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What happens to login credentials after I authenticate with lightdm? Is there are process that stores them? Would this be something that PAM caches somewhere? Would lightdm hang on to them?

The problem I'm trying to solve is re-requesting TGT without prompting for password long after user has been authenticated. For example, I authenticated with lightdm, worked on my laptop, started VPN session, logged into a different network and would like to acquire TGT without having to enter my password again. The only way I can see doing this if credentials are stored somewhere and I can re-use them or if I could somehow figure out who (which process) takes care of getting TGT after I initially authenticate (which does happen automatically) and sort of "poke" that process to go do it again (but that means the process would have to have my credentials stored somewhere)...

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No, your credentials are not stored or cached anywhere, when you log in. If you want to use single sign-on for access to resources on your machine and a network, then you should set up a kerberos authentication server, and set up your services to use kerberos for authentication. With kerberos, when you log in, the server gives you a session token which is cached, and which can then be used by other applications to authenticate to resources within the domain of the server providing the token.

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I am actually using kerberos and what you describe is working, except for when I authenticate before I'm on the network. Then, once I'm on the network, something (some process), does go out and pulls TGT (ticket granting ticket), but it takes a while.. I was wondering if I could speed up that process, but not sure how. One way was to re-use credentials and the other way would be to figure out which process responsible for TGT pull and kick it off (or signal it) sooner. – user228247 Dec 24 '13 at 0:15

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