LDAP Authentication

WeBWorK contains support for authenticating WeBWorK logins against an LDAP database. The WeBWorK LDAP authentication module supports vanilla LDAP as well as Bind accounts and Active Directory search.

Configuring WeBWorK to use LDAP authentication

LDAP authentication may be enabled for all WeBWorK courses on a server, or for individual courses on a server. The latter may be useful when a single WeBWorK installation is being used to host courses at multiple institutions.

Configuring LDAP for all courses

To use LDAP authentication for all courses on a WeBWorK server, in webwork2/conf/authen_ldap.conf.dist (or perhaps webwork2/conf/global.conf on older versions of WeBWorK) you must edit the $authen{user_module} hash to enable the LDAP authentication module and then edit the $authen{ldap_options} hash to configure the LDAP module for your specific environment. You may need to uncomment the line include("conf/authen_ldap.conf"); in the localOverrides.conf file.

First, enable LDAP authentication by modifying $authen{user_module} in authen_ldap.conf.dist to read:

$authen{user_module} = {
        sql_moodle => "WeBWorK::Authen::Moodle",
        "*" => "WeBWorK::Authen::LDAP",
};

Next, configure LDAP authentication by modifying the $authen{ldap_options} hash in authen_ldap.conf.dist. The exact settings here are all site-specific. The items in this hash are as follows:

key	description
net_ldap_hosts	A reference to an array listing hosts to attempt to connect to. Examples: auth.myschool.edu (uses LDAP scheme and port 389) ldap://auth.myschool.edu:666 (non-standard port) ldaps://auth.myschool.edu (uses LDAPS scheme and port 636) ldaps://auth.myschool.edu:389 (SSL on non-SSL port)
net_ldap_options	Options passed to Net::LDAP's constructor. See Net::LDAP#CONSTRUCTOR for details.
net_ldap_base	Tells the WeBWorK server which part of the external directory tree to search. This is site-specific and may be something equivalent to the organization, group, or domain name (AD) of external directory; e.g. "ou=people,dc=myschool,dc=edu"
bindAccount	Set bindAccount = 1 to authenticate to LDAP server. Must set searchDN and bindPassword.
searchDN	For use when bindAccount = 1. The searchDN represents the user on the external LDAP server permitted to search the LDAP directory within the defined search base; e.g searchDN = "cn=administrator,dc=myschool,dc=edu".
bindPassword	Password for Bind user identified by searchDN. Note that in perl double quoted strings are interpolated, so expressions like bindPassword = "pas$word"; and bindPassword = "p@ssword"; should be replaced by bindPassword = "pas\$word"; and bindPassword = "p\@ssword"; or bindPassword = 'pas$word'; and bindPassword = 'p@ssword';.
net_ldap_rdn	The LDAP module searches for a DN whose RDN matches the username entered by the user. The net_ldap_rdn will depend on your LDAP setup. By default net_ldap_rdn = "sAMAccountName for use with Active Directory. If you schema uses UID as RDN set net_ldap_rdn = "uid"
failover	If failover = "all", then LDAP failures will be checked against the WeBWorK database. If failover = "local", then only users who don't exist in the LDAP database will be checked against the WeBWorK database. If failover = 0, then no attempts will be checked against the WeBWorK database. The setting failover = 1 is equivalent to failover="all".

Configuring LDAP on a course-by-course basis

Each course has a course.conf file in its root directory whose purpose is to override settings in global.conf with course-specific configuration parameters. This file is accessible from the file manager in the course by navigating up one directory from the course templates directory which is displayed by default in the file manager. Therefore, by adding the appropriate $authen{user_module} and $authen{ldap_options} hashes to course.conf one can override the global LDAP settings on the server.

Legacy

If you are using WeBWorK 2.3.0 you should upgrade!!! :-)

If you insist on using WeBWorK 2.3.0, you'll have to set the following configuration options in webwork2/lib/WeBWorK/Authen/LDAP.pm:

constant	description
$TIMEOUT	Seconds to wait for LDAP server.
$PORT	TCP port to connect to on LDAP server.
$VERSION	LDAP protocol version to use.
$BASE	LDAP base string.
@HOST	This is kind of confusing. This is a one-element array, containing an arrayref. The arrayref is a list of servers to attempt to connect to. You'll see what to do when you look at the file. (Yes, this is a bug.)

Security Considerations

You must make sure that each accounts in your WeBWorK course "belongs" to the same person as the LDAP account with the same user ID. User ID mapping is not supported.

With failover = "all", the LDAP module always fails over to checking the WeBWorK password if LDAP authentication fails.

It is suggested to run the authentication over SSL so that the password is encrypted and not sent in plain text.

Limitations

Users must still be added to WeBWorK manually. The LDAP module itself does not do this for you.

Gateway test proctors cannot authenticate with LDAP. They will have to have valid passwords in the WeBWorK database.

Forum Discussions

• LDAP Search 25 May 2011
• ldap failover not working 9 Sept 2010
• Authentication problems 21 Dec 2009
• LDAP credentials 20 Mar 2009

Development

• WeBWorK::Authen::LDAP source code

Bug Reports

{{#bugzilla: |id=1926,1927 |lastcomment=1 }}