[tor-bugs] #11611 [Obfsproxy]: obfs2/obfs3 AES counter initialization is incorrect.

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#11611: obfs2/obfs3 AES counter initialization is incorrect.
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     Reporter:  yawning    |      Owner:  asn
         Type:  defect     |     Status:  new
     Priority:  normal     |  Milestone:
    Component:  Obfsproxy  |    Version:
   Resolution:             |   Keywords:
Actual Points:             |  Parent ID:
       Points:             |
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Comment (by asn):

 Hm, thanks for catching this.

 PyCrypto increments the counter by one for each use, right? If yes, I
 don't see a big problem with switching `allow_wraparound` to `True`.

 OTOH, maybe for other protocols, where the IV is not derived from the
 protocol, the current behavior of bailing on wraparound is more sane.

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Ticket URL: <https://trac.torproject.org:443/projects/tor/ticket/11611#comment:1>
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