Getting "Ill-formed input" in ostree sign

[ganjiii3]

Hi!
I wanted to try composefs with the verification of the userspace by ostree-prepare-root, however I am not able to pass the ed25519 key to ostree sign .

I've generated the key using
openssl genpkey -algorithm ed25519 -out private.key
and took only the base64-encoded part, and tried to pass it using both --keys-file and <KEY-ID> arguments to ostree sign. In either way, I get:

OT: using fuse: 0
OT: using fuse: 0
error: Invalid ed25519 secret key: Ill-formed input: expected 48 bytes, got 64 bytes

While inspecting the code, I found that the outputs of validate_lenght function are probably swapped, but also that the comments suggest that the API accepts also keys in binary format. So I've tried OpenSSL key in DER format, getting output:

OT: using fuse: 0
OT: using fuse: 0
error: Invalid ed25519 secret key: Ill-formed input: expected 0 bytes, got 64 bytes

Could you please take a look? 😅 I'm using latest Fedora Kinoite 41, the output of ostree --version:

libostree:
 Version: '2024.9'
 Git: 14e29775963d44bc533715efcf2362d6051756de
 Features:
  - inode64
  - initial-var
  - libcurl
  - libsoup3
  - gpgme
  - composefs
  - ex-fsverity
  - libarchive
  - selinux
  - openssl
  - sign-ed25519
  - libmount
  - systemd
  - release
  - p2p

Resources I've been following:
https://ostreedev.github.io/ostree/composefs/
https://blogs.gnome.org/alexl/2024/01/15/testing-composefs-in-silverblue/
#2867