gpg-agent: how to limit the passphrase cache retention time

Question

I'm using Thunderbird/Enigmail, and the plugin tells me that the process in charge of the passphrase cache is gpg-agent. The retention time of the passphrase is too long for me (possibly, the entire session). I would like to make it shorter, but so far I have failed to do so.

gpg-agent seems to be run without a default-cache-ttl argument (according to ps), so according to the manual it should use the default value, 600 seconds. It's obviously not the case. It should also use the default value for max_cache_ttl (2 hours), but it's not the case either.

I tried to create a gpg-agent.conf file in my ~/.gnupg with a custom value for default-cache-ttl, but it seems to have no effect (I have restarted my session in order to restart gpg-agent).

Either I'm trying to tweak the wrong process, or it doesn't behave according to its specifications, or there is something I don't understand. How can I efficiently shorten this passphrase retention time?

Answer 1

Let me begin by saying I had the exact same issue...

I found and post a solution for configuring GPG passphrase cache retention time on Ubuntu on another question.

There is however a minor issue with the second method (disabling the GPG component of the GnomeKeyring) and Thunderbird/Enigmail: when the cache is cleared, you may get a message saying the password is wrong before any actual prompt for it; just click OK (to retry) and you will get the prompt.