[...]
auth		required	pam_unix.so [...]
auth		optional	pam_ecryptfs.so unwrap
auth		optional	pam_permit.so
auth		optional	pam_mount.so

[...]

password	required	pam_unix.so [...]
password	optional	pam_ecryptfs.so

[...]
session		required	pam_unix.so
[...]
session		optional	pam_mount.so