Re: [dane] Extending TLSA RFC to operate with TLS's new raw public keys

[Viktor Dukhovni <[e-mail]>]

On Thu, May 29, 2014 at 01:05:17AM -0700, John Gilmore wrote:

> In reviewing the draft, I noticed that it doesn't ever describe how
> you store such a public key in a TLSA record.

I think there is an obvious format, that should be spelled out
explicitly in some suitable document.  Namely the same format as
for the SPKI of a leaf certificate with any supported matching
type:

    ; Match SPKI of a certificate or just the bare public key
    _25._tcp.mx1.example.com IN TLSA DANE-EE(3) SPKI(1) ? {blob}

DANE TLS clients that also support the new TLS oob public key
extension can include it in their client HELLO, provided every RR
in the TLSA RRset is a "3 1 X" RR (they must perform the DNS lookup
before client HELLO).  If any of the RRs have a different usage,
then a full leaf certificate may be required, and the client MUST
NOT signal oob public key support (since the client would potentially
be unable to match a subset of the TLSA records, which may the
currently active configuration).

-- 
	Viktor.