I downloaded an existing certificate from a sandbox, so I have the .crt file. Now I want to use this certificate in another sandbox. Unfortunately Salesforce only allows you to import a .jks (Java Keystore) file. I failed to generate one of these not knowing I would need it to import it in another Salesforce instance, so all I have is the .crt file. Is there any workaround to getting the certificate uploaded back into Salesforce?
There's an excellent post here at stackexchange providing the answer: