We still have our <= 0 return values because anything with BIOs tries to
preserve BIO_write's error returns. (Maybe we can stop doing this?
BIO_read's error return is a little subtle with EOF vs error, but
BIO_write's is uninteresting.) But the rest of the logic is size_t-clean
and hopefully a little clearer. We still have to support SSL_write's
rather goofy calling convention, however.
I haven't pushed Spans down into the low-level record construction logic
yet. We should probably do that, but there are enough offsets tossed
around there that they warrant their own CL.
Bug: 507
Change-Id: Ia0c702d1a2d3713e71b0bbfa8d65649d3b20da9b
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/47544
Commit-Queue: Bob Beck <bbe@google.com>
Reviewed-by: Bob Beck <bbe@google.com>