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Document: draft-ietf-netconf-restconf-15
Reviewer: Robert Sparks
Review Date: 28Jul2016
IETF LC End Date: 3Aug2016
IESG Telechat date: not yet scheduled
Summary:
Major issues:
* I am not finding any discussion in the Security Considerations or in
the text around what a server's options are if a client is asking it to
keep more state than it is willing or capable of holding. The possible
values of the "depth" query parameter (particularly "unbounded") points
out that a misconfigured or compromised client might start creating
arbitrarily deep trees. Should a server have the ability to say no?
* The third paragraph of 3.7 paraphrases to "SHOULD NOT delete more than
one instance unless a proprietary query parameter says it's ok". This
isn't really helpful in a specification. Proprietary things are
proprietary. The SHOULD NOT already allows proprietary things to do
something different without trainwrecking the protocol. Please just
delete the 2nd and 3rd sentence from the paragraph.
* Section 2.3 says "If X.509 certificate path validation fails and the
presented X.509 certificate does not match a locally configured
certificate fingerprint, the connection MUST be terminated as defined in
[RFC5246]." RFC5246 doesn't really talk about certificate validation,
and it certainly doesn't say "the connection MUST be terminated" when
certificates fail to validate. What are you trying to point to in
RFC5246 here? Should you be pointing somewhere else? (It's perfectly
reasonable for the document to reference RFC5246, and it does so
elsewhere without problem).
Minor issues:
* "A server MUST support XML or JSON encoding." is ambiguous. (2nd
paragraph of 5.2). Did you mean the server MUST support at least one of
XML or JSON but not necessarily both? I think you really intended that
the server support BOTH types of encoding.
* I _think_ I can infer that PUT can't be used with datastore resources.
Section 3.4 only speaks of POST and PATCH. Section 4.5 speaks about
"target data resource" and is silent about datastore resources. If I've
understood the intent, please be explicit about datastore resources in
4.5. If I've misunderstood then more clarity is needed in both 3.4 and 4.5.
* In 3.5.3.1 you restrict identifiers with "MUST NOT start with 'xml'
(or any case variant of that string). Please call out why (or point to
an existing document that explains why).
* The text in 5.3 about access control interacting with caching (added
based on my early review I think) doesn't mesh well with paragraph 3 of
section 5.5. There you tell the client to use Etag and Last-Modified,
but in 5.3 you say it won't work reliably when access permissions
change. At the very least 5.5 should point back into the paragraph in 5.3.
Nits/editorial comments:
* Introduction, 4th paragraph - please change "MAY provide" to
"provides". Section 3.6 explains the cases where there is choice in what
to provide.
* Section 2.3 paragraphs 1 and 2. There is edit-itis here left (I
suspect) from working in matching fingerprints. Consider combining and
simplifying these two paragraphs after improving the reference issue
called out above.
* Section 4 says "Access control mechanisms MUST be used to limit..."
This is not a good use of a 2119 MUST. I suggest replacing "MUST be"
with "are". The subsequent text already captures the actual normative
requirements on the server.
* Section 12 says "this protocol SHOULD be implemented carefully". That
is not a good use of a 2119 SHOULD. It is not a protocol requirement. I
suggest reformulating this into something like "There are many patterns
of attack that have been observed through operational practice with
existing management interfaces. It would be wise for implementers to
research them, and take them into account when implementing this
protocol." It would be far better to provide a pointer to where the
implementer should start this research.
* (micronit) Lots of examples are internally inconsistent wrt dates. For
instance, look at the 200 OK in section 3.3.3 - it says that back in
2012, a server returned something talking about a library versioned in 2016.