Some documentations, blogs and forums and other examples on the web use pam_unix2 in /etc/pam.d/ configurations. An example taken from pam_winbind  manpage:auth      required        pam_env.soauth      sufficient      pam_unix2.soauth      required        pam_winbind.so  use_first_passaccount   requisite       pam_unix2.soaccount   required        pam_winbind.so  use_first_passpassword  sufficient      pam_winbind.sopassword  requisite       pam_pwcheck.so  cracklibpassword  required        pam_unix2.so    use_authtoksession   required        pam_unix2.sosession   required        pam_winbind.soIt seems pam_unix2 was merely meant to: additionally support bcrypt Blowfish-based password hashing (Debian RFP #237856).The manpages are: pam_unix and pam_unix2What is the difference between pam_unix.so and pam_unix2.so ? Which are still used? maintained? relevant ?
What is pam_unix2 / why doesn't it exist on some distributions?
pam