Create ECC (elliptic curve crypto) keys using curve 25519 with/for GPG

gpg_ecc-25519_keygen

#!/usr/bin/env -S gpg --batch --expert --gen-key
# Brief: Generate ECC PGP keys for signing (primary key) & encryption (subkey)
# Run as: chmod +x gpg_ecc-25519_keygen; ./gpg_ecc-25519_keygen
# Ref: https://www.gnupg.org/documentation/manuals/gnupg/Unattended-GPG-key-generation.html

%echo "Generating ECC keys (sign & encr) with no-expiry"
  %no-protection
  Key-Type: EDDSA
    Key-Curve: ed25519
  Subkey-Type: ECDH
    Subkey-Curve: cv25519
  Name-Real: dummy
  Expire-Date: 0
  # Now, let's do a commit here, so that we can later print "done" :-)
  %commit
%echo Done

I have a feeling the result is not for "signing" usage.
If you do not add the following line the result is encr only, but anyway it fails with specified Subkey-Usage not allowed for algo 18
Subkey-Usage: sign encrypt

@adamjrat I think thats because cv25519 is for encryption and ECDH while the primary key is used for signing. It should work with Subkey-Usage: encrypt and key-usage: sign.

Alternatively, you dont need to specify the key usages. The documentation says:

If no ‘Key-Usage’ is specified and the ‘Key-Type’ is not ‘default’, all allowed usages for that particular algorithm are used