How to create an self-signed Certificate with Openssl? Step-by-step Open a terminal window on your system and follow these steps: 1.- Create a new private key sudo openssl genrsa -aes256 -out private.key 2.- Generate a certificate sudo openssl req -x509 -days 1000 -new -key private.key -out iam-sync-tenantidp3.soffidnet.pem 3.- Export to PKCS12 sudo openssl pkcs12 -export -in iam-sync-tenantidp3.soffidnet.pem -inkey private.key -out iam-sync-tenantidp3.soffidnet.pfx