gpg-agent UI when waiting for smart card touch?

NIIBE Yutaka gniibe at
Tue Oct 24 08:15:08 CEST 2017

David Mandelberg <david at> wrote:
> I'm using gpg-agent with Yubikeys configured to require a physical touch 
> before performing operations. Is there any way to get gpg-agent to 
> display something on screen when it's waiting for me to touch the 
> Yubikey? (Otherwise, I sometimes don't realize it's waiting for 
> anything, and the operation times out.)

Some change in the protocol is required to implement this feature.

>From here, it's development thing.  Please skip reading, if you don't

Most easy change would be adding a new flag into Slot Status register
in the CCID specification 1.1.  See page 55 of the specification for
the Table 6.2-3 Slot Status register.

Say, using bit-2 as: waiting user interaction flag, when Time extension
is required.

With that flag, the device will be possible to notify scdaemon (then,
gpg-agent) to pop up dialog.

Since we already have a flag in the card feature (in OpenPGPcard
specification v3), we can distinguish if a card supports this feature or

That is just a idea.  I'll try with Gnuk Token, perhaps.

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