Can anyone help me with this?

I know that if you go to dev.missilesys.com, and download the cert you see that it is signed by International Weapons Export Inc.

so i created a root ca with the same name

than i created a csr with common name administrator

than i created a cert, i used the csr and the root ca i generated

after that i created a pfx, it's the same as p12 afaik, and tried to login i'm getting error 400

i wanted to use the original ca from the web site, i decoded the file p12, but i don't have the private key

anyone can help me? thanks

on the other side, if I create my own certificate using custom CSR and key, I still cannot sign it with website CA (taken from original p12 file) since I do not have the private key.