From: "Robert A. Rosenberg" <hal9001@panix.com>
Date: Thu, 31 Aug 95 21:58:44 PDT
To: Piete Brooks <Piete.Brooks@cl.cam.ac.uk>
Subject: Re: SSL search attack
Message-ID: <v02130508ac6c2efca958@[166.84.254.3]>
MIME-Version: 1.0
Content-Type: text/plain


At 07:33 8/31/95, Piete Brooks wrote:
> I am against pre-fetching of the next chunk, as I believe it should not be
>        necessary (I'll review that after Hal3) and it tends to increase NOACKs

I see nothing wrong with the concept of being allocated an initial chunk
and having the scan software attempt to ACK it when 50% of it has been
searched. A successful ACK would allow the releasing of a new chunk (in
response) equal in size to the returned chunk. A failure of the Server to
accept the ACK would trigger a retry at set intervals (such as 75% and 100%
or 60/70/80/90/100%) until the Server responds. Thus the scanner is always
in possession of a Full Sized Chuck to scan (so long as the Server accepts
an ACK before the 100% done mark) and temporary failures will not stop the
process of a scanner as currently happens.

Note: All this does is alter the size of the initial chunk granted and
allow the scanner to report partial progress and reset the scanned range
back to the original chunk size (ie: The Scanner never has more than the
designated assigned chunk size at any time - it just gets refreshed in
pieces [thus allowing overlap of scanning with getting a new range to scan]
in lieu of all at once [which has a failure to accept the ACK as a bottle
neck in uninterrupted scanning]).