When using newgrp, shadow passwords (for both users and groups), and MD5 encrypted passwords, users trying to enter a group with a valid group password are denied entry to the group.
Looking into just removing newgrp altogether, since it is setuid root and seems to have all the usefulness of a colecovision binary...
WONTFIX - people seemed to complain rather vehemently about removing newgrp altogether, and it appears to be way too much work to fix newgrp to work with PAM to handle the gshadow passwords.
*** Bug 63975 has been marked as a duplicate of this bug. ***
Just confirming weirdo newgrp behaviour in RedHat Fedora 2.0 Actually IMHO what happens is: 1) gpasswd writes crypted (not md5) password to /etc/gshadow 2) newgrp tries to read crypted password form /etc/group Indeed, manual copy-and-paste of the crypted password from /etc/gshadow to /etc/group yields the expected newgrp behaviour, i.e. the password is recognized.
Cross-reference: please also see bug https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=85280 for the 'latest' in this saga.