How to install P12 certificates in mobile Firefox? I successfully imported my .p12 certificate to my two android devices (Galaxy Tab E SM-T560 (Spreadtrum SoC) running Kitkat 4.4.4 and Xiaomi Mi A1 Global Version (SD 625)(was) running (Oreo 8.0.0) Pie 9.0 . Now I would like to import the cert  to Firefox on both devices, but I don't actually know what to do. I searched for answers on reddit, but couldn't find a general procedure to do this. Is this even an option in the mobile version of Firefox?
At this time, Firefox for Android does not support importing a PKCS #12 certificate.  This is bug 868370.

If you have root access to your device, you can import it manually using a Linux computer attached to the phone with adb.

If your client certificate came from a &lt;keygen&gt; form, you can use the same form in Firefox for Android to generate and install a new certificate directly (skipping the PKCS #12 step).