Derive private ed25519 SSH key from private PGP key.

GPG itself only supports exporting public SSH keys and other tools don't work for ed25519 keys.

• A tool exists to do this for RSA keys: openpgp2ssh but it does not seem to support ed25519 keys
• Work on gnupg was started for this feature, but never finished see this issue and commit: https://dev.gnupg.org/T6647

First you need to export your PGP key from GPG:

❯ gpg2 --export-secret-keys --armor [email protected] >priv-gpg

Then identify the public SSH key that was used to encrypt your secret. You can search for your GitHub username in: https://fluence-dao.s3.eu-west-1.amazonaws.com/metadata.json

If you have multiple subkeys, usually it is the authenticate key highlighted with [A] in the output of:

❯ gpg --list-secret-keys --with-keygrip

❯ go run main.go

It'll ask you for the path to your private PGP key, followed by choosing the key/subkey and if your PGP key is encrypted it'll ask for the passphrase.

In the output, verify that the public SSH key printed matches the one in metadata.json. If it matches, the last part of the output it will print the matching private SSH key. You can save the key to a file and use how you want.

If you want to decrypt a file that was encryptd by age with your public SSH key, you can just use age as normal to decrypt the file using the SSH private key that we've got in the previous step:

❯ age --decrypt --identity ./ssh-secret-key --output decrypted ./testfile.txt.age

This project was built with lots of headaches by pinpox & felschr. If you need help, feel free to contact us.

And if you want to thank us, you can send us any crypto or token to our Ethereum / Polygon wallets 😊:
pinpox: 0x3d479e19ae8d1a67becdaeaf8d2d37c8e425bd03 felschr: 0xD66753D737603E18018281E298Df86DE402d313E