Unwrap yubihsm wrapped keys

Usage:

java -jar yubihsm-unwrap.jar <wrapped-key-file> <wrapping-key-file> [output-key-file]

Where:

wrapped-key is the wrapped blob in base64
wrapping-key is the wrapping key (hex)
output-key is the output key file (optional, pem)

Password during export is optional.

This is the reverse of what yhwrap utility does.