Norbert Preining wrote:
Dear all!
THe packages of ConTeXt I am currently preparing are tested by a user
and he send back the following questions/comments. Could you please
comment on this.
For the background: I install all the stubs from
scripts/context/stubs/unix
into /usr/bin, add a texmfstart stub that calls ruby with the right path
to texmfstart.rb.
- Forwarded message from Mike Bird [EMAIL PROTECTED] -
From: Mike Bird [EMAIL PROTECTED]
Subject: New texexec very confused
To: [EMAIL PROTECTED]
Date: Tue, 24 Oct 2006 20:52:30 -0700
The new ruby texexec is very confused. The problem of output
defaulting to pdf instead of dvi has already been noted. Here
are some additional problems:
Command:texexec --output=dvips foo
Should produce: foo.dvi
Actually produces: foo.pdf
hm, i need to check that, maybe there is no dvips option
Command:texexec --dvi foo
Should produce: foo.dvi
Actually produces: foo.dvi AND OVERWRITES foo.ps
--Mike Bird
that's because the backend is called as well (dvips) ; the latest
version has a --nobackend option
- End forwarded message -
- Forwarded message from Mike Bird [EMAIL PROTECTED] -
From: Mike Bird [EMAIL PROTECTED]
Subject: Is texmfstart secure?
To: [EMAIL PROTECTED]
Date: Tue, 24 Oct 2006 21:08:53 -0700
Package: context 2006.08.08-0.4
If anyone who knows Ruby has time, can you tell if texmfstart is
secure? I was really surprised to see client-server code. Even
localhost services can lead to privilege escalation if not careful.
hm, if you don't invoke that code it's not used so there can hardly be a
leak then;
the server/client code is a bit experimental and is related to
distributed ruby code; imagine a situation where one has many (frozen)
tex trees on a server that is used for automated tex processing; in that
case, instead of calling kpsewhich each time, a service will keep the
file databases (for multiple trees) in memory etc etc ; as said, the
average user never enters this code, and it's not even loaded when your
system is not explicitly configured to do so
For example, /usr/share/texmf/scripts/context/ruby/texmfstart.rb
contains the following. I'm not a Ruby programmer but the comment
leads me to think there is a potential problem here:
# danger lurking
buffer = ' ' * 260
length = filemethod.call(filename,buffer,buffer.size)
if length0 then
return buffer.slice(0..length-1)
this has to do with windows long/short names and this branch is never
entered under unix ; also, buffer is just a string and has nothing to do
with buffers that produce those buffer overflows
It looks like PRAGMA is trying to reinvent kpsewhich, integrate internet
well, it's mostly a wrapper around kpsewhich; it would be natural to
have kpse as a library but (1) it's not stable [api cq. names changes]
and i don't see a stable kpse lib usable in script languages show up;
(and yes: i rewrote kpse in ruby, and surprise, in some case it even
runs faster than the c version); consider that in context there can be
runs with (say) 400 calls to metapost and then it really pays off to
bypass this ls-r loading
explorer, launch editors, and do a whole bunch of other stuff I haven't
this launching is only used when one starts documentation -- we use this
in editors: context sensitive help started by a few keystrokes
another option is to use file associations but that has some disadvantaged
anyhow, i see no security risks here since all happens inside the tex
domain; i don't need tex to crash an internet browser (on any system) -)
figured out. texexec should be a simple wrapper around tex or pdftex
but it works via texmfstart.rb which is 2541 lines of Ruby - and that's
a lot of Ruby. It may all be wonderful (I am not a Ruby programmer) but
well, if kpse* would have evolved ... sure, but it didn't; also, since i
run tex on windows, linux and macosx, i want one launcher for all of
them, not all kind of os dependent scripts
it makes me nervous.
well, i would be more worried about tons of cryptic perl code, even if
i've written it myself, after a few years i can no longer figure out
what it does;
Is an older/simpler texexec still available?
there is still texexec.pl (will always be around) but i will no longer
develop the perl scripts
Hans
--
-
Hans Hagen | PRAGMA ADE
Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
tel: 038 477 53 69 | fax: 038 477 53 74 | www.pragma-ade.com
| www.pragma-pod.nl
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