Subject: [rtcweb] Requirements for SRTP profile?

From: Taylor Brandstetter <[email-masked]>
Date: Fri, 14 Apr 2017 08:46:33 -0700

Chrome has been offering the "SRTP_AES128_CM_HMAC_SHA1_32" profile for some
time (in the interest of saving a few bytes per packet), and I'm trying to
figure out if this is acceptable or not.

security-arch
<https://tools.ietf.org/html/draft-ietf-rtcweb-security-arch-12> says the
following:

   - "implementations MUST NOT negotiate cipher suites with NULL encryption
   modes"
   - "The DTLS-SRTP protection profile SRTP_AES128_CM_HMAC_SHA1_80 MUST be
   supported for SRTP"

Unless I'm overlooking something, this seems to indicate that offering
"SRTP_AES128_CM_HMAC_SHA1_32" *is* acceptable, as long as
"SRTP_AES128_CM_HMAC_SHA1_80" is offered as well. Is my interpretation
correct?

---

From: Peter Thatcher <[email-masked]>
Date: Fri, 14 Apr 2017 17:02:32 +0000

Yes, I believe that is correct.

On Fri, Apr 14, 2017 at 8:46 AM Taylor Brandstetter <[email-masked]>
wrote:

> Chrome has been offering the "SRTP_AES128_CM_HMAC_SHA1_32" profile for
> some time (in the interest of saving a few bytes per packet), and I'm
> trying to figure out if this is acceptable or not.
>
> security-arch
>    - "implementations MUST NOT negotiate cipher suites with NULL
>    encryption modes"
>    - "The DTLS-SRTP protection profile SRTP_AES128_CM_HMAC_SHA1_80 MUST
>    be supported for SRTP"
>
> _______________________________________________
> rtcweb mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/rtcweb
>