Meinberg LANTIME, Operating Instructions Manual

Page: 89 / 153

If you enabled SSH, your LANTIME automatically is able to use secure file transfer
with SCP or SFTP protocol. The usage of FTP as a file transfer protocol is as insecure
as using TELNET for shell access.
Generate SSL Certificate for HTTPS
HTTPS is the standard for encrypted transmission of data between web browser
and web server. It relies on X.509 certificates and asymmetric crypto procedures. The
timeserver uses these certificates to authenticate itself to the client (web browser).
The first time a web browser connects to the HTTPS web server of your LANTIME,
you are asked to accept the certificate of the web server. To make sure that you are
talking to your known timeserver, check the certificate and accept it, if it matches the
one stored on the LANTIME. All further connections are comparing the certificate
with this one, which is saved in your web browser configuration. Afterwards you are
prompted to verify the certificate only when it changed.
By using the button “Generate SSL certificate for HTTP" you can create a new
certificate. Please enter your organisation, name, mail address and the location in the
upcoming form and press “Generate SSL certificate” to finally generate it.
NTP keys and certificates
The fourth and fifth section of the “Security” page allow you to create the needed
crypto keys and certificates for secure NTP operation (please see NTP authentication
below).
The function “Generate new NTP public key“ is creating a new self-signed certificate
for the timeserver, which is automatically marked as “trusted“.
Important note: This certificate is depending on the hostname of your LANTIME, it
is mandatory to recreate the certificate after changing the hostname. The certificates
are build with the internal command “ntp-keygen -T” (ntp-keygen is part of the
installed NTP suite). Your LANTIME is using the /etc/ntp/ directory for storing its
private and public keys (this is called the “keysdir”). Please refer to the chapter “NTP
Autokey” for further information (below).
The two options “Show NTP MD5 key“ and “Edit NTP MD5 keys“ allow you to
manage the symmetric keys used by NTP. More about that can be found in the
chapter about symmetric keys (below).
89