Re: Re: [ANN] Org-babel integrated into Org-mode

["Eric Schulte" <schulte.eric@gmail.com>]

Hi Carsten, Matt, Scott,

Carsten Dominik <carsten.dominik@gmail.com> writes:

> Hi Matt, hi Eric,
>
> Matt, thanks a lot for bringing this up.  This is indeed a very
> important and serious issue.  We need to address it.  We need to
> step back and reconsider this carefully.
>
> Don't get me wrong, I absolutely think that Org Babel should give
> you enough rope to hang yourself.  But we have to make sure that
> this will not happen to a happy and unsuspecting Org mode, or even
> an unsuspecting Emacs user who by chance opens a file with extension
> .org.
>
> I remember very well when  first realized that shell links could
> really affect you badly.  It scared me.
>
> You main proposal was to make Org Babel an optional module.
> This will not solve the problem fully, I think, because we also
> don't want that people who turn it on automatically commit
> to potentially dangerous operations.  There is a lot of good stuff
> in Babel which has nothing to do with code evaluation.
>
> Here is what I propose (several items are similar to what Eric proposes)
>
> 1. A new variable org-turn-on-babel.  We can discuss the default.
>    If it is nil, org-babel should not be loaded.
>    A default of t would be fine with me if we implement other
>    measures listed below.
>

This sounds like a good idea to me, and it should address Matt's desire
for enabling minimal Org-mode installs.  I would like this to default to
t, so that new users can try out Org-babel without overmuch effort.

>
> 2. As Eric proposes, a variable similar to org-confirm-shell-link-
>    function
>    This should by default query for confirmation on any org-babel
>    code execution, and can be configured to shut up by people who know
>    what they are doing.
>

Sounds good, I think this is a reasonable safety measure.

>
> 3. Not loading emacs lisp evaluation by default.
>

I would push back on this point.  Largely because we have now crossed
the like to where it is impossible to play with a code block w/o first
dropping down to your configuration files, and evaluating require
statements.

>
> 4. A new key in the babel keymap for org-babel-execute-code-block,
>    for example `C-c C-v e'.  This should be documented as the default
>    key for this operation.
>

Hmm, I'm less enthusiastic about this point and point 5.  I really like
how 'C-c C-c' naturally does whatever-I-want given the context in which
it's called, and I wouldn't want to lose that intuitiveness.  Similarly
'C-c C-o' currently opens the results of a code block, I also find this
very appealing as it allows for a uniform top-level interface across an
Org-mode document, be it a code block or a link.

Here are my reasons why I think leaving this keybinding is safe.

1) Unlike with shell/elisp links, the contents of code blocks is almost
   always visible right under the user's point.  So it is less likely to
   evaluate something w/o having any idea what you are evaluating.

2) Adding a protection variable (e.g. org-confirm-babel-eval) means that
   the only users who could potentially evaluate a code block with a
   slip of the fingers would be users who have explicitly said that they
   want to be able to easily run code blocks without confirmation.

3) Emacs exposes a number of entry points into code evaluation.  M-!
   allows users to run shell commands, C-M-x evaluate the elisp at
   point, and these have not caused problems in the past.

>
> 5. Removing org-babel-execute-code-block from `C-c C-c'.  Inclusion
>    should be optional.
>
> 6. A section in the manual on code execution and associated security
>    risks in Org mode.  This is not only about babel, but also about
>    org-eval, org-eval-light, shell links and elisp links.  I have meant
>    to write this section for a long time and would be willing to
>    draft it. We could then refer to this section from a couple of
>    places in the docs, without cluttering the docs with disclaimers.
>

This sounds like a very good idea.  I'd be happy to help write such a
section.

>
> The reason for 4 and 5 is that I believe Org-mode users are trained
> to blindly press `C-c C-c' whenever they want to update something at
> point.  Matt's example of a blog post about `rm -rf' is a very
> realistic example for bad code being evaluated by mistake, not even
> due to malicious cations.  I belive that a special key for this
> action would gove a good measure of protection.
>

As I mentioned, I personally feel that an org-confirm-babel-eval
variable is sufficient protection.  I think it's safe to assume that if
a user has explicitly customized that variable, then they know what
they're doing and trust themselves to execute code responsibly.  I think
it's likely that the casual Org-babel user would never customize this
variable, which seems to me entirely appropriate.

>
> This is what I think - please let me know if you think I am overdoing
> it.
>

So to summarize, I think that the combination of (1), (2) and (6),
should be sufficient to protect users from accidental code evaluation.
Please let me know what you think, I am of course looking to compromise
and I fully understand that the general consensus may be that we need
more layers of protection.

Best -- Eric

>
> - Carsten
>
>
> On Jun 29, 2010, at 8:23 PM, Matt Lundin wrote:
>
>> Hi Eric,
>>
>> Thanks again for all the work that you, Dan, and Tom have put into
>> org-babel. I'm glad to see it become part of org-mode!
>>
>> "Eric Schulte" <schulte.eric@gmail.com> writes:
>>
>>> 2) Babel will now be loaded by default along with the rest of Org-
>>> mode.
>>>   This means that *everyone* currently using babel will need to
>>> change
>>>   their Emacs config and remove the (require 'org-babel-int) and/or
>>>   (require 'org-babel) lines.
>>
>> I would like to request that org-babel be made an optional module. I
>> ask
>> this as someone who uses org-babel regularly. Here are my reasons:
>>
>>  - Org-babel adds rather specific and complex functionality to org-
>> mode
>>    that those who use it as a simple outliner and todo manager do not
>>    require. (In other words, an option to turn it off might be nice
>> for
>>    those who are worried about "feature creep.")
>>
>>  - Org-babel increases the risk of accidentally executing malicious or
>>    dangerous code when typing C-c C-c on a src block or exporting a
>>    file. Perhaps users should activate it only after they understand
>>    the risks.
>>
>>    + For instance, I might write a blog post warning about the dangers
>>      of typing "rm -rf ~/". If I put this between #+begin_src sh
>>      and #+end_src and unthinkingly hit C-c C-c, I would be in
>> trouble.
>>      I believe this is the reason for the variables
>>      org-confirm-shell-link-function and
>>      org-confirm-elisp-link-function.
>>
>>    + This is admitted a bit far-fetched as an example, as it would
>>      require one to have loaded ob-sh.el. But since elisp execution is
>>      activated by default, there remain opportunities for unwittingly
>>      executing code that is meant for other purposes (e.g., warnings,
>>      examples, etc.).
>>
>>>   Support for evaluating emacs-lisp code blocks is loaded by default.
>>>   All other languages will need to be required explicitly.  To
>>> conform
>>>   to Emacs filename specifications all language require lines have
>>> been
>>>   shortened from e.g.
>>>
>>>   (require 'org-babel-sh)
>>>
>>>   to
>>>
>>>   (require 'ob-sh)
>>
>> When I run make clean && make && make install I find that the language
>> directory is not installed. Does the langs directory require a manual
>> installation?
>>
>> Also, with make install, the ob-* files are installed on the same
>> level
>> as the org-files, yet lines 108-114 in org.el indicate that they
>> should
>> be installed in a babel subdirectory.
>>
>> Thanks!
>> Matt
>>
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>
> - Carsten