+++ This bug was initially created as a clone of Bug #1169988 +++
This problem still exists exactly as described in Fedora 21.  I will try to test with Fedora 24 once it's GA.

Description of problem:

When a user with a registered fingerprint attempts to use sudo, it prompts for the user to swipe their fingerprint. To instead use a password, the user must wait 30 seconds for the fallback to password authentication. This differs from gdm behaviour, where fingerprint and password are accepted in parallel, authenticating with whichever is received.

The fingerprint timeout wait does not respond to ^C, like a password prompt does.

Attempting to bypass the prompt with <ENTER> also does not work. However, after the fingerprint timeout, that <ENTER> keystroke is used as a password attempt, thus causing a failed password attempt, starting a new authentication attempt and another 30 second wait for a fingerprint.

User input is not masked while waiting for the fingerprint timeout to occur, so user entry is echoed to the terminal. If the user types their password into sudo without noticing the "fingerprint" instead of a "password" message, their password is echoed to the terminal. That password will actually authenticate once the fingerprint timeout expires (as above with <ENTER>, input is passed to the password prompt).

Additionally, I use my laptop while docked, and Fedora generally handles everything (monitor, etc) correctly. However, the built-in fingerprint reader is inaccessible when the lid is closed. gdm handles this situation fine, as it accepts password or fingerprint in parallel. However, sudo still waits for input from my inaccessible fingerprint reader.


Version-Release number of selected component (if applicable):

    $ yum list installed \*fprint\* sudo
    Installed Packages
    fprintd.x86_64                        0.5.1-3.fc21                     installed
    fprintd-pam.x86_64                    0.5.1-3.fc21                     installed
    libfprint.x86_64                      0.5.1-4.fc21                     installed
    sudo.x86_64                           1.8.8-7.fc21                     installed


How reproducible:

    Every time sudo requires authentication.


Steps to Reproduce:

1. Have a fingerprint registered
2. $ sudo date
3. Don't use fingerprint for authentication


Actual results:

* Wait 30 seconds for password fallback
* Wait 30 seconds for fingerprint, even if reader is inaccessible (Lid closed)
* Input during 30 second timeout not masked
* Input during 30 second timeout not cleared from buffer before accepting password


Expected results:

* Accept fingerprint OR password in parallel (like GDM)

OR

* Allow fingerprint wait message to be bypassed with CTRL-C
* Clear input buffer before accepting a password

Additional info:

--- Additional comment from Fedora End Of Life on 2015-11-04 09:48:41 EST ---

This message is a reminder that Fedora 21 is nearing its end of life.
Approximately 4 (four) weeks from now Fedora will stop maintaining
and issuing updates for Fedora 21. It is Fedora's policy to close all
bug reports from releases that are no longer maintained. At that time
this bug will be closed as EOL if it remains open with a Fedora  'version'
of '21'.

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, simply change the 'version' 
to a later Fedora version.

Thank you for reporting this issue and we are sorry that we were not 
able to fix it before Fedora 21 is end of life. If you would still like 
to see this bug fixed and are able to reproduce it against a later version 
of Fedora, you are encouraged  change the 'version' to a later Fedora 
version prior this bug is closed as described in the policy above.

Although we aim to fix as many bugs as possible during every release's 
lifetime, sometimes those efforts are overtaken by events. Often a 
more recent Fedora release includes newer upstream software that fixes 
bugs or makes them obsolete.

--- Additional comment from Fedora End Of Life on 2015-12-02 00:24:28 EST ---

Fedora 21 changed to end-of-life (EOL) status on 2015-12-01. Fedora 21 is
no longer maintained, which means that it will not receive any further
security or bug fix updates. As a result we are closing this bug.

If you can reproduce this bug against a currently maintained version of
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bug.

Thank you for reporting this bug and we are sorry it could not be fixed.