Path: utzoo!yunexus!ists!jarvis.csri.toronto.edu!mailrus!ames!think!samsung!cs.utexas.edu!tut.cis.ohio-state.edu!ucbvax!ulysses!smb From: smb@ulysses.homer.nj.att.com (Steven M. Bellovin) Newsgroups: comp.org.usenix Subject: Re: USENIX Board Studies UUCP Message-ID: <12401@ulysses.homer.nj.att.com> Date: 18 Nov 89 22:30:43 GMT Article-I.D.: ulysses.12401 References: <287@usenix.UUCP> <1624@crdos1.crd.ge.COM> <49017@looking.on.ca> Organization: AT&T Bell Laboratories, Murray Hill Lines: 20 There have been several attempts to write uucp replacements or look-alikes over the years. Many of them fail on the issue of assurance: how do we know this will work in the real world? The better versions of uucp (HDB, and I think 4.3bsd's) are the product of many years of learning to deal with improbable or impossible conditions (to say nothing of the bug fixes they have). The odds are high that you'll end up with new bugs, unless someone *very* experienced and *very* gifted write it. Even that's no guarantee. HDB uucp was supposed to be much more secure than its predecessor. It was, but not by much at first -- mostly because it let the shell get too close to user-supplied data. But the creation of uusched provided powerful isolation from ``poison pill'' files that would kill off uucico. One site might be affected, but communication with others would survive. A few years ago, I had the opportunity to evaluate a uucp replacement. It was far cleaner, and inherently far more secure. I rejected it, though, for the reasons I cite above: the programmer was insufficiently paranoid. I'd seen too many wedged links caused by ``impossible'' conditions, and this program made no attempt to detect or recover from such errors. A pity; it had promise.