I don't anymore think that it makes sense to fix it. Further there is no cache for PINs; that is entirely up to the card.

This was most likely a (chipcard) hardware issue. It went away after polishing the contact pads for a bit. Possibly my laptop reader applies more force...

Thanks so much your helps.
With new version 3.1.6, I can generate key on Kleopatra tool and use key stored in smartcard.

There was indeed a problem. With a test card I could reproduce the issue and fix it.

Thanks for fixing that.

That's my badness. In wait_child_thread, assuan_release may cause thread context switch to agent_reset_scd which accesses scd_local_list; This access should be serialized.
And... in start_scd, calling unlock_scd should be after unlocking start_scd_lock.

Does not happen in 2.2. Additional requirement to test this bug in master: Another connection to the scdaemon must be open. For example running scute or, easier, call "gpg --card-edit" and keep it open.

Gnuk implements the feature, and newer GnuPG shows a dialog to request pushing the ack button.

Interaction will be something like this:

Priority is high, because Gnuk Token requires this feature for testing its implementation.

Thank you for the clarification. For now, I'll modify our implementation to use shorter length representation and close this bug as Invalid.
However, I'm still not convinced that using hard-coded arguments is the right way to handle requests. I'll do some more testing and if I discover a legitimate use-case that requires long APDUs, I'll reopen the issue.

Thanks for the information.

In our implementation, DO 0x6E contains:

I don't understand the reason why 0x6E (Application Related Data) can be so long. What OpenPGP card implementation do you have?

Here is a sequence of operations/commands that permits to setup or update KDF-DO and align PIN codes accordingly:

Now there it gets complicated. According to the card software author in 3.3 and even 2.2 there is a fix. BUT there was a small amount of cards already created in 3.3 without the fix. Nobody ever told my how to diferentiate them.
There is no Version 3.3.1 you can by - it is only 3.3. So you can buy one and hope you have a good one.
At least this is my understanding.

Does v3.3.1 fix this? (The release notes for it seem to imply that's not the case.)

@nitroalex Perhaps, creating new ticker is better for this topic.
In the current OpenPGP card specification, there is no way for an application (except having a list of card implementation information) to know wich algo and which curve is supported or not.
So, what an application does is try and error.
I don't like this situation, but I don't know how we can modify the specification.

Well, I surely would agree (and this is only a proposal anyway), but my point here is, that OpenPGP Card does not support Curve 25519, so that one *have to* choose between those other two. Considering me a tinfoil hat person, I would rather not choose NIST, as many others wouldn't too.

Neither Brainpool nor NIST curves make any sense unless there is an organizational policy requirement. Thus the --expert requirement is the Right Thing (tm).

works just fine, thx!

For the situation where PINs are not factory setting, given the specification, I don't know how to achieve "to align all PWs and the KDF-DO with correct values"; It might depend on card's implementation.

You are right about the fact that multiple steps could result in unusable cards in case of power down before all commands have been issued. Nevertheless, in practice, these commands would involve very few treatments on the token (i.e. no cryptographic operation or heavy data transfer) and it should really not take long to complete the three steps (admin PIN update, user PIN update, KDF-DO update).

Workaround is implemented in 2.2.6.

Fixed in 2.2.6.

My interpretation of the specification is different.
By requiring the condition of setting KDF-DO (it is only valid to setup KDF-DO when PINs are factory setting), Gnuk works well with current "kdf-setup".
If the procedure of setting KDF-DO includes multiple steps with KDF-DO update and PIN update, there is a risk of power down which results unusable card.

Yes, I meant the document. Please note that I am also one of users of the specification (for GnuPG, and for Gnuk Token). I am not defending, but try to explain the current situation.

I was referring to this document:

You describe it as 'manual'. AFAIK, it's the specification for the functionality.
I have an experience implementing the functionality, following the specification.
And my own implementation does always return 512 bytes for RSA-4096. So, I could support your opinion.

I realized that KDF support may be incompatible to Gnuk's feature of "admin-less" mode.
I'm going to implement compatible KDF support to Gnuk; That is, KDF data which only has a single salt.
In this case, all KDF calculation (user, reset-code, and admin) is done with the single salt.
With single salt, admin-less mode can work with no problem.

Furthermore, I changed to have an explicit command: key-attr

I changed the interaction so that user can specify RSA or ECC, then when it's for ECC, specifying curve.

2.2.6 will have this feature in --card-edit, as kdf-setup. Please test.

For factory-reset, rG2c85e202bc30: scd: Better user interaction for factory-reset. fixed the issue.

Hallo Werner,

I've contacted Yubico to review this ticket.

Hi, that works as advertised. If this is the best solution yubikey permits us I am ok with it.

I put an entry: https://wiki.gnupg.org/SmartCard#Known_problem_of_Yubikey

After resume, because resume is not detected, some user interaction is required to cause an error.
gpg --card-status (which will only show partial information) is enough. Or, ssh failure. After failure, scdaemon reconnects the token.
Then, you can use it again without plug-off/plug-in.

Thanks a lot for pointers and suggestion.
Well, the problem of Yubikey itself cannot be solved by others, we can put some workaround for the error recovery.
So, this is another try of mine to improve error recovery.

• There was same problem in yubico-piv-tool and it was solved by detecting error state (0x80100068) and reconnecting to the smart card if necessary [1]
• There is also a thread in OpenSC discussing this issue [2] and relevant PRs [3]
• I also found a project that claims to fix SCARD_W_RESET_CARD by disabling exclusive access to the card before asking for PIN (and then they enable exclusive access again) [4]

New cards will come with a fix. I am not sure whether a production run has yet been done, though.

Part of the problem is Yubikey side, I suppose. (Because my implementation of Gnuk Token has no problem for suspend/resume if it's in-use.)

Again, thanks a lot for your testing. The log said: The code I added cannot detect the event of suspend/resume.
It seems that there is no way to recover from suspend/resume for Yubikey.

Hello again,

Yeah, this is better, we got apdu_get_status => sw=0x0 status=7 and I can auth with this version as usual. After sleep-wake cycle it would however fail with pcsc_transmit failed: reset card (0x80100068). Logs attached.

Thanks a lot for your testing. So, apparently, the PC/SC behavior is different between GNU/Linux and Windows.
Thus, I pushed another change: rG1e27c0e04cd3: scd: More fix with PC/SC for Windows.. Please test this. (Both of previous version and this version work well on GNU/Linux for operations not including suspend/resume with Yubikey and Gnuk Token, while my Yubikey with PC/SC doesn't work well for suspend/resume.)

Thanks, this version of scdaemon executes.

Sorry, my build was not good even if it's for x86_64 (I used development version of libassuan, etc.).

I realized that: once KDF-DO is written to smartcard/token, factory-reset command won't work because it assumes standard PIN format than hashed.

Sorry again. My script was still wrong (didn't work).

It doesn't work because I did mistake for the salt of reset code, it should be 8-byte instead of 4-byte.
Here is a fixed version, which I tested with Gnuk 1.2.8:

@gniibe it seems the patched scdaemon.exe is 64 bit executable and it requires libassuan6-0.dll. However I got installed 32 bit version of gpg that only has incompatible libassuan-0.dll. I scanned whole computer for the missing lib, skimmed your ftp for 64 bit binaries and looked into gpg4win installer to find it, but no luck. There is also libassuan github repo, but I would like to avoid building the dll myself; there would probably be more than one dll to build anyway.

If possible, please try with this (patched version of scdaemon):

Something like this script should be implemented by gpg frontend:

I realized that suspend/resume is not supported yet on GNU/Linux: https://anonscm.debian.org/cgit/pcsclite/PCSC.git/tree/TODO#n7
So, I can't test myself.
Here is an attempt to improve:

It looks like SCardGetStatusChange doesn't return failure after wake up.
Here, what we need is catching the event of wake up, which requires reset of the card.
I think that we can check by the dwEventState field.
I'll try on GNU/Linux environment, then ask you to try.

@werner there had to be some mix up, as the log snippet is not mine.

This seems to be the relevant part of the log:

2017-11-18 07:45:15 scdaemon[8918] DBG: ccid-driver: CCID: card inactive/removed
2017-11-18 07:45:15 scdaemon[8918] ccid open error: skip
2017-11-18 07:45:15 scdaemon[8918] pcsc_establish_context failed: no service (0x8010001d)
2017-11-18 07:45:15 scdaemon[8918] DBG: ccid-driver: CCID: interrupt callback 0
2017-11-18 07:45:15 scdaemon[8918] DBG: ccid-driver: CCID: card removed