tor/changes/bug6538
Nick Mathewson 640a51684c Remove remaining timing-dependency in choosing nodes by bandwidth
The old approach, because of its "tmp >= rand_bw &&
!i_has_been_chosen" check, would run through the second part of the
loop slightly slower than the first part.  Now, we remove
i_has_been_chosen, and instead set rand_bw = UINT64_MAX, so that
every instance of the loop will do exactly the same amount of work
regardless of the initial value of rand_bw.

Fix for bug 6538.
2012-08-09 12:40:03 -04:00

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o Minor bugfixes:
- Switch weighted node selection rule from using a list of doubles
to using a list of int64_t. This should make the process slightly
easier to debug and maintain. Needed for fix for bug 6538.
o Security features:
- Switch to a completely time-invariant approach for picking nodes
weighted by bandwidth. Our old approach would run through the
part of the loop after it had made its choice slightly slower
than it ran through the part of the loop before it had made its
choice. Fix for bug 6538.