Description of problem: 1) pam should be able to ensure that a chosen password does not contain, repeat, or reverse the associated userID. 2) pam should be able ensure that the password does not contain a configurable number of the same characters consecutively. 3) pam should be configurable to prevent a user from choosing a password that is already associated with another userID. It should not tell the user that this is the reason why the password is being rejected. It must reuse an explanation that is already in use to reject passwords so as not to give away the reason.
1) and 2) seem reasonable and can be added to pam_cracklib. The 3) is very security critical thing to do correctly. It will have to be implemented very carefully in regards to timing attacks and so on. It also seems to me as really questionable thing whether it is useful at all (apart from giving a check on some list of items in some weird security standard). It will also need a standalone helper for SELinux as the module itself cannot read /etc/shadow.
This request was evaluated by Red Hat Product Management for inclusion in a Red Hat Enterprise Linux maintenance release. Product Management has requested further review of this request by Red Hat Engineering, for potential inclusion in a Red Hat Enterprise Linux Update release for currently deployed products. This request is not yet committed for inclusion in an Update release.
An advisory has been issued which should help the problem described in this bug report. This report is therefore being closed with a resolution of ERRATA. For more information on therefore solution and/or where to find the updated files, please follow the link below. You may reopen this bug report if the solution does not work for you. http://rhn.redhat.com/errata/RHBA-2009-0222.html