Updates to RFC 4572
Ericsson
Hirsalantie 11
Jorvas
02420
Finland
christer.holmberg@ericsson.com
RAI
This document updates RFC 4572 by clarifying the usage of multiple SDP 'fingerprint'
attributes with a single TLS connection. The document also updates the preferred
cipher suite to be used, and removes the requirement to use the same hash function
for calculating the certificate fingerprint that is used to calculate the
certificate signature.
RFC 4572 specifies
how to establish Transport Layer Security (TLS) connections using
the Session Description Protocol (SDP) .
RFC 4572 defines the SDP 'fingerprint' attribute, which is used to carry a secure hash
value associated with a certificate. However, RFC 4572 is currently unclear on whether
multiple 'fingerprint' can be associated with a single SDP media description ("m= line")
, and the associated semantics.
Multiple 'fingerprint' attributes are needed when an endpoint wants to provide multiple
fingerprint, using different hash functions, for a certificate. Multiple 'fingerprint'
attributes are also needed if an endpoint wants to provide fingerprints associated with
multiple certificates. For example, with RTP-based media, an endpoint might use different
certificates for RTP and RTCP.
RFC 4572 also specifies a preferred cipher suite. However, the currently preferred
cipher suite is considered outdated, and the preference needs to be updated.
RFC 4572 mandates that the hash function used to calculate the fingerprint is the same
hash function used to calculate the certificate signature. That requirement might
prevent usage of newer, stronger and more collision-safe hash functions for calculating
certificate fingerprints.
This document updates RFC 4572
by clarifying the usage of multiple SDP 'fingerprint' attributes with a single
TLS connection. The document also updates the preferred cipher suite to be used, and
removes the requirement to use the same hash function for calculating the certificate
fingerprint and certificate signature.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in .
This section updates section 5 of RFC 4572.
This document improves security.
This document makes no requests from IANA.
Martin Thompson, Paul Kyzivat and Jonathan Lennox provided valuable comments and input on this document.
[RFC EDITOR NOTE: Please remove this section when publishing]
Changes from draft-holmberg-mmusic-4572-update-01
Adopted WG document (draft-ietf-mmusic-4572-update-00) submitted.
IANA considerations section added.