IPP> 4 significant proposed increases in conforman ce requirem ents for the IPP Document object spec

IPP> 4 significant proposed increases in conforman ce requirem ents for the IPP Document object spec

Mike Sweet mike at easysw.com
Sun Apr 20 17:18:24 EDT 2003


McDonald, Ira wrote:
> ...
> Is there any practical reason why PSI can't just require stricter
> requirements than the basic IPP mapping?  It seems idiotic to
> require print-by-reference for IPP whose goals are different than
> PSI.
> 
> 
> <ira> _my_ goal is full-bandwidth application gateways between
> IPP and PSI.  Everywhere that IPP doesn't have a feature at all
> (the out-of-band push in PSI's AddDocumentByPush) or has made a
> feature optional (PSI's AddDocumentByReference), the gateway will
> fail entirely.
> 
> Note, PSI _is_ sending (over a TLS-secured channel) whatever
> username and password or certificate necessary to do the SMTP,
> IMAP, HTTPS, or whatever connection for the AddDocumentByReference,
> from the client embedded in the PSI Print Service or Target Device.

I will repeat this if it wasn't obvious from my example - passing
authentication info does not solve the print-by-reference problem.
Cookies, host-based access control, and other implementation-
specific issues on the remote server end are not handled, and that
means that print-by-reference stops working.

While I understand that we cannot guarantee that every URI using
a supported scheme can be printed, I do not see the point of
requiring print-by-reference when we *know* that many common use
cases will fail.

> If this is security nightmare for IPP, then the same applies to
> PSI - why is it so hard if the Print Service simply impersonates
> the end user?  (I know this can't work if the end user's TLS

Because the print service cannot always impersonate the end-user.

> ...
> <ira> Well, print by reference is the main design center of PSI, so
> if it will hurt adoption of IPP Document objects, then it will
> equally hurt PSI adoption.  Do you think PSI is in trouble??
> </ira>

I personally never saw the point of PSI, even for things like web
pads.  XHTML-Print + IPP is enough to support printing of web pages
directly without print-by-reference (client can send a copy of the
web page and images, which it already has in memory...), and PDF
and other common web formats are well supported the same way.

-- 
______________________________________________________________________
Michael Sweet, Easy Software Products                  mike at easysw.com
Printing Software for UNIX                       http://www.easysw.com




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