Proxy Server Authentication Methods And Access Control

Squid Proxy Server is a powerful and flexible open-source web proxy server that can be used for caching and filtering of web content. What sets Squid apart from other proxy servers is its support for Active Directory (LDAP) authentication. In this article, we’ll dive into the Squid Proxy Server Configuration With Active Directory (LDAP).

Prerequisites

Before configuring Squid Proxy Server with Active Directory (LDAP), you need to have the following:

A Linux server with Squid Proxy Server installed
An Active Directory (LDAP) server
User accounts on the Active Directory (LDAP) server

Step-by-Step Configuration

1. Install Required Packages

First, we need to install some required packages on our Linux server:

sudo apt-get update sudo apt-get install squid krb5-user auth-client-config

The squid package installs the Squid Proxy Server, while krb5-user and auth-client-config packages are required for Kerberos authentication.

2. Configure Kerberos Authentication

Next, we need to configure our Kerberos client to communicate with our Active Directory (LDAP) server. Edit the /etc/krb5.conf file:

[libdefaults] 	default_realm = EXAMPLE.COM 	dns_lookup_realm = false 	dns_lookup_kdc = false  [realms] 	EXAMPLE.COM =  		kdc = AD.EXAMPLE.COM 		admin_server = AD.EXAMPLE.COM 		default_domain = EXAMPLE.COM 	  [domain_realm] 	.example.com = EXAMPLE.COM 	example.com = EXAMPLE.COM

Replace EXAMPLE.COM with your domain name and AD.EXAMPLE.COM with the hostname of your Active Directory (LDAP) server.

3. Configure Squid

Edit the /etc/squid/squid.conf file:

auth_param negotiate program /usr/lib/squid/negotiate_kerberos_auth -s HTTP/proxy.example.com@EXAMPLE.COM auth_param negotiate children 10 auth_param negotiate keep_alive on  acl authenticated proxy_auth REQUIRED  http_access allow authenticated http_access deny all

Replace example.com with your domain name and proxy.example.com with the hostname of your Squid Proxy Server.

Now, restart the Squid Proxy Server:

sudo systemctl restart squid

4. Verify the Configuration

Finally, we need to verify that our Squid Proxy Server is working with Active Directory (LDAP) authentication. Open a web browser and enter the URL of your Squid Proxy Server:

http://proxy.example.com:3128

You should see a login prompt. Enter your Active Directory (LDAP) credentials to authenticate:

Username: jdoe Password: *********

If everything is configured correctly, you should now be able to browse the web through your Squid Proxy Server with Active Directory (LDAP) authentication!

Conclusion

Configuring Squid Proxy Server with Active Directory (LDAP) authentication can be a bit tricky, but it’s well worth the effort. With this configuration, you’ll have a powerful and flexible web proxy server that can be used for caching and filtering web content while providing secure authentication through your Active Directory (LDAP) server.

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So, go ahead and give it a try. You’ll be glad you did!