public inbox for bitcoindev@googlegroups.com
 help / color / mirror / Atom feed
From: Jeremy <jlrubin@mit.edu>
To: Steve Davis <steven.charles.davis@gmail.com>,
	Bitcoin Protocol Discussion
	<bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] Script Abuse Potential?
Date: Mon, 2 Jan 2017 22:27:44 -0500	[thread overview]
Message-ID: <CAD5xwhjHFzFzKws10TG-XioZoRVZ_oZbMF_xDOy5xNWtzFTsEw@mail.gmail.com> (raw)
In-Reply-To: <400152B9-1838-432A-829E-13E4FC54320C@gmail.com>

[-- Attachment #1: Type: text/plain, Size: 1089 bytes --]

It is an unfortunate script, but can't actually
​do
 that much
​ it seems​
. The MAX_SCRIPT_ELEMENT_SIZE = 520 Bytes.
​ Thus, it would seem the worst you could do with this would be to
(10000-520*2)*520*2
bytes  ~=~ 10 MB.

​Much more concerning would be the op_dup/op_cat style bug, which under a
similar script ​would certainly cause out of memory errors :)



--
@JeremyRubin <https://twitter.com/JeremyRubin>
<https://twitter.com/JeremyRubin>

On Mon, Jan 2, 2017 at 4:39 PM, Steve Davis via bitcoin-dev <
bitcoin-dev@lists.linuxfoundation.org> wrote:

> Hi all,
>
> Suppose someone were to use the following pk_script:
>
> [op_2dup, op_2dup, op_2dup, op_2dup, op_2dup, ...(to limit)...,
> op_2dup, op_hash160, <addr_hash>, op_equalverify, op_checksig]
>
> This still seems to be valid AFAICS, and may be a potential attack vector?
>
> Thanks.
>
>
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>
>

[-- Attachment #2: Type: text/html, Size: 3428 bytes --]

  reply	other threads:[~2017-01-03  3:33 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <mailman.11263.1483391161.31141.bitcoin-dev@lists.linuxfoundation.org>
2017-01-02 21:39 ` [bitcoin-dev] Script Abuse Potential? Steve Davis
2017-01-03  3:27   ` Jeremy [this message]
2017-01-03  3:39     ` Johnson Lau
2017-01-03  5:04       ` Russell O'Connor
2017-01-04  0:13       ` Jeremy
2017-01-04  3:13         ` Russell O'Connor
2017-01-04 14:45           ` Jorge Timón
2017-01-05 16:22             ` Jeremy

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=CAD5xwhjHFzFzKws10TG-XioZoRVZ_oZbMF_xDOy5xNWtzFTsEw@mail.gmail.com \
    --to=jlrubin@mit.edu \
    --cc=bitcoin-dev@lists.linuxfoundation.org \
    --cc=steven.charles.davis@gmail.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox