Merge pull request #17 from libsv/feat/PreviousTxIDBytes

input.go

@@ -25,6 +25,7 @@ sequence_no	               normally 0xFFFFFFFF; irrelevant unless transaction's
 // DO NOT CHANGE ORDER - Optimized for memory via maligned
 //
 type Input struct {
+	PreviousTxIDBytes  []byte
 	PreviousTxID       string
 	PreviousTxSatoshis uint64
 	PreviousTxScript   *bscript.Script
@@ -61,6 +62,7 @@ func NewInputFromBytes(bytes []byte) (*Input, int, error) {
 	}
 
 	return &Input{
+		PreviousTxIDBytes:  ReverseBytes(bytes[0:32]),
 		PreviousTxID:       hex.EncodeToString(ReverseBytes(bytes[0:32])),
 		PreviousTxOutIndex: binary.LittleEndian.Uint32(bytes[32:36]),
 		SequenceNumber:     binary.LittleEndian.Uint32(bytes[offset+int(l):]),
@@ -71,12 +73,19 @@ func NewInputFromBytes(bytes []byte) (*Input, int, error) {
 // NewInputFromUTXO returns a transaction input from the UTXO fields provided.
 func NewInputFromUTXO(prevTxID string, prevTxIndex uint32, prevTxSats uint64,
 	prevTxScript string, nSeq uint32) (*Input, error) {
+
 	pts, err := bscript.NewFromHexString(prevTxScript)
 	if err != nil {
 		return nil, err
 	}
 
+	ptxid, err := hex.DecodeString(prevTxID)
+	if err != nil {
+		return nil, err
+	}
+
 	return &Input{
+		PreviousTxIDBytes:  ptxid,
 		PreviousTxID:       prevTxID,
 		PreviousTxOutIndex: prevTxIndex,
 		PreviousTxSatoshis: prevTxSats,
@@ -105,10 +114,7 @@ sequence:     %x
 func (i *Input) ToBytes(clear bool) []byte {
 	h := make([]byte, 0)
 
-	// todo: not checking error
-	pid, _ := hex.DecodeString(i.PreviousTxID)
-
-	h = append(h, ReverseBytes(pid)...)
+	h = append(h, ReverseBytes(i.PreviousTxIDBytes)...)
 	h = append(h, GetLittleEndianBytes(i.PreviousTxOutIndex, 4)...)
 	if clear {
 		h = append(h, 0x00)

signaturehash.go

@@ -2,7 +2,6 @@ package bt
 
 import (
 	"encoding/binary"
-	"encoding/hex"
 	"errors"
 
 	"github.com/libsv/go-bt/crypto"
@@ -30,7 +29,7 @@ func (tx *Tx) GetInputPreimage(inputNumber uint32, sigHashFlag sighash.Flag) ([]
 
 	in := tx.Inputs[inputNumber]
 
-	if in.PreviousTxID == "" {
+	if len(in.PreviousTxIDBytes) == 0 {
 		return nil, errors.New("'PreviousTxID' not supplied")
 	}
 	if in.PreviousTxScript == nil {
@@ -73,8 +72,7 @@ func (tx *Tx) GetInputPreimage(inputNumber uint32, sigHashFlag sighash.Flag) ([]
 	buf = append(buf, hashSequence...)
 
 	//  outpoint (32-byte hash + 4-byte little endian)
-	txid, _ := hex.DecodeString(in.PreviousTxID[:])
-	buf = append(buf, ReverseBytes(txid)...)
+	buf = append(buf, ReverseBytes(in.PreviousTxIDBytes)...)
 	oi := make([]byte, 4)
 	binary.LittleEndian.PutUint32(oi, in.PreviousTxOutIndex)
 	buf = append(buf, oi...)
@@ -114,9 +112,7 @@ func (tx *Tx) getPreviousOutHash() []byte {
 	buf := make([]byte, 0)
 
 	for _, in := range tx.Inputs {
-		// todo: error ignored?
-		txid, _ := hex.DecodeString(in.PreviousTxID[:])
-		buf = append(buf, ReverseBytes(txid)...)
+		buf = append(buf, ReverseBytes(in.PreviousTxIDBytes)...)
 		oi := make([]byte, 4)
 		binary.LittleEndian.PutUint32(oi, in.PreviousTxOutIndex)
 		buf = append(buf, oi...)

tx.go

@@ -146,6 +146,7 @@ func (tx *Tx) AddInputFromTx(pvsTx *Tx, matchPK []byte) error {
 			continue
 		}
 		tx.AddInput(&Input{
+			PreviousTxIDBytes:  pvsTx.GetTxIDAsBytes(),
 			PreviousTxID:       pvsTx.GetTxID(),
 			PreviousTxOutIndex: uint32(i),
 			PreviousTxSatoshis: utxo.Satoshis,
@@ -163,7 +164,13 @@ func (tx *Tx) From(txID string, vout uint32, prevTxLockingScript string, satoshi
 		return err
 	}
 
+	ptid, err := hex.DecodeString(txID)
+	if err != nil {
+		return err
+	}
+
 	tx.AddInput(&Input{
+		PreviousTxIDBytes:  ptid,
 		PreviousTxID:       txID,
 		PreviousTxOutIndex: vout,
 		PreviousTxSatoshis: satoshis,

tx_test.go

@@ -60,7 +60,9 @@ func TestNewTxFromString(t *testing.T) {
 		assert.Equal(t, 1, len(tx.Inputs))
 
 		// Create a new unlocking script
+		ptid, _ := hex.DecodeString("9c5b1428aaad5e9b0196c89be8628b366f33c7b22933da0489b921d487a7cb1c")
 		i := bt.Input{
+			PreviousTxIDBytes:  ptid,
 			PreviousTxID:       "9c5b1428aaad5e9b0196c89be8628b366f33c7b22933da0489b921d487a7cb1c",
 			PreviousTxOutIndex: 0,
 			SequenceNumber:     bt.DefaultSequenceNumber,