[tor-bugs] #2927 [Tor Relay]: Tor doesn't overwrite rotated keys

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#2927: Tor doesn't overwrite rotated keys
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 Reporter:  asn        |          Owner:     
     Type:  defect     |         Status:  new
 Priority:  normal     |      Milestone:     
Component:  Tor Relay  |        Version:     
 Keywords:             |         Parent:     
   Points:             |   Actualpoints:     
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 Tor doesn't zero out rotated onion keys, or rotated x509s and currently
 leaves them into memory for anyone to have fun with them.

 The fact that Tor uses PFS TLS ciphersuites saves the day, but still
 sensitive stuff should be overwritten to be on the safe side.

 Onion keys should get memsetted somewhere around the
 crypto_free_pk_env(lastonionkey);
 of rotate_onion_key()

 and TLS certificates should get memsetted in:
 tor_tls_context_decref().

 OpenSSL has functions that clean keys correctly, iirc.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/2927>
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