Firefox

SourceSecure is on Firefox Add-ons: https://addons.mozilla.org/firefox/addon/sourcesecure/.

Firefox reads enterprise policy from a policies.json file, or from Group Policy or Intune with Mozilla's ADMX templates.

policies.json

Copy files/firefox-policies.json to:

• Windows: C:\Program Files\Mozilla Firefox\distribution\policies.json
• Mac: /Applications/Firefox.app/Contents/Resources/distribution/policies.json
• Linux: /etc/firefox/policies/policies.json

It force-installs the add-on sourcesecure@sourcesecure.ca from addons.mozilla.org and lets it run in private windows. If the computer already has a policies.json, merge the ExtensionSettings entry into it rather than replacing the file.

Group Policy or Intune

With Mozilla's templates (https://github.com/mozilla/policy-templates/releases), set Firefox > Extensions > Extension Management to the ExtensionSettings value from the file above.

Check it at about:policies and about:addons.