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Re: STARTTLS & EHLO

2009-01-28 11:59:42

Tony Finch wrote:
As far as I can see it is clear. "The server MUST discard any knowledge
obtained from the client [...] which was not obtained from the TLS
negotiation itself. The client MUST discard any knowledge obtained from
the server [...] which was not obtained from the TLS negotiation itself."

The parts which I have elided are just examples, because they start "such
as".
  
It can't be that clear, because myself, Tony Hansen and John Klensin all
saw the other interpretation...

To me, it was (initially) 'clear' that the example saying 'such as the
argument to the EHLO command', was precise enough to imply that the fact
that the EHLO command was sent should not be discarded. It could have
said 'such as the EHLO command', but it went out of its way to say '*the
argument to* the EHLO command'.

To me, the rest of the text seems to be clarifying that the client
should send another EHLO command if it wants to use any extensions,
because the list of extensions may have changed, but if it doesn't want
any extensions, it doesn't matter if it doesn't send another EHLO,
although it's recommended that it does. (ie SHOULD not MUST).

So, I don't think it was clear. I'm not really that fussed which way it
means, I just thought it might need clearing up (one way or the other)
in the next iteration of the document, or an info note on it.

-- 
Paul Smith

VPOP3 - POP3/SMTP/IMAP4/Webmail Email server for Windows

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