A draft-cavage hs2019 signature leaves the hash to the key: with an RSA key it is tried with SHA-256, as nearly everyone
signs, then with SHA-512, as some do; rsa-sha256 stays SHA-256 only. A Digest of SHA-512= is checked as SHA-256= is.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw
Owner decision of 2026-10-06 (FEP-8fcf). A persona's delivery addressed to its followers carries a signed
Collection-Synchronization header naming its followers, its roll-call (…/groupies/roll-call) and the digest of its
accepted followers on the receiving server only. The roll-call answers a signed request with the persona's followers
on the signer's server and nobody else's.
Mastodon gives every Undo{Follow} it sends after reading a roll-call the same id (…#follows//undo), so a second one
looked like a copy: an Undo of a Follow that comes again while the follow it ends exists again is now kept once per
follow.
Checked live (scenarios/followsync.sh): Mastodon drops a follow PrivaPub lost, and undoes one it lost itself.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01LsXgEaXee4GCU1hwYgPJXw
InboxReceiver records each answer once, in a finally, with a reason: too-large, not-json,
not-activity, missing-type-or-actor, no-signature, the signature check's own codes
(headers-unsigned, digest-mismatch, header-unreadable, date-skew, expired,
algorithm-unsupported), signature-invalid, actor-not-key-owner, key-unavailable,
id-cross-origin, undo-foreign, misattributed, unknown-recipient, and for 202s queued,
duplicate, suspended or self-delete-unknown-key. Each event carries the activity and object
type, the inbox, the signature scheme, the bytes and the time taken. A 404 for an unknown
/mouth and a rate-limited inbox (429, from OnRejected) are recorded too.
Until the signature verifies, the host is only claimed, so it is kept only if the server is
already known. A suspended server is recorded under its own name.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01ELjqpznMFMNrJoJUj6K5p2
S6 of the roadmap. An inbox POST is refused unless its signature covers
(request-target) and host, as well as the digest and a date or (created).
The Date or (created) may be at most an hour old and fifteen minutes ahead
(it was twelve hours either way), and an (expires) in the past is refused.
The request target is read raw from the server, so a percent-encoded path
verifies as the sender signed it.
Tests cover a Mastodon-shaped delivery and each way of tampering with it,
plus a round trip of our own outbound signature.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012CzABvBkbcFqoHdmi8b9WB
Services/Federation and Controllers/ServerToServer become
Federation/{Actors,Signing,Inbox,Outbox,Rendering,Controllers}, the first step
of the roadmap's layout. No type, route or behaviour changes.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012CzABvBkbcFqoHdmi8b9WB
thepraandClaude Opus 5.5