chg: dev: errMismatchingSprintValidators

consensus/bor/bor.go

@@ -429,8 +429,9 @@ func (c *Bor) verifyCascadingFields(chain consensus.ChainReader, header *types.H
 		return err
 	}
 
-	// If the block is a sprint end block, verify the validator list
-	if number%c.config.Sprint == 0 {
+	isSprintEnd := (number+1)%c.config.Sprint == 0
+	// verify the validator list in the last sprint block
+	if isSprintEnd {
 		validatorsBytes := make([]byte, len(snap.ValidatorSet.Validators)*validatorHeaderBytesLength)
 
 		currentValidators := snap.ValidatorSet.Copy().Validators
@@ -439,6 +440,10 @@ func (c *Bor) verifyCascadingFields(chain consensus.ChainReader, header *types.H
 		for i, validator := range currentValidators {
 			copy(validatorsBytes[i*validatorHeaderBytesLength:], validator.HeaderBytes())
 		}
+		// len(header.Extra) >= extraVanity+extraSeal has already been validated in validateHeaderExtraField, so this won't result in a panic
+		if !bytes.Equal(header.Extra[extraVanity : len(header.Extra)-extraSeal], validatorsBytes) {
+			return errMismatchingSprintValidators
+		}
 	}
 
 	// All basic checks passed, verify the seal and return
@@ -474,7 +479,7 @@ func (c *Bor) snapshot(chain consensus.ChainReader, number uint64, hash common.H
 		// up more headers than allowed to be reorged (chain reinit from a freezer),
 		// consider the checkpoint trusted and snapshot it.
 		// TODO fix this
-		if number == 0 /* || (number%c.config.Sprint == 0 && (len(headers) > params.ImmutabilityThreshold || chain.GetHeaderByNumber(number-1) == nil)) */ {
+		if number == 0 {
 			checkpoint := chain.GetHeaderByNumber(number)
 			if checkpoint != nil {
 				// get checkpoint data

consensus/bor/bor_test/helper.go

@@ -105,7 +105,16 @@ func buildMinimalNextHeader(t *testing.T, block *types.Block, borConfig *params.
 	header.Number.Add(header.Number, big.NewInt(1))
 	header.ParentHash = block.Hash()
 	header.Time += bor.CalcProducerDelay(header.Number.Uint64(), borConfig.Period, borConfig.Sprint, borConfig.ProducerDelay)
-	header.Extra = make([]byte, 97) // vanity (32) + extraSeal (65)
+	isSprintEnd := (header.Number.Uint64()+1)%borConfig.Sprint == 0
+	if isSprintEnd {
+		header.Extra = make([]byte, 32 + 40 + 65) // vanity + validatorBytes + extraSeal
+		// the genesis file was initialized with a validator 0x71562b71999873db5b286df957af199ec94617f7 with power 10
+		// So, if you change ./genesis.json, do change the following as well
+		validatorBytes, _ := hex.DecodeString("71562b71999873db5b286df957af199ec94617f7000000000000000000000000000000000000000a")
+		copy(header.Extra[32:72], validatorBytes)
+	} else {
+		header.Extra = make([]byte, 32 + 65) // vanity + extraSeal
+	}
 	_key, _ := hex.DecodeString(privKey)
 	sig, err := secp256k1.Sign(crypto.Keccak256(bor.BorRLP(header)), _key)
 	if err != nil {