SSL_VERIFY_POST_HANDSHAKE
SSL_VERIFY_PEER | SSL_VERIFY_POST_HANDSHAKE),
SSL_VERIFY_PEER | SSL_VERIFY_POST_HANDSHAKE | SSL_VERIFY_FAIL_IF_NO_PEER_CERT),
|| !(s->verify_mode & SSL_VERIFY_POST_HANDSHAKE)
SSL_set_verify(serverssl, SSL_VERIFY_PEER | SSL_VERIFY_FAIL_IF_NO_PEER_CERT | SSL_VERIFY_POST_HANDSHAKE, rpk_verify_server_cb);