[ietf-nntp] draft-ietf-nntpext-tls-nntp-01.txt

[Charles Lindsey]

In <4047440D.1000208 at oceana.com> Ken Murchison <ken at oceana.com> writes:

>I believe its done this way in other protocols because SSL/TLS is mostly 
>used to protect the authentication credentials, not the actual message 
>data.  I don't think there isn't any technical reason why STARTTLS 
>couldn't be done after authentication, but since most (if not all) 
>applications are accustomed to having any SASL security layer nested 
>*inside* of a SSL/TLS layer, allowing STARTTLS after authentication 
>would break this paradigm.  This is also the same reason why most 
>protocols don't allow reauthentication via SASL (handling of multiple 
>security layers).

But switching to TLS just for the password exchange (whatever), and then
likely remaining in TLS for the rest of the session, seems a vast overkill
(except in private networks that might actually need TLS throughout).

Are there no authentication methods that allow a challenge/response such
that an eavesdropper who hears the exchange is still unable to reproduce
it? And are such methods included within the overall SASL scheme?

For example, I surrently authenticate to my mail server using CRAM-MD5 and
it does not, so far as I am aware, involve any switch into TLS. Or does
it?

-- 
Charles H. Lindsey ---------At Home, doing my own thing------------------------
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