[HTTPS-Everywhere] Startup time measurements in Chrome and Firefox

[Peter Eckersley]

On Fri, Jan 17, 2014 at 06:37:02PM -0800, Mike Perry wrote:
 
> So this would be exposing a global fingerprinting vector that didn't
> previously exist in TBB. OTOH, it would probably only be possible for
> the adversary to examine it once before it becomes useless to anyone
> else.. But once may be enough.
> 
> How fast are these individual queries? Can we measure that, and what the
> impact is on total page performance for the cache hit and non-cache hit
> cases?

We should measure this.  But we should definitely measure it in the case
where the entire sqlite file is in the OS page cache, so in TBB we
should /definitely/ read and discard its entire contents before playing.
 
> Do we know how big the actual memory consumption is here? Right now, the
> plaintext xml rulesets are 3.6M on disk. I suspect once parsed they are
> smaller than that, but I am not seeing any easy way to get the memory
> usage for the actual parsed rulesets object. It seems the most common
> solution on the web is to manually traverse the thing and do some
> addition and approximation for each object type. :/

Unfortunately I fear they're actually larger because of all the pointers
and JavaScript book-keeping.  I've tried to measure that by just looking
at the RSS of the firefox process with and without HTTPSE enabled:

https://trac.torproject.org/projects/tor/ticket/4804

-- 
Peter Eckersley                            pde at eff.org
Technology Projects Director      Tel  +1 415 436 9333 x131
Electronic Frontier Foundation    Fax  +1 415 436 9993