Add self-signed CA certificates to the system trusted certificate store on macOS

Canonical version: https://support.apple.com/en-in/guide/keychain-access/kyca2431/mac

Add certificates to a keychain using Keychain Access on Mac

A certificate file can be shared between computers. You can add certificates to your keychain for quick access to secure websites and other resources.

1. In the Keychain Access app

   
   on your Mac, select either the login or System keychain.

2. Drag the certificate file onto the Keychain Access app or double-click it in Finder.

    

3. You should be challenged to provide administrator credentials.

    

4. Right click on the newly imported certificate and select Get Info. A dialog will open.

   

    

5. If the Trust section is not visible, click the disclosure triangle to the left of it.

   

    

6. Select the dropdown menu for When using this certificate: and select the Always Trust option.

   

    

7. Close the window containing the certificate information. You will be asked to authenticate as an administrator to accept the changes to the System certificate store.

    

8. Once complete, your self-signed certificate should indicate that it is "marked as trusted for all users" as shown here.