[CentOS] /usr/sbin/usermod -p doesn't update MAX_DAYS - workaround?

Thu Jan 28 13:20:35 UTC 2010
Sean Carolan <scarolan at gmail.com>

I have a large group of Linux servers that I inherited from a previous
administrator.  Unfortunately there is no single sign-on configured so
each server has it's own local accounts with local authentication.
Normally I use ssh keys and a handy shell script to change passwords
on all these machines with the usermod -p command.  We are able to
update the password on on one server and push the encrypted password
out to all the others.

If, however, we turn on password aging with "chage -M 90 username"
then try to update passwords with usermod, the aging info for the
account is not updated even though the password has been changed.
Apparently this must be done manually for each and every server with
the passwd command.  This is not practical.

In the long run we're going to try and get some kind of centralized
authentication, but in the meantime does anyone have an idea for a