open ssl command

openssl genrsa -out pri.pem 2048
openssl rsa -inform PEM -in pri.pem -outform D -out pri.der
openssl rsa -pubout -inform DER -in pri.der -outform D -out pub.derk

openssl genrsa -out test_key0_pri.pem 2048
openssl rsa -inform PEM -in test_key0_pri.pem -outform D -out test_key0_pri.der
openssl rsa -pubout -inform DER -in test_key0_pri.der -outform D -out test_key0_pub.der
openssl rsa -pubout -inform DER -in test_key0_pri.der -outform PEM -out test_key0_pub0.pem
openssl rsa -pubout -inform PEM -in test_key0_pri.pem -outform PEM -out test_key0_pub.pem