Golang btcutil.Tx类代码示例

// ExtractCoinbaseHeight attempts to extract the height of the block from the
// scriptSig of a coinbase transaction.  Coinbase heights are only present in
// blocks of version 2 or later.  This was added as part of BIP0034.
func ExtractCoinbaseHeight(coinbaseTx *btcutil.Tx) (int32, error) {
	sigScript := coinbaseTx.MsgTx().TxIn[0].SignatureScript
	if len(sigScript) < 1 {
		str := "the coinbase signature script for blocks of " +
			"version %d or greater must start with the " +
			"length of the serialized block height"
		str = fmt.Sprintf(str, serializedHeightVersion)
		return 0, ruleError(ErrMissingCoinbaseHeight, str)
	}

	serializedLen := int(sigScript[0])
	if len(sigScript[1:]) < serializedLen {
		str := "the coinbase signature script for blocks of " +
			"version %d or greater must start with the " +
			"serialized block height"
		str = fmt.Sprintf(str, serializedLen)
		return 0, ruleError(ErrMissingCoinbaseHeight, str)
	}

	serializedHeightBytes := make([]byte, 8, 8)
	copy(serializedHeightBytes, sigScript[1:serializedLen+1])
	serializedHeight := binary.LittleEndian.Uint64(serializedHeightBytes)

	return int32(serializedHeight), nil
}

// ValidateTransactionScripts validates the scripts for the passed transaction
// using multiple goroutines.
func ValidateTransactionScripts(tx *btcutil.Tx, txStore TxStore, flags txscript.ScriptFlags) error {
	// Collect all of the transaction inputs and required information for
	// validation.
	txIns := tx.MsgTx().TxIn
	txValItems := make([]*txValidateItem, 0, len(txIns))
	for txInIdx, txIn := range txIns {
		// Skip coinbases.
		if txIn.PreviousOutPoint.Index == math.MaxUint32 {
			continue
		}

		txVI := &txValidateItem{
			txInIndex: txInIdx,
			txIn:      txIn,
			tx:        tx,
		}
		txValItems = append(txValItems, txVI)
	}

	// Validate all of the inputs.
	validator := newTxValidator(txStore, flags)
	if err := validator.Validate(txValItems); err != nil {
		return err
	}

	return nil
}

// IsFinalizedTransaction determines whether or not a transaction is finalized.
func IsFinalizedTransaction(tx *btcutil.Tx, blockHeight int32, blockTime time.Time) bool {
	msgTx := tx.MsgTx()

	// Lock time of zero means the transaction is finalized.
	lockTime := msgTx.LockTime
	if lockTime == 0 {
		return true
	}

	// The lock time field of a transaction is either a block height at
	// which the transaction is finalized or a timestamp depending on if the
	// value is before the txscript.LockTimeThreshold.  When it is under the
	// threshold it is a block height.
	blockTimeOrHeight := int64(0)
	if lockTime < txscript.LockTimeThreshold {
		blockTimeOrHeight = int64(blockHeight)
	} else {
		blockTimeOrHeight = blockTime.Unix()
	}
	if int64(lockTime) < blockTimeOrHeight {
		return true
	}

	// At this point, the transaction's lock time hasn't occured yet, but
	// the transaction might still be finalized if the sequence number
	// for all transaction inputs is maxed out.
	for _, txIn := range msgTx.TxIn {
		if txIn.Sequence != math.MaxUint32 {
			return false
		}
	}
	return true
}

// logSkippedDeps logs any dependencies which are also skipped as a result of
// skipping a transaction while generating a block template at the trace level.
func logSkippedDeps(tx *btcutil.Tx, deps *list.List) {
	if deps == nil {
		return
	}

	for e := deps.Front(); e != nil; e = e.Next() {
		item := e.Value.(*txPrioItem)
		minrLog.Tracef("Skipping tx %s since it depends on %s\n",
			item.tx.Sha(), tx.Sha())
	}
}

// isNonstandardTransaction determines whether a transaction contains any
// scripts which are not one of the standard types.
func isNonstandardTransaction(tx *btcutil.Tx) bool {
	// TODO(davec): Should there be checks for the input signature scripts?

	// Check all of the output public key scripts for non-standard scripts.
	for _, txOut := range tx.MsgTx().TxOut {
		scriptClass := txscript.GetScriptClass(txOut.PkScript)
		if scriptClass == txscript.NonStandardTy {
			return true
		}
	}
	return false
}

// matchTxAndUpdate returns true if the bloom filter matches data within the
// passed transaction, otherwise false is returned.  If the filter does match
// the passed transaction, it will also update the filter depending on the bloom
// update flags set via the loaded filter if needed.
//
// This function MUST be called with the filter lock held.
func (bf *Filter) matchTxAndUpdate(tx *btcutil.Tx) bool {
	// Check if the filter matches the hash of the transaction.
	// This is useful for finding transactions when they appear in a block.
	matched := bf.matches(tx.Sha().Bytes())

	// Check if the filter matches any data elements in the public key
	// scripts of any of the outputs.  When it does, add the outpoint that
	// matched so transactions which spend from the matched transaction are
	// also included in the filter.  This removes the burden of updating the
	// filter for this scenario from the client.  It is also more efficient
	// on the network since it avoids the need for another filteradd message
	// from the client and avoids some potential races that could otherwise
	// occur.
	for i, txOut := range tx.MsgTx().TxOut {
		pushedData, err := txscript.PushedData(txOut.PkScript)
		if err != nil {
			continue
		}

		for _, data := range pushedData {
			if !bf.matches(data) {
				continue
			}

			matched = true
			bf.maybeAddOutpoint(txOut.PkScript, tx.Sha(), uint32(i))
			break
		}
	}

	// Nothing more to do if a match has already been made.
	if matched {
		return true
	}

	// At this point, the transaction and none of the data elements in the
	// public key scripts of its outputs matched.

	// Check if the filter matches any outpoints this transaction spends or
	// any any data elements in the signature scripts of any of the inputs.
	for _, txin := range tx.MsgTx().TxIn {
		if bf.matchesOutPoint(&txin.PreviousOutPoint) {
			return true
		}

		pushedData, err := txscript.PushedData(txin.SignatureScript)
		if err != nil {
			continue
		}
		for _, data := range pushedData {
			if bf.matches(data) {
				return true
			}
		}
	}

	return false
}

// FetchTransactionStore fetches the input transactions referenced by the
// passed transaction from the point of view of the end of the main chain.  It
// also attempts to fetch the transaction itself so the returned TxStore can be
// examined for duplicate transactions.
func (b *BlockChain) FetchTransactionStore(tx *btcutil.Tx, includeSpent bool) (TxStore, error) {
	// Create a set of needed transactions from the transactions referenced
	// by the inputs of the passed transaction.  Also, add the passed
	// transaction itself as a way for the caller to detect duplicates.
	txNeededSet := make(map[wire.ShaHash]struct{})
	txNeededSet[*tx.Sha()] = struct{}{}
	for _, txIn := range tx.MsgTx().TxIn {
		txNeededSet[txIn.PreviousOutPoint.Hash] = struct{}{}
	}

	// Request the input transactions from the point of view of the end of
	// the main chain with or without without including fully spent transactions
	// in the results.
	txStore := fetchTxStoreMain(b.db, txNeededSet, includeSpent)
	return txStore, nil
}

// CountSigOps returns the number of signature operations for all transaction
// input and output scripts in the provided transaction.  This uses the
// quicker, but imprecise, signature operation counting mechanism from
// txscript.
func CountSigOps(tx *btcutil.Tx) int {
	msgTx := tx.MsgTx()

	// Accumulate the number of signature operations in all transaction
	// inputs.
	totalSigOps := 0
	for _, txIn := range msgTx.TxIn {
		numSigOps := txscript.GetSigOpCount(txIn.SignatureScript)
		totalSigOps += numSigOps
	}

	// Accumulate the number of signature operations in all transaction
	// outputs.
	for _, txOut := range msgTx.TxOut {
		numSigOps := txscript.GetSigOpCount(txOut.PkScript)
		totalSigOps += numSigOps
	}

	return totalSigOps
}

// CountP2SHSigOps returns the number of signature operations for all input
// transactions which are of the pay-to-script-hash type.  This uses the
// precise, signature operation counting mechanism from the script engine which
// requires access to the input transaction scripts.
func CountP2SHSigOps(tx *btcutil.Tx, isCoinBaseTx bool, txStore TxStore) (int, error) {
	// Coinbase transactions have no interesting inputs.
	if isCoinBaseTx {
		return 0, nil
	}

	// Accumulate the number of signature operations in all transaction
	// inputs.
	msgTx := tx.MsgTx()
	totalSigOps := 0
	for _, txIn := range msgTx.TxIn {
		// Ensure the referenced input transaction is available.
		txInHash := &txIn.PreviousOutPoint.Hash
		originTx, exists := txStore[*txInHash]
		if !exists || originTx.Err != nil || originTx.Tx == nil {
			str := fmt.Sprintf("unable to find input transaction "+
				"%v referenced from transaction %v", txInHash,
				tx.Sha())
			return 0, ruleError(ErrMissingTx, str)
		}
		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, txInHash, tx.Sha())
			return 0, ruleError(ErrBadTxInput, str)
		}

		// We're only interested in pay-to-script-hash types, so skip
		// this input if it's not one.
		pkScript := originMsgTx.TxOut[originTxIndex].PkScript
		if !txscript.IsPayToScriptHash(pkScript) {
			continue
		}

		// Count the precise number of signature operations in the
		// referenced public key script.
		sigScript := txIn.SignatureScript
		numSigOps := txscript.GetPreciseSigOpCount(sigScript, pkScript,
			true)

		// We could potentially overflow the accumulator so check for
		// overflow.
		lastSigOps := totalSigOps
		totalSigOps += numSigOps
		if totalSigOps < lastSigOps {
			str := fmt.Sprintf("the public key script from "+
				"output index %d in transaction %v contains "+
				"too many signature operations - overflow",
				originTxIndex, txInHash)
			return 0, ruleError(ErrTooManySigOps, str)
		}
	}

	return totalSigOps, nil
}

// spendTransaction updates the passed transaction store by marking the inputs
// to the passed transaction as spent.  It also adds the passed transaction to
// the store at the provided height.
func spendTransaction(txStore blockchain.TxStore, tx *btcutil.Tx, height int32) error {
	for _, txIn := range tx.MsgTx().TxIn {
		originHash := &txIn.PreviousOutPoint.Hash
		originIndex := txIn.PreviousOutPoint.Index
		if originTx, exists := txStore[*originHash]; exists {
			originTx.Spent[originIndex] = true
		}
	}

	txStore[*tx.Sha()] = &blockchain.TxData{
		Tx:          tx,
		Hash:        tx.Sha(),
		BlockHeight: height,
		Spent:       make([]bool, len(tx.MsgTx().TxOut)),
		Err:         nil,
	}

	return nil
}

// CheckTransactionInputs performs a series of checks on the inputs to a
// transaction to ensure they are valid.  An example of some of the checks
// include verifying all inputs exist, ensuring the coinbase seasoning
// requirements are met, detecting double spends, validating all values and fees
// are in the legal range and the total output amount doesn't exceed the input
// amount, and verifying the signatures to prove the spender was the owner of
// the bitcoins and therefore allowed to spend them.  As it checks the inputs,
// it also calculates the total fees for the transaction and returns that value.
func CheckTransactionInputs(tx *btcutil.Tx, txHeight int32, txStore TxStore) (int64, error) {
	// Coinbase transactions have no inputs.
	if IsCoinBase(tx) {
		return 0, nil
	}

	txHash := tx.Sha()
	var totalSatoshiIn int64
	for _, txIn := range tx.MsgTx().TxIn {
		// Ensure the input is available.
		txInHash := &txIn.PreviousOutPoint.Hash
		originTx, exists := txStore[*txInHash]
		if !exists || originTx.Err != nil || originTx.Tx == nil {
			str := fmt.Sprintf("unable to find input transaction "+
				"%v for transaction %v", txInHash, txHash)
			return 0, ruleError(ErrMissingTx, str)
		}

		// Ensure the transaction is not spending coins which have not
		// yet reached the required coinbase maturity.
		if IsCoinBase(originTx.Tx) {
			originHeight := originTx.BlockHeight
			blocksSincePrev := txHeight - originHeight
			if blocksSincePrev < coinbaseMaturity {
				str := fmt.Sprintf("tried to spend coinbase "+
					"transaction %v from height %v at "+
					"height %v before required maturity "+
					"of %v blocks", txInHash, originHeight,
					txHeight, coinbaseMaturity)
				return 0, ruleError(ErrImmatureSpend, str)
			}
		}

		// Ensure the transaction is not double spending coins.
		originTxIndex := txIn.PreviousOutPoint.Index
		if originTxIndex >= uint32(len(originTx.Spent)) {
			str := fmt.Sprintf("out of bounds input index %d in "+
				"transaction %v referenced from transaction %v",
				originTxIndex, txInHash, txHash)
			return 0, ruleError(ErrBadTxInput, str)
		}
		if originTx.Spent[originTxIndex] {
			str := fmt.Sprintf("transaction %v tried to double "+
				"spend output %v", txHash, txIn.PreviousOutPoint)
			return 0, ruleError(ErrDoubleSpend, str)
		}

		// Ensure the transaction amounts are in range.  Each of the
		// output values of the input transactions must not be negative
		// or more than the max allowed per transaction.  All amounts in
		// a transaction are in a unit value known as a satoshi.  One
		// bitcoin is a quantity of satoshi as defined by the
		// SatoshiPerBitcoin constant.
		originTxSatoshi := originTx.Tx.MsgTx().TxOut[originTxIndex].Value
		if originTxSatoshi < 0 {
			str := fmt.Sprintf("transaction output has negative "+
				"value of %v", originTxSatoshi)
			return 0, ruleError(ErrBadTxOutValue, str)
		}
		if originTxSatoshi > btcutil.MaxSatoshi {
			str := fmt.Sprintf("transaction output value of %v is "+
				"higher than max allowed value of %v",
				originTxSatoshi, btcutil.MaxSatoshi)
			return 0, ruleError(ErrBadTxOutValue, str)
		}

		// The total of all outputs must not be more than the max
		// allowed per transaction.  Also, we could potentially overflow
		// the accumulator so check for overflow.
		lastSatoshiIn := totalSatoshiIn
		totalSatoshiIn += originTxSatoshi
		if totalSatoshiIn < lastSatoshiIn ||
			totalSatoshiIn > btcutil.MaxSatoshi {
			str := fmt.Sprintf("total value of all transaction "+
				"inputs is %v which is higher than max "+
				"allowed value of %v", totalSatoshiIn,
				btcutil.MaxSatoshi)
			return 0, ruleError(ErrBadTxOutValue, str)
		}

		// Mark the referenced output as spent.
		originTx.Spent[originTxIndex] = true
	}

	// Calculate the total output amount for this transaction.  It is safe
	// to ignore overflow and out of range errors here because those error
	// conditions would have already been caught by checkTransactionSanity.
	var totalSatoshiOut int64
	for _, txOut := range tx.MsgTx().TxOut {
		totalSatoshiOut += txOut.Value
	}

//.........这里部分代码省略.........

// CheckTransactionSanity performs some preliminary checks on a transaction to
// ensure it is sane.  These checks are context free.
func CheckTransactionSanity(tx *btcutil.Tx) error {
	// A transaction must have at least one input.
	msgTx := tx.MsgTx()
	if len(msgTx.TxIn) == 0 {
		return ruleError(ErrNoTxInputs, "transaction has no inputs")
	}

	// A transaction must have at least one output.
	if len(msgTx.TxOut) == 0 {
		return ruleError(ErrNoTxOutputs, "transaction has no outputs")
	}

	// A transaction must not exceed the maximum allowed block payload when
	// serialized.
	serializedTxSize := tx.MsgTx().SerializeSize()
	if serializedTxSize > wire.MaxBlockPayload {
		str := fmt.Sprintf("serialized transaction is too big - got "+
			"%d, max %d", serializedTxSize, wire.MaxBlockPayload)
		return ruleError(ErrTxTooBig, str)
	}

	// Ensure the transaction amounts are in range.  Each transaction
	// output must not be negative or more than the max allowed per
	// transaction.  Also, the total of all outputs must abide by the same
	// restrictions.  All amounts in a transaction are in a unit value known
	// as a satoshi.  One bitcoin is a quantity of satoshi as defined by the
	// SatoshiPerBitcoin constant.
	var totalSatoshi int64
	for _, txOut := range msgTx.TxOut {
		satoshi := txOut.Value
		if satoshi < 0 {
			str := fmt.Sprintf("transaction output has negative "+
				"value of %v", satoshi)
			return ruleError(ErrBadTxOutValue, str)
		}
		if satoshi > btcutil.MaxSatoshi {
			str := fmt.Sprintf("transaction output value of %v is "+
				"higher than max allowed value of %v", satoshi,
				btcutil.MaxSatoshi)
			return ruleError(ErrBadTxOutValue, str)
		}

		// TODO(davec): No need to check < 0 here as satoshi is
		// guaranteed to be positive per the above check.  Also need
		// to add overflow checks.
		totalSatoshi += satoshi
		if totalSatoshi < 0 {
			str := fmt.Sprintf("total value of all transaction "+
				"outputs has negative value of %v", totalSatoshi)
			return ruleError(ErrBadTxOutValue, str)
		}
		if totalSatoshi > btcutil.MaxSatoshi {
			str := fmt.Sprintf("total value of all transaction "+
				"outputs is %v which is higher than max "+
				"allowed value of %v", totalSatoshi,
				btcutil.MaxSatoshi)
			return ruleError(ErrBadTxOutValue, str)
		}
	}

	// Check for duplicate transaction inputs.
	existingTxOut := make(map[wire.OutPoint]struct{})
	for _, txIn := range msgTx.TxIn {
		if _, exists := existingTxOut[txIn.PreviousOutPoint]; exists {
			return ruleError(ErrDuplicateTxInputs, "transaction "+
				"contains duplicate inputs")
		}
		existingTxOut[txIn.PreviousOutPoint] = struct{}{}
	}

	// Coinbase script length must be between min and max length.
	if IsCoinBase(tx) {
		slen := len(msgTx.TxIn[0].SignatureScript)
		if slen < MinCoinbaseScriptLen || slen > MaxCoinbaseScriptLen {
			str := fmt.Sprintf("coinbase transaction script length "+
				"of %d is out of range (min: %d, max: %d)",
				slen, MinCoinbaseScriptLen, MaxCoinbaseScriptLen)
			return ruleError(ErrBadCoinbaseScriptLen, str)
		}
	} else {
		// Previous transaction outputs referenced by the inputs to this
		// transaction must not be null.
		for _, txIn := range msgTx.TxIn {
			prevOut := &txIn.PreviousOutPoint
			if isNullOutpoint(prevOut) {
				return ruleError(ErrBadTxInput, "transaction "+
					"input refers to previous output that "+
					"is null")
			}
		}
	}

	return nil
}

// IsCoinBase determines whether or not a transaction is a coinbase.  A coinbase
// is a special transaction created by miners that has no inputs.  This is
// represented in the block chain by a transaction with a single input that has
// a previous output transaction index set to the maximum value along with a
// zero hash.
//
// This function only differs from IsCoinBaseTx in that it works with a higher
// level util transaction as opposed to a raw wire transaction.
func IsCoinBase(tx *btcutil.Tx) bool {
	return IsCoinBaseTx(tx.MsgTx())
}