Subject: [tsvwg] STARTTLS and RFC6083bis

From: Magnus Westerlund <[email-masked]>
Date: Mon, 19 Apr 2021 09:34:13 +0000

Hi,

In the replacement of RFC 6083 proposal we are have made changes that makes
STARTTLS non-viable. The reason is to remove the unclarity if a user message
is protected or not. With parallel streams during the establishment phase
supporting behavior requires additional functionality and API to deal with
it. There was also the very important aspect that DTLS requires SCTP-AUTH.
And SCTP-AUTH key management is using DTLS. Thus, STARTTLS can actually
leave the SCTP-AUTH unkeyed which is not good, or require another keying
solution, and another switch over issue. Thus, to simplify things we
initiate DTLS immediately and requires that for the SCTP association. So
from my perspective it appears simpler to have a process that if DTLS is to
used that one opens a new SCTP association with SCTP-AUTH and DTLS. 

The only STARTTLS defined usage we do know about is RFC 3788 (SIGTRAN) but
we don't know if that is actually deployed. 

Thus, anyone see an issue with this change?

The github issue for this topic:

https://github.com/gloinul/draft-westerlund-tsvwg-dtls-over-sctp-bis/issues/
35

Cheers

Magnus Westerlund