Delivery-date: Tue, 18 Jun 2024 04:46:34 -0700
Received-SPF: pass (google.com: domain of darosior@protonmail.com designates 185.70.43.167 as permitted sender) client-ip=185.70.43.167;
Date: Tue, 18 Jun 2024 08:13:44 +0000
To: Eric Voskuil <eric@voskuil.org>
From: "'Antoine Poinsot' via Bitcoin Development Mailing List" <bitcoindev@googlegroups.com>
Cc: Bitcoin Development Mailing List <bitcoindev@googlegroups.com>
Subject: Re: [bitcoindev] Re: Great Consensus Cleanup Revival
Message-ID: <heKH68GFJr4Zuf6lBozPJrb-StyBJPMNvmZL0xvKFBnBGVA3fVSgTLdWc-_8igYWX8z3zCGvzflH-CsRv0QCJQcfwizNyYXlBJa_Kteb2zg=@protonmail.com>
In-Reply-To: <72e83c31-408f-4c13-bff5-bf0789302e23n@googlegroups.com>
References: <gnM89sIQ7MhDgI62JciQEGy63DassEv7YZAMhj0IEuIo0EdnafykF6RH4OqjTTHIHsIoZvC2MnTUzJI7EfET4o-UQoD-XAQRDcct994VarE=@protonmail.com> <72e83c31-408f-4c13-bff5-bf0789302e23n@googlegroups.com>
Feedback-ID: 7060259:user:proton
MIME-Version: 1.0
Content-Type: multipart/alternative;
 boundary="b1_7ZstBLrbDOiDQNkGaD5e34Z7R11hdS9N6eDIC7GyxqU"
Reply-To: Antoine Poinsot <darosior@protonmail.com>
Precedence: list
Mailing-list: list bitcoindev@googlegroups.com; contact bitcoindev+owners@googlegroups.com

This is a multi-part message in MIME format.

--b1_7ZstBLrbDOiDQNkGaD5e34Z7R11hdS9N6eDIC7GyxqU
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

Hi Eric,

It is. This is what is implemented in Bitcoin Core, see [this snippet](http=
s://github.com/bitcoin/bitcoin/blob/41544b8f96dbc9c6b8998acd6522200d67cdc16=
d/src/validation.cpp#L4547-L4552) and section 4.1 of the document you refer=
ence:

> Another check that was also being done in CheckBlock() relates to the coi=
nbase transaction: if the first transaction in a block fails the required s=
tructure of a coinbase =E2=80=93 one input, with previous output hash of al=
l zeros and index of all ones =E2=80=93 then the block will fail validation=
. The side effect of this test being in CheckBlock() was that even though t=
he block malleability discussed in section 3.1 was unknown, we were effecti=
vely protected against it =E2=80=93 as described above, it would take at le=
ast 224 bits of work to produce a malleated block that passed the coinbase =
check.

Best,
Antoine
On Tuesday, June 18th, 2024 at 12:15 AM, Eric Voskuil <eric@voskuil.org> wr=
ote:

> Hi Antoine,
>
> Regarding potential malleability pertaining to blocks with only 64 byte t=
ransactions, why is not a deserialization phase check for the coinbase inpu=
t as a null point not sufficient mitigation (computational infeasibility) f=
or any implementation that desires to perform permanent invalidity marking?
>
> Best,
> Eric
>
> ref: [Weaknesses in Bitcoin=E2=80=99s Merkle Root Construction](https://l=
ists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20190225/a27d883=
7/attachment-0001.pdf)
>
> --
> You received this message because you are subscribed to the Google Groups=
 "Bitcoin Development Mailing List" group.
> To unsubscribe from this group and stop receiving emails from it, send an=
 email to bitcoindev+unsubscribe@googlegroups.com.
> To view this discussion on the web visit https://groups.google.com/d/msgi=
d/bitcoindev/72e83c31-408f-4c13-bff5-bf0789302e23n%40googlegroups.com.

--=20
You received this message because you are subscribed to the Google Groups "=
Bitcoin Development Mailing List" group.
To unsubscribe from this group and stop receiving emails from it, send an e=
mail to bitcoindev+unsubscribe@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/=
bitcoindev/heKH68GFJr4Zuf6lBozPJrb-StyBJPMNvmZL0xvKFBnBGVA3fVSgTLdWc-_8igYW=
X8z3zCGvzflH-CsRv0QCJQcfwizNyYXlBJa_Kteb2zg%3D%40protonmail.com.

--b1_7ZstBLrbDOiDQNkGaD5e34Z7R11hdS9N6eDIC7GyxqU
Content-Type: text/html; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable

<div style=3D"font-family: Arial, sans-serif; font-size: 14px; color: rgb(0=
, 0, 0); background-color: rgb(255, 255, 255);">Hi Eric,</div><div style=3D=
"font-family: Arial, sans-serif; font-size: 14px; color: rgb(0, 0, 0); back=
ground-color: rgb(255, 255, 255);"><br></div><div style=3D"font-family: Ari=
al, sans-serif; font-size: 14px; color: rgb(0, 0, 0); background-color: rgb=
(255, 255, 255);">It is. This is what is implemented in Bitcoin Core, see <=
a href=3D"https://github.com/bitcoin/bitcoin/blob/41544b8f96dbc9c6b8998acd6=
522200d67cdc16d/src/validation.cpp#L4547-L4552" title=3D"this snippet">this=
 snippet</a> and section 4.1 of the document you reference:</div><blockquot=
e style=3D"border-color: rgb(200, 200, 200); border-left: 3px solid rgb(200=
, 200, 200); padding-left: 10px; color: rgb(102, 102, 102);"><div style=3D"=
font-family: Arial, sans-serif; font-size: 14px; color: rgb(0, 0, 0); backg=
round-color: rgb(255, 255, 255);"><span>Another check that was also being d=
one in </span><span>CheckBlock() relates to the coinbase transaction: if th=
e first transaction in a </span><span>block fails the required structure of=
 a coinbase =E2=80=93 one input, with previous output </span><span>hash of =
all zeros and index of all ones =E2=80=93 then the block will fail validati=
on. The </span><span>side effect of this test being in CheckBlock() was tha=
t even though the block </span><span>malleability discussed in section 3.1 =
was unknown, we were effectively protected </span><span>against it =E2=80=
=93 as described above, it would take at least 224 bits of work to produce<=
/span><span> a malleated block that passed the coinbase check.</span><br></=
div></blockquote><div style=3D"font-family: Arial, sans-serif; font-size: 1=
4px; color: rgb(0, 0, 0); background-color: rgb(255, 255, 255);"><br></div>=
<div style=3D"font-family: Arial, sans-serif; font-size: 14px; color: rgb(0=
, 0, 0); background-color: rgb(255, 255, 255);">Best,<br></div><div style=
=3D"font-family: Arial, sans-serif; font-size: 14px; color: rgb(0, 0, 0); b=
ackground-color: rgb(255, 255, 255);">Antoine<br></div><div class=3D"proton=
mail_quote">
        On Tuesday, June 18th, 2024 at 12:15 AM, Eric Voskuil &lt;eric@vosk=
uil.org&gt; wrote:<br>
        <blockquote class=3D"protonmail_quote" type=3D"cite">
            Hi Antoine,<br><br>Regarding potential malleability pertaining =
to blocks with only 64 byte transactions, why is not a deserialization phas=
e check for the coinbase input as a null point not sufficient mitigation (c=
omputational infeasibility) for any implementation that desires to perform =
permanent invalidity marking?<br><br>Best,<br>Eric<div><br></div><div>ref: =
<a href=3D"https://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachme=
nts/20190225/a27d8837/attachment-0001.pdf" rel=3D"noreferrer nofollow noope=
ner" target=3D"_blank">Weaknesses in Bitcoin=E2=80=99s Merkle Root Construc=
tion</a><br></div>

<p></p>

-- <br>
You received this message because you are subscribed to the Google Groups "=
Bitcoin Development Mailing List" group.<br>
To unsubscribe from this group and stop receiving emails from it, send an e=
mail to <a href=3D"mailto:bitcoindev+unsubscribe@googlegroups.com" rel=3D"n=
oreferrer nofollow noopener" target=3D"_blank">bitcoindev+unsubscribe@googl=
egroups.com</a>.<br>
To view this discussion on the web visit <a href=3D"https://groups.google.c=
om/d/msgid/bitcoindev/72e83c31-408f-4c13-bff5-bf0789302e23n%40googlegroups.=
com" rel=3D"noreferrer nofollow noopener" target=3D"_blank">https://groups.=
google.com/d/msgid/bitcoindev/72e83c31-408f-4c13-bff5-bf0789302e23n%40googl=
egroups.com</a>.<br>

        </blockquote><br>
    </div>

<p></p>

-- <br />
You received this message because you are subscribed to the Google Groups &=
quot;Bitcoin Development Mailing List&quot; group.<br />
To unsubscribe from this group and stop receiving emails from it, send an e=
mail to <a href=3D"mailto:bitcoindev+unsubscribe@googlegroups.com">bitcoind=
ev+unsubscribe@googlegroups.com</a>.<br />
To view this discussion on the web visit <a href=3D"https://groups.google.c=
om/d/msgid/bitcoindev/heKH68GFJr4Zuf6lBozPJrb-StyBJPMNvmZL0xvKFBnBGVA3fVSgT=
LdWc-_8igYWX8z3zCGvzflH-CsRv0QCJQcfwizNyYXlBJa_Kteb2zg%3D%40protonmail.com?=
utm_medium=3Demail&utm_source=3Dfooter">https://groups.google.com/d/msgid/b=
itcoindev/heKH68GFJr4Zuf6lBozPJrb-StyBJPMNvmZL0xvKFBnBGVA3fVSgTLdWc-_8igYWX=
8z3zCGvzflH-CsRv0QCJQcfwizNyYXlBJa_Kteb2zg%3D%40protonmail.com</a>.<br />

--b1_7ZstBLrbDOiDQNkGaD5e34Z7R11hdS9N6eDIC7GyxqU--