Privoxy 3.0.6 User Manual
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# 7. The Main Configuration File

Again, the main configuration file is named `config` on Linux/Unix/BSD and OS/2, and `config.txt` on Windows. Configuration lines consist of an initial keyword followed by a list of values, all separated by whitespace (any number of spaces or tabs). For example:

``

confdir /etc/privoxy

Assigns the value `/etc/privoxy` to the option `confdir` and thus indicates that the configuration directory is named "/etc/privoxy/".

All options in the config file except for `confdir` and `logdir` are optional. Watch out in the below description for what happens if you leave them unset.

The main config file controls all aspects of Privoxy's operation that are not location dependent (i.e. they apply universally, no matter where you may be surfing).

## 7.1. Local Set-up Documentation

If you intend to operate Privoxy for more users than just yourself, it might be a good idea to let them know how to reach you, what you block and why you do that, your policies, etc.

#### 7.1.1. user-manual

Specifies:

  Location of the Privoxy User Manual.

Type of value:

  A fully qualified URI

Default value:

  Unset

Effect if unset:

  http://www.privoxy.org/`version`/user-manual/ will be used, where `version` is the Privoxy version.

Notes:

  The User Manual URI is the single best source of information on Privoxy, and is used for help links from some of the internal CGI pages. The manual itself is normally packaged with the binary distributions, so you probably want to set this to a locally installed copy.

  Examples:

  The best all purpose solution is simply to put the full local `PATH` to where the User Manual is located:

        user-manual  /usr/share/doc/privoxy/user-manual

  The User Manual is then available to anyone with access to the proxy, by following the built-in URL: `http://config.privoxy.org/user-manual/` (or the shortcut: `http://p.p/user-manual/`).

  If the documentation is not on the local system, it can be accessed from a remote server, as:

        user-manual  http://example.com/privoxy/user-manual/

  Warning
  If set, this option should be the first option in the config file, because it is used while the config file is being read on start-up.

#### 7.1.2. trust-info-url

Specifies:

  A URL to be displayed in the error page that users will see if access to an untrusted page is denied.

Type of value:

  URL

Default value:

  Two example URL are provided

Effect if unset:

  No links are displayed on the "untrusted" error page.

Notes:

  The value of this option only matters if the experimental trust mechanism has been activated. (See trustfile above.)

  If you use the trust mechanism, it is a good idea to write up some on-line documentation about your trust policy and to specify the URL(s) here. Use multiple times for multiple URLs.

  The URL(s) should be added to the trustfile as well, so users don't end up locked out from the information on why they were locked out in the first place!

#### 7.1.3. admin-address

Specifies:

  An email address to reach the proxy administrator.

Type of value:

  Email address

Default value:

  Unset

Effect if unset:

  No email address is displayed on error pages and the CGI user interface.

Notes:

  If both `admin-address` and `proxy-info-url` are unset, the whole "Local Privoxy Support" box on all generated pages will not be shown.

#### 7.1.4. proxy-info-url

Specifies:

  A URL to documentation about the local Privoxy setup, configuration or policies.

Type of value:

  URL

Default value:

  Unset

Effect if unset:

  No link to local documentation is displayed on error pages and the CGI user interface.

Notes:

  If both `admin-address` and `proxy-info-url` are unset, the whole "Local Privoxy Support" box on all generated pages will not be shown.

  This URL shouldn't be blocked ;-)

## 7.2. Configuration and Log File Locations

Privoxy can (and normally does) use a number of other files for additional configuration, help and logging. This section of the configuration file tells Privoxy where to find those other files.

The user running Privoxy, must have read permission for all configuration files, and write permission to any files that would be modified, such as log files and actions files.

#### 7.2.1. confdir

Specifies:

  The directory where the other configuration files are located

Type of value:

  Path name

Default value:

  /etc/privoxy (Unix) or Privoxy installation dir (Windows)

Effect if unset:

  Mandatory

Notes:

  No trailing "`/`", please

#### 7.2.2. logdir

Specifies:

  The directory where all logging takes place (i.e. where `logfile` and `jarfile` are located)

Type of value:

  Path name

Default value:

  /var/log/privoxy (Unix) or Privoxy installation dir (Windows)

Effect if unset:

  Mandatory

Notes:

  No trailing "`/`", please

#### 7.2.3. actionsfile

Specifies:

  The actions file(s) to use

Type of value:

  File name, relative to `confdir`, without the `.action` suffix

Default values:

  standard # Internal purposes, no editing recommended
  default # Main actions file
  user # User customizations

Effect if unset:

  No actions are taken at all. Simple neutral proxying.

Notes:

  Multiple `actionsfile` lines are permitted, and are in fact recommended!

  The default values include standard.action, which is used for internal purposes and should be loaded, default.action, which is the "main" actions file maintained by the developers, and `user.action`, where you can make your personal additions.

  Actions files are where all the per site and per URL configuration is done for ad blocking, cookie management, privacy considerations, etc. There is no point in using Privoxy without at least one actions file.

#### 7.2.4. filterfile

Specifies:

  The filter file(s) to use

Type of value:

  File name, relative to `confdir`

Default value:

  default.filter (Unix) or default.filter.txt (Windows)

Effect if unset:

  No textual content filtering takes place, i.e. all `+filter{`name`}` actions in the actions files are turned neutral.

Notes:

  Multiple `filterfile` lines are permitted.

  The filter files contain content modification rules that use regular expressions. These rules permit powerful changes on the content of Web pages, and optionally the headers as well, e.g., you could disable your favorite JavaScript annoyances, re-write the actual displayed text, or just have some fun playing buzzword bingo with web pages.

  The `+filter{`name`}` actions rely on the relevant filter (`name`) to be defined in a filter file!

  A pre-defined filter file called `default.filter` that contains a number of useful filters for common problems is included in the distribution. See the section on the `filter` action for a list.

  It is recommended to place any locally adapted filters into a separate file, such as `user.filter`.

#### 7.2.5. logfile

Specifies:

  The log file to use

Type of value:

  File name, relative to `logdir`

Default value:

  logfile (Unix) or privoxy.log (Windows)

Effect if unset:

  No log file is used, all log messages go to the console (`STDERR`).

Notes:

  The logfile is where all logging and error messages are written. The level of detail and number of messages are set with the `debug` option (see below). The logfile can be useful for tracking down a problem with Privoxy (e.g., it's not blocking an ad you think it should block) but in most cases you probably will never look at it.

  Your logfile will grow indefinitely, and you will probably want to periodically remove it. On Unix systems, you can do this with a cron job (see "man cron"). For Red Hat, a logrotate script has been included.

  On SuSE Linux systems, you can place a line like "/var/log/privoxy.* +1024k 644 nobody.nogroup" in `/etc/logfiles`, with the effect that cron.daily will automatically archive, gzip, and empty the log, when it exceeds 1M size.

  Any log files must be writable by whatever user Privoxy is being run as (default on UNIX, user id is "privoxy").

#### 7.2.6. jarfile

Specifies:

  The file to store intercepted cookies in

Type of value:

  File name, relative to `logdir`

Default value:

  Unset (commented out). When activated: jarfile (Unix) or privoxy.jar (Windows)

Effect if unset:

  Intercepted cookies are not stored in a dedicated log file.

Notes:

  The jarfile may grow to ridiculous sizes over time.

  If debug 8 (show header parsing) is enabled, cookies are written to the logfile with the rest of the headers.

#### 7.2.7. trustfile

Specifies:

  The name of the trust file to use

Type of value:

  File name, relative to `confdir`

Default value:

  Unset (commented out). When activated: trust (Unix) or trust.txt (Windows)

Effect if unset:

  The entire trust mechanism is disabled.

Notes:

  The trust mechanism is an experimental feature for building white-lists and should be used with care. It is NOT recommended for the casual user.

  If you specify a trust file, Privoxy will only allow access to sites that are specified in the trustfile. Sites can be listed in one of two ways:

  Prepending a `~` character limits access to this site only (and any sub-paths within this site), e.g. `~www.example.com` allows access to `~www.example.com/features/news.html`, etc.

  Or, you can designate sites as trusted referrers, by prepending the name with a `+` character. The effect is that access to untrusted sites will be granted -- but only if a link from this trusted referrer was used to get there. The link target will then be added to the "trustfile" so that future, direct accesses will be granted. Sites added via this mechanism do not become trusted referrers themselves (i.e. they are added with a `~` designation). There is a limit of 512 such entries, after which new entries will not be made.

  If you use the `+` operator in the trust file, it may grow considerably over time.

  It is recommended that Privoxy be compiled with the `--disable-force`, `--disable-toggle` and `--disable-editor` options, if this feature is to be used.

  Possible applications include limiting Internet access for children.

## 7.3. Debugging

These options are mainly useful when tracing a problem. Note that you might also want to invoke Privoxy with the `--no-daemon` command line option when debugging.

#### 7.3.1. debug

Specifies:

  Key values that determine what information gets logged to the logfile.

Type of value:

  Integer values

Default value:

  12289 (i.e.: URLs plus informational and warning messages)

Effect if unset:

  Nothing gets logged.

Notes:

  The available debug levels are:

        debug         1 # show each GET/POST/CONNECT request
        debug         2 # show each connection status
        debug         4 # show I/O status
        debug         8 # show header parsing
        debug        16 # log all data into the logfile
        debug        32 # debug force feature
        debug        64 # debug regular expression filter
        debug       128 # debug fast redirects
        debug       256 # debug GIF de-animation
        debug       512 # Common Log Format
        debug      1024 # debug kill pop-ups
        debug      2048 # CGI user interface
        debug      4096 # Startup banner and warnings.
        debug      8192 # Non-fatal errors

  To select multiple debug levels, you can either add them or use multiple `debug` lines.

  A debug level of 1 is informative because it will show you each request as it happens. 1, 4096 and 8192 are highly recommended so that you will notice when things go wrong. The other levels are probably only of interest if you are hunting down a specific problem. They can produce a hell of an output (especially 16).

  The reporting of fatal errors (i.e. ones which crash Privoxy) is always on and cannot be disabled.

  If you want to use CLF (Common Log Format), you should set "debug 512" ONLY and not enable anything else.

#### 7.3.2. single-threaded

Specifies:

  Whether to run only one server thread

Type of value:

  None

Default value:

  Unset

Effect if unset:

  Multi-threaded (or, where unavailable: forked) operation, i.e. the ability to serve multiple requests simultaneously.

Notes:

  This option is only there for debug purposes and you should never need to use it. It will drastically reduce performance.

## 7.4. Access Control and Security

This section of the config file controls the security-relevant aspects of Privoxy's configuration.

#### 7.4.1. listen-address

Specifies:

  The IP address and TCP port on which Privoxy will listen for client requests.

Type of value:

  [`IP-Address`]:`Port`

Default value:

  127.0.0.1:8118

Effect if unset:

  Bind to 127.0.0.1 (localhost), port 8118. This is suitable and recommended for home users who run Privoxy on the same machine as their browser.

Notes:

  You will need to configure your browser(s) to this proxy address and port.

  If you already have another service running on port 8118, or if you want to serve requests from other machines (e.g. on your local network) as well, you will need to override the default.

  If you leave out the IP address, Privoxy will bind to all interfaces (addresses) on your machine and may become reachable from the Internet. In that case, consider using access control lists (ACL's, see below), and/or a firewall.

  If you open Privoxy to untrusted users, you will also want to turn off the `enable-edit-actions` and `enable-remote-toggle` options!

Example:

  Suppose you are running Privoxy on a machine which has the address 192.168.0.1 on your local private network (192.168.0.0) and has another outside connection with a different address. You want it to serve requests from inside only:

        listen-address  192.168.0.1:8118

#### 7.4.2. toggle

Specifies:

  Initial state of "toggle" status

Type of value:

  1 or 0

Default value:

  1

Effect if unset:

  Act as if toggled on

Notes:

  If set to 0, Privoxy will start in "toggled off" mode, i.e. behave like a normal, content-neutral proxy where all ad blocking, filtering, etc are disabled. See `enable-remote-toggle` below. This is not really useful anymore, since toggling is much easier via the web interface than via editing the `conf` file.

  The windows version will only display the toggle icon in the system tray if this option is present.

#### 7.4.3. enable-remote-toggle

Specifies:

  Whether or not the web-based toggle feature may be used

Type of value:

  0 or 1

Default value:

  1

Effect if unset:

  The web-based toggle feature is disabled.

Notes:

  When toggled off, Privoxy acts like a normal, content-neutral proxy, i.e. it acts as if none of the actions applied to any URL.

  For the time being, access to the toggle feature can not be controlled separately by "ACLs" or HTTP authentication, so that everybody who can access Privoxy (see "ACLs" and `listen-address` above) can toggle it for all users. So this option is not recommended for multi-user environments with untrusted users.

  Note that you must have compiled Privoxy with support for this feature, otherwise this option has no effect.

#### 7.4.4. enable-remote-http-toggle

Specifies:

  Whether or not Privoxy recognizes special HTTP headers to change its behaviour.

Type of value:

  0 or 1

Default value:

  1

Effect if unset:

  Privoxy ignores special HTTP headers.

Notes:

  When toggled on, the client can change Privoxy's behaviour by setting special HTTP headers. Currently the only supported special header is "X-Filter: No", to disable filtering for the ongoing request, even if it is enabled in one of the action files.

  If you are using Privoxy in a multi-user environment or with untrustworthy clients and want to enforce filtering, you will have to disable this option, otherwise you can ignore it.

#### 7.4.5. enable-edit-actions

Specifies:

  Whether or not the web-based actions file editor may be used

Type of value:

  0 or 1

Default value:

  1

Effect if unset:

  The web-based actions file editor is disabled.

Notes:

  For the time being, access to the editor can not be controlled separately by "ACLs" or HTTP authentication, so that everybody who can access Privoxy (see "ACLs" and `listen-address` above) can modify its configuration for all users. So this option is not recommended for multi-user environments with untrusted users.

  Note that you must have compiled Privoxy with support for this feature, otherwise this option has no effect.

#### 7.4.6. ACLs: permit-access and deny-access

Specifies:

  Who can access what.

Type of value:

  `src_addr`[/`src_masklen`] [`dst_addr`[/`dst_masklen`]]

  Where `src_addr` and `dst_addr` are IP addresses in dotted decimal notation or valid DNS names, and `src_masklen` and `dst_masklen` are subnet masks in CIDR notation, i.e. integer values from 2 to 30 representing the length (in bits) of the network address. The masks and the whole destination part are optional.

Default value:

  Unset

Effect if unset:

  Don't restrict access further than implied by `listen-address`

Notes:

  Access controls are included at the request of ISPs and systems administrators, and are not usually needed by individual users. For a typical home user, it will normally suffice to ensure that Privoxy only listens on the localhost (127.0.0.1) or internal (home) network address by means of the listen-address option.

  Please see the warnings in the FAQ that this proxy is not intended to be a substitute for a firewall or to encourage anyone to defer addressing basic security weaknesses.

  Multiple ACL lines are OK. If any ACLs are specified, then the Privoxy talks only to IP addresses that match at least one `permit-access` line and don't match any subsequent `deny-access` line. In other words, the last match wins, with the default being `deny-access`.

  If Privoxy is using a forwarder (see `forward` below) for a particular destination URL, the `dst_addr` that is examined is the address of the forwarder and NOT the address of the ultimate target. This is necessary because it may be impossible for the local Privoxy to determine the IP address of the ultimate target (that's often what gateways are used for).

  You should prefer using IP addresses over DNS names, because the address lookups take time. All DNS names must resolve! You can not use domain patterns like "*.org" or partial domain names. If a DNS name resolves to multiple IP addresses, only the first one is used.

  Denying access to particular sites by ACL may have undesired side effects if the site in question is hosted on a machine which also hosts other sites.

Examples:

  Explicitly define the default behavior if no ACL and `listen-address` are set: "localhost" is OK. The absence of a `dst_addr` implies that all destination addresses are OK:

        permit-access  localhost

  Allow any host on the same class C subnet as www.privoxy.org access to nothing but www.example.com:

        permit-access  www.privoxy.org/24 www.example.com/32

  Allow access from any host on the 26-bit subnet 192.168.45.64 to anywhere, with the exception that 192.168.45.73 may not access www.dirty-stuff.example.com:

        permit-access  192.168.45.64/26
        deny-access    192.168.45.73    www.dirty-stuff.example.com

#### 7.4.7. buffer-limit

Specifies:

  Maximum size of the buffer for content filtering.

Type of value:

  Size in Kbytes

Default value:

  4096

Effect if unset:

  Use a 4MB (4096 KB) limit.

Notes:

  For content filtering, i.e. the `+filter` and `+deanimate-gif` actions, it is necessary that Privoxy buffers the entire document body. This can be potentially dangerous, since a server could just keep sending data indefinitely and wait for your RAM to exhaust -- with nasty consequences. Hence this option.

  When a document buffer size reaches the `buffer-limit`, it is flushed to the client unfiltered and no further attempt to filter the rest of the document is made. Remember that there may be multiple threads running, which might require up to `buffer-limit` Kbytes each, unless you have enabled "single-threaded" above.

## 7.5. Forwarding

This feature allows routing of HTTP requests through a chain of multiple proxies. It can be used to better protect privacy and confidentiality when accessing specific domains by routing requests to those domains through an anonymous public proxy. Or to use a caching proxy to speed up browsing. Or chaining to a parent proxy may be necessary because the machine that Privoxy runs on has no direct Internet access.

Also specified here are SOCKS proxies. Privoxy supports the SOCKS 4 and SOCKS 4A protocols.

#### 7.5.1. forward

Specifies:

  To which parent HTTP proxy specific requests should be routed.

Type of value:

  `target_pattern` `http_parent`[:`port`]

  where `target_pattern` is a URL pattern that specifies to which requests (i.e. URLs) this forward rule shall apply. Use `/` to denote "all URLs". `http_parent`[:`port`] is the DNS name or IP address of the parent HTTP proxy through which the requests should be forwarded, optionally followed by its listening port (default: 8080). Use a single dot (`.`) to denote "no forwarding".

Default value:

  Unset

Effect if unset:

  Don't use parent HTTP proxies.

Notes:

  If `http_parent` is ".", then requests are not forwarded to another HTTP proxy but are made directly to the web servers.

  Multiple lines are OK, they are checked in sequence, and the last match wins.

Examples:

  Everything goes to an example anonymizing proxy, except SSL on port 443 (which it doesn't handle):

        forward   /      anon-proxy.example.org:8080
        forward   :443   .

  Everything goes to our example ISP's caching proxy, except for requests to that ISP's sites:

        forward   /                  caching-proxy.example-isp.net:8000
        forward   .example-isp.net   .

#### 7.5.2. forward-socks4 and forward-socks4a

Specifies:

  Through which SOCKS proxy (and to which parent HTTP proxy) specific requests should be routed.

Type of value:

  `target_pattern` `socks_proxy`[:`port`] `http_parent`[:`port`]

  where `target_pattern` is a URL pattern that specifies to which requests (i.e. URLs) this forward rule shall apply. Use `/` to denote "all URLs". `http_parent` and `socks_proxy` are IP addresses in dotted decimal notation or valid DNS names (`http_parent` may be "." to denote "no HTTP forwarding"), and the optional `port` parameters are TCP ports, i.e. integer values from 1 to 64535

Default value:

  Unset

Effect if unset:

  Don't use SOCKS proxies.

Notes:

  Multiple lines are OK, they are checked in sequence, and the last match wins.

  The difference between `forward-socks4` and `forward-socks4a` is that in the SOCKS 4A protocol, the DNS resolution of the target hostname happens on the SOCKS server, while in SOCKS 4 it happens locally.

  If `http_parent` is ".", then requests are not forwarded to another HTTP proxy but are made (HTTP-wise) directly to the web servers, albeit through a SOCKS proxy.

Examples:

  From the company example.com, direct connections are made to all "internal" domains, but everything outbound goes through their ISP's proxy by way of example.com's corporate SOCKS 4A gateway to the Internet.

        forward-socks4a   /              socks-gw.example.com:1080  www-cache.example-isp.net:8080
        forward           .example.com   .

  A rule that uses a SOCKS 4 gateway for all destinations but no HTTP parent looks like this:

        forward-socks4   /               socks-gw.example.com:1080  .

  To chain Privoxy and Tor, both running on the same system, you should use the rule:

        forward-socks4   /               127.0.0.1:9050 .

  The public Tor network can't be used to reach your local network, therefore it's a good idea to make some exceptions:

        forward         192.168.*.*/     .
        forward            10.*.*.*/     .
        forward           127.*.*.*/     .

  Unencrypted connections to systems in these address ranges will be as (un)secure as the local network is, but the alternative is that you can't reach the network at all.

  If you also want to be able to reach servers in your local network by using their names, you will need additional exceptions that look like this:

       forward           localhost/     .

#### 7.5.3. Advanced Forwarding Examples

If you have links to multiple ISPs that provide various special content only to their subscribers, you can configure multiple Privoxies which have connections to the respective ISPs to act as forwarders to each other, so that your users can see the internal content of all ISPs.

Assume that host-a has a PPP connection to isp-a.net. And host-b has a PPP connection to isp-b.net. Both run Privoxy. Their forwarding configuration can look like this:

host-a:

      forward    /           .
      forward    .isp-b.net  host-b:8118

host-b:

      forward    /           .
      forward    .isp-a.net  host-a:8118

Now, your users can set their browser's proxy to use either host-a or host-b and be able to browse the internal content of both isp-a and isp-b.

If you intend to chain Privoxy and squid locally, then chain as `browser -> squid -> privoxy` is the recommended way.

Assuming that Privoxy and squid run on the same box, your squid configuration could then look like this:

      # Define Privoxy as parent proxy (without ICP)
      cache_peer 127.0.0.1 parent 8118 7 no-query

      # Define ACL for protocol FTP
      acl ftp proto FTP

      # Do not forward FTP requests to Privoxy
      always_direct allow ftp

      # Forward all the rest to Privoxy
      never_direct allow all

You would then need to change your browser's proxy settings to squid's address and port. Squid normally uses port 3128. If unsure consult `http_port` in `squid.conf`.

You could just as well decide to only forward requests for Windows executables through a virus-scanning parent proxy, say, on `antivir.example.com`, port 8010:

      forward   /                          .
      forward   /.*\.(exe|com|dll|zip)$    antivir.example.com:8010

#### 7.5.4. forwarded-connect-retries

Specifies:

  How often Privoxy retries if a forwarded connection request fails.

Type of value:

  `Number of retries.`

Default value:

  0

Effect if unset:

  Forwarded connections are treated like direct connections and no retry attempts are made.

Notes:

  `forwarded-connect-retries` is mainly interesting for socks4a connections, where Privoxy can't detect why the connections failed. The connection might have failed because of a DNS timeout in which case a retry makes sense, but it might also have failed because the server doesn't exist or isn't reachable. In this case the retry will just delay the appearance of Privoxy's error message.

  Only use this option, if you are getting many forwarding related error messages, that go away when you try again manually. Start with a small value and check Privoxy's logfile from time to time, to see how many retries are usually needed.

Examples:

  forwarded-connect-retries 1

## 7.6. Windows GUI Options

Privoxy has a number of options specific to the Windows GUI interface:

If "activity-animation" is set to 1, the Privoxy icon will animate when "Privoxy" is active. To turn off, set to 0.

``

activity-animation 1

If "log-messages" is set to 1, Privoxy will log messages to the console window:

``

log-messages 1

If "log-buffer-size" is set to 1, the size of the log buffer, i.e. the amount of memory used for the log messages displayed in the console window, will be limited to "log-max-lines" (see below).

Warning: Setting this to 0 will result in the buffer to grow infinitely and eat up all your memory!

``

log-buffer-size 1

log-max-lines is the maximum number of lines held in the log buffer. See above.

``

log-max-lines 200

If "log-highlight-messages" is set to 1, Privoxy will highlight portions of the log messages with a bold-faced font:

``

log-highlight-messages 1

The font used in the console window:

``

log-font-name Comic Sans MS

Font size used in the console window:

``

log-font-size 8

"show-on-task-bar" controls whether or not Privoxy will appear as a button on the Task bar when minimized:

``

show-on-task-bar 0

If "close-button-minimizes" is set to 1, the Windows close button will minimize Privoxy instead of closing the program (close with the exit option on the File menu).

``

close-button-minimizes 1

The "hide-console" option is specific to the MS-Win console version of Privoxy. If this option is used, Privoxy will disconnect from and hide the command console.

``

#hide-console

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