Subject: [dhcwg] Roman Danyliw's No Objection on draft-ietf-dhc-dhcpv6-yang-24: (with COMMENT)

From: Roman Danyliw via Datatracker <[email-masked]>
Date: Tue, 14 Dec 2021 15:06:24 -0800

Roman Danyliw has entered the following ballot position for
draft-ietf-dhc-dhcpv6-yang-24: No Objection

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COMMENT:
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Thank you to Vincent Roca for the SECDIR review.

** (Editorial) Regex constraining hex strings.  When I first read the pattern
constraining typedef duid-base (and the same is true in other places), I didn’t
appreciate that this regex was operating on a string containing a hex
representation of octets.

** There are a few places in the three yang modules where it appears that
human-readable messages are being returned.  What is the expected approach (if
any) for conveying a language tag per the guidance in Section 4.2 of BCP18?  An
incomplete list of these places are:

-- Section 4.1. grouping status and status-code-option-group has a leaf message

-- Section 4.2. rpc delete-address-lease and delete-prefix-lease return a leaf
return-message

-- Section 4.3. leaf return-message in the rpcs

** Section 4.1. grouping status has a leaf message which is explicitly
described as of “type string” and is clarified as being a “UTF-8 encoded string
... that isn’t null-terminated”.  No issues with that guidance.  I’m wonder
whether the other strings mentioned in the previous comment should also be
described in this way.

** Section 5.  Additionally threats to document would be:

-- Generalize the threat of redirecting clients to services under the
attackers’ control (e.g., DNS server or WPAP).  Say:

OLD
* Various attacks based on re-configuring the contents of DHCPv6
      options, leading to several types of security or privacy threats.
      For example, changing the address of a DNS server supplied in a
      DHCP option to point to a rogue server.

NEW
* Various attacks based on re-configuring the contents of DHCPv6 options,
leading to several types of security or privacy threats.  These options could
redirect clients to services under an attacker’s control. For example, changing
the address of a DNS server supplied in a DHCP option to point to a rogue
server.

-- Ability to read the leases from the Server or Relay could help the attacker
fingerprint device types.

OLD
These subtrees and
   data nodes can be misused to track the activity of a host:

NEW
These subtrees and data nodes can be misused to track the activity or
fingerprint the device type of the host: