gistfile1.c

if (s->servername_done == 0) {
    switch (servname_type) {
        case TLSEXT_NAMETYPE_host_name:
            if (s->session->tlsext_hostname == NULL) {
                if (len > TLSEXT_MAXLEN_host_name ||
                    ((s->session->tlsext_hostname = OPENSSL_malloc(len + 1)) == NULL)) {
                    *al = TLS1_AD_UNRECOGNIZED_NAME;
                    return 0;
                }
                memcpy(s->session->tlsext_hostname, sdata, len);
                s->session->tlsext_hostname[len] = '\0';
            }
    }
}