From Fedora Project Wiki
As yourself, in your ~/.bashrc add: export NSS_DEFAULT_DB_TYPE=sql If you are using ~/.cshrc add instead setenv "NSS_DEFAULT_DB_TYPE sql")
As yourself (not as root!!!) execute "certutil -N -d sql:/etc/pki/nssdb" If you supply a password, this password will eventually become your new firefox/thunderbird master password.