data_plus_mac_size is secret. Values derived from it cannot quite be
safely divided by md_block_size because SHA-384 ciphers prevent that
field from being constant. We know the value is a power of two, so do
the strength reduction by hand.
Change-Id: Id62ab9e646f4e21d507a7059cfe84d49bbb986e6
Reviewed-on: https://boringssl-review.googlesource.com/27505
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
024f5df3c8