unable to enter gpg passphrase via graphical helper due to pinentry crashing

[James Hunt]

I have the following setup in my ~/.profile:

    export SSH_ASKPASS=/usr/lib/openssh/gnome-ssh-askpass
    eval `keychain --eval ssh-key-1 ssh-key-2 gpg-key-1 gpg-key-2`

When I login via lightdm, I am then prompted to enter passwords/passphrases with a graphical input box. However recently,
after successfully handling my ssh keys, when I attempt to enter a pass-phrase into the gpg unlock box, the input box disallows all input. The only options is to press the cancel button with the mouse and login on a tty. The problem appears to be caused by pinentry (pinentry-gtk2) since dmesg shows:

[ 145.876384] pinentry[3858]: segfault at c ip b691a1e6 sp bfd1d238 error 4 in libncurses.so.5.9[b6912000+20000]
[ 148.043642] pinentry[3867]: segfault at c ip b69c61e6 sp bfead1a8 error 4 in libncurses.so.5.9[b69be000+20000]

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: pinentry-gtk2 0.8.1-1ubuntu1
ProcVersionSignature: Ubuntu 3.2.0-12.20-generic-pae 3.2.2
Uname: Linux 3.2.0-12-generic-pae i686
NonfreeKernelModules: nvidia
ApportVersion: 1.91-0ubuntu1
Architecture: i386
Date: Wed Feb 1 08:51:12 2012
InstallationMedia: Ubuntu 10.10 "Maverick Meerkat" - Release i386 (20101007)
ProcEnviron:
 PATH=(custom, user)
 LANG=en_GB.UTF-8
 SHELL=/bin/bash
SourcePackage: pinentry
UpgradeStatus: Upgraded to precise on 2012-01-12 (19 days ago)

[James Hunt (jamesodhunt)]

I should point out that when logging in via a tty, keychain kicks in and prompts for the gpg pass-phrases (using curses) and this is successful. The dmesg segfaults do appear to be caused by the graphical prompter which is linked to libncurses.

On my system, pinentry is linked to the qt4 variant (which seems somewhat odd?):

$ ls -l /etc/alternatives/pinentry
lrwxrwxrwx 1 root root 21 Jan 28 20:27 /etc/alternatives/pinentry -> /usr/bin/pinentry-qt4
$

[James Hunt (jamesodhunt)]

Running the following and selecting "/usr/bin/pinentry-gtk-2" works around the problem with the qt version of pinentry:

  sudo update-alternatives --config pinentry

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.