Creating and Applying SSL Certificates for Webmin Admin Interface

Prerequisites

Create Your SSL Certificate

  1. Launch XCA
  2. Open the PKI database if it is not already (File > Open DataBase), enter password
  3. Click on the Certificates tab, right click on your Intermediate CA certificate
  4. Select New
  5. On the Source tab, make sure Use this Certificate for signing is selected
  6. Verify your Intermediate CA certificate is selected from the drop down
  7. Click the Subject tab
  8. Complete the Distinguished Name section

    internalName: nettools.i12bretro.local
    countryName: US
    stateOrProvinceName: Virginia
    localityName: Northern
    organizationName: i12bretro
    organizationUnitName: i12bretro Certificate Authority
    commonName: nettools.i12bretro.local

  9. Click the Generate a New Key button
  10. Enter a name and set the key size to at least 2048
  11. Click Create
  12. Click on the Extensions tab
  13. Select End Entity from the type list
  14. Click Edit next to Subject Alternative Name
  15. Add any DNS or IP addresses that the certificate will identify
  16. Update the validity dates to fit your needs
  17. Click the Key Usage tab
  18. Under Key Usage select Digital Signature, Key Encipherment
  19. Under Extended Key Usage select Web Server and Web Client Authentication
  20. Click the Netscape tab
  21. Select SSL Server
  22. Click OK to create the certificate

Exporting Required Files

  1. In XCA, click on the Certificates tab
  2. Right click the SSL certificate > Export > File
  3. Set the file name with a .pem extension and verify the export format is PEM + Key (*.pem)
  4. Click OK

Applying the Certificates

  1. Download PuTTY Download
  2. Connect to the Linux host via PuTTY
  3. Install Webmin if it is not already installed
    wget http://prdownloads.sourceforge.net/webadmin/webmin_1.941_all.deb
    sudo dpkg -i webmin_1.941_all.deb
    sudo apt-get -f install
  4. Copy the certificates exported above to the Linux device
  5. Copy the certificates exported above to /etc/webmin
    cp /home/pi/Downloads/webmin.pem /etc/webmin
  6. Open a web browser and navigate to Webmin via https://DNSorIP:10000
  7. Login with the root username and password
  8. Navigate to Webmin > Webmin Configuration > SSL Encryption
  9. Click the browse button next to the Private key file field
  10. Navigate to /etc/webmin and select the webmin.pem certificate
  11. Make sure the certificate file is set to Same file as private key
  12. Click the save button
  13. Webmin will apply the certificate and restart
  14. Close the web browser and relaunch using the DNS or IP address setup in the SSL certificate