[Gnuk-users] gpg: signing failed: Zero prefix in S-expression

[NIIBE Yutaka]

On 03/25/2015 07:39 AM, Jonathan Schleifer wrote:
> So, before, it did work again if I did gpg2 --card-edit and then
> passwd (and cancel), but either this was just a coincidence, or this
> trick stopped working now. It seems to happen especially often when
> signing Git commits. I have no idea why. I can rarely sign two Git
> commits in a row and even for the first one to work, a lot of
> killing gpg-agent and re-plugging the Gnuk is involved.

Could you please give me debug output of scdeamon?

------------------------------ .gnupg/scdaemon.conf
debug-level guru
debug-all
log-file /tmp/scd.log
# debug-ccid-driver
------------------------------

Also, you could try not-using PC/SC service, too.

SCDaemon has two way to access smartcard reader or token.  One is
PC/SC service and another using directry access by libusb (GnuPG's
internal CCID driver).

IIUC, people use Gnuk Token with PC/SC service on MacOS.

I don't know how to configure MacOS for the USB device permission,
but SCDaemon with GnuPG's internal CCID driver is better, in general,
or it's better to figure out problem for debugging.

For GnuPG's internal CCID driver, please enable debug-ccid-driver in
scdaemon.conf (by removing #).
--