Tool that converts PGP private Eliptic Curve keys to ASN1 DER format. This format can be used to convert further to PEM, PKCS8, SSH, etc with for instance openssl.

I needed this to be able to put my offline nistp384 keys on my PIV smartcard for work.

For RSA already many tools are available. Tools that do elliptic curves are not so wide supported. Luckily Bouncing Castle does support them.

Unfortunately, ED25519 keys are not supported yet in this tool, since I don't use them on smartcards, but it should not be hard to add.