server: add SSL_OP_NO_RENEGOTIATION fallback path
This MR is the second attempt at !208 (closed).
With LibreSSL SSL_OP_NO_CLIENT_RENEGOTIATION
is opaque which is not compatible with the OpenSSL 1.0.2 and earlier code path in red-stream.cpp
while SSL_OP_NO_RENEGOTIATION
is not yet defined for the newer OpenSSL code path in reds.cpp
.
So with OpenSSL 1.1.0 and later if SSL_OP_NO_RENEGOTIATION
is undefined and SSL_OP_NO_CLIENT_RENEGOTIATION
is defined then define the former as the latter. This will allow the build to succeed with LibreSSL 3.7.2 and in the future when newer LibreSSL versions add SSL_OP_NO_RENEGOTIATION
that code path will then be used automatically.