On Sun, 24 Jan 2021 at 23:03, <internet-dra...@ietf.org> wrote: > A New Internet-Draft is available from the on-line Internet-Drafts > directories. > This draft is a work item of the Transport Layer Security WG of the IETF. > > Title : Delegated Credentials for TLS
I'm a little confused too by the meaning of 4.1.3: # 1. Validate that DelegatedCredential.cred.valid_time is no more than # 7 days. I read this as saying that a certificate can only be usable for delegation in the first 7 days after it's notBefore. That follows from valid_time being an offset in seconds from notBefore, and validation step 3 covers the "maximum validity period" mentioned elsewhere in the draft. This sounds a bit odd. Honestly, I find the name and definition of valid_time a little unclear. It's neither a "validity time" instant, or a period. Perhaps "validity_offset"? But it may be simpler to just make it 64 bits and _make_ it a UTC instant -- with the added benefit that this may result in fewer implementations doing unsigned 32-bit arithmetic on times in seconds and breaking ~15 years hence. I think this draft would also benefit from explicitly drawing out (d) in this thought process: a) for performance reasons[1], it seems unlikely that RSA keys are workable as delegated credentials. b) a huge amount of the webpki is still built on RSA. c) given (a) and (b), a common deployment strategy will mean mixed authentication cryptography in handshake authentication: RSA for the webpki portion, ECDSA/EdDSA perhaps for delegation. d) and this is OK (as it is in webpki), and totally allowed, and expected. Thanks, Joe [1] expensive, non-deterministic key generation; large key sizes _______________________________________________ TLS mailing list TLS@ietf.org https://www.ietf.org/mailman/listinfo/tls
