Audits against https://github.com/marmot-protocol/marmot surfaced several
deviations from the Marmot specs. This commit addresses them across three
tiers.
Wire-format / interop (Tier 1)
- MarmotGroupData: bump CURRENT_VERSION to 3 (MIP-01 v3), add
disappearing_message_secs field, validate version is supported, reject
value 0 for the disappearing duration.
- GroupEventEncryption: use empty AAD (ByteArray(0)) per MIP-03 instead of
binding nostr_group_id. Callers updated. This is wire-breaking against
the prior (non-compliant) encoder.
- Mip01ImageCrypto: new helper with HKDF derivations for the group image
encryption key (label "mip01-image-encryption-v2") and the Blossom
upload keypair seed (label "mip01-blossom-upload-v2").
- MarmotOutboundProcessor: auto-apply NIP-40 expiration tag on kind:445
events when the group has disappearing_message_secs configured.
Authorization / MLS (Tier 2)
- MlsGroup helpers: memberIdentity/myIdentityHex/currentMarmotData/
isLocalAdmin/isLeafAdmin.
- proposeSelfRemove / selfRemove: reject members listed in admin_pubkeys
(MIP-01: admins must self-demote first).
- MlsGroup.commit(): non-admin members may only commit a single self-Update
or SelfRemove-only proposals; admin-depletion guard rejects commits that
would leave the group without any admin.
- MlsGroup.create(): install the RFC 9420 required_capabilities extension
in the GroupContext and advertise marmot_group_data (0xF2EE) +
self_remove (0x000A) in the creator's leaf capabilities.
- MlsGroupManager.updateGroupExtensions: admin gate (relaxed during
bootstrap when no admins are yet configured).
- MlsGroupManager.memberIdentityHex: expose credential identity lookup.
- MarmotInboundProcessor: after MLS decrypt, verify the inner Nostr
event's pubkey matches the MLS sender's BasicCredential identity.
Hardening (Tier 3)
- Mip04IMetaTag: new Mip04ParseResult sealed class with explicit
DeprecatedV1 variant. parseMip04 logs a security warning when it
encounters mip04-v1 instead of silently returning null.
- Mip04MediaEncryption: expose LEGACY_VERSION_V1 = "mip04-v1" constant.
- MarmotWelcomeSender: new awaitCommitAck suspend parameter on
wrapWelcome / wrapWelcomeBytes so callers can plumb the Commit ack
wait through the sender (MIP-02 ordering requirement).
Tests
- MarmotMipComplianceTest covers MarmotGroupData v3 round-trip (with and
without disappearing_message_secs), constructor/decoder validation of
disappearing=0 and unsupported versions, Mip01ImageCrypto
determinism and label separation, and Mip04ParseResult v2/v1/invalid
classification.
https://claude.ai/code/session_014N7vG2TPgEeh7sQTpyHjJZ
Claude
1dc065f84a