eap Mailing List: Re: Issue 218: TLS example

[Bernard Aboba (aboba]

> It worries me that the RFC may not be clear on this. If its not,
> there can be implementations that do it in another manner than
> you assume. I agree it would make sense to do it as you explain,
> but maybe the implementor has read Section 3.8... Anyway, this
> is not a 2284bis issue. But we should keep that in mind for a
> possible future update of the EAP-TLS RFC or in discussions
> of what protection exists in EAP.

I've checked the TLS RFC, and there is no problem with ending a TLS alert
at any point after data transmission has commenced.  So the example in RFC
2716 is ok.  An alert can be sent before or after the server FINISHED
message, and could even be sent by the client in response to the server
FINISHED message (as opposed to the null packet illustrated).  SSL/TLS
APIs typically enable alerts to be sent at any time, too.