summaryrefslogtreecommitdiff
path: root/42/eee3b62220097f165eb6565267ae617b4416da
blob: c18a75944366297d1f68ff9a2176a3ee9aa2d4c7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
Received: from sog-mx-3.v43.ch3.sourceforge.com ([172.29.43.193]
	helo=mx.sourceforge.net)
	by sfs-ml-1.v29.ch3.sourceforge.com with esmtp (Exim 4.76)
	(envelope-from <gavinandresen@gmail.com>) id 1UXAOa-00071g-RQ
	for bitcoin-development@lists.sourceforge.net;
	Tue, 30 Apr 2013 13:15:00 +0000
Received-SPF: pass (sog-mx-3.v43.ch3.sourceforge.com: domain of gmail.com
	designates 74.125.82.45 as permitted sender)
	client-ip=74.125.82.45; envelope-from=gavinandresen@gmail.com;
	helo=mail-wg0-f45.google.com; 
Received: from mail-wg0-f45.google.com ([74.125.82.45])
	by sog-mx-3.v43.ch3.sourceforge.com with esmtps (TLSv1:RC4-SHA:128)
	(Exim 4.76) id 1UXAOa-0008H8-0a
	for bitcoin-development@lists.sourceforge.net;
	Tue, 30 Apr 2013 13:15:00 +0000
Received: by mail-wg0-f45.google.com with SMTP id l18so439417wgh.0
	for <bitcoin-development@lists.sourceforge.net>;
	Tue, 30 Apr 2013 06:14:53 -0700 (PDT)
MIME-Version: 1.0
X-Received: by 10.180.212.3 with SMTP id ng3mr3872528wic.22.1367327693833;
	Tue, 30 Apr 2013 06:14:53 -0700 (PDT)
Received: by 10.194.143.36 with HTTP; Tue, 30 Apr 2013 06:14:53 -0700 (PDT)
In-Reply-To: <517FABE6.8020205@bitonic.nl>
References: <CABsx9T3egz=7YNOrgx7WsfSthLfN2gfE60YfPEv8096vyErBqg@mail.gmail.com>
	<20130428180304.GA30115@crunch>
	<CA+CODZEiWTrmFzrMi2Mi0qtH3dWO5UWx_j09iUwV2qm1O=3o0A@mail.gmail.com>
	<CANEZrP2JDc244xvR0ayM700Vy_h3G=aAUUgfxtOcxd0ZeB9b8g@mail.gmail.com>
	<517FABE6.8020205@bitonic.nl>
Date: Tue, 30 Apr 2013 09:14:53 -0400
Message-ID: <CABsx9T0TTZC0EOO3ZLa3cTWhpYJaEVrQ1vO8ofaGbcDJRmfWYA@mail.gmail.com>
From: Gavin Andresen <gavinandresen@gmail.com>
To: Jouke Hofman <jouke@bitonic.nl>
Content-Type: multipart/alternative; boundary=001a11c356f47b90f904db93c91e
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
	(gavinandresen[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: 1UXAOa-0008H8-0a
Cc: bitcoin-development@lists.sourceforge.net
Subject: Re: [Bitcoin-development] Cold Signing Payment Requests
X-BeenThere: bitcoin-development@lists.sourceforge.net
X-Mailman-Version: 2.1.9
Precedence: list
List-Id: <bitcoin-development.lists.sourceforge.net>
List-Unsubscribe: <https://lists.sourceforge.net/lists/listinfo/bitcoin-development>,
	<mailto:bitcoin-development-request@lists.sourceforge.net?subject=unsubscribe>
List-Archive: <http://sourceforge.net/mailarchive/forum.php?forum_name=bitcoin-development>
List-Post: <mailto:bitcoin-development@lists.sourceforge.net>
List-Help: <mailto:bitcoin-development-request@lists.sourceforge.net?subject=help>
List-Subscribe: <https://lists.sourceforge.net/lists/listinfo/bitcoin-development>,
	<mailto:bitcoin-development-request@lists.sourceforge.net?subject=subscribe>
X-List-Received-Date: Tue, 30 Apr 2013 13:15:01 -0000

--001a11c356f47b90f904db93c91e
Content-Type: text/plain; charset=ISO-8859-1

RE: Timo's proposal for protecting the refund address:

Seems to me there are two risks:

1) The risk that the merchant's web server will be compromised and the
attacker will redirect refunds
2) The risk that the merchant will miss payments because they miss a POST
to the payment_url (maybe the customer's machine crashes during the HTTPS
handshake)

If payments are a lot more common than refunds, then (2) will outweigh (1).

I also think an attacker who compromises the front-end web server would
probably just have it start generating plain-old pay-to-bitcoin-address
payment requests, and hope that lots of customers pay them directly before
the attack is discovered.

-- 
--
Gavin Andresen

--001a11c356f47b90f904db93c91e
Content-Type: text/html; charset=ISO-8859-1
Content-Transfer-Encoding: quoted-printable

<div>RE: Timo&#39;s proposal for protecting the refund address:</div><div><=
br></div><div>Seems to me there are two risks:</div><div><br></div><div>1) =
The risk that the merchant&#39;s web server will be compromised and the att=
acker will redirect refunds</div>
<div>2) The risk that the merchant will miss payments because they miss a P=
OST to the payment_url (maybe the customer&#39;s machine crashes during the=
 HTTPS handshake)</div><div><br></div><div>If payments are a lot more commo=
n than refunds, then (2) will outweigh (1).</div>
<div><br></div><div>I also think an attacker who compromises the front-end =
web server would probably just have it start generating plain-old pay-to-bi=
tcoin-address payment requests, and hope that lots of customers pay them di=
rectly before the attack is discovered.</div>
<div><br></div><div>-- <br>--<br>Gavin Andresen<br>
</div>

--001a11c356f47b90f904db93c91e--