[tor-bugs] #9380 [BridgeDB]: BridgeDB should use Stem for parsing descriptors

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#9380: BridgeDB should use Stem for parsing descriptors
-------------------------+-------------------------------------------------
     Reporter:  sysrqb   |      Owner:  isis
         Type:           |     Status:  needs_review
  enhancement            |  Milestone:
     Priority:  blocker  |    Version:
    Component:           |   Keywords:  stem, bridgedb-0.3.0, bridgedb-
  BridgeDB               |  parsers, isis2014Q3Q4, isisExB
   Resolution:           |  Parent ID:
Actual Points:           |
       Points:           |
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Comment (by isis):

 FWIW, from #2895:

 BridgeDB's verification chain for descriptors currently (as of #9380) goes
 like this:

  1.
 [https://gitweb.torproject.org/user/isis/bridgedb.git/tree/lib/bridgedb/parse/descriptors.py?h=fix/9380-stem_r10#n70
 Parse] the `@type bridge-networkstatus` documents in the `networkstatus-
 bridges` file.

  2. Create `Bridge`
 [https://gitweb.torproject.org/user/isis/bridgedb.git/tree/lib/bridgedb/bridges.py?h=fix/9380-stem_r10#n735
 class] instances for each this we parsed in step !#1. Call the
 `Bridge.updateFromNetworkStatus()`
 [https://gitweb.torproject.org/user/isis/bridgedb.git/tree/lib/bridgedb/bridges.py?h=fix/9380-stem_r10#n1338
 method] with the corresponding networkstatus document for each Bridge.
 This includes storing the
 [https://gitweb.torproject.org/user/isis/bridgedb.git/tree/lib/bridgedb/bridges.py?h=fix/9380-stem_r10#n1348
 descriptor digest] for each Bridge.

  3.
 [https://gitweb.torproject.org/user/isis/bridgedb.git/tree/lib/bridgedb/parse/descriptors.py?h=fix/9380-stem_r10#n123
 Parse] the `@type bridge-server-descriptor`s found in the `bridge-
 descriptors` file.

  4.
 [https://gitweb.torproject.org/user/isis/bridgedb.git/tree/lib/bridgedb/bridges.py?h=fix/9380-stem_r10#n1363
 Update] each Bridge
 [https://gitweb.torproject.org/user/isis/bridgedb.git/tree/lib/bridgedb/bridges.py?h=fix/9380-stem_r10#n881
 only if the descriptor digest matches] the digested value of the `@type
 bridge-server-descriptor` that was just parsed.

  5.
 [https://gitweb.torproject.org/user/isis/bridgedb.git/tree/lib/bridgedb/bridges.py?h=fix/9380-stem_r10#n1411
 Store] the `extra-info-digest` from each `@type bridge-server-descriptor`.

  6.
 [https://gitweb.torproject.org/user/isis/bridgedb.git/tree/lib/bridgedb/parse/descriptors.py?h=fix/9380-stem_r10#n219
 Parse] and
 [https://gitweb.torproject.org/user/isis/bridgedb.git/tree/lib/bridgedb/parse/descriptors.py?h=fix/9380-stem_r10#n149
 deduplicate] the `@type bridge-extrainfo` descriptors in `cached-
 extrainfo` and `cached-extrainfo.new`.

  7.
 [https://gitweb.torproject.org/user/isis/bridgedb.git/tree/lib/bridgedb/bridges.py?h=fix/9380-stem_r10#n1413
 Verify] the `router-signature` on the `@type bridge-extrainfo` descriptor
 for each bridge, using the `signing-key` from the Bridge's `@type bridge-
 server-descriptor`.

  8.
 [https://gitweb.torproject.org/user/isis/bridgedb.git/tree/lib/bridgedb/bridges.py?h=fix/9380-stem_r10#n1497
 Update] the Bridge's
 [https://gitweb.torproject.org/user/isis/bridgedb.git/tree/lib/bridgedb/bridges.py?h=fix/9380-stem_r10#n203
 PluggableTransport class] instances.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/9380#comment:39>
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