CASA_auth_token is an authentication token infrastructure with support
for multiple authentication mechanisms with an emphasis on providing a
scalable single sign-on solution.

A key feature of CASA_auth_token is that its authentication tokens
contain identity information about the entity being authenticated. This
information is made available to the consuming services. The amount of
information contained in the tokens is configured on a per-service
basis. Because of this feature, we say that CASA_auth_token projects an
"Authenticated Identity".

The CASA_auth_token_server package contains the CASA (Common
Authentication Services Adapter) authentication token infrastructure
lower level libraries for token verification from native code ("C"). It
is recomended that this library not be invoked directly by
applications, instead it is recomended that appplication invoke its
services through the support modules provided to integrate with PAM or
the Apache Web Server.