tls_cbc.c is concerned with the variation in where the padding+mac may
end, counted in blocks. Hash blocks are larger than block cipher blocks,
and the hash itself appends some padding. Thus maximal padding off a
64-hash.Size() bytes may not fully stress things.
Just run all inputs modulo the hash block size, so we don't have to
think very hard about the "most difficult" input.
Change-Id: I8da1427dfff855931c14a9135c22afbff4f367c0
Reviewed-on: https://boringssl-review.googlesource.com/c/32724
Commit-Queue: Adam Langley <agl@google.com>
Reviewed-by: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
