Re: tlug: Fine control over ftp

[Scott Stone <sstone@example.com>]

On Wed, 30 Sep 1998, Stephen J. Turnbull wrote:

> >>>>> "Chris" == Chris Sekiya <chris@example.com> writes:
> 
>     Chris> On Wed, 30 Sep 1998, Darren Cook wrote:
>     >> That worked! Why does ftp require a shell to exist, when
>     >> obviously it is not using it?
> 
>     Chris> There was probably a good reason for it, but I've
>     Chris> forgotten.  Stephen?
> 
> As a guess...
> 
> To implement `mget *.tar.gz'?  Or `quote site ...'?  I'm fresh
> out of suggestions that would be easier to code than using system().
> ;-)  (For innocent bystanders, system() does invoke a shell, unlike
> exec().)
> 
> Scott Perlman's suggestion of security may be more authoritative,
> although I think it's unlikely since I believe that ftpd uses neither
> login(1) nor code stolen en bloc from login(1) to authenticate users.

TL's (and I think Redhat's too) uses pam to authenticate users.  I think
that's a compile-time option for wu-ftpd.

> 
> Putting /bin/false in /etc/shells is just a little too tricky for my
> taste for distinguishing between authorized ftp users and authorized
> telnet users, and would not allow you to authorize telnet but not ftp
> (eg for MUD connections).

Probably not a good example - muds usually run on non-standard ports such
as 3000, and shell access is irrelevant, as muds don't usually use the
system password files.

--------------------------------------------------
Scott M. Stone <sstone@example.com, sstone@example.com>
               <sstone@example.com>
Head of TurboLinux Development/Systems Administrator
Pacific HiTech, Inc (USA) / Pacific HiTech, KK (Japan)
http://www.pht.com		http://armadillo.pht.co.jp
http://www.pht.co.jp	        http://www.turbolinux.com


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