Bug 357954

Summary:	Sometimes get "unlocking failed" error when using yubikey with static password
Product:	[Unmaintained] kscreenlocker	Reporter:	cnmaps
Component:	general	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED WORKSFORME
Severity:	minor	CC:	bjoernv, bshah, hhgebel, mgraesslin
Priority:	NOR
Version First Reported In:	5.5.1
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description cnmaps 2016-01-13 22:17:46 UTC

While testing a Yubikey configured with a static password (press a button and the password is automatically typed) over 55 characters, I found that a unlocking the lock screen fails about 50% of the time (10 failures in 20 attempts).

This appears to be due to the Yubikey entering characters very quickly (over 55 characters in 1 second) that some characters in the password are not typed into the field.

This has never happened when entering the password from the desktop or when logging in for the first time after a reboot.

If I copy the password when on the desktop, lock the screen, and paste it into the password field, it never fails.

If I hit Enter after getting an "unlocking failed" error without clearing the field and entering it again, it always fails.

While testing, I noticed that this seems to happen in streaks - with it failing multiple times in a row, then it being ok for several attempts in a row.

Here's the pattern for 20 trials:

2 successful
4 failures
4 successful
3 failures
4 successful
3 failures

Reproducible: Sometimes

Steps to Reproduce:
1. Lock the desktop
2. Use a Yubikey or (maybe) something else that quickly enters a long password to log back in




https://en.wikipedia.org/wiki/YubiKey

Comment 1 cnmaps 2016-01-13 23:54:35 UTC

Using Manjaro Linux.

Comment 2 Martin Flöser 2016-01-14 07:01:08 UTC

I don't have such a device so it's difficult for me to reproduce.

Can you please invoke the greeter process manually and check whether it works there?
It's in /usr/lib/<arch>/libexec/kscreenlocker_greet and please run it with --testing.

If it works there we have a problem in the communication between the greeter and the daemon.

Comment 3 cnmaps 2016-01-17 00:56:52 UTC

It works from the greeter - 20 trials, no failures.

Comment 4 Martin Flöser 2016-01-17 16:54:50 UTC

> It works from the greeter - 20 trials, no failures.

Thanks for testing! I have an idea what might be a problem, I'll try to 
hack a possible patch together.

Comment 5 cnmaps 2016-01-18 18:09:26 UTC

Thanks for looking into it!

Glad I could help.

Comment 6 Harry Henry Gebel 2016-03-11 02:00:57 UTC

I have the same problem on Funtoo Linux. I also got it to work 100% by running the greeter by itself with the '---testing' parameter. I have been able to temporarily work around it by setting the Yubikey to output the password slower (20ms extra delay between keypresses) but it would be nice to have this fixed so I could use it at full speed.

Comment 7 Justin Zobel 2022-10-24 00:46:31 UTC

Thank you for reporting this bug in KDE software. As it has been a while since this issue was reported, can we please ask you to see if you can reproduce the issue with a recent software version?

If you can reproduce the issue, please change the status to "REPORTED" when replying. Thank you!

Comment 8 Bug Janitor Service 2022-11-08 05:10:04 UTC

Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please
mark the bug as REPORTED so that the KDE team knows that the bug is
ready to be confirmed.

Thank you for helping us make KDE software even better for everyone!

Comment 9 Bug Janitor Service 2022-11-23 05:16:30 UTC

This bug has been in NEEDSINFO status with no change for at least
30 days. The bug is now closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

Thank you for helping us make KDE software even better for everyone!