header: verify aggregator hash against validators (cosmos#845)

Fixes cosmos#833

node/full_client_test.go

@@ -56,14 +56,15 @@ func getRandomValidatorSet() *tmtypes.ValidatorSet {
 	}
 }
 
+var genesisValidatorKey = ed25519.GenPrivKey()
+
 // TODO: use n and return n validators
 func getGenesisValidatorSetWithSigner(n int) ([]tmtypes.GenesisValidator, crypto.PrivKey) {
-	validatorKey := ed25519.GenPrivKey()
 	nodeKey := &p2p.NodeKey{
-		PrivKey: validatorKey,
+		PrivKey: genesisValidatorKey,
 	}
 	signingKey, _ := conv.GetNodeKey(nodeKey)
-	pubKey := validatorKey.PubKey()
+	pubKey := genesisValidatorKey.PubKey()
 
 	genesisValidators := []tmtypes.GenesisValidator{
 		{Address: pubKey.Address(), PubKey: pubKey, Power: int64(100), Name: "gen #1"},

state/executor.go

@@ -290,6 +290,10 @@ func (e *BlockExecutor) validate(state types.State, block *types.Block) error {
 		return errors.New("LastResultsHash mismatch")
 	}
 
+	if !bytes.Equal(block.SignedHeader.Header.AggregatorsHash[:], state.Validators.Hash()) {
+		return errors.New("AggregatorsHash mismatch")
+	}
+
 	return nil
 }