MIME-Version: 1.0
In-Reply-To: <CAK9dXBSg+wzAZw7_xPXRVvx1uZzjAEE8nuvj0vkdSGD-yTfwhQ@mail.gmail.com>
References: <CAK9dXBSg+wzAZw7_xPXRVvx1uZzjAEE8nuvj0vkdSGD-yTfwhQ@mail.gmail.com>
From: =?UTF-8?Q?Hampus_Sj=C3=B6berg?= <hampus.sjoberg@gmail.com>
Date: Fri, 19 May 2017 15:13:03 +0200
Message-ID: <CAFMkqK8u37rLfwdx_d2oX0a9p2J=vvGcmSkNfj-LS2krOb+f6w@mail.gmail.com>
To: Mark Boldyrev <markboldyrev@gmail.com>
Content-Type: multipart/alternative; boundary="001a1136f3d615c2d5054fe04800"
Cc: Bitcoin Protocol Discussion <bitcoin-dev@lists.linuxfoundation.org>
Subject: Re: [bitcoin-dev] A proposal to reintroduce the disabled script
	opcodes
Precedence: list

--001a1136f3d615c2d5054fe04800
Content-Type: text/plain; charset="UTF-8"

AFAICT, re-enabling these old OP-codes would require a hardfork.

If we had SegWit enabled, we could via a soft fork allocate new OP-codes
for the same functionality (by introducing a new version of Script).
I believe the Elements alpha project has been experimenting with
re-enabling old OP-codes: https://elementsproject.org/elements/opcodes/

2017-05-19 8:07 GMT+02:00 Mark Boldyrev via bitcoin-dev <
bitcoin-dev@lists.linuxfoundation.org>:

> Back in 2010, there was a bug found in Core which allowed
> denial-of-service attacks due to the software crashing on some machines
> while executing a script - see CVE-2010-537.
> I believe the removed ("disabled") opcodes should be re-introduced along
> with a standardized behavior definition.
> For example, when execution of an opcode results in an arithmetic error,
> such as OP_DIV with a zero divisor, the script should exit and fail.
> The string splice opcodes should also check their arguments for
> correctness, etc.
>
> These opcodes would enhance the flexibility of scripts and allow
> sophisticated native smart contracts to be created.
>
> _______________________________________________
> bitcoin-dev mailing list
> bitcoin-dev@lists.linuxfoundation.org
> https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
>
>

--001a1136f3d615c2d5054fe04800
Content-Type: text/html; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr"><div><div>AFAICT, re-enabling these old OP-codes would req=
uire a hardfork.<br><br></div>If we had SegWit enabled, we could via a soft=
 fork allocate new OP-codes for the same functionality (by introducing a ne=
w version of Script).<br></div>I believe the Elements alpha project has bee=
n experimenting with re-enabling old OP-codes: <a href=3D"https://elementsp=
roject.org/elements/opcodes/">https://elementsproject.org/elements/opcodes/=
</a><br></div><div class=3D"gmail_extra"><br><div class=3D"gmail_quote">201=
7-05-19 8:07 GMT+02:00 Mark Boldyrev via bitcoin-dev <span dir=3D"ltr">&lt;=
<a href=3D"mailto:bitcoin-dev@lists.linuxfoundation.org" target=3D"_blank">=
bitcoin-dev@lists.linuxfoundation.org</a>&gt;</span>:<br><blockquote class=
=3D"gmail_quote" style=3D"margin:0 0 0 .8ex;border-left:1px #ccc solid;padd=
ing-left:1ex"><div dir=3D"ltr"><span style=3D"font-size:12.8px">Back in 201=
0, there was a bug found in Core which allowed denial-of-service attacks du=
e to the software crashing on some machines while executing a script - see =
CVE-2010-537.</span><div style=3D"font-size:12.8px">I believe the removed (=
&quot;disabled&quot;) opcodes should be re-introduced along with a standard=
ized behavior definition.</div><div style=3D"font-size:12.8px">For example,=
 when execution of an opcode results in an arithmetic error, such as OP_DIV=
 with a zero divisor, the script should exit and fail.</div><div style=3D"f=
ont-size:12.8px">The string splice opcodes should also check their argument=
s for correctness, etc.</div><div style=3D"font-size:12.8px"><br></div><div=
 style=3D"font-size:12.8px">These opcodes would enhance the flexibility of =
scripts and allow sophisticated native smart contracts to be created.</div>=
</div>
<br>______________________________<wbr>_________________<br>
bitcoin-dev mailing list<br>
<a href=3D"mailto:bitcoin-dev@lists.linuxfoundation.org">bitcoin-dev@lists.=
<wbr>linuxfoundation.org</a><br>
<a href=3D"https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev" =
rel=3D"noreferrer" target=3D"_blank">https://lists.linuxfoundation.<wbr>org=
/mailman/listinfo/bitcoin-<wbr>dev</a><br>
<br></blockquote></div><br></div>

--001a1136f3d615c2d5054fe04800--