Steps to generate self-signed document signing certificate for testing OpenSign

# execute below command and use passphrase 'opensign'
openssl genrsa -des3 -out ./local_dev.key 2048
openssl req -key ./local_dev.key -new -x509 -days 365 -out ./local_dev.crt
openssl pkcs12 -inkey ./local_dev.key -in ./local_dev.crt -export -out ./local_dev.pfx
openssl base64 -in ./local_dev.pfx -out ./base64_pfx