https://boringssl-review.googlesource.com/c/boringssl/+/41084
inadvertently added a somewhat expensive operation (field inversion) in
the path of EC_POINT_point2oct when passed with buf == NULL. The result
is a caller that calls the function twice, first to measure and then to
serialize, actually ends up doing the field inversion twice.
Fix this by removing the dual-use calling convention from the internal
function and just have a separate function to measure the output size
separately. It's slightly subtle because EC_POINT_point2oct would check
for the point at infinity by way of converting to affine coordinates, so
we do need to repeat that check.
As part of this, add a unit test for
https://boringssl-review.googlesource.com/6488, which rejected the point
at infinity way back.
Change-Id: I3b6c0f95cced9c00489386f064a2c3f0bb1776f8
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/55065
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Certain applications of Trust Token need to be able to generate
a large number of keys, instead of storing them all, we provide
an API to take a secret that can be used to generate keys
in a deterministic manner.
Change-Id: I2b61958d1e949a3a47a3c91ab3a866c2e33a9d1d
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/53011
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: Steven Valdez <svaldez@google.com>