How can I adjust the default passphrase caching duration for GPG/PGP/SSH keys?

Question

As far as I know, gnome-keyring-daemon caches passphrases for keys by default until I log out. I would like to set the default to something like "cache for 10 minutes". How can I do that in Ubuntu 12.04 Precise?

Thanks a lot!

Solution

• Lauch dconf-editor.
• Navigate to desktop - gnome - crypto - cache.
• change gpg-cache-method to idle or timeout.
• change gpg-cache-ttl to the number of seconds you want the passphrase to be cached.
• Restart the gnome-keyring daemon $ gnome-keyring-daemon -r

idle means that the timer is reset each time you use the key before timeout is reached. timeout means that simply the time elapsed since entering the passphrase is considered.

This only works for GPG-keys. Passphrases for SSH-keys are still cached until the end of the session. IMHO this is a bug.

Comments

[Admin]

I found related options in ´gsettings´ under ´org.gnome.crypto.cache´. Unfortunately these do not seem to have any effect. Probably this is due to this bug for which the fixes apparently were never merged to ubuntu (bugzilla.gnome.org/show_bug.cgi?id=681081)

[Admin]

OK, the last comment is only true for SSH-keys. For GPG the settings work as expected.

[Uwe Heim]

I did what you suggested and it made no difference. The system remembers the passphrase regardless and decryption follows. This is a serious security issue. I am surprised nobody has raised a red flag.

[Linter]

I'm struggling with this problem under Ubuntu 18.03. I used dconf-editor to change to timeout and use 1 second. I reset the keyring and immediately after I had to use the password for my PGP key. However, once entered, the password gets cached again. It survives a reboot/logout. Very frustrating!

[Flux]

If not mistaken, the command line equivalent is: gsettings set org.gnome.crypto.cache gpg-cache-method 'timeout', gsettings set org.gnome.crypto.cache gpg-cache-ttl 300, gnome-keyring-daemon -r.