Monitoring queries to gpg-agent?

[Kristian Larsson]

Hello,

I would like to see the queries to gpg-agent that clients are 
sending. Like what key are they trying to access and whatever 
other information might be available as well.

A little background; I am using gpg-agent together with a Yubikey 
to securely store my GPG keys. In addition I've enabled so that 
whenever an authentication, sign or decryption request happens I 
must physically push the button on the Yubikey. It is very clear 
when I do ssh FOO and the Yubikey starts blinking that I need to 
push it and I can easily understand what query caused the Yubikey 
to start blinking (although I suppose there is a risk of someone 
using this opportunity to launch a query just prior and me 
thinking it is my ssh query will press the button).

I also have cron jobs that perform things, like running mbsync in 
the background to retrieve email and they in turn use GPG to 
decrypt the file containing the password. In this case I haven't 
interactively initiated the command but instead my Yubikey just 
starts blinking and I don't know why (although I can guess). I 
would like to be able to see what the current query to gpg-agent 
is.

Is there a way I can monitor and display the queries to gpg-agent 
so I can see what the current query is actually trying to do?

Kind regards,
   Kristian.

-- 
Kristian Larsson
kll at dev.terastrm.net