RISCs are picky and alignment granted by compiler for md_state can be
insufficient for SHA512.
(cherry picked from commit 36260233e7e3396feed884d3f501283e0453c04f)
Break dependency on uint64_t. It's possible to declare bits as
unsigned int, because TLS packets are limited in size and 32-bit
value can't overflow.
(cherry picked from commit cab13fc8473856a43556d41d8dac5605f4ba1f91)
We have to use EVP in FIPS mode so we can only partially mitigate
timing differences.
Make an extra call to HMAC_Update to hash additonal blocks
to cover any timing differences caused by removal of padding.
