Re: [TLS] Explicit error expectations (was Re: Deprecate SHA1 for signatures in TLS 1.3)

[Dave Garrett <[e-mail]>]

On Saturday, July 11, 2015 01:09:11 am Viktor Dukhovni wrote:
> Or are you just summarizing current state, with any proposed changes
> to be discussed separately?

Yes.

> The decision of whether the chain is or is not
> supported by the client MUST be left to the client.  The server
> does not have sufficient information to make this decision unilaterally
> (even if knows all the signature algorithms the client appears to
> support).

Just an idea, but maybe a way for the client to state that desire should be added? Maybe add "any(255)" values to the enums so clients could request, e.g. {any,rsa}+{any,ecdsa} or {any,any}, etc.? (there might be a better way to do this, though)

I'm not against the idea that the server should be required to always send a valid cert chain, even if it believes the client can't handle it. At a minimum, this could be useful for debugging as the client would be sent something for you to figure out why it's not working.


Dave