openssl

It can be done using openssl:
openssl s_client -connect SERVER:PORT -showcerts

It can be done like this

openssl req -new -newkey rsa:2048 -nodes -keyout certificate.key -out certificate.csr


To extract private key:

• openssl pkcs12 -in file.pfx -nocerts -out pk.pem
• openssl rsa -in pk.pem -out key.pem

To extract certificate:

• openssl pkcs12 -in file.pfx -clcerts -nokeys -out cert.pem