13.6. About SPNEGO

Simple and Protected GSS_API Negotiation Mechanism (SPNEGO) provides a mechanism for extending a Kerberos-based Single Sign On (SSO) environment for use in Web applications.
When an application on a client computer, such as a web browser, attempts to access a protect page on the web server, the server responds that authorization is required. The application then requests a service ticket from the Kerberos Key Distribution Center (KDC). After the ticket is obtained, the application wraps it in a request formatted for SPNEGO, and sends it back to the Web application, via the browser. The web container running the deployed Web application unpacks the request and authenticates the ticket. Upon successful authentication, access is granted.
SPNEGO works with all types of Kerberos providers, including the Kerberos service included in Red Hat Enterprise Linux and the Kerberos server which is an integral part of Microsoft Active Directory.