From: vnend@phoenix.Princeton.EDU (D. W. James)
Subject: Re: Sendsys police
Originator: news@ernie.Princeton.EDU
Organization: Princeton University
Date: Tue, 7 Apr 1992 19:48:30 GMT

In article <FFgqiB1w164w@Bogus.COM> david@Bogus.COM (David Grant) writes:
)dan@cubmol.bio.columbia.edu (Daniel Zabetakis) writes:
)>     My idea is to form a Sendsys Police force. This would be a group
)> of experienced news people who would take responsability to watch for
)> sendsys bombs, and to forge cancels for them. Not only this, bu they 
)> would also send e-mail to the other SP's, who would issue cancels from
)> thier sites. This way, there would be a good chance of stopping the
)> distribution of the control message.
 
)You have a good idea there.
 
)You could write a program that would automatically cancel the messages!
 
)Someone could be resposible for "allowing" a sendsys.  The person that
)desired a sendsys would mail to an address like sendsys@the.sendsys.police
)and would ask for a sendsys not to be canceled.
 
)The program would mail them back at their address, and ask for confirmation.
 
)Then the person could issue his sendsys without getting it canceled.
 
)That will solve the problem EASY!
)->David Grant  (David@Bogus.COM) via CyberSpace Cafe (501) 525-1681 14.4k DS

Set up a robot mailer on uunet.

Have backbone sites* running code that automatically cancels sendsys messages
if they are not in a temp. acceptable file.  Entries to this file are made
by mail from UUNET.  Sendsys messages not in the file are cancelled and the
message sent to the robot on uunet.  Have the file listing sites accepting
sendsys messages cleaned of addresses more than, say, 14 days old.

[*	Define a backbone site as the 50-250 sites in the Flow report, or
all sites over 1 that are willing to participate, or sites with conscientious
news admins...]

When a sendsys is either recieved by uunet or one is refered to it from one
of the other backbone sites, it sends a query off to the address that would
be getting bombed asking if they *really* want a sendsys, with internal
instructions that the reply should go to sendsys@uunet.uu.net with a body
of FOO of they really want a sendsys, a body of BAR to block them, and that
no response means continue to cancel sendsys's to this address.  (The BAR
response is to block someone forging a sendsys, waiting 24 hours, then forging
mail to sendsys saying FOO.)



So the pattern would run:

Sendsys sent (it doesn't matter if it is a forgery or not at this point.)

First backbone site recieves it.  It forges a cancel and sends mail to
the regulating point (hypothetically UUNET).

UUNET sends mail back to the 'posting' address querying intent and including
instructions to continue sendsys.  (We can get fairly complex at this point,
upto including a key that must be returned to UUNET to turn off protection
for that site/address for the duration.)

At this point things diverge depending on wether it was a forgery or not.

###If it was:
	Person recieving note from UUNET either ignores it, and any new sendsys
messages are treated as above, or they send back the string with an instruction
to cause the robot to automatically reject any sendsys requests from that
address without notification for some period of time.  End of story.

###If it was not a forgery:
	Person sends back a note with the key saying to enable response to
sendsys from this address.  UUNET sends mail to backbone sites running 
cancellers with instructions to pass sendsys messages for this address for
the standard period of time.

	Sender sends out second sendsys, which is then propogated across the 
distribution selected.




The only problems I see are:

	Writing the code: I don't think that this requires any great effort.
			I suspect that even I could do it, but if you want it
			soon you'd best find someone with more time.

	Sendsys takes more time:	I don't think that this is an 
			unacceptable price to pay to stop this problem.

	Impact on individual systems, other than UUNET, is not major.  And
	supporting USENET is what UUNET is for.

Advantages:

	Sendsys works.

	The vast majority of sites do not need to change software.

	Response is still automatic.

	Forged sendsys messages can only do very limited damage.

	Method can be extended to cover other auto-response messages
	(uuname, version, etc...)

Lets run with it.

-- 
Vnend, Lottery winner #316                 Ignorance is the mother of adventure.  
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