core/parsigdb: gate hash tree root keying behind feature flag

app/featureset/featureset.go

@@ -45,6 +45,11 @@ const (
  // The feature gets automatically enabled when the current network is gnosis|chiado,
  // unless the user disabled this feature explicitly.
  GnosisBlockHotfix Feature = "gnosis_block_hotfix"
+
+ // HardenedParSigDB enables keying ParSigDB elements with their hash tree root
+ // on top of the core.Duty object.
+ // Since this is a breaking change, we'll gradually enable it in later releases.
+ HardenedParSigDB Feature = "hardened_par_sig_db"
 )
 
 var (

core/parsigdb/memory.go

@@ -9,6 +9,7 @@ import (
  "sync"
 
  "github.com/obolnetwork/charon/app/errors"
+ "github.com/obolnetwork/charon/app/featureset"
  "github.com/obolnetwork/charon/app/log"
  "github.com/obolnetwork/charon/app/z"
  "github.com/obolnetwork/charon/core"
@@ -236,6 +237,10 @@ func getThresholdMatching(typ core.DutyType, sigs []core.ParSignedData, threshol
 // rootFromParSigDataSet returns the MessageRoot of data only if the duty is supported,
 // and only if data is not a core.Signature.
 func rootFromParSigDataSet(duty core.Duty, data core.ParSignedData) ([32]byte, error) {
+ if !featureset.Enabled(featureset.HardenedParSigDB) {
+ return [32]byte{}, nil
+ }
+
  // known limitation: sync message and contributions might have different hashes,
  // ignore them for now.
  // signature duties don't have a MessageRoot implementation at all, by design.