User Agent: Mozilla/5.0 (iPhone; CPU iPhone OS 11_2 like Mac OS X) AppleWebKit/604.4.7 (KHTML, like Gecko) Version/11.0 Mobile/15C5110b Safari/604.1 Steps to reproduce: Enterprises commonly issue a certificate to a user for authenticating to resources. This certificate is issue in macOS to the user’s login Keychain. Firefox currently does not support accessing certificates from macOS Keychain, making it impossible for an enterprise to fully support Firefox for users. The only work around is to export the certificate from Keychain and import it into Firefox manually. As most enterprise security policies prevent the installation of such certificates the a clients device with exportability, Firefox cannot be supported on the same leve as Safari and Chrome (which both use Keychain for certificate storage). Actual results: No ability to use a properly issued certificate (SSO) from Keychain in macOS Expected results: Firefox should have native support for certificates from Keychain.