RFC 5764, "Datagram Transport Layer Security (DTLS) Extension to Establish Keys for the Secure Real-time Transport Protocol (SRTP)", May 2010Source of RFC: avt (rai)
Errata ID: 4788
Reported By: Eric Rescorla
Date Reported: 2016-08-30
Verifier Name: Ben Campbell
Date Verified: 2016-11-08
Section 4.2 says:
which are assigned as shown below. The per-association context value is empty.
It should say:
which are assigned as shown below. No per-association context value is used.
This code is somewhat ambiguous, though the better interpretation is probably that you should use a zero-length context (arm 2 of https://tools.ietf.org/html/rfc5705#section-4). However, real implementations do not seem to use the exporter value, so we need to resolve this in that direction.