title: OpenSSL Client authentication fails with expecting trusted certificate
body: <p>I am following the <a href="https://support.f5.com/csp/article/K14819#test" rel="nofollow noreferrer">F5 KB article</a> to test SSL client based cert auth using openssl s_client but it keeps failing with this error:</p>
  
  <pre><code>OpenSSL&gt; s_client -connect auc.akmlab.local:443 -key "C:\HELPAG\akmlab files\certs\admin-c-auth-ca-cert2.key" -cert "C:\HELPAG\akmlab files\certs\admin-c-auth-ca-cert.crt"
  unable to load certificate
  8204:error:0909006C:PEM routines:get_name:no start line:crypto\pem\pem_lib.c:745:Expecting: TRUSTED CERTIFICATE
  error in s_client
  OpenSSL&gt;
  </code></pre>
  
  <p>I am trying to google for this but cannot find much info anyway related to SSL client auth.</p>
  
  <p>I have imported this same user cert to my browser and this works fine. </p>
  
  <p>The server is a f5 bigip device with the root certificate from the CA which has signed the user certificated.</p>