// 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(1)
// 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.MaxTxPerTxTree+1)
numHashesOffset := 140
exceedMaxHashes := make([]byte, numHashesOffset)
copy(exceedMaxHashes, testMerkleBlockBytes[: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 := 210
exceedMaxFlagBytes := make([]byte, numFlagBytesOffset)
copy(exceedMaxFlagBytes, testMerkleBlockBytes[: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, io.ErrUnexpectedEOF},
// Block that claims to have more than max allowed flag bytes.
{exceedMaxFlagBytes, pver, io.ErrUnexpectedEOF},
}
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 hashes based on the passed block and filter.
func NewMerkleBlock(block *dcrutil.Block, filter *Filter) (*wire.MsgMerkleBlock, []*chainhash.Hash) {
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 matchedHashes []*chainhash.Hash
for _, tx := range block.Transactions() {
if filter.MatchTxAndUpdate(tx) {
mBlock.matchedBits = append(mBlock.matchedBits, 0x01)
matchedHashes = append(matchedHashes, tx.Sha())
} else {
mBlock.matchedBits = append(mBlock.matchedBits, 0x00)
}
mBlock.allHashes = append(mBlock.allHashes, tx.Sha())
}
// 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: uint32(mBlock.numTx),
Hashes: make([]*chainhash.Hash, 0, len(mBlock.finalHashes)),
Flags: make([]byte, (len(mBlock.bits)+7)/8),
}
for _, sha := range mBlock.finalHashes {
msgMerkleBlock.AddTxHash(sha)
}
for i := uint32(0); i < uint32(len(mBlock.bits)); i++ {
msgMerkleBlock.Flags[i/8] |= mBlock.bits[i] << (i % 8)
}
return &msgMerkleBlock, matchedHashes
}
// 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.
{
&testMerkleBlock, &testMerkleBlock,
testMerkleBlockBytes, wire.ProtocolVersion,
},
}
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
}
}
}
// TestMerkleBlock tests the MsgMerkleBlock API.
func TestMerkleBlock(t *testing.T) {
pver := wire.ProtocolVersion
// Test block header.
bh := wire.NewBlockHeader(
int32(pver),
&testBlock.Header.PrevBlock, // PrevHash
&testBlock.Header.MerkleRoot, // MerkleRootHash
&testBlock.Header.StakeRoot, // StakeRoot
uint16(0x0000), // VoteBits
[6]byte{0x00, 0x00, 0x00, 0x00, 0x00, 0x00}, // FinalState
uint16(0x0000), // Voters
uint8(0x00), // FreshStake
uint8(0x00), // Revocations
uint32(0), // Poolsize
testBlock.Header.Bits, // Bits
int64(0x0000000000000000), // Sbits
uint32(1), // Height
uint32(0), // Size
testBlock.Header.Nonce, // Nonce
[36]byte{}, // ExtraData
)
// 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.MaxTxPerTxTree; i++ {
rand.Read(data)
hash, err := chainhash.NewHash(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
}
if err = msg.AddSTxHash(hash); err != nil {
t.Errorf("AddSTxHash failed: %v\n", err)
return
}
}
// Add one more Tx to test failure.
rand.Read(data)
hash, err := chainhash.NewHash(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
}
// Add one more STx to test failure.
rand.Read(data)
hash, err = chainhash.NewHash(data)
if err != nil {
t.Errorf("NewShaHash failed: %v\n", err)
return
}
if err = msg.AddSTxHash(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
}
}
// 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(1)
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. [0]
{
&testMerkleBlock, testMerkleBlockBytes, pver, 0,
io.ErrShortWrite, io.EOF,
},
// Force error in prev block hash. [1]
{
&testMerkleBlock, testMerkleBlockBytes, pver, 4,
io.ErrShortWrite, io.EOF,
},
// Force error in merkle root. [2]
{
&testMerkleBlock, testMerkleBlockBytes, pver, 36,
io.ErrShortWrite, io.EOF,
},
// Force error in stake merkle root. [3]
{
&testMerkleBlock, testMerkleBlockBytes, pver, 68,
io.ErrShortWrite, io.EOF,
},
// Force error in VoteBits. [4]
{
&testMerkleBlock, testMerkleBlockBytes, pver, 100,
io.ErrShortWrite, io.EOF,
},
// Force error in FinalState. [5]
{
&testMerkleBlock, testMerkleBlockBytes, pver, 102,
io.ErrShortWrite, io.EOF,
},
// Force error in Voters. [6]
{
&testMerkleBlock, testMerkleBlockBytes, pver, 108,
io.ErrShortWrite, io.EOF,
},
// Force error in FreshStake. [7]
{
&testMerkleBlock, testMerkleBlockBytes, pver, 110,
io.ErrShortWrite, io.EOF,
},
// Force error in Revocations. [8]
{
&testMerkleBlock, testMerkleBlockBytes, pver, 111,
io.ErrShortWrite, io.EOF,
},
// Force error in poolsize. [9]
{
&testMerkleBlock, testMerkleBlockBytes, pver, 112,
io.ErrShortWrite, io.EOF,
},
// Force error in difficulty bits. [10]
{
&testMerkleBlock, testMerkleBlockBytes, pver, 116,
io.ErrShortWrite, io.EOF,
},
// Force error in stake difficulty bits. [11]
{
&testMerkleBlock, testMerkleBlockBytes, pver, 120,
io.ErrShortWrite, io.EOF,
},
// Force error in height. [12]
{
&testMerkleBlock, testMerkleBlockBytes, pver, 128,
io.ErrShortWrite, io.EOF,
},
// Force error in size. [13]
{
&testMerkleBlock, testMerkleBlockBytes, pver, 132,
io.ErrShortWrite, io.EOF,
},
// Force error in timestamp. [14]
{
&testMerkleBlock, testMerkleBlockBytes, pver, 136,
io.ErrShortWrite, io.EOF,
},
// Force error in header nonce. [15]
{
&testMerkleBlock, testMerkleBlockBytes, pver, 140,
io.ErrShortWrite, io.EOF,
},
// Force error in transaction count. [16]
{
&testMerkleBlock, testMerkleBlockBytes, pver, 180,
io.ErrShortWrite, io.EOF,
},
// Force error in num hashes. [17]
{
&testMerkleBlock, testMerkleBlockBytes, pver, 184,
io.ErrShortWrite, io.EOF,
},
// Force error in hashes. [18]
{
&testMerkleBlock, testMerkleBlockBytes, pver, 185,
io.ErrShortWrite, io.EOF,
},
// Force error in num flag bytes. [19]
{
&testMerkleBlock, testMerkleBlockBytes, pver, 254,
io.ErrShortWrite, io.EOF,
},
// Force error in flag bytes. [20]
{
&testMerkleBlock, testMerkleBlockBytes, pver, 255,
io.ErrShortWrite, io.EOF,
},
}
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
}
}
}
}
