Ira,
Well I guess we just have broken systems here that use the same backend
directory service. And does that mean schemes such as OAUTH are broken
as well? I'm not advocating doing strong downstream or passing client
secrets along. All that is required in a fan out environment is the
child trust the parent. If it is a secure system it certainly won't
depend on the "requesting-user-name" and it will have a special
administrative role assigned to the parent printer. The initial printer
can authenticate the client. If access is permitted at the target
printer then the target printer has to tie into the same authorization
domain as the initial printer.
Pete
Peter Zehler
Xerox Research Center Webster
Email: Peter.Zehler at Xerox.com
Voice: (585) 265-8755
FAX: (585) 265-7441
US Mail: Peter Zehler
Xerox Corp.
800 Phillips Rd.
M/S 128-25E
Webster NY, 14580-9701
From: Ira McDonald [mailto:blueroofmusic at gmail.com]
Sent: Wednesday, November 16, 2011 1:08 PM
To: Michael Sweet; Ira McDonald
Cc: Zehler, Peter; ipp at pwg.org
Subject: Re: [IPP] Proposed errata for rfc3998
Hi,
OK - I'm mostly with Mike here.
Also, I'm pretty strongly *not* with Bill and Pete - the forwarding
Printers
OWN the downstream Jobs and have the Job submission and access
control and upstream notification receipt rights.
The original Job owner (on the cellphone) queries the *original* Job at
the first Printer (the Cloud Print Service, typically) to see the
rolled-up
and summarized results of the downstream Job processing.
Letting the original Job submitter cancel Jobs on way downstream
Printers
is a severe security violation that breaks any possible scheme of access
control.
Where would the authentication credentials come when the downstream
Jobs were created by the intervening Printers.
Because I assure you that the Printers *cannot* have the private key of
the
original Job owner and cannot keep doing strong downstream
authentication
in so-called proxy operations (and the assumption that simple username
and
password can just be sent forward out-of-band is hopelessly broken).
Cheers,
- Ira
Ira McDonald (Musician / Software Architect)
Chair - Linux Foundation Open Printing WG
Secretary - IEEE-ISTO Printer Working Group
Co-Chair - IEEE-ISTO PWG IPP WG
Co-Chair - TCG Trusted Mobility Solutions WG
Chair - TCG Embedded Systems Hardcopy SG
IETF Designated Expert - IPP & Printer MIB
Blue Roof Music/High North Inc
http://sites.google.com/site/blueroofmusic
<http://sites.google.com/site/blueroofmusic>
http://sites.google.com/site/highnorthinc
<http://sites.google.com/site/highnorthinc>
mailto:blueroofmusic at gmail.com
Winter 579 Park Place Saline, MI 48176 734-944-0094
Summer PO Box 221 Grand Marais, MI 49839 906-494-2434
On Wed, Nov 16, 2011 at 12:55 PM, Michael Sweet <msweet at apple.com>
wrote:
Pete,
My point about forwarding is that the mechanism for authenticating the
original-requesting-user-name and job-originating-user-name values over
IPP is undefined. How/why do the child printers implicitly trust
everything that is sent to them from the parent printer?
But again, the current wording makes original-requesting-user-name and
job-originating-user-name distinctly different:
original-requesting-user-name is the value that was supplied by the
client while job-originating-user-name is the most authenticated name.
Your proposed change would effectively make them the same, in which case
we should:
1. Remove forwarding of job-originating-user-name entirely,
2. Delete original-requesting-user-name entirely, or
3. Make original-requesting-user-name exclusively an operation attribute
and use it to pass the forwarded job-originating-user-name value in the
fan-out case (this would, IMHO, be the sanest approach).
On Nov 16, 2011, at 9:23 AM, Zehler, Peter wrote:
Mike,
The semantics are limited to Job forwarding systems of printers
(i.e. IPP Fan out and fan in). On the first system the Job's
"original-job-requesting-user-name" and "job-originating-user-name" are
populated with the same value. Per rfc2911 that value is the most
authenticated printable name that it can obtain from the authentication
service over which the IPP operation was received. Only if such is not
available, does the Printer object use the value supplied by the client
in the "requesting-user-name". On the next hop is where things diverge.
The upstream printer uses its own identity in the
"requesting-user-name" operational attribute. It also passes along the
"original-requesting-user-name" as an operational attribute. The
downstream printer uses the "requesting-user-name", or the identity
obtained from a trusted protocol layer, to insure the request is from a
configured upstream printer. The downstream printer then copies over
the "original-job-requesting-user-name" operational attribute to the job
object AND to the job object's "job-originating-user-name". In other
words the child job is owned by the initial submitting user throughout
the chain and not by the immediate parent (i.e. IPP Printers).
Pete
Peter Zehler
Xerox Research Center Webster
Email: Peter.Zehler at Xerox.com
Voice: (585) 265-8755 <tel:%28585%29%20265-8755>
FAX: (585) 265-7441 <tel:%28585%29%20265-7441>
US Mail: Peter Zehler
Xerox Corp.
800 Phillips Rd.
M/S 128-25E
Webster NY, 14580-9701
From: Michael Sweet [mailto:msweet at apple.com]
Sent: Wednesday, November 16, 2011 10:47 AM
To: Zehler, Peter
Cc: ipp at pwg.org
Subject: Re: [IPP] Proposed errata for rfc3998
Pete,
If we make this change, then what is the difference between
original-requesting-user-name and job-originating-user-name?
Section 10.8.4 (re)defines job-originating-user-name as the
authenticated original user and whose value is supposed to be forwarded
by each client unchanged... (something I am not 100% happy with since
there is no provision for it in an IPP job submission)
Seems like the original intent was for
original-requesting-user-name to be the unauthenticated value.
(and now I go off to add some text for this to JPS3 for
job-originating-user-uri...)
On Nov 16, 2011, at 3:17 AM, Zehler, Peter wrote:
Please substitute "section 10.8.3 of rfc3998" for "section
10.8.8 of rfc3998" below.
Peter Zehler
Xerox Research Center Webster
Email: Peter.Zehler at Xerox.com
Voice: (585) 265-8755 <tel:%28585%29%20265-8755>
FAX: (585) 265-7441 <tel:%28585%29%20265-7441>
US Mail: Peter Zehler
Xerox Corp.
800 Phillips Rd.
M/S 128-25E
Webster NY, 14580-9701
From: ipp-bounces at pwg.org [mailto:ipp-bounces at pwg.org] On Behalf
Of Zehler, Peter
Sent: Wednesday, November 16, 2011 6:13 AM
To: IPP at pwg.org
Subject: [IPP] Proposed errata for rfc3998
All,
Section 10.8.2 covering "original-requesting-user-name" is a bit
misleading. The issue is that the Job owner is not always the same as
the "requesting-user-name". When forwarding jobs from one printer to
another the "original-requesting-user-name" is the most authenticated
printable name that can be obtained. As stated in section 10.8.8 of
rfc3998: "The "job-originating-user-name" Job Description attribute
(see [RFC2911], section 4.3.6) remains as the authenticated original
user". This is inconsistent with section 10.8.2 as currently written.
Below is my proposed change to section 10.8.2.
Original:
10.8.2. original-requesting-user-name (name(MAX)) Operation and
Job
Description Attribute
The operation attribute containing the user name of the
original
user; i.e., corresponding to the "requesting-user-name"
operation
attribute (see [RFC2911], section 3.2.1.1) that the original
client
supplied to the first Printer object. The Printer copies the
"original-requesting-user-name" operation attribute to the
corresponding Job Description attribute.
Corrected:
10.8.2. original-requesting-user-name (name(MAX)) Operation and
Job
Description Attribute
The operation attribute containing the user name of the
original
user; i.e., corresponding to the "job-originating-user-name"
Job
attribute (see [RFC2911], section 4.3.6) that identifies the
Job
owner on the first Printer object. The Printer copies the
"original-requesting-user-name" operation attribute to the
corresponding Job Description attribute.
Peter Zehler
Xerox Research Center Webster
Email: Peter.Zehler at Xerox.com <mailto:Peter.Zehler at Xerox.com>
Voice: (585) 265-8755 <tel:%28585%29%20265-8755>
FAX: (585) 265-7441 <tel:%28585%29%20265-7441>
US Mail: Peter Zehler
Xerox Corp.
800 Phillips Rd.
M/S 128-25E
Webster NY, 14580-9701
--
This message has been scanned for viruses and
dangerous content by MailScanner <http://www.mailscanner.info/>
, and is
believed to be clean.
--
This message has been scanned for viruses and
dangerous content by MailScanner <http://www.mailscanner.info/>
, and is
believed to be clean.
_______________________________________________
ipp mailing list
ipp at pwg.orghttps://www.pwg.org/mailman/listinfo/ipp
________________________________________________________________________
Michael Sweet, Senior Printing System Engineer, PWG Chair
________________________________________________________________________
Michael Sweet, Senior Printing System Engineer, PWG Chair
--
This message has been scanned for viruses and
dangerous content by MailScanner <http://www.mailscanner.info/> , and is
believed to be clean.
_______________________________________________
ipp mailing list
ipp at pwg.orghttps://www.pwg.org/mailman/listinfo/ipp
--
This message has been scanned for viruses and
dangerous content by MailScanner, and is
believed to be clean.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.pwg.org/pipermail/ipp/attachments/20111116/575a25e3/attachment-0001.html>