// Receive waits for the response promised by the future and returns the raw
// block requested from the server given its hash.
func (r FutureGetBlockResult) Receive() (*dcrutil.Block, error) {
res, err := receiveFuture(r)
if err != nil {
return nil, err
}
// Unmarshal result as a string.
var blockHex string
err = json.Unmarshal(res, &blockHex)
if err != nil {
return nil, err
}
// Decode the serialized block hex to raw bytes.
serializedBlock, err := hex.DecodeString(blockHex)
if err != nil {
return nil, err
}
// Deserialize the block and return it.
var msgBlock wire.MsgBlock
err = msgBlock.Deserialize(bytes.NewReader(serializedBlock))
if err != nil {
return nil, err
}
return dcrutil.NewBlock(&msgBlock), nil
}
// NewBlockFromReader returns a new instance of a block given a
// Reader to deserialize the block. See Block.
func NewBlockFromReader(r io.Reader) (*Block, error) {
// Deserialize the bytes into a MsgBlock.
var msgBlock wire.MsgBlock
err := msgBlock.Deserialize(r)
if err != nil {
return nil, err
}
b := Block{
hash: msgBlock.BlockHash(),
msgBlock: &msgBlock,
blockHeight: int64(msgBlock.Header.Height),
}
return &b, nil
}
// TestBlockSerializeErrors performs negative tests against wire encode and
// decode of MsgBlock to confirm error paths work correctly.
func TestBlockSerializeErrors(t *testing.T) {
tests := []struct {
in *wire.MsgBlock // Value to encode
buf []byte // Serialized data
max int // Max size of fixed buffer to induce errors
writeErr error // Expected write error
readErr error // Expected read error
}{
{&testBlock, testBlockBytes, 0, io.ErrShortWrite, io.EOF}, // 0
// Force error in prev block hash.
{&testBlock, testBlockBytes, 4, io.ErrShortWrite, io.EOF}, // 1
// Force error in merkle root.
{&testBlock, testBlockBytes, 36, io.ErrShortWrite, io.EOF}, // 2
// Force error in stake root.
{&testBlock, testBlockBytes, 68, io.ErrShortWrite, io.EOF}, // 3
// Force error in vote bits.
{&testBlock, testBlockBytes, 100, io.ErrShortWrite, io.EOF}, // 4
// Force error in finalState.
{&testBlock, testBlockBytes, 102, io.ErrShortWrite, io.EOF}, // 5
// Force error in voters.
{&testBlock, testBlockBytes, 108, io.ErrShortWrite, io.EOF}, // 8
// Force error in freshstake.
{&testBlock, testBlockBytes, 110, io.ErrShortWrite, io.EOF}, // 9
// Force error in revocations.
{&testBlock, testBlockBytes, 111, io.ErrShortWrite, io.EOF}, // 10
// Force error in poolsize.
{&testBlock, testBlockBytes, 112, io.ErrShortWrite, io.EOF}, // 11
// Force error in difficulty bits.
{&testBlock, testBlockBytes, 116, io.ErrShortWrite, io.EOF}, // 12
// Force error in stake difficulty bits.
{&testBlock, testBlockBytes, 120, io.ErrShortWrite, io.EOF}, // 13
// Force error in height.
{&testBlock, testBlockBytes, 128, io.ErrShortWrite, io.EOF}, // 14
// Force error in size.
{&testBlock, testBlockBytes, 132, io.ErrShortWrite, io.EOF}, // 15
// Force error in timestamp.
{&testBlock, testBlockBytes, 136, io.ErrShortWrite, io.EOF}, // 16
// Force error in nonce.
{&testBlock, testBlockBytes, 140, io.ErrShortWrite, io.EOF}, // 17
// Force error in tx count.
{&testBlock, testBlockBytes, 180, io.ErrShortWrite, io.EOF}, // 18
// Force error in tx.
{&testBlock, testBlockBytes, 181, io.ErrShortWrite, io.EOF}, // 19
}
t.Logf("Running %d tests", len(tests))
for i, test := range tests {
// Serialize the block.
w := newFixedWriter(test.max)
err := test.in.Serialize(w)
if err != test.writeErr {
t.Errorf("Serialize #%d wrong error got: %v, want: %v",
i, err, test.writeErr)
continue
}
// Deserialize the block.
var block wire.MsgBlock
r := newFixedReader(test.max, test.buf)
err = block.Deserialize(r)
if err != test.readErr {
t.Errorf("Deserialize #%d wrong error got: %v, want: %v",
i, err, test.readErr)
continue
}
var txLocBlock wire.MsgBlock
br := bytes.NewBuffer(test.buf[0:test.max])
_, _, err = txLocBlock.DeserializeTxLoc(br)
if err != test.readErr {
t.Errorf("DeserializeTxLoc #%d wrong error got: %v, want: %v",
i, err, test.readErr)
continue
}
}
}
// TestBlockOverflowErrors performs tests to ensure deserializing blocks which
// are intentionally crafted to use large values for the number of transactions
// are handled properly. This could otherwise potentially be used as an attack
// vector.
func TestBlockOverflowErrors(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)
tests := []struct {
buf []byte // Wire encoding
pver uint32 // Protocol version for wire encoding
err error // Expected error
}{
// Block that claims to have ~uint64(0) transactions.
{
[]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
0x98, 0x20, 0x51, 0xfd, 0x1e, 0x4b, 0xa7, 0x44,
0xbb, 0xbe, 0x68, 0x0e, 0x1f, 0xee, 0x14, 0x67,
0x7b, 0xa1, 0xa3, 0xc3, 0x54, 0x0b, 0xf7, 0xb1,
0xcd, 0xb6, 0x06, 0xe8, 0x57, 0x23, 0x3e, 0x0e, // MerkleRoot
0x98, 0x20, 0x51, 0xfd, 0x1e, 0x4b, 0xa7, 0x44,
0xbb, 0xbe, 0x68, 0x0e, 0x1f, 0xee, 0x14, 0x67,
0x7b, 0xa1, 0xa3, 0xc3, 0x54, 0x0b, 0xf7, 0xb1,
0xcd, 0xb6, 0x06, 0xe8, 0x57, 0x23, 0x3e, 0x0e, // StakeRoot
0x00, 0x00, // VoteBits
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // FinalState
0x00, 0x00, // Voters
0x00, // FreshStake
0x00, // Revocations
0x00, 0x00, 0x00, 0x00, // Poolsize
0xff, 0xff, 0x00, 0x1d, // Bits
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // SBits
0x01, 0x00, 0x00, 0x00, // Height
0x01, 0x00, 0x00, 0x00, // Size
0x61, 0xbc, 0x66, 0x49, // Timestamp
0x01, 0xe3, 0x62, 0x99, // Nonce
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // ExtraData
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, // TxnCount
}, pver, &wire.MessageError{},
},
}
t.Logf("Running %d tests", len(tests))
for i, test := range tests {
// Decode from wire format.
var msg wire.MsgBlock
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
}
// Deserialize from wire format.
r = bytes.NewReader(test.buf)
err = msg.Deserialize(r)
if reflect.TypeOf(err) != reflect.TypeOf(test.err) {
t.Errorf("Deserialize #%d wrong error got: %v, want: %v",
i, err, reflect.TypeOf(test.err))
continue
}
// Deserialize with transaction location info from wire format.
br := bytes.NewBuffer(test.buf)
_, _, err = msg.DeserializeTxLoc(br)
if reflect.TypeOf(err) != reflect.TypeOf(test.err) {
t.Errorf("DeserializeTxLoc #%d wrong error got: %v, "+
"want: %v", i, err, reflect.TypeOf(test.err))
continue
}
}
}
// TestBlockSerialize tests MsgBlock serialize and deserialize.
func TestBlockSerialize(t *testing.T) {
tests := []struct {
in *wire.MsgBlock // Message to encode
out *wire.MsgBlock // Expected decoded message
buf []byte // Serialized data
txLocs []wire.TxLoc // Expected transaction locations
sTxLocs []wire.TxLoc // Expected stake transaction locations
}{
{
&testBlock,
&testBlock,
testBlockBytes,
testBlockTxLocs,
testBlockSTxLocs,
},
}
t.Logf("Running %d tests", len(tests))
for i, test := range tests {
// Serialize the block.
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.
var block wire.MsgBlock
rbuf := bytes.NewReader(test.buf)
err = block.Deserialize(rbuf)
if err != nil {
t.Errorf("Deserialize #%d error %v", i, err)
continue
}
if !reflect.DeepEqual(&block, test.out) {
t.Errorf("Deserialize #%d\n got: %s want: %s", i,
spew.Sdump(&block), spew.Sdump(test.out))
continue
}
// Deserialize the block while gathering transaction location
// information.
var txLocBlock wire.MsgBlock
br := bytes.NewBuffer(test.buf)
txLocs, sTxLocs, err := txLocBlock.DeserializeTxLoc(br)
if err != nil {
t.Errorf("DeserializeTxLoc #%d error %v", i, err)
continue
}
if !reflect.DeepEqual(&txLocBlock, test.out) {
t.Errorf("DeserializeTxLoc #%d\n got: %s want: %s", i,
spew.Sdump(&txLocBlock), spew.Sdump(test.out))
continue
}
if !reflect.DeepEqual(txLocs, test.txLocs) {
t.Errorf("DeserializeTxLoc #%d\n got: %s want: %s", i,
spew.Sdump(txLocs), spew.Sdump(test.txLocs))
continue
}
if !reflect.DeepEqual(sTxLocs, test.sTxLocs) {
t.Errorf("DeserializeTxLoc, sTxLocs #%d\n got: %s want: %s", i,
spew.Sdump(sTxLocs), spew.Sdump(test.sTxLocs))
continue
}
}
}
