Simple PFX generation (source)
openssl genrsa 2048 > private.pem
openssl req -x509 -new -key private.pem -out public.pem # fill options
openssl pkcs12 -export -in public.pem -inkey private.pem -out mycert.pfx
openssl genrsa -des3 -passout pass:x -out server.pass.key 2048
openssl rsa -passin pass:x -in server.pass.key -out server.key
openssl req -new -key server.key -out server.csr # fill options
openssl x509 -req -sha256 -days 365 -in server.csr -signkey server.key -out server.crt