Subject: [Netconf] Fwd: Secdir review of draft-ietf-netconf-restconf-09

From: Benoit Claise <[email-masked]>
Date: Tue, 12 Jan 2016 11:08:55 +0100

FYI. The early security directorate review

Regards, Benoit

-------- Forwarded Message --------
Subject: 	Secdir review of draft-ietf-netconf-restconf-09
Date: 	Tue, 12 Jan 2016 08:27:53 +0000
From: 	Xialiang (Frank) <[email-masked]>
To: 	[email-masked] 
<[email-masked]>
CC: 	Tobias Gondrom <[email-masked]>, [email-masked] 
<[email-masked]>, [email-masked] <[email-masked]>

Hello,

I have reviewed this document as part of the security directorate's 
ongoing effort to review all IETF documents being processed by the 
IESG.  These comments were written primarily for the benefit of the 
security area directors.  Document editors and WG chairs should treat 
these comments just like any other last call comments.

This document describes an HTTP-based protocol that provides a 
programmatic interface for accessing data defined in YANG, using the 
datastores defined in NETCONF.

The document appears in reasonably good shape.

In general, the RESTCONF is an application protocol layered on the HTTP 
protocol. As mentioned in the document, just using the HTTPS (with TLS) 
can address most of the security issues such as confidentiality, 
integrity, etc. In other words, RESTCONF is designed inherently based on 
a good security foundation.

But there are still several security issues (TBDs) missing in the 
document that need to be addressed before publication.

Below is a series of my comments, questions for your consideration.

Discussion: Section 2

Since this section is all about the security requirements to the 
RESTCONF transport protocol, is it appropriate to combine it into the 
security consideration section directly?

Questions:

Section 4.3

What is the error handling if GET method is used to retrieve the 
operational resources?

Section 4.5

What is the error handing if PUT method does not include the message body?

Generally, the similar problems like the above two appear several times 
in the document, please double check them.

Comments: Section 12

In the security considerations section, there are still some serious 
security issues not mentioned:

1. DDoS attack: One RESTCONF client is possible to communicate with a 
lot of RESTCONF servers, which potentially leads to the situation of 
DDoS attack to itself or its link. How to avoid or mitigate it?

2. Replay attack: the attacker records a sequence of messages off the 
wire and plays them back to the RESTCONF server/client. To protect 
against it, the common methods include using timestamp or sequence id.

Questions: Section 12

1. "Security considerations for the content manipulated by RESTCONF can 
be found in the documents defining data models.": which documents are 
mentioned in this sentence for defining data models?

2. nits: "Implementors SHOULD provide a comprehensive authorization 
scheme with...". Here, should "authorization" be "authentication"?

Thank you.

B.R.

Frank