[pkg-gnupg-maint] Bug#939508: scdaemon: scdaemon does not share access with pcscd used by opensc

[Grizzard, Robert]

Package: scdaemon
Version: 2.2.17-3~bpo10+2
Severity: wishlist
Tags: newcomer patch upstream

Greetings,

I am attempting to use both the gpg and PIV functionaity of a Yubikey 5 
device, but scdaemon takes exclusive access.  This is the intended behavior 
according to the upstream maintainers [1].  A relevant upstream thread is [2], 
specifically the message [3].  

The desired functionality of shared access can be achieved by applying the 
patch used by the GPGTools project [4] (current commit as of this writing was 
5ca182f54b7b6cd635d1c0a4713953834489fdd9), though that patch does not list the 
license in place.

It is worth noting that application of the patch does not immediately override 
the exclusive access behavior of scdaemon, but instead the user must edit 
scdaemon.conf to include the line "shared-access" [5].  I have verified that 
building the debian package, with the patch installed within the debian/
patches/ directory, allows the desired shared access behavior of scdaemon 
after editing scdaemon.conf.

[1] https://dev.gnupg.org/T3267
[2] https://lists.gnupg.org/pipermail/gnupg-devel/2015-August/030242.html
[3] https://lists.gnupg.org/pipermail/gnupg-devel/2015-September/030264.html
[4] https://github.com/GPGTools/MacGPG2/blob/dev/patches/gnupg/
scdaemon_shared-access.patch
[5] https://wiki.archlinux.org/index.php/GnuPG#Shared_access_with_pcscd

Many thanks,
Robert Grizzard

-- System Information:
Debian Release: 10.0
  APT prefers stable-updates
  APT policy: (500, 'stable-updates'), (500, 'stable'), (100, 'unstable'), 
(10, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 5.2.0-0.bpo.2-amd64 (SMP w/4 CPU cores)
Kernel taint flags: TAINT_OOT_MODULE, TAINT_UNSIGNED_MODULE
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE= 
(charmap=UTF-8)
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages scdaemon depends on:
ii  gpg-agent      2.2.17-3~bpo10+2
ii  libassuan0     2.5.2-1
ii  libc6          2.28-10
ii  libgcrypt20    1.8.4-5
ii  libgpg-error0  1.35-1
ii  libksba8       1.3.5-2
ii  libnpth0       1.6-1
ii  libusb-1.0-0   2:1.0.22-2

scdaemon recommends no packages.e

scdaemon suggests no packages.

-- no debconf information