/etc/pam.d/quagga is in quagga-core 1.2.4-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 | # Any user may call vtysh but only those belonging to the group quaggavty can
# actually connect to the socket and use the program.
auth sufficient pam_permit.so
|