Login with GnuPG smartcard
Libpam-poldi allows you to use your Fellowship crypto card to log in your GNU/Linux system.
First check if poldi detects your cardreader: ‘poldi-ctrl -d’. Unfortunately some cardreader doesn’t work with poldi and the existing free driver. For example the cardma4040 needs the non-free driver from Omnikey.
If poldi successfully detected your cardreader you can start to configure poldi. Poldi has a pretty good documentation so i will keep my explanations rather short.
- Root has to register the new card for poldi:
poldi-ctrl --register-card --account <your-user-account> --serialno <serialno of your card>
You can also execute this command without ‘–account <your-user-account>’ but than the user will not be able to install or update his card’s keys.
The serialno can be found by executing ‘gpg –card-status’ and looking for “Application ID”.
- Now we have to establish a mapping between the user and the smartcard he owns:
poldi-ctrl --associate --account <your-user-account> --serialno <serialno of your card>
- Now you have to write your public key into the appropriate key file (you have to do this within your user account)
- That’s it, now you can test it with ‘poldi-ctrl –test’
- Now you have to tell pam, that you want to use poldi.
Therefore you have to edit the files in /etc/pam.d. If, for example, you want to login to kdm with your card, edit the file /etc/pam.d/kdm. Replace the line ‘@include common-auth’ with
auth required pam_poldi.so
If you want to login unattended, use
auth required pam_poldi.so try-pin=123456 quiet
And if you want to fallback to regular unix passwords, use
auth sufficient pam_poldi.so try-pin=123456 quietauth required pam_unix.so nullok_secure
Now you should be able to use your GnuPG smartcard to log in your GNU/Linux system.
You can find a more detailed howto on my personal homepage which will still be available if this blog entry is already forgotten.