- introduce lib/tls/mbedtls lib/tls/openssl
- move wrapper into lib/tls/mbedtls/wrapper
- introduce private helpers to hide backend
This patch doesn't replace or remove the wrapper, it moves it
to lib/tls/mbedtls/wrapper.
But it should be now that the ONLY functions directly consuming
wrapper apis are isolated in
- lib/tls/mbedtls/client.c (180 lines)
- lib/tls/mbedtls/server.c (317 lines)
- lib/tls/mbedtls/ssl.c (325 lines)
In particular there are no uses of openssl or mbedtls-related
constants outside of ./lib/tls any more.
The mbedTLS / OpenSSL wrapper spins for the duration of the
handshake, which is a slow 31ms on my x86_64 box (by comparison
it's ~1ms on actual OpenSSL on the same box).
This doesn't change the 31ms but it stops us spinning during the
accept and has us retry on POLLIN instead like OpenSSL.
Note this also fixes the endemic mismatches in returncode
between mbedTLS and OpenSSL semantics...
This adds the necessary OpenSSL Apis to the mbedTLS openssl wrapper
to allow ALPN negotiation OpenSSL-style.
The OpenSSL upgrade list format is supported and converted to mbedtls
format at runtime.
