tls_peer_cert_chain_pem
const uint8_t *tls_peer_cert_chain_pem(struct tls *_ctx, size_t *_len);
if ((pem = tls_peer_cert_chain_pem(tls_ctx, &plen)) == NULL)
servercert = tls_peer_cert_chain_pem(con->se_out.tls,