Howto enable NTP autokey on CentOS7 with RSA-MD5

<p>To make old RSA-MD5 keys generation and usage with newer versions of RedHat/CentOS openssl (1.0.1e), you have to set an environment variable:</p>
<pre class=" ">OPENSSL_ENABLE_MD5_VERIFY=1</pre>
<p><br />both when you invoke ntp-keygen and on server start (by setting it in /etc/default/ntpd)</p>