<%NUMBERING1%>.<%NUMBERING2%>.<%NUMBERING3%> PRTG Manual: Using Your Own SSL Certificate with the PRTG Web Server

This section gives you a brief overview of how to use your own trusted Secure Sockets Layer (SSL) certificate files with the PRTG web server.

This only applies to PRTG on premises instances, not to PRTG hosted by Paessler.

What is SSL?

PRTG supports SSL to encrypt all data entered and shown in the PRTG web interface, in PRTG Desktop, or in the Mobile Apps. This ensures that no sensitive information can be intercepted when sending data between the PRTG core server and your client software.

By default, PRTG is delivered with an SSL certificate so you can use secure connections to your PRTG core server. However, this is a self-signed certificate, which is why browsers show an SSL certificate warning when you try to access the PRTG web interface. Despite this warning, your connection is still fully encrypted.

To remove the browser warning, you can obtain a certificate that is valid for your own domain name and signed by a valid authority. You can request your own trusted certificate from an issuer like GoDaddy, DigiCert, or InstantSSL, for example. You must provide the certificate in a suitable format and you have to import it correctly into your PRTG core server.

Importing Trusted SSL Certificates for PRTG

There are many different issuers for certificates, and there are different formats in which certificates can be provided. PRTG needs three different correctly named files containing data in the expected encoding and format. This can make manually importing an issued certificate slightly complicated because there are various certificate files that you must retrieve from a certificate authority (CA). So, to ease the installation of a trusted certificate, we provide the freeware tool PRTG Certificate Importer.

The PRTG Certificate Importer automatically combines and converts all files that a CA bundle contains for use with PRTG and stores the certificate files under the correct path on your PRTG core server. At best, you only provide the path to your received CA bundle and let the tool do the rest. We strongly recommend that you use the PRTG Certificate Importer if you want to install a trusted certificate for PRTG.

For more information about this tool and a download link, see the Paessler website: PRTG Certificate Importer

Manual Certificate Import

Although we recommend that you use PRTG Certificate Importer because it is much more comfortable, you can still import your trusted certificate manually. If you do so, note that PRTG requires three different certificate files in a Privacy-Enhanced Mail (PEM) encoded format, and an unencrypted private key:

prtg.crt: This is the certificate for your PRTG core server. It has to be stored in PEM-encoded format.
prtg.key: This is the private key matching your server certificate. It has to be stored in PEM-encoded format and must not be encrypted. Make sure that you provide this file in decrypted format. The best way to check this is to open the file in a text editor. If you find a line containing the word "ENCRYPTED", the file still needs to be decrypted before you can use it with PRTG. Decrypt it using an SSL tool (for example, OpenSSL) and your key password.
root.pem: This is the public root certificate of your certificate's issuer. It has to be stored in PEM-encoded format and must contain all necessary root certificates of your issuer in one file. If there is more than one PEM-encoded root certificate, use a text editor to copy all of them into a single file (the order does not matter).

PEM-encoded files must not contain Unix line breaks. Only Windows line breaks are supported.

Once ready, copy these three files to the \cert subfolder of the PRTG program directory (back up files before) and restart the PRTG core server service (see section PRTG Administration Tool).

The PRTG core server service is not able to start if the files are not provided in exactly the expected format.

For detailed instructions and examples, installation descriptions for various certificates (including Wildcard certificates), as well as links to certificate tools and converters, see section More.

KNOWLEDGE BASE

How can I establish a secure web interface connection to PRTG?

https://kb.paessler.com/en/topic/273

How can I use a trusted SSL certificate with the PRTG web interface?

https://kb.paessler.com/en/topic/283

PAESSLER TOOLS

PRTG Certificate Importer: Installing Trusted SSL Certificates for PRTG Network Monitor

https://www.paessler.com/tools/certificateimporter

Advanced Topics