<div dir="ltr">Hi All,<div><br></div><div>Further to this issue I have established that the fault occurs when the server does not provide a finish "Encrypted Handshake Message" following key/cert exchange.</div><div><br></div><div>Based on my test patterns it seems to indicate that this improves <i>slightly</i> over time meaning that its gets a bit more reliable after a few calls have been processed by the remote. This doesn't mean that the calls don't ever fail though, it goes from 50% failure rate to 20% perhaps.</div><div><br></div><div>Does anyone have confidence that this indicates a fault with the remote system rather than the OpenSIPs implementation? </div><div><br></div><div>Thanks</div></div><br><div class="gmail_quote"><div dir="ltr">On Mon, Jun 18, 2018 at 1:15 PM Callum Guy <<a href="mailto:callum.guy@x-on.co.uk">callum.guy@x-on.co.uk</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><span style="color:rgb(33,33,33);font-size:13px">Hi All,</span><div style="color:rgb(33,33,33);font-size:13px"><br></div><div style="color:rgb(33,33,33);font-size:13px">I'm running a TLS protected service using OpenSIPs 2.3.3 and openssl-1.0.2k-12.el7.x86_64 on a CentOS 7.5 server. RTPProxy is in place to forward all the media on every call.</div><div style="color:rgb(33,33,33);font-size:13px"><br></div><div style="color:rgb(33,33,33);font-size:13px">OpenSIPs is acting as a proxy to an internal FreeSWITCH instance and handling all inbound and outbound TLS negotiation. </div><div style="color:rgb(33,33,33);font-size:13px"><br></div><div style="color:rgb(33,33,33);font-size:13px">The call scenario is:</div><div style="color:rgb(33,33,33);font-size:13px">Leg A: carrier -> opensips -> freeswitch (answer)</div><div style="color:rgb(33,33,33);font-size:13px">Leg B: freeswitch -> opensips ->carrier</div><div style="color:rgb(33,33,33);font-size:13px"><br></div><div style="color:rgb(33,33,33);font-size:13px">I have a situation where calls sometimes fail during TLS negotiation on the B leg. The exact same call will work only seconds before and then the subsequent call will fail. This is still a test service so there is no traffic on the platform which would effect the calls.</div><div style="color:rgb(33,33,33);font-size:13px"><br></div><div style="color:rgb(33,33,33);font-size:13px">The destination carrier is Twilio where we are targeting a custom domain which provides three separate fallback IP's. The logs (below) show each being attempted in sequence and OpenSIPs is reporting failure.</div><div style="color:rgb(33,33,33);font-size:13px"><br></div><div style="color:rgb(33,33,33);font-size:13px">I have a packet capture (SIP encrypted) which shows that the carrier (Twilio) are setting up the connection and attempting to change the cipher spec, from my understanding it looks like this is what triggers the errors in OpenSIPs which then returns a SIP packet to Twilio before trying the next IP in the list (see screen shot below).</div><div style="color:rgb(33,33,33);font-size:13px"><br></div><div style="color:rgb(33,33,33);font-size:13px">When viewing the packet capture on a call which was not affected I don't see wireshark reporting "Change Cipher Spec" from the carrier network so at present this is the main suspicion. Unfortunately this is as far as my current understanding can take me so while i continue to research i wanted to reach out to see is anyone in the community can help! Let me know if I can provide any further information.</div><div style="color:rgb(33,33,33);font-size:13px"><br></div><div style="color:rgb(33,33,33);font-size:13px">Thanks! </div><div style="color:rgb(33,33,33);font-size:13px"><br></div><div style="color:rgb(33,33,33);font-size:13px"><b>OpenSIPs Log</b></div><div style="color:rgb(33,33,33);font-size:13px"><br></div><div style="color:rgb(33,33,33);font-size:13px"><div>Jun 18 11:20:33 opensips[6373]: INFO: [INVITE] (outbound) REST response: RU: sip:<a href="tel:+353%2061%20234%20567" value="+35361234567" target="_blank">+35361234567</a>@custom.pstn.ie1.twilio.com:5061;transport=tls DU: sip:<a href="http://custom.pstn.ie1.twilio.com:5061/" target="_blank">custom.pstn.ie1.twilio.com:5061</a> FU: "<a href="tel:+49%2040%20261234567" value="+4940261234567" target="_blank">+4940261234567</a>" <si</div><div><a href="mailto:ps%3A%2B4940261234567@172.20.0.101" target="_blank">ps:+4940261234567@172.20.0.101</a>> To(sip:35361234567@172.18.0.110:5061;transport=tls) From(<a href="mailto:sip%3A%2B40261234567@172.20.0.101" target="_blank">sip:+40261234567@172.20.0.101</a>) ID:137a5be9-ed84-1236-10aa-d0431e9b59cf</div><div>Jun 18 11:20:33 opensips[6373]: INFO:core:probe_max_sock_buff: using snd buffer of 416 kb</div><div>Jun 18 11:20:33 opensips[6373]: INFO:core:init_sock_keepalive: TCP keepalive enabled on socket 29</div><div>Jun 18 11:20:33 opensips[6373]: NOTICE:tls_mgm:verify_callback: depth = 2</div><div>Jun 18 11:20:33 opensips[6373]: NOTICE:tls_mgm:verify_callback: preverify is good: verify return: 1</div><div>Jun 18 11:20:33 opensips[6373]: NOTICE:tls_mgm:verify_callback: depth = 1</div><div>Jun 18 11:20:33 opensips[6373]: NOTICE:tls_mgm:verify_callback: preverify is good: verify return: 1</div><div>Jun 18 11:20:33 opensips[6373]: NOTICE:tls_mgm:verify_callback: depth = 0</div><div>Jun 18 11:20:33 opensips[6373]: NOTICE:tls_mgm:verify_callback: preverify is good: verify return: 1</div><div><b>Jun 18 11:20:34 opensips[6373]: ERROR:proto_tls:tls_blocking_write: TLS send timeout (60)</b></div><div><b>Jun 18 11:20:34 opensips[6373]: ERROR:proto_tls:proto_tls_send: failed to send</b></div><div><b>Jun 18 11:20:34 opensips[6373]: ERROR:tm:msg_send: send() to <a href="http://54.171.127.194:5061/" target="_blank">54.171.127.194:5061</a> for proto tls/3 failed</b></div><div><b>Jun 18 11:20:34 opensips[6373]: ERROR:tm:t_forward_nonack: sending request failed</b></div><div>Jun 18 11:20:34 opensips[6373]: INFO:core:probe_max_sock_buff: using snd buffer of 416 kb</div><div>Jun 18 11:20:34 opensips[6373]: INFO:core:init_sock_keepalive: TCP keepalive enabled on socket 29</div><div>Jun 18 11:20:34 opensips[6373]: NOTICE:tls_mgm:verify_callback: depth = 2</div><div>Jun 18 11:20:34 opensips[6373]: NOTICE:tls_mgm:verify_callback: preverify is good: verify return: 1</div><div>Jun 18 11:20:34 opensips[6373]: NOTICE:tls_mgm:verify_callback: depth = 1</div><div>Jun 18 11:20:34 opensips[6373]: NOTICE:tls_mgm:verify_callback: preverify is good: verify return: 1</div><div>Jun 18 11:20:34 opensips[6373]: NOTICE:tls_mgm:verify_callback: depth = 0</div><div>Jun 18 11:20:34 opensips[6373]: NOTICE:tls_mgm:verify_callback: preverify is good: verify return: 1</div><div><b>Jun 18 11:20:34 opensips[6373]: ERROR:proto_tls:tls_blocking_write: TLS send timeout (60)</b></div><div><b>Jun 18 11:20:34 opensips[6373]: ERROR:proto_tls:proto_tls_send: failed to send</b></div><div><b>Jun 18 11:20:34 opensips[6373]: ERROR:tm:msg_send: send() to <a href="http://54.171.127.193:5061/" target="_blank">54.171.127.193:5061</a> for proto tls/3 failed</b></div><div><b>Jun 18 11:20:34 opensips[6373]: ERROR:tm:t_forward_nonack: sending request failed</b></div><div>Jun 18 11:20:34 opensips[6373]: INFO:core:probe_max_sock_buff: using snd buffer of 416 kb</div><div>Jun 18 11:20:34 opensips[6373]: INFO:core:init_sock_keepalive: TCP keepalive enabled on socket 29</div><div>Jun 18 11:20:34 opensips[6373]: NOTICE:tls_mgm:verify_callback: depth = 2</div><div>Jun 18 11:20:34 opensips[6373]: NOTICE:tls_mgm:verify_callback: preverify is good: verify return: 1</div><div>Jun 18 11:20:34 opensips[6373]: NOTICE:tls_mgm:verify_callback: depth = 1</div><div>Jun 18 11:20:34 opensips[6373]: NOTICE:tls_mgm:verify_callback: preverify is good: verify return: 1</div><div>Jun 18 11:20:34 opensips[6373]: NOTICE:tls_mgm:verify_callback: depth = 0</div><div>Jun 18 11:20:34 opensips[6373]: NOTICE:tls_mgm:verify_callback: preverify is good: verify return: 1</div><div><b>Jun 18 11:20:34 opensips[6373]: ERROR:proto_tls:tls_blocking_write: TLS send timeout (60)</b></div><div><b>Jun 18 11:20:34 opensips[6373]: ERROR:proto_tls:proto_tls_send: failed to send</b></div><div><b>Jun 18 11:20:34 opensips[6373]: ERROR:tm:msg_send: send() to <a href="http://54.171.127.192:5061/" target="_blank">54.171.127.192:5061</a> for proto tls/3 failed</b></div><div><b>Jun 18 11:20:34 opensips[6373]: ERROR:tm:t_forward_nonack: sending request failed</b></div><div><b>Jun 18 11:20:34 opensips[6373]: ERROR:tm:w_t_relay: t_forward_nonack failed</b></div><div><b>Jun 18 11:20:34 opensips[6373]: ERROR: Failed to relay call - DU:<null> [INVITE] To(sip:35361234567@172.18.0.110:5061;transport=tls) From(<a href="mailto:sip%3A%2B40261234567@172.20.0.101" target="_blank">sip:+40261234567@172.20.0.101</a>) ID:137a5be9-ed84-1236-10aa-d0431e9b59</b></div></div><div><br></div><div><b>Wireshark Failure:</b></div><div><div><a href="https://ibb.co/ici8Ny" target="_blank">https://ibb.co/ici8Ny</a></div><div><br></div><div><b>Wireshark Working:</b></div><div><a href="https://ibb.co/kePF2y" target="_blank">https://ibb.co/kePF2y</a></div></div></div><div dir="ltr"><div><br></div>-- <br><div dir="ltr" class="m_-8423270369103637269m_1292628742324445911gmail_signature" data-smartmail="gmail_signature"><div dir="ltr">Callum Guy<div>Head of Information Security</div><div>X-on</div></div></div></div></blockquote></div>-- <br><div dir="ltr" class="gmail_signature" data-smartmail="gmail_signature"><div dir="ltr">Callum Guy<div>Head of Information Security</div><div>X-on</div></div></div>
<br>
<p dir="ltr" style="line-height:1.38;margin-top:0pt;margin-bottom:0pt;text-align:justify"><font size="3" face="Verdana"><span style="font-size:8px;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline"></span></font></p><img src="https://www.x-on.co.uk/email/footer/banner-surgeryconnect-june-july.jpg"><br><p><font size="4"><span style="font-size:8px;color:rgb(0,0,0);background-color:transparent;font-weight:400;font-style:normal;font-variant:normal;text-decoration:none;vertical-align:baseline"></span><b><sup><font face="Verdana">0333 332 0000 | <a href="http://www.x-on.co.uk" target="_blank">www.x-on.co.uk</a> | <sub> </sub></font></sup></b></font><font size="4"><b><sub><sup><font face="Verdana"><a href="https://www.linkedin.com/company/x-on" target="_blank"><img src="http://www.x-on.co.uk//images/icon/linkedin.png" width="24" height="24"></a> <a href="https://www.facebook.com/XonTel" target="_blank"><img src="http://www.x-on.co.uk//images/icon/facebook.png" width="24" height="24"></a> <a href="https://twitter.com/xonuk" target="_blank"><img src="http://www.x-on.co.uk//images/icon/twitter.png" width="24" height="24"></a></font></sup></sub> </b></font>
<span style="font-size:6.0pt;font-family:Verdana;color:black"><br>X-on
is a trading name of Storacall Technology Ltd a limited company registered in
England and Wales.<br>
Registered Office : Avaland House, 110 London Road, Apsley, Hemel Hempstead,
Herts, HP3 9SD. Company Registration No. 2578478.<br>
The information in this e-mail is confidential and for use by the addressee(s)
only. If you are not the intended recipient, please notify X-on immediately on <span>+44(0)333 332 0000</span> and delete the<br>message from your computer. If you are not a named addressee you must not use,
disclose, disseminate, distribute, copy, print or reply to this email. </span><span style="font-size:6.0pt;font-family:Verdana;color:black">Views
or opinions expressed by an individual<br>within this email may not necessarily
reflect the views of X-on or its associated companies. Although X-on routinely
screens for viruses, addressees should scan this email and any attachments<br>for
viruses. X-on makes no representation or warranty as to the absence of viruses
in this email or any attachments.</span></p>
<p><span style="font-size:6.0pt;font-family:Verdana;color:black"></span><font size="2"><span style="font-size:6.0pt;font-family:Verdana;color:black"></span></font></p>