Generate .cer and .key from a pfx file using a openssl utility
openssl pkcs12 -in [FILE].pfx -clcerts -nokeys -out[FILE].cer
openssl pkcs12 -in [FILE].pfx -nocerts -nodes -out [FILE].key
Delete a passphrase from kex file:
openssl rsa -in [fichier].key -out [new-fichier].key