mod_auth_remote v1.0 - a single signon module using basic auth ( for Apache 2.0 )
README mod_auth_remote ( Apache 2.0 authentication module )
This module is a very simple, lightweight method of setting up a single signon system across multiple web-applicaitions hosted on different servers.
The actual authentication & authorization system is deployed on a single server instead of each individual server. All other servers are built with mod_auth_remote enabled. When a request comes in, mod_auth_remote obtains the client username & password from the client via basic authentication scheme.
It then builds a HTTP header with authorization header built from the client's userid:passwd. mod_auth_remote then makes a HEAD request to the authentication server. On reciept of a 2XX response, the client is validated; for all other responses the client is not validated.
Why I wrote mod_auth_remote ?
I have a bunch of web applications running on a bunch of machines ...
- My authentication code is heavy & I don't want to implement it on all of your servers. (I use mod_perl and require a Database access to authenticate)
- Most of my web applications use a single signon
- Two different applications running under the same server could access 2 different authentication models without any pain
INSTALLATION
This module can be easily built statically into the httpd just like any other auth module. This module does not require any special library or external stuff to work !
mod_auth_remote keywords/directives
AuthRemoteServer : The remote server against which the authentication has to take place AuthRemotePort : The port on which the remote server is runing AuthRemoteURL : The (optional) path on the remote server which has to be accessed ( should have been AuthRemotePatch :-) )
As you would have noticed these 3 configuration directives are used to build the complete URL against which mod_auth_remote authenticates.
Sample Configuration for a httpd (my.server.com)
<Directory ~ "/application_1/">
AuthType Basic AuthName CHICKEN_RUN AuthRemoteServer auth1.saju.com AuthRemotePort 80 AuthRemoteURL /One/Auth/method require valid-user
</Directory>
<Directory ~ "/application_2/">
AuthType Basic AuthName BIG-CHIEF AuthRemoteServer auth1.saju.com AuthRemotePort 80 AuthRemoteURL /luke/takes/a/walk require valid-user
</Directory>
<Directory ~ "/application_3/">
AuthType Basic AuthName ONE_RING AuthRemoteServer www.sauron.com AuthRemotePort 1290 AuthRemoteURL /auth require valid-user
</Directory>
When a request is made to http://my.server.com/application_1, mod_auth_remote uses the basic auth scheme to get the client's username:passwd and then authenticates the user against http://auth1.saju.com:80/One/Auth/method using basic auth.
Similiarily a request coming to http://my.server.com/application_3 is automatically authenticated against http://www.sauron.com:1290/auth
So, the biggest advantage here is that 'my.server.com' can host 3 different applications having 3 different user sets and 'my.server.com' need not host any sort of authentication infrastructure (like having access to LDAP server or DB etc), it need not have any authentication code at all !!
Similarily 10 different servers could access 'auth1.saju.com/<url>' for authenticating users without having to duplicating the authentication infrastructure 10 times !