Communication protocol mismatch!

[fernvenue]

Hi, I'm using Yubico Authenticator on Debian Trixie/Testing, and pcscd service is running, but Yubico Authenticator still say that pcscd is not running, and I found out that there are some error messages in pcscd service:

Nov 07 14:42:18 OptiPlex pcscd[25770]: 00002907 ../src/winscard_svc.c:404:ContextThread() Communication protocol mismatch!
Nov 07 14:42:18 OptiPlex pcscd[25770]: 00000005 ../src/winscard_svc.c:406:ContextThread() Client protocol is 4:4
Nov 07 14:42:18 OptiPlex pcscd[25770]: 00000001 ../src/winscard_svc.c:408:ContextThread() Server protocol is 4:5

What should I do to fix this? Any help will be much appreciated :)

[ldet]

Experiencing the same, using the flatpack from flathub on debian trixie. Downgrading pcscd and libpcsclite1 to version 2.2.3-1 worked for me. Had to build those packages from source though.

The minor protocol version increased, and the pcsc-lite protocol versions must match exactly between the version included in the flatpack and the host. The upstream developer has an Blog article about that issue: https://blog.apdu.fr/posts/2022/02/accessing-smart-cards-from-inside/

[joelpurra]

The community flatpak on flathub mentions this as a packaging issue. The flatpak workaround is to use the beta flatpak.

NOTE: This (community) flatpak currently works only with distros that use version of pcsc-lite below 2.3.0. For distros that use version 2.3.0 and above use beta version of this flatpak. DON'T report this to Yubico.

• Failed to open smart card connection flathub/com.yubico.yubioath#90
• https://flathub.org/apps/com.yubico.yubioath
• com.yubico.yubioath does not work on Fedora 41 flathub/com.yubico.yubioath#101

Also successfully used ykman in a toolbox on Fedora F41 Silverblue; see linked issue.

[fernvenue]

Thanks for @ldet and @joelpurra, install beta flatpak works for me :)

[AdamVe]

I can confirm that this issue is with the Flatpak version of Yubico Authenticator, which requires a version of pcsc-lite that is protocol-compatible with the pcscd installed on the host. The official version, built by Yubico and available for download at Yubico Authenticator, works as expected on the current Debian Trixie. I’ve just tested it with the nightly build from 2024-12-09.