Re: [TLS] I-D Action:draft-ietf-tls-dtls-heartbeat-01.txt

Martin Rex <mrex@sap.com> Thu, 10 February 2011 13:56 UTC

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From: Martin Rex <mrex@sap.com>
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To: Michael.Tuexen@lurchi.franken.de (=?iso-8859-1?Q?Michael_T=FCxen?=)
Date: Thu, 10 Feb 2011 14:56:25 +0100 (MET)
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Subject: Re: [TLS] I-D Action:draft-ietf-tls-dtls-heartbeat-01.txt
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=?iso-8859-1?Q?Michael_T=FCxen?= wrote:
> 
> >>> 
> >>>> The intention of the sentence in the ID is that you can not send
> >>>> multiple HeartbeatRequest out.
> > 
> > Duplicates can result from other phenomena, not just deliberate
> > retransmission.
>
> What is the point here? The rule is to protect the network.
> The receiver has to handle any kind of duplication, but that
> is not the point here.


An over-simplified statement like


   There MUST NOT be more than one HeartbeatRequest message in flight at
   a time.

is inappropiate for the stated purpose.

This single statement does not differentiate between compliant behaviour
for the sender and compliant behaviour for the receiver.
If it is necessary for the _receiver_ to handle duplicates gracefully
then this _must_ be spelled out seperately.

As it is, the wording of the spec implies that the receiver of duplicated
HeartbeatRequest messages needs to abort the connection with a
fatal error in order to comply with the specification.


-Martin