# Redirecting Pages through CGIProxy with Squid

There are a number of legal to use publicly accessible installations of
[CGIProxy](https://www.jmarshall.com/tools/cgiproxy/). They're usually quite
fast and some even have SSL certificates. One of my favourites is CTunnel
https://www.ctunnel.com/ (broken link nowadays).

On my network I use a [Squid](https://www.squid-cache.org/) HTTP proxy. I
thought that it would be nice if I could configure Squid to redirect certain
HTTP requests through CTunnel, eg requests for http://www.torrentreactor.net/ to
hide my IP address from the destination site and therefore logs.

To do this, I abused the Squid access controls and deny_info options. These
options were designed so you could block requests for certain pages, and
redirect the user to a failure page which explains why the request was blocked.
First of all I created a file at /etc/squid/ctunnel_list.txt which contained a
list of regular expressions of HTTP requests I want to redirect:

```console
root@server:/etc/squid# head -1 ctunnel_list.txt
^http\:\/\/([^\/]+\.)*torrentreactor\.net\/
```

Then I added the following configuration to /etc/squid/squid.conf:

```text
acl         ctunnel_list url_regex -i "/etc/squid/ctunnel_list.txt"
http_access deny         ctunnel_list
deny_info   https://www.ctunnel.com/index.php/1010110A/?username=%s ctunnel_list
```

Now when my web browser makes any request for any url on torrentreactor.net or
any of the other regular expressions in my ctunnel_list.txt file, Squid
redirects me to a version proxied through https://www.ctunnel.com/ Magic