This is an example of how to create a PGP signature via a YubiHSM2. It is intended to primarily serve as a test and example for both yubihsm-rs and pretty-good, and as such is essentially a proof-of-concept that isn't ready to be used.
If you want to try it out, you'll need to have a YubiHSM2, and you'll need to have an existing GPG
key you want to import onto the YubiHSM2. In order to do so, you'll also need the openpgp2pem tool
from Monkeysphere.
$ gpg --export-options export-reset-subkey-passwd --export-secret-keys ${YOUR_SUBKEY_ID}! |
openpgp2pem ${YOUR_SUBKEY_ID} > private_key.pem
private_key.pem can then be imported onto the YubiHSM2 via yubihsm-shell.