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41 <h1 class="SECT1"><a name="CONFIGURATION" id="CONFIGURATION">3.
42 Configuration</a></h1>
45 <h3 class="SECT2"><a name="AEN359" id="AEN359">3.1. What exactly is an
46 <span class="QUOTE">"actions"</span> file?</a></h3>
48 <p><span class="APPLICATION">Privoxy</span> utilizes the concept of
49 <span class="QUOTE">" <a href=
50 "../user-manual/actions-file.html#ACTIONS" target=
51 "_top">actions</a>"</span> that are used to manipulate and control web
52 page data. <a href="../user-manual/actions-file.html" target=
53 "_top">Actions files</a> are where these <a href=
54 "../user-manual/actions-file.html#ACTIONS" target="_top">actions</a>
55 that <span class="APPLICATION">Privoxy</span> could take while
56 processing a certain request, are configured. Typically, you would
57 define a set of default actions that apply globally to all URLs, then
58 add exceptions to these defaults where needed. There is a wide array of
59 actions available that give the user a high degree of control and
60 flexibility on how to process each and every web page.</p>
62 <p>Actions can be defined on a <a href=
63 "../user-manual/actions-file.html#AF-PATTERNS" target="_top">URL
64 pattern</a> basis, i.e. for single URLs, whole web sites, groups or
65 parts thereof etc. Actions can also be grouped together and then
66 applied to requests matching one or more patterns. There are many
67 possible actions that might apply to any given site. As an example, if
68 you are blocking <a href="http://en.wikipedia.org/wiki/Browser_cookie"
69 target="_top">cookies</a> as one of your default actions, but need to
70 accept cookies from a given site, you would need to define an exception
71 for this site in one of your actions files, preferably in <tt class=
72 "FILENAME">user.action</tt>.</p>
76 <h3 class="SECT2"><a name="ACTIONSS" id="ACTIONSS">3.2. The
77 <span class="QUOTE">"actions"</span> concept confuses me. Please list
78 some of these <span class="QUOTE">"actions"</span>.</a></h3>
80 <p>For a comprehensive discussion of the actions concept, please refer
81 to the <a href="../user-manual/actions-file.html" target="_top">actions
82 file chapter</a> in the <a href="../user-manual/index.html" target=
83 "_top">User Manual</a>. It includes a <a href=
84 "../user-manual/actions-file.html#ACTIONS" target="_top">list of all
85 actions</a> and an <a href=
86 "../user-manual/actions-file.html#ACT-EXAMPLES" target="_top">actions
87 file tutorial</a> to get you started.</p>
91 <h3 class="SECT2"><a name="AEN382" id="AEN382">3.3. How are actions
92 files configured? What is the easiest way to do this?</a></h3>
94 <p>Actions files are just text files in a special syntax and can be
95 edited with a text editor. But probably the easiest way is to access
96 <span class="APPLICATION">Privoxy</span>'s user interface with your web
97 browser at <a href="http://config.privoxy.org/" target=
98 "_top">http://config.privoxy.org/</a> (Shortcut: <a href="http://p.p/"
99 target="_top">http://p.p/</a>) and then select <span class=
100 "QUOTE">"<a href="http://config.privoxy.org/show-status" target=
101 "_top">View & change the current configuration</a>"</span> from the
102 menu. Note that this feature must be explicitly enabled in the main
103 config file (see <a href=
104 "../user-manual/config.html#ENABLE-EDIT-ACTIONS" target=
105 "_top">enable-edit-actions</a>).</p>
109 <h3 class="SECT2"><a name="AEN391" id="AEN391">3.4. There are several
110 different <span class="QUOTE">"actions"</span> files. What are the
111 differences?</a></h3>
113 <p>Please have a look at the <a href="../user-manual/actions-file.html"
114 target="_top">the actions chapter</a> in the <a href=
115 "../user-manual/index.html" target="_top">User Manual</a> for a
116 detailed explanation.</p>
120 <h3 class="SECT2"><a name="GETUPDATES" id="GETUPDATES">3.5. Where can I
121 get updated Actions Files?</a></h3>
123 <p>Based on your feedback and the continuing development, updates of
124 <tt class="FILENAME">default.action</tt> will be made available from
125 time to time on the <a href=
126 "http://sourceforge.net/project/showfiles.php?group_id=11118" target=
127 "_top">files section</a> of our <a href=
128 "http://sf.net/projects/ijbswa/" target="_top">project page</a>.</p>
130 <p>If you wish to receive an email notification whenever we release
131 updates of <span class="APPLICATION">Privoxy</span> or the actions
133 "http://lists.sourceforge.net/lists/listinfo/ijbswa-announce/" target=
134 "_top">subscribe to our announce mailing list</a>,
135 ijbswa-announce@lists.sourceforge.net.</p>
139 <h3 class="SECT2"><a name="NEWCONFIG" id="NEWCONFIG">3.6. Can I use my
140 old config files?</a></h3>
142 <p>The syntax and purpose of configuration files has remained roughly
143 the same throughout the 3.x series, but backwards compatibility is not
144 guaranteed. Also each release contains updated, <span class=
145 "QUOTE">"improved"</span> versions and it is therefore strongly
146 recommended to install the newer configuration files and merge back
147 your modifications.</p>
151 <h3 class="SECT2"><a name="DIFFICULT" id="DIFFICULT">3.7. Why is the
152 configuration so complicated?</a></h3>
154 <p><span class="QUOTE">"Complicated"</span> is in the eye of the
157 <p>Privoxy is currently mainly written by and for people who are
158 already familiar with the underlying concepts like regular expressions,
159 HTTP and HTML, or are willing to become familiar with them to be able
160 to get the most out of a powerful and flexible tool such as
163 <p>While everybody is expected to be able to get a Privoxy default
164 installation up and running, fine-tuning requires a certain amount of
165 background information and Privoxy's documentation mainly concentrates
166 on the Privoxy-specific parts while only providing references to the
169 <p>If you or anyone you know has the skills, time and energy to reduce
170 the barrier of entry, please <a href="general.html#PARTICIPATE">get
175 <h3 class="SECT2"><a name="YAHOO" id="YAHOO">3.8. How can I make my
176 Yahoo/Hotmail/Gmail account work?</a></h3>
178 <p>The default configuration shouldn't impact the usability of any of
179 these services. It may, however, make all <a href=
180 "http://en.wikipedia.org/wiki/Browser_cookie" target="_top">cookies</a>
181 temporary, so that your browser will forget your login credentials in
182 between browser sessions. If you would like not to have to log in
183 manually each time you access those websites, simply turn off all
184 cookie handling for them in the <tt class="FILENAME">user.action</tt>
185 file. An example for yahoo might look like:</p>
187 <table border="0" bgcolor="#E0E0E0" width="100%">
191 # Allow all cookies for Yahoo login:
193 { -<a href="../user-manual/actions-file.html#CRUNCH-INCOMING-COOKIES" target=
194 "_top">crunch-incoming-cookies</a> -<a href=
195 "../user-manual/actions-file.html#CRUNCH-OUTGOING-COOKIES" target=
196 "_top">crunch-outgoing-cookies</a> -<a href=
197 "../user-manual/actions-file.html#SESSION-COOKIES-ONLY" target=
198 "_top">session-cookies-only</a> }
205 <p>These kinds of sites are often quite complex and heavy with <a href=
206 "http://en.wikipedia.org/wiki/Javascript" target="_top">Javascript</a>
207 and thus <span class="QUOTE">"fragile"</span>. So if <span class=
208 "emphasis"><i class="EMPHASIS">still</i></span> a problem, we have an
209 <a href="../user-manual/actions-file.html#ALIASES" target=
210 "_top">alias</a> just for such sticky situations:</p>
212 <table border="0" bgcolor="#E0E0E0" width="100%">
216 # Gmail is a _fragile_ site:
218 { <tt class="LITERAL">fragile</tt> }
226 <p>Be sure to flush your browser's caches whenever making these kinds
227 of changes, just to make sure the changes <span class=
228 "QUOTE">"take"</span>.</p>
230 <p>Make sure the domain, host and path are appropriate as well. Your
231 browser can tell you where you are specifically and you should use that
232 information for your configuration settings. Note that above it is not
233 referenced as <tt class="LITERAL">gmail.com</tt>, which is a valid
238 <h3 class="SECT2"><a name="CONFIGFILES" id="CONFIGFILES">3.9. What's
239 the difference between the <span class="QUOTE">"Cautious"</span>,
240 <span class="QUOTE">"Medium"</span> and <span class=
241 "QUOTE">"Advanced"</span> defaults?</a></h3>
243 <p>Configuring <span class="APPLICATION">Privoxy</span> is not entirely
244 trivial. To help you get started, we provide you with three different
245 default action <span class="QUOTE">"profiles"</span> in the web based
246 actions file editor at <a href="http://config.privoxy.org/show-status"
247 target="_top">http://config.privoxy.org/show-status</a>. See the
248 <a href="../user-manual/actions-file.html" target="_top"><i class=
249 "CITETITLE">User Manual</i></a> for a list of actions, and how the
250 default profiles are set.</p>
252 <p>Where the defaults are likely to break some sites, exceptions for
253 known popular <span class="QUOTE">"problem"</span> sites are included,
254 but in general, the more aggressive your default settings are, the more
255 exceptions you will have to make later. New users are best to start off
256 in <span class="QUOTE">"Cautious"</span> setting. This is safest and
257 will have the fewest problems. See the <a href=
258 "../user-manual/index.html" target="_top"><i class="CITETITLE">User
259 Manual</i></a> for a more detailed discussion.</p>
261 <p>It should be noted that the <span class="QUOTE">"Advanced"</span>
262 profile (formerly known as the <span class=
263 "QUOTE">"Adventuresome"</span> profile) is more aggressive, and will
264 make use of some of <span class="APPLICATION">Privoxy's</span> advanced
265 features. Use at your own risk!</p>
269 <h3 class="SECT2"><a name="BROWSECONFIG" id="BROWSECONFIG">3.10. Why
270 can I change the configuration with a browser? Does that not raise
271 security issues?</a></h3>
273 <p>It may seem strange that regular users can edit the config files
274 with their browsers, although the whole <tt class=
275 "FILENAME">/etc/privoxy</tt> hierarchy belongs to the user <span class=
276 "QUOTE">"privoxy"</span>, with only 644 permissions.</p>
278 <p>When you use the browser-based editor, <span class=
279 "APPLICATION">Privoxy</span> itself is writing to the config files.
280 Because <span class="APPLICATION">Privoxy</span> is running as the user
281 <span class="QUOTE">"privoxy"</span>, it can update its own config
284 <p>If you run <span class="APPLICATION">Privoxy</span> for multiple
285 untrusted users (e.g. in a LAN) or aren't entirely in control of your
286 own browser, you will probably want to make sure that the web-based
287 editor and remote toggle features are <span class="QUOTE">"off"</span>
288 by setting <span class="QUOTE">"<tt class="LITERAL"><a href=
289 "../user-manual/config.html#ENABLE-EDIT-ACTIONS" target=
290 "_top">enable-edit-actions</a> 0</tt>"</span> and <span class=
291 "QUOTE">"<tt class="LITERAL"><a href=
292 "../user-manual/config.html#ENABLE-REMOTE-TOGGLE" target=
293 "_top">enable-remote-toggle</a> 0</tt>"</span> in the <a href=
294 "../user-manual/config.html" target="_top">main configuration
297 <p>As of <span class="APPLICATION">Privoxy</span> 3.0.7 these options
298 are disabled by default.</p>
302 <h3 class="SECT2"><a name="AEN481" id="AEN481">3.11. What is the
303 <tt class="FILENAME">default.filter</tt> file? What is a <span class=
304 "QUOTE">"filter"</span>?</a></h3>
306 <p>The <a href="../user-manual/filter-file.html" target=
307 "_top"><tt class="FILENAME">default.filter</tt></a> file is where
308 <span class="emphasis"><i class="EMPHASIS">filters</i></span> as
309 supplied by the developers are defined. Filters are a special subset of
310 actions that can be used to modify or remove web page content or
311 headers on the fly. Content filters can be applied to <span class=
312 "emphasis"><i class="EMPHASIS">anything</i></span> in the page source,
313 header filters can be applied to either server or client headers.
314 Regular expressions are used to accomplish this.</p>
316 <p>There are a number of pre-defined filters to deal with common
317 annoyances. The filters are only defined here, to invoke them, you need
318 to use the <a href="../user-manual/actions-file.html#FILTER" target=
319 "_top"><tt class="LITERAL">filter</tt> action</a> in one of the actions
320 files. Content filtering is automatically disabled for inappropriate
321 MIME types, but if you know better than Privoxy what should or should
322 not be filtered you can filter any content you like.</p>
324 <p>Filters should <span class="emphasis"><i class=
325 "EMPHASIS">not</i></span> be confused with <a href=
326 "../user-manual/actions-file.html#BLOCK" target="_top"><tt class=
327 "LITERAL">blocks</tt></a>, which is a completely different action, and
328 is more typically used to block ads and unwanted sites.</p>
330 <p>If you are familiar with regular expressions, and HTML, you can look
331 at the provided <tt class="FILENAME">default.filter</tt> with a text
332 editor and define your own filters. This is potentially a very powerful
333 feature, but requires some expertise in both regular expressions and
334 HTML/HTTP. You should place any modifications to the default filters,
335 or any new ones you create in a separate file, such as <tt class=
336 "FILENAME">user.filter</tt>, so they won't be overwritten during
337 upgrades. The ability to define multiple filter files in <tt class=
338 "FILENAME">config</tt> is a new feature as of v. 3.0.5.</p>
340 <p>There is no GUI editor option for this part of the configuration,
341 but you can disable/enable the various pre-defined filters of the
342 included <tt class="FILENAME">default.filter</tt> file with the
343 <a href="http://config.privoxy.org/show-status" target="_top">web-based
344 actions file editor</a>. Note that the custom actions editor must be
345 explicitly enabled in the main config file (see <a href=
346 "../user-manual/config.html#ENABLE-EDIT-ACTIONS" target=
347 "_top">enable-edit-actions</a>).</p>
349 <p>If you intend to develop your own filters, you might want to have a
350 look at <a href="http://www.fabiankeil.de/sourcecode/pft/" target=
351 "_top">Privoxy-Filter-Test</a>.</p>
355 <h3 class="SECT2"><a name="LANCONFIG" id="LANCONFIG">3.12. How can I
356 set up Privoxy to act as a proxy for my LAN?</a></h3>
358 <p>By default, <span class="APPLICATION">Privoxy</span> only responds
359 to requests from <tt class="LITERAL">127.0.0.1</tt> (localhost). To
360 have it act as a server for a network, this needs to be changed in the
361 <a href="../user-manual/config.html" target="_top">main configuration
362 file</a>. Look for the <tt class="LITERAL"><a href=
363 "../user-manual/config.html#LISTEN-ADDRESS" target=
364 "_top">listen-address</a></tt> option, which may be commented out with
365 a <span class="QUOTE">"#"</span> symbol. Make sure it is uncommented,
366 and assign it the address of the LAN gateway interface, and port number
367 to use. Assuming your LAN address is 192.168.1.1 and you wish to run
368 <span class="APPLICATION">Privoxy</span> on port 8118, this line should
371 <table border="0" bgcolor="#E0E0E0" width="100%">
375 listen-address 192.168.1.1:8118
381 <p>Save the file, and restart <span class="APPLICATION">Privoxy</span>.
382 Configure all browsers on the network then to use this address and port
385 <p>Alternately, you can have <span class="APPLICATION">Privoxy</span>
386 listen on all available interfaces:</p>
388 <table border="0" bgcolor="#E0E0E0" width="100%">
398 <p>And then use <span class="APPLICATION">Privoxy's</span> <a href=
399 "../user-manual/config.html#PERMIT-ACCESS" target=
400 "_top">permit-access</a> feature to limit connections. A firewall in
401 this situation is recommended as well.</p>
403 <p>The above steps should be the same for any TCP network, regardless
404 of operating system.</p>
406 <p>If you run <span class="APPLICATION">Privoxy</span> on a LAN with
407 untrusted users, we recommend that you double-check the <a href=
408 "../user-manual/config.html#ACCESS-CONTROL" target="_top">access
409 control and security</a> options!</p>
413 <h3 class="SECT2"><a name="AEN532" id="AEN532">3.13. Instead of ads,
414 now I get a checkerboard pattern. I don't want to see
417 <p>The replacement for blocked images can be controlled with the
418 <a href="../user-manual/actions-file.html#SET-IMAGE-BLOCKER" target=
419 "_top"><tt class="LITERAL">set-image-blocker</tt> action</a>. You have
420 the choice of a checkerboard pattern, a transparent 1x1 GIF image (aka
421 <span class="QUOTE">"blank"</span>), or a redirect to a custom image of
422 your choice. Note that this choice only has effect for images which are
423 blocked as images, i.e. whose URLs match both a <tt class=
424 "LITERAL"><a href="../user-manual/actions-file.html#HANDLE-AS-IMAGE"
425 target="_top">handle-as-image</a></tt> <span class="emphasis"><i class=
426 "EMPHASIS">and</i></span> <tt class="LITERAL"><a href=
427 "../user-manual/actions-file.html#BLOCK" target="_top">block</a></tt>
430 <p>If you want to see nothing, then change the <a href=
431 "../user-manual/actions-file.html#SET-IMAGE-BLOCKER" target=
432 "_top"><tt class="LITERAL">set-image-blocker</tt> action</a> to
433 <span class="QUOTE">"blank"</span>. This can be done by editing the
434 <tt class="FILENAME">user.action</tt> file, or through the <a href=
435 "http://config.privoxy.org/show-status" target="_top">web-based actions
440 <h3 class="SECT2"><a name="AEN549" id="AEN549">3.14. Why would anybody
441 want to see a checkerboard pattern?</a></h3>
443 <p>Remember that <a href="general.html#WHATSANAD">telling which image
444 is an ad and which isn't</a>, is an educated guess. While we hope that
445 the standard configuration is rather smart, it will make occasional
446 mistakes. The checkerboard image is visually decent, and it shows you
447 where images have been blocked, which can be very helpful in case some
448 navigation aid or otherwise innocent image was erroneously blocked. It
449 is recommended for new users so they can <span class=
450 "QUOTE">"see"</span> what is happening. Some people might also enjoy
451 seeing how many banners they <span class="emphasis"><i class=
452 "EMPHASIS">don't</i></span> have to see.</p>
456 <h3 class="SECT2"><a name="AEN555" id="AEN555">3.15. I see some images
457 being replaced with text instead of the checkerboard image. Why and how
458 do I get rid of this?</a></h3>
460 <p>This happens when the banners are not embedded in the HTML code of
461 the page itself, but in separate HTML (sub)documents that are loaded
462 into (i)frames or (i)layers, and these external HTML documents are
463 blocked. Being non-images they get replaced by a substitute HTML page
464 rather than a substitute image, which wouldn't work out technically,
465 since the browser expects and accepts only HTML when it has requested
466 an HTML document.</p>
468 <p>The substitute page adapts to the available space and shows itself
469 as a miniature two-liner if loaded into small frames, or full-blown
470 with a large red "BLOCKED" banner if space allows.</p>
472 <p>If you prefer the banners to be blocked by images, you must see to
473 it that the HTML documents in which they are embedded are not blocked.
474 Clicking the <span class="QUOTE">"See why"</span> link offered in the
475 substitute page will show you which rule blocked the page. After
476 changing the rule and un-blocking the HTML documents, the browser will
477 try to load the actual banner images and the usual image blocking will
478 (hopefully!) kick in.</p>
482 <h3 class="SECT2"><a name="SRVANY" id="SRVANY">3.16. Can Privoxy run as
483 a service on Win2K/NT/XP?</a></h3>
485 <p>Yes. Version 3.0.5 introduces full <span class=
486 "APPLICATION">Windows</span> service functionality. See <a href=
487 "../user-manual/installation.html#installation-pack-win" target=
488 "_top">the <i class="CITETITLE">User Manual</i></a> for details on how
489 to install and configure <span class="APPLICATION">Privoxy</span> as a
492 <p>Earlier 3.x versions could run as a system service using <b class=
493 "COMMAND">srvany.exe</b>. See the discussion at <a href=
494 "http://sourceforge.net/tracker/?func=detail&atid=361118&aid=485617&group_id=11118"
496 "_top">http://sourceforge.net/tracker/?func=detail&atid=361118&aid=485617&group_id=11118</a>,
497 for details, and a sample configuration.</p>
501 <h3 class="SECT2"><a name="OTHERPROXY" id="OTHERPROXY">3.17. How can I
502 make Privoxy work with other proxies?</a></h3>
504 <p>This can be done and is often useful to combine the benefits of
505 <span class="APPLICATION">Privoxy</span> with those of a another proxy,
506 for example to cache content. See the <a href=
507 "../user-manual/config.html#FORWARDING" target="_top">forwarding
508 chapter</a> in the <a href="../user-manual/index.html" target=
509 "_top">User Manual</a> which describes how to do this. If you intend to
510 use Privoxy with Tor, please also have a look at <a href=
511 "misc.html#TOR">How do I use Privoxy together with Tor</a>.</p>
515 <h3 class="SECT2"><a name="PORT-80" id="PORT-80">3.18. Can I just set
516 Privoxy to use port 80 and thus avoid individual browser
517 configuration?</a></h3>
519 <p>No, its more complicated than that. This only works with special
520 kinds of proxies known as <span class="QUOTE">"intercepting"</span>
521 proxies (<a href="configuration.html#INTERCEPTING">see below</a>).</p>
525 <h3 class="SECT2"><a name="TRANSPARENT" id="TRANSPARENT">3.19. Can
526 Privoxy run as a <span class="QUOTE">"transparent"</span>
529 <p>The whole idea of Privoxy is to modify client requests and server
530 responses in all sorts of ways and therefore it's not a transparent
531 proxy as described in <a href="http://tools.ietf.org/html/rfc2616"
532 target="_top">RFC 2616</a>.</p>
534 <p>However, some people say <span class="QUOTE">"transparent
535 proxy"</span> when they mean <span class="QUOTE">"intercepting
536 proxy"</span>. If you are one of them, please read the <a href=
537 "configuration.html#INTERCEPTING">next entry</a>.</p>
541 <h3 class="SECT2"><a name="INTERCEPTING" id="INTERCEPTING">3.20. Can
542 Privoxy run as a <span class="QUOTE">"intercepting"</span>
545 <p><span class="APPLICATION">Privoxy</span> can't intercept traffic
546 itself, but it can handle requests that where intercepted and
547 redirected with a packet filter (like <span class=
548 "APPLICATION">PF</span> or <span class="APPLICATION">iptables</span>),
549 as long as the <tt class="LITERAL">Host</tt> header is present.</p>
551 <p>As the <tt class="LITERAL">Host</tt> header is required by HTTP/1.1
552 and as most web sites rely on it anyway, this limitation shouldn't be a
555 <p>Please refer to your packet filter's documentation to learn how to
556 intercept and redirect traffic into <span class=
557 "APPLICATION">Privoxy</span>. Afterward you just have to configure
558 <span class="APPLICATION">Privoxy</span> to <a href=
559 "../user-manual/config.html#ACCEPT-INTERCEPTED-REQUESTS" target=
560 "_top">accept intercepted requests</a>.</p>
564 <h3 class="SECT2"><a name="OUTLOOK" id="OUTLOOK">3.21. How can I
565 configure Privoxy for use with Outlook?</a></h3>
567 <p>Versions of <span class="APPLICATION">Outlook</span> prior to Office
568 2007, use <span class="APPLICATION">Internet Explorer</span> components
569 to both render HTML, and fetch any HTTP requests that may be embedded
570 in an HTML email. So however you have <span class=
571 "APPLICATION">Privoxy</span> configured to work with IE, this
572 configuration should automatically be shared, at least with older
573 version of Internet Explorer.</p>
575 <p>Starting with Office 2007, Microsoft is instead using the MS-Word
576 rendering engine with Outlook. It is unknown whether this can be
577 configured to use a proxy.</p>
581 <h3 class="SECT2"><a name="OUTLOOK-MORE" id="OUTLOOK-MORE">3.22. How
582 can I have separate rules just for HTML mail?</a></h3>
584 <p>The short answer is, you can't. <span class=
585 "APPLICATION">Privoxy</span> has no way of knowing which particular
586 application makes a request, so there is no way to distinguish between
587 web pages and HTML mail. <span class="APPLICATION">Privoxy</span> just
588 blindly proxies all requests. In the case of <span class=
589 "APPLICATION">Outlook Express</span> (see above), OE uses IE anyway,
590 and there is no way for <span class="APPLICATION">Privoxy</span> to
591 ever be able to distinguish between them (nor could any other proxy
592 type application for that matter).</p>
594 <p>For a good discussion of some of the issues involved (including
595 privacy and security issues), see <a href=
596 "http://sourceforge.net/tracker/?func=detail&atid=211118&aid=629518&group_id=11118"
598 "_top">http://sourceforge.net/tracker/?func=detail&atid=211118&aid=629518&group_id=11118</a>.</p>
602 <h3 class="SECT2"><a name="SNEAKY-COOKIES" id="SNEAKY-COOKIES">3.23. I
603 sometimes notice cookies sneaking through. How?</a></h3>
605 <p><a href="http://en.wikipedia.org/wiki/Browser_cookie" target=
606 "_top">Cookies</a> can be set in several ways. The classic method is
607 via the <tt class="LITERAL">Set-Cookie</tt> HTTP header. This is
608 straightforward, and an easy one to manipulate, such as the
609 <span class="APPLICATION">Privoxy</span> concept of <a href=
610 "../user-manual/actions-file.html#SESSION-COOKIES-ONLY" target=
611 "_top">session-cookies-only</a>. There is also the possibility of using
612 <a href="http://en.wikipedia.org/wiki/Javascript" target=
613 "_top">Javascript</a> to set cookies (<span class=
614 "APPLICATION">Privoxy</span> calls these <tt class=
615 "LITERAL">content-cookies</tt>). This is trickier because the syntax
616 can vary widely, and thus requires a certain amount of guesswork. It is
617 not realistic to catch all of these short of disabling Javascript,
618 which would break many sites. And lastly, if the cookies are embedded
619 in a HTTPS/SSL secure session via Javascript, they are beyond
620 <span class="APPLICATION">Privoxy's</span> reach.</p>
622 <p>All in all, <span class="APPLICATION">Privoxy</span> can help manage
623 cookies in general, can help minimize the loss of privacy posed by
624 cookies, but can't realistically stop all cookies.</p>
628 <h3 class="SECT2"><a name="EVIL-COOKIES" id="EVIL-COOKIES">3.24. Are
629 all cookies bad? Why?</a></h3>
631 <p>No, in fact there are many beneficial uses of <a href=
632 "http://en.wikipedia.org/wiki/Browser_cookie" target=
633 "_top">cookies</a>. Cookies are just a method that browsers can use to
634 store data between pages, or between browser sessions. Sometimes there
635 is a good reason for this, and the user's life is a bit easier as a
636 result. But there is a long history of some websites taking advantage
637 of this layer of trust, and using the data they glean from you and your
638 browsing habits for their own purposes, and maybe to your potential
639 detriment. Such sites are using you and storing their data on your
640 system. That is why the privacy conscious watch from whom those cookies
641 come, and why they really <span class="emphasis"><i class=
642 "EMPHASIS">need</i></span> to be there.</p>
644 <p>See the <a href="http://en.wikipedia.org/wiki/Browser_cookie"
645 target="_top">Wikipedia cookie definition</a> for more.</p>
649 <h3 class="SECT2"><a name="ALLOW-COOKIES" id="ALLOW-COOKIES">3.25. How
650 can I allow permanent cookies for my trusted sites?</a></h3>
652 <p>There are several actions that relate to cookies. The default
653 behavior is to allow only <span class="QUOTE">"session cookies"</span>,
654 which means the cookies only last for the current browser session. This
655 eliminates most kinds of abuse related to cookies. But there may be
656 cases where you want cookies to last.</p>
658 <p>To disable all cookie actions, so that cookies are allowed
659 unrestricted, both in and out, for <tt class=
660 "LITERAL">example.com</tt>:</p>
662 <table border="0" bgcolor="#E0E0E0" width="100%">
666 { -crunch-incoming-cookies -crunch-outgoing-cookies -session-cookies-only -filter{content-cookies} }
673 <p>Place the above in <tt class="FILENAME">user.action</tt>. Note that
674 some of these may be off by default anyway, so this might be redundant,
675 but there is no harm being explicit in what you want to happen.
676 <tt class="FILENAME">user.action</tt> includes an alias for this
677 situation, called <tt class="LITERAL">allow-all-cookies</tt>.</p>
681 <h3 class="SECT2"><a name="MULTIPLES" id="MULTIPLES">3.26. Can I have
682 separate configurations for different users?</a></h3>
684 <p>Each instance of <span class="APPLICATION">Privoxy</span> has its
685 own configuration, including such attributes as the TCP port that it
686 listens on. What you can do is run multiple instances of <span class=
687 "APPLICATION">Privoxy</span>, each with a unique <a href=
688 "../user-manual/config.html#LISTEN-ADDRESS" target=
689 "_top">listen-address</a> configuration setting, and configuration
690 path, and then each of these can have their own configurations. Think
691 of it as per-port configuration.</p>
693 <p>Simple enough for a few users, but for large installations, consider
694 having groups of users that might share like configurations.</p>
698 <h3 class="SECT2"><a name="WHITELISTS" id="WHITELISTS">3.27. Can I
699 set-up Privoxy as a whitelist of <span class="QUOTE">"good"</span>
702 <p>Sure. There are a couple of things you can do for simple
703 white-listing. Here's one real easy one:</p>
705 <table border="0" bgcolor="#E0E0E0" width="100%">
709 ############################################################
711 ############################################################
712 { <a href="../user-manual/actions-file.html#BLOCK" target=
716 ############################################################
718 ############################################################
719 { <a href="../user-manual/actions-file.html#BLOCK" target=
729 <p>This allows access to only those three sites by first blocking all
730 URLs, and then subsequently allowing three specific exceptions.</p>
732 <p>Another approach is <span class="APPLICATION">Privoxy's</span>
733 <tt class="LITERAL">trustfile</tt> concept, which incorporates the
734 notion of <span class="QUOTE">"trusted referrers"</span>. See the
735 <a href="../user-manual/config.html#TRUSTFILE" target="_top">Trust
736 documentation</a> for details.</p>
738 <p>These are fairly simple approaches and are not completely foolproof.
739 There are various other configuration options that should be disabled
740 (described elsewhere here and in <a href="../user-manual/" target=
741 "_top">the User Manual</a>) so that users can't modify their own
742 configuration and easily circumvent the whitelist.</p>
746 <h3 class="SECT2"><a name="NO-ADBLOCK" id="NO-ADBLOCK">3.28. How can I
747 turn off ad-blocking?</a></h3>
749 <p>Ad blocking is achieved through a complex application of various
750 <span class="APPLICATION">Privoxy</span> <a href=
751 "../user-manual/actions-file.html" target="_top">actions</a>. These
752 actions are deployed against simple images, banners, flash animations,
753 text pages, JavaScript, pop-ups and pop-unders, etc., so its not as
754 simple as just turning one or two actions off. The various actions that
755 make up <span class="APPLICATION">Privoxy</span> ad blocking are
756 hard-coded into the default configuration files. It has been assumed
757 that everyone using <span class="APPLICATION">Privoxy</span> is
758 interested in this particular feature.</p>
760 <p>If you want to do without this, there are several approaches you can
761 take: You can manually undo the many block rules in <tt class=
762 "FILENAME">default.action</tt>. Or even easier, just create your own
763 <tt class="FILENAME">default.action</tt> file from scratch without the
764 many ad blocking rules, and corresponding exceptions. Or lastly, if you
765 are not concerned about the additional blocks that are done for privacy
766 reasons, you can very easily over-ride <span class="emphasis"><i class=
767 "EMPHASIS">all</i></span> blocking with the following very simple rule
768 in your <tt class="FILENAME">user.action</tt>:</p>
770 <table border="0" bgcolor="#E0E0E0" width="100%">
774 # Unblock everybody, everywhere
775 { <a href="../user-manual/actions-file.html#BLOCK" target=
777 / # UN-Block *all* URLs
783 <p>Or even a more comprehensive reversing of various ad related
786 <table border="0" bgcolor="#E0E0E0" width="100%">
790 # Unblock everybody, everywhere, and turn off appropriate filtering, etc
791 { <a href="../user-manual/actions-file.html#BLOCK" target=
793 <a href="../user-manual/actions-file.html#FILTER-BANNERS-BY-SIZE" target=
794 "_top">-filter{banners-by-size}</a> \
795 <a href="../user-manual/actions-file.html#FILTER-BANNERS-BY-LINK" target=
796 "_top">-filter{banners-by-link}</a> \
797 <tt class="LITERAL">allow-popups</tt> \
799 / # UN-Block *all* URLs and allow ads
805 <p>This last <span class="QUOTE">"action"</span> in this compound
806 statement, <tt class="LITERAL">allow-popups</tt>, is an <a href=
807 "../user-manual/actions-file.html#ALIASES" target="_top">alias</a> that
808 disables various pop-up blocking features.</p>
812 <h3 class="SECT2"><a name="TEMPLATES" id="TEMPLATES">3.29. How can I
813 have custom template pages, like the <span class="emphasis"><i class=
814 "EMPHASIS">BLOCKED</i></span> page?</a></h3>
816 <p><span class="APPLICATION">Privoxy</span> <span class=
817 "QUOTE">"templates"</span> are specialized text files utilized by
818 <span class="APPLICATION">Privoxy</span> for various purposes and can
819 easily be modified using any text editor. All the template pages are
820 installed in a sub-directory appropriately named: <tt class=
821 "FILENAME">templates</tt>. Knowing something about HTML syntax will of
822 course be helpful.</p>
824 <p>Be forewarned that the default templates are subject to being
825 overwritten during upgrades. You can, however, create completely new
826 templates, place them in another directory and specify the alternate
827 path in the main <tt class="FILENAME">config</tt>. For details, have a
828 look at the <a href="../user-manual/config.html#templdir" target=
829 "_top">templdir</a> option.</p>
833 <h3 class="SECT2"><a name="BLOCKALL" id="BLOCKALL">3.30. How can I
834 remove the <span class="QUOTE">"Go There Anyway"</span> link from the
835 <span class="emphasis"><i class="EMPHASIS">BLOCKED</i></span>
838 <p>There is more than one way to do it (although Perl is not
841 <p>Editing the BLOCKED template page (see above) may dissuade some
842 users, but this method is easily circumvented. Where you need this
843 level of control, you might want to build <span class=
844 "APPLICATION">Privoxy</span> from source, and disable various features
845 that are available as compile-time options. You should <b class=
846 "COMMAND">configure</b> the sources as follows:</p>
848 <table border="0" bgcolor="#E0E0E0" width="100%">
852 ./configure --disable-toggle --disable-editor --disable-force
858 <p>This will create an executable with hard-coded security features so
859 that <span class="APPLICATION">Privoxy</span> does not allow easy
860 bypassing of blocked sites, or changing the current configuration via
861 any connected user's web browser.</p>
863 <p>Finally, all of these features can also be toggled on/off via
864 options in <span class="APPLICATION">Privoxy's</span> main <a href=
865 "../user-manual/config.html#ACCESS-CONTROL" target="_top">config</a>
866 file which means you don't have to recompile anything.</p>
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