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<pre><span lang="EN-US" style="color:black">Hi Ross,<br><br><o:p></o:p></span></pre>
<pre><span lang="EN-US" style="color:black"><o:p> </o:p></span></pre>
<pre><span lang="EN-US" style="color:black">Live555 does not handle the use case where a receiver joins an ongoing SRTP session. <br><br><o:p></o:p></span></pre>
<pre><span lang="EN-US" style="color:black"><o:p> </o:p></span></pre>
<pre><span lang="EN-US" style="color:black">Actually, the server must provide the receiver with the value of the rollover counter (ROC) the sender is currently using. <br><br><o:p></o:p></span></pre>
<pre><span lang="EN-US" style="color:black">According to RFC 3830, section 6.1.1 :<br><br><o:p></o:p></span></pre>
<pre><span lang="EN-US" style="color:black">“ROC_i (32 bits): Current rollover counter used in SRTP. If the SRTP session has not started, this field is set to 0. This field <o:p></o:p></span></pre>
<pre><span lang="EN-US" style="color:black">is used to enable a member to join and synchronize with a already started stream.”<br><br><o:p></o:p></span></pre>
<pre><span lang="EN-US" style="color:black"><o:p> </o:p></span></pre>
<pre><span lang="EN-US" style="color:black">However, the ROC sent by live555 is always 0.<br><br><o:p></o:p></span></pre>
<pre><span lang="EN-US" style="color:black"><o:p> </o:p></span></pre>
<pre><span lang="EN-US" style="color:black">To reproduce the issue :<br><br><o:p></o:p></span></pre>
<pre><span lang="EN-US" style="color:black"><o:p> </o:p></span></pre>
<pre><span lang="EN-US" style="color:black">1- Configure testOndemandeServer to use SRTP. <br><br><o:p></o:p></span></pre>
<pre><span lang="EN-US" style="color:black"><o:p> </o:p></span></pre>
<pre><span lang="EN-US" style="color:black">2- Configure live555ProxyServer to use SRTP.<br><br><o:p></o:p></span></pre>
<pre><span lang="EN-US" style="color:black"><o:p> </o:p></span></pre>
<pre><span lang="EN-US" style="color:black">3- Connect a first openRT</span><span lang="EN-US" style="color:#1F497D">S</span><span lang="EN-US" style="color:black">P client to testOndemandeServer through live555ProxyServer using RTSPS.<br><br><o:p></o:p></span></pre>
<pre><span lang="EN-US" style="color:black"><o:p> </o:p></span></pre>
<pre><span lang="EN-US" style="color:black">4- Wait until the rollover counter is set to 1. <br><br><o:p></o:p></span></pre>
<pre><span lang="EN-US" style="color:black"><o:p> </o:p></span></pre>
<pre><span lang="EN-US" style="color:black">5- Connect a second openRTSP client to testOndemandeServer through live555ProxyServer using RTSPS.<br><br><o:p></o:p></span></pre>
<pre><span lang="EN-US" style="color:black"><o:p> </o:p></span></pre>
<pre><span lang="EN-US" style="color:black">6- The second openRTSP client will fail to authenticate received SRTP packets.<br><br><o:p></o:p></span></pre>
<pre><span lang="EN-US" style="color:black"><o:p> </o:p></span></pre>
<pre><span lang="EN-US" style="color:black">Thanks<o:p></o:p></span></pre>
<pre><span lang="EN-US" style="color:black"><br><br><o:p></o:p></span></pre>
<pre><span lang="EN-US" style="color:black">Yahia Benmoussa<o:p></o:p></span></pre>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<pre><span lang="EN-US" style="color:black"><o:p> </o:p></span></pre>
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