示例#1
0
func (bltnB *BulletinBuilder) Build() (*btcwire.MsgTx, error) {
	utxo, err := selectUnspent(bltnB.SatNeeded(), bltnB.Params)
	if err != nil {
		return nil, err
	}
	msgtx := btcwire.NewMsgTx()
	// Add data storing txouts.
	txouts, err := bltnB.Bulletin.TxOuts(bltnB.BurnAmnt, bltnB.Params.NetParams)
	if err != nil {
		return nil, err
	}
	msgtx.TxOut = txouts

	txin := btcwire.NewTxIn(utxo.OutPoint, []byte{})
	msgtx.AddTxIn(txin)

	// Deal with change
	changeAmnt := utxo.TxOut.Value - bltnB.SatNeeded()
	if changeAmnt > bltnB.Params.DustAmnt {
		changeOut, err := makeChange(changeAmnt, bltnB.Params)
		if err != nil {
			return nil, err
		}
		msgtx.AddTxOut(changeOut)
	}

	// Sign the Bulletin
	privkey := utxo.Wif.PrivKey
	scriptSig, err := btcscript.SignatureScript(msgtx, 0, utxo.TxOut.PkScript, btcscript.SigHashAll, privkey, true)
	if err != nil {
		return nil, err
	}
	txin.SignatureScript = scriptSig
	return msgtx, nil
}
示例#2
0
func (fanB *FanOutBuilder) Build() (*btcwire.MsgTx, error) {
	totalSpent := fanB.SatNeeded()

	// Compose a set of Txins with enough to fund this transactions needs
	inParamSet, totalIn, err := composeUnspents(
		totalSpent,
		fanB.Params)
	if err != nil {
		return nil, err
	}

	msgtx := btcwire.NewMsgTx()
	// funding inputs speced out with blank
	for _, inpParam := range inParamSet {
		txin := btcwire.NewTxIn(inpParam.OutPoint, []byte{})
		msgtx.AddTxIn(txin)
	}

	for i := range fanB.Builders {
		builder := fanB.Builders[i]
		amnt := builder.SatNeeded()
		for j := int64(0); j < fanB.Copies; j++ {
			addr, err := newAddr(fanB.Params.Client)
			if err != nil {
				return nil, err
			}
			script, _ := btcscript.PayToAddrScript(addr)
			txout := btcwire.NewTxOut(amnt, script)
			msgtx.AddTxOut(txout)
		}
	}

	changeAddr, err := newAddr(fanB.Params.Client)
	if err != nil {
		return nil, err
	}
	// change to solve unevenness
	change, ok := changeOutput(totalIn-totalSpent, fanB.Params.DustAmnt, changeAddr)
	if ok {
		msgtx.AddTxOut(change)
	}

	// sign msgtx for each input
	for i, inpParam := range inParamSet {
		privkey := inpParam.Wif.PrivKey
		subscript := inpParam.TxOut.PkScript
		sigflag := btcscript.SigHashAll
		scriptSig, err := btcscript.SignatureScript(msgtx, i, subscript,
			sigflag, privkey, true)
		if err != nil {
			return nil, err
		}
		msgtx.TxIn[i].SignatureScript = scriptSig
	}
	fanB.Log(fmt.Sprintf("InVal: %d\n", sumInputs(inParamSet)))
	fanB.Log(fmt.Sprintf("OutVal: %d\n", sumOutputs(msgtx)))

	return msgtx, nil
}
示例#3
0
func signScript(tx *btcwire.MsgTx, idx int, subscript []byte, privKey string) ([]byte, error) {
	wif, err := btcutil.DecodeWIF(privKey)
	if err != nil {
		return nil, err
	}

	return btcscript.SignatureScript(tx, idx, subscript, SIGHASH_ALL, wif.PrivKey.ToECDSA(), wif.CompressPubKey)
}
func (shsB *SigHashSingleBuilder) Build() (*btcwire.MsgTx, error) {
	// RPC to setup previous TX
	utxo, err := selectUnspent(shsB.SatNeeded()+shsB.Params.DustAmnt, shsB.Params)
	if err != nil {
		return nil, err
	}

	oldTxOut := utxo.TxOut
	outpoint := utxo.OutPoint
	wifkey := utxo.Wif

	// Transaction building

	txin := btcwire.NewTxIn(outpoint, []byte{})

	// notice amount in
	total := oldTxOut.Value
	changeval := total - (shsB.SatNeeded())
	change, ok := changeOutput(changeval, shsB.Params.DustAmnt,
		wifToAddr(wifkey, shsB.Params.NetParams))
	if !ok {
		return nil, errors.New("Not enough for change.")
	}
	// Blank permutable txout for users to play with
	blankval := shsB.Params.InTarget - shsB.Params.Fee
	blank := btcwire.NewTxOut(blankval, change.PkScript) //[]byte{})

	msgtx := btcwire.NewMsgTx()
	msgtx.AddTxIn(txin)
	msgtx.AddTxOut(change)
	msgtx.AddTxOut(blank)

	subscript := oldTxOut.PkScript
	privkey := wifkey.PrivKey
	scriptSig, err := btcscript.SignatureScript(msgtx, 0, subscript, btcscript.SigHashSingle, privkey, true)
	if err != nil {
		return nil, err
	}

	msgtx.TxIn[0].SignatureScript = scriptSig
	// This demonstrates that we can sign and then permute a txout
	//msgtx.TxOut[1].PkScript = oldTxOut.PkScript
	blank.Value = blankval + 1

	return msgtx, nil
}
示例#5
0
func (builder *ToAddrBuilder) Build() (*btcwire.MsgTx, error) {

	utxo, err := selectUnspent(builder.SatNeeded(), builder.Params)
	if err != nil {
		return nil, err
	}

	txin := btcwire.NewTxIn(utxo.OutPoint, []byte{})

	msgtx := btcwire.NewMsgTx()
	msgtx.AddTxIn(txin)
	// add send to addr
	valout := builder.Params.InTarget - builder.Params.Fee
	outscript, _ := btcscript.PayToAddrScript(builder.Addr)
	txout := btcwire.NewTxOut(valout, outscript)

	msgtx.AddTxOut(txout)

	// add send to change addr
	total := utxo.TxOut.Value
	changeval := total - builder.SatNeeded()
	if changeval > builder.Params.DustAmnt {
		// Change needed
		changeAddr, err := builder.Params.Client.GetNewAddress()
		if err != nil {
			return nil, err
		}
		change, ok := changeOutput(changeval, builder.Params.DustAmnt, changeAddr)
		if ok {
			msgtx.AddTxOut(change)
		}
	}

	subscript := utxo.TxOut.PkScript
	privkey := utxo.Wif.PrivKey
	scriptSig, err := btcscript.SignatureScript(msgtx, 0, subscript, btcscript.SigHashAll, privkey, true)
	if err != nil {
		return nil, err
	}
	txin.SignatureScript = scriptSig

	return msgtx, nil
}
示例#6
0
func (ndB *NullDataBuilder) Build() (*btcwire.MsgTx, error) {

	utxo, err := specificUnspent(ndB.SatNeeded(), ndB.Params)
	if err != nil {
		return nil, err
	}

	msgtx := btcwire.NewMsgTx()

	if len(ndB.Data) > 40 {
		return nil, errors.New("Data is too long to make this a standard tx.")
	}

	// OP Return output
	retbuilder := btcscript.NewScriptBuilder().AddOp(btcscript.OP_RETURN).AddData(ndB.Data)
	op_return := btcwire.NewTxOut(0, retbuilder.Script())
	msgtx.AddTxOut(op_return)

	if ndB.Change {
		// change ouput
		addr, _ := newAddr(ndB.Params.Client)
		change, ok := changeOutput(ndB.SatNeeded()-ndB.Params.Fee, ndB.Params.DustAmnt, addr)
		if !ok {
			return nil, errors.New("Not enough for change")
		}
		msgtx.AddTxOut(change)
	}

	// funding input
	txin := btcwire.NewTxIn(utxo.OutPoint, []byte{})
	msgtx.AddTxIn(txin)

	// sign msgtx
	privkey := utxo.Wif.PrivKey
	scriptSig, err := btcscript.SignatureScript(msgtx, 0, utxo.TxOut.PkScript, btcscript.SigHashAll, privkey, true)
	if err != nil {
		return nil, err
	}
	txin.SignatureScript = scriptSig

	return msgtx, nil
}
示例#7
0
// A transaction that contains only dust ouputs and obeys the TxBuilder interface
func (builder *DustBuilder) Build() (*btcwire.MsgTx, error) {

	var inparams *TxInParams
	var err error
	inparams, err = specificUnspent(
		builder.SatNeeded(),
		builder.Params)
	if err != nil {
		return nil, err
	}

	oldTxOut := inparams.TxOut
	outpoint := inparams.OutPoint
	wifkey := inparams.Wif

	msgtx := btcwire.NewMsgTx()

	txin := btcwire.NewTxIn(outpoint, []byte{})
	msgtx.AddTxIn(txin)

	for i := int64(0); i < builder.NumOuts; i++ {
		dumb := bytes.Repeat([]byte{66}, 20)
		addr := dataAddr(dumb, builder.Params.NetParams)
		addrScript, err := btcscript.PayToAddrScript(addr)
		if err != nil {
			return nil, err
		}
		txOut := btcwire.NewTxOut(builder.Params.DustAmnt, addrScript)
		msgtx.AddTxOut(txOut)
	}

	// sign as usual
	privkey := wifkey.PrivKey
	sig, err := btcscript.SignatureScript(msgtx, 0, oldTxOut.PkScript, btcscript.SigHashAll, privkey, true)
	if err != nil {
		return nil, err
	}
	txin.SignatureScript = sig

	return msgtx, nil
}
示例#8
0
func (pkhB *PubKeyHashBuilder) Build() (*btcwire.MsgTx, error) {

	inparams, err := specificUnspent(pkhB.SatNeeded(), pkhB.Params)
	if err != nil {
		return nil, err
	}

	msgtx := btcwire.NewMsgTx()

	txin := btcwire.NewTxIn(inparams.OutPoint, []byte{})
	msgtx.AddTxIn(txin)

	for i := int64(0); i < pkhB.NumOuts; i++ {
		addr, err := newAddr(pkhB.Params.Client)
		if err != nil {
			return nil, err
		}
		addrScript, err := btcscript.PayToAddrScript(addr)
		amntSend := pkhB.eachOutVal()
		if amntSend < pkhB.Params.DustAmnt {
			return nil, errors.New("Output would be under the dust limit")
		}
		txout := btcwire.NewTxOut(pkhB.eachOutVal(), addrScript)
		msgtx.AddTxOut(txout)
	}
	privkey := inparams.Wif.PrivKey
	sig, err := btcscript.SignatureScript(msgtx,
		0,
		inparams.TxOut.PkScript,
		btcscript.SigHashAll,
		privkey,
		true)
	if err != nil {
		return nil, err
	}
	txin.SignatureScript = sig

	return msgtx, nil
}
示例#9
0
// TODO This will add multisig Txouts to the unspent set be AWARE
func (msB *MultiSigBuilder) Build() (*btcwire.MsgTx, error) {

	utxo, err := specificUnspent(msB.SatNeeded(), msB.Params)
	if err != nil {
		return nil, err
	}
	msgtx := btcwire.NewMsgTx()

	txin := btcwire.NewTxIn(utxo.OutPoint, []byte{})
	msgtx.AddTxIn(txin)

	for _, pubkeys := range msB.PubKeyList {
		// M pubkey pubkey pubkey N OP_CHECKMULTISIG
		scriptBuilder := btcscript.NewScriptBuilder().AddInt64(msB.M)
		for _, pk := range pubkeys {
			scriptBuilder = scriptBuilder.AddData(pk)
		}
		scriptBuilder = scriptBuilder.AddInt64(msB.N).AddOp(btcscript.OP_CHECKMULTISIG)
		PkScript := scriptBuilder.Script()
		txout := btcwire.NewTxOut(msB.eachOutVal(), PkScript)
		msgtx.AddTxOut(txout)
	}

	// Sign this puppy
	privkey := utxo.Wif.PrivKey
	subscript := utxo.TxOut.PkScript
	sigflag := btcscript.SigHashAll
	scriptSig, err := btcscript.SignatureScript(msgtx, 0, subscript,
		sigflag, privkey, true)
	if err != nil {
		return nil, err
	}

	msgtx.TxIn[0].SignatureScript = scriptSig

	return msgtx, nil
}
示例#10
0
// txToPairs creates a raw transaction sending the amounts for each
// address/amount pair and fee to each address and the miner.  minconf
// specifies the minimum number of confirmations required before an
// unspent output is eligible for spending. Leftover input funds not sent
// to addr or as a fee for the miner are sent to a newly generated
// address. If change is needed to return funds back to an owned
// address, changeUtxo will point to a unconfirmed (height = -1, zeroed
// block hash) Utxo.  ErrInsufficientFunds is returned if there are not
// enough eligible unspent outputs to create the transaction.
func (a *Account) txToPairs(pairs map[string]btcutil.Amount,
	minconf int) (*CreatedTx, error) {

	// Wallet must be unlocked to compose transaction.
	if a.IsLocked() {
		return nil, wallet.ErrWalletLocked
	}

	// Create a new transaction which will include all input scripts.
	msgtx := btcwire.NewMsgTx()

	// Calculate minimum amount needed for inputs.
	var amt btcutil.Amount
	for _, v := range pairs {
		// Error out if any amount is negative.
		if v <= 0 {
			return nil, ErrNonPositiveAmount
		}
		amt += v
	}

	// Add outputs to new tx.
	for addrStr, amt := range pairs {
		addr, err := btcutil.DecodeAddress(addrStr, cfg.Net())
		if err != nil {
			return nil, fmt.Errorf("cannot decode address: %s", err)
		}

		// Add output to spend amt to addr.
		pkScript, err := btcscript.PayToAddrScript(addr)
		if err != nil {
			return nil, fmt.Errorf("cannot create txout script: %s", err)
		}
		txout := btcwire.NewTxOut(int64(amt), pkScript)
		msgtx.AddTxOut(txout)
	}

	// Get current block's height and hash.
	bs, err := GetCurBlock()
	if err != nil {
		return nil, err
	}

	// Make a copy of msgtx before any inputs are added.  This will be
	// used as a starting point when trying a fee and starting over with
	// a higher fee if not enough was originally chosen.
	txNoInputs := msgtx.Copy()

	unspent, err := a.TxStore.UnspentOutputs()
	if err != nil {
		return nil, err
	}

	var selectedInputs []*txstore.Credit
	// These are nil/zeroed until a change address is needed, and reused
	// again in case a change utxo has already been chosen.
	var changeAddr btcutil.Address

	// Get the number of satoshis to increment fee by when searching for
	// the minimum tx fee needed.
	fee := btcutil.Amount(0)
	for {
		msgtx = txNoInputs.Copy()

		// Select unspent outputs to be used in transaction based on the amount
		// neededing to sent, and the current fee estimation.
		inputs, btcin, err := selectInputs(unspent, amt+fee, minconf)
		if err != nil {
			return nil, err
		}

		// Check if there are leftover unspent outputs, and return coins back to
		// a new address we own.
		//
		// TODO: change needs to be inserted into a random txout index, or else
		// this is a privacy risk.
		change := btcin - amt - fee
		if change > 0 {
			// Get a new change address if one has not already been found.
			if changeAddr == nil {
				changeAddr, err = a.ChangeAddress(&bs, cfg.KeypoolSize)
				if err != nil {
					return nil, fmt.Errorf("failed to get next address: %s", err)
				}

				// Mark change address as belonging to this account.
				AcctMgr.MarkAddressForAccount(changeAddr, a)
			}

			// Spend change.
			pkScript, err := btcscript.PayToAddrScript(changeAddr)
			if err != nil {
				return nil, fmt.Errorf("cannot create txout script: %s", err)
			}
			msgtx.AddTxOut(btcwire.NewTxOut(int64(change), pkScript))
		}

		// Selected unspent outputs become new transaction's inputs.
		for _, ip := range inputs {
			msgtx.AddTxIn(btcwire.NewTxIn(ip.OutPoint(), nil))
		}
		for i, input := range inputs {
			_, addrs, _, _ := input.Addresses(cfg.Net())
			if len(addrs) != 1 {
				continue
			}
			apkh, ok := addrs[0].(*btcutil.AddressPubKeyHash)
			if !ok {
				continue // don't handle inputs to this yes
			}

			ai, err := a.Address(apkh)
			if err != nil {
				return nil, fmt.Errorf("cannot get address info: %v", err)
			}

			pka := ai.(wallet.PubKeyAddress)

			privkey, err := pka.PrivKey()
			if err == wallet.ErrWalletLocked {
				return nil, wallet.ErrWalletLocked
			} else if err != nil {
				return nil, fmt.Errorf("cannot get address key: %v", err)
			}

			sigscript, err := btcscript.SignatureScript(msgtx, i,
				input.TxOut().PkScript, btcscript.SigHashAll, privkey,
				ai.Compressed())
			if err != nil {
				return nil, fmt.Errorf("cannot create sigscript: %s", err)
			}
			msgtx.TxIn[i].SignatureScript = sigscript
		}

		noFeeAllowed := false
		if !cfg.DisallowFree {
			noFeeAllowed = allowFree(bs.Height, inputs, msgtx.SerializeSize())
		}
		if minFee := minimumFee(msgtx, noFeeAllowed); fee < minFee {
			fee = minFee
		} else {
			selectedInputs = inputs
			break
		}
	}

	// Validate msgtx before returning the raw transaction.
	flags := btcscript.ScriptCanonicalSignatures
	bip16 := time.Now().After(btcscript.Bip16Activation)
	if bip16 {
		flags |= btcscript.ScriptBip16
	}
	for i, txin := range msgtx.TxIn {
		engine, err := btcscript.NewScript(txin.SignatureScript,
			selectedInputs[i].TxOut().PkScript, i, msgtx, flags)
		if err != nil {
			return nil, fmt.Errorf("cannot create script engine: %s", err)
		}
		if err = engine.Execute(); err != nil {
			return nil, fmt.Errorf("cannot validate transaction: %s", err)
		}
	}

	buf := bytes.NewBuffer(nil)
	buf.Grow(msgtx.SerializeSize())
	msgtx.BtcEncode(buf, btcwire.ProtocolVersion)
	info := &CreatedTx{
		tx:         btcutil.NewTx(msgtx),
		inputs:     selectedInputs,
		changeAddr: changeAddr,
	}
	return info, nil
}
示例#11
0
// txToPairs creates a raw transaction sending the amounts for each
// address/amount pair and fee to each address and the miner.  minconf
// specifies the minimum number of confirmations required before an
// unspent output is eligible for spending. Leftover input funds not sent
// to addr or as a fee for the miner are sent to a newly generated
// address. If change is needed to return funds back to an owned
// address, changeUtxo will point to a unconfirmed (height = -1, zeroed
// block hash) Utxo.  ErrInsufficientFunds is returned if there are not
// enough eligible unspent outputs to create the transaction.
func (a *Account) txToPairs(pairs map[string]btcutil.Amount,
	minconf int) (*CreatedTx, error) {

	// Wallet must be unlocked to compose transaction.
	if a.IsLocked() {
		return nil, wallet.ErrWalletLocked
	}

	// Create a new transaction which will include all input scripts.
	msgtx := btcwire.NewMsgTx()

	// Calculate minimum amount needed for inputs.
	var amt btcutil.Amount
	for _, v := range pairs {
		// Error out if any amount is negative.
		if v <= 0 {
			return nil, ErrNonPositiveAmount
		}
		amt += v
	}

	// Add outputs to new tx.
	for addrStr, amt := range pairs {
		addr, err := btcutil.DecodeAddress(addrStr, activeNet.Params)
		if err != nil {
			return nil, fmt.Errorf("cannot decode address: %s", err)
		}

		// Add output to spend amt to addr.
		pkScript, err := btcscript.PayToAddrScript(addr)
		if err != nil {
			return nil, fmt.Errorf("cannot create txout script: %s", err)
		}
		txout := btcwire.NewTxOut(int64(amt), pkScript)
		msgtx.AddTxOut(txout)
	}

	// Get current block's height and hash.
	bs, err := GetCurBlock()
	if err != nil {
		return nil, err
	}

	// Make a copy of msgtx before any inputs are added.  This will be
	// used as a starting point when trying a fee and starting over with
	// a higher fee if not enough was originally chosen.
	txNoInputs := msgtx.Copy()

	unspent, err := a.TxStore.UnspentOutputs()
	if err != nil {
		return nil, err
	}

	// Filter out unspendable outputs, that is, remove those that (at this
	// time) are not P2PKH outputs.  Other inputs must be manually included
	// in transactions and sent (for example, using createrawtransaction,
	// signrawtransaction, and sendrawtransaction).
	eligible := make([]txstore.Credit, 0, len(unspent))
	for i := range unspent {
		switch btcscript.GetScriptClass(unspent[i].TxOut().PkScript) {
		case btcscript.PubKeyHashTy:
			if !unspent[i].Confirmed(minconf, bs.Height) {
				continue
			}
			// Coinbase transactions must have have reached maturity
			// before their outputs may be spent.
			if unspent[i].IsCoinbase() {
				target := btcchain.CoinbaseMaturity
				if !unspent[i].Confirmed(target, bs.Height) {
					continue
				}
			}

			// Locked unspent outputs are skipped.
			if a.LockedOutpoint(*unspent[i].OutPoint()) {
				continue
			}

			eligible = append(eligible, unspent[i])
		}
	}

	// Sort eligible inputs, as selectInputs expects these to be sorted
	// by amount in reverse order.
	sort.Sort(sort.Reverse(ByAmount(eligible)))

	var selectedInputs []txstore.Credit
	// changeAddr is nil/zeroed until a change address is needed, and reused
	// again in case a change utxo has already been chosen.
	var changeAddr btcutil.Address

	// Get the number of satoshis to increment fee by when searching for
	// the minimum tx fee needed.
	fee := btcutil.Amount(0)
	for {
		msgtx = txNoInputs.Copy()

		// Select eligible outputs to be used in transaction based on the amount
		// neededing to sent, and the current fee estimation.
		inputs, btcin, err := selectInputs(eligible, amt, fee, minconf)
		if err != nil {
			return nil, err
		}

		// Check if there are leftover unspent outputs, and return coins back to
		// a new address we own.
		change := btcin - amt - fee
		if change > 0 {
			// Get a new change address if one has not already been found.
			if changeAddr == nil {
				changeAddr, err = a.ChangeAddress(&bs, cfg.KeypoolSize)
				if err != nil {
					return nil, fmt.Errorf("failed to get next address: %s", err)
				}

				// Mark change address as belonging to this account.
				AcctMgr.MarkAddressForAccount(changeAddr, a)
			}

			// Spend change.
			pkScript, err := btcscript.PayToAddrScript(changeAddr)
			if err != nil {
				return nil, fmt.Errorf("cannot create txout script: %s", err)
			}
			msgtx.AddTxOut(btcwire.NewTxOut(int64(change), pkScript))

			// Randomize index of the change output.
			rng := badrand.New(badrand.NewSource(time.Now().UnixNano()))
			r := rng.Int31n(int32(len(msgtx.TxOut))) // random index
			c := len(msgtx.TxOut) - 1                // change index
			msgtx.TxOut[r], msgtx.TxOut[c] = msgtx.TxOut[c], msgtx.TxOut[r]
		}

		// Selected unspent outputs become new transaction's inputs.
		for _, ip := range inputs {
			msgtx.AddTxIn(btcwire.NewTxIn(ip.OutPoint(), nil))
		}
		for i, input := range inputs {
			// Errors don't matter here, as we only consider the
			// case where len(addrs) == 1.
			_, addrs, _, _ := input.Addresses(activeNet.Params)
			if len(addrs) != 1 {
				continue
			}
			apkh, ok := addrs[0].(*btcutil.AddressPubKeyHash)
			if !ok {
				continue // don't handle inputs to this yes
			}

			ai, err := a.Address(apkh)
			if err != nil {
				return nil, fmt.Errorf("cannot get address info: %v", err)
			}

			pka := ai.(wallet.PubKeyAddress)

			privkey, err := pka.PrivKey()
			if err == wallet.ErrWalletLocked {
				return nil, wallet.ErrWalletLocked
			} else if err != nil {
				return nil, fmt.Errorf("cannot get address key: %v", err)
			}

			sigscript, err := btcscript.SignatureScript(msgtx, i,
				input.TxOut().PkScript, btcscript.SigHashAll, privkey,
				ai.Compressed())
			if err != nil {
				return nil, fmt.Errorf("cannot create sigscript: %s", err)
			}
			msgtx.TxIn[i].SignatureScript = sigscript
		}

		noFeeAllowed := false
		if !cfg.DisallowFree {
			noFeeAllowed = allowFree(bs.Height, inputs, msgtx.SerializeSize())
		}
		if minFee := minimumFee(msgtx, noFeeAllowed); fee < minFee {
			fee = minFee
		} else {
			selectedInputs = inputs
			break
		}
	}

	// Validate msgtx before returning the raw transaction.
	flags := btcscript.ScriptCanonicalSignatures
	bip16 := time.Now().After(btcscript.Bip16Activation)
	if bip16 {
		flags |= btcscript.ScriptBip16
	}
	for i, txin := range msgtx.TxIn {
		engine, err := btcscript.NewScript(txin.SignatureScript,
			selectedInputs[i].TxOut().PkScript, i, msgtx, flags)
		if err != nil {
			return nil, fmt.Errorf("cannot create script engine: %s", err)
		}
		if err = engine.Execute(); err != nil {
			return nil, fmt.Errorf("cannot validate transaction: %s", err)
		}
	}

	buf := bytes.Buffer{}
	buf.Grow(msgtx.SerializeSize())
	if err := msgtx.BtcEncode(&buf, btcwire.ProtocolVersion); err != nil {
		// Hitting OOM by growing or writing to a bytes.Buffer already
		// panics, and all returned errors are unexpected.
		panic(err)
	}
	info := &CreatedTx{
		tx:         btcutil.NewTx(msgtx),
		inputs:     selectedInputs,
		changeAddr: changeAddr,
	}
	return info, nil
}
示例#12
0
// txToPairs creates a raw transaction sending the amounts for each
// address/amount pair and fee to each address and the miner.  minconf
// specifies the minimum number of confirmations required before an
// unspent output is eligible for spending. Leftover input funds not sent
// to addr or as a fee for the miner are sent to a newly generated
// address. If change is needed to return funds back to an owned
// address, changeUtxo will point to a unconfirmed (height = -1, zeroed
// block hash) Utxo.  ErrInsufficientFunds is returned if there are not
// enough eligible unspent outputs to create the transaction.
func (a *Account) txToPairs(pairs map[string]int64, minconf int) (*CreatedTx, error) {
	// Create a new transaction which will include all input scripts.
	msgtx := btcwire.NewMsgTx()

	// Calculate minimum amount needed for inputs.
	var amt int64
	for _, v := range pairs {
		// Error out if any amount is negative.
		if v <= 0 {
			return nil, ErrNonPositiveAmount
		}
		amt += v
	}

	// outputs is a tx.Pair slice representing each output that is created
	// by the transaction.
	outputs := make([]tx.Pair, 0, len(pairs)+1)

	// Add outputs to new tx.
	for addrStr, amt := range pairs {
		addr, err := btcutil.DecodeAddr(addrStr)
		if err != nil {
			return nil, fmt.Errorf("cannot decode address: %s", err)
		}

		// Add output to spend amt to addr.
		pkScript, err := btcscript.PayToAddrScript(addr)
		if err != nil {
			return nil, fmt.Errorf("cannot create txout script: %s", err)
		}
		txout := btcwire.NewTxOut(int64(amt), pkScript)
		msgtx.AddTxOut(txout)

		// Create amount, address pair and add to outputs.
		out := tx.Pair{
			Amount:     amt,
			PubkeyHash: addr.ScriptAddress(),
		}
		outputs = append(outputs, out)
	}

	// Get current block's height and hash.
	bs, err := GetCurBlock()
	if err != nil {
		return nil, err
	}

	// Make a copy of msgtx before any inputs are added.  This will be
	// used as a starting point when trying a fee and starting over with
	// a higher fee if not enough was originally chosen.
	txNoInputs := msgtx.Copy()

	// These are nil/zeroed until a change address is needed, and reused
	// again in case a change utxo has already been chosen.
	var changeAddr *btcutil.AddressPubKeyHash

	var btcspent int64
	var selectedInputs []*tx.Utxo
	var finalChangeUtxo *tx.Utxo

	// Get the number of satoshis to increment fee by when searching for
	// the minimum tx fee needed.
	fee := int64(0)
	for {
		msgtx = txNoInputs.Copy()

		// Select unspent outputs to be used in transaction based on the amount
		// neededing to sent, and the current fee estimation.
		inputs, btcin, err := selectInputs(a.UtxoStore, uint64(amt+fee),
			minconf)
		if err != nil {
			return nil, err
		}

		// Check if there are leftover unspent outputs, and return coins back to
		// a new address we own.
		var changeUtxo *tx.Utxo
		change := btcin - uint64(amt+fee)
		if change > 0 {
			// Create a new address to spend leftover outputs to.

			// Get a new change address if one has not already been found.
			if changeAddr == nil {
				changeAddr, err = a.ChangeAddress(&bs, cfg.KeypoolSize)
				if err != nil {
					return nil, fmt.Errorf("failed to get next address: %s", err)
				}

				// Mark change address as belonging to this account.
				MarkAddressForAccount(changeAddr.EncodeAddress(), a.Name())
			}

			// Spend change.
			pkScript, err := btcscript.PayToAddrScript(changeAddr)
			if err != nil {
				return nil, fmt.Errorf("cannot create txout script: %s", err)
			}
			msgtx.AddTxOut(btcwire.NewTxOut(int64(change), pkScript))

			changeUtxo = &tx.Utxo{
				Amt: change,
				Out: tx.OutPoint{
					// Hash is unset (zeroed) here and must be filled in
					// with the transaction hash of the complete
					// transaction.
					Index: uint32(len(pairs)),
				},
				Height:    -1,
				Subscript: pkScript,
			}
			copy(changeUtxo.AddrHash[:], changeAddr.ScriptAddress())
		}

		// Selected unspent outputs become new transaction's inputs.
		for _, ip := range inputs {
			msgtx.AddTxIn(btcwire.NewTxIn((*btcwire.OutPoint)(&ip.Out), nil))
		}
		for i, ip := range inputs {
			// Error is ignored as the length and network checks can never fail
			// for these inputs.
			addr, _ := btcutil.NewAddressPubKeyHash(ip.AddrHash[:],
				a.Wallet.Net())
			privkey, err := a.AddressKey(addr)
			if err == wallet.ErrWalletLocked {
				return nil, wallet.ErrWalletLocked
			} else if err != nil {
				return nil, fmt.Errorf("cannot get address key: %v", err)
			}
			ai, err := a.AddressInfo(addr)
			if err != nil {
				return nil, fmt.Errorf("cannot get address info: %v", err)
			}

			sigscript, err := btcscript.SignatureScript(msgtx, i,
				ip.Subscript, btcscript.SigHashAll, privkey,
				ai.Compressed)
			if err != nil {
				return nil, fmt.Errorf("cannot create sigscript: %s", err)
			}
			msgtx.TxIn[i].SignatureScript = sigscript
		}

		noFeeAllowed := false
		if !cfg.DisallowFree {
			noFeeAllowed = allowFree(bs.Height, inputs, msgtx.SerializeSize())
		}
		if minFee := minimumFee(msgtx, noFeeAllowed); fee < minFee {
			fee = minFee
		} else {
			// Fill Tx hash of change outpoint with transaction hash.
			if changeUtxo != nil {
				txHash, err := msgtx.TxSha()
				if err != nil {
					return nil, fmt.Errorf("cannot create transaction hash: %s", err)
				}
				copy(changeUtxo.Out.Hash[:], txHash[:])

				// Add change to outputs.
				out := tx.Pair{
					Amount:     int64(change),
					PubkeyHash: changeAddr.ScriptAddress(),
					Change:     true,
				}
				outputs = append(outputs, out)

				finalChangeUtxo = changeUtxo
			}

			selectedInputs = inputs

			btcspent = int64(btcin)

			break
		}
	}

	// Validate msgtx before returning the raw transaction.
	flags := btcscript.ScriptCanonicalSignatures
	bip16 := time.Now().After(btcscript.Bip16Activation)
	if bip16 {
		flags |= btcscript.ScriptBip16
	}
	for i, txin := range msgtx.TxIn {
		engine, err := btcscript.NewScript(txin.SignatureScript,
			selectedInputs[i].Subscript, i, msgtx, flags)
		if err != nil {
			return nil, fmt.Errorf("cannot create script engine: %s", err)
		}
		if err = engine.Execute(); err != nil {
			return nil, fmt.Errorf("cannot validate transaction: %s", err)
		}
	}

	txid, err := msgtx.TxSha()
	if err != nil {
		return nil, fmt.Errorf("cannot create txid for created tx: %v", err)
	}

	buf := new(bytes.Buffer)
	msgtx.BtcEncode(buf, btcwire.ProtocolVersion)
	info := &CreatedTx{
		rawTx:      buf.Bytes(),
		txid:       txid,
		time:       time.Now(),
		inputs:     selectedInputs,
		outputs:    outputs,
		btcspent:   btcspent,
		fee:        fee,
		changeAddr: changeAddr,
		changeUtxo: finalChangeUtxo,
	}
	return info, nil
}