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<div>Hello,</div>
<div><font face="Calibri" size="2"><span style="font-size:11pt;"> </span></font></div>
<div>We’re using OpenSSl 1.1.1b on WIN64 and are facing a (rare but strange) core-dump when doing the following:</div>
<div> </div>
<div>After successful TLS1.3 handshake we’re calling SSL_read() to get the first 2 Bytes of PDU data from the new connection (ASN.1 TAG + length).</div>
<div>SSL_read() returns 0</div>
<div>According to OpenSSL 1.1.1 documentation:</div>
<div> </div>
<div><font face="Calibri" size="2"><span style="font-size:11pt;"><i>For SSL_read() and SSL_peek() the following return values can occur:</i></span></font></div>
<div><font face="Calibri" size="2"><span style="font-size:11pt;"><i><= 0</i></span></font></div>
<div style="margin-top:5pt;margin-bottom:5pt;padding-left:36pt;"><font face="Times New Roman" size="3"><span style="font-size:12pt;"><i>The read operation was not successful, because either the connection was closed, an error occurred or action must be taken
by the calling process. Call </i><a href="https://www.openssl.org/docs/man1.1.1/man3/SSL_get_error.html"><font color="blue"><i><u>SSL_get_error(3)</u></i></font></a><i> with the return value </i><b><i>ret</i></b><i> to find out the reason.</i></span></font></div>
<div><font face="Calibri" size="2"><span style="font-size:11pt;"> </span></font></div>
<div>We follow and call SSL_get_error() which crashes with debugger output (only topmost frame is shown here)</div>
<div> </div>
<div><font color="red">LIBSSL!SSL_get_error(struct ssl_st * s = 0x00000000`05be9a00, int i = <Value unavailable error>)+0x18c [d:\data\openssl\64\openssl-1.1.1b\ssl\ssl_lib.c @ 3560] </font></div>
<div><font face="Calibri" size="2"><span style="font-size:11pt;"> </span></font></div>
<div>The <font color="#1F497D">OpenSSL </font>source at this <font color="#1F497D">reported </font>line looks like:</div>
<div> </div>
<div> if ((s->shutdown & SSL_RECEIVED_SHUTDOWN) &&</div>
<div> (s->s3->warn_alert == SSL_AD_CLOSE_NOTIFY))</div>
<div> return SSL_ERROR_ZERO_RETURN;</div>
<div><font face="Calibri" size="2"><span style="font-size:11pt;"> </span></font></div>
<div>when we inspect the session “s” <font color="#1F497D">in the debugger, </font>we find that s->shutdown == 3 and s->s3 == NULL which finally causes the crash</div>
<div> </div>
<div>It looks like a bug in OpenSSL….??? </div>
<div> </div>
<div><font color="#1F497D">So far i<font color="black">t happened only once in our LAB (after some hours of heavy SSL load</font> testing with thousands of SSL connections created/deleted<font color="black">….)<br>
we’re currently not able to reproduce it…..</font></font></div>
<div>Any comments/ideas/fixes would be appreciated……</div>
<div> </div>
<div><font face="Calibri" size="2" color="#1F497D"><span style="font-size:11pt;"> </span></font></div>
<div><font face="Calibri" size="2" color="#1F497D"><span style="font-size:11pt;"> </span></font></div>
<div><font size="2"><span style="font-size:9pt;"><b>Gerhard Jahn</b></span></font></div>
<div><font size="2"><span style="font-size:8.5pt;">Senior Developer IAM – AITs GER BDS CySP DIRX PDM</span></font></div>
<div><font size="1"><span style="font-size:8pt;">T +49 (0) 211 399 33276<br>
T +49 (0) 211 399 22891<br>
<a href="mailto:gerhard.jahn@atos.net"><font face="Calibri" size="2" color="blue"><span style="font-size:11pt;"><u>gerhard.jahn@atos.net</u></span></font></a></span></font></div>
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