While the squid proxy server has quite a few different flavours of authentication available, one of the most basic ones, pam_auth, is also one of the most useful ones to get you started quickly. pam_auth let’s anyone who has a local account access the squid proxy. In large environments you probably want to use ldap authentication eventually, but pam_auth is great for testing purposes.
Let’s install squid3 first:
# yum install squid
A minimal squid configuration file for an authenticating proxy is not too different from the default configuration file that comes with the squid rpm package. The changed parts are hightlighted
# # Recommended minimum configuration: # 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 auth_param basic program /usr/lib64/squid/pam_auth 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 # 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 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 password proxy_auth REQUIRED 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 deny !localnet http_access allow localhost http_access allow password # 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 visible_hostname squid3.yourdomain.com
Configuration of the squid PAM authentication helper pam_auth is quite simple. It just needs a PAM service to be configured /etc/pam.d/
#%PAM-1.0 auth include password-auth account include password-auth
pam_auth also need the correct permissions to access the user password database, which basically requires it to run as root (path is
/usr/lib64/squid/pam_auth on CentOS 6 and
/usr/lib64/squid/basic_pam_auth on recent versions of Fedora)
chmod u+s /usr/lib64/squid/basic_pam_auth
Please note, that it’s not recommended to use pam_auth for authenticating to a local unix shadow password database. You should at the very least make sure, that it’s in a directory, regular users can’t access.
That’s it. Now enable and start the squid proxy server:
# systemctl enable squid.service ln -s '/usr/lib/systemd/system/squid.service' '/etc/systemd/system/multi-user.target.wants/squid.service' # systemctl start squid.service
The proxy is then reachable at squid3.yourdomain.com:3128