SSL_SESSION_get_id
SSL_SESSION_get_id(session, &sess->idlen);
sess->id = OPENSSL_memdup(SSL_SESSION_get_id(session, NULL), sess->idlen);
id = SSL_SESSION_get_id(session, &idlen);
const unsigned char *SSL_SESSION_get_id(const SSL_SESSION *s,
SSL_SESSION_get_id(serv_sess_in, &sess_id_len);
sess_id = SSL_SESSION_get_id(sess, &sess_id_len);
sessid = SSL_SESSION_get_id(server_sess, &sess_len);