tree c12e64871091630e5d807098e18623a13af65705
parent a3123910509c5ae5f8b8475bdeed1944a5a42fab
author Adam Langley <alangley@gmail.com> 1517772014 -0800
committer CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org> 1517796209 +0000

Set output point to the generator when not on the curve.

Processing off-curve points is sufficiently dangerous to worry about
code that doesn't check the return value of
|EC_POINT_set_affine_coordinates| and |EC_POINT_oct2point|. While we
have integrated on-curve checks into these functions, code that ignores
the return value will still be able to work with an invalid point
because it's already been installed in the output by the time the check
is done.

Instead, in the event of an off-curve point, set the output point to the
generator, which is certainly on the curve and hopefully safe.

Change-Id: Ibc73dceb2d8d21920e07c4f6def2c8249cb78ca0
Reviewed-on: https://boringssl-review.googlesource.com/25724
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>