[cups] SSL in cups 2.3.3op2

[Douglas Kosovic]

Hi Mark,

> Upgraded to Bullseye on Raspberry Pi 3B+  from Stretch. Far too many 
> issues with CUPS 2.3.3op2.

Okay, I have CUPS 2.3.3op2-3 on a Raspberry Pi, added a print queue, then tried with Android 10, but had no success finding the print queue.

'avahi-browse --all -r' wasn't listing any mDNS advertisement for the print queue, so I added the following line to /etc/cups/cupsd.conf :

BrowseDNSSDSubTypes _cups,_universal,_print

iOS was then able to find the print queue, but still no luck with Android. The output of 'avahi-browse --all -r' doesn't have mopria-certified in the mDNS advertisement for the print queue which I suspect is the problem.

When I get home tonight, I'm thinking of doing a backport build of CUPS 2.4.7-1 from Debian Sid to see if things work. With CUPS 2.4 it definitely mDNS advertises mopria-certified for the print queues.

From the following page, I get the impression even with the default Android Print Service that they mention, it only works with printers that advertise they are mopria-certified :
  https://mopria.org/androidfaq


> If I manually enter the printer URL in cups client for android with 
> "https:" it does not print and sometimes crashes android client.

I suspect the Android CUPS client you are referring to is the following :
https://github.com/BenoitDuffez/AndroidCupsPrint
https://play.google.com/store/apps/details?id=io.github.benoitduffez.cupsprint

That Android CUPS client has nothing to do with the OpenPrinting CUPS and uses cups4j which is written in Java. I suspect the TLS/SSL certificate issues you are having are because of that client.




Cheers,
Doug