// validateHandler consumes items to validate from the internal validate channel
// and returns the result of the validation on the internal result channel. It
// must be run as a goroutine.
func (v *txValidator) validateHandler() {
out:
for {
select {
case txVI := <-v.validateChan:
// Ensure the referenced input transaction is available.
//txIn := txVI.tx.MsgTx().TxIn[txVI.txInIdx]
txIn := txVI.txIn
txInHash := &txIn.PreviousOutpoint.Hash
originTx, exists := v.txStore[*txInHash]
if !exists || originTx.Err != nil || originTx.Tx == nil {
err := fmt.Errorf("unable to find input "+
"transaction %v referenced from "+
"transaction %v", txInHash,
txVI.tx.Sha())
v.sendResult(err)
break out
}
originMsgTx := originTx.Tx.MsgTx()
// Ensure the output index in the referenced transaction
// is available.
originTxIndex := txIn.PreviousOutpoint.Index
if originTxIndex >= uint32(len(originMsgTx.TxOut)) {
err := fmt.Errorf("out of bounds "+
"input index %d in transaction %v "+
"referenced from transaction %v",
originTxIndex, txInHash, txVI.tx.Sha())
v.sendResult(err)
break out
}
// Create a new script engine for the script pair.
sigScript := txIn.SignatureScript
pkScript := originMsgTx.TxOut[originTxIndex].PkScript
engine, err := btcscript.NewScript(sigScript, pkScript,
txVI.txInIndex, txVI.tx.MsgTx(), v.flags)
if err != nil {
v.sendResult(err)
break out
}
// Execute the script pair.
if err := engine.Execute(); err != nil {
err := fmt.Errorf("validate of input "+
"%d failed: %v", txVI.txInIndex, err)
v.sendResult(err)
break out
}
// Validation succeeded.
v.sendResult(nil)
case <-v.quitChan:
break out
}
}
}
// Returns the "Author" who signed the first txin of the transaction
func getAuthor(tx *btcwire.MsgTx, net *btcnet.Params) (string, error) {
sigScript := tx.TxIn[0].SignatureScript
dummyTx := btcwire.NewMsgTx()
// Setup a script executor to parse the raw bytes of the signature script.
script, err := btcscript.NewScript(sigScript, make([]byte, 0), 0, dummyTx, 0)
if err != nil {
return "", err
}
// Step twice due to <sig> <pubkey> format of pay 2pubkeyhash
script.Step()
script.Step()
// Pull off the <pubkey>
pkBytes := script.GetStack()[1]
addrPubKey, err := btcutil.NewAddressPubKey(pkBytes, net)
if err != nil {
return "", err
}
return addrPubKey.EncodeAddress(), nil
}
// 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
}
// validateHandler consumes items to validate from the internal validate channel
// and returns the result of the validation on the internal result channel. It
// must be run as a goroutine.
func (v *txValidator) validateHandler() {
out:
for {
select {
case txVI := <-v.validateChan:
// Ensure the referenced input transaction is available.
txIn := txVI.txIn
originTxHash := &txIn.PreviousOutPoint.Hash
originTx, exists := v.txStore[*originTxHash]
if !exists || originTx.Err != nil || originTx.Tx == nil {
str := fmt.Sprintf("unable to find input "+
"transaction %v referenced from "+
"transaction %v", originTxHash,
txVI.tx.Sha())
err := ruleError(ErrMissingTx, str)
v.sendResult(err)
break out
}
originMsgTx := originTx.Tx.MsgTx()
// Ensure the output index in the referenced transaction
// is available.
originTxIndex := txIn.PreviousOutPoint.Index
if originTxIndex >= uint32(len(originMsgTx.TxOut)) {
str := fmt.Sprintf("out of bounds "+
"input index %d in transaction %v "+
"referenced from transaction %v",
originTxIndex, originTxHash,
txVI.tx.Sha())
err := ruleError(ErrBadTxInput, str)
v.sendResult(err)
break out
}
// Create a new script engine for the script pair.
sigScript := txIn.SignatureScript
pkScript := originMsgTx.TxOut[originTxIndex].PkScript
engine, err := btcscript.NewScript(sigScript, pkScript,
txVI.txInIndex, txVI.tx.MsgTx(), v.flags)
if err != nil {
str := fmt.Sprintf("failed to parse input "+
"%s:%d which references output %s:%d - "+
"%v (input script bytes %x, prev output "+
"script bytes %x)", txVI.tx.Sha(),
txVI.txInIndex, originTxHash,
originTxIndex, err, sigScript, pkScript)
err := ruleError(ErrScriptMalformed, str)
v.sendResult(err)
break out
}
// Execute the script pair.
if err := engine.Execute(); err != nil {
str := fmt.Sprintf("failed to validate input "+
"%s:%d which references output %s:%d - "+
"%v (input script bytes %x, prev output "+
"script bytes %x)", txVI.tx.Sha(),
txVI.txInIndex, originTxHash,
originTxIndex, err, sigScript, pkScript)
err := ruleError(ErrScriptValidation, str)
v.sendResult(err)
break out
}
// Validation succeeded.
v.sendResult(nil)
case <-v.quitChan:
break out
}
}
}
// 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
}
// 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
}
func processPubKeyHash(db btcdb.Db, rd *rData) error {
sigScript := rd.txIn.SignatureScript
pkScript := rd.txPrevOut.PkScript
script, err := btcscript.NewScript(sigScript, pkScript, rd.txInIndex, rd.tx.MsgTx(), 0)
if err != nil {
return fmt.Errorf("failed btcscript.NewScript - h %v: %v\n", rd.in.H, err)
}
for script.Next() != btcscript.OP_CHECKSIG {
_, err := script.Step()
if err != nil {
return fmt.Errorf("Failed Step - in %v: %v\n", rd.in, err)
}
}
data := script.GetStack()
rd.sigStr = data[0]
rd.pkStr = data[1]
aPubKey, err := btcutil.NewAddressPubKey(rd.pkStr, &btcnet.MainNetParams)
if err != nil {
return fmt.Errorf("Pubkey parse error: %v", err)
}
rd.address = aPubKey.EncodeAddress()
rd.compressed = aPubKey.Format() == btcutil.PKFCompressed
// From github.com/conformal/btcscript/opcode.go
// Signature actually needs needs to be longer than this, but we need
// at least 1 byte for the below. btcec will check full length upon
// parsing the signature.
if len(rd.sigStr) < 1 {
return fmt.Errorf("OP_CHECKSIG ERROR")
}
// Trim off hashtype from the signature string.
hashType := rd.sigStr[len(rd.sigStr)-1]
sigStr := rd.sigStr[:len(rd.sigStr)-1]
// Get script from the last OP_CODESEPARATOR and without any subsequent
// OP_CODESEPARATORs
subScript := script.SubScript()
// Unlikely to hit any cases here, but remove the signature from
// the script if present.
subScript = btcscript.RemoveOpcodeByData(subScript, sigStr)
hash := btcscript.CalcScriptHash(subScript, hashType, rd.tx.MsgTx(), rd.txInIndex)
pubKey, err := btcec.ParsePubKey(rd.pkStr, btcec.S256())
if err != nil {
return fmt.Errorf("OP_CHECKSIG ERROR")
}
signature, err := btcec.ParseSignature(sigStr, btcec.S256())
if err != nil {
return fmt.Errorf("OP_CHECKSIG ERROR")
}
// log.Printf("op_checksig\n"+
// "pubKey:\n%v"+
// "pubKey.X: %v\n"+
// "pubKey.Y: %v\n"+
// "signature.R: %v\n"+
// "signature.S: %v\n"+
// "checkScriptHash:\n%v",
// hex.Dump(pkStr), pubKey.X, pubKey.Y,
// signature.R, signature.S, hex.Dump(hash))
if ok := ecdsa.Verify(pubKey.ToECDSA(), hash, signature.R, signature.S); !ok {
return fmt.Errorf("OP_CHECKSIG FAIL")
}
rd.signature = signature
rd.pubKey = pubKey
rd.hash = hash
return nil
}