openssl create self signed key pair code example
Example: openssl generate self signed certificate
openssl.exe genrsa -out <yourcertname>.key 4096
openssl.exe req -new -key yourcertname.key -out yourcertname.csr
openssl.exe genrsa -out <yourcertname>.key 4096
openssl.exe req -new -key yourcertname.key -out yourcertname.csr