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<p class="MsoNormal">Hi,<o:p></o:p></p>
<p class="MsoNormal">Having recently used stunnel on the phone as a server to encrypt the communication between an external client and a simple TCP server socket on the phone, one of the clients have raised the following….<o:p></o:p></p>
<p><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">Phone resets a TLS conection from client, when CBC protection is enabled on tomcat server.<o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">The phone syslog shows:
<br>
Oct 28 14:26:14 10 user.crit syslog: CommsChannelExtenderRx(28881): ./src/CommsChannelExtenderRx.cpp:186 Header section invalid<o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">To prevent a SSL/TLS BEAST attack (CVE-2011-3389) Oracle Java (JSSE) has implemented a CBC protection which can be set with System Property jsse.enableCBCProtection. The default value is true.<o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">What was done:<o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">Start client and connect it with a phone.<br>
The TLS connection is established, but then the phone resets the connection, and client is not working.<o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">When I set jsse.enableCBCProtection to false at the tomcat server, the phone accepts the connection and client is working.<o:p></o:p></span></p>
<p><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">To prevent man-in-the-middle attacks, the phone should be able to handle the fragmented TLS block when CBC protection is activated on the client tomcat server.<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I have been unable to find the appropriate stunnel configuration item to support this.<o:p></o:p></p>
<p class="MsoNormal">Please could you inform me how this is handled through stunnel.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thank you for your assistance and I look forward to your responses.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Thanks..<o:p></o:p></p>
<p class="MsoNormal">John<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">John Simner BSc(Hons) MSc CEng. MIET</span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif"">Software Engineer<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="FR" style="font-size:10.0pt;font-family:"Arial","sans-serif"">Unify Enterprise Communications Ltd.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="FR" style="font-size:10.0pt;font-family:"Arial","sans-serif"">Devices Development<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="FR" style="font-size:10.0pt;font-family:"Arial","sans-serif";color:red"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">K Block, Technology Drive, Beeston, Nottingham, NG9 1LA<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">Tel.: +44 (0) 19088 17378<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif"">Email:
<a href="mailto:vorname.name@unify.com">john.simner@unify.com </a><u><span style="color:blue"><o:p></o:p></span></u></span></p>
<p class="MsoNormal"><u><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:blue"><o:p><span style="text-decoration:none"> </span></o:p></span></u></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Arial","sans-serif""><a href="http://www.unify.co.uk/">www.unify.co.uk</a></span><span lang="EN-US" style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p></o:p></span></p>
<p class="MsoNormal" style="text-autospace:none"><span style="font-size:10.0pt;font-family:"Arial","sans-serif""><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:10.0pt;font-family:"Arial","sans-serif";color:black">Unify Enterprise Communications Limited. Registered Office: Brickhill Street, Willen Lake, Milton Keynes, MK15 0DJ<o:p></o:p></span></p>
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