[comp.sys.sgi] 4sight .cutbuffer

jit@SLIC.CELLBIO.DUKE.EDU (Jit Keong Tan) (03/13/91)

Could the future relese of window manager (whatever it is going to be)
fix the side effect that the current copy buffer is store in a file that is
accessible by all other people:

-rw-rw-rw-   1 root		(the buffer file)

Thanks.

--------------------------------------------------------
Jit Keong Tan     | internet: jit@slic.cellbio.duke.edu
(919) 684-8098    | bitnet  : tan00001@dukemc.bitnet
--------------------------------------------------------
U.S. Mail:
Duke University Medical Center
Department Of Cell Biology
Box 3709
Nanaline Duke Bldg, Rm. 385
Durham, NC 27710

jit@SLIC.CELLBIO.DUKE.EDU (Jit Keong Tan) (03/13/91)

Ignore what I just said. It seems that the file is deleted once
the user has logged out.

Sorry.

--------------------------------------------------------
Jit Keong Tan     | internet: jit@slic.cellbio.duke.edu
(919) 684-8098    | bitnet  : tan00001@dukemc.bitnet
--------------------------------------------------------
U.S. Mail:
Duke University Medical Center
Department Of Cell Biology
Box 3709
Nanaline Duke Bldg, Rm. 385
Durham, NC 27710

blbates@AERO36.LARC.NASA.GOV (Brent Bates ViGYAN AAD/TAB) (03/14/91)

   Is the cutbuffer normally deleted?!  I checked my system default files
for NeWS and it is suppose to be deleted when you LOGIN.  This is in init.ps
And it seems to me that from experience it didn't seem to work.  I modified
my personal copy of ~/NeWS/init.ps so that when I LOGOUT, .cutbuffer is
removed.  We are running 3.3.1 and 3.3.0, so I don't know if this bug was
fixed in 3.3.2.  Also this maybe a mute point when 4.0 comes out.  Will this
type of thing be totally different?  Will there be a /tmp/.cutbuffer?

	Brent L. Bates
	NASA-Langley Research Center
	M.S. 361
	Hampton, Virginia  23665-5225
	(804) 864-2854
	E-mail: blbates@aero36.larc.nasa.gov or blbates@aero8.larc.nasa.gov

rpw3@rigden.wpd.sgi.com (Rob Warnock) (03/14/91)

In article <9103131541.AA21424@slic.cellbio.duke.edu>
jit@SLIC.CELLBIO.DUKE.EDU (Jit Keong Tan) writes:
+---------------
| Could the future relese of window manager (whatever it is going to be)
| fix the side effect that the current copy buffer is store in a file that is
| accessible by all other people:
| 
| -rw-rw-rw-   1 root		(the buffer file)
+---------------

Well, the answer is "yes" and also "no". You see, in the X environment there
is no cutbuffer "file" -- the cutbuffer(s) and primary selection buffer are
in memory inside the X server, so no one can read them as a file. Also, since
the X server gets reset when you log out, the cut/selection buffer(s) don't
survive across logins.

That was the good news...

However, *any* user at *any* host that you permit access to your X server
with the "xhost" command can read and write *anything* in your X server,
including your selection/cut buffer(s). And that includes any user running
on *your* workstation, not just "root". For example, a friend of mine has
no password on the "guest" login on his workstation. So...

	% rcp xselection guest@his_machine:/usr/tmp
	% rsh his_machine -l guest /usr/tmp/xselection -display :0 PRIMARY
    /   Erase is control-H
   /    Kill is control-U
+-{     42 cd /usr/lib/X11/xdm
|  \    /usr/lib/X11/xdm
|   \   43 ls -l
|    \  total 13
|
+- This is what happens to be in his primary selection buffer.

("xselection" is a publicly-available program, but note that any skilled X
programmer could write something like it.)

That was the bad news...

The really long answer I'll forego here (since I don't even know all the
details myself!), but suffice it to say that there are other forms of
authentication that can be used besides the simple "xhost", but that's
the default.

At least the buffers disappear at logout, which is an improvement...


-Rob

-----
Rob Warnock, MS-1L/515		rpw3@sgi.com		rpw3@pei.com
Silicon Graphics, Inc.		(415)335-1673		Protocol Engines, Inc.
2011 N. Shoreline Blvd.
Mountain View, CA  94039-7311