The following errata report has been verified for RFC9000,
"QUIC: A UDP-Based Multiplexed and Secure Transport". 

--------------------------------------
You may review the report below and at:
https://www.rfc-editor.org/errata/eid7861

--------------------------------------
Status: Verified
Type: Technical

Reported by: Mike Bishop <[email protected]>
Date Reported: 2024-03-20
Verified by: Zaheduzzaman Sarker (IESG)

Section: 8.1.2

Original Text
-------------
If a server receives a client Initial that contains an invalid Retry
   token but is otherwise valid,


Corrected Text
--------------
If a server receives a client Initial that contains a token that is
   identifiable as a Retry token, but the token is invalid or does
   not otherwise validate the client's address,


Notes
-----
Valid tokens MUST be a) integrity-protected (Section 8.1.4) and distinguishable 
as to purpose (Section 8.1.1), i.e. tokens from a Retry packet vs. tokens from 
NEW_TOKEN frames. To satisfy address validation, they should enable the server 
to verify the client's transport address. This text does not specify which form 
of invalidity is being discussed -- failure of integrity protection or a 
mismatch between the contents of the token and the client's address.

Applying this text to all "invalid" tokens which appear to be Retry tokens does 
not allow for the scenario where the token was generated by another server / 
another QUIC implementation and is in fact unreadable. Such tokens, even if 
they appear to be Retry tokens, are supposed to be handled by the requirements 
in 8.1.3, i.e. ignore the token and handle the packet as if no token were 
present.

This section should be scoped only to tokens which are correctly formatted and 
readable by the server, but whose contents are not sufficient to prove the 
client's transport address is valid. Otherwise, the determination that the 
token is a Retry token cannot be trusted.

(This discrepancy appears in a multi-CDN context, where tokens generated by one 
CDN will sometimes be received by a different CDN; if these tokens appear to be 
"invalid Retry tokens", the connection is closed when the token should simply 
be ignored.)

Also see the discusion here 
(https://mailarchive.ietf.org/arch/msg/quic/-NcqDysNsU7mSXhKdCdM63MLYOc/)

--------------------------------------
RFC9000 (draft-ietf-quic-transport-34)
--------------------------------------
Title               : QUIC: A UDP-Based Multiplexed and Secure Transport
Publication Date    : May 2021
Author(s)           : J. Iyengar, Ed., M. Thomson, Ed.
Category            : PROPOSED STANDARD
Source              : QUIC
Stream              : IETF
Verifying Party     : IESG

Reply via email to