Setup Proxy Server on CentOS VPS

squid-proxyThere are various ways to use a proxy such as scraping other websites’ data,  accessing google and Facebook, accessing to a website which is only limited to users in a specific country. Although we can use some public, free proxy such as HideMyAss, it is more convenient to have a private proxy which is dedicated for you so we do not need to be headache with continuous switching among free proxies! This tutorial contains detailed steps to setup a private proxy server on CentOS VPS.

Setting up Squid Proxy Server on CentOS

[bash]yum update
yum install squid[/bash]

Configuring Squid for Private Access

[bash]cp /etc/squid/squid.conf /etc/squid/squid.conf.original
vi /etc/squid/squid.conf[/bash]

In the configuration file, change proxy listen port on http_port. Then we will use ncsa_auth for authorizing user access by adding the following lines to the configuration file:

[bash]
auth_param basic program /usr/lib64/squid/ncsa_auth /etc/squid/squid_access
auth_param basic children 5
auth_param basic realm Squid proxy-caching web server
auth_param basic credentialsttl 2 hours
auth_param basic casesensitive off
acl ncsaauth proxy_auth REQUIRED
http_access allow ncsaauth[/bash]

If your CentOS is in 32bit, change the above first line to

[bash]auth_param basic program /usr/lib/squid/ncsa_auth /etc/squid/squid_access[/bash]

Remember that the position of acl lines are critical: You must push the acl lines at the top of the squid config file to be sure that everything works well.

We will then need to create list of users who can access proxy server

[bash]touch /etc/squid/squid_access
htpasswd /etc/squid/squid_access proxyuser[/bash]

Then, restart squid:

[bash]service squid restart[/bash]

Enabling Squid when system starts

[bash]chkconfig squid on[/bash]

Sample squid.conf

[bash]
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

# Proxy with authentication
auth_param basic program /usr/lib/squid/ncsa_auth /etc/squid/squid_access
auth_param basic children 5
auth_param basic realm Squid proxy-caching web server
auth_param basic credentialsttl 2 hours
auth_param basic casesensitive off
acl ncsaauth proxy_auth REQUIRED
http_access allow ncsaauth

# Example rule allowing access from your local networks.
# Adapt to list your (internal) IP networks from where browsing
# should be allowed
acl localnet src 10.0.0.0/8 # RFC1918 possible internal network
acl localnet src 172.16.0.0/12 # RFC1918 possible internal network
acl localnet src 192.168.0.0/16 # RFC1918 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 CONNECT method CONNECT
#
# Recommended minimum Access Permission configuration:
#
# Only allow cachemgr access from localhost
http_access allow manager localhost
http_access deny manager

# Deny requests to certain unsafe ports
http_access deny !Safe_ports

# Deny CONNECT to other than secure SSL ports
http_access deny CONNECT !SSL_ports

# We strongly recommend the following be uncommented to protect innocent
# web applications running on the proxy server who think the only
# one who can access services on "localhost" is a local user
#http_access deny to_localhost

#
# INSERT YOUR OWN RULE(S) HERE TO ALLOW ACCESS FROM YOUR CLIENTS
#

# Example rule allowing access from your local networks.
# Adapt localnet in the ACL section to list your (internal) IP networks
# from where browsing should be allowed
http_access allow localnet
http_access allow localhost

# And finally deny all other access to this proxy
http_access deny all

# Squid normally listens to port 3128
http_port 3128

# We recommend you to use at least the following line.
hierarchy_stoplist cgi-bin ?

# Uncomment and adjust the following to add a disk cache directory.
#cache_dir ufs /var/spool/squid 100 16 256

# Leave coredumps in the first cache dir
coredump_dir /var/spool/squid

# Add any of your own refresh_pattern entries above these.
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
[/bash]

TroubleShooting

  1. If you face 110 connection timeout for some website and displaying an IPv6, then it seems squid is trying to lookup IPv6 for that website but failed. The simplest way to force squid using IPv4 is adding the following line into /etc/squid/squid.conf and restart squid after that:
    [bash]dns_v4_first on[/bash]
    . I have to say that this consumes me a lot of effort trying around before finding a working solution.

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