[tor-bugs] #7419 [Tor]: Choose a faster memwipe implementation

Tor Bug Tracker & Wiki blackhole at torproject.org
Mon Mar 25 11:13:56 UTC 2013


#7419: Choose a faster memwipe implementation
-------------------------+--------------------------------------------------
 Reporter:  nickm        |          Owner:                  
     Type:  enhancement  |         Status:  new             
 Priority:  normal       |      Milestone:  Tor: unspecified
Component:  Tor          |        Version:                  
 Keywords:  tor-relay    |         Parent:                  
   Points:               |   Actualpoints:                  
-------------------------+--------------------------------------------------

Comment(by mo):

 hoppy on #nottor:

 so a while ago it was pointed out to me that I should not count on memset
 to zero sensitive memory because it could be optimized out, and was
 pointed to a Tor ticket (by NickM) that discussed this same thing in Tor
 and the solution suggested in that ticket was to use openssl cleanse
 instead
 but the ticket also pointed out that this was a heavy handed solution and
 there should be something better thought up and today I told this to
 somebody else who is developing a security program , to make sure to not
 use memset like I was in case they were, and to use openssl cleanse
 instead, and they said that a better solution is to use the word volatile
 in the cast because then the compiler doesn't optimize it out
 http://www.lix.polytechnique.fr/~liberti/public/computing/prog/c/C/SYNTAX/volatile.html
 so maybe that is better for Tor too , I dunno, just passing it on

-- 
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/7419#comment:3>
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