tree 28f41e31b8cd94e8ab6b15ef769586d86e1ca6f3
parent ac383701b77d9f82636c55e03ca7bad388c6ebf7
author David Benjamin <davidben@google.com> 1517097268 -0500
committer CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org> 1517886644 +0000

Make BN_cmp constant-time.

This is a bit easier to read than BN_less_than_consttime when we must do
>= or <=, about as much work to compute, and lots of code calls BN_cmp
on secret data. This also, by extension, makes BN_cmp_word
constant-time.

BN_equal_consttime is probably a little more efficient and is perfectly
readable, so leave that one around.

Change-Id: Id2e07fe312f01cb6fd10a1306dcbf6397990cf13
Reviewed-on: https://boringssl-review.googlesource.com/25444
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>