Re: [TLS] Protocol Action: 'IANA Registry Updates for Transport Layer Security (TLS) and Datagram Transport Layer Security (DTLS)' to Proposed Standard (draft-ietf-tls-iana-registry-updates-05.txt)

[Peter Gutmann <[e-mail]>]

The IESG <[e-mail]> writes:

>The IESG has approved the following document:
>- 'IANA Registry Updates for Transport Layer Security (TLS) and Datagram
>   Transport Layer Security (DTLS)'
>  (draft-ietf-tls-iana-registry-updates-05.txt) as Proposed Standard

Now that it's been published, I'd like to request assignment of an extension
ID for tls_lts under the Specification Required terms.

In terms of the conflict between the existing use of 26 = tls_lts and the new
26 = compress_certificate, this can probably be managed by noting that
compress_certificate will only be sent by TLS 1.3 implementations and tls_lts
will only be sent by TLS 1.0-1.2 implementations.  In addition
compress_certificate has a nonzero size (a list of algorithms is sent) while
tls_lts has a zero size (it's an indicator flag).  This means that the two
different uses are unlikely to occur in the same implementation, and even if
they do can be distinguished by looking at the extension data size.

Having compress_certificate moved to 27 would be a better solution in terms of
existing use, but I can add a note to the LTS draft mentioning the change. The
certificate compression draft should probably also be updated to indicate that
a zero-size compress_certificate, if encountered, isn't a compress_certificate
but a tls_lts.

Peter.