[tor-bugs] #9499 [BridgeDB]: BridgeDB should hand out identity fingerprints

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#9499: BridgeDB should hand out identity fingerprints
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 Reporter:  mikeperry  |          Owner:     
     Type:  defect     |         Status:  new
 Priority:  normal     |      Milestone:     
Component:  BridgeDB   |        Version:     
 Keywords:  path-bias  |         Parent:     
   Points:             |   Actualpoints:     
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 Once we deprecate Vidalia fully and switch to Tor Launcher, nothing should
 be in the way of handing out identity hex keys for bridges. Well, nothing
 except #9445 (which if it comes down to it, I can fix quickly myself).

 It is important to hand out these fingerprints because it mitigates path
 bias/route capture attacks. Without the identity fingerprint, a firewall
 could potentially MITM the bridge connection for purposes of unwrapping
 TLS, in order to see the Tor cell headers and bitstomp/tag cells to
 control circuit destinations and deanonymize users. We have detectors for
 these attacks in place, but they can't be enforced yet because of the
 highly variable rate of CPU overload/circuit failure on the network. Other
 solutions to bitstomping (like wide-block ciphers) will also mitigate
 these attacks, but they are a long ways off.

 With the identity fingerprint, the TLS links will be authenticated (our
 TLS connections use the identity key to sign a short-lived TLS link key).

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/9499>
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