I forgot that we have LOCK and UNLOCK commands in scdaemon. This was implemented around 2005 but there are no more users in gpg meanwhile.

I have tested this with Kleopatra. The good news is that SCD GETATTR $DISPSERIALNO now works for the piv app even if the openpgp app is enabled.

SCD commands:

• SERIALNO
  • returns app specific serialno
• LEARN
  • returns canonical serialno

The action to switch to the "Smartcard management" still lacks an icon. In the old KDE icon theme Oxygen there was an icon ("secure-card"), but the new Breeze icon theme lacks this icon. I have requested an icon for this for the Breeze theme. See https://bugs.kde.org/show_bug.cgi?id=428278.

Pushed the change.

I created this patch D509: Yubikey supports two (or more) apps, serial number problem.

My sks keyserver is in Linux Ubuntu 18.04 LTS. As a client I'm using windows 10 and gpg4win is 3.1.13.

Hmm, interesting. I'm using the Back button all of the time to get back to the certificate list from the smartcard manager. Might be a Windows-only bug.

Are you on Windows or Linux? What version of Kleopatra or Gpg4win are you using?

But changing just the displayed S/N should not disturb anything.

No, the above patch makes OpenPGP app stop working.

(I don't know well about Yubikey specific serial number.)

The user is asked for a passphrase only if the key has a passphrase. I am still in favor of making a passphrase optional and then we need an extra dialog. Better safe than sorry. Those who have a workflow which includes the export of the secret key can still use the command line.

I suggest to also change the option to "Backup Secret Key..." (i.e. singular instead of plural) because the corresponding action does not support the export of multiple secret keys.

This doesn't help. I think that's because after

flush_cached_data (app, dobj->tag);

do_writecert does

do_readkey (...)

which fills the cache again.

Caching issue. do_writecert in app-piv flushes the cache but may be the wrong DO. Can you try to

Kleopatra does now support using multiple smartcards with multiple apps concurrently (at least as far as the backend scdaemon supports this). Only tested with master of everything so far.

I think you have missed the Key Pair Creation Wizard:

Create a personal X.509 key pair and certification request

kleopatra/src/newcertificatewizard/chooseprotocolpage.ui

I have added a workaround to Kleopatra: rKLEOPATRA57cf71b043d198f85270eb3b8782de6277b8b889