That's pretty much my opinion. Printers have real and significant
costs associated with their use, so some kind of authentication is needed.
> So, would it be acceptable for IPP to drop TLS and require that all IPP
> clients and servers support HTTP/1.1 digest authentication?
Not without explaining how this will scale to IPP's anticipated use.
The problem is that IPP wants print servers all over the world
to be usable from anywhere by any IPP client. Shared secrets
don't even scale to medium size workgroups, much less user
populations of the size of the Internet.
Most printers aren't suitable for providing service to all comers
anyway, so it doesn't make sense to require all printers to support
scalable authentication. But you clearly want clients to be able
to print to any of: local printers, printers in their office/workgroup/
building, and printers in Kinko's and Sir Speedy's and other service
providers that will be out there. Wasn't this a primary goal of IPP?
So if IPP wants clear direction about what's likely to get past IESG,
I'll say that clients MUST support both digest and TLS, and servers
MUST support digest and MAY support TLS.
The alternative is for IPP to convince IESG that digest authentication
alone really is adequate for a wide variety of printer authentication
scenarios. I won't claim that it cannot be done, but offhand, I don't
see how to do this.
Keith