Nginx -- mod_auth_tkt

[Christian Klinger]

Hello,

i try to replace a existing apache, which works as a reverse
proxy, with nginx.

In general this seems to be not a great problem. But we use in
the existing environment mod_auth_tkt [1] for authentication.
One requirement in this configuration is that the authentication should 
be the job of the reverse proxy with a login_page instead of the
browsers login popup window.

Is there a module in nginx which does something similar to mod_auth_tkt?
Are there any alternatives in this direction?

Thanks for your help & suggestions...

Christian

[1] http://www.openfusion.com.au/labs/mod_auth_tkt/