Re: Why IPsec is needed for iSCSI but might not be needed for RDDP/iWARP

On Jun 8, 2004, at 11:32 PM, [email protected] wrote:

>
>> But you have not said anything about the need
>> for Privacy (Encryption).  I thought that was also an important
>> consideration.
>
> Confidentiality (e.g., via encryption) is important for RDDP's placed 
> data.
> It is not clear to me that the RDDP headers require confidentiality,
> although we may wind up with a requirement that STags be randomly 
> generated
> in some fashion  (and an optional means of providing "authentication" 
> of the RDDP
> headers could meet this requirement).  Again, this depends in some 
> fashion
> on the buffer protection discussion outcome.

Confidentiality is a ULP issue. Any rationale for use of IPsec
is Authentication, not privacy.

I believe a fair summation would be that the RDDP Consumer must
be able to protect against unauthenticated updates of untagged
buffers it has taken delivery of.

There are two methods of doing this:

-- local interface enhancements that allow the RDDP Consumer to
    protect against *any* access to an untagged buffer that it
    taken delivery of, authenticated or not. This provides increases
    robustness in the face of client errors, or even in the face of
    clients that are deliberately attacking but are relying on the
    being relatively anonymous because some servers accept connections
    from a very wide number of potential clients running diverse
    implementations.

-- authentication the DDP packets, providing protection against
    un-authenticated updates even while the Data Sink is receiving data.

    Within the latter option there is technically a choice between
    authentication at the IP layer or authenticating the RDDP header
    itself. I do not believe there is *any* interest in the latter
    approach at this time.

I think it should also be emphasized, that which security enhancement
is specified, it is a relatively minor change (although it might be
expensive in the case of IPsec). It is *not* starting over from scratch
or anything like that.