Import self-signed certificate to Android and iOS


I’m working on an ionic app that synchronizes with a server. The Synchronization should use ssl for security reasons. The clients of our company host this server that is used for the synchronisation and some of them use self-signed certificates for the https connection. For usability Reasons i want the app to automatically download the cer file and open up the systems import dialog for the certificates. But i can’t get this dialog to show up. I tried with FileOpener2 from ngCordova and testet some different mime Types (“application/x-x509-ca-cert”, “application/pkix-cert”) but there appears only a toast message that says, that the certificate couldn’t be red. Does anybody have an idea or a solution to programmatically open the system dialog with the cer file?