Bug 1026921 - useless similarity check
Summary: useless similarity check
Keywords:
Status: CLOSED WONTFIX
Alias: None
Product: Red Hat Enterprise Linux 7
Classification: Red Hat
Component: libpwquality
Version: 7.0
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: rc
: ---
Assignee: Tomas Mraz
QA Contact: BaseOS QE Security Team
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2013-11-05 16:23 UTC by Karel Volný
Modified: 2013-11-05 16:48 UTC (History)
0 users

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed: 2013-11-05 16:48:58 UTC
Target Upstream Version:


Attachments (Terms of Use)

Description Karel Volný 2013-11-05 16:23:16 UTC
Description of problem:
I've just wanted to correct wrongly entered password (due to different keyboard layout) but was disallowed to. This makes no sense, as it can be easily workarounded by changing to something completely different at first, then changing to whatever you need, it just annoys the user.

Version-Release number of selected component (if applicable):
passwd-0.79-1.el7

How reproducible:
always

Steps to Reproduce:
1. run passwd (as ordinary user)
2. try to change the password to nearly the same as before just with one character different

Actual results:
you get BAD PASSWORD error and cannot use the new password

Expected results:
the password gets changed

Additional info:

Comment 2 Miloslav Trmač 2013-11-05 16:38:41 UTC
This check happens in *pwquality (... and is configured in system-auth, which Tomáš owns as well.)

Reassigning for him to consider.

FWIW, the workaround you propose can be, and is in some deployments, prevented by setting up a minimal password validity, and potentially remembering more past passwords.

Comment 3 Tomas Mraz 2013-11-05 16:48:38 UTC
You can also set up minimal number of days before you're allowed to change your password again.

The similarity check was there for a very long time and I don't think we should remove it. Basically all the checks in libpwquality/cracklib can be sometimes annoying but with this attitude we could drop pam_pwquality from the system-auth altoghether.


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