russell@unturf.com
aa8caeeece
Phase 1 of the federation/gossip layer fox sketched as the natural
extension of v9.8 admissibility's content-addressed identity. Two
peers ingesting the same dump already compute identical document_roots
and identical 8-dim cache_keys; the mesh layer is the wire-and-trust
plumbing that lets them dedup answers, exchange Merkle proofs, and
cleanly distrust an evicted member without a hard fork.
Cryptography (cryptography lib, audited):
Ed25519 — every membership mutation + (future) gossip envelope
is signed by the actor's pubkey.
X25519 ECDH — wraps each epoch's symmetric mesh secret to every
current member's DH pubkey via HKDF-derived AEAD key.
ChaCha20-P1305— AEAD for envelope payloads + per-member secret wrap.
State machine:
mesh_identity — singleton; this peer's keys + group name
mesh_roster — per-epoch (member_id, sign_pub, dh_pub, role)
mesh_epochs — epoch_id -> {started_at, started_event_hash,
secret_envelope JSON, reason}
meta:mesh.enabled flag — off by default; gates everything
Eviction works by rotating to a new epoch whose envelope omits the
kicked member. Their prior signatures stay verifiable (the older
roster row is retained), but any gossip from epoch+1 onward is
opaque to them — the secret was never shared with their pubkey.
Authority gate: only roster members with role='admin' can add or
kick. Self-kick is rejected explicitly. The last admin can't be
kicked. Schedule-rotate (refresh secret, no roster change) is open
to any current member as a session-hygiene op.
Audit-chain integration: every mesh state mutation writes an audit
event (mesh_init, mesh_enable/disable, mesh_epoch_rotate). The
epoch's started_event_hash backfills into mesh_epochs after the
audit row commits, giving each epoch a tamper-evident pin into the
ledger.
CLI subcommands: mesh init, mesh status, mesh enable, mesh disable,
mesh members, mesh add, mesh kick, mesh rotate. All read-only or
local-state-only — no network code paths in this commit.
The HTTP gossip wire (`mesh sync`, `mesh serve`) is the next phase.
Schema, cryptography, and roster state machine are all in place to
support it without further migration.
65 lines
1.8 KiB
Python
65 lines
1.8 KiB
Python
"""Mesh — gossip / membership layer for federated aborist trees.
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Off by default. Loaded only when the user explicitly opts in via
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`aborist mesh init` (creates this peer's identity) and
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`aborist mesh enable` (flips the gating flag in the meta table).
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The cryptographic substrate:
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- Ed25519 (signing) — every gossip message and every membership
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mutation event is signed by the sender's pubkey.
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- X25519 (ECDH) — used to wrap each epoch's symmetric mesh
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secret to every current member's DH pubkey, so the new secret
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is reconstructible only by the post-rotation roster.
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Membership state is per-epoch:
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epoch 0 = group genesis (just the founder)
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epoch N = the N-th roster mutation (add member, kick, scheduled rotate)
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Eviction is a rotate where the kicked member's pubkey isn't in the
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new envelope. Their previously-signed events stay verifiable forever
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(historical roster preserved in mesh_roster), but they no longer have
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the new secret, so any AEAD-protected gossip for epoch N+1 is opaque
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to them.
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This module deliberately avoids networking. The wire layer (HTTP/TLS
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gossip server + sync client) lives in `aborist.mesh.wire` and is also
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opt-in.
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"""
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from aborist.mesh.crypto import (
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aead_decrypt,
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aead_encrypt,
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ecdh_shared_secret,
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generate_dh_keypair,
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generate_signing_keypair,
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sign,
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verify,
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)
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from aborist.mesh.state import (
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MESH_ENABLED_KEY,
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MeshIdentity,
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MeshRosterEntry,
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current_epoch,
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init_identity,
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is_enabled,
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load_identity,
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set_enabled,
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)
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__all__ = [
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"MESH_ENABLED_KEY",
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"MeshIdentity",
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"MeshRosterEntry",
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"aead_decrypt",
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"aead_encrypt",
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"current_epoch",
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"ecdh_shared_secret",
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"generate_dh_keypair",
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"generate_signing_keypair",
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"init_identity",
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"is_enabled",
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"load_identity",
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"set_enabled",
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"sign",
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"verify",
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]
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