How can I programmatically add a cert to installed browsers?

I have a cert generated through a custom protocol and I would like to add it to a browsers store (and and all browsers: ie, firefox, chrome, safari) so that it can use it to authenticate. How can I accomplish t开发者_开发技巧his?

Firefox stores certificates in the three .db files in the user profile. So you would need to go through all existing profiles and change them. That can be done using NSS, particularly the certutil command line tool and for PKCS #12 files also pk12util. Depending on your goals you could of course also integrate NSS into your application and call its functions without using any command line tools. Note that IMHO adding a client certificate requires entering the master password for the database if one is set.