Received: from sog-mx-1.v43.ch3.sourceforge.com ([172.29.43.191] helo=mx.sourceforge.net) by sfs-ml-3.v29.ch3.sourceforge.com with esmtp (Exim 4.76) (envelope-from ) id 1UMmeK-00053I-3j for bitcoin-development@lists.sourceforge.net; Mon, 01 Apr 2013 21:52:20 +0000 Received-SPF: pass (sog-mx-1.v43.ch3.sourceforge.com: domain of gmail.com designates 209.85.217.181 as permitted sender) client-ip=209.85.217.181; envelope-from=melvincarvalho@gmail.com; helo=mail-lb0-f181.google.com; Received: from mail-lb0-f181.google.com ([209.85.217.181]) by sog-mx-1.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128) (Exim 4.76) id 1UMmeI-0005VA-HC for bitcoin-development@lists.sourceforge.net; Mon, 01 Apr 2013 21:52:20 +0000 Received: by mail-lb0-f181.google.com with SMTP id r11so2371205lbv.12 for ; Mon, 01 Apr 2013 14:52:11 -0700 (PDT) MIME-Version: 1.0 X-Received: by 10.112.43.232 with SMTP id z8mr6506515lbl.135.1364853131793; Mon, 01 Apr 2013 14:52:11 -0700 (PDT) Received: by 10.112.143.38 with HTTP; Mon, 1 Apr 2013 14:52:11 -0700 (PDT) In-Reply-To: References: Date: Mon, 1 Apr 2013 23:52:11 +0200 Message-ID: From: Melvin Carvalho To: Petr Praus Content-Type: multipart/alternative; boundary=e0cb4efe34001760f404d953a2c9 X-Spam-Score: -0.6 (/) X-Spam-Report: Spam Filtering performed by mx.sourceforge.net. See http://spamassassin.org/tag/ for more details. -1.5 SPF_CHECK_PASS SPF reports sender host as permitted sender for sender-domain 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (melvincarvalho[at]gmail.com) -0.0 SPF_PASS SPF: sender matches SPF record 1.0 HTML_MESSAGE BODY: HTML included in message -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature X-Headers-End: 1UMmeI-0005VA-HC Cc: Bitcoin Dev Subject: Re: [Bitcoin-development] bitcoin pull requests X-BeenThere: bitcoin-development@lists.sourceforge.net X-Mailman-Version: 2.1.9 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 01 Apr 2013 21:52:20 -0000 --e0cb4efe34001760f404d953a2c9 Content-Type: text/plain; charset=ISO-8859-1 On 1 April 2013 20:28, Petr Praus wrote: > An attacker would have to find a collision between two specific pieces of > code - his malicious code and a useful innoculous code that would be > accepted as pull request. This is the second, much harder case in the > birthday problem. When people talk about SHA-1 being broken they actually > mean the first case in the birthday problem - find any two arbitrary values > that hash to the same value. So, no I don't think it's a feasible attack > vector any time soon. > > Besides, with that kind of hashing power, it might be more feasible to > cause problems in the chain by e.g. constantly splitting it. > OK, maybe im being *way* too paranoid here ... but what if someone had access to github, could they replace one file with one they had prepared at some point? > > > On 1 April 2013 03:26, Melvin Carvalho wrote: > >> I was just looking at: >> >> https://bitcointalk.org/index.php?topic=4571.0 >> >> I'm just curious if there is a possible attack vector here based on the >> fact that git uses the relatively week SHA1 >> >> Could a seemingly innocuous pull request generate another file with a >> backdoor/nonce combination that slips under the radar? >> >> Apologies if this has come up before ... >> >> >> ------------------------------------------------------------------------------ >> Own the Future-Intel® Level Up Game Demo Contest 2013 >> Rise to greatness in Intel's independent game demo contest. >> Compete for recognition, cash, and the chance to get your game >> on Steam. $5K grand prize plus 10 genre and skill prizes. >> Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d >> _______________________________________________ >> Bitcoin-development mailing list >> Bitcoin-development@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/bitcoin-development >> >> > --e0cb4efe34001760f404d953a2c9 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable



On 1 April 2013 20:28, Petr Praus <petr@praus.net> wrot= e:
An attacker would have to find a collision between two spe= cific pieces of code - his malicious code and a useful innoculous code that= would be accepted as pull request. This is the second, much harder case in= the birthday problem. When people talk about SHA-1 being broken they actua= lly mean the first case in the birthday problem - find any two arbitrary va= lues that hash to the same value. So, no I don't think it's a feasi= ble attack vector any time soon.

Besides, with that kind of hashing power, it might be more f= easible to cause problems in the chain by e.g. constantly splitting it.

OK, maybe im being *way* too paran= oid here ... but what if someone had access to github, could they replace o= ne file with one they had prepared at some point?
=A0


On 1 April 2013 03:26, Melvin Carvalho <melvincarvalho@gmail.com> wrote:
I'm just curio= us if there is a possible attack vector here based on the fact that git use= s the relatively week SHA1

Could a seemingly innocuous pull request generate another file wi= th a backdoor/nonce combination that slips under the radar?

Ap= ologies if this has come up before ...

-----------------------------------------------------------= -------------------
Own the Future-Intel&reg; Level Up Game Demo Contest 2013
Rise to greatness in Intel's independent game demo contest.
Compete for recognition, cash, and the chance to get your game
on Steam. $5K grand prize plus 10 genre and skill prizes.
Submit your demo by 6/6/13. http://p.sf.net/sfu/intel_levelupd2d
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Bitcoin-development@lists.sourceforge.net
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