Path: utzoo!mnetor!geac!gjetor!adeboer From: adeboer@gjetor.geac.COM (Anthony DeBoer) Newsgroups: news.software.b Subject: Re: Cnews and the cancel control command Message-ID: <1991Feb6.221123.23610@gjetor.geac.COM> Date: 6 Feb 91 22:11:23 GMT References: <1991Feb4.002104.12830@wolves.uucp> <1991Feb4.185130.6956@zoo.toronto.edu> Organization: Geac J&E Systems Ltd. Lines: 28 In article <1991Feb4.185130.6956@zoo.toronto.edu> henry@zoo.toronto.edu (Henry Spencer) writes: >In article <1991Feb4.002104.12830@wolves.uucp> ggw%wolves@cs.duke.edu (Gregory G. Woodbury) writes: >>Has anyone else felt the desire to have the cancel command be a bit more >>controlled in Cnews? ... > >The desire, yes... but the flesh is weak. :-) The problem is that forging >news articles (including control messages) is trivial, and there is no >simple check that cannot be bypassed easily by the determined canceller. >-- >"Maybe we should tell the truth?" | Henry Spencer at U of Toronto Zoology >"Surely we aren't that desperate yet." | henry@zoo.toronto.edu utzoo!henry Maybe I'm all wet, but what about using the Paths: header? Ignore the cancel message if the path of the cancel doesn't match the path of the original article. The one main problem I see is that with redundant newsfeeds, the original and the cancel might have propagated from the poster's machine to my box down different paths and a legitimate cancel could be rejected. The other is that a determined forger on any of the machines involved, or at a neighbour of any of these machines except the poster's, could forge the appropriate Path: line. That would at least cut way down on the number of sites that could forge a cancel. At least leaf sites of minor sites would be SOL. (Or does the Internet make everybody each other's neighbour? I'm out in UUCP-land here.) Are there any other problems with the idea, or are these two problems sufficient to make it Not Worth Doing? -- Anthony DeBoer - NAUI #Z8800 adeboer@gjetor.geac.com Programmer, Geac J&E Systems Ltd. uunet!geac!gjetor!adeboer Toronto, Ontario, Canada #include