Paste your Certificate
To use this option, you must first open a certificate in a text editor or some other program and copy the contents to the clipboard. Then, right-click inside the dialog box and click Paste. Your certificate will be inserted into the dialog box.
Read from File
This button allows you to browse your system for a certificate and import it into the dialog box.
Note: The certificate you import must be either Binary DER format or Base64 format. This only imports user certificates, not private keys.