[secdir] SECDIR review of draft-ietf-mmusic-sdp-mux-attributes-13

[Chris Lonvick <[e-mail]>]

Hi,

I have reviewed this document as part of the security directorate's 
ongoing effort to review all IETF documents being processed by the IESG. 
These comments were written primarily for the benefit of the security 
area directors. Document editors and WG chairs should treat these 
comments just like any other last call comments.

I've been rather busy and haven't had time to thoroughly review this 
document. But I did look at the Security Considerations section and will 
recommend that some additions be made. The Security Considerations 
section says, "This document does not add any new security 
considerations beyond the existing considerations in the RFCs for 
protocols that are being multiplexed together. " (First paragraph.) I 
believe that it would be helpful to readers and implementers if the 
specification were to give pointers to RFCs for protocols that are being 
multiplexed together, and their security considerations.

The section continues by saying, "The ways that SRTP streams are keyed 
is not believed to create any two-time pad vulnerability for the 
currently defined SRTP keying mechanism." (Second paragraph.) I may not 
have seen it but I don't believe that this document specifies keying for 
SRTP streams, but only references RFC4567 (Section 5.35) and RFC4572 
(Section 5.36). If that's the case, then this document doesn't need to 
opine about possible vulnerabilities in that area; leave it to those or 
subsequent documents to make that analysis.

It would be appropriate to reiterate that the CAUTION category may 
produce some problems.

For completeness, it may be good to include pointers to other mmusic and 
SDP documents that have addressed security aspects. A statement of how 
that may apply to this specification would be appropriate. I don't think 
this would need to be detailed.

Best regards,
Chris