Path: utzoo!utgpu!water!watmath!clyde!att!rutgers!mailrus!b-tech!zeeff From: zeeff@b-tech.UUCP (Jon Zeeff) Newsgroups: news.software.b Subject: Re: private newsgroups Message-ID: <4630@b-tech.UUCP> Date: 18 Jul 88 13:31:24 GMT References: <657@cbnews.att.com> Reply-To: zeeff@b-tech.UUCP (Jon Zeeff) Organization: Branch Technology Ann Arbor, MI Lines: 38 In article eric@snark.UUCP (Eric S. Raymond) writes: [ info about News 3.0 ] > >If you run with FASCIST on, you can control posting and reading access to >groups on a per-user basis. Netnews uses group permissions to achieve this. >All news database files (including article text) are created and maintained >owned by NEWSUSR and NEWSGROUP, with permissions u=rwx,g=rx,o-rwx (750). Thus >only programs that are suid or sgid NEWSUSR can read news database files. Only >programs that are suid NEWSUSR can write them. Readers are sgid NEWSUSR; >rnews, expire and sendbatch are suid NEWSUSR. > I hope that the group write permissions are turned off on *all* news files in case someone gets a sgid shell. >FASCIST mode has two minor disadvantages. ... >... The other is that users who want to roll their own readers (and >aren't just front-ending the ednews tool) will need to get someone with root >privileges to set their programs sgid NEWSUSR on each runtime generation. > It seems to me that just getting someone with root to sgid to NEWSUSR is the least of the problems. Every reader would have to be gone over very carefully and modified to protect it's sgid status. For many readers, this may be a big task that will never get done right. Where possible, I'd just stick with setting the perms on protected news groups to g=rx,o-rwx with the group set to some group that only privledged users are in. It's not as flexible, but we know it's secure. Maybe I'm wrong, but I think that a sgid secure version of rn would be a big job. -- Jon Zeeff Branch Technology, uunet!umix!b-tech!zeeff zeeff%b-tech.uucp@umix.cc.umich.edu