Subject: Re: Downloading from incoming

From: Markus Wischerath <[email-masked]>
Date: Mon, 20 Feb 1995 17:01:28 +0100

> From: [email-masked] (Dave Williss)
> 
> Is there a way I can configure wu-ftpd such that anonymous users can
> upload to the incoming directory but not download from it?  I don't
> care if they can poke around and get dir listings, but I want "get"
> to fail if they're in the incoming directory.

No problem. Simply set the upload umask, owner and group properly in
ftpaccess. The corresponding line from our ftpaccess looks like this:

upload /home2/ftp /incoming yes root ftpusers 0640 nodirs

Note that in our setup anonymous ftp has GID ftp, *not* ftpusers.

Cheers, -mw

Markus Wischerath     [email-masked]     +49 221-470-4170  
System Administrator                         Fax +49 221-470-5193
Linguistic Data Processing         University of Cologne, Germany

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From: [email-masked] (Harald Milz)
Date: Mon, 20 Feb 1995 20:33:02 +0100 (MET)

Subject: Re: Downloading from incoming
To: [email-masked]
Organization: Harry's Box

> to fail if they're in the incoming directory.

No problem if your incoming is rwxr-x-wx, for example. In this case, 
people _can_ download everything from incoming but only if they know
the exact file names. They cannot list the directory, however, nor can
they mget its contents. 

hm

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From: Sheryl Coppenger <[email-masked]>
Date: Tue, 28 Feb 1995 14:49:45 -0500 (EST)

> the exact file names. They cannot list the directory, however, nor can

It's been a while since this went through, but I didn't see a followup
that mentioned this point.

Yes, rwxr-x-wx can keep people from reading the directory but that's not 
always sufficient to keep the directory from being abused.  I know of at 
least one case where a directory set up like that was used for trading 
pirated software.  Apparently the miscreants sent their buddies email 
with the paths or posted them on bulletin boards.

We have the incoming directory set up so that anything placed there
is permission 600 owned by root.  Even the person who places it there
can't read it.  If it's something legitimate that we've been warned
about ahead of time we move it to the public area and change permissions.
Otherwise we delete everthing out of the directory periodically (even
though we warn people that they won't be able to access what they put
down they try it occasionally).

For more frequent private transfers we have a rwx--x--x directory with
subdirectory names known only to the people who will be exchanging 
information (they're not obvious).  The subdirectories are writeable.
That seems to have worked for us so far.

-- 

Sheryl Coppenger    SEAS Computing Facility Staff        [email-masked]
               	    The George Washington University     (202) 994-6853