SSL_CTX_set1_param
SSL_CTX_set1_param(ctx, s_client_config.vpm);
SSL_CTX_set1_param(ctx, s_server_config.vpm);
SSL_CTX_set1_param(ctx2, s_server_config.vpm);
int SSL_CTX_set1_param(SSL_CTX *ctx, X509_VERIFY_PARAM *vpm);