoxy can remove various information about you, - and allows you more freedom to decide which sites - you can trust, and what details you want to reveal. But it neither - hides your ip address, nor can it guarantee that the rest of the system + and allows you more freedom to decide which sites + you can trust, and what details you want to reveal. But it neither + hides your IP address, nor can it guarantee that the rest of the system behaves correctly. There are several possibilities how a web sites can find out who you are, even if you are using a strict Privoxy configuration and chained it with Tor. - Most of Privoxy's protection can be easily subverted + Most of Privoxy's privacy-enhancing features can be easily subverted by an insecure browser configuration, therefore you should use a browser that can be configured to only execute code from trusted sites, and be careful which sites you trust. For example there is no point in having Privoxy @@ -1374,22 +1749,30 @@ us help you. Your efforts are not wasted, and we do appreciate them. -How do I use <application>Privoxy</application> - together with <application>Tor</application>? + +A test site says I am not using a Proxy. + + Good! Actually, they are probably testing for some other kinds of proxies. + Hiding yourself completely would require additional steps. + + + +How do I use Privoxy + together with Tor? - Before you configure Privoxy to use Tor - (http://tor.eff.org/), - please follow the User Manual chapters + Before you configure Privoxy to use + Tor, + please follow the User Manual chapters 2. Installation and 5. Startup to make sure Privoxy itself is setup correctly. - - If it is, refer to Tor's + + If it is, refer to Tor's extensive documentation to learn how to install Tor, and make sure Tor's logfile says that Tor has successfully opened a circuit and it - [l]ooks like client functionality is working. + looks like client functionality is working. If either Tor or Privoxy @@ -1403,24 +1786,30 @@ us help you. Your efforts are not wasted, and we do appreciate them. If you verified that Privoxy and Tor are working, it is time to connect them. As far as Privoxy is concerned, Tor is just another proxy that can be reached - by socks4 or socks4a. Most likely you are interested in Tor - to increase your anonymity level, therefore you should use socks4a, - to make sure Privoxy's DNS requests are - done through Tor and thus invisible to your local network. + by socks4, socks4a and socks5. Most likely you are interested in Tor + to increase your anonymity level, therefore you should use socks5, to make sure DNS + requests are done through Tor and thus invisible to your + local network. Using socks4a would work too, but with socks5 you get more precise error + messages. + + - Since Privoxy 3.0.4, its configuration (section 5.2) + Since Privoxy 3.0.5, its + main configuration file is already prepared for Tor, if you are using a default Tor configuration and run it on the same - system as Privoxy, you just have to uncomment the line: + system as &my-app;, you just have to edit the + forwarding section + and uncomment the line: -# forward-socks4a / 127.0.0.1:9050 . +# forward-socks5 / 127.0.0.1:9050 . - This is enough to reach the internet, but additionally you should + This is enough to reach the Internet, but additionally you might want to uncomment the following forward rules, to make sure your local network is still reachable through Privoxy: @@ -1434,10 +1823,15 @@ us help you. Your efforts are not wasted, and we do appreciate them. Unencrypted connections to systems in these address ranges will be as (un)secure as the local network is, but the alternative is - that you can't reach the network at all. - If you also want to be able to reach servers in your local - network by using their names, you will need additional - exceptions that look like this: + that your browser can't reach the network at all. Then again, + that may actually be desired and if you don't know for sure + that your browser has to be able to reach the local network, + there's no reason to allow it. + + + If you want your browser to be able to reach servers in your local + network by using their names, you will need additional exceptions + that look like this: @@ -1448,17 +1842,18 @@ us help you. Your efforts are not wasted, and we do appreciate them. Save the modified configuration file and open http://config.privoxy.org/show-status/ in your browser, confirm that Privoxy has reloaded its configuration - and that there are no other forward lines, unless you know that you need them. I everything looks good, + and that there are no other forward lines, unless you know that you need them. If everything looks good, refer to - Tor - Faq 4.2 to learn how to verify that you are really using Tor. + Tor + Faq 4.2 to learn how to verify that you are really using Tor. - Afterwards, please take the time to at least skim through the rest + Afterward, please take the time to at least skim through the rest of Tor's documentation. Make sure you understand what Tor does, why it is no replacement for - application level security, and why you shouldn't use it for unencrypted logins. - + application level security, and why you probably don't want to + use it for unencrypted logins. + ]]> @@ -1466,20 +1861,20 @@ us help you. Your efforts are not wasted, and we do appreciate them. content is being altered? - 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, + Definitely. It is common for sites to use browser type, browser version, + HTTP header content, and various other techniques in order to dynamically + decide what to display and how to display it. What you see, and what I see, + might be very different. There are many, 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 (at least not - further than removing the OS information) is not recommended, since so many - sites do look for it. You may get undesirable results by changing this. + The User-Agent is sometimes used in this way to identify + the browser, and adjust content accordingly. - For instance, different browsers use different encodings of Russian and Czech + Also, different browsers use different encodings of non-English 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 @@ -1489,7 +1884,12 @@ content is being altered? weather maps of Intellicast have been blocked by their server when no Referer or cookie is provided, is another example. (But you can forge both headers without giving information away). There are - many other ways things can go wrong when trying to fool a web server. + many other ways things can go wrong when trying to fool a web server. The + results of which could inadvertently cause pages to load incorrectly, + partially, or even not at all. And there may be no obvious clues as to just + what went wrong, or why. Nowhere will there be a message that says + Turn off fast-redirects or else! + @@ -1498,8 +1898,8 @@ content is being altered? - If you have problems with a site, you will have to adjust your configuration - accordingly. Cookies are probably the most likely adjustment that may + 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. @@ -1507,12 +1907,13 @@ content is being altered? -Can <application>Privoxy</application> act as a <quote>caching</quote> proxy to +<title id="caching">Can Privoxy act as a <quote>caching</quote> proxy to speed up web browsing? - No, it does not have this ability at all. You want something like - Squid for this. And, yes, - before you ask, Privoxy can co-exist + No, it does not have this ability at all. You want something like + Squid or + Polipo for this. + And, yes, before you ask, Privoxy can co-exist with other kinds of proxies like Squid. See the forwarding chapter in the user @@ -1521,61 +1922,46 @@ speed up web browsing? -What about as a firewall? Can <application>Privoxy</application> protect me? +What about as a firewall? Can Privoxy protect me? - Not in the way you mean, or in the way a true firewall can. - Privoxy can help protect your privacy, but not - protect you from intrusion attempts. It is, of course, perfectly possible - and recommended to use both. + Not in the way you mean, or in the way some firewall vendors claim they can. + Privoxy can help protect your privacy, but can't + protect your system from intrusion attempts. It is, of course, perfectly possible + to use both. - - I have large empty spaces / a checkerboard pattern now where ads used to be. Why? - It would be technically possible eliminate the banners in a way that frees - their screen estate in many cases, by doing all banner blocking with filters, - i.e. eliminating the whole image references from the HTML pages instead - of letting them stay in, and blocking the resulting requests for the - banners themselves. + It is technically possible to eliminate banners and ads in a way that frees + their allocated page space. This could easily be done by blocking with + Privoxy's filters, + and eliminating the entire image references from the + HTML page source. - But this would consume considerable CPU resources, would likely destroy - the layout of many web pages which rely on the banners consuming a certain - amount of screen space, and would fail in other cases, where the screen space - is reserved e.g. by tables anyway. Also, making the banners disappear without - a visual trace complicates troubleshooting. + But, this would consume considerably more CPU resources (IOW, slow things + down), would likely destroy the layout of some web pages which rely on the + banners utilizing a certain amount of page space, and might fail in other + cases, where the screen space is reserved (e.g. by HTML tables for instance). + Also, making ads and banners disappear without any trace complicates + troubleshooting, and would sooner or later be problematic. - So we won't support this in the default configuration, but you can of course - define appropriate filters yourself. + The better alternative is to instead let them stay, and block the resulting + requests for the banners themselves as is now the case. This leaves either + empty space, or the familiar checkerboard pattern. + + + So the developers won't support this in the default configuration, but you + can of course define appropriate filters yourself to achieve this. -How can <application>Privoxy</application> filter Secure (HTTPS) URLs? +How can Privoxy filter Secure (HTTPS) URLs? Since secure HTTP connections are encrypted SSL sessions between your browser and the secure site, and are meant to be reliably secure, @@ -1592,35 +1978,35 @@ ads used to be. Why? As far as ad blocking is concerned, this is less of a restriction than it may seem, since ad sources are often identifiable by the host name, and often the banners to be placed in an encrypted page come unencrypted nonetheless - for efficiency reasons, which exposes them to the full power of + for efficiency reasons, which exposes them to the full power of Privoxy's ad blocking. Content cookies (those that are embedded in the actual HTML or JS page content, see filter{content-cookies}), - in an SSL transaction will be impossible to block under these conditions. - Fortunately, this does not seem to be a very common scenario since most + url="../user-manual/actions-file.html#FILTER-CONTENT-COOKIES">filter{content-cookies}), + in an SSL transaction will be impossible to block under these conditions. + Fortunately, this does not seem to be a very common scenario since most cookies come by traditional means. -<application>Privoxy</application> runs as a <quote>server</quote>. How +<title id="secure">Privoxy runs as a <quote>server</quote>. How secure is it? Do I need to take any special precautions? - There are no known exploits that might affect - Privoxy. On Unix-like systems, - Privoxy can run as a non-privileged - user, which is how we recommend it be run. Also, by default - Privoxy only listens to requests - from localhost only. The server aspect of - Privoxy is not itself directly exposed to the - Internet in this configuration. If you want to have + On Unix-like systems, Privoxy can run as a non-privileged + user, which is how we recommend it be run. Also, by default + Privoxy listens to requests from localhost + only. + + + The server aspect of Privoxy is not itself directly + exposed to the Internet in this configuration. If you want to have Privoxy serve as a LAN proxy, this will have to be opened up to allow for LAN requests. In this case, we'd recommend - you specify only the LAN gateway address, e.g. 192.168.1.1, in the main + you specify only the LAN gateway address, e.g. 192.168.1.1, in the main Privoxy configuration file and check all access control and security options. All LAN hosts can then use this as their proxy address @@ -1632,34 +2018,53 @@ secure is it? Do I need to take any special precautions? -How can I temporarily disable <application>Privoxy</application>? +Can I temporarily disable Privoxy? - The easiest way is to access Privoxy with your - browser by using the remote toggle URL: + + The easiest way to do that is to point your browser + to the remote toggle URL: http://config.privoxy.org/toggle. - See the Bookmarklets section - of the User Manual for an easy way to access this - feature. + + + See the Bookmarklets section + of the User Manual for an easy way to access this + feature. Note that this is a feature that may need to be enabled in the main + config file. + -When <quote>disabled</quote> is <application>Privoxy</application> totally +<title>When <quote>disabled</quote> is Privoxy totally out of the picture? - No, this just means all filtering and actions are disabled. - Privoxy is still acting as a proxy, but just not - doing any of the things that Privoxy would - normally be expected to do. It is still a middle-man in - the interaction between your browser and web sites. + No, this just means all optional filtering and actions are disabled. + Privoxy is still acting as a proxy, but just + doing less of the things that Privoxy would + normally be expected to do. It is still a middle-man in + the interaction between your browser and web sites. See below to bypass + the proxy. + +How can I tell Privoxy to totally ignore certain sites? + + Bypassing a proxy, or proxying based on arbitrary criteria, is purely a browser + configuration issue, not a &my-app; issue. Modern browsers typically do have + settings for not proxying certain sites. Check your browser's help files. + + + + -My logs show <application>Privoxy</application> <quote>crunches</quote> -ads, but also its own CGI pages. What is a <quote>crunch</quote>? +My logs show Privoxy <quote>crunches</quote> +ads, but also its own internal CGI pages. What is a <quote>crunch</quote>? - A crunch simply means Privoxy intercepted + A crunch simply means Privoxy intercepted something, nothing more. Often this is indeed ads or banners, but Privoxy uses the same mechanism for trapping requests for its own internal pages. For instance, a request for @@ -1669,23 +2074,27 @@ ads, but also its own CGI pages. What is a crunch? configuration is returned to the browser, and the log consequently will show a crunch. + + Since version 3.0.7, Privoxy will also log the crunch reason. + If you are using an older version you might want to upgrade. + -Can <application>Privoxy</application> effect files that I download +<title>Can Privoxy effect files that I download from a webserver? FTP server? From the webserver's perspective, there is no difference between viewing a document (i.e. a page), and downloading a file. The same is true of Privoxy. If there is a match for a block pattern, - it will still be blocked, and of course this is obvious. + it will still be blocked, and of course this is obvious. Filtering is potentially more of a concern since the results are not always so obvious, and the effects of filtering are there whether the file is simply viewed, or downloaded. And potentially whether the content is some obnoxious - advertizement, or Mr. Jimmy's latest/greatest source code jewel. Of course, + advertisement, or Mr. Jimmy's latest/greatest source code jewel. Of course, one of these presumably is bad content that we don't want, and the other is good content that we do want. Privoxy is blind to the differences, and can only @@ -1694,7 +2103,7 @@ from a webserver? FTP server? Privoxy knows the differences in files according - to the Document Type as reported by the webserver. If this is + to the Content Type as reported by the webserver. If this is reported accurately (e.g. application/zip for a zip archive), then Privoxy knows to ignore these where appropriate. Privoxy potentially can filter HTML @@ -1706,16 +2115,16 @@ from a webserver? FTP server? altered by filtering, will be saved too, for these (probably rare) cases. - Note that versions later than 3.0.2 do NOT filter document types of + Note that versions later than 3.0.2 do NOT filter document types reported as text/plain. Prior to this, Privoxy did filter this document type. - In short, filtering is ON if a) the Document Type as reported + In short, filtering is ON if a) the content type as reported by the webserver is appropriate and b) the configuration allows it (or at least does not disallow it). That's it. There is no magic cookie anywhere to say this is good and this is - bad. It's the configuration that let's it all happen or not. + bad. It's the configuration that lets it all happen or not. If you download text files, you probably do not want these to be filtered, @@ -1728,22 +2137,49 @@ from a webserver? FTP server? all to the content is to be avoided. - Privoxy does not do FTP at all, only HTTP - protocols, so please don't even try. + Privoxy does not do FTP at all, only HTTP + and HTTPS (SSL) protocols. -I just downloaded a Perl script, and <application>Privoxy</application> +<title>I just downloaded a Perl script, and Privoxy altered it! Yikes, what is wrong! Please read above. + +Should I continue to use a <quote>HOSTS</quote> file for ad-blocking? + + One time-tested technique to defeat common ads is to trick the local DNS + system by giving a phony IP address for the ad generator in the local + HOSTS file, typically using 127.0.0.1, aka + localhost. This effectively blocks the ad. + + + There is no reason to use this technique in conjunction with + Privoxy. Privoxy + does essentially the same thing, much more elegantly and with much more + flexibility. A large HOSTS file, in fact, not only + duplicates effort, but may get in the way and seriously slow down your system. + It is recommended to remove such entries from your HOSTS file. If you think + your hosts list is neglected by Privoxy's + configuration, consider adding your list to your user.action file: + + + + { +block } + www.ad.example1.com + ad.example2.com + ads.galore.example.com + etc.example.com + + -Where can I find more information about <application>Privoxy</application> +<title>Where can I find more information about Privoxy and related issues? &seealso; @@ -1751,15 +2187,15 @@ and related issues? -I've noticed that Privoxy changes <quote>Microsoft</quote> to +<title>I've noticed that Privoxy changes <quote>Microsoft</quote> to <quote>MicroSuck</quote>! Why are you manipulating my browsing? @@ -1768,11 +2204,59 @@ and related issues? activated the fun filter which is clearly labeled Text replacements for subversive browsing fun! or you are using an older Privoxy version and have implicitly - activated it by choosing the Adventuresome profile in the - web-based editor. + activated it by choosing the Advanced profile in the + web-based editor. Please upgrade. + + + + +Does Privoxy produce <quote>valid</quote> HTML (or XHTML)? + + + Privoxy generates HTML in both its own templates, and possibly + whenever there are text substitutions via a &my-app; filter. While this + should always conform to the HTML 4.01 specifications, it has not been + validated against this or any other standard. + + + + +How did you manage to get Privoxy on my computer without my consent? + + + We didn't. We make Privoxy available for download, but we don't go + around installing it on other people's systems behind their back. + If you discover Privoxy running on your system and are sure you didn't + install it yourself, somebody else did. You may not even be running + the real Privoxy, but maybe something else that only pretends to be + Privoxy, or maybe something that is based on the real Privoxy, + but has been modified. + + + Lately there have been reports of problems with some kind of + Privoxy versions that come preinstalled on some Netbooks. + Some of the problems described are inconsistent with the behaviour + of official Privoxy versions, which suggests that the preinstalled + software may contain vendor modifications that we don't know about + and thus can't debug. + + + Privoxy's license allows vendor + modifications, but the vendor has to comply with the license, + which involves informing the user about the changes and to make + the changes available under the same license as Privoxy itself. + + + If you are having trouble with a modified Privoxy version, + please try to talk to whoever made the modifications before + reporting the problem to us. Please also try to convince + whoever made the modifications to talk to us. If you think + somebody gave you a modified Privoxy version without complying + to the license, please let us know. + @@ -1782,37 +2266,55 @@ and related issues? Troubleshooting -I am getting <quote>connection refused</quote> -with every web page? +I cannot connect to any websites. Or, I am getting +<quote>connection refused</quote> message with every web page. Why? - Either Privoxy is not running, or your - browser is configured for a different port than what - Privoxy is using. + There are several possibilities: - - Early Privoxy versions (and also - 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 the listen-address - option in Privoxy's main configuration file. + + +Privoxy is not running. Solution: verify + that &my-app; is installed correctly, has not crashed, and is indeed running. + Turn on Privoxy's logging, and look at the logs to see what they say. + + Or your browser is configured for a different port than what + Privoxy is using. Solution: verify that &my-app; + and your browser are set to the same port (listen-address). + + Or if using a forwarding rule, you have a configuration problem or a + problem with a host in the forwarding chain. Solution: temporarily alter your + configuration and take the forwarders out of the equation. + + + Or you have a firewall that is interfering and blocking you. Solution: + try disabling or removing the firewall as a simple test. + + + + +Why am I getting a 503 Error (WSAECONNREFUSED) on every page? + + More than likely this is a problem with your TCP/IP networking. ZoneAlarm has + been reported to cause this symptom -- even if not running! The solution is + to either fight the ZA configuration, or uninstall ZoneAlarm, and then find + something better behaved in its place. Other personal firewall type products + may cause similar type problems if not configured correctly. + + + -I just added a new rule, but the steenkin ad is +<title id="flushit">I just added a new rule, but the steenkin ad is still getting through. How? If the ad had been displayed before you added its URL, it will probably be held in the browser's cache for some time, so it will be displayed without the need for any request to the server, and Privoxy - will not be in the picture. The best thing to do is try flushing the browser's - caches. And then try again. + will not be involved. Flush the browser's caches, and then try again. @@ -1820,33 +2322,105 @@ still getting through. How? applied. Try pasting the full URL of the offending ad into http://config.privoxy.org/show-url-info and see if it really matches your new rule. Blocking ads is like blocking - spam: a lot of tinkering is required to stay ahead of the game. + spam: a lot of tinkering is required to stay ahead of the game. And + remember you need to block the URL of the ad in question, which may be + entirely different from the site URL itself. Most ads are hosted on different + servers than the main site itself. If you right-click on the ad, you should + be able to get all the relevant information you need. Alternately, you can + find the correct URL by looking at Privoxy's logs + (you may need to enable logging in the main config file if its disabled). + + + Below is a slightly modified real-life log snippet that originates with one + requested URL: www.example.com (name of site was changed + for this example, the number of requests is real). You can see in this the + complexity of what goes into making up this one page. There + are eight different domains involved here, with thirty two separate URLs + requested in all, making up all manner of images, Shockwave Flash, + JavaScript, CSS stylesheets, scripts, and other related content. Some of this + content is obviously good or bad, but not all. + Many of the more questionable looking requests, are going to outside domains + that seem to be identifying themselves with suspicious looking names, making + our job a little easier. &my-app; has crunched (meaning caught + and BLOCKED) quite a few items in this example, but perhaps missed a few as well. + + + + + + + + Despite 12 out of 32 requests being blocked, the page looked, and seemed to + behave perfectly normal (minus some ads, of course). -One of my favorite sites does not work with <application>Privoxy</application>. +<title >One of my favorite sites does not work with Privoxy. What can I do? - First verify that it is indeed a Privoxy problem, + First verify that it is indeed a Privoxy problem, by toggling off Privoxy through http://config.privoxy.org/toggle, + url="http://config.privoxy.org/toggle">http://config.privoxy.org/toggle + (the toggle feature may need to be enabled in the main + config), and then shift-reloading the problem page (i.e. holding down the shift key while clicking reload. Alternatively, flush your browser's disk and memory caches). - If still a problem, go to http://config.privoxy.org/show-url-info - and paste the full URL of the page in question into the prompt. See which actions - are being applied to the URL, and which matches in which actions files are - responsible for that. Now, armed with this information, go to required. + Now, armed with this information, go to + http://config.privoxy.org/show-status - and select the appropriate actions files for editing. - + and select the appropriate actions files for editing. You can now either look for a section which disables the actions that you suspect to cause the problem and add a pattern for your site there, @@ -1857,19 +2431,25 @@ What can I do? on again. Remember to flush your browser's caches in between any such changes! - Alternately, if you are comfortable with a text editor, you can accomplish - the same thing by editing the appropriate actions file. Probably the easiest + Alternately, if you are comfortable with a text editor, you can accomplish + the same thing by editing the appropriate actions file. Probably the easiest way to deal with such problems when editing by hand is to add your site to a { fragile } section in user.action, which is an alias that turns off most dangerous actions, but is also likely to turn off more actions then needed, and thus lower - your privacy and protection more than necessary, + your privacy and protection more than necessary, Troubleshooting actions is discussed in more detail in the user-manual appendix. + url="../user-manual/appendix.html#ACTIONSANAT">User Manual appendix, + Troubleshooting: the Anatomy of an Action. There is also an actions tutorial. + url="../user-manual/actions-file.html#ACT-EXAMPLES">actions tutorial + with general configuration information and examples. + + + As a last resort, you can always see if your browser has a setting that will + bypass the proxy setting for selective sites. Modern browsers can do this. @@ -1877,7 +2457,7 @@ What can I do? -After installing <application>Privoxy</application>, I have to log in +<title>After installing Privoxy, I have to log in every time I start IE. What gives? @@ -1915,7 +2495,7 @@ every time I start IE. What gives? set-up DUN connection and each LAN connection in IE store the settings for each user individually. As such this enforces individual configurations rather than common ones. Hence the first time you use a DUN connection after - re-booting your system it may not perform as you expect, and prompt you for + re-booting your system it may not perform as you expect, and prompt you for the password. Just set and save the password again and all should be OK. @@ -1927,27 +2507,30 @@ every time I start IE. What gives? -I cannot connect to any FTP sites. <application>Privoxy</application> - seems to be blocking me. +I cannot connect to any FTP sites. Privoxy + is blocking me. - Privoxy cannot act as a proxy for FTP traffic, + Privoxy cannot act as a proxy for FTP traffic, so do not configure your browser to use Privoxy as an FTP proxy. The same is true for any protocol other than HTTP - or HTTPS. + or HTTPS (SSL). Most browsers understand FTP as well as HTTP. If you connect to a site, with a URL like ftp://ftp.example.com, your browser is making - an FTP connection, and not a HTTP connection. So while your browser may - speak FTP, Privoxy does not, and cannot proxy + an FTP connection, and not a HTTP connection. So while your browser may + speak FTP, Privoxy does not, and cannot proxy such traffic. To complicate matters, some systems may have a generic proxy - setting, which will silently enable both HTTP and FTP - proxying! So it is possible to accidentally enable FTP proxying in these - cases. And of course, if this happens, Privoxy - will indeed cause problems since it does not know FTP. + setting, which will enable various protocols, including + both HTTP and FTP proxying! So it is possible to + accidentally enable FTP proxying in these cases. And of course, if this + happens, Privoxy will indeed cause problems since + it does not know FTP. Just disable the FTP setting + and all will be well again. Will Privoxy ever proxy FTP traffic? Unlikely. @@ -1957,58 +2540,62 @@ every time I start IE. What gives? - -In Mac OSX, I can't configure Microsoft Internet Explorer to use - <application>Privoxy</application> as the HTTP proxy. + +In Mac OS X, I can't configure Microsoft Internet Explorer to use + Privoxy as the HTTP proxy. Microsoft Internet Explorer (in versions like 5.1) respects system-wide network settings. In order to change the HTTP proxy, open System Preferences, and click on the Network icon. In the settings pane that - comes up, click on the Proxies tab. Ensure the "Web Proxy (HTTP)" checkbox - is checked and enter 127.0.0.1 in the entry field. + comes up, click on the Proxies tab. Ensure the "Web Proxy (HTTP)" checkbox + is checked and enter 127.0.0.1 in the entry field. Enter 8118 in the Port field. The next time you start IE, it should reflect these values. - -In Mac OSX, I dragged the Privoxy folder to the trash in order to - uninstall it. Now the finder tells me I don't have sufficient privileges to +<sect2 renderas="sect3" id="macosxuninstall"> +<title>In Mac OS X, I dragged the Privoxy folder to the trash in order to + uninstall it. Now the finder tells me I don't have sufficient privileges to empty the trash. + + Note: This ONLY applies to privoxy 3.0.6 and earlier. + Just dragging the Privoxy folder to the trash is - not enough to delete it. Privoxy supplies an + not enough to delete it. Privoxy supplies an uninstall.command file that takes care of - these details. Open the trash, drag the uninstall.command - file out of the trash and double-click on it. You will be prompted for + these details. Open the trash, drag the uninstall.command + file out of the trash and double-click on it. You will be prompted for confirmation and the administration password. - + - The trash may still appear full after this command; emptying the trash + The trash may still appear full after this command; emptying the trash from the desktop should make it appear empty again. - -In Mac OSX Panther (10.3), images often fail to load and/or I +<sect2 renderas="sect3" id="macosximages"> +<title>In Mac OS X Panther (10.3), images often fail to load and/or I experience random delays in page loading. I'm using <literal>localhost</literal> as my browser's proxy setting. - We believe this is due to an IPv6-related bug in OSX, but don't fully - understand the issue yet. In any case, changing the proxy setting to + We believe this is due to an IPv6-related bug in Mac OS X, but don't fully + understand the issue yet. In any case, changing the proxy setting to 127.0.0.1 instead of localhost works around the problem. + I get a completely blank page at one site. <quote>View Source</quote> shows only: <markup><![CDATA[<html><body></body></html>]]></markup>. Without - <application>Privoxy</application> the page loads fine. + Privoxy the page loads fine. Chances are that the site suffers from a bug in PHP, @@ -2022,9 +2609,9 @@ every time I start IE. What gives? user.action: - # Make exceptions for ill-behaved sites: - # - {-prevent-compression} + # Make exceptions for ill-behaved sites: + # + {-prevent-compression} .example.com If that works, you may also want to report the problem to the @@ -2034,18 +2621,6 @@ every time I start IE. What gives? - - -Why am I getting a 503 Error (WSAECONNREFUSED) on every page? - - More than likely this is a problem with your TCP/IP networking. ZoneAlarm has - been reported to cause this symptom -- even if not running. The solution is - to either fight the ZA configuration, or uninstall ZoneAlarm, and then find - something better behaved in its place. Other personal firewall type products - may cause similar type problems if not configured correctly. - - - My logs show many <quote>Unable to get my own hostname</quote> lines. Why? @@ -2054,7 +2629,7 @@ Why? its running on from the IP address of the system interface it is bound to (from the config file listen-address setting). If the system cannot supply - this information, Privoxy logs this condition. + this information, Privoxy logs this condition. Typically, this would be considered a minor system configuration error. It is @@ -2062,21 +2637,31 @@ Why? result in a much slower response from Privoxy on some platforms due to DNS timeouts. + + This can be caused by a problem with the local hosts + file. If this file has been changed from the original, try reverting it to + see if that helps. Make sure whatever name(s) are used for the local system, + that they resolve both ways. + + + You should also be able to work around the problem with the + hostname option. + -When I try to launch <application>Privoxy</application>, I get an +<title>When I try to launch Privoxy, I get an error message <quote>port 8118 is already in use</quote> (or similar wording). Why? - Port 8118 is Privoxy's default TCP + Port 8118 is Privoxy's default TCP listening port. Typically this message would mean that there is already one instance of Privoxy running, and - you are actually trying to start a second Privoxy - on the same port, which will not work. (You can have multiple instances but - they must be assigned different ports.) How and why this might happen varies - from platform to platform, but you need to check your installation and - start-up procedures. + your system is actually trying to start a second + Privoxy on the same port, which will not work. + (You can have multiple instances but they must be assigned different ports.) + How and why this might happen varies from platform to platform, but you need + to check your installation and start-up procedures. @@ -2095,12 +2680,12 @@ Why? - Why are binary files (such as images) corrupted when <application>Privoxy</application> + Why are binary files (such as images) corrupted when Privoxy is used? - This may also be caused by the demoronizer filter, - in conjunction with a web server that is misreporting a file type. Binary + This may also be caused by the demoronizer filter, + in conjunction with a web server that is misreporting the content type. Binary files are exempted from Privoxy's filtering (unless the web server by mistake says the file is something else). Either upgrade Privoxy, or go to the most recent @@ -2114,27 +2699,27 @@ Why? What is the demoronizer and why is it there? - The original demoronizer was a Perl script that cleaned up HTML pages which - were created with certain Microsoft products. MS has used proprietary extensions + The original demoronizer was a Perl script that cleaned up HTML pages which + were created with certain Microsoft products. MS has used proprietary extensions to standardized font encodings (ISO 8859-1), which has caused problems for pages that are viewed with non-Microsoft products (and are expecting to see a standard set of fonts). The demoronizer corrected these errors so the pages displayed correctly. Privoxy borrowed from this script, introducing a filter based on the original demoronizer, which in turn could - correct these errors on the fly. + correct these errors on the fly. - But this is only needed in some situations, and will cause serious problems in some + But this is only needed in some situations, and will cause serious problems in some other situations. - If you are using Microsoft products, you do not need it. If you need to view - pages with UTF-8 characters (such as Cyrillic or Chinese), then it will + If you are using Microsoft products, you do not need it. If you need to view + pages with UTF-8 characters (such as Cyrillic or Chinese), then it will cause corruption of the fonts, and thus should not be on. - On the other hand, if you use non-Microsoft products, and you occasionally - notice wierd characters on pages, you might want to try it. + On the other hand, if you use non-Microsoft products, and you occasionally + notice weird characters on pages, you might want to try it. @@ -2143,15 +2728,16 @@ Why? Why do I keep seeing PrivoxyWindowOpen() in raw source code? - Privoxy is attempting to disable malicious - Javascript in this case, with the unsolicited-popups - filter. Privoxy cannot tell very well + Privoxy is attempting to disable malicious + Javascript + in this case, with the unsolicited-popups + filter. Privoxy cannot tell very well good code snippets from bad code snippets. - If you see this in HTML source, and the page displays without problems, then - this is good, and likely some pop-up window was disabled. If you see this - where it is causing a problem, such as a downloaded program source code file, + If you see this in HTML source, and the page displays without problems, then + this is good, and likely some pop-up window was disabled. If you see this + where it is causing a problem, such as a downloaded program source code file, then you should set an exception for this site or page such that the integrity of the page stays in tact by disabling all filtering. @@ -2160,49 +2746,173 @@ Why? I am getting too many DNS errors like <quote>404 No Such Domain</quote>. Why - can't <application>Privoxy</application> do this better? + can't Privoxy do this better? There are potentially several factors here. First of all, the DNS resolution is done by the underlying operating system -- not Privoxy itself. Privoxy merely initiates the process and hands it off, and then later reports - whatever the outcome was. And tries to give a coherent message if there seems + whatever the outcome was and tries to give a coherent message if there seems to be a problem. In some cases, this might otherwise be mitigated by the - browser itself which might try some work-arounds and alernate approaches (e.g - adding www. to the URL). In other cases, if - Privoxy is being chained with another proxy, this - could complicate the issue, and cause undue + browser itself which might try some work-arounds and alternate approaches (e.g + adding www. to the URL). + + + In other cases, if Privoxy is being chained + with another proxy, this could complicate the issue, and cause undue delays and timeouts. In the case of a socks4a proxy, the socks server handles all the DNS. Privoxy would just be the messenger which is reporting whatever problem occurred downstream, and not the root cause of the error. + - In any case, v. 3.0.4 includes various improvements to help + In any case, versions newer than 3.0.3 include various improvements to help Privoxy better handle these cases. - +]]> - At one site <application>Privoxy</application> just hangs, and starts taking + At one site Privoxy just hangs, and starts taking all CPU. Why is this? This is probably a manifestation of the 100% cpu problem that - occurs on pages containing many (thousands upon thousands) of blank lines. The blank lines - are in the raw HTML source of the page, and the browser just ignores them. But the + occurs on pages containing many (thousands upon thousands) of blank lines. The blank lines + are in the raw HTML source of the page, and the browser just ignores them. But the pattern matching in Privoxy's page filtering mechanism is trying to match against absurdly long strings and this becomes - very CPU-intensive, taking a long, long time to complete. Until a better - solution comes along, disable filtering on these pages, particularly the - js-annoyances and unsolicited-popups - filters. + very CPU-intensive, taking a long, long time to complete. + + + Until a better solution comes along, disable filtering on these pages, + particularly the js-annoyances and + unsolicited-popups filters. If you run into this problem + with a recent &my-app; version, please send a problem report. + + + + +I just installed Privoxy, and all my +browsing has slowed to a crawl. What gives? + + This should not happen, and for the overwhelming number of users world-wide, + it does not happen. I would suspect some inadvertent interaction of software + components such as anti-virus software, spyware protectors, personal + firewalls or similar components. Try disabling (or uninstalling) these one + at a time and see if that helps. Either way, if you are using a + recent &my-app; version, please report the problem. + + + + +Why do my filters work on some sites but not on others? + + It's probably due to compression. It is a common practice for web servers to + send their content compressed in order to speed things up, and + then let the browser uncompress them. When compiled with zlib support + &my-app; can decompress content before filtering, otherwise you may want to enable +prevent-compression. + + + As of &my-app; 3.0.9, zlib support is enabled in the default builds. + +On some HTTPS sites my browser warns me about unauthenticated content, + the URL bar doesn't get highlighted and the lock symbol appears to be broken. + What's going on? + + Probably the browser is requesting ads through HTTPS and &my-app; + is blocking the requests. Privoxy's error messages are delivered + unencrypted and while it's obvious for the browser that the HTTPS + request is already blocked by the proxy, some warn about unauthenticated + content anyway. + + + To work around the problem you can redirect those requests to an invalid + local address instead of blocking them. While the redirects aren't + encrypted either, many browsers don't care. They simply follow the + redirect, fail to reach a server and display an error message instead + of the ad. + + + To do that, enable logging to figure out which requests get blocked by + &my-app; and add the hosts (no path patterns) to a section like this: + + + + + + + + Additionally you have to configure your browser to contact + 127.0.0.1:0 directly (instead of through &my-app;). + + + To add a proxy exception in Mozilla Firefox + open the Preferences, click the Settings + button located on the Network tab in the Advanced + section, and add 127.0.0.1:0 in the No Proxy for: + field. + + + + + +I get selinux error messages. How can I fix this? + + Please report the problem to the creator of your selinux policies. + + + The problem is that some selinux policy writers aren't familiar + with the application they are trying to secure and + thus create policies that make no sense. + + + In Privoxy's case the problem usually + is that the policy only allows outgoing connections for certain + destination ports (e.g. 80 and 443). While this may cover the + standard ports, websites occasionally use other ports as well. + This isn't a security problem and therefore Privoxy's + default configuration doesn't block these requests. + + + If you really want to block these ports (and don't be able + to load websites that don't use standard ports), you should + configure Privoxy to block these ports as well, so it doesn't + trigger the selinux warnings. + + + + + +I compiled &my-app; with Gentoo's portage and it appears to be very slow. Why? + + Probably you unintentionally compiled &my-app; without threading support + in which case requests have to be serialized and only one can be served + at the same time. + + + Check your USE flags and make sure they include + threads. If they don't, add the flag and rebuild &my-app;. + + + If you compiled &my-app; with threading support (on POSIX-based systems), + the Conditional #defines section on http://config.privoxy.org/show-status + will list FEATURE_PTHREAD as enabled. + + + @@ -2212,18 +2922,18 @@ Why? &contacting; - + Privoxy Copyright, License and History ©right; - + Portions of this document are borrowed from the original - Junkbuster (tm) FAQ, and modified as + Junkbuster (tm) FAQ, and modified as appropriate for Privoxy. @@ -2244,8 +2954,8 @@ Why? - - + +