SSL_CTX_set_npn_advertised_cb
SSL_CTX_set_npn_advertised_cb(server_ctx, server_npn_cb,
SSL_CTX_set_npn_advertised_cb(server2_ctx, server_npn_cb,
SSL_CTX_set_npn_advertised_cb(s_ctx, cb_server_npn, NULL);
SSL_CTX_set_npn_advertised_cb(s_ctx2, cb_server_npn, NULL);
SSL_CTX_set_npn_advertised_cb(s_ctx, cb_server_rejects_npn, NULL);
SSL_CTX_set_npn_advertised_cb(s_ctx2, cb_server_rejects_npn, NULL);