See also 8129ac6ac4c0ca3a488c225cde580ede7dabe874 and
81198bf323ea9deda907714170d329ca7d2ff01f from upstream.
In trying to figure out why ASan (which normally catches overlapping
memcpys) didn't flag this, I noticed that we actually don't have tests
for empty inputs. I've added them to cipher_tests.txt where missing and
fixed a bad assert in ofb.c.
ASan still doesn't flag this because LLVM even requires memcpy handle
dst == src. Still, fixing it is less effort than getting a clear answer
from GCC and MSVC. Though this puts us in the frustrating position of
trying to follow a C rule that our main toolchain and sanitizer disavow.
https://bugs.llvm.org/show_bug.cgi?id=11763https://reviews.llvm.org/D86993
Change-Id: I53c64a84834ddf5cddca0b3d53a29998f666ea2f
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/46285
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
David Benjamin