Re: Sandboxing Python

Path	csiph.com!news.swapon.de!news.roellig-ltd.de!open-news-network.org!border2.nntp.ams1.giganews.com!nntp.giganews.com!newsfeed.xs4all.nl!newsfeed8.news.xs4all.nl!nzpost1.xs4all.net!not-for-mail
Return-Path	<rosuav@gmail.com>
X-Original-To	python-list@python.org
Delivered-To	python-list@mail.python.org
X-Spam-Status	OK 0.008
X-Spam-Evidence	'H': 0.98; 'S': 0.00; 'subject:Python': 0.05; 'properly.': 0.07; 'cc:addr:python-list': 0.09; 'is': 0.09; 'builtins': 0.09; 'operator,': 0.09; 'do,': 0.15; '"use': 0.16; '23,': 0.16; 'attributes.': 0.16; 'eval': 0.16; 'from:addr:rosuav': 0.16; 'from:name:chris angelico': 0.16; 'literal,': 0.16; 'stuff.': 0.16; 'wrote:': 0.16; '2015': 0.20; 'cc:2**0': 0.20; 'cc:addr:python.org': 0.20; 'aug': 0.20; 'proposed': 0.20; 'lawrence': 0.22; 'please?': 0.22; 'sorry,': 0.22; 'am,': 0.23; 'header:In-Reply-To:1': 0.24; 'message- id:@mail.gmail.com': 0.27; 'end,': 0.29; "i'm": 0.30; 'code': 0.30; "can't": 0.32; 'maybe': 0.33; 'received:google.com': 0.35; 'but': 0.36; 'there': 0.36; 'subject:: ': 0.37; 'mark': 0.40; 'still': 0.40; 'more': 0.63; 'safe': 0.63; 'believe': 0.66; 'here': 0.66; 'talking': 0.67; 'url:r': 0.67; 'subject': 0.70; 'led': 0.72; 'chrisa': 0.84; 'to:none': 0.91; 'safe.': 0.93; 'url:comments': 0.93
DKIM-Signature	v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:cc :content-type; bh=JkBrPgrbHfSHUUTT11VVaATkug23nvGdwonGv5DMVgw=; b=weQ5PSKICCVD7g1YeFTSYeyAw/bd6+pHnoFhLvwJaTF8MgCZ/Iigk04r4m6/pD/gZa dtikJOZxbzEIeOiWIXfKjBx+QSjjrCb2r+28P+Ivamf2+9kQuZEhchf6sBSNsfJkn9v0 aWOxVBGobrJ93NAWA2YLIlyw9n52h2WoaSuXBfRwfIKYfbtUqBuS+9JPNJ1HGgw9fAdF Y/FOFx5s0s2Pyx4kFUPPCBSFeo1bxZS+OkhHzFTp9DQSkuz6kfZfF0u2tVH4YyIN8+PY roWgrxZYSuf7Tuq9EBLoBA6VTxqckrT+JluMCc0W9WJu50nSeGuzuB/4dGIyc3pnZkTN DLPQ==
MIME-Version	1.0
X-Received	by 10.107.12.166 with SMTP id 38mr12420073iom.157.1440287099188; Sat, 22 Aug 2015 16:44:59 -0700 (PDT)
In-Reply-To	<mrb0eh$2md$1@ger.gmane.org>
References	<mrb0eh$2md$1@ger.gmane.org>
Date	Sun, 23 Aug 2015 09:44:59 +1000
Subject	Re: Sandboxing Python
From	Chris Angelico <rosuav@gmail.com>
Cc	"python-list@python.org" <python-list@python.org>
Content-Type	text/plain; charset=UTF-8
X-BeenThere	python-list@python.org
X-Mailman-Version	2.1.20+
Precedence	list
List-Id	General discussion list for the Python programming language <python-list.python.org>
List-Unsubscribe	<https://mail.python.org/mailman/options/python-list>, <mailto:python-list-request@python.org?subject=unsubscribe>
List-Archive	<http://mail.python.org/pipermail/python-list/>
List-Post	<mailto:python-list@python.org>
List-Help	<mailto:python-list-request@python.org?subject=help>
List-Subscribe	<https://mail.python.org/mailman/listinfo/python-list>, <mailto:python-list-request@python.org?subject=subscribe>
Newsgroups	comp.lang.python
Message-ID	<mailman.20.1440287102.17298.python-list@python.org> (permalink)
Lines	23
NNTP-Posting-Host	2001:888:2000:d::a6
X-Trace	1440287102 news.xs4all.nl 23810 [2001:888:2000:d::a6]:35252
X-Complaints-To	abuse@xs4all.nl
Xref	csiph.com comp.lang.python:95570

Show key headers only | View raw

On Sun, Aug 23, 2015 at 9:25 AM, Mark Lawrence <breamoreboy@yahoo.co.uk> wrote:
> I was always led to believe that the subject was a difficult thing to do,
> but here
> https://www.reddit.com/r/learnpython/comments/3huz4x/how_to_do_math_inside_raw_input/
> is a safe solution in only 23 characters, or are there any discernable flaws
> in it?

I'm sorry, I can't see which solution you're talking about there -
maybe I just don't know how to read reddit properly. Can you paste the
proposed code please?

The best I can see there is "use eval but with no builtins". That's
fundamentally flawed because you don't need builtins to break stuff.
All you need is a literal, from which you can snag everything else via
its attributes.

However, for this situation, I would be recommending ast.literal_eval,
which *is* safe. It's a lot more powerful than "split it into number,
operator, number" as mentioned at the end, but still can't majorly
break anything.

ChrisA

Back to comp.lang.python | Previous | Next | Find similar | Unroll thread

Thread

Re: Sandboxing Python Chris Angelico <rosuav@gmail.com> - 2015-08-23 09:44 +1000

csiph-web