Subject: Protocol Action: TLS over SCTP to Proposed Standard

From: The IESG <[email-masked]>
Date: Thu, 31 Oct 2002 16:53:29 -0500

The IESG has approved the Internet-Draft 'TLS over SCTP'
<draft-ietf-tsvwg-tls-over-sctp-00.txt> as a Proposed Standard.  This
document is the product of the Transport Area Working Group Working
Group.  The IESG contact persons are Allison Mankin and Scott Bradner.

Technical Summary 
     
 This document describes the usage of the Transport Layer Security (TLS)
 protocol, as defined in [RFC2246], over the Stream Control Transmission
 Protocol (SCTP), as defined in [RFC2960].

 TLS is designed to run on top of a byte-stream oriented transport
 protocol providing a reliable, in-sequence delivery. Thus, TLS is
 currently mainly being used on top of the Transmission Control Protocol
 (TCP), as defined in [RFC793].

 SCTP has a number of different features from those of TCP, and this
 specification shows how TLS should be used with those features. 
 This document defines

           - how to use the multiple streams feature of SCTP.

           - how to handle the message oriented nature of SCTP.

 The document prohibits the use of SCTP's unordered message 
 delivery with TLS, since TLS requires in-sequence delivery in the
 underlying transport. SCTP has controls to prevent unordered data
 use, so this is a limitation, but it not does not complicate the
 mapping to TLS. 

 The specification describes the use of full TLS handshake on
 multiple SCTP streams in an association, full handshake on an
 initial stream, followed by abbreviated (session resumption)
 handshakes on additional streams, and use of abbreviated
 handshakes on all streams, resuming from a TLS handshake 
 established by a pre-existing association. 

 Finally, the specification shows how the host multi-homing
 feature of SCTP (the ability of the SCTP association to be
 bound to multiple interfaces on the same host, with multiple
 IP(v4/v6) addresses) interacts with TLS: TLS security 
 decisions must not be made based on IP-address, but rather on
 some other authenticated identity. Following this rule,
 a planned extension of SCTP to dynamically add or delete
 IP-addresses to the association will also be usable with TLS.

 Working Group Summary 
     
 The working group supported advancement. The document, 
 while still a non-working group internet-draft, had several 
 iterations to make the tradeoffs of choices about the use of
 full and abbreviated handshakes clear enough. The TLS Working
 Group supported development of the specification by the TSVWG,
 and no issues were raised in IETF Last Call from the TLS
 Working Group or the IETF community.
     
 Protocol Quality 
     
 The document was reviewed for the IESG by Allison Mankin.