LibreSSL doesn't support the SSL_OP_NO_RENEGOTIATION macro which is
used by OpenSSL, instead it has invented a similar one for client-
side renegotiation: SSL_OP_NO_CLIENT_RENEGOTIATION. This has been
supported since LibreSSL 2.5.1 which by now can be considered well
below the minimum requirement.
Reviewed-by: Peter Eisentraut <peter@eisentraut.org>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/eac70d46-e61c-4d71-a1e1-78e2bfa19485@eisentraut.org