Add support for utreexo blocks with ublock.go

go.mod

@@ -4,8 +4,10 @@ go 1.14
 
 require (
 	github.com/aead/siphash v1.0.1
-	github.com/btcsuite/btcd v0.20.1-beta
-	github.com/davecgh/go-spew v1.1.0
+	github.com/btcsuite/btcd v0.21.0-beta.0.20201124191514-610bb55ae85c
+	github.com/davecgh/go-spew v1.1.1
 	github.com/kkdai/bstream v0.0.0-20161212061736-f391b8402d23
-	golang.org/x/crypto v0.0.0-20200115085410-6d4e4cb37c7d
+	golang.org/x/crypto v0.0.0-20200604202706-70a84ac30bf9
 )
+
+replace github.com/btcsuite/btcd => github.com/mit-dci/utcd v0.21.0-beta.0.20201218053343-e551088caf70

go.sum

@@ -1,41 +1,78 @@
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 github.com/aead/siphash v1.0.1 h1:FwHfE/T45KPKYuuSAKyyvE+oPWcaQ+CUmFW0bPlM+kg=
 github.com/aead/siphash v1.0.1/go.mod h1:Nywa3cDsYNNK3gaciGTWPwHt0wlpNV15vwmswBAUSII=
 github.com/btcsuite/btcd v0.20.1-beta h1:Ik4hyJqN8Jfyv3S4AGBOmyouMsYE3EdYODkMbQjwPGw=
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@@ -47,6 +84,7 @@ golang.org/x/sys v0.0.0-20180909124046-d0be0721c37e/go.mod h1:STP8DvDyc/dI5b8T5h
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ublock.go

@@ -0,0 +1,231 @@
+package btcutil
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+
+	"github.com/btcsuite/btcd/chaincfg/chainhash"
+	"github.com/btcsuite/btcd/wire"
+)
+
+// UBlock represents a utreexo block. It mimicks the behavior of Block in block.go
+type UBlock struct {
+	msgUBlock *wire.MsgUBlock
+
+	serializedUBlock          []byte          // Serialized bytes for the block
+	serializedUBlockNoWitness []byte          // Serialized bytes for block w/o witness data
+	blockHash                 *chainhash.Hash // Cached block hash
+	blockHeight               int32           // Height in the main block chain
+	transactions              []*Tx           // Transactions
+	txnsGenerated             bool            // ALL wrapped transactions generated
+}
+
+// MsgBlock returns the underlying wire.MsgUBlock for the Block.
+func (ub *UBlock) MsgUBlock() *wire.MsgUBlock {
+	return ub.msgUBlock
+}
+
+func (ub *UBlock) Bytes() ([]byte, error) {
+	// Return the cached serialized bytes if it has already been generated.
+	if len(ub.serializedUBlock) != 0 {
+		return ub.serializedUBlock, nil
+	}
+
+	// Serialize the MsgBlock.
+	w := bytes.NewBuffer(make([]byte, 0, ub.msgUBlock.SerializeSize()))
+	err := ub.msgUBlock.Serialize(w)
+	if err != nil {
+		return nil, err
+	}
+	serializedUBlock := w.Bytes()
+
+	// Cache the serialized bytes and return them.
+	ub.serializedUBlock = serializedUBlock
+	return serializedUBlock, nil
+}
+
+// BytesNoWitness returns the serialized bytes for the block with transactions
+// encoded without any witness data.
+func (ub *UBlock) BytesNoWitness() ([]byte, error) {
+	// Return the cached serialized bytes if it has already been generated.
+	if len(ub.serializedUBlockNoWitness) != 0 {
+		return ub.serializedUBlockNoWitness, nil
+	}
+
+	// Serialize the MsgBlock.
+	var w bytes.Buffer
+	err := ub.msgUBlock.SerializeNoWitness(&w)
+	if err != nil {
+		return nil, err
+	}
+	serializedUBlock := w.Bytes()
+
+	// Cache the serialized bytes and return them.
+	ub.serializedUBlockNoWitness = serializedUBlock
+	return serializedUBlock, nil
+}
+
+// Hash returns the block identifier hash for the Block.  This is equivalent to
+// calling BlockHash on the underlying wire.MsgBlock, however it caches the
+// result so subsequent calls are more efficient.
+func (ub *UBlock) Hash() *chainhash.Hash {
+	// Return the cached block hash if it has already been generated.
+	if ub.blockHash != nil {
+		return ub.blockHash
+	}
+
+	// Cache the block hash and return it.
+	hash := ub.msgUBlock.BlockHash()
+	ub.blockHash = &hash
+	return &hash
+}
+
+// Transactions returns a slice of wrapped transactions (btcutil.Tx) for all
+// transactions in the Block.  This is nearly equivalent to accessing the raw
+// transactions (wire.MsgTx) in the underlying wire.MsgBlock, however it
+// instead provides easy access to wrapped versions (btcutil.Tx) of them.
+func (ub *UBlock) Transactions() []*Tx {
+	// Return transactions if they have ALL already been generated.  This
+	// flag is necessary because the wrapped transactions are lazily
+	// generated in a sparse fashion.
+	if ub.txnsGenerated {
+		return ub.transactions
+	}
+
+	// Generate slice to hold all of the wrapped transactions if needed.
+	if len(ub.transactions) == 0 {
+		ub.transactions = make([]*Tx, len(ub.msgUBlock.MsgBlock.Transactions))
+	}
+
+	// Generate and cache the wrapped transactions for all that haven't
+	// already ubeen done.
+	for i, tx := range ub.transactions {
+		if tx == nil {
+			newTx := NewTx(ub.msgUBlock.MsgBlock.Transactions[i])
+			newTx.SetIndex(i)
+			ub.transactions[i] = newTx
+		}
+	}
+
+	ub.txnsGenerated = true
+
+	return ub.transactions
+}
+
+// Height returns the saved height of the block in the block chain.  This value
+// will be BlockHeightUnknown if it hasn't already explicitly been set.
+func (b *UBlock) Height() int32 {
+	return b.blockHeight
+}
+
+// SetHeight sets the height of the block in the block chain.
+func (b *UBlock) SetHeight(height int32) {
+	b.blockHeight = height
+}
+
+// NewUBlock returns a new instance of a bitcoin block given an underlying
+// wire.MsgUBlock.  See UBlock.
+func NewBUlock(msgUBlock *wire.MsgUBlock) *UBlock {
+	return &UBlock{
+		msgUBlock:   msgUBlock,
+		blockHeight: BlockHeightUnknown,
+	}
+}
+
+// NewUBlockFromReader returns a new instance of a utreexo block given a
+// Reader to deserialize the ublock.  See UBlock.
+func NewUBlockFromReader(r io.Reader) (*UBlock, error) {
+	// Deserialize the bytes into a MsgBlock.
+	var msgUBlock wire.MsgUBlock
+	err := msgUBlock.Deserialize(r)
+	if err != nil {
+		return nil, err
+	}
+
+	ub := UBlock{
+		msgUBlock:   &msgUBlock,
+		blockHeight: BlockHeightUnknown,
+	}
+	return &ub, nil
+}
+
+// NewUBlockFromBlockAndBytes returns a new instance of a utreexo block given
+// an underlying wire.MsgUBlock and the serialized bytes for it.  See UBlock.
+func NewUBlockFromBlockAndBytes(msgUBlock *wire.MsgUBlock, serializedUBlock []byte) *UBlock {
+	return &UBlock{
+		msgUBlock:        msgUBlock,
+		serializedUBlock: serializedUBlock,
+		blockHeight:      BlockHeightUnknown,
+	}
+}
+
+// Block builds a block from the UBlock. For compatibility with some functions
+// that want a block
+func (ub *UBlock) Block() *Block {
+	block := Block{
+		msgBlock:      &ub.msgUBlock.MsgBlock,
+		blockHash:     ub.blockHash,
+		blockHeight:   ub.blockHeight,
+		transactions:  ub.transactions,
+		txnsGenerated: ub.txnsGenerated,
+	}
+	return &block
+}
+
+// ProofSanity checks the consistency of a UBlock
+func (ub *UBlock) ProofSanity(inputSkipList []uint32, nl uint64, h uint8) error {
+	// get the outpoints that need proof
+	proveOPs := BlockToDelOPs(&ub.msgUBlock.MsgBlock, inputSkipList)
+
+	// ensure that all outpoints are provided in the extradata
+	if len(proveOPs) != len(ub.msgUBlock.UtreexoData.Stxos) {
+		err := fmt.Errorf("height %d %d outpoints need proofs but only %d proven\n",
+			ub.msgUBlock.UtreexoData.Height, len(proveOPs), len(ub.msgUBlock.UtreexoData.Stxos))
+		return err
+	}
+	for i, _ := range ub.msgUBlock.UtreexoData.Stxos {
+		if chainhash.Hash(proveOPs[i].Hash) != chainhash.Hash(ub.msgUBlock.UtreexoData.Stxos[i].TxHash) ||
+			proveOPs[i].Index != ub.msgUBlock.UtreexoData.Stxos[i].Index {
+			err := fmt.Errorf("block/utxoData mismatch %s v %s\n",
+				proveOPs[i].String(), ub.msgUBlock.UtreexoData.Stxos[i].OPString())
+			return err
+		}
+	}
+	// derive leafHashes from leafData
+	if !ub.msgUBlock.UtreexoData.ProofSanity(nl, h) {
+		return fmt.Errorf("height %d LeafData / Proof mismatch", ub.msgUBlock.UtreexoData.Height)
+	}
+
+	return nil
+}
+
+// BlockToDelOPs gives all the UTXOs in a block that need proofs in order to be
+// deleted.  All txinputs except for the coinbase input and utxos created
+// within the same block (on the skiplist)
+func BlockToDelOPs(
+	blk *wire.MsgBlock, skiplist []uint32) (delOPs []wire.OutPoint) {
+
+	var blockInIdx uint32
+	for txinblock, tx := range blk.Transactions {
+		if txinblock == 0 {
+			blockInIdx++ // coinbase tx always has 1 input
+			continue
+		}
+
+		// loop through inputs
+		for _, txin := range tx.TxIn {
+			// check if on skiplist.  If so, don't make leaf
+			if len(skiplist) > 0 && skiplist[0] == blockInIdx {
+				// fmt.Printf("skip %s\n", txin.PreviousOutPoint.String())
+				skiplist = skiplist[1:]
+				blockInIdx++
+				continue
+			}
+
+			delOPs = append(delOPs, txin.PreviousOutPoint)
+			blockInIdx++
+		}
+	}
+	return
+}