Simplex QuorumCertificate and BLS aggregator

[samliok]

Why this should be merged

Implements the simplex QuorumCertificate, QCDeserializer and SignatureAggregator interfaces. This allows simplex to parse, aggregate and verify quorum certificates(ex. finalizations and notarizations) during execution.

How this works

• Builds on top of the BLSVerifier to handle BLS signatures and public keys.
• The bytes of a QC are serialized with asn1

How this was tested

Added unit tests to bls_test.go.

Need to be documented in RELEASES.md?

no

[Copilot]

Pull Request Overview

Implements BLS-based quorum certificates and aggregation for the Simplex consensus engine, along with test utilities and configuration.

• Adds testValidatorInfo and newEngineConfig in simplex/test_util.go to bootstrap BLS-based engine tests.
• Introduces QC, QCDeserializer, and SignatureAggregator in simplex/quorum.go for creating, serializing, verifying, and aggregating quorum certificates.
• Implements BLS signing/verifying in simplex/bls.go and corresponding unit tests in simplex/bls_test.go.

Reviewed Changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
simplex/test_util.go	Mock ValidatorInfo and newEngineConfig helper for tests
simplex/quorum.go	QC implementation, bytes/deserialize logic, and signature aggregator
simplex/config.go	Defines Config and SimplexChainContext
simplex/bls.go	BLSSigner/BLSVerifier and message encoding for BLS auth
simplex/bls_test.go	Unit tests for signing, verification, and QC aggregation
go.mod	Adds github.com/ava-labs/simplex dependency

Comments suppressed due to low confidence (4)

simplex/bls_test.go:97

• This test is empty; implement the scenario for when a QC has a signer not in the membership set or remove the placeholder.

func TestQCSignerNotInMembershipSet(t *testing.T) {

simplex/bls_test.go:101

• This test is empty; implement the scenario for when deserialization or verification is attempted on a certificate outside the membership set or remove the placeholder.

func TestQCNotInMembershipSet(t *testing.T) {

simplex/bls.go:75

• The comment refers to networkID and a length prefix that don't match the ASN.1 encoding of encodedSimplexSignedPayload. Update the docstring to reflect the actual fields and format produced by asn1.Marshal.

// encodesMessageToSign returns a byte slice [simplexLabel][chainID][networkID][message length][message].

simplex/quorum.go:90

• Iterating with for range quorumSize over an integer is invalid. Use a standard index loop: for i := 0; i < int(quorumSize); i++ {.

for range quorumSize {

[yacovm]

can we try renaming via git mv ?

[yacovm]

generally LGTM, but can we use git mv ?