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Re: replay field size
At 04:44 PM 2/8/97 -0800, Derrell Piper wrote:
>There was clear consensus at the ANX IPSEC bakeoff last week to make the
>size of the replay field 32-bits for both AH and ESP. If we _must_ have
>alignment for IPv4 IPSEC then the additional bits should be specified as
>alignment. No one wants to do 64-bit math for replay computation. It's
>silly. In my opinion, IPv4 is misaligned for 64-bit hardware anyway and I
>don't see the point of aligning the fields just to keep the protocol
>consistent with IPv6.
IPv6 headers need to be 8-byte aligned. Thus AH header must be a multiple
of 8-bytes in length. For IPv4, a multiple of 4-bytes is fine. The AH
data doesn't have to be 8-byte aligned. [The destination option header
comes after the AH and can contain options that require 8-byte alignment].
>I don't think this issue needs the Security AD to resolve. I think we
>already have consensus. Let's hear now from anyone who absolutely must
>have 64 bits or else move to revise AH and ESP to reflect consensus. We
>have much more interesting things to argue about.
All I want is that the AH header in IPv6 packets to be a multiple of 8-bytes
in length. A 32-bit replay field is fine. I don't even care where the
padding is (it would be nice if it were in a standard place), just that
it exists.
Matt Thomas Internet: matt@lkg.dec.com
UNIX Networking WWW URL: http://ftp.digital.com/%7Ethomas/
Digital Equipment Corporation Disclaimer: This message reflects my own
Littleton, MA warped views, etc.