Hi Mirja,
On 04.11.2016 11:20, Mirja Kuehlewind (IETF) wrote:
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.
Could you document this attack surface in the doc…?
Mhmm, if complete validation is performed (as requested by the
document), the attack surface is not there. As pointed out in 6.2, valid
revocation is a single operation. Otherwise there would be probably a
lengthy discussion on "how can I disturb a peer" (DoS, malicious
requests, ...)
We would rather be robust and skip this set of options ;)
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.
Don’t you have to do the check every time you check write access for a shared
resource? That can be much more often.
As of Section 6.5, an accessing peer can cache (the list and the
validation). So it can memorize previous checks and doesn't have to do
them over an over again. However, initially and in the case of actual
writing the shared resource, we want a full verification.
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 °
--
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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