Message Validation

[MatheusFranco99]

Overview

This PR updates the message validation module.

It adds a MessageValidator structure that implements the ValidatorForTopic function, as defined by the libp2p framework.

Its main validation function starts a chain of validation checks for the pub-sub, syntax, semantics, QBFT and duty logic rules.

Documentation and message rate estimation

The PR also updates the message validation and scoring documentation in p2p/SPEC.md and p2p/SCORING.md. The go code for the message rate estimation is added (along with tests) since this estimation is referenced by the scoring documentation.

Tests

This PR also adds tests for each implemented rule, as can be seen in the following list.

PubSub

• [x] PubSub message with empty data
• [x] PubSub message with a data bigger than the allowed size
• [x] PubSub message that can't decode a SignedSSVMessage

Syntax validation

• [x] No signers
• [x] No signatures
• [x] Wrong RSA signature size
• [x] Signers not sorted
• [x] Zero signer
• [x] Duplicated signer
• [x] Signers and signatures with different lengths
• [ ] Nil SSVMessage. This test can't be implemented due to the internals of ssz decoding
• [x] Empty data
• [ ] SSVMessage with data above the allowed limit. This test can't be implemented due to ssz encoding errors.
• [x] Undecodable SSVMessage.Data for consensus message
• [x] Undecodable SSVMessage.Data for partial signature message
• [x] Undecodable PrepareJustificaiton
• [x] Undecodable RoundChangeJustification

General semantics validation

• [x] Signer not in committee
• [x] Wrong domain
• [x] Invalid role
• [x] Unknown validator
• [x] Validator not attesting
• [x] Validator liquidated
• [x] Non-xistent CommitteeID
• [x] Incorrect topic
• [x] DKG Message
• [x] Unknown MessageType

Consensus semantics validation

• [x] Non-decided with multiple signers
• [x] Decided with not enough signers
• [x] Prepare with FullData
• [x] Commit with FullData
• [x] Invalid root
• [x] Unknown QBFT MessageType
• [x] Zero round
• [x] Mismatched identifier

Consensus QBFT logic validation

• [x] Signer not leader in proposal message
• [x] Decided with the same signers as previous message
• [x] Duplicated proposal with different FullData
• [x] Duplicated consensus message
• [x] Round not allowed considering time spread
• [x] Round already advanced
• [x] Unexpected RoundChangeJustification in Prepare message
• [x] Unexpected RoundChangeJustification in Commit message
• [x] Unexpected PrepareJustification in Prepare message
• [x] Unexpected PrepareJustification in Commit message
• [x] Unexpected PrepareJustification in RoundChange message

Consensus duty logic validation

• [x] Unexpected consensus message for ValidatorRegistration
• [x] Unexpected consensus message for VoluntaryExit
• [x] Round too high

Partial signature semantics validation

• [x] Multiple signers
• [x] With FullData
• [x] Invalid type
• [x] Type mismatch with role
• [x] No PartialSignatureMessages
• [ ] Wrong partial signature size. This test can't be implemented due to ssz encoding errors
• [x] Inconsistent signers
• [x] Validator index mismatch considering the validator public key

Partial signature duty logic validation

• [x] Type count
• [x] Too many signatures
• [x] Triple ValidatorIndex

General duty logic validation

• [x] Slot already advanced
• [x] Message sent before slot starts
• [x] Late slot
• [x] No proposer duty
• [x] No SyncCommitteeContribution duty
• [x] Too many duties

Wrong signature

• [x] Wrong signature

Valid

• [x] Happy flow

[alan-ssvlabs]

Maybe p2p/SPEC.md needs some update at line 268-283 about Basic Validation

[MatheusFranco99]

@alan-ssvlabs Indeed. Thanks!

[MatheusFranco99]

@GalRogozinski @alan-ssvlabs

In the p2p/SCORING.md file I have a code snippet for the message rate estimation. What do you guys think of creating a file with this code? The fact that p2p scoring needs it may be enough reason to add it. Also, the SSV repo uses exactly this function.

[MatheusFranco99]

@GalRogozinski @alan-ssvlabs Moved the msg estimation code to a go file and added some tests.