Real SSO feeling through the SPNEGO/Kerberos Login Flow for the Shibboleth Identity Provider v3

Windows users can now extend their SSO feeling to the SWITCHaai login page, provided their client is a member of a Windows domain. They no longer need to re-enter their username and password they’ve already entered to log in to the Windows desktop. Actually, Kerberos enabled non-Windows clients like Linux or Mac could profit of such enhanced SSO, too.

The Shibboleth Identity Provider (IdP) achieves this through SPNEGO-based Kerberos authentication (i.e. password-less web authentication via Kerberos). While version 2 of the Shibboleth IdP supported this through an extension, the Shibboleth IdP version 3 provides built-in support through the SPNEGO/Kerberos Login Flow authentication mechanism.

The SPNEGO/Kerberos Login Flow module was developed in co-operation by SWITCH and the Fachhochschule Nordwestschweiz (FHNW). As the FHNW already developed the extension for the IdP v2, they brought their existing experience into the project to re-implement the same functionality for IdP v3. Eventually, the SPNEGO/Kerberos Login Flow got an integral part of the Shibboleth Identity Provider version 3.2.0 in November 2015 and has been available since then.

The SPNEGO/Kerberos Login Flow has proven to run successfully on the IdPs of the Fachhochschule Nordwestschweiz and the Pädagogische Hochschule Bern, since these IdPs were migrated to IdP v3.

To use the SPNEGO-based authentication, the following prerequisites must be fulfilled:

  • A Kerberos infrastructure must be available (e. g. a Windows domain).
  • The IdP server must be registered as a Kerberos service at the Kerberos Key Distribution Center (KDC).
  • Kerberos client software must be installed on the IdP server.
  • The Shibboleth Identity Provider software must be configured accordingly.
  • The web browsers on the clients require specific configuration to use this authentication method.

Organisations being interested in using the SPNEGO-based authentication on their own IdP can find comprehensive documentation in the Shibboleth Wiki: SPNEGO/Kerberos Login Flow

SPNEGO-based authentication is also offered as an option to the Identity Provider Hosting service provided by SWITCH.