Hi Mirja,
you are right in the sense that (a) if all previous evaluations have
been performed without a failure, and (b) if no revocation occurred (or
(c) a previous revocation has cleaned up all further delegation
entries), then the write procedure can rely on the single delegation
entry that matches the current user name of the writer.
However, this includes several "ifs". For instance, if cleanup of the
delegation list has not been completed at the time of granting write
access, errors in the trust chain may occur. This could introduce
unwanted attack surface.
Our rationale behind designing this complete, self-contained procedure
was (a) writing an ACL list is not a frequent operation (so complexity
is not the major concern), and (b) keeping all operations simple,
robust, and of minimal dependence w.r.t. each other.
That's why it's like that.
Cheers,
Thomas
On 31.10.2016 15:06, Mirja Kuehlewind wrote:
Mirja Kühlewind has entered the following ballot position for
draft-ietf-p2psip-share-09: No Objection
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----------------------------------------------------------------------
COMMENT:
----------------------------------------------------------------------
Quick questions on sec 6.3. (Validating Write Access through an ACL):
Do I really need to validate the authorization chain in the ACL every
time I give access to a resource? Wouldn't I rather validate the ACL when
it's modified and then simply assume that it is sufficient that I have an
entry in the ACL to provide access?
--
Prof. Dr. Thomas C. Schmidt
° Hamburg University of Applied Sciences Berliner Tor 7 °
° Dept. Informatik, Internet Technologies Group 20099 Hamburg, Germany °
° http://www.haw-hamburg.de/inet Fon: +49-40-42875-8452 °
° http://www.informatik.haw-hamburg.de/~schmidt Fax: +49-40-42875-8409 °
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