The Unidesk Management Console uses Secure Sockets Layer (SSL) communication. When you enter the URL for the application, it automatically redirects you to a secure connection. If you specify HTTPS as the protocol in the URL and the application does not include a security certificate from a Certificate Authority, you are prompted to bypass the security warnings the first time you access the application.

To eliminate the security warning, upload a trusted certificate that you create.

Requirements

The trusted certificate must meet the following requirements:

1. It must be a Privacy Enhanced Mail (PEM) certificate.
2. It must include both the certificate and the key.
3. It does not include a passphrase.

Create a CSR

You need to generate a CSR file so you can give it to Certificate Provider for certificate request. Since ELM is based on CentOS Linux, it has OpenSSL included. 
You may use the tool mentioned at this link, https://www.digicert.com/easy-csr/openssl.htm. I found this helpful article from DigiCert support that automatically generates the required OpenSSL command.
You may then use Putty to log on to the console as root and pasted in the OpenSSL command, which will generate the CSR.
Please refer to openssl commands shared in OpenSSL Quick Reference Guide | DigiCert.com to generate CSR. 

Uploading the certificate

1. Create a PEM certificate.
2. Upload the certificate:
   1. Log in to the Unidesk CacheCloud Infrastructure Management utility. 
   2. Select Configuration > Upload SSL Certificate in the left pane.
   3. Browse to the self-signed PEM certificate file and click Upload.
3. Restart the Management Appliance.