nimbus-eth2/beacon_chain/gossip_processing
Etan Kissling ecaf6c8e92
harden gossip `strictVerification` in local testnets (#4880)
Fail local testnets on any gossip REJECT, instead of just asserting some
of the attestation related checks. This now also ensures that blocks,
BLS to Execution changes, blob sidecars and LC messages are checked
when running in a local testnet environment (`--verify-finalization`).

https://github.com/status-im/nimbus-eth2/pull/2904#discussion_r719603935
2023-05-02 13:06:02 +02:00
..
README.md automatic update of v1.3.0-rc.5 consensus spec URLs to v1.3.0 (#4848) 2023-04-21 18:52:43 +00:00
batch_validation.nim refactor batch validation not to require genesis_validators_root each time (#4640) 2023-02-20 09:26:22 +01:00
block_processor.nim include small dedup in block processor to handle blockByRoot blocks (#4850) 2023-04-26 07:00:03 +00:00
eth2_processor.nim Fill in missing BlobSidecar gossip check (#4863) 2023-04-26 17:33:33 +00:00
gossip_validation.nim harden gossip `strictVerification` in local testnets (#4880) 2023-05-02 13:06:02 +02:00
light_client_processor.nim harden gossip `strictVerification` in local testnets (#4880) 2023-05-02 13:06:02 +02:00
optimistic_processor.nim remove Nim 1.2-compatible `push raise`s and update copyright notice years (#4528) 2023-01-20 14:14:37 +00:00

README.md

Gossip Processing

This folder holds a collection of modules to:

  • validate raw gossip data before
    • rebroadcasting it (potentially aggregated)
    • sending it to one of the consensus object pools

Validation

Gossip validation is different from consensus verification in particular for blocks.

There are multiple consumers of validated consensus objects:

  • a ValidationResult.Accept output triggers rebroadcasting in libp2p
    • We jump into method validate(PubSub, Message) in libp2p/protocols/pubsub/pubsub.nim
    • which was called by rpcHandler(GossipSub, PubSubPeer, RPCMsg)
  • a blockValidator message enqueues the validated object to the processing queue in block_processor
    • blockQueue: AsyncQueue[BlockEntry] (shared with request_manager and sync_manager)
    • This queue is then regularly processed to be made available to the consensus object pools.
  • a xyzValidator message adds the validated object to a pool in eth2_processor
    • Attestations (unaggregated and aggregated) get collected into batches.
    • Once a threshold is exceeded or after a timeout, they get validated together using BatchCrypto.

Security concerns

As the first line of defense in Nimbus, modules must be able to handle bursts of data that may come:

  • from malicious nodes trying to DOS us
  • from long periods of non-finality, creating lots of forks, attestations