Golang crypto.NewTree函數代碼示例

func (r *Renter) newHostUploader(settings modules.HostSettings, filesize uint64, duration types.BlockHeight, masterKey crypto.TwofishKey) (*hostUploader, error) {
	hu := &hostUploader{
		settings:  settings,
		masterKey: masterKey,
		tree:      crypto.NewTree(),
		renter:    r,
	}

	// TODO: maybe do this later?
	err := hu.negotiateContract(filesize, duration)
	if err != nil {
		return nil, err
	}

	// initiate the revision loop
	hu.conn, err = net.DialTimeout("tcp", string(hu.settings.IPAddress), 15*time.Second)
	if err != nil {
		return nil, err
	}
	if err := encoding.WriteObject(hu.conn, modules.RPCRevise); err != nil {
		return nil, err
	}
	if err := encoding.WriteObject(hu.conn, hu.contract.ID); err != nil {
		return nil, err
	}

	return hu, nil
}

// newHostUploader initiates the contract revision process with a host, and
// returns a hostUploader, which satisfies the Uploader interface.
func (hdb *HostDB) newHostUploader(hc hostContract) (*hostUploader, error) {
	hdb.mu.RLock()
	settings, ok := hdb.allHosts[hc.IP] // or activeHosts?
	hdb.mu.RUnlock()
	if !ok {
		return nil, errors.New("no record of that host")
	}
	// TODO: check for excessive price again?

	// initiate revision loop
	conn, err := net.DialTimeout("tcp", string(hc.IP), 15*time.Second)
	if err != nil {
		return nil, err
	}
	if err := encoding.WriteObject(conn, modules.RPCRevise); err != nil {
		return nil, err
	}
	if err := encoding.WriteObject(conn, hc.ID); err != nil {
		return nil, err
	}
	// TODO: some sort of acceptance would be good here, so that we know the
	// uploader will actually work. Maybe send the Merkle root?

	hu := &hostUploader{
		contract: hc,
		price:    settings.Price,

		tree: crypto.NewTree(),

		conn: conn,
		hdb:  hdb,
	}

	return hu, nil
}

// UnlockHash calculates the root hash of a Merkle tree of the
// UnlockConditions object. The leaves of this tree are formed by taking the
// hash of the timelock, the hash of the public keys (one leaf each), and the
// hash of the number of signatures. The keys are put in the middle because
// Timelock and SignaturesRequired are both low entropy fields; they can be
// protected by having random public keys next to them.
func (uc UnlockConditions) UnlockHash() UnlockHash {
	tree := crypto.NewTree()
	tree.PushObject(uc.Timelock)
	for i := range uc.PublicKeys {
		tree.PushObject(uc.PublicKeys[i])
	}
	tree.PushObject(uc.SignaturesRequired)
	return UnlockHash(tree.Root())
}

// MerkleRoot calculates the Merkle root of a Block. The leaves of the Merkle
// tree are composed of the Timestamp, the miner outputs (one leaf per
// payout), and the transactions (one leaf per transaction).
func (b Block) MerkleRoot() crypto.Hash {
	tree := crypto.NewTree()
	for _, payout := range b.MinerPayouts {
		tree.PushObject(payout)
	}
	for _, txn := range b.Transactions {
		tree.PushObject(txn)
	}
	return tree.Root()
}

// consensusChecksum grabs a checksum of the consensus set by pushing all of
// the elements in sorted order into a merkle tree and taking the root. All
// consensus sets with the same current block should have identical consensus
// checksums.
func consensusChecksum(tx *bolt.Tx) crypto.Hash {
	// Create a checksum tree.
	tree := crypto.NewTree()

	// For all of the constant buckets, push every key and every value. Buckets
	// are sorted in byte-order, therefore this operation is deterministic.
	consensusSetBuckets := []*bolt.Bucket{
		tx.Bucket(BlockPath),
		tx.Bucket(SiacoinOutputs),
		tx.Bucket(FileContracts),
		tx.Bucket(SiafundOutputs),
		tx.Bucket(SiafundPool),
	}
	for i := range consensusSetBuckets {
		err := consensusSetBuckets[i].ForEach(func(k, v []byte) error {
			tree.Push(k)
			tree.Push(v)
			return nil
		})
		if err != nil {
			manageErr(tx, err)
		}
	}

	// Iterate through all the buckets looking for buckets prefixed with
	// prefixDSCO or prefixFCEX. Buckets are presented in byte-sorted order by
	// name.
	err := tx.ForEach(func(name []byte, b *bolt.Bucket) error {
		// If the bucket is not a delayed siacoin output bucket or a file
		// contract expiration bucket, skip.
		if !bytes.HasPrefix(name, prefixDSCO) && !bytes.HasPrefix(name, prefixFCEX) {
			return nil
		}

		// The bucket is a prefixed bucket - add all elements to the tree.
		return b.ForEach(func(k, v []byte) error {
			tree.Push(k)
			tree.Push(v)
			return nil
		})
	})
	if err != nil {
		manageErr(tx, err)
	}

	return tree.Root()
}

// newHostUploader negotiates an initial file contract with the specified host
// and returns a hostUploader, which satisfies the uploader interface.
func (r *Renter) newHostUploader(settings modules.HostSettings, filesize uint64, duration types.BlockHeight, masterKey crypto.TwofishKey) (*hostUploader, error) {
	// reject hosts that are too expensive
	if settings.Price.Cmp(maxPrice) > 0 {
		return nil, errTooExpensive
	}

	hu := &hostUploader{
		settings:  settings,
		masterKey: masterKey,
		tree:      crypto.NewTree(),
		renter:    r,
	}

	// get an address to use for negotiation
	// TODO: use more than one shared address
	if r.cachedAddress == (types.UnlockHash{}) {
		uc, err := r.wallet.NextAddress()
		if err != nil {
			return nil, err
		}
		r.cachedAddress = uc.UnlockHash()
	}

	// TODO: check for existing contract?
	err := hu.negotiateContract(filesize, duration, r.cachedAddress)
	if err != nil {
		return nil, err
	}

	// if negotiation was sucessful, clear the cached address
	r.cachedAddress = types.UnlockHash{}

	// initiate the revision loop
	hu.conn, err = net.DialTimeout("tcp", string(hu.settings.IPAddress), 15*time.Second)
	if err != nil {
		return nil, err
	}
	if err := encoding.WriteObject(hu.conn, modules.RPCRevise); err != nil {
		return nil, err
	}
	if err := encoding.WriteObject(hu.conn, hu.contract.ID); err != nil {
		return nil, err
	}

	return hu, nil
}

// managedRPCRevise is an RPC that allows a renter to revise a file contract. It will
// read new revisions in a loop until the renter sends a termination signal.
func (h *Host) managedRPCRevise(conn net.Conn) error {
	// read ID of contract to be revised
	var fcid types.FileContractID
	if err := encoding.ReadObject(conn, &fcid, crypto.HashSize); err != nil {
		return errors.New("couldn't read contract ID: " + err.Error())
	}

	// remove conn deadline while we wait for lock and rebuild the Merkle tree.
	err := conn.SetDeadline(time.Now().Add(15 * time.Minute))
	if err != nil {
		return err
	}

	h.mu.RLock()
	obligation, exists := h.obligationsByID[fcid]
	h.mu.RUnlock()
	if !exists {
		return errors.New("no record of that contract")
	}
	// need to protect against two simultaneous revisions to the same
	// contract; this can cause inconsistency and data loss, making storage
	// proofs impossible
	//
	// TODO: DOS vector - the host has locked the obligation even though the
	// renter has not proven themselves to be the owner of the file contract.
	obligation.mu.Lock()
	defer obligation.mu.Unlock()

	// open the file in append mode
	file, err := os.OpenFile(obligation.Path, os.O_CREATE|os.O_RDWR|os.O_APPEND, 0660)
	if err != nil {
		return err
	}

	// rebuild current Merkle tree
	tree := crypto.NewTree()
	err = tree.ReadSegments(file)
	if err != nil {
		// Error does not need to be checked when closing the file, already
		// there have been issues related to the filesystem.
		_ = file.Close()
		return err
	}

	// accept new revisions in a loop. The final good transaction will be
	// submitted to the blockchain.
	revisionErr := func() error {
		for {
			// allow 5 minutes between revisions
			err := conn.SetDeadline(time.Now().Add(5 * time.Minute))
			if err != nil {
				return err
			}

			// read proposed revision
			var revTxn types.Transaction
			if err = encoding.ReadObject(conn, &revTxn, types.BlockSizeLimit); err != nil {
				return errors.New("couldn't read revision: " + err.Error())
			}
			// an empty transaction indicates completion
			if revTxn.ID() == (types.Transaction{}).ID() {
				return nil
			}

			// allow 5 minutes for each revision
			err = conn.SetDeadline(time.Now().Add(5 * time.Minute))
			if err != nil {
				return err
			}

			// check revision against original file contract
			h.mu.RLock()
			err = h.considerRevision(revTxn, obligation)
			h.mu.RUnlock()
			if err != nil {
				// There is nothing that can be done if there is an error while
				// writing to a connection.
				_ = encoding.WriteObject(conn, err.Error())
				return err
			}

			// indicate acceptance
			if err := encoding.WriteObject(conn, modules.AcceptResponse); err != nil {
				return errors.New("couldn't write acceptance: " + err.Error())
			}

			// read piece
			// TODO: simultaneously read into tree and file
			rev := revTxn.FileContractRevisions[0]
			piece := make([]byte, rev.NewFileSize-obligation.fileSize())
			_, err = io.ReadFull(conn, piece)
			if err != nil {
				return errors.New("couldn't read piece data: " + err.Error())
			}

			// verify Merkle root
			err = tree.ReadSegments(bytes.NewReader(piece))
			if err != nil {
//.........這裏部分代碼省略.........

// consensusSetHash returns the Merkle root of the current state of consensus.
func (cs *ConsensusSet) consensusSetHash() crypto.Hash {
	// Check is too slow to be done on a full node.
	if build.Release == "standard" {
		return crypto.Hash{}
	}

	// Items of interest:
	// 1.	genesis block
	// 3.	current height
	// 4.	current target
	// 5.	current depth
	// 6.	current path + diffs
	// (7)	earliest allowed timestamp of next block
	// 8.	unspent siacoin outputs, sorted by id.
	// 9.	open file contracts, sorted by id.
	// 10.	unspent siafund outputs, sorted by id.
	// 11.	delayed siacoin outputs, sorted by height, then sorted by id.
	// 12.	siafund pool

	// Create a slice of hashes representing all items of interest.
	tree := crypto.NewTree()
	tree.PushObject(cs.blockRoot.Block)
	tree.PushObject(cs.height())
	tree.PushObject(cs.currentProcessedBlock().ChildTarget)
	tree.PushObject(cs.currentProcessedBlock().Depth)
	// tree.PushObject(cs.earliestChildTimestamp(cs.currentProcessedBlock()))

	// Add all the blocks in the current path TODO: along with their diffs.
	for i := 0; i < int(cs.db.pathHeight()); i++ {
		tree.PushObject(cs.db.getPath(types.BlockHeight(i)))
	}

	// Add all of the siacoin outputs, sorted by id.
	var openSiacoinOutputs crypto.HashSlice
	cs.db.forEachSiacoinOutputs(func(scoid types.SiacoinOutputID, sco types.SiacoinOutput) {
		openSiacoinOutputs = append(openSiacoinOutputs, crypto.Hash(scoid))
	})
	sort.Sort(openSiacoinOutputs)
	for _, id := range openSiacoinOutputs {
		sco := cs.db.getSiacoinOutputs(types.SiacoinOutputID(id))
		tree.PushObject(id)
		tree.PushObject(sco)
	}

	// Add all of the file contracts, sorted by id.
	var openFileContracts crypto.HashSlice
	cs.db.forEachFileContracts(func(fcid types.FileContractID, fc types.FileContract) {
		openFileContracts = append(openFileContracts, crypto.Hash(fcid))
	})
	sort.Sort(openFileContracts)
	for _, id := range openFileContracts {
		// Sanity Check - file contract should exist.
		fc := cs.db.getFileContracts(types.FileContractID(id))
		tree.PushObject(id)
		tree.PushObject(fc)
	}

	// Add all of the siafund outputs, sorted by id.
	var openSiafundOutputs crypto.HashSlice
	cs.db.forEachSiafundOutputs(func(sfoid types.SiafundOutputID, sfo types.SiafundOutput) {
		openSiafundOutputs = append(openSiafundOutputs, crypto.Hash(sfoid))
	})
	sort.Sort(openSiafundOutputs)
	for _, id := range openSiafundOutputs {
		sco := cs.db.getSiafundOutputs(types.SiafundOutputID(id))
		tree.PushObject(id)
		tree.PushObject(sco)
	}

	// Get the set of delayed siacoin outputs, sorted by maturity height then
	// sorted by id and add them.
	for i := cs.height() + 1; i <= cs.height()+types.MaturityDelay; i++ {
		var delayedSiacoinOutputs crypto.HashSlice
		if cs.db.inDelayedSiacoinOutputs(i) {
			cs.db.forEachDelayedSiacoinOutputsHeight(i, func(id types.SiacoinOutputID, output types.SiacoinOutput) {
				delayedSiacoinOutputs = append(delayedSiacoinOutputs, crypto.Hash(id))
			})
		}
		sort.Sort(delayedSiacoinOutputs)
		for _, delayedSiacoinOutputID := range delayedSiacoinOutputs {
			delayedSiacoinOutput := cs.db.getDelayedSiacoinOutputs(i, types.SiacoinOutputID(delayedSiacoinOutputID))
			tree.PushObject(delayedSiacoinOutput)
			tree.PushObject(delayedSiacoinOutputID)
		}
	}

	// Add the siafund pool
	var siafundPool types.Currency
	err := cs.db.Update(func(tx *bolt.Tx) error {
		siafundPool = getSiafundPool(tx)
		return nil
	})
	if err != nil {
		panic(err)
	}
	tree.PushObject(siafundPool)

	return tree.Root()
}

// consensusSetHash returns the Merkle root of the current state of consensus.
func (cs *State) consensusSetHash() crypto.Hash {
	// Items of interest:
	// 1.	genesis block
	// 3.	current height
	// 4.	current target
	// 5.	current depth
	// 6.	earliest allowed timestamp of next block
	// 7.	current path, ordered by height.
	// 8.	unspent siacoin outputs, sorted by id.
	// 9.	open file contracts, sorted by id.
	// 10.	unspent siafund outputs, sorted by id.
	// 11.	delayed siacoin outputs, sorted by height, then sorted by id.
	// TODO: Add the diff set ?

	// Create a slice of hashes representing all items of interest.
	tree := crypto.NewTree()
	tree.PushObject(cs.blockRoot.block)
	tree.PushObject(cs.height())
	tree.PushObject(cs.currentBlockNode().childTarget)
	tree.PushObject(cs.currentBlockNode().depth)
	tree.PushObject(cs.currentBlockNode().earliestChildTimestamp())

	// Add all the blocks in the current path.
	for i := 0; i < len(cs.currentPath); i++ {
		tree.PushObject(cs.currentPath[types.BlockHeight(i)])
	}

	// Add all of the siacoin outputs, sorted by id.
	var openSiacoinOutputs crypto.HashSlice
	for siacoinOutputID, _ := range cs.siacoinOutputs {
		openSiacoinOutputs = append(openSiacoinOutputs, crypto.Hash(siacoinOutputID))
	}
	sort.Sort(openSiacoinOutputs)
	for _, id := range openSiacoinOutputs {
		sco, exists := cs.siacoinOutputs[types.SiacoinOutputID(id)]
		if !exists {
			panic("trying to push nonexistent siacoin output")
		}
		tree.PushObject(id)
		tree.PushObject(sco)
	}

	// Add all of the file contracts, sorted by id.
	var openFileContracts crypto.HashSlice
	for fileContractID, _ := range cs.fileContracts {
		openFileContracts = append(openFileContracts, crypto.Hash(fileContractID))
	}
	sort.Sort(openFileContracts)
	for _, id := range openFileContracts {
		// Sanity Check - file contract should exist.
		fc, exists := cs.fileContracts[types.FileContractID(id)]
		if !exists {
			panic("trying to push a nonexistent file contract")
		}
		tree.PushObject(id)
		tree.PushObject(fc)
	}

	// Add all of the siafund outputs, sorted by id.
	var openSiafundOutputs crypto.HashSlice
	for siafundOutputID, _ := range cs.siafundOutputs {
		openSiafundOutputs = append(openSiafundOutputs, crypto.Hash(siafundOutputID))
	}
	sort.Sort(openSiafundOutputs)
	for _, id := range openSiafundOutputs {
		sco, exists := cs.siafundOutputs[types.SiafundOutputID(id)]
		if !exists {
			panic("trying to push nonexistent siafund output")
		}
		tree.PushObject(id)
		tree.PushObject(sco)
	}

	// Get the set of delayed siacoin outputs, sorted by maturity height then
	// sorted by id and add them.
	for i := cs.height() + 1; i <= cs.height()+types.MaturityDelay; i++ {
		var delayedSiacoinOutputs crypto.HashSlice
		for id := range cs.delayedSiacoinOutputs[i] {
			delayedSiacoinOutputs = append(delayedSiacoinOutputs, crypto.Hash(id))
		}
		sort.Sort(delayedSiacoinOutputs)

		for _, delayedSiacoinOutputID := range delayedSiacoinOutputs {
			delayedSiacoinOutput, exists := cs.delayedSiacoinOutputs[i][types.SiacoinOutputID(delayedSiacoinOutputID)]
			if !exists {
				panic("trying to push nonexistent delayed siacoin output")
			}
			tree.PushObject(delayedSiacoinOutput)
			tree.PushObject(delayedSiacoinOutputID)
		}
	}

	return tree.Root()
}

// rpcRevise is an RPC that allows a renter to revise a file contract. It will
// read new revisions in a loop until the renter sends a termination signal.
func (h *Host) rpcRevise(conn net.Conn) error {
	// read ID of contract to be revised
	var fcid types.FileContractID
	if err := encoding.ReadObject(conn, &fcid, crypto.HashSize); err != nil {
		return err
	}
	lockID := h.mu.RLock()
	obligation, exists := h.obligationsByID[fcid]
	h.mu.RUnlock(lockID)
	if !exists {
		return errors.New("no record of that contract")
	}

	// need to protect against two simultaneous revisions to the same
	// contract; this can cause inconsistency and data loss, making storage
	// proofs impossible
	obligation.mu.Lock()
	defer obligation.mu.Unlock()

	// open the file in append mode
	file, err := os.OpenFile(obligation.Path, os.O_CREATE|os.O_RDWR|os.O_APPEND, 0660)
	if err != nil {
		return err
	}
	defer func() {
		// if a newly-created file was not updated, remove it
		if stat, _ := file.Stat(); stat.Size() == 0 {
			os.Remove(obligation.Path)
		}
		file.Close()
	}()

	// rebuild current Merkle tree
	tree := crypto.NewTree()
	buf := make([]byte, crypto.SegmentSize)
	for {
		_, err := io.ReadFull(file, buf)
		if err == io.EOF {
			break
		} else if err != nil && err != io.ErrUnexpectedEOF {
			return err
		}
		tree.Push(buf)
	}

	// accept new revisions in a loop. The final good transaction will be
	// submitted to the blockchain.
	var finalTxn types.Transaction
	defer func() {
		h.tpool.AcceptTransactionSet([]types.Transaction{finalTxn})
	}()
	for {
		// read proposed revision
		var revTxn types.Transaction
		if err := encoding.ReadObject(conn, &revTxn, types.BlockSizeLimit); err != nil {
			return err
		}
		// an empty transaction indicates completion
		if revTxn.ID() == (types.Transaction{}).ID() {
			break
		}

		// check revision against original file contract
		lockID = h.mu.RLock()
		err := h.considerRevision(revTxn, obligation)
		h.mu.RUnlock(lockID)
		if err != nil {
			encoding.WriteObject(conn, err.Error())
			continue // don't terminate loop; subsequent revisions may be okay
		}

		// indicate acceptance
		if err := encoding.WriteObject(conn, modules.AcceptResponse); err != nil {
			return err
		}

		// read piece
		// TODO: simultaneously read into tree?
		rev := revTxn.FileContractRevisions[0]
		piece := make([]byte, rev.NewFileSize-obligation.FileContract.FileSize)
		_, err = io.ReadFull(conn, piece)
		if err != nil {
			return err
		}

		// verify Merkle root
		r := bytes.NewReader(piece)
		for {
			_, err := io.ReadFull(r, buf)
			if err == io.EOF {
				break
			} else if err != nil && err != io.ErrUnexpectedEOF {
				return err
			}
			tree.Push(buf)
		}
		if tree.Root() != rev.NewFileMerkleRoot {
			return errors.New("revision has bad Merkle root")
//.........這裏部分代碼省略.........

// rpcRevise is an RPC that allows a renter to revise a file contract. It will
// read new revisions in a loop until the renter sends a termination signal.
func (h *Host) rpcRevise(conn net.Conn) error {
	// read ID of contract to be revised
	var fcid types.FileContractID
	if err := encoding.ReadObject(conn, &fcid, crypto.HashSize); err != nil {
		return errors.New("couldn't read contract ID: " + err.Error())
	}

	// remove conn deadline while we wait for lock and rebuild the Merkle tree
	conn.SetDeadline(time.Time{})

	h.mu.RLock()
	obligation, exists := h.obligationsByID[fcid]
	h.mu.RUnlock()
	if !exists {
		return errors.New("no record of that contract")
	}

	// need to protect against two simultaneous revisions to the same
	// contract; this can cause inconsistency and data loss, making storage
	// proofs impossible
	obligation.mu.Lock()
	defer obligation.mu.Unlock()

	// open the file in append mode
	file, err := os.OpenFile(obligation.Path, os.O_CREATE|os.O_RDWR|os.O_APPEND, 0660)
	if err != nil {
		return err
	}

	// rebuild current Merkle tree
	tree := crypto.NewTree()
	err = tree.ReadSegments(file)
	if err != nil {
		file.Close()
		return err
	}

	// accept new revisions in a loop. The final good transaction will be
	// submitted to the blockchain.
	revisionErr := func() error {
		for {
			// allow 2 minutes between revisions
			conn.SetDeadline(time.Now().Add(2 * time.Minute))

			// read proposed revision
			var revTxn types.Transaction
			if err := encoding.ReadObject(conn, &revTxn, types.BlockSizeLimit); err != nil {
				return errors.New("couldn't read revision: " + err.Error())
			}
			// an empty transaction indicates completion
			if revTxn.ID() == (types.Transaction{}).ID() {
				return nil
			}

			// allow 5 minutes for each revision
			conn.SetDeadline(time.Now().Add(5 * time.Minute))

			// check revision against original file contract
			h.mu.RLock()
			err := h.considerRevision(revTxn, *obligation)
			h.mu.RUnlock()
			if err != nil {
				encoding.WriteObject(conn, err.Error())
				continue // don't terminate loop; subsequent revisions may be okay
			}

			// indicate acceptance
			if err := encoding.WriteObject(conn, modules.AcceptResponse); err != nil {
				return errors.New("couldn't write acceptance: " + err.Error())
			}

			// read piece
			// TODO: simultaneously read into tree and file
			rev := revTxn.FileContractRevisions[0]
			last := obligation.LastRevisionTxn.FileContractRevisions[0]
			piece := make([]byte, rev.NewFileSize-last.NewFileSize)
			_, err = io.ReadFull(conn, piece)
			if err != nil {
				return errors.New("couldn't read piece data: " + err.Error())
			}

			// verify Merkle root
			err = tree.ReadSegments(bytes.NewReader(piece))
			if err != nil {
				return errors.New("couldn't verify Merkle root: " + err.Error())
			}
			if tree.Root() != rev.NewFileMerkleRoot {
				return errors.New("revision has bad Merkle root")
			}

			// manually sign the transaction
			revTxn.TransactionSignatures = append(revTxn.TransactionSignatures, types.TransactionSignature{
				ParentID:       crypto.Hash(fcid),
				CoveredFields:  types.CoveredFields{FileContractRevisions: []uint64{0}},
				PublicKeyIndex: 1, // host key is always second
			})
			encodedSig, err := crypto.SignHash(revTxn.SigHash(1), h.secretKey)
			if err != nil {
//.........這裏部分代碼省略.........