// NewTxDeepTxIns is used to deep copy a transaction, maintaining the old
// pointers to the TxOuts while replacing the old pointers to the TxIns with
// deep copies. This is to prevent races when the fraud proofs for the
// transactions are set by the miner.
func NewTxDeepTxIns(msgTx *wire.MsgTx) *Tx {
if msgTx == nil {
return nil
}
newMsgTx := new(wire.MsgTx)
// Copy the fixed fields.
newMsgTx.Version = msgTx.Version
newMsgTx.LockTime = msgTx.LockTime
newMsgTx.Expiry = msgTx.Expiry
// Copy the TxIns deeply.
for _, txIn := range msgTx.TxIn {
sigScrLen := len(txIn.SignatureScript)
sigScrCopy := make([]byte, sigScrLen, sigScrLen)
txInCopy := new(wire.TxIn)
txInCopy.PreviousOutPoint.Hash = txIn.PreviousOutPoint.Hash
txInCopy.PreviousOutPoint.Index = txIn.PreviousOutPoint.Index
txInCopy.PreviousOutPoint.Tree = txIn.PreviousOutPoint.Tree
txInCopy.Sequence = txIn.Sequence
txInCopy.ValueIn = txIn.ValueIn
txInCopy.BlockHeight = txIn.BlockHeight
txInCopy.BlockIndex = txIn.BlockIndex
txInCopy.SignatureScript = sigScrCopy
newMsgTx.AddTxIn(txIn)
}
// Shallow copy the TxOuts.
for _, txOut := range msgTx.TxOut {
newMsgTx.AddTxOut(txOut)
}
return &Tx{
hash: msgTx.TxHash(),
msgTx: msgTx,
txTree: wire.TxTreeUnknown,
txIndex: TxIndexUnknown,
}
}
// TestCalcSignatureHash does some rudimentary testing of msg hash calculation.
func TestCalcSignatureHash(t *testing.T) {
tx := new(wire.MsgTx)
for i := 0; i < 3; i++ {
txIn := new(wire.TxIn)
txIn.Sequence = 0xFFFFFFFF
txIn.PreviousOutPoint.Hash = chainhash.HashFuncH([]byte{byte(i)})
txIn.PreviousOutPoint.Index = uint32(i)
txIn.PreviousOutPoint.Tree = int8(0)
tx.AddTxIn(txIn)
}
for i := 0; i < 2; i++ {
txOut := new(wire.TxOut)
txOut.PkScript = []byte{0x01, 0x01, 0x02, 0x03}
txOut.Value = 0x0000FF00FF00FF00
tx.AddTxOut(txOut)
}
want, _ := hex.DecodeString("d09285b6f60c71329323bc2e76c48" +
"a462cde4e1032aa8f59c55823f1722c7f4a")
pops, _ := txscript.TstParseScript([]byte{0x01, 0x01, 0x02, 0x03})
// Test prefix caching.
msg1, err := txscript.CalcSignatureHash(pops, txscript.SigHashAll, tx, 0, nil)
if err != nil {
t.Fatalf("unexpected error %v", err.Error())
}
prefixHash := tx.TxSha()
msg2, err := txscript.CalcSignatureHash(pops, txscript.SigHashAll, tx, 0,
&prefixHash)
if err != nil {
t.Fatalf("unexpected error %v", err.Error())
}
if !bytes.Equal(msg1, want) {
t.Errorf("for sighash all sig noncached wrong msg %x given, want %x",
msg1,
want)
}
if !bytes.Equal(msg2, want) {
t.Errorf("for sighash all sig cached wrong msg %x given, want %x",
msg1,
want)
}
if !bytes.Equal(msg1, msg2) {
t.Errorf("for sighash all sig non-equivalent msgs %x and %x were "+
"returned when using a cached prefix",
msg1,
msg2)
}
// Move the index and make sure that we get a whole new hash, despite
// using the same TxOuts.
msg3, err := txscript.CalcSignatureHash(pops, txscript.SigHashAll, tx, 1,
&prefixHash)
if err != nil {
t.Fatalf("unexpected error %v", err.Error())
}
if bytes.Equal(msg1, msg3) {
t.Errorf("for sighash all sig equivalent msgs %x and %x were "+
"returned when using a cached prefix but different indices",
msg1,
msg3)
}
}
