On Tue, 17 Aug 2010, Matt wrote:

quoted text
> Quite possibly more of a 'which software' question:
> I am looking for a way to have two parties share documents securely through 
> an OpenBSD server.
> User A can not look into directory B but is allowed in dir C, that sort of 
> thing. Sharing occurs through untrusted / changing networks.
>
> Obviously a simple SFTP structure seems to cut it,

SFTP with chroot and using keys is by far the easiest way to achieve 
that.

quoted text
> but would require all users (different platforms) to install sftp 
> clients.

I hope that is a misunderstanding.

Text-based clients are provided by default in all distros likely to be 
used on the desktop, with the exception of one...

Also, a growing number of file managers (such as Konqueror) already 
included SFTP support and all that is necessary is to punch in a URL.

If you mean extra, graphical SFTP clients, there are many others to choose 
from besides the file managers.  Filezilla is popular in some 
demographics, same for CyberDuck and Fugu.

Others have mentiond WebDAV, which is useful but harder to set up and 
maintain accounts.  Same for Samba, which is in ports.

OpenAFS/Arla is yet another option, but is overkill for small, 
centralized groups.

/Lars