[tor-commits] [bridgedb/master] Add unittest for MailMessage.getRecipient() which exposes 2.5 bugs.
isis at torproject.org
isis at torproject.org
Fri Jun 6 23:39:14 UTC 2014
commit f1b7d03cf1e2dfbb9e11897d0bb07b43f5ad33e5
Author: Isis Lovecruft <isis at torproject.org>
Date: Wed May 21 15:02:17 2014 +0000
Add unittest for MailMessage.getRecipient() which exposes 2.5 bugs.
Bug #1:
-------
BridgeDB's current code will accept an incoming email with a
'To: givemebridges at serious.ly'
header. However, BridgeDB's reply will still contain:
'From: bridges at torproject.org'
Obviously, it *shouldn't* be possible for any email whose SMTP RCPT TO
domain is 'serious.ly' to actually end up in BridgeDB's mail
queue. Though, if the outside SMTP layer is sent to
'[bridges|ponticum].torproject.org' (with MAIL FROM a gmail/yahoo
address), these messages still end up in BridgeDB's mail queue.
The following netcat session demonstrates that this is possible:
∃!isisⒶwintermute:(master *$=)~ ∴ torsocks nc bridges.torproject.org 25
220 ponticum.torproject.org ESMTP Postfix (Debian/GNU)
HELO ponticum.torproject.org
250 ponticum.torproject.org
MAIL FROM: isisgrimalkin at gmail.com
250 2.1.0 Ok
RCPT TO: bridges at bridges.torproject.org
250 2.1.5 Ok
DATA
354 End data with <CR><LF>.<CR><LF>
From: isislovecruft at gmail.com
To: givemebridgesrightnow at serious.ly
Subject: mwhahaha
get transport obfs3
.
250 2.0.0 Ok: queued as F03972834F
QUIT
221 2.0.0 Bye
This request resulted in the following debug logs:
_______________________________________________________________________________
15:30:31 DEBUG L690:server.validateFrom() ORIGIN: "'<bridgedb at ponticum>'"
15:30:31 DEBUG L699:server.validateFrom() Got canonical domain: 'ponticum'
15:30:31 DEBUG L495:server.lineReceived() > Received: from ponticum (ponticum [127.0.0.1]) for <bridges at bridgedb>; Wed, 21 May 2014 15:30:31 +0000
15:30:31 DEBUG L495:server.lineReceived() > From isisgrimalkin at gmail.com Wed May 21 15:30:31 2014
15:30:31 DEBUG L495:server.lineReceived() > X-Original-To: bridges at bridges.torproject.org
15:30:31 DEBUG L495:server.lineReceived() > Delivered-To: bridgedb at ponticum.torproject.org
15:30:31 DEBUG L495:server.lineReceived() > Received: from ponticum.torproject.org (kpebetka.net [95.79.25.182])
15:30:31 DEBUG L495:server.lineReceived() > by ponticum.torproject.org (Postfix) with SMTP id F03972834F
15:30:31 DEBUG L495:server.lineReceived() > for <bridges at bridges.torproject.org>; Wed, 21 May 2014 15:29:18 +0000 (UTC)
15:30:31 DEBUG L495:server.lineReceived() > From: isislovecruft at gmail.com
15:30:31 DEBUG L495:server.lineReceived() > To: givemebridgesrightnow at serious.ly
15:30:31 DEBUG L495:server.lineReceived() > Subject: mwhahaha
15:30:31 DEBUG L495:server.lineReceived() > X-DKIM-Authentication-Results: dunno
15:30:31 DEBUG L495:server.lineReceived() > Date: Wed, 21 May 2014 15:30:31 -0000
15:30:31 DEBUG L495:server.lineReceived() > Message-Id: <1400686231.135135.6548 at ponticum>
15:30:31 DEBUG L495:server.lineReceived() >
15:30:31 DEBUG L495:server.lineReceived() > get transport obfs3
15:30:31 DEBUG L495:server.lineReceived() >
15:30:31 INFO L611:server.reply() Got an email; deciding whether to reply.
15:30:31 INFO L646:server.reply() Client requested email translation: en
15:30:31 DEBUG L70:request.determineBridg() Email request was valid.
15:30:31 DEBUG L160:request.withPluggableT() Parsing 'transport' line: 'get transport obfs3'
15:30:31 INFO L169:request.withPluggableT() Email requested transport type: 'obfs3'
15:30:31 DEBUG L81:request.determineBridg() Generating hashring filters for request.
15:30:31 INFO L420:Dist.getBridgesForEmai() Attempting to return for 3 bridges for isislovecruft at gmail.com...
15:30:31 DEBUG L445:Dist.getBridgesForEmai() Cache hit frozenset([<function filterBridgesByTransport(obfs3,<class 'ipaddr.IPv4Address'>)>])
15:30:31 DEBUG L75:Dist.getNumBridgesPerA() Returning 3 bridges from ring of len: 492
15:30:31 DEBUG L1034:Bridges.getBridges() Got duplicate bridge 'edfa2fd66533da52f40424bbe917bd03c8378c2d' in main hashring for position 'eda7f69f7c08bd80861c3afa2921168a007d9ae5'.
15:30:31 DEBUG L1034:Bridges.getBridges() Got duplicate bridge 'ed0b2fd66f398afbf10424bb911790faca9ddb8e' in main hashring for position 'eda7f69f7c08bd80861c3afa2921168a007d9ae5'.
15:30:31 DEBUG L183:server.generateRespons() Email contents:
From: bridges at torproject.org
To: isislovecruft at gmail.com
Message-ID: <20140521153031.21456.73227139.10726 at ponticum.torproject.org>
In-Reply-To: <1400686231.135135.6548 at ponticum>
Content-Type: text/plain; charset="utf-8"
Date: Wed, 21 May 2014 15:30:31 +0000
Subject: Re: mwhahaha
Hey, isislovecruft!
[This is an automated message; please do not reply.]
Here are your bridges:
obfs3 10.1.1.1:1111 d14133856abbba8a65607baebf692162c567bf41
obfs3 10.2.2.2:2222 86f45ab5dcef80a4b1abfcc43579e76f1d0b25a4
obfs3 10.3.3.3:3333 5d55daabd91e041e74f62dcfab1a29c8bb32f0b2
To enter bridges into Tor Browser, follow the instructions on the Tor
Browser download page [0] to start Tor Browser.
When the 'Tor Network Settings' dialogue pops up, click 'Configure' and follow
the wizard until it asks:
> Does your Internet Service Provider (ISP) block or otherwise censor connections
> to the Tor network?
Select 'Yes' and then click 'Next'. To configure your new bridges, copy and
paste the bridge lines into the text input box. Finally, click 'Connect', and
you should be good to go! If you experience trouble, try clicking the 'Help'
button in the 'Tor Network Settings' wizard for further assistance.
[0]: https://www.torproject.org/projects/torbrowser.html.en#downloads-beta
COMMANDs: (combine COMMANDs to specify multiple options simultaneously)
get bridges Request vanilla bridges.
get transport [TYPE] Request a Pluggable Transport by TYPE.
get help Displays this message.
get key Get a copy of BridgeDB's public GnuPG key.
get ipv6 Request IPv6 bridges.
Currently supported transport TYPEs:
obfs2
obfs3
scramblesuit
--
<3 BridgeDB
----------------------------------------------------------------------
Public Keys: https://bridges.torproject.org/keys
This email was generated with rainbows, unicorns, and sparkles
for isislovecruft at gmail.com on Wednesday, 21 May, 2014 at 15:30:31.
15:30:31 INFO L655:server.reply() Sending reply to isislovecruft at gmail.com
_______________________________________________________________________________
Which obviously brings us to the other bug.
Bug #2:
-------
BridgeDB will accept an email from an arbitrary gmail/yahoo email
address at the SMTP layer, and then send the reply to a *different*
arbitrary gmail/yahoo email address taken from the contents of the email
headers.
As you can see in the example above, the SMTP command
'MAIL FROM: isisgrimalkin at gmail.com'
combined with a 'From: isislovecruft at gmail.com' in the email headers
within the SMTP DATA segment caused the reply to be sent the reply to
the later, when it came from the former. The person reading the response
from BridgeDB also has no way to know who originally emailed BridgeDB to
cause this email to end up in her inbox.
I'm not exactly certain if this is a bug or a feature. While it could be
used for sending some junk to an arbitrary gmail/yahoo address, it could
also be used as a sort of
"Dear BridgeDB, can I have some bridges? Asking for a friend."
mechanism.
Bug #2.5:
---------
Also, "dunno" certainly isn't a valid DKIM signature.
---
lib/bridgedb/test/test_email_server.py | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/lib/bridgedb/test/test_email_server.py b/lib/bridgedb/test/test_email_server.py
index d7f2922..32c40ac 100644
--- a/lib/bridgedb/test/test_email_server.py
+++ b/lib/bridgedb/test/test_email_server.py
@@ -323,6 +323,17 @@ class MailMessageTests(unittest.TestCase):
recipient = self.message.getRecipient(incoming)
self.assertEqual(recipient, self.context.fromAddr)
+ def test_MailMessage_getRecipient_givemebridges_at_seriously(self):
+ """MailMessage.getRecipient() for an incoming email sent to any email
+ address other than the one we're listening for should return our
+ configured address, not the one in the incoming email.
+ """
+ self._getIncomingLines()
+ self.message.lines[1] = 'To: givemebridges at serious.ly'
+ incoming = self.message.getIncomingMessage()
+ recipient = self.message.getRecipient(incoming)
+ self.assertEqual(recipient, self.context.fromAddr)
+
def test_MailMessage_getRecipient_bad_address(self):
"""MailMessage.getRecipient() for an incoming email sent to a malformed
email address should log an smtp.AddressError and then return our
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