_ex_device_x509_cert_cmd.txt

openssl genpkey -out device1.key -algorithm RSA -pkeyopt 
openssl req -new -key device1.key -out device1.csr
openssl x509 -req -days 365 -in device1.csr -signkey device1.key -out device1.crt
openssl x509 -in device1.crt -out device1.pem -outform PEM
openssl x509 -in device1.crt -noout -fingerprint