// TestMerkleBlockWire tests the MsgMerkleBlock wire encode and decode for
// various numbers of transaction hashes and protocol versions.
func TestMerkleBlockWire(t *testing.T) {
tests := []struct {
in *wire.MsgMerkleBlock // Message to encode
out *wire.MsgMerkleBlock // Expected decoded message
buf []byte // Wire encoding
pver uint32 // Protocol version for wire encoding
}{
// Latest protocol version.
{
&merkleBlockOne, &merkleBlockOne, merkleBlockOneBytes,
wire.ProtocolVersion,
},
// Protocol version BIP0037Version.
{
&merkleBlockOne, &merkleBlockOne, merkleBlockOneBytes,
wire.BIP0037Version,
},
}
t.Logf("Running %d tests", len(tests))
for i, test := range tests {
// Encode the message to wire format.
var buf bytes.Buffer
err := test.in.BtcEncode(&buf, test.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 message from wire format.
var msg wire.MsgMerkleBlock
rbuf := bytes.NewReader(test.buf)
err = msg.BtcDecode(rbuf, test.pver)
if err != nil {
t.Errorf("BtcDecode #%d error %v", i, err)
continue
}
if !reflect.DeepEqual(&msg, test.out) {
t.Errorf("BtcDecode #%d\n got: %s want: %s", i,
spew.Sdump(&msg), spew.Sdump(test.out))
continue
}
}
}
// TestMerkleBlockOverflowErrors performs tests to ensure encoding and decoding
// merkle blocks that are intentionally crafted to use large values for the
// number of hashes and flags are handled properly. This could otherwise
// potentially be used as an attack vector.
func TestMerkleBlockOverflowErrors(t *testing.T) {
// Use protocol version 70001 specifically here instead of the latest
// protocol version because the test data is using bytes encoded with
// that version.
pver := uint32(70001)
// Create bytes for a merkle block that claims to have more than the max
// allowed tx hashes.
var buf bytes.Buffer
wire.TstWriteVarInt(&buf, pver, wire.MaxTxPerBlock+1)
numHashesOffset := 84
exceedMaxHashes := make([]byte, numHashesOffset)
copy(exceedMaxHashes, merkleBlockOneBytes[:numHashesOffset])
exceedMaxHashes = append(exceedMaxHashes, buf.Bytes()...)
// Create bytes for a merkle block that claims to have more than the max
// allowed flag bytes.
buf.Reset()
wire.TstWriteVarInt(&buf, pver, wire.MaxFlagsPerMerkleBlock+1)
numFlagBytesOffset := 117
exceedMaxFlagBytes := make([]byte, numFlagBytesOffset)
copy(exceedMaxFlagBytes, merkleBlockOneBytes[:numFlagBytesOffset])
exceedMaxFlagBytes = append(exceedMaxFlagBytes, buf.Bytes()...)
tests := []struct {
buf []byte // Wire encoding
pver uint32 // Protocol version for wire encoding
err error // Expected error
}{
// Block that claims to have more than max allowed hashes.
{exceedMaxHashes, pver, &wire.MessageError{}},
// Block that claims to have more than max allowed flag bytes.
{exceedMaxFlagBytes, pver, &wire.MessageError{}},
}
t.Logf("Running %d tests", len(tests))
for i, test := range tests {
// Decode from wire format.
var msg wire.MsgMerkleBlock
r := bytes.NewReader(test.buf)
err := msg.BtcDecode(r, test.pver)
if reflect.TypeOf(err) != reflect.TypeOf(test.err) {
t.Errorf("BtcDecode #%d wrong error got: %v, want: %v",
i, err, reflect.TypeOf(test.err))
continue
}
}
}
// NewMerkleBlock returns a new *wire.MsgMerkleBlock and an array of the matched
// transaction index numbers based on the passed block and filter.
func NewMerkleBlock(block *btcutil.Block, filter *Filter) (*wire.MsgMerkleBlock, []uint32) {
numTx := uint32(len(block.Transactions()))
mBlock := merkleBlock{
numTx: numTx,
allHashes: make([]*chainhash.Hash, 0, numTx),
matchedBits: make([]byte, 0, numTx),
}
// Find and keep track of any transactions that match the filter.
var matchedIndices []uint32
for txIndex, tx := range block.Transactions() {
if filter.MatchTxAndUpdate(tx) {
mBlock.matchedBits = append(mBlock.matchedBits, 0x01)
matchedIndices = append(matchedIndices, uint32(txIndex))
} else {
mBlock.matchedBits = append(mBlock.matchedBits, 0x00)
}
mBlock.allHashes = append(mBlock.allHashes, tx.Hash())
}
// Calculate the number of merkle branches (height) in the tree.
height := uint32(0)
for mBlock.calcTreeWidth(height) > 1 {
height++
}
// Build the depth-first partial merkle tree.
mBlock.traverseAndBuild(height, 0)
// Create and return the merkle block.
msgMerkleBlock := wire.MsgMerkleBlock{
Header: block.MsgBlock().Header,
Transactions: mBlock.numTx,
Hashes: make([]*chainhash.Hash, 0, len(mBlock.finalHashes)),
Flags: make([]byte, (len(mBlock.bits)+7)/8),
}
for _, hash := range mBlock.finalHashes {
msgMerkleBlock.AddTxHash(hash)
}
for i := uint32(0); i < uint32(len(mBlock.bits)); i++ {
msgMerkleBlock.Flags[i/8] |= mBlock.bits[i] << (i % 8)
}
return &msgMerkleBlock, matchedIndices
}
// TestMerkleBlockWireErrors performs negative tests against wire encode and
// decode of MsgBlock to confirm error paths work correctly.
func TestMerkleBlockWireErrors(t *testing.T) {
// Use protocol version 70001 specifically here instead of the latest
// because the test data is using bytes encoded with that protocol
// version.
pver := uint32(70001)
pverNoMerkleBlock := wire.BIP0037Version - 1
wireErr := &wire.MessageError{}
tests := []struct {
in *wire.MsgMerkleBlock // Value to encode
buf []byte // Wire encoding
pver uint32 // Protocol version for wire encoding
max int // Max size of fixed buffer to induce errors
writeErr error // Expected write error
readErr error // Expected read error
}{
// Force error in version.
{
&merkleBlockOne, merkleBlockOneBytes, pver, 0,
io.ErrShortWrite, io.EOF,
},
// Force error in prev block hash.
{
&merkleBlockOne, merkleBlockOneBytes, pver, 4,
io.ErrShortWrite, io.EOF,
},
// Force error in merkle root.
{
&merkleBlockOne, merkleBlockOneBytes, pver, 36,
io.ErrShortWrite, io.EOF,
},
// Force error in timestamp.
{
&merkleBlockOne, merkleBlockOneBytes, pver, 68,
io.ErrShortWrite, io.EOF,
},
// Force error in difficulty bits.
{
&merkleBlockOne, merkleBlockOneBytes, pver, 72,
io.ErrShortWrite, io.EOF,
},
// Force error in header nonce.
{
&merkleBlockOne, merkleBlockOneBytes, pver, 76,
io.ErrShortWrite, io.EOF,
},
// Force error in transaction count.
{
&merkleBlockOne, merkleBlockOneBytes, pver, 80,
io.ErrShortWrite, io.EOF,
},
// Force error in num hashes.
{
&merkleBlockOne, merkleBlockOneBytes, pver, 84,
io.ErrShortWrite, io.EOF,
},
// Force error in hashes.
{
&merkleBlockOne, merkleBlockOneBytes, pver, 85,
io.ErrShortWrite, io.EOF,
},
// Force error in num flag bytes.
{
&merkleBlockOne, merkleBlockOneBytes, pver, 117,
io.ErrShortWrite, io.EOF,
},
// Force error in flag bytes.
{
&merkleBlockOne, merkleBlockOneBytes, pver, 118,
io.ErrShortWrite, io.EOF,
},
// Force error due to unsupported protocol version.
{
&merkleBlockOne, merkleBlockOneBytes, pverNoMerkleBlock,
119, wireErr, wireErr,
},
}
t.Logf("Running %d tests", len(tests))
for i, test := range tests {
// Encode to wire format.
w := newFixedWriter(test.max)
err := test.in.BtcEncode(w, test.pver)
if reflect.TypeOf(err) != reflect.TypeOf(test.writeErr) {
t.Errorf("BtcEncode #%d wrong error got: %v, want: %v",
i, err, test.writeErr)
continue
}
// For errors which are not of type wire.MessageError, check
// them for equality.
if _, ok := err.(*wire.MessageError); !ok {
if err != test.writeErr {
t.Errorf("BtcEncode #%d wrong error got: %v, "+
"want: %v", i, err, test.writeErr)
continue
}
}
// Decode from wire format.
var msg wire.MsgMerkleBlock
r := newFixedReader(test.max, test.buf)
err = msg.BtcDecode(r, test.pver)
if reflect.TypeOf(err) != reflect.TypeOf(test.readErr) {
t.Errorf("BtcDecode #%d wrong error got: %v, want: %v",
i, err, test.readErr)
continue
}
// For errors which are not of type wire.MessageError, check
// them for equality.
if _, ok := err.(*wire.MessageError); !ok {
if err != test.readErr {
t.Errorf("BtcDecode #%d wrong error got: %v, "+
"want: %v", i, err, test.readErr)
continue
}
}
}
}
// TestMerkleBlock tests the MsgMerkleBlock API.
func TestMerkleBlock(t *testing.T) {
pver := wire.ProtocolVersion
// Block 1 header.
prevHash := &blockOne.Header.PrevBlock
merkleHash := &blockOne.Header.MerkleRoot
bits := blockOne.Header.Bits
nonce := blockOne.Header.Nonce
bh := wire.NewBlockHeader(prevHash, merkleHash, bits, nonce)
// Ensure the command is expected value.
wantCmd := "merkleblock"
msg := wire.NewMsgMerkleBlock(bh)
if cmd := msg.Command(); cmd != wantCmd {
t.Errorf("NewMsgBlock: wrong command - got %v want %v",
cmd, wantCmd)
}
// Ensure max payload is expected value for latest protocol version.
// Num addresses (varInt) + max allowed addresses.
wantPayload := uint32(1000000)
maxPayload := msg.MaxPayloadLength(pver)
if maxPayload != wantPayload {
t.Errorf("MaxPayloadLength: wrong max payload length for "+
"protocol version %d - got %v, want %v", pver,
maxPayload, wantPayload)
}
// Load maxTxPerBlock hashes
data := make([]byte, 32)
for i := 0; i < wire.MaxTxPerBlock; i++ {
rand.Read(data)
hash, err := wire.NewShaHash(data)
if err != nil {
t.Errorf("NewShaHash failed: %v\n", err)
return
}
if err = msg.AddTxHash(hash); err != nil {
t.Errorf("AddTxHash failed: %v\n", err)
return
}
}
// Add one more Tx to test failure.
rand.Read(data)
hash, err := wire.NewShaHash(data)
if err != nil {
t.Errorf("NewShaHash failed: %v\n", err)
return
}
if err = msg.AddTxHash(hash); err == nil {
t.Errorf("AddTxHash succeeded when it should have failed")
return
}
// Test encode with latest protocol version.
var buf bytes.Buffer
err = msg.BtcEncode(&buf, pver)
if err != nil {
t.Errorf("encode of MsgMerkleBlock failed %v err <%v>", msg, err)
}
// Test decode with latest protocol version.
readmsg := wire.MsgMerkleBlock{}
err = readmsg.BtcDecode(&buf, pver)
if err != nil {
t.Errorf("decode of MsgMerkleBlock failed [%v] err <%v>", buf, err)
}
// Force extra hash to test maxTxPerBlock.
msg.Hashes = append(msg.Hashes, hash)
err = msg.BtcEncode(&buf, pver)
if err == nil {
t.Errorf("encode of MsgMerkleBlock succeeded with too many " +
"tx hashes when it should have failed")
return
}
// Force too many flag bytes to test maxFlagsPerMerkleBlock.
// Reset the number of hashes back to a valid value.
msg.Hashes = msg.Hashes[len(msg.Hashes)-1:]
msg.Flags = make([]byte, wire.MaxFlagsPerMerkleBlock+1)
err = msg.BtcEncode(&buf, pver)
if err == nil {
t.Errorf("encode of MsgMerkleBlock succeeded with too many " +
"flag bytes when it should have failed")
return
}
}
// take in a merkle block, parse through it, and return txids indicated
// If there's any problem return an error. Checks self-consistency only.
// doing it with a stack instead of recursion. Because...
// OK I don't know why I'm just not in to recursion OK?
func checkMBlock(m *wire.MsgMerkleBlock) ([]*wire.ShaHash, error) {
if m.Transactions == 0 {
return nil, fmt.Errorf("No transactions in merkleblock")
}
if len(m.Flags) == 0 {
return nil, fmt.Errorf("No flag bits")
}
var s []merkleNode // the stack
var r []*wire.ShaHash // slice to return; txids we care about
// set initial position to root of merkle tree
msb := nextPowerOfTwo(m.Transactions) // most significant bit possible
pos := (msb << 1) - 2 // current position in tree
var i uint8 // position in the current flag byte
var tip int
// main loop
for {
tip = len(s) - 1 // slice position of stack tip
// First check if stack operations can be performed
// is stack one filled item? that's complete.
if tip == 0 && s[0].h != nil {
if s[0].h.IsEqual(&m.Header.MerkleRoot) {
return r, nil
}
return nil, fmt.Errorf("computed root %s but expect %s\n",
s[0].h.String(), m.Header.MerkleRoot.String())
}
// is current position in the tree's dead zone? partial parent
if inDeadZone(pos, m.Transactions) {
// create merkle parent from single side (left)
s[tip-1].h = MakeMerkleParent(s[tip].h, nil)
s = s[:tip] // remove 1 from stack
pos = s[tip-1].p | 1 // move position to parent's sibling
continue
}
// does stack have 3+ items? and are last 2 items filled?
if tip > 1 && s[tip-1].h != nil && s[tip].h != nil {
//fmt.Printf("nodes %d and %d combine into %d\n",
// s[tip-1].p, s[tip].p, s[tip-2].p)
// combine two filled nodes into parent node
s[tip-2].h = MakeMerkleParent(s[tip-1].h, s[tip].h)
// remove children
s = s[:tip-1]
// move position to parent's sibling
pos = s[tip-2].p | 1
continue
}
// no stack ops to perform, so make new node from message hashes
if len(m.Hashes) == 0 {
return nil, fmt.Errorf("Ran out of hashes at position %d.", pos)
}
if len(m.Flags) == 0 {
return nil, fmt.Errorf("Ran out of flag bits.")
}
var n merkleNode // make new node
n.p = pos // set current position for new node
if pos&msb != 0 { // upper non-txid hash
if m.Flags[0]&(1<<i) == 0 { // flag bit says fill node
n.h = m.Hashes[0] // copy hash from message
m.Hashes = m.Hashes[1:] // pop off message
if pos&1 != 0 { // right side; ascend
pos = pos>>1 | msb
} else { // left side, go to sibling
pos |= 1
}
} else { // flag bit says skip; put empty on stack and descend
pos = (pos ^ msb) << 1 // descend to left
}
s = append(s, n) // push new node on stack
} else { // bottom row txid; flag bit indicates tx of interest
if pos >= m.Transactions {
// this can't happen because we check deadzone above...
return nil, fmt.Errorf("got into an invalid txid node")
}
n.h = m.Hashes[0] // copy hash from message
m.Hashes = m.Hashes[1:] // pop off message
if m.Flags[0]&(1<<i) != 0 { //txid of interest
r = append(r, n.h)
}
if pos&1 == 0 { // left side, go to sibling
pos |= 1
} // if on right side we don't move; stack ops will move next
s = append(s, n) // push new node onto the stack
}
// done with pushing onto stack; advance flag bit
i++
if i == 8 { // move to next byte
i = 0
m.Flags = m.Flags[1:]
}
}
return nil, fmt.Errorf("ran out of things to do?")
}