// checkProofOfWork ensures the block header bits which indicate the target
// difficulty is in min/max range and that the block hash is less than the
// target difficulty as claimed.
//
// The flags modify the behavior of this function as follows:
// - BFNoPoWCheck: The check to ensure the block hash is less than the target
// difficulty is not performed.
func checkProofOfWork(header *wire.BlockHeader, powLimit *big.Int, flags BehaviorFlags) error {
// The target difficulty must be larger than zero.
target := CompactToBig(header.Bits)
if target.Sign() <= 0 {
str := fmt.Sprintf("block target difficulty of %064x is too low",
target)
return ruleError(ErrUnexpectedDifficulty, str)
}
// The target difficulty must be less than the maximum allowed.
if target.Cmp(powLimit) > 0 {
str := fmt.Sprintf("block target difficulty of %064x is "+
"higher than max of %064x", target, powLimit)
return ruleError(ErrUnexpectedDifficulty, str)
}
// The block hash must be less than the claimed target unless the flag
// to avoid proof of work checks is set.
if flags&BFNoPoWCheck != BFNoPoWCheck {
// The block hash must be less than the claimed target.
hash := header.BlockSha()
hashNum := ShaHashToBig(&hash)
if hashNum.Cmp(target) > 0 {
str := fmt.Sprintf("block hash of %064x is higher than "+
"expected max of %064x", hashNum, target)
return ruleError(ErrHighHash, str)
}
}
return nil
}
// FetchBlockHeaderBySha - return a ShaHash
func (db *LevelDb) FetchBlockHeaderBySha(sha *wire.ShaHash) (bh *wire.BlockHeader, err error) {
db.dbLock.Lock()
defer db.dbLock.Unlock()
// Read the raw block from the database.
buf, _, err := db.fetchSha(sha)
if err != nil {
return nil, err
}
// Only deserialize the header portion and ensure the transaction count
// is zero since this is a standalone header.
var blockHeader wire.BlockHeader
err = blockHeader.Deserialize(bytes.NewReader(buf))
if err != nil {
return nil, err
}
bh = &blockHeader
return bh, err
}
// TestBlockHeaderWire tests the BlockHeader wire encode and decode for various
// protocol versions.
func TestBlockHeaderWire(t *testing.T) {
nonce := uint32(123123) // 0x1e0f3
pver := uint32(70001)
// baseBlockHdr is used in the various tests as a baseline BlockHeader.
bits := uint32(0x1d00ffff)
baseBlockHdr := &wire.BlockHeader{
Version: 1,
PrevBlock: mainNetGenesisHash,
MerkleRoot: mainNetGenesisMerkleRoot,
Timestamp: time.Unix(0x495fab29, 0), // 2009-01-03 12:15:05 -0600 CST
Bits: bits,
Nonce: nonce,
}
// baseBlockHdrEncoded is the wire encoded bytes of baseBlockHdr.
baseBlockHdrEncoded := []byte{
0x01, 0x00, 0x00, 0x00, // Version 1
0x6f, 0xe2, 0x8c, 0x0a, 0xb6, 0xf1, 0xb3, 0x72,
0xc1, 0xa6, 0xa2, 0x46, 0xae, 0x63, 0xf7, 0x4f,
0x93, 0x1e, 0x83, 0x65, 0xe1, 0x5a, 0x08, 0x9c,
0x68, 0xd6, 0x19, 0x00, 0x00, 0x00, 0x00, 0x00, // PrevBlock
0x3b, 0xa3, 0xed, 0xfd, 0x7a, 0x7b, 0x12, 0xb2,
0x7a, 0xc7, 0x2c, 0x3e, 0x67, 0x76, 0x8f, 0x61,
0x7f, 0xc8, 0x1b, 0xc3, 0x88, 0x8a, 0x51, 0x32,
0x3a, 0x9f, 0xb8, 0xaa, 0x4b, 0x1e, 0x5e, 0x4a, // MerkleRoot
0x29, 0xab, 0x5f, 0x49, // Timestamp
0xff, 0xff, 0x00, 0x1d, // Bits
0xf3, 0xe0, 0x01, 0x00, // Nonce
}
tests := []struct {
in *wire.BlockHeader // Data to encode
out *wire.BlockHeader // Expected decoded data
buf []byte // Wire encoding
pver uint32 // Protocol version for wire encoding
}{
// Latest protocol version.
{
baseBlockHdr,
baseBlockHdr,
baseBlockHdrEncoded,
wire.ProtocolVersion,
},
// Protocol version BIP0035Version.
{
baseBlockHdr,
baseBlockHdr,
baseBlockHdrEncoded,
wire.BIP0035Version,
},
// Protocol version BIP0031Version.
{
baseBlockHdr,
baseBlockHdr,
baseBlockHdrEncoded,
wire.BIP0031Version,
},
// Protocol version NetAddressTimeVersion.
{
baseBlockHdr,
baseBlockHdr,
baseBlockHdrEncoded,
wire.NetAddressTimeVersion,
},
// Protocol version MultipleAddressVersion.
{
baseBlockHdr,
baseBlockHdr,
baseBlockHdrEncoded,
wire.MultipleAddressVersion,
},
}
t.Logf("Running %d tests", len(tests))
for i, test := range tests {
// Encode to wire format.
var buf bytes.Buffer
err := wire.TstWriteBlockHeader(&buf, test.pver, test.in)
if err != nil {
t.Errorf("writeBlockHeader #%d error %v", i, err)
continue
}
if !bytes.Equal(buf.Bytes(), test.buf) {
t.Errorf("writeBlockHeader #%d\n got: %s want: %s", i,
spew.Sdump(buf.Bytes()), spew.Sdump(test.buf))
continue
}
buf.Reset()
err = test.in.BtcEncode(&buf, pver)
if err != nil {
t.Errorf("BtcEncode #%d error %v", i, err)
continue
}
if !bytes.Equal(buf.Bytes(), test.buf) {
t.Errorf("BtcEncode #%d\n got: %s want: %s", i,
spew.Sdump(buf.Bytes()), spew.Sdump(test.buf))
continue
}
// Decode the block header from wire format.
var bh wire.BlockHeader
rbuf := bytes.NewReader(test.buf)
err = wire.TstReadBlockHeader(rbuf, test.pver, &bh)
if err != nil {
t.Errorf("readBlockHeader #%d error %v", i, err)
continue
}
if !reflect.DeepEqual(&bh, test.out) {
t.Errorf("readBlockHeader #%d\n got: %s want: %s", i,
spew.Sdump(&bh), spew.Sdump(test.out))
continue
}
rbuf = bytes.NewReader(test.buf)
err = bh.BtcDecode(rbuf, pver)
if err != nil {
t.Errorf("BtcDecode #%d error %v", i, err)
continue
}
if !reflect.DeepEqual(&bh, test.out) {
t.Errorf("BtcDecode #%d\n got: %s want: %s", i,
spew.Sdump(&bh), spew.Sdump(test.out))
continue
}
}
}
// TestBlockHeaderSerialize tests BlockHeader serialize and deserialize.
func TestBlockHeaderSerialize(t *testing.T) {
nonce := uint32(123123) // 0x1e0f3
// baseBlockHdr is used in the various tests as a baseline BlockHeader.
bits := uint32(0x1d00ffff)
baseBlockHdr := &wire.BlockHeader{
Version: 1,
PrevBlock: mainNetGenesisHash,
MerkleRoot: mainNetGenesisMerkleRoot,
Timestamp: time.Unix(0x495fab29, 0), // 2009-01-03 12:15:05 -0600 CST
Bits: bits,
Nonce: nonce,
}
// baseBlockHdrEncoded is the wire encoded bytes of baseBlockHdr.
baseBlockHdrEncoded := []byte{
0x01, 0x00, 0x00, 0x00, // Version 1
0x6f, 0xe2, 0x8c, 0x0a, 0xb6, 0xf1, 0xb3, 0x72,
0xc1, 0xa6, 0xa2, 0x46, 0xae, 0x63, 0xf7, 0x4f,
0x93, 0x1e, 0x83, 0x65, 0xe1, 0x5a, 0x08, 0x9c,
0x68, 0xd6, 0x19, 0x00, 0x00, 0x00, 0x00, 0x00, // PrevBlock
0x3b, 0xa3, 0xed, 0xfd, 0x7a, 0x7b, 0x12, 0xb2,
0x7a, 0xc7, 0x2c, 0x3e, 0x67, 0x76, 0x8f, 0x61,
0x7f, 0xc8, 0x1b, 0xc3, 0x88, 0x8a, 0x51, 0x32,
0x3a, 0x9f, 0xb8, 0xaa, 0x4b, 0x1e, 0x5e, 0x4a, // MerkleRoot
0x29, 0xab, 0x5f, 0x49, // Timestamp
0xff, 0xff, 0x00, 0x1d, // Bits
0xf3, 0xe0, 0x01, 0x00, // Nonce
}
tests := []struct {
in *wire.BlockHeader // Data to encode
out *wire.BlockHeader // Expected decoded data
buf []byte // Serialized data
}{
{
baseBlockHdr,
baseBlockHdr,
baseBlockHdrEncoded,
},
}
t.Logf("Running %d tests", len(tests))
for i, test := range tests {
// Serialize the block header.
var buf bytes.Buffer
err := test.in.Serialize(&buf)
if err != nil {
t.Errorf("Serialize #%d error %v", i, err)
continue
}
if !bytes.Equal(buf.Bytes(), test.buf) {
t.Errorf("Serialize #%d\n got: %s want: %s", i,
spew.Sdump(buf.Bytes()), spew.Sdump(test.buf))
continue
}
// Deserialize the block header.
var bh wire.BlockHeader
rbuf := bytes.NewReader(test.buf)
err = bh.Deserialize(rbuf)
if err != nil {
t.Errorf("Deserialize #%d error %v", i, err)
continue
}
if !reflect.DeepEqual(&bh, test.out) {
t.Errorf("Deserialize #%d\n got: %s want: %s", i,
spew.Sdump(&bh), spew.Sdump(test.out))
continue
}
}
}
func Test_dupTx(t *testing.T) {
// Ignore db remove errors since it means we didn't have an old one.
dbname := fmt.Sprintf("tstdbdup0")
dbnamever := dbname + ".ver"
_ = os.RemoveAll(dbname)
_ = os.RemoveAll(dbnamever)
db, err := database.CreateDB("leveldb", dbname)
if err != nil {
t.Errorf("Failed to open test database %v", err)
return
}
defer os.RemoveAll(dbname)
defer os.RemoveAll(dbnamever)
defer func() {
if err := db.Close(); err != nil {
t.Errorf("Close: unexpected error: %v", err)
}
}()
testdatafile := filepath.Join("testdata", "blocks1-256.bz2")
blocks, err := loadBlocks(t, testdatafile)
if err != nil {
t.Errorf("Unable to load blocks from test data for: %v",
err)
return
}
var lastSha *wire.ShaHash
// Populate with the fisrt 256 blocks, so we have blocks to 'mess with'
err = nil
out:
for height := int32(0); height < int32(len(blocks)); height++ {
block := blocks[height]
// except for NoVerify which does not allow lookups check inputs
mblock := block.MsgBlock()
var txneededList []*wire.ShaHash
for _, tx := range mblock.Transactions {
for _, txin := range tx.TxIn {
if txin.PreviousOutPoint.Index == uint32(4294967295) {
continue
}
origintxsha := &txin.PreviousOutPoint.Hash
txneededList = append(txneededList, origintxsha)
exists, err := db.ExistsTxSha(origintxsha)
if err != nil {
t.Errorf("ExistsTxSha: unexpected error %v ", err)
}
if !exists {
t.Errorf("referenced tx not found %v ", origintxsha)
}
_, err = db.FetchTxBySha(origintxsha)
if err != nil {
t.Errorf("referenced tx not found %v err %v ", origintxsha, err)
}
}
}
txlist := db.FetchUnSpentTxByShaList(txneededList)
for _, txe := range txlist {
if txe.Err != nil {
t.Errorf("tx list fetch failed %v err %v ", txe.Sha, txe.Err)
break out
}
}
newheight, err := db.InsertBlock(block)
if err != nil {
t.Errorf("failed to insert block %v err %v", height, err)
break out
}
if newheight != height {
t.Errorf("height mismatch expect %v returned %v", height, newheight)
break out
}
newSha, blkid, err := db.NewestSha()
if err != nil {
t.Errorf("failed to obtain latest sha %v %v", height, err)
}
if blkid != height {
t.Errorf("height doe not match latest block height %v %v %v", blkid, height, err)
}
blkSha := block.Sha()
if *newSha != *blkSha {
t.Errorf("Newest block sha does not match freshly inserted one %v %v %v ", newSha, blkSha, err)
}
lastSha = blkSha
}
// generate a new block based on the last sha
// these block are not verified, so there are a bunch of garbage fields
// in the 'generated' block.
var bh wire.BlockHeader
bh.Version = 2
bh.PrevBlock = *lastSha
// Bits, Nonce are not filled in
mblk := wire.NewMsgBlock(&bh)
hash, _ := wire.NewShaHashFromStr("df2b060fa2e5e9c8ed5eaf6a45c13753ec8c63282b2688322eba40cd98ea067a")
po := wire.NewOutPoint(hash, 0)
txI := wire.NewTxIn(po, []byte("garbage"))
txO := wire.NewTxOut(50000000, []byte("garbageout"))
var tx wire.MsgTx
tx.AddTxIn(txI)
tx.AddTxOut(txO)
mblk.AddTransaction(&tx)
blk := btcutil.NewBlock(mblk)
fetchList := []*wire.ShaHash{hash}
listReply := db.FetchUnSpentTxByShaList(fetchList)
for _, lr := range listReply {
if lr.Err != nil {
t.Errorf("sha %v spent %v err %v\n", lr.Sha,
lr.TxSpent, lr.Err)
}
}
_, err = db.InsertBlock(blk)
if err != nil {
t.Errorf("failed to insert phony block %v", err)
}
// ok, did it 'spend' the tx ?
listReply = db.FetchUnSpentTxByShaList(fetchList)
for _, lr := range listReply {
if lr.Err != database.ErrTxShaMissing {
t.Errorf("sha %v spent %v err %v\n", lr.Sha,
lr.TxSpent, lr.Err)
}
}
txlist := blk.Transactions()
for _, tx := range txlist {
txsha := tx.Sha()
txReply, err := db.FetchTxBySha(txsha)
if err != nil {
t.Errorf("fully spent lookup %v err %v\n", hash, err)
} else {
for _, lr := range txReply {
if lr.Err != nil {
t.Errorf("stx %v spent %v err %v\n", lr.Sha,
lr.TxSpent, lr.Err)
}
}
}
}
t.Logf("Dropping block")
err = db.DropAfterBlockBySha(lastSha)
if err != nil {
t.Errorf("failed to drop spending block %v", err)
}
}
// checkBlockHeaderContext peforms several validation checks on the block header
// which depend on its position within the block chain.
//
// The flags modify the behavior of this function as follows:
// - BFFastAdd: All checks except those involving comparing the header against
// the checkpoints are not performed.
func (b *BlockChain) checkBlockHeaderContext(header *wire.BlockHeader, prevNode *blockNode, flags BehaviorFlags) error {
// The genesis block is valid by definition.
if prevNode == nil {
return nil
}
fastAdd := flags&BFFastAdd == BFFastAdd
if !fastAdd {
// Ensure the difficulty specified in the block header matches
// the calculated difficulty based on the previous block and
// difficulty retarget rules.
expectedDifficulty, err := b.calcNextRequiredDifficulty(prevNode,
header.Timestamp)
if err != nil {
return err
}
blockDifficulty := header.Bits
if blockDifficulty != expectedDifficulty {
str := "block difficulty of %d is not the expected value of %d"
str = fmt.Sprintf(str, blockDifficulty, expectedDifficulty)
return ruleError(ErrUnexpectedDifficulty, str)
}
// Ensure the timestamp for the block header is after the
// median time of the last several blocks (medianTimeBlocks).
medianTime, err := b.calcPastMedianTime(prevNode)
if err != nil {
log.Errorf("calcPastMedianTime: %v", err)
return err
}
if !header.Timestamp.After(medianTime) {
str := "block timestamp of %v is not after expected %v"
str = fmt.Sprintf(str, header.Timestamp, medianTime)
return ruleError(ErrTimeTooOld, str)
}
}
// The height of this block is one more than the referenced previous
// block.
blockHeight := prevNode.height + 1
// Ensure chain matches up to predetermined checkpoints.
blockHash := header.BlockSha()
if !b.verifyCheckpoint(blockHeight, &blockHash) {
str := fmt.Sprintf("block at height %d does not match "+
"checkpoint hash", blockHeight)
return ruleError(ErrBadCheckpoint, str)
}
// Find the previous checkpoint and prevent blocks which fork the main
// chain before it. This prevents storage of new, otherwise valid,
// blocks which build off of old blocks that are likely at a much easier
// difficulty and therefore could be used to waste cache and disk space.
checkpointBlock, err := b.findPreviousCheckpoint()
if err != nil {
return err
}
if checkpointBlock != nil && blockHeight < checkpointBlock.Height() {
str := fmt.Sprintf("block at height %d forks the main chain "+
"before the previous checkpoint at height %d",
blockHeight, checkpointBlock.Height())
return ruleError(ErrForkTooOld, str)
}
if !fastAdd {
// Reject version 2 blocks once a majority of the network has
// upgraded. This is part of BIP0066.
if header.Version < 3 && b.isMajorityVersion(3, prevNode,
b.chainParams.BlockRejectNumRequired) {
str := "new blocks with version %d are no longer valid"
str = fmt.Sprintf(str, header.Version)
return ruleError(ErrBlockVersionTooOld, str)
}
// Reject version 1 blocks once a majority of the network has
// upgraded. This is part of BIP0034.
if header.Version < 2 && b.isMajorityVersion(2, prevNode,
b.chainParams.BlockRejectNumRequired) {
str := "new blocks with version %d are no longer valid"
str = fmt.Sprintf(str, header.Version)
return ruleError(ErrBlockVersionTooOld, str)
}
}
return nil
}
