ExtraData field added to block

blockchain/block.go

@@ -9,10 +9,9 @@ import (
 )
 
 const (
-	// BlockSize is the maximum size of a block in bytes when marshaled (about 250K).
-	BlockSize = 1 << 18
-	// BlockHeaderLen is the length in bytes of a block header.
-	BlockHeaderLen = 2*(32/8) + 64/8 + 2*HashLen
+	// MaxBlockSize is the maximum size of a block in bytes when marshaled
+	// (about 250K).
+	MaxBlockSize = 1 << 18
 )
 
 // BlockHeader contains metadata about a block
@@ -28,6 +27,9 @@ type BlockHeader struct {
 	Time uint32
 	// Nonce starts at 0 and increments by 1 for every hash when mining
 	Nonce uint64
+	// ExtraData is an extra field that can be filled with arbitrary data to
+	// be stored in the block
+	ExtraData []byte
 }
 
 // Marshal converts a BlockHeader to a byte slice
@@ -48,10 +50,18 @@ func (bh *BlockHeader) Marshal() []byte {
 	buf = append(buf, bh.Target.Marshal()...)
 	buf = append(buf, tempBufTime...)
 	buf = append(buf, tempBufNonce...)
+	buf = append(buf, bh.ExtraData...)
 
 	return buf
 }
 
+// Len returns the length in bytes of the BlockHeader.
+func (bh *BlockHeader) Len() int {
+	l := 2*(32/8) + 64/8 + 2*HashLen
+	l += len(bh.ExtraData)
+	return l
+}
+
 // Block represents a block in the blockchain. Contains transactions and header metadata.
 type Block struct {
 	BlockHeader
@@ -60,7 +70,7 @@ type Block struct {
 
 // Len returns the length in bytes of the Block.
 func (b *Block) Len() int {
-	l := BlockHeaderLen
+	l := b.BlockHeader.Len()
 	for _, t := range b.Transactions {
 		l += t.Len()
 	}

blockchain/block_test.go

@@ -3,6 +3,7 @@ package blockchain
 import (
 	"bytes"
 	"testing"
+	"time"
 )
 
 func TestEncodeDecodeBlock(t *testing.T) {
@@ -25,3 +26,35 @@ func TestContainsTransaction(t *testing.T) {
 		t.Fail()
 	}
 }
+
+func TestBlockHeaderLen(t *testing.T) {
+	bh := &BlockHeader{
+		0,
+		NewHash(),
+		NewValidTarget(),
+		uint32(time.Now().Unix()),
+		0,
+		[]byte{0x00, 0x01, 0x02},
+	}
+
+	len := 2*(32/8) + 64/8 + 2*HashLen + 3
+
+	if bh.Len() != len {
+		t.Fail()
+	}
+
+	bh = &BlockHeader{
+		0,
+		NewHash(),
+		NewValidTarget(),
+		uint32(time.Now().Unix()),
+		0,
+		[]byte{},
+	}
+
+	len = 2*(32/8) + 64/8 + 2*HashLen
+
+	if bh.Len() != len {
+		t.Fail()
+	}
+}

blockchain/genesis.go

@@ -11,7 +11,7 @@ import (
 // 	- LastBlock = 0
 // 	- There is only one transaction in the block, the CloudBase transaction that
 // 	  awards the miner with the block reward.
-func Genesis(miner Address, target Hash, blockReward uint64) *Block {
+func Genesis(miner Address, target Hash, blockReward uint64, extraData []byte) *Block {
 
 	cbReward := TxOutput{
 		Amount:    blockReward,
@@ -38,6 +38,7 @@ func Genesis(miner Address, target Hash, blockReward uint64) *Block {
 			Target:      target,
 			Time:        uint32(time.Now().Unix()),
 			Nonce:       0,
+			ExtraData:   extraData,
 		},
 		Transactions: []*Transaction{cbTx},
 	}

blockchain/genesis_test.go

@@ -9,7 +9,7 @@ func TestGenesis(t *testing.T) {
 	miner := NewWallet()
 	currentTarget := BigIntToHash(MaxTarget)
 	currentBlockReward := uint64(25)
-	gb := Genesis(miner.Public(), currentTarget, currentBlockReward)
+	gb := Genesis(miner.Public(), currentTarget, currentBlockReward, []byte{})
 
 	// Check if the genesis block is equal to nil
 	if gb == nil {

blockchain/validation.go

@@ -73,8 +73,11 @@ const (
 	BadGenesisBlockNumber
 	// BadGenesisTarget is returned when the genesis block's target is invalid.
 	BadGenesisTarget
-	// BadGenesisTime is returned when teh gensis block's time is invalid.
+	// BadGenesisTime is returned when the gensis block's time is invalid.
 	BadGenesisTime
+	// BadGenesisBlockSize is returned when the size of the block exceeds the
+	// maximum block size
+	BadGenesisBlockSize
 	// NilGenesisBlock is returned when the genesis block is equal to nil.
 	NilGenesisBlock
 )
@@ -104,6 +107,9 @@ const (
 	// BadGenesisBlock is returned if the block is a genesis block and is
 	// invalid.
 	BadGenesisBlock
+	// BadBlockSize is returned when the size of the block exceeds the maximum
+	// block size
+	BadBlockSize
 	// NilBlock is returned when the block pointer is nil.
 	NilBlock
 )
@@ -190,11 +196,17 @@ func ValidCloudBase(t *Transaction) (bool, CloudBaseTransactionCode) {
 
 // ValidGenesisBlock checks whether a block is a valid genesis block.
 func (bc *BlockChain) ValidGenesisBlock(gb *Block) (bool, GenesisBlockCode) {
+
 	// Check if the genesis block is equal to nil.
 	if gb == nil {
 		return false, NilGenesisBlock
 	}
 
+	// Check if the genesis block is too large.
+	if gb.Len() > MaxBlockSize {
+		return false, BadGenesisBlockSize
+	}
+
 	// Check if the genesis block's block number is equal to 0.
 	if gb.BlockHeader.BlockNumber != 0 ||
 		bc.Blocks[0] != gb {
@@ -234,12 +246,17 @@ func (bc *BlockChain) ValidGenesisBlock(gb *Block) (bool, GenesisBlockCode) {
 // ValidBlock checks whether a block is valid.
 func (bc *BlockChain) ValidBlock(b *Block) (bool, BlockCode) {
 
-	// Check if the block is equal to nil
+	// Check if the block is equal to nil.
 	if b == nil {
 		return false, NilBlock
 	}
 
-	// Check if the block is the genesis block
+	// Check if the block is too large.
+	if b.Len() > MaxBlockSize {
+		return false, BadBlockSize
+	}
+
+	// Check if the block is the genesis block.
 	if b.BlockHeader.BlockNumber == 0 || bc.Blocks[0] == b {
 		if valid, code := bc.ValidGenesisBlock(b); !valid {
 			log.Errorf("Invalid GenesisBlock, GenesisBlockCode: %d", code)

blockchain/validation_test.go

@@ -111,11 +111,34 @@ func TestValidBlockNilBlock(t *testing.T) {
 	}
 }
 
+func TestValidBlockBadBlockSize(t *testing.T) {
+	bc, b := NewValidChainAndBlock()
+
+	for i := 0; i <= MaxBlockSize/TxOutputLen; i++ {
+		b.Transactions[0].Outputs = append(
+			b.Transactions[0].Outputs,
+			TxOutput{
+				0,
+				NewWallet().Public(),
+			},
+		)
+	}
+
+	valid, code := bc.ValidBlock(b)
+
+	if valid {
+		t.Fail()
+	}
+	if code != BadBlockSize {
+		t.Fail()
+	}
+}
+
 func TestValidBlockBadGenesisBlock(t *testing.T) {
 	miner := NewWallet()
 	currentTarget := BigIntToHash(MaxTarget)
 	currentBlockReward := uint64(25)
-	gb := Genesis(miner.Public(), currentTarget, currentBlockReward)
+	gb := Genesis(miner.Public(), currentTarget, currentBlockReward, []byte{})
 	gb.Target = BigIntToHash(BigExp(2, 255))
 	bc := &BlockChain{
 		Blocks: []*Block{gb},
@@ -407,7 +430,7 @@ func TestValidGenesisBlock(t *testing.T) {
 	miner := NewWallet()
 	currentTarget := BigIntToHash(MaxTarget)
 	currentBlockReward := uint64(25)
-	gb := Genesis(miner.Public(), currentTarget, currentBlockReward)
+	gb := Genesis(miner.Public(), currentTarget, currentBlockReward, []byte{})
 	bc := &BlockChain{
 		Blocks: []*Block{gb},
 		Head:   HashSum(gb),
@@ -442,11 +465,43 @@ func TestValidGenesisBlockNilGenesisBlock(t *testing.T) {
 	}
 }
 
+func TestValidGenesisBlockBadGenesisBlockSize(t *testing.T) {
+	miner := NewWallet()
+	currentTarget := BigIntToHash(MaxTarget)
+	currentBlockReward := uint64(25)
+	gb := Genesis(miner.Public(), currentTarget, currentBlockReward, []byte{})
+
+	for i := 0; i <= MaxBlockSize/TxOutputLen; i++ {
+		gb.Transactions[0].Outputs = append(
+			gb.Transactions[0].Outputs,
+			TxOutput{
+				0,
+				NewWallet().Public(),
+			},
+		)
+	}
+
+	bc := &BlockChain{
+		Blocks: []*Block{gb},
+		Head:   HashSum(gb),
+	}
+
+	valid, code := bc.ValidGenesisBlock(gb)
+
+	if valid {
+		t.Fail()
+	}
+
+	if code != BadGenesisBlockSize {
+		t.Fail()
+	}
+}
+
 func TestValidGenesisBlockBadGenesisBlockNumber(t *testing.T) {
 	miner := NewWallet()
 	currentTarget := BigIntToHash(MaxTarget)
 	currentBlockReward := uint64(25)
-	gb := Genesis(miner.Public(), currentTarget, currentBlockReward)
+	gb := Genesis(miner.Public(), currentTarget, currentBlockReward, []byte{})
 	gb.BlockHeader.BlockNumber = 1
 	bc := &BlockChain{
 		Blocks: []*Block{gb},
@@ -484,7 +539,7 @@ func TestValidGenesisBlockBadGenesisLastBlock(t *testing.T) {
 	miner := NewWallet()
 	currentTarget := BigIntToHash(MaxTarget)
 	currentBlockReward := uint64(25)
-	gb := Genesis(miner.Public(), currentTarget, currentBlockReward)
+	gb := Genesis(miner.Public(), currentTarget, currentBlockReward, []byte{})
 	gb.LastBlock = NewHash()
 	bc := &BlockChain{
 		Blocks: []*Block{gb},
@@ -506,7 +561,7 @@ func TestValidGenesisBlockBadGenesisTransactions(t *testing.T) {
 	miner := NewWallet()
 	currentTarget := BigIntToHash(MaxTarget)
 	currentBlockReward := uint64(25)
-	gb := Genesis(miner.Public(), currentTarget, currentBlockReward)
+	gb := Genesis(miner.Public(), currentTarget, currentBlockReward, []byte{})
 	gb.Transactions = append(gb.Transactions, NewTransaction())
 	bc := &BlockChain{
 		Blocks: []*Block{gb},
@@ -528,7 +583,7 @@ func TestValidGenesisBlockBadGenesisCloudBaseTransaction(t *testing.T) {
 	miner := NewWallet()
 	currentTarget := BigIntToHash(MaxTarget)
 	currentBlockReward := uint64(25)
-	gb := Genesis(miner.Public(), currentTarget, currentBlockReward)
+	gb := Genesis(miner.Public(), currentTarget, currentBlockReward, []byte{})
 	gb.Transactions[0] = NewTransaction()
 	bc := &BlockChain{
 		Blocks: []*Block{gb},
@@ -550,7 +605,7 @@ func TestValidGenesisBlockBadGenesisTarget(t *testing.T) {
 	miner := NewWallet()
 	currentTarget := BigIntToHash(MaxTarget)
 	currentBlockReward := uint64(25)
-	gb := Genesis(miner.Public(), currentTarget, currentBlockReward)
+	gb := Genesis(miner.Public(), currentTarget, currentBlockReward, []byte{})
 	gb.Target = BigIntToHash(BigExp(2, 255))
 	bc := &BlockChain{
 		Blocks: []*Block{gb},
@@ -572,7 +627,7 @@ func TestValidGenesisBlockBadGenesisTime(t *testing.T) {
 	miner := NewWallet()
 	currentTarget := BigIntToHash(MaxTarget)
 	currentBlockReward := uint64(25)
-	gb := Genesis(miner.Public(), currentTarget, currentBlockReward)
+	gb := Genesis(miner.Public(), currentTarget, currentBlockReward, []byte{})
 	gb.Time = 0
 	bc := &BlockChain{
 		Blocks: []*Block{gb},