Package:Squid

Revision as of 17:18, 13 January 2014 by Duncan.Britton (Talk)

The Squid Proxy Server

This is a quick and dirty howto about getting Squid up und running in 5min...

What benefits one may get from using an anonymous proxy server? Well, I would say many things but the most important one is that you can browse the web anonymously without exposing your IP, location etc.. out there. Anyhow, even though I usually use OpenVPN or PPTP for safe browsing and such things, having a private anonymous proxy server in your toolbox is a nice thing. Furthermore, a cache is speeding up you daily internet connection with repeating objects getting out of the cache instead of downloading it again. Advanced filtering technics (Antivirus, Content, Ad-Blocks, etc) are also possible.

Please start always by refreshing your portage tree, like:

# emerge --sync

next, we search the portage tree for net-proxy/squid:

# emerge --search squid
=> net-analyzer/squid-graph
=> net-analyzer/squidsites
=> net-analyzer/squidview
=> net-proxy/squid
=> net-proxy/squidclamav
=> net-proxy/squidguard
=> sec-policy/selinux-squid

Next, we emerge squid using:

# emerge -av net-proxy/squid

Once it got installed, since this squid proxy setup will be using authentication to authenticate users via the ‘ncsa_auth‘ helper, we need to know the location of this helper so we can use it in our squid.confconfiguration file. To find this I’ll be using a tool named as ‘qfile‘ which is shipped in ‘app-portage/portage-utils‘.

  1. qfile ncsa_auth

net-proxy/squid (/usr/libexec/squid/ncsa_auth)

ok, so the auth helper is located in ‘/usr/libexec/squid/ncsa_auth’ so let’s setup Squid’s configuration file (/etc/squid/squid.conf). Make sure you change ‘XXX.XX.XX.XXX’ with your actual server’s IP address and edit anything else you want to suit your needs.


# cp /etc/squid/squid.conf{,_orig} && \cat > /etc/squid/squid.conf <<EOF
auth_param basic program /usr/libexec/squid/ncsa_auth /etc/squid/passwd
auth_param basic children 5
auth_param basic realm please login?
auth_param basic credentialsttl 2 hours
auth_param basic casesensitive off
acl ncsa_users proxy_auth REQUIRED
http_access allow ncsa_users
acl manager proto cache_object
acl localhost src 127.0.0.1/32 ::1
acl to_localhost dst 127.0.0.0/8 0.0.0.0/32 ::1
acl localnet src 10.0.0.0/8     
# RFC 1918 possible internal network
acl localnet src 172.16.0.0/12  
# RFC 1918 possible internal network
acl localnet src 192.168.0.0/16 
# RFC 1918 possible internal network
acl localnet src fc00::/7       
# RFC 4193 local private network range
acl localnet src fe80::/10      
# RFC 4291 link-local (directly plugged) machines
acl SSL_ports port 443
acl Safe_ports port 80          # http
acl Safe_ports port 21          # ftp
acl Safe_ports port 443         # https
acl Safe_ports port 70          # gopher
acl Safe_ports port 210         # wais
acl Safe_ports port 1025-65535  # unregistered ports
acl Safe_ports port 280         # http-mgmt
acl Safe_ports port 488         # gss-http
acl Safe_ports port 591         # filemaker
acl Safe_ports port 777         # multiling http
acl Safe_ports port 901         # SWAT
acl CONNECT method CONNECT
http_access allow manager localhost
http_access deny manager
http_access deny !Safe_ports
http_access deny CONNECT !SSL_ports
http_access allow localnet
http_access allow localhost
http_access allow localhost
http_access deny all
http_port 2222
coredump_dir /var/cache/squid
refresh_pattern ^ftp:           1440    20%     10080
refresh_pattern ^gopher:        1440    0%      1440
refresh_pattern -i (/cgi-bin/|\?) 0     0%      0
refresh_pattern .               0       20%     4320 
icp_access allow localnet
icp_access deny all
acl ip1 myip XXX.XX.XX.XXX
tcp_outgoing_address XXX.XX.XX.XXX ip1
cache_mgr mail@maiwald.tk
cache_mem 128 MB
visible_hostname ViruSzZ
maximum_object_size 20 MB
cache_dir ufs /var/cache/squid 512 32 512

forwarded_for off
request_header_access Allow allow all
request_header_access Authorization allow all
request_header_access WWW-Authenticate allow all
request_header_access Proxy-Authorization allow all
request_header_access Proxy-Authenticate allow all
request_header_access Cache-Control allow all
request_header_access Content-Encoding allow all
request_header_access Content-Length allow all
request_header_access Content-Type allow all
request_header_access Date allow all
request_header_access Expires allow all
request_header_access Host allow all
request_header_access If-Modified-Since allow all
request_header_access Last-Modified allow all
request_header_access Location allow all
request_header_access Pragma allow all
request_header_access Accept allow all
request_header_access Accept-Charset allow all
request_header_access Accept-Encoding allow all
request_header_access Accept-Language allow all
request_header_access Content-Language allow all
request_header_access Mime-Version allow all
request_header_access Retry-After allow all
request_header_access Title allow all
request_header_access Connection allow all
request_header_access Proxy-Connection allow all
request_header_access User-Agent allow all
request_header_access Cookie allow all
request_header_access All deny all
shutdown_lifetime 3 seconds
EOF

proceed with creating the ‘/etc/squid/passwd’ file and adding your user by executing:

  1. htpasswd -c /etc/squid/passwd your_user

(note that you need to omit the ‘-c’ switch when adding another user to the file)

then do a # squid -z to create the cache direcory. Finally, restart your squid server and check if it’s actually listening using:

  1. /etc/init.d/squid restart
  2. netstat -tunlp | grep 2222

tcp 0 0 0.0.0.0:2222 0.0.0.0:* LISTEN 482/(squid) if you like it to start on your system’s start-up, then you can execute:

  1. rc-update add squid default

To test it, for example I use Opera for this so I just go to ‘Settings → Preferences → Advanced → Network → Proxy Servers’ and set the browser to use the proxy server we just created.