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53 <h1 class="SECT1"><a name="CONFIGURATION" id="CONFIGURATION">3.
54 Configuration</a></h1>
57 <h3 class="SECT2"><a name="AEN369" id="AEN369">3.1. What exactly is an
58 <span class="QUOTE">"actions"</span> file?</a></h3>
60 <p><span class="APPLICATION">Privoxy</span> utilizes the concept of
61 <span class="QUOTE">" <a href=
62 "../user-manual/actions-file.html#ACTIONS" target=
63 "_top">actions</a>"</span> that are used to manipulate and control web
64 page data. <a href="../user-manual/actions-file.html" target=
65 "_top">Actions files</a> are where these <a href=
66 "../user-manual/actions-file.html#ACTIONS" target="_top">actions</a>
67 that <span class="APPLICATION">Privoxy</span> could take while
68 processing a certain request, are configured. Typically, you would
69 define a set of default actions that apply globally to all URLs, then
70 add exceptions to these defaults where needed. There is a wide array of
71 actions available that give the user a high degree of control and
72 flexibility on how to process each and every web page.</p>
74 <p>Actions can be defined on a <a href=
75 "../user-manual/actions-file.html#AF-PATTERNS" target="_top">URL
76 pattern</a> basis, i.e. for single URLs, whole web sites, groups or
77 parts thereof etc. Actions can also be grouped together and then
78 applied to requests matching one or more patterns. There are many
79 possible actions that might apply to any given site. As an example, if
80 you are blocking <a href="http://en.wikipedia.org/wiki/Browser_cookie"
81 target="_top">cookies</a> as one of your default actions, but need to
82 accept cookies from a given site, you would need to define an exception
83 for this site in one of your actions files, preferably in <tt class=
84 "FILENAME">user.action</tt>.</p>
88 <h3 class="SECT2"><a name="ACTIONSS" id="ACTIONSS">3.2. The
89 <span class="QUOTE">"actions"</span> concept confuses me. Please list
90 some of these <span class="QUOTE">"actions"</span>.</a></h3>
92 <p>For a comprehensive discussion of the actions concept, please refer
93 to the <a href="../user-manual/actions-file.html" target="_top">actions
94 file chapter</a> in the <a href="../user-manual/index.html" target=
95 "_top">User Manual</a>. It includes a <a href=
96 "../user-manual/actions-file.html#ACTIONS" target="_top">list of all
97 actions</a> and an <a href=
98 "../user-manual/actions-file.html#ACT-EXAMPLES" target="_top">actions
99 file tutorial</a> to get you started.</p>
103 <h3 class="SECT2"><a name="AEN392" id="AEN392">3.3. How are actions
104 files configured? What is the easiest way to do this?</a></h3>
106 <p>Actions files are just text files in a special syntax and can be
107 edited with a text editor. But probably the easiest way is to access
108 <span class="APPLICATION">Privoxy</span>'s user interface with your web
109 browser at <a href="http://config.privoxy.org/" target=
110 "_top">http://config.privoxy.org/</a> (Shortcut: <a href="http://p.p/"
111 target="_top">http://p.p/</a>) and then select <span class=
112 "QUOTE">"<a href="http://config.privoxy.org/show-status" target=
113 "_top">View & change the current configuration</a>"</span> from the
114 menu. Note that this feature must be explicitly enabled in the main
115 config file (see <a href=
116 "../user-manual/config.html#ENABLE-EDIT-ACTIONS" target=
117 "_top">enable-edit-actions</a>).</p>
121 <h3 class="SECT2"><a name="AEN401" id="AEN401">3.4. There are several
122 different <span class="QUOTE">"actions"</span> files. What are the
123 differences?</a></h3>
125 <p>Please have a look at the <a href="../user-manual/actions-file.html"
126 target="_top">the actions chapter</a> in the <a href=
127 "../user-manual/index.html" target="_top">User Manual</a> for a
128 detailed explanation.</p>
132 <h3 class="SECT2"><a name="GETUPDATES" id="GETUPDATES">3.5. Where can I
133 get updated Actions Files?</a></h3>
135 <p>Based on your feedback and the continuing development, updates of
136 <tt class="FILENAME">default.action</tt> will be made available from
137 time to time on the <a href=
138 "http://sourceforge.net/project/showfiles.php?group_id=11118" target=
139 "_top">files section</a> of our <a href=
140 "http://sf.net/projects/ijbswa/" target="_top">project page</a>.</p>
142 <p>If you wish to receive an email notification whenever we release
143 updates of <span class="APPLICATION">Privoxy</span> or the actions
145 "http://lists.sourceforge.net/lists/listinfo/ijbswa-announce/" target=
146 "_top">subscribe to our announce mailing list</a>,
147 ijbswa-announce@lists.sourceforge.net.</p>
151 <h3 class="SECT2"><a name="NEWCONFIG" id="NEWCONFIG">3.6. Can I use my
152 old config files?</a></h3>
154 <p>The syntax and purpose of configuration files has remained roughly
155 the same throughout the 3.x series, but backwards compatibility is not
156 guaranteed. Also each release contains updated, <span class=
157 "QUOTE">"improved"</span> versions and it is therefore strongly
158 recommended to install the newer configuration files and merge back
159 your modifications.</p>
163 <h3 class="SECT2"><a name="DIFFICULT" id="DIFFICULT">3.7. Why is the
164 configuration so complicated?</a></h3>
166 <p><span class="QUOTE">"Complicated"</span> is in the eye of the
167 beholder. Those that are familiar with some of the underlying concepts,
168 such as regular expression syntax, take to it like a fish takes to
169 water. Also, software that tries hard to be <span class="QUOTE">"user
170 friendly"</span>, often lacks sophistication and flexibility. There is
171 always that trade-off there between power vs. easy-of-use. Furthermore,
172 anyone is welcome to contribute ideas and implementations to enhance
173 <span class="APPLICATION">Privoxy</span>.</p>
177 <h3 class="SECT2"><a name="YAHOO" id="YAHOO">3.8. How can I make my
178 Yahoo/Hotmail/Gmail account work?</a></h3>
180 <p>The default configuration shouldn't impact the usability of any of
181 these services. It may, however, make all <a href=
182 "http://en.wikipedia.org/wiki/Browser_cookie" target="_top">cookies</a>
183 temporary, so that your browser will forget your login credentials in
184 between browser sessions. If you would like not to have to log in
185 manually each time you access those websites, simply turn off all
186 cookie handling for them in the <tt class="FILENAME">user.action</tt>
187 file. An example for yahoo might look like:</p>
189 <table class="c2" border="0" width="100%">
193 # Allow all cookies for Yahoo login:
195 { -<a href="../user-manual/actions-file.html#CRUNCH-INCOMING-COOKIES" target=
196 "_top">crunch-incoming-cookies</a> -<a href=
197 "../user-manual/actions-file.html#CRUNCH-OUTGOING-COOKIES" target=
198 "_top">crunch-outgoing-cookies</a> -<a href=
199 "../user-manual/actions-file.html#SESSION-COOKIES-ONLY" target=
200 "_top">session-cookies-only</a> }
207 <p>These kinds of sites are often quite complex and heavy with <a href=
208 "http://en.wikipedia.org/wiki/Javascript" target="_top">Javascript</a>
209 and thus <span class="QUOTE">"fragile"</span>. So if <span class=
210 "emphasis EMPHASIS c3">still</span> a problem, we have an <a href=
211 "../user-manual/actions-file.html#ALIASES" target="_top">alias</a> just
212 for such sticky situations:</p>
214 <table class="c2" border="0" width="100%">
218 # Gmail is a _fragile_ site:
220 { <tt class="LITERAL">fragile</tt> }
228 <p>Be sure to flush your browser's caches whenever making these kinds
229 of changes, just to make sure the changes <span class=
230 "QUOTE">"take"</span>.</p>
232 <p>Make sure the domain, host and path are appropriate as well. Your
233 browser can tell you where you are specifically and you should use that
234 information for your configuration settings. Note that above it is not
235 referenced as <tt class="LITERAL">gmail.com</tt>, which is a valid
240 <h3 class="SECT2"><a name="CONFIGFILES" id="CONFIGFILES">3.9. What's
241 the difference between the <span class="QUOTE">"Cautious"</span>,
242 <span class="QUOTE">"Medium"</span> and <span class=
243 "QUOTE">"Advanced"</span> defaults?</a></h3>
245 <p>Configuring <span class="APPLICATION">Privoxy</span> is not entirely
246 trivial. To help you get started, we provide you with three different
247 default action <span class="QUOTE">"profiles"</span> in the web based
248 actions file editor at <a href="http://config.privoxy.org/show-status"
249 target="_top">http://config.privoxy.org/show-status</a>. See the
250 <a class="CITETITLE c4" href="../user-manual/actions-file.html" target=
251 "_top">User Manual</a> for a list of actions, and how the default
252 profiles are set.</p>
254 <p>Where the defaults are likely to break some sites, exceptions for
255 known popular <span class="QUOTE">"problem"</span> sites are included,
256 but in general, the more aggressive your default settings are, the more
257 exceptions you will have to make later. New users are best to start off
258 in <span class="QUOTE">"Cautious"</span> setting. This is safest and
259 will have the fewest problems. See the <a class="CITETITLE c4" href=
260 "../user-manual/index.html" target="_top">User Manual</a> for a more
261 detailed discussion.</p>
263 <p>It should be noted that the <span class="QUOTE">"Advanced"</span>
264 profile (formerly known as the <span class=
265 "QUOTE">"Adventuresome"</span> profile) is more aggressive, and will
266 make use of some of <span class="APPLICATION">Privoxy's</span> advanced
267 features. Use at your own risk!</p>
271 <h3 class="SECT2"><a name="BROWSECONFIG" id="BROWSECONFIG">3.10. Why
272 can I change the configuration with a browser? Does that not raise
273 security issues?</a></h3>
275 <p>It may seem strange that regular users can edit the config files
276 with their browsers, although the whole <tt class=
277 "FILENAME">/etc/privoxy</tt> hierarchy belongs to the user <span class=
278 "QUOTE">"privoxy"</span>, with only 644 permissions.</p>
280 <p>When you use the browser-based editor, <span class=
281 "APPLICATION">Privoxy</span> itself is writing to the config files.
282 Because <span class="APPLICATION">Privoxy</span> is running as the user
283 <span class="QUOTE">"privoxy"</span>, it can update its own config
286 <p>If you run <span class="APPLICATION">Privoxy</span> for multiple
287 untrusted users (e.g. in a LAN) or aren't entirely in control of your
288 own browser, you will probably want to make sure that the web-based
289 editor and remote toggle features are <span class="QUOTE">"off"</span>
290 by setting <span class="QUOTE">"<tt class="LITERAL"><a href=
291 "../user-manual/config.html#ENABLE-EDIT-ACTIONS" target=
292 "_top">enable-edit-actions</a> 0</tt>"</span> and <span class=
293 "QUOTE">"<tt class="LITERAL"><a href=
294 "../user-manual/config.html#ENABLE-REMOTE-TOGGLE" target=
295 "_top">enable-remote-toggle</a> 0</tt>"</span> in the <a href=
296 "../user-manual/config.html" target="_top">main configuration
299 <p>As of <span class="APPLICATION">Privoxy</span> 3.0.7 these options
300 are disabled by default.</p>
304 <h3 class="SECT2"><a name="AEN489" id="AEN489">3.11. What is the
305 <tt class="FILENAME">default.filter</tt> file? What is a <span class=
306 "QUOTE">"filter"</span>?</a></h3>
308 <p>The <a href="../user-manual/filter-file.html" target=
309 "_top"><tt class="FILENAME">default.filter</tt></a> file is where
310 <span class="emphasis EMPHASIS c3">filters</span> as supplied by the
311 developers are defined. Filters are a special subset of actions that
312 can be used to modify or remove web page content or headers on the fly.
313 Content filters can be applied to <span class=
314 "emphasis EMPHASIS c3">anything</span> in the page source, header
315 filters can be applied to either server or client headers. Regular
316 expressions are used to accomplish this.</p>
318 <p>There are a number of pre-defined filters to deal with common
319 annoyances. The filters are only defined here, to invoke them, you need
320 to use the <a href="../user-manual/actions-file.html#FILTER" target=
321 "_top"><tt class="LITERAL">filter</tt> action</a> in one of the actions
322 files. Content filtering is automatically disabled for inappropriate
323 MIME types, but if you know better than Privoxy what should or should
324 not be filtered you can filter any content you like.</p>
326 <p>Filters should <span class="emphasis EMPHASIS c3">not</span> be
327 confused with <a href="../user-manual/actions-file.html#BLOCK" target=
328 "_top"><tt class="LITERAL">blocks</tt></a>, which is a completely
329 different action, and is more typically used to block ads and unwanted
332 <p>If you are familiar with regular expressions, and HTML, you can look
333 at the provided <tt class="FILENAME">default.filter</tt> with a text
334 editor and define your own filters. This is potentially a very powerful
335 feature, but requires some expertise in both regular expressions and
336 HTML/HTTP. You should place any modifications to the default filters,
337 or any new ones you create in a separate file, such as <tt class=
338 "FILENAME">user.filter</tt>, so they won't be overwritten during
339 upgrades. The ability to define multiple filter files in <tt class=
340 "FILENAME">config</tt> is a new feature as of v. 3.0.5.</p>
342 <p>There is no GUI editor option for this part of the configuration,
343 but you can disable/enable the various pre-defined filters of the
344 included <tt class="FILENAME">default.filter</tt> file with the
345 <a href="http://config.privoxy.org/show-status" target="_top">web-based
346 actions file editor</a>. Note that the custom actions editor must be
347 explicitly enabled in the main config file (see <a href=
348 "../user-manual/config.html#ENABLE-EDIT-ACTIONS" target=
349 "_top">enable-edit-actions</a>).</p>
351 <p>If you intend to develop your own filters, you might want to have a
352 look at <a href="http://www.fabiankeil.de/sourcecode/pft/" target=
353 "_top">Privoxy-Filter-Test</a>.</p>
357 <h3 class="SECT2"><a name="LANCONFIG" id="LANCONFIG">3.12. How can I
358 set up Privoxy to act as a proxy for my LAN?</a></h3>
360 <p>By default, <span class="APPLICATION">Privoxy</span> only responds
361 to requests from <tt class="LITERAL">127.0.0.1</tt> (localhost). To
362 have it act as a server for a network, this needs to be changed in the
363 <a href="../user-manual/config.html" target="_top">main configuration
364 file</a>. Look for the <tt class="LITERAL"><a href=
365 "../user-manual/config.html#LISTEN-ADDRESS" target=
366 "_top">listen-address</a></tt> option, which may be commented out with
367 a <span class="QUOTE">"#"</span> symbol. Make sure it is uncommented,
368 and assign it the address of the LAN gateway interface, and port number
369 to use. Assuming your LAN address is 192.168.1.1 and you wish to run
370 <span class="APPLICATION">Privoxy</span> on port 8118, this line should
373 <table class="c2" border="0" width="100%">
377 listen-address 192.168.1.1:8118
383 <p>Save the file, and restart <span class="APPLICATION">Privoxy</span>.
384 Configure all browsers on the network then to use this address and port
387 <p>Alternately, you can have <span class="APPLICATION">Privoxy</span>
388 listen on all available interfaces:</p>
390 <table class="c2" border="0" width="100%">
400 <p>And then use <span class="APPLICATION">Privoxy's</span> <a href=
401 "../user-manual/config.html#PERMIT-ACCESS" target=
402 "_top">permit-access</a> feature to limit connections. A firewall in
403 this situation is recommended as well.</p>
405 <p>The above steps should be the same for any TCP network, regardless
406 of operating system.</p>
408 <p>If you run <span class="APPLICATION">Privoxy</span> on a LAN with
409 untrusted users, we recommend that you double-check the <a href=
410 "../user-manual/config.html#ACCESS-CONTROL" target="_top">access
411 control and security</a> options!</p>
415 <h3 class="SECT2"><a name="AEN540" id="AEN540">3.13. Instead of ads,
416 now I get a checkerboard pattern. I don't want to see
419 <p>The replacement for blocked images can be controlled with the
420 <a href="../user-manual/actions-file.html#SET-IMAGE-BLOCKER" target=
421 "_top"><tt class="LITERAL">set-image-blocker</tt> action</a>. You have
422 the choice of a checkerboard pattern, a transparent 1x1 GIF image (aka
423 <span class="QUOTE">"blank"</span>), or a redirect to a custom image of
424 your choice. Note that this choice only has effect for images which are
425 blocked as images, i.e. whose URLs match both a <tt class=
426 "LITERAL"><a href="../user-manual/actions-file.html#HANDLE-AS-IMAGE"
427 target="_top">handle-as-image</a></tt> <span class=
428 "emphasis EMPHASIS c3">and</span> <tt class="LITERAL"><a href=
429 "../user-manual/actions-file.html#BLOCK" target="_top">block</a></tt>
432 <p>If you want to see nothing, then change the <a href=
433 "../user-manual/actions-file.html#SET-IMAGE-BLOCKER" target=
434 "_top"><tt class="LITERAL">set-image-blocker</tt> action</a> to
435 <span class="QUOTE">"blank"</span>. This can be done by editing the
436 <tt class="FILENAME">user.action</tt> file, or through the <a href=
437 "http://config.privoxy.org/show-status" target="_top">web-based actions
442 <h3 class="SECT2"><a name="AEN557" id="AEN557">3.14. Why would anybody
443 want to see a checkerboard pattern?</a></h3>
445 <p>Remember that <a href="general.html#WHATSANAD">telling which image
446 is an ad and which isn't</a>, is an educated guess. While we hope that
447 the standard configuration is rather smart, it will make occasional
448 mistakes. The checkerboard image is visually decent, and it shows you
449 where images have been blocked, which can be very helpful in case some
450 navigation aid or otherwise innocent image was erroneously blocked. It
451 is recommended for new users so they can <span class=
452 "QUOTE">"see"</span> what is happening. Some people might also enjoy
453 seeing how many banners they <span class=
454 "emphasis EMPHASIS c3">don't</span> have to see.</p>
458 <h3 class="SECT2"><a name="AEN563" id="AEN563">3.15. I see some images
459 being replaced with text instead of the checkerboard image. Why and how
460 do I get rid of this?</a></h3>
462 <p>This happens when the banners are not embedded in the HTML code of
463 the page itself, but in separate HTML (sub)documents that are loaded
464 into (i)frames or (i)layers, and these external HTML documents are
465 blocked. Being non-images they get replaced by a substitute HTML page
466 rather than a substitute image, which wouldn't work out technically,
467 since the browser expects and accepts only HTML when it has requested
468 an HTML document.</p>
470 <p>The substitute page adapts to the available space and shows itself
471 as a miniature two-liner if loaded into small frames, or full-blown
472 with a large red "BLOCKED" banner if space allows.</p>
474 <p>If you prefer the banners to be blocked by images, you must see to
475 it that the HTML documents in which they are embedded are not blocked.
476 Clicking the <span class="QUOTE">"See why"</span> link offered in the
477 substitute page will show you which rule blocked the page. After
478 changing the rule and un-blocking the HTML documents, the browser will
479 try to load the actual banner images and the usual image blocking will
480 (hopefully!) kick in.</p>
484 <h3 class="SECT2"><a name="SRVANY" id="SRVANY">3.16. Can Privoxy run as
485 a service on Win2K/NT/XP?</a></h3>
487 <p>Yes. Version 3.0.5 introduces full <span class=
488 "APPLICATION">Windows</span> service functionality. See <a href=
489 "../user-manual/installation.html#installation-pack-win" target=
490 "_top">the <i class="CITETITLE">User Manual</i></a> for details on how
491 to install and configure <span class="APPLICATION">Privoxy</span> as a
494 <p>Earlier 3.x versions could run as a system service using <b class=
495 "COMMAND">srvany.exe</b>. See the discussion at <a href=
496 "http://sourceforge.net/tracker/?func=detail&atid=361118&aid=485617&group_id=11118"
498 "_top">http://sourceforge.net/tracker/?func=detail&atid=361118&aid=485617&group_id=11118</a>,
499 for details, and a sample configuration.</p>
503 <h3 class="SECT2"><a name="OTHERPROXY" id="OTHERPROXY">3.17. How can I
504 make Privoxy work with other proxies?</a></h3>
506 <p>This can be done and is often useful to combine the benefits of
507 <span class="APPLICATION">Privoxy</span> with those of a another proxy,
508 for example to cache content. See the <a href=
509 "../user-manual/config.html#FORWARDING" target="_top">forwarding
510 chapter</a> in the <a href="../user-manual/index.html" target=
511 "_top">User Manual</a> which describes how to do this. If you intend to
512 use Privoxy with Tor, please also have a look at <a href=
513 "misc.html#TOR">How do I use Privoxy together with Tor</a>.</p>
517 <h3 class="SECT2"><a name="PORT-80" id="PORT-80">3.18. Can I just set
518 Privoxy to use port 80 and thus avoid individual browser
519 configuration?</a></h3>
521 <p>No, its more complicated than that. This only works with special
522 kinds of proxies known as <span class="QUOTE">"intercepting"</span>
523 proxies (<a href="configuration.html#INTERCEPTING">see below</a>).</p>
527 <h3 class="SECT2"><a name="TRANSPARENT" id="TRANSPARENT">3.19. Can
528 Privoxy run as a <span class="QUOTE">"transparent"</span>
531 <p>The whole idea of Privoxy is to modify client requests and server
532 responses in all sorts of ways and therefore it's not a transparent
533 proxy as described in <a href="http://tools.ietf.org/html/rfc2616"
534 target="_top">RFC 2616</a>.</p>
536 <p>However, some people say <span class="QUOTE">"transparent
537 proxy"</span> when they mean <span class="QUOTE">"intercepting
538 proxy"</span>. If you are one of them, please read the <a href=
539 "configuration.html#INTERCEPTING">next entry</a>.</p>
543 <h3 class="SECT2"><a name="INTERCEPTING" id="INTERCEPTING">3.20. Can
544 Privoxy run as a <span class="QUOTE">"intercepting"</span>
547 <p><span class="APPLICATION">Privoxy</span> can't intercept traffic
548 itself, but it can handle requests that where intercepted and
549 redirected with a packet filter (like <span class=
550 "APPLICATION">PF</span> or <span class="APPLICATION">iptables</span>),
551 as long as the <tt class="LITERAL">Host</tt> header is present.</p>
553 <p>As the <tt class="LITERAL">Host</tt> header is required by HTTP/1.1
554 and as most web sites rely on it anyway, this limitation shouldn't be a
557 <p>Please refer to your packet filter's documentation to learn how to
558 intercept and redirect traffic into <span class=
559 "APPLICATION">Privoxy</span>. Afterward you just have to configure
560 <span class="APPLICATION">Privoxy</span> to <a href=
561 "../user-manual/config.html#ACCEPT-INTERCEPTED-REQUESTS" target=
562 "_top">accept intercepted requests</a>.</p>
566 <h3 class="SECT2"><a name="OUTLOOK" id="OUTLOOK">3.21. How can I
567 configure Privoxy for use with Outlook?</a></h3>
569 <p>Versions of <span class="APPLICATION">Outlook</span> prior to Office
570 2007, use <span class="APPLICATION">Internet Explorer</span> components
571 to both render HTML, and fetch any HTTP requests that may be embedded
572 in an HTML email. So however you have <span class=
573 "APPLICATION">Privoxy</span> configured to work with IE, this
574 configuration should automatically be shared, at least with older
575 version of Internet Explorer.</p>
577 <p>Starting with Office 2007, Microsoft is instead using the MS-Word
578 rendering engine with Outlook. It is unknown whether this can be
579 configured to use a proxy.</p>
583 <h3 class="SECT2"><a name="OUTLOOK-MORE" id="OUTLOOK-MORE">3.22. How
584 can I have separate rules just for HTML mail?</a></h3>
586 <p>The short answer is, you can't. <span class=
587 "APPLICATION">Privoxy</span> has no way of knowing which particular
588 application makes a request, so there is no way to distinguish between
589 web pages and HTML mail. <span class="APPLICATION">Privoxy</span> just
590 blindly proxies all requests. In the case of <span class=
591 "APPLICATION">Outlook Express</span> (see above), OE uses IE anyway,
592 and there is no way for <span class="APPLICATION">Privoxy</span> to
593 ever be able to distinguish between them (nor could any other proxy
594 type application for that matter).</p>
596 <p>For a good discussion of some of the issues involved (including
597 privacy and security issues), see <a href=
598 "http://sourceforge.net/tracker/?func=detail&atid=211118&aid=629518&group_id=11118"
600 "_top">http://sourceforge.net/tracker/?func=detail&atid=211118&aid=629518&group_id=11118</a>.</p>
604 <h3 class="SECT2"><a name="SNEAKY-COOKIES" id="SNEAKY-COOKIES">3.23. I
605 sometimes notice cookies sneaking through. How?</a></h3>
607 <p><a href="http://en.wikipedia.org/wiki/Browser_cookie" target=
608 "_top">Cookies</a> can be set in several ways. The classic method is
609 via the <tt class="LITERAL">Set-Cookie</tt> HTTP header. This is
610 straightforward, and an easy one to manipulate, such as the
611 <span class="APPLICATION">Privoxy</span> concept of <a href=
612 "../user-manual/actions-file.html#SESSION-COOKIES-ONLY" target=
613 "_top">session-cookies-only</a>. There is also the possibility of using
614 <a href="http://en.wikipedia.org/wiki/Javascript" target=
615 "_top">Javascript</a> to set cookies (<span class=
616 "APPLICATION">Privoxy</span> calls these <tt class=
617 "LITERAL">content-cookies</tt>). This is trickier because the syntax
618 can vary widely, and thus requires a certain amount of guesswork. It is
619 not realistic to catch all of these short of disabling Javascript,
620 which would break many sites. And lastly, if the cookies are embedded
621 in a HTTPS/SSL secure session via Javascript, they are beyond
622 <span class="APPLICATION">Privoxy's</span> reach.</p>
624 <p>All in all, <span class="APPLICATION">Privoxy</span> can help manage
625 cookies in general, can help minimize the loss of privacy posed by
626 cookies, but can't realistically stop all cookies.</p>
630 <h3 class="SECT2"><a name="EVIL-COOKIES" id="EVIL-COOKIES">3.24. Are
631 all cookies bad? Why?</a></h3>
633 <p>No, in fact there are many beneficial uses of <a href=
634 "http://en.wikipedia.org/wiki/Browser_cookie" target=
635 "_top">cookies</a>. Cookies are just a method that browsers can use to
636 store data between pages, or between browser sessions. Sometimes there
637 is a good reason for this, and the user's life is a bit easier as a
638 result. But there is a long history of some websites taking advantage
639 of this layer of trust, and using the data they glean from you and your
640 browsing habits for their own purposes, and maybe to your potential
641 detriment. Such sites are using you and storing their data on your
642 system. That is why the privacy conscious watch from whom those cookies
643 come, and why they really <span class=
644 "emphasis EMPHASIS c3">need</span> to be there.</p>
646 <p>See the <a href="http://en.wikipedia.org/wiki/Browser_cookie"
647 target="_top">Wikipedia cookie definition</a> for more.</p>
651 <h3 class="SECT2"><a name="ALLOW-COOKIES" id="ALLOW-COOKIES">3.25. How
652 can I allow permanent cookies for my trusted sites?</a></h3>
654 <p>There are several actions that relate to cookies. The default
655 behavior is to allow only <span class="QUOTE">"session cookies"</span>,
656 which means the cookies only last for the current browser session. This
657 eliminates most kinds of abuse related to cookies. But there may be
658 cases where you want cookies to last.</p>
660 <p>To disable all cookie actions, so that cookies are allowed
661 unrestricted, both in and out, for <tt class=
662 "LITERAL">example.com</tt>:</p>
664 <table class="c2" border="0" width="100%">
668 { -crunch-incoming-cookies -crunch-outgoing-cookies -session-cookies-only -filter{content-cookies} }
675 <p>Place the above in <tt class="FILENAME">user.action</tt>. Note that
676 some of these may be off by default anyway, so this might be redundant,
677 but there is no harm being explicit in what you want to happen.
678 <tt class="FILENAME">user.action</tt> includes an alias for this
679 situation, called <tt class="LITERAL">allow-all-cookies</tt>.</p>
683 <h3 class="SECT2"><a name="MULTIPLES" id="MULTIPLES">3.26. Can I have
684 separate configurations for different users?</a></h3>
686 <p>Each instance of <span class="APPLICATION">Privoxy</span> has its
687 own configuration, including such attributes as the TCP port that it
688 listens on. What you can do is run multiple instances of <span class=
689 "APPLICATION">Privoxy</span>, each with a unique <a href=
690 "../user-manual/config.html#LISTEN-ADDRESS" target=
691 "_top">listen-address</a> configuration setting, and configuration
692 path, and then each of these can have their own configurations. Think
693 of it as per-port configuration.</p>
695 <p>Simple enough for a few users, but for large installations, consider
696 having groups of users that might share like configurations.</p>
700 <h3 class="SECT2"><a name="WHITELISTS" id="WHITELISTS">3.27. Can I
701 set-up Privoxy as a whitelist of <span class="QUOTE">"good"</span>
704 <p>Sure. There are a couple of things you can do for simple
705 white-listing. Here's one real easy one:</p>
707 <table class="c2" border="0" width="100%">
711 ############################################################
713 ############################################################
714 { <a href="../user-manual/actions-file.html#BLOCK" target=
718 ############################################################
720 ############################################################
721 { <a href="../user-manual/actions-file.html#BLOCK" target=
731 <p>This allows access to only those three sites by first blocking all
732 URLs, and then subsequently allowing three specific exceptions.</p>
734 <p>Another approach is <span class="APPLICATION">Privoxy's</span>
735 <tt class="LITERAL">trustfile</tt> concept, which incorporates the
736 notion of <span class="QUOTE">"trusted referrers"</span>. See the
737 <a href="../user-manual/config.html#TRUSTFILE" target="_top">Trust
738 documentation</a> for details.</p>
740 <p>These are fairly simple approaches and are not completely foolproof.
741 There are various other configuration options that should be disabled
742 (described elsewhere here and in <a href="../user-manual/" target=
743 "_top">the User Manual</a>) so that users can't modify their own
744 configuration and easily circumvent the whitelist.</p>
748 <h3 class="SECT2"><a name="NO-ADBLOCK" id="NO-ADBLOCK">3.28. How can I
749 turn off ad-blocking?</a></h3>
751 <p>Ad blocking is achieved through a complex application of various
752 <span class="APPLICATION">Privoxy</span> <a href=
753 "../user-manual/actions-file.html" target="_top">actions</a>. These
754 actions are deployed against simple images, banners, flash animations,
755 text pages, JavaScript, pop-ups and pop-unders, etc., so its not as
756 simple as just turning one or two actions off. The various actions that
757 make up <span class="APPLICATION">Privoxy</span> ad blocking are
758 hard-coded into the default configuration files. It has been assumed
759 that everyone using <span class="APPLICATION">Privoxy</span> is
760 interested in this particular feature.</p>
762 <p>If you want to do without this, there are several approaches you can
763 take: You can manually undo the many block rules in <tt class=
764 "FILENAME">default.action</tt>. Or even easier, just create your own
765 <tt class="FILENAME">default.action</tt> file from scratch without the
766 many ad blocking rules, and corresponding exceptions. Or lastly, if you
767 are not concerned about the additional blocks that are done for privacy
768 reasons, you can very easily over-ride <span class=
769 "emphasis EMPHASIS c3">all</span> blocking with the following very
770 simple rule in your <tt class="FILENAME">user.action</tt>:</p>
772 <table class="c2" border="0" width="100%">
776 # Unblock everybody, everywhere
777 { <a href="../user-manual/actions-file.html#BLOCK" target=
779 / # UN-Block *all* URLs
785 <p>Or even a more comprehensive reversing of various ad related
788 <table class="c2" border="0" width="100%">
792 # Unblock everybody, everywhere, and turn off appropriate filtering, etc
793 { <a href="../user-manual/actions-file.html#BLOCK" target=
795 <a href="../user-manual/actions-file.html#FILTER-BANNERS-BY-SIZE" target=
796 "_top">-filter{banners-by-size}</a> \
797 <a href="../user-manual/actions-file.html#FILTER-BANNERS-BY-LINK" target=
798 "_top">-filter{banners-by-link}</a> \
799 <tt class="LITERAL">allow-popups</tt> \
801 / # UN-Block *all* URLs and allow ads
807 <p>This last <span class="QUOTE">"action"</span> in this compound
808 statement, <tt class="LITERAL">allow-popups</tt>, is an <a href=
809 "../user-manual/actions-file.html#ALIASES" target="_top">alias</a> that
810 disables various pop-up blocking features.</p>
814 <h3 class="SECT2"><a name="TEMPLATES" id="TEMPLATES">3.29. How can I
815 have custom template pages, like the <span class=
816 "emphasis EMPHASIS c3">BLOCKED</span> page?</a></h3>
818 <p><span class="APPLICATION">Privoxy</span> <span class=
819 "QUOTE">"templates"</span> are specialized text files utilized by
820 <span class="APPLICATION">Privoxy</span> for various purposes and can
821 easily be modified using any text editor. All the template pages are
822 installed in a sub-directory appropriately named: <tt class=
823 "FILENAME">templates</tt>. Knowing something about HTML syntax will of
824 course be helpful.</p>
826 <p>Be forewarned that the default templates are subject to being
827 overwritten during upgrades. You can, however, create completely new
828 templates, place them in another directory and specify the alternate
829 path in the main <tt class="FILENAME">config</tt>. For details, have a
830 look at the <a href="../user-manual/config.html#templdir" target=
831 "_top">templdir</a> option.</p>
835 <h3 class="SECT2"><a name="BLOCKALL" id="BLOCKALL">3.30. How can I
836 remove the <span class="QUOTE">"Go There Anyway"</span> link from the
837 <span class="emphasis EMPHASIS c3">BLOCKED</span> page?</a></h3>
839 <p>There is more than one way to do it (although Perl is not
842 <p>Editing the BLOCKED template page (see above) may dissuade some
843 users, but this method is easily circumvented. Where you need this
844 level of control, you might want to build <span class=
845 "APPLICATION">Privoxy</span> from source, and disable various features
846 that are available as compile-time options. You should <b class=
847 "COMMAND">configure</b> the sources as follows:</p>
849 <table class="c2" border="0" width="100%">
853 ./configure --disable-toggle --disable-editor --disable-force
859 <p>This will create an executable with hard-coded security features so
860 that <span class="APPLICATION">Privoxy</span> does not allow easy
861 bypassing of blocked sites, or changing the current configuration via
862 any connected user's web browser.</p>
864 <p>Finally, all of these features can also be toggled on/off via
865 options in <span class="APPLICATION">Privoxy's</span> main <a href=
866 "../user-manual/config.html#ACCESS-CONTROL" target="_top">config</a>
867 file which means you don't have to recompile anything.</p>
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