Importing a Certificate into Mozilla Firefox

In Firefox, go to Tools > Options.
Go to the Advanced tab and the Security sub-tab and click View Certificates.
Go to the Authorities tab and click Import. Note that different tabs show different files without an extension indicating that they are native format
- Files with a .p12 extension are shown without the extension when you import from the Your Certificates tab
- Files with a .cer are shown without the extension when you import from the other certificate type tabs
This emphasises the value of understanding how the different types of certificate usage affect the type of file being used to transport a certificate. Other certificate stores may have different rules about formats. It is worth investigating they destination locations requirements before attempting to create certificate files for their use.
Specify the file that you exported from Internet Explorer.
A message should popup telling you that this certificate already exists. This confirms that file was correctly formatted and read by the import tool.