We upgraded a system from 4.4.2 to 4.4.3 last week. After that, the uac_auth() function didn't do what it was supposed to do anymore.

This is the failure route in the config file:

``` failure_route[TRUNKAUTH] { if (t_is_canceled()) { exit; }

if ($T_reply_code == 401 or $T_reply_code == 407) { xlog("L_NOTICE", "[$pr:$si:$sp] [$cs $rm cid: $ci Status: $rs $rr F:$fU T:$tU R:$rU] Remote asked for authentication"); uac_auth(); t_relay(); exit; } } ```

In Kamailio 4.4.2 this works perfectly. In 4.4.3 when this code triggers, we get the following messages in our log:

``` Sep 23 12:25:41 eustatius /usr/sbin/kamailio[13249]: NOTICE: <script>: [udp:1.2.3.4:5060] [102 INVITE cid: asdasdalsjdalsdaskjdlak Status: <null> <null> F:11111111 T:00491234567890 R:01234567890] Remote asked for authentication Sep 23 12:25:41 eustatius /usr/sbin/kamailio[13249]: ERROR: <core> [msg_translator.c:417]: clen_builder(): no message body found (missing crlf?) Sep 23 12:25:41 eustatius /usr/sbin/kamailio[13249]: ERROR: <core> [msg_translator.c:1963]: build_req_buf_from_sip_req(): Error while adjusting Content-Length Sep 23 12:25:41 eustatius /usr/sbin/kamailio[13249]: ERROR: tm [t_fwd.c:462]: prepare_new_uac(): could not build request Sep 23 12:25:41 eustatius /usr/sbin/kamailio[13249]: ERROR: tm [t_fwd.c:1723]: t_forward_nonack(): ERROR: t_forward_nonack: failure to add branches Sep 23 12:25:41 eustatius /usr/sbin/kamailio[13249]: ERROR: tm [tm.c:1415]: _w_t_relay_to(): ERROR: w_t_relay_to: t_relay_to failed ```

After downgrading to 4.4.2, everything works again.