While working on #Fedify, I noticed something about how #Misskey handles #ActivityPub object access. When a remote server requests a followers-only post or DM with a valid HTTP Signatures (draft-cavage) from an authorized actor, Misskey still returns 404 instead of the content. It seems Misskey only checks the visibility field (public/home) without verifying the signature at all.
#Mastodon takes a different approach—when #authorized_fetch is enabled, it validates the HTTP Signatures and returns the content if the requesting actor has permission. I think it would be beneficial if Misskey could adopt a similar mechanism, since it would better respect the access control semantics that ActivityPub intends. Has anyone else run into this, or are there specific reasons Misskey handles it this way?