[tor-bugs] #11257 [Stem]: Stem believes that all bridge-extrainfo-descriptors have a 'router-digest' field

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#11257: Stem believes that all bridge-extrainfo-descriptors have a 'router-digest'
field
------------------------------+------------------------
 Reporter:  isis              |          Owner:  atagar
     Type:  defect            |         Status:  new
 Priority:  normal            |      Milestone:
Component:  Stem              |        Version:
 Keywords:  bridgedb-parsers  |  Actual Points:
Parent ID:                    |         Points:
------------------------------+------------------------
 When parsing the following mock descriptor, which looks identical to a
 current real `@type bridge-extrainfo` descriptor, I get the following
 exception:

 {{{
 In [1]: import stem

 In [2]: stem.__version__
 Out[2]: '1.1.1'

 In [3]: from stem.descriptor import extrainfo_descriptor

 In [4]: raweidesc = """
 extra-info LoneRevulsion E72E3DC5FAD5550DBCCB4429BBF0A7BB2FAD72E2
 published 2014-03-12 20:56:50
 write-history 2014-03-12 20:56:50 (900 s) 3188736,2226176,2866176
 read-history 2014-03-12 20:56:50 (900 s) 3891200,2483200,2698240
 dirreq-write-history 2014-03-12 20:56:50 (900 s) 1024,0,2048
 dirreq-read-history 2014-03-12 20:56:50 (900 s) 0,0,0
 geoip-db-digest D7D3AB5AF68AAC8F316BF9DEE7B7D0B0BC1238D7
 geoip6-db-digest 76634AB48969832AA37F78F252726AB9803ECFB8
 dirreq-stats-end 2014-03-12 20:56:50 (86400 s)
 dirreq-v3-ips
 dirreq-v3-reqs
 dirreq-v3-resp ok=16,not-enough-sigs=0,unavailable=0,not-found=0,not-
 modified=0,busy=0
 dirreq-v3-direct-dl complete=0,timeout=0,running=0
 dirreq-v3-tunneled-dl complete=12,timeout=0,running=0
 transport obfs3 254.99.16.232:31196
 transport obfs2 254.99.16.232:31197
 bridge-stats-end 2014-03-12 20:56:50 (86400 s)
 bridge-ips ca=8
 bridge-ip-versions v4=8,v6=0
 bridge-ip-transports <OR>=8
 router-signature
 -----BEGIN SIGNATURE-----
 duS1H+K32B3uKYA2sKcl+cKXL8PXKfJAQ+gnmsQ949qM85/8fWeX1j9xyUAlpN8q
 5lUm0gSoNRLraTTtVg6jYA9BTlfcMlYz6hoyKjQRbFeT8OiU0Z3alQFCZl/qlVii
 0juw8yjc6p4gNprm7gfP+h2VImm27kC/ZMNvloB5bEs=
 -----END SIGNATURE-----
 """

 In [5]: extrainfo_descriptor.BridgeExtraInfoDescriptor(raweidesc)
 ---------------------------------------------------------------------------
 ValueError                                Traceback (most recent call
 last)
 <ipython-input-3-0ed04607c709> in <module>()
 ----> 1 extrainfo_descriptor.BridgeExtraInfoDescriptor(raweidesc)

 /home/isis/.virtualenvs/bridgedb/lib/python2.7/site-
 packages/stem/descriptor/extrainfo_descriptor.pyc in __init__(self,
 raw_contents, validate)
     904     self._digest = None
     905
 --> 906     super(BridgeExtraInfoDescriptor, self).__init__(raw_contents,
 validate)
     907
     908   def digest(self):

 /home/isis/.virtualenvs/bridgedb/lib/python2.7/site-
 packages/stem/descriptor/extrainfo_descriptor.pyc in __init__(self,
 raw_contents, validate)
     423       for keyword in self._required_fields():
     424         if not keyword in entries:
 --> 425           raise ValueError("Extra-info descriptor must have a '%s'
 entry" % keyword)
     426
     427       for keyword in self._required_fields() + SINGLE_FIELDS:

 ValueError: Extra-info descriptor must have a 'router-digest' entry
 }}}

 Atagar says this was done
 [https://gitweb.torproject.org/stem.git/commitdiff/e7e03d2f61d6dcc7bc5e5ad4dee91c37a814ee16
 in this commit], because the sanitised bridge descriptors on the metrics
 server are supposed to have the 'router-digest' field, which is a SHA-1 of
 the corresponding `@type bridge-server-descriptor`.

 BridgeDB needs an extrainfo parser which works with ''unsanitised''
 descriptors (see #9380, #10725, and #11216). We probably need to create an
 `UnsanitisedBridgeExtraInfoDescriptor` class in Stem, if atagar is will to
 take such a patch. :) If not, I can keep the `Unsanitised` classes in
 BridgeDB, since presently that is the only component which would actually
 be using these classes. (I can also maintain them, if they end up in Stem,
 since I'll likely be one of the only people to notice if something
 breaks/changes.)

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/11257>
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