This is a fixed version my previous patch.
I split it to 3 patches:
passwdqc.diff.gz - password checking pam module.
passwd.diff.gz - passwd utility that works throuth pam, not directly on
master.passwd file (this support local passwd file and the NIS one).
etc.diff - /etc/pam.d/passwd file, on default this tell to passwd to
simply change password, but when passwdqc line is unhashed, this tell
that first check passwd if is enougth strong.
this version support NOFSCHG flag in make.conf file.
Is anyone who interesed this patch and want see it in DFly?