post-review fixes:
* move all ssl implementation related ifdefs/defines to one file
(ssl_compat.h)
* work around OpenSSL-1.1 desire to malloc every EVP context by
run-time checking that context allocated on the stack is big enough
(openssl.c)
* use newer version of the AWS SDK for OpenSSL 1.1
* use get_dh2048() function as generated by openssl 1.1
(viosslfactories.c)
Initial support
tested against OpenSSL 1.0.1, 1.0.2, 1.1.0, Yassl and LibreSSL
not working on Windows with native SChannel support, due to wrong cipher
mapping: Latter one requires push of CONC-241 fixes.
Please note that OpenSSL 0.9.8 and OpenSSL 1.1.0 will not work: Even if
the build succeeds, test cases will fail with various errors, especially
when using different tls libraries or versions for client and server.
Tell OpenSSL to use MD5 even if FIPS prohibits it.
This is fine as long as we do not use MD5 for cryptographical
purposes (md5 is used internally for P_S message digests and for view
checksums)
When wsrep is enabled, an md5 hash of the entire row is calculated
for tables with no PK. It, however segfaulted as the md5 context
object was not properly constructed.
Fixed by ensuring that the YaSSL's context object gets constructed
explicitly at the specified pre-allocated location (placement)
before its used.
Added a test case.
