Re: [TLS] draft-rescorla-tls-renegotiate.txt

Michael D'Errico <mike-list@pobox.com> Fri, 06 November 2009 19:53 UTC

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Date: Fri, 06 Nov 2009 11:55:06 -0800
From: Michael D'Errico <mike-list@pobox.com>
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Subject: Re: [TLS] draft-rescorla-tls-renegotiate.txt
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> I assume that this WG, the IETF, the vendors and the consumers would
> appreciate if the fix could be applied to the entire installed base,
> no matter what protocol level each component implements.
> 
> It's not always an option to move to a newer implementation that
> also supports a more recent version of TLS, so I would appreciate
> that we describe two additional things in this draft:
> 
>    - to describe how to add/implement this fix to each and
>      every affected protocol version of the SSL/TLS Family.
> 
>      I just noticed that SSLv3 does _NOT_ have a "no_renegotiate" alert!
>      To me, it looks like the SSLv3 spec does not specify how to
>      deny performing a renegotiate.  Which is slightly odd, since
>      there are SSLv3 implementations that do not implement renegotiation...

Even more importantly, SSLv3 does not support extensions.

Mike


>    - to describe/suggest the behaviour for implementations of SSL/TLS
>      that do not support (or do not want to perform) renegotiation,
>      in particular for SSLv3.
> 
>    - since we currently overload the empty extension with signaling
>      to different things: 
>        - I am a patched server
>        - I support secure renegotiation
> 
>      we should probably explicitly describe what a TLS v1.x Server
>      should do if it does not implement TLS renego in the server or
>      reliably know that it will not perform renegotiation.
>      Since it is against common sense that such a server responds
>      with a TLS Extension "I support secure renegotiation" in
>      the ServerHello, we should explicity write what we want them
>      to implement.
> 
> 
> -Martin