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28 <h1 class="SECT1"><a name="CONFIGURATION" id="CONFIGURATION">3. Configuration</a></h1>
30 <h3 class="SECT2"><a name="ACTIONSFILE" id="ACTIONSFILE">3.1. What exactly is an <span class=
31 "QUOTE">"actions"</span> file?</a></h3>
32 <p><span class="APPLICATION">Privoxy</span> utilizes the concept of <span class="QUOTE">" <a href=
33 "../user-manual/actions-file.html#ACTIONS" target="_top">actions</a>"</span> that are used to manipulate and
34 control web page data. <a href="../user-manual/actions-file.html" target="_top">Actions files</a> are where these
35 <a href="../user-manual/actions-file.html#ACTIONS" target="_top">actions</a> that <span class=
36 "APPLICATION">Privoxy</span> could take while processing a certain request, are configured. Typically, you would
37 define a set of default actions that apply globally to all URLs, then add exceptions to these defaults where
38 needed. There is a wide array of actions available that give the user a high degree of control and flexibility on
39 how to process each and every web page.</p>
40 <p>Actions can be defined on a <a href="../user-manual/actions-file.html#AF-PATTERNS" target="_top">URL
41 pattern</a> basis, i.e. for single URLs, whole web sites, groups or parts thereof etc. Actions can also be
42 grouped together and then applied to requests matching one or more patterns. There are many possible actions that
43 might apply to any given site. As an example, if you are blocking <a href=
44 "http://en.wikipedia.org/wiki/Browser_cookie" target="_top">cookies</a> as one of your default actions, but need
45 to accept cookies from a given site, you would need to define an exception for this site in one of your actions
46 files, preferably in <tt class="FILENAME">user.action</tt>.</p>
49 <h3 class="SECT2"><a name="ACTIONSS" id="ACTIONSS">3.2. The <span class="QUOTE">"actions"</span> concept confuses
50 me. Please list some of these <span class="QUOTE">"actions"</span>.</a></h3>
51 <p>For a comprehensive discussion of the actions concept, please refer to the <a href=
52 "../user-manual/actions-file.html" target="_top">actions file chapter</a> in the <a href=
53 "../user-manual/index.html" target="_top">User Manual</a>. It includes a <a href=
54 "../user-manual/actions-file.html#ACTIONS" target="_top">list of all actions</a> and an <a href=
55 "../user-manual/actions-file.html#ACT-EXAMPLES" target="_top">actions file tutorial</a> to get you started.</p>
58 <h3 class="SECT2"><a name="ACTCONFIG" id="ACTCONFIG">3.3. How are actions files configured? What is the easiest
59 way to do this?</a></h3>
60 <p>Actions files are just text files in a special syntax and can be edited with a text editor. But probably the
61 easiest way is to access <span class="APPLICATION">Privoxy</span>'s user interface with your web browser at
62 <a href="http://config.privoxy.org/" target="_top">http://config.privoxy.org/</a> (Shortcut: <a href=
63 "http://p.p/" target="_top">http://p.p/</a>) and then select <span class="QUOTE">"<a href=
64 "http://config.privoxy.org/show-status" target="_top">View & change the current configuration</a>"</span>
65 from the menu. Note that this feature must be explicitly enabled in the main config file (see <a href=
66 "../user-manual/config.html#ENABLE-EDIT-ACTIONS" target="_top">enable-edit-actions</a>).</p>
69 <h3 class="SECT2"><a name="AEN413" id="AEN413">3.4. There are several different <span class=
70 "QUOTE">"actions"</span> files. What are the differences?</a></h3>
71 <p>Please have a look at the <a href="../user-manual/actions-file.html" target="_top">the actions chapter</a> in
72 the <a href="../user-manual/index.html" target="_top">User Manual</a> for a detailed explanation.</p>
75 <h3 class="SECT2"><a name="GETUPDATES" id="GETUPDATES">3.5. Where can I get updated Actions Files?</a></h3>
76 <p>Based on your feedback and the continuing development, updates of <tt class="FILENAME">default.action</tt>
77 will be made available from time to time on the <a href=
78 "https://sourceforge.net/project/showfiles.php?group_id=11118" target="_top">files section</a> of our <a href=
79 "https://sourceforge.net/projects/ijbswa/" target="_top">project page</a>.</p>
80 <p>If you wish to receive an email notification whenever we release updates of <span class=
81 "APPLICATION">Privoxy</span> or the actions file, <a href=
82 "https://lists.privoxy.org/mailman/listinfo/privoxy-announce" target="_top">subscribe to our announce mailing
83 list</a>, privoxy-announce@lists.privoxy.org.</p>
86 <h3 class="SECT2"><a name="NEWCONFIG" id="NEWCONFIG">3.6. Can I use my old config files?</a></h3>
87 <p>The syntax and purpose of configuration files has remained roughly the same throughout the 3.x series, but
88 backwards compatibility is not guaranteed. Also each release contains updated, <span class=
89 "QUOTE">"improved"</span> versions and it is therefore strongly recommended to install the newer configuration
90 files and merge back your modifications.</p>
93 <h3 class="SECT2"><a name="DIFFICULT" id="DIFFICULT">3.7. Why is the configuration so complicated?</a></h3>
94 <p><span class="QUOTE">"Complicated"</span> is in the eye of the beholder.</p>
95 <p>Privoxy is currently mainly written by and for people who are already familiar with the underlying concepts
96 like regular expressions, HTTP and HTML, or are willing to become familiar with them to be able to get the most
97 out of a powerful and flexible tool such as Privoxy.</p>
98 <p>While everybody is expected to be able to get a Privoxy default installation up and running, fine-tuning
99 requires a certain amount of background information and Privoxy's documentation mainly concentrates on the
100 Privoxy-specific parts while only providing references to the rest.</p>
101 <p>If you or anyone you know has the skills, time and energy to reduce the barrier of entry, please <a href=
102 "general.html#PARTICIPATE">get involved</a>.</p>
105 <h3 class="SECT2"><a name="YAHOO" id="YAHOO">3.8. How can I make my Yahoo/Hotmail/Gmail account work?</a></h3>
106 <p>The default configuration shouldn't impact the usability of any of these services. It may, however, make all
107 <a href="http://en.wikipedia.org/wiki/Browser_cookie" target="_top">cookies</a> temporary, so that your browser
108 will forget your login credentials in between browser sessions. If you would like not to have to log in manually
109 each time you access those websites, simply turn off all cookie handling for them in the <tt class=
110 "FILENAME">user.action</tt> file. An example for yahoo might look like:</p>
111 <table border="0" bgcolor="#E0E0E0" width="100%">
114 <pre class="SCREEN"># Allow all cookies for Yahoo login:
116 { -<a href="../user-manual/actions-file.html#CRUNCH-INCOMING-COOKIES" target=
117 "_top">crunch-incoming-cookies</a> -<a href="../user-manual/actions-file.html#CRUNCH-OUTGOING-COOKIES" target=
118 "_top">crunch-outgoing-cookies</a> -<a href="../user-manual/actions-file.html#SESSION-COOKIES-ONLY" target=
119 "_top">session-cookies-only</a> }
120 .login.yahoo.com</pre>
124 <p>These kinds of sites are often quite complex and heavy with <a href="http://en.wikipedia.org/wiki/Javascript"
125 target="_top">Javascript</a> and thus <span class="QUOTE">"fragile"</span>. So if <span class=
126 "emphasis"><i class="EMPHASIS">still</i></span> a problem, we have an <a href=
127 "../user-manual/actions-file.html#ALIASES" target="_top">alias</a> just for such sticky situations:</p>
128 <table border="0" bgcolor="#E0E0E0" width="100%">
131 <pre class="SCREEN"># Gmail is a _fragile_ site:
133 { <tt class="LITERAL">fragile</tt> }
135 mail.google.com</pre>
139 <p>Be sure to flush your browser's caches whenever making these kinds of changes, just to make sure the changes
140 <span class="QUOTE">"take"</span>.</p>
141 <p>Make sure the domain, host and path are appropriate as well. Your browser can tell you where you are
142 specifically and you should use that information for your configuration settings. Note that above it is not
143 referenced as <tt class="LITERAL">gmail.com</tt>, which is a valid domain name.</p>
146 <h3 class="SECT2"><a name="CONFIGFILES" id="CONFIGFILES">3.9. What's the difference between the <span class=
147 "QUOTE">"Cautious"</span>, <span class="QUOTE">"Medium"</span> and <span class="QUOTE">"Advanced"</span>
149 <p>Configuring <span class="APPLICATION">Privoxy</span> is not entirely trivial. To help you get started, we
150 provide you with three different default action <span class="QUOTE">"profiles"</span> in the web based actions
151 file editor at <a href="http://config.privoxy.org/show-status" target=
152 "_top">http://config.privoxy.org/show-status</a>. See the <a href="../user-manual/actions-file.html" target=
153 "_top"><i class="CITETITLE">User Manual</i></a> for a list of actions, and how the default profiles are set.</p>
154 <p>Where the defaults are likely to break some sites, exceptions for known popular <span class=
155 "QUOTE">"problem"</span> sites are included, but in general, the more aggressive your default settings are, the
156 more exceptions you will have to make later. New users are best to start off in <span class=
157 "QUOTE">"Cautious"</span> setting. This is safest and will have the fewest problems. See the <a href=
158 "../user-manual/index.html" target="_top"><i class="CITETITLE">User Manual</i></a> for a more detailed
160 <p>It should be noted that the <span class="QUOTE">"Advanced"</span> profile (formerly known as the <span class=
161 "QUOTE">"Adventuresome"</span> profile) is more aggressive, and will make use of some of <span class=
162 "APPLICATION">Privoxy's</span> advanced features. Use at your own risk!</p>
165 <h3 class="SECT2"><a name="BROWSECONFIG" id="BROWSECONFIG">3.10. Why can I change the configuration with a
166 browser? Does that not raise security issues?</a></h3>
167 <p>It may seem strange that regular users can edit the config files with their browsers, although the whole
168 <tt class="FILENAME">/etc/privoxy</tt> hierarchy belongs to the user <span class="QUOTE">"privoxy"</span>, with
169 only 644 permissions.</p>
170 <p>When you use the browser-based editor, <span class="APPLICATION">Privoxy</span> itself is writing to the
171 config files. Because <span class="APPLICATION">Privoxy</span> is running as the user <span class=
172 "QUOTE">"privoxy"</span>, it can update its own config files.</p>
173 <p>If you run <span class="APPLICATION">Privoxy</span> for multiple untrusted users (e.g. in a LAN) or aren't
174 entirely in control of your own browser, you will probably want to make sure that the web-based editor and remote
175 toggle features are <span class="QUOTE">"off"</span> by setting <span class="QUOTE">"<tt class="LITERAL"><a href=
176 "../user-manual/config.html#ENABLE-EDIT-ACTIONS" target="_top">enable-edit-actions</a> 0</tt>"</span> and
177 <span class="QUOTE">"<tt class="LITERAL"><a href="../user-manual/config.html#ENABLE-REMOTE-TOGGLE" target=
178 "_top">enable-remote-toggle</a> 0</tt>"</span> in the <a href="../user-manual/config.html" target="_top">main
179 configuration file</a>.</p>
180 <p>As of <span class="APPLICATION">Privoxy</span> 3.0.7 these options are disabled by default.</p>
183 <h3 class="SECT2"><a name="FILTERFILE" id="FILTERFILE">3.11. What is the <tt class="FILENAME">default.filter</tt>
184 file? What is a <span class="QUOTE">"filter"</span>?</a></h3>
185 <p>The <a href="../user-manual/filter-file.html" target="_top"><tt class="FILENAME">default.filter</tt></a> file
186 is where <span class="emphasis"><i class="EMPHASIS">filters</i></span> as supplied by the developers are defined.
187 Filters are a special subset of actions that can be used to modify or remove web page content or headers on the
188 fly. Content filters can be applied to <span class="emphasis"><i class="EMPHASIS">anything</i></span> in the page
189 source, header filters can be applied to either server or client headers. Regular expressions are used to
191 <p>There are a number of pre-defined filters to deal with common annoyances. The filters are only defined here,
192 to invoke them, you need to use the <a href="../user-manual/actions-file.html#FILTER" target="_top"><tt class=
193 "LITERAL">filter</tt> action</a> in one of the actions files. Content filtering is automatically disabled for
194 inappropriate MIME types, but if you know better than Privoxy what should or should not be filtered you can
195 filter any content you like.</p>
196 <p>Filters should <span class="emphasis"><i class="EMPHASIS">not</i></span> be confused with <a href=
197 "../user-manual/actions-file.html#BLOCK" target="_top"><tt class="LITERAL">blocks</tt></a>, which is a completely
198 different action, and is more typically used to block ads and unwanted sites.</p>
199 <p>If you are familiar with regular expressions, and HTML, you can look at the provided <tt class=
200 "FILENAME">default.filter</tt> with a text editor and define your own filters. This is potentially a very
201 powerful feature, but requires some expertise in both regular expressions and HTML/HTTP. You should place any
202 modifications to the default filters, or any new ones you create in a separate file, such as <tt class=
203 "FILENAME">user.filter</tt>, so they won't be overwritten during upgrades. The ability to define multiple filter
204 files in <tt class="FILENAME">config</tt> is a new feature as of v. 3.0.5.</p>
205 <p>There is no GUI editor option for this part of the configuration, but you can disable/enable the various
206 pre-defined filters of the included <tt class="FILENAME">default.filter</tt> file with the <a href=
207 "http://config.privoxy.org/show-status" target="_top">web-based actions file editor</a>. Note that the custom
208 actions editor must be explicitly enabled in the main config file (see <a href=
209 "../user-manual/config.html#ENABLE-EDIT-ACTIONS" target="_top">enable-edit-actions</a>).</p>
210 <p>If you intend to develop your own filters, you might want to have a look at <a href=
211 "https://www.fabiankeil.de/sourcecode/pft/" target="_top">Privoxy-Filter-Test</a>.</p>
214 <h3 class="SECT2"><a name="LANCONFIG" id="LANCONFIG">3.12. How can I set up Privoxy to act as a proxy for my
216 <p>By default, <span class="APPLICATION">Privoxy</span> only responds to requests from <tt class=
217 "LITERAL">127.0.0.1</tt> (localhost). To have it act as a server for a network, this needs to be changed in the
218 <a href="../user-manual/config.html" target="_top">main configuration file</a>. Look for the <tt class=
219 "LITERAL"><a href="../user-manual/config.html#LISTEN-ADDRESS" target="_top">listen-address</a></tt> option, which
220 may be commented out with a <span class="QUOTE">"#"</span> symbol. Make sure it is uncommented, and assign it the
221 address of the LAN gateway interface, and port number to use. Assuming your LAN address is 192.168.1.1 and you
222 wish to run <span class="APPLICATION">Privoxy</span> on port 8118, this line should look like:</p>
223 <table border="0" bgcolor="#E0E0E0" width="100%">
226 <pre class="SCREEN"> listen-address 192.168.1.1:8118</pre>
230 <p>Save the file, and restart <span class="APPLICATION">Privoxy</span>. Configure all browsers on the network
231 then to use this address and port number.</p>
232 <p>Alternately, you can have <span class="APPLICATION">Privoxy</span> listen on all available interfaces:</p>
233 <table border="0" bgcolor="#E0E0E0" width="100%">
236 <pre class="SCREEN"> listen-address :8118</pre>
240 <p>And then use <span class="APPLICATION">Privoxy's</span> <a href="../user-manual/config.html#PERMIT-ACCESS"
241 target="_top">permit-access</a> feature to limit connections. A firewall in this situation is recommended as
243 <p>The above steps should be the same for any TCP network, regardless of operating system.</p>
244 <p>If you run <span class="APPLICATION">Privoxy</span> on a LAN with untrusted users, we recommend that you
245 double-check the <a href="../user-manual/config.html#ACCESS-CONTROL" target="_top">access control and
246 security</a> options!</p>
249 <h3 class="SECT2"><a name="NOSEEUM" id="NOSEEUM">3.13. Instead of ads, now I get a checkerboard pattern. I don't
250 want to see anything.</a></h3>
251 <p>The replacement for blocked images can be controlled with the <a href=
252 "../user-manual/actions-file.html#SET-IMAGE-BLOCKER" target="_top"><tt class="LITERAL">set-image-blocker</tt>
253 action</a>. You have the choice of a checkerboard pattern, a transparent 1x1 GIF image (aka <span class=
254 "QUOTE">"blank"</span>), or a redirect to a custom image of your choice. Note that this choice only has effect
255 for images which are blocked as images, i.e. whose URLs match both a <tt class="LITERAL"><a href=
256 "../user-manual/actions-file.html#HANDLE-AS-IMAGE" target="_top">handle-as-image</a></tt> <span class=
257 "emphasis"><i class="EMPHASIS">and</i></span> <tt class="LITERAL"><a href=
258 "../user-manual/actions-file.html#BLOCK" target="_top">block</a></tt> action.</p>
259 <p>If you want to see nothing, then change the <a href="../user-manual/actions-file.html#SET-IMAGE-BLOCKER"
260 target="_top"><tt class="LITERAL">set-image-blocker</tt> action</a> to <span class="QUOTE">"blank"</span>. This
261 can be done by editing the <tt class="FILENAME">user.action</tt> file, or through the <a href=
262 "http://config.privoxy.org/show-status" target="_top">web-based actions file editor</a>.</p>
265 <h3 class="SECT2"><a name="WHYSEEUM" id="WHYSEEUM">3.14. Why would anybody want to see a checkerboard
267 <p>Remember that <a href="general.html#WHATSANAD">telling which image is an ad and which isn't</a>, is an
268 educated guess. While we hope that the standard configuration is rather smart, it will make occasional mistakes.
269 The checkerboard image is visually decent, and it shows you where images have been blocked, which can be very
270 helpful in case some navigation aid or otherwise innocent image was erroneously blocked. It is recommended for
271 new users so they can <span class="QUOTE">"see"</span> what is happening. Some people might also enjoy seeing how
272 many banners they <span class="emphasis"><i class="EMPHASIS">don't</i></span> have to see.</p>
275 <h3 class="SECT2"><a name="BLOCKEDBYTEXT" id="BLOCKEDBYTEXT">3.15. I see some images being replaced with text
276 instead of the checkerboard image. Why and how do I get rid of this?</a></h3>
277 <p>This happens when the banners are not embedded in the HTML code of the page itself, but in separate HTML
278 (sub)documents that are loaded into (i)frames or (i)layers, and these external HTML documents are blocked. Being
279 non-images they get replaced by a substitute HTML page rather than a substitute image, which wouldn't work out
280 technically, since the browser expects and accepts only HTML when it has requested an HTML document.</p>
281 <p>The substitute page adapts to the available space and shows itself as a miniature two-liner if loaded into
282 small frames, or full-blown with a large red "BLOCKED" banner if space allows.</p>
283 <p>If you prefer the banners to be blocked by images, you must see to it that the HTML documents in which they
284 are embedded are not blocked. Clicking the <span class="QUOTE">"See why"</span> link offered in the substitute
285 page will show you which rule blocked the page. After changing the rule and un-blocking the HTML documents, the
286 browser will try to load the actual banner images and the usual image blocking will (hopefully!) kick in.</p>
289 <h3 class="SECT2"><a name="SRVANY" id="SRVANY">3.16. Can Privoxy run as a service on Win2K/NT/XP?</a></h3>
290 <p>Yes. Version 3.0.5 introduces full <span class="APPLICATION">Windows</span> service functionality. See
291 <a href="../user-manual/installation.html#INSTALLATION-PACK-WIN" target="_top">the <i class="CITETITLE">User
292 Manual</i></a> for details on how to install and configure <span class="APPLICATION">Privoxy</span> as a
294 <p>Earlier 3.x versions could run as a system service using <b class="COMMAND">srvany.exe</b>. See the discussion
295 at <a href="https://sourceforge.net/tracker/?func=detail&atid=361118&aid=485617&group_id=11118"
296 target="_top">https://sourceforge.net/tracker/?func=detail&atid=361118&aid=485617&group_id=11118</a>,
297 for details, and a sample configuration.</p>
300 <h3 class="SECT2"><a name="OTHERPROXY" id="OTHERPROXY">3.17. How can I make Privoxy work with other
302 <p>This can be done and is often useful to combine the benefits of <span class="APPLICATION">Privoxy</span> with
303 those of a another proxy, for example to cache content. See the <a href="../user-manual/config.html#FORWARDING"
304 target="_top">forwarding chapter</a> in the <a href="../user-manual/index.html" target="_top">User Manual</a>
305 which describes how to do this. If you intend to use Privoxy with Tor, please also have a look at <a href=
306 "misc.html#TOR">How do I use Privoxy together with Tor</a>.</p>
309 <h3 class="SECT2"><a name="PORT-80" id="PORT-80">3.18. Can I just set Privoxy to use port 80 and thus avoid
310 individual browser configuration?</a></h3>
311 <p>No, its more complicated than that. This only works with special kinds of proxies known as <span class=
312 "QUOTE">"intercepting"</span> proxies (<a href="configuration.html#INTERCEPTING">see below</a>).</p>
315 <h3 class="SECT2"><a name="TRANSPARENT" id="TRANSPARENT">3.19. Can Privoxy run as a <span class=
316 "QUOTE">"transparent"</span> proxy?</a></h3>
317 <p>The whole idea of Privoxy is to modify client requests and server responses in all sorts of ways and therefore
318 it's not a transparent proxy as described in <a href="http://tools.ietf.org/html/rfc2616" target="_top">RFC
320 <p>However, some people say <span class="QUOTE">"transparent proxy"</span> when they mean <span class=
321 "QUOTE">"intercepting proxy"</span>. If you are one of them, please read the <a href=
322 "configuration.html#INTERCEPTING">next entry</a>.</p>
325 <h3 class="SECT2"><a name="INTERCEPTING" id="INTERCEPTING">3.20. Can Privoxy run as a <span class=
326 "QUOTE">"intercepting"</span> proxy?</a></h3>
327 <p><span class="APPLICATION">Privoxy</span> can't intercept traffic itself, but it can handle requests that where
328 intercepted and redirected with a packet filter (like <span class="APPLICATION">PF</span> or <span class=
329 "APPLICATION">iptables</span>), as long as the <tt class="LITERAL">Host</tt> header is present.</p>
330 <p>As the <tt class="LITERAL">Host</tt> header is required by HTTP/1.1 and as most web sites rely on it anyway,
331 this limitation shouldn't be a problem.</p>
332 <p>Please refer to your packet filter's documentation to learn how to intercept and redirect traffic into
333 <span class="APPLICATION">Privoxy</span>. Afterward you just have to configure <span class=
334 "APPLICATION">Privoxy</span> to <a href="../user-manual/config.html#ACCEPT-INTERCEPTED-REQUESTS" target=
335 "_top">accept intercepted requests</a>.</p>
338 <h3 class="SECT2"><a name="OUTLOOK" id="OUTLOOK">3.21. How can I configure Privoxy for use with Outlook?</a></h3>
339 <p>Versions of <span class="APPLICATION">Outlook</span> prior to Office 2007, use <span class=
340 "APPLICATION">Internet Explorer</span> components to both render HTML, and fetch any HTTP requests that may be
341 embedded in an HTML email. So however you have <span class="APPLICATION">Privoxy</span> configured to work with
342 IE, this configuration should automatically be shared, at least with older version of Internet Explorer.</p>
343 <p>Starting with Office 2007, Microsoft is instead using the MS-Word rendering engine with Outlook. It is unknown
344 whether this can be configured to use a proxy.</p>
347 <h3 class="SECT2"><a name="OUTLOOK-MORE" id="OUTLOOK-MORE">3.22. How can I have separate rules just for HTML
349 <p>The short answer is, you can't. <span class="APPLICATION">Privoxy</span> has no way of knowing which
350 particular application makes a request, so there is no way to distinguish between web pages and HTML mail.
351 <span class="APPLICATION">Privoxy</span> just blindly proxies all requests. In the case of <span class=
352 "APPLICATION">Outlook Express</span> (see above), OE uses IE anyway, and there is no way for <span class=
353 "APPLICATION">Privoxy</span> to ever be able to distinguish between them (nor could any other proxy type
354 application for that matter).</p>
355 <p>For a good discussion of some of the issues involved (including privacy and security issues), see <a href=
356 "https://sourceforge.net/tracker/?func=detail&atid=211118&aid=629518&group_id=11118" target=
357 "_top">https://sourceforge.net/tracker/?func=detail&atid=211118&aid=629518&group_id=11118</a>.</p>
360 <h3 class="SECT2"><a name="SNEAKY-COOKIES" id="SNEAKY-COOKIES">3.23. I sometimes notice cookies sneaking through.
362 <p><a href="http://en.wikipedia.org/wiki/Browser_cookie" target="_top">Cookies</a> can be set in several ways.
363 The classic method is via the <tt class="LITERAL">Set-Cookie</tt> HTTP header. This is straightforward, and an
364 easy one to manipulate, such as the <span class="APPLICATION">Privoxy</span> concept of <a href=
365 "../user-manual/actions-file.html#SESSION-COOKIES-ONLY" target="_top">session-cookies-only</a>. There is also the
366 possibility of using <a href="http://en.wikipedia.org/wiki/Javascript" target="_top">Javascript</a> to set
367 cookies (<span class="APPLICATION">Privoxy</span> calls these <tt class="LITERAL">content-cookies</tt>). This is
368 trickier because the syntax can vary widely, and thus requires a certain amount of guesswork. It is not realistic
369 to catch all of these short of disabling Javascript, which would break many sites. And lastly, if the cookies are
370 embedded in a HTTPS/SSL secure session via Javascript, they are beyond <span class="APPLICATION">Privoxy's</span>
371 reach unless you enable <a href="../user-manual/actions-file.html#HTTPS-INSPECTION" target=
372 "_top">https-inspection</a>.</p>
373 <p>All in all, <span class="APPLICATION">Privoxy</span> can help manage cookies in general, can help minimize the
374 loss of privacy posed by cookies, but can't realistically stop all cookies.</p>
377 <h3 class="SECT2"><a name="EVIL-COOKIES" id="EVIL-COOKIES">3.24. Are all cookies bad? Why?</a></h3>
378 <p>No, in fact there are many beneficial uses of <a href="http://en.wikipedia.org/wiki/Browser_cookie" target=
379 "_top">cookies</a>. Cookies are just a method that browsers can use to store data between pages, or between
380 browser sessions. Sometimes there is a good reason for this, and the user's life is a bit easier as a result. But
381 there is a long history of some websites taking advantage of this layer of trust, and using the data they glean
382 from you and your browsing habits for their own purposes, and maybe to your potential detriment. Such sites are
383 using you and storing their data on your system. That is why the privacy conscious watch from whom those cookies
384 come, and why they really <span class="emphasis"><i class="EMPHASIS">need</i></span> to be there.</p>
385 <p>See the <a href="http://en.wikipedia.org/wiki/Browser_cookie" target="_top">Wikipedia cookie definition</a>
389 <h3 class="SECT2"><a name="ALLOW-COOKIES" id="ALLOW-COOKIES">3.25. How can I allow permanent cookies for my
390 trusted sites?</a></h3>
391 <p>There are several actions that relate to cookies. The default behavior is to allow only <span class=
392 "QUOTE">"session cookies"</span>, which means the cookies only last for the current browser session. This
393 eliminates most kinds of abuse related to cookies. But there may be cases where you want cookies to last.</p>
394 <p>To disable all cookie actions, so that cookies are allowed unrestricted, both in and out, for <tt class=
395 "LITERAL">example.com</tt>:</p>
396 <table border="0" bgcolor="#E0E0E0" width="100%">
400 "SCREEN"> { -crunch-incoming-cookies -crunch-outgoing-cookies -session-cookies-only -filter{content-cookies} }
405 <p>Place the above in <tt class="FILENAME">user.action</tt>. Note that some of these may be off by default
406 anyway, so this might be redundant, but there is no harm being explicit in what you want to happen. <tt class=
407 "FILENAME">user.action</tt> includes an alias for this situation, called <tt class=
408 "LITERAL">allow-all-cookies</tt>.</p>
411 <h3 class="SECT2"><a name="MULTIPLES" id="MULTIPLES">3.26. Can I have separate configurations for different
413 <p>Each instance of <span class="APPLICATION">Privoxy</span> has its own configuration, including such attributes
414 as the TCP port that it listens on. What you can do is run multiple instances of <span class=
415 "APPLICATION">Privoxy</span>, each with a unique <a href="../user-manual/config.html#LISTEN-ADDRESS" target=
416 "_top">listen-address</a> configuration setting, and configuration path, and then each of these can have their
417 own configurations. Think of it as per-port configuration.</p>
418 <p>Simple enough for a few users, but for large installations, consider having groups of users that might share
419 like configurations.</p>
422 <h3 class="SECT2"><a name="WHITELISTS" id="WHITELISTS">3.27. Can I set-up Privoxy as a whitelist of <span class=
423 "QUOTE">"good"</span> sites?</a></h3>
424 <p>Sure. There are a couple of things you can do for simple white-listing. Here's one real easy one:</p>
425 <table border="0" bgcolor="#E0E0E0" width="100%">
428 <pre class="SCREEN"> ############################################################
430 ############################################################
431 { <a href="../user-manual/actions-file.html#BLOCK" target="_top">+block</a> }
434 ############################################################
436 ############################################################
437 { <a href="../user-manual/actions-file.html#BLOCK" target="_top">-block</a> }
440 games.example.com</pre>
444 <p>This allows access to only those three sites by first blocking all URLs, and then subsequently allowing three
445 specific exceptions.</p>
446 <p>Another approach is <span class="APPLICATION">Privoxy's</span> <tt class="LITERAL">trustfile</tt> concept,
447 which incorporates the notion of <span class="QUOTE">"trusted referrers"</span>. See the <a href=
448 "../user-manual/config.html#TRUSTFILE" target="_top">Trust documentation</a> for details.</p>
449 <p>These are fairly simple approaches and are not completely foolproof. There are various other configuration
450 options that should be disabled (described elsewhere here and in <a href="../user-manual/" target="_top">the User
451 Manual</a>) so that users can't modify their own configuration and easily circumvent the whitelist.</p>
454 <h3 class="SECT2"><a name="NO-ADBLOCK" id="NO-ADBLOCK">3.28. How can I turn off ad-blocking?</a></h3>
455 <p>Ad blocking is achieved through a complex application of various <span class="APPLICATION">Privoxy</span>
456 <a href="../user-manual/actions-file.html" target="_top">actions</a>. These actions are deployed against simple
457 images, banners, flash animations, text pages, JavaScript, pop-ups and pop-unders, etc., so its not as simple as
458 just turning one or two actions off. The various actions that make up <span class="APPLICATION">Privoxy</span> ad
459 blocking are hard-coded into the default configuration files. It has been assumed that everyone using
460 <span class="APPLICATION">Privoxy</span> is interested in this particular feature.</p>
461 <p>If you want to do without this, there are several approaches you can take: You can manually undo the many
462 block rules in <tt class="FILENAME">default.action</tt>. Or even easier, just create your own <tt class=
463 "FILENAME">default.action</tt> file from scratch without the many ad blocking rules, and corresponding
464 exceptions. Or lastly, if you are not concerned about the additional blocks that are done for privacy reasons,
465 you can very easily over-ride <span class="emphasis"><i class="EMPHASIS">all</i></span> blocking with the
466 following very simple rule in your <tt class="FILENAME">user.action</tt>:</p>
467 <table border="0" bgcolor="#E0E0E0" width="100%">
470 <pre class="SCREEN"> # Unblock everybody, everywhere
471 { <a href="../user-manual/actions-file.html#BLOCK" target="_top">-block</a> }
472 / # UN-Block *all* URLs</pre>
476 <p>Or even a more comprehensive reversing of various ad related actions:</p>
477 <table border="0" bgcolor="#E0E0E0" width="100%">
480 <pre class="SCREEN"> # Unblock everybody, everywhere, and turn off appropriate filtering, etc
481 { <a href="../user-manual/actions-file.html#BLOCK" target="_top">-block</a> \
482 <a href="../user-manual/actions-file.html#FILTER-BANNERS-BY-SIZE" target="_top">-filter{banners-by-size}</a> \
483 <a href="../user-manual/actions-file.html#FILTER-BANNERS-BY-LINK" target="_top">-filter{banners-by-link}</a> \
484 <tt class="LITERAL">allow-popups</tt> \
486 / # UN-Block *all* URLs and allow ads</pre>
490 <p>This last <span class="QUOTE">"action"</span> in this compound statement, <tt class=
491 "LITERAL">allow-popups</tt>, is an <a href="../user-manual/actions-file.html#ALIASES" target="_top">alias</a>
492 that disables various pop-up blocking features.</p>
495 <h3 class="SECT2"><a name="TEMPLATES" id="TEMPLATES">3.29. How can I have custom template pages, like the
496 <span class="emphasis"><i class="EMPHASIS">BLOCKED</i></span> page?</a></h3>
497 <p><span class="APPLICATION">Privoxy</span> <span class="QUOTE">"templates"</span> are specialized text files
498 utilized by <span class="APPLICATION">Privoxy</span> for various purposes and can easily be modified using any
499 text editor. All the template pages are installed in a sub-directory appropriately named: <tt class=
500 "FILENAME">templates</tt>. Knowing something about HTML syntax will of course be helpful.</p>
501 <p>Be forewarned that the default templates are subject to being overwritten during upgrades. You can, however,
502 create completely new templates, place them in another directory and specify the alternate path in the main
503 <tt class="FILENAME">config</tt>. For details, have a look at the <a href="../user-manual/config.html#TEMPLDIR"
504 target="_top">templdir</a> option.</p>
507 <h3 class="SECT2"><a name="BLOCKALL" id="BLOCKALL">3.30. How can I remove the <span class="QUOTE">"Go There
508 Anyway"</span> link from the <span class="emphasis"><i class="EMPHASIS">BLOCKED</i></span> page?</a></h3>
509 <p>There is more than one way to do it (although Perl is not involved).</p>
510 <p>Editing the BLOCKED template page (see above) may dissuade some users, but this method is easily circumvented.
511 Where you need this level of control, you might want to build <span class="APPLICATION">Privoxy</span> from
512 source, and disable various features that are available as compile-time options. You should <b class=
513 "COMMAND">configure</b> the sources as follows:</p>
514 <table border="0" bgcolor="#E0E0E0" width="100%">
517 <pre class="SCREEN"> ./configure --disable-toggle --disable-editor --disable-force</pre>
521 <p>This will create an executable with hard-coded security features so that <span class=
522 "APPLICATION">Privoxy</span> does not allow easy bypassing of blocked sites, or changing the current
523 configuration via any connected user's web browser.</p>
524 <p>Finally, all of these features can also be toggled on/off via options in <span class=
525 "APPLICATION">Privoxy's</span> main <a href="../user-manual/config.html#ACCESS-CONTROL" target="_top">config</a>
526 file which means you don't have to recompile anything.</p>
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