whisper: project restructured, version 5 introduced (#3022)

whisper: project restructured, version 5 introduced

This commits adds a draft version of the new shh v5 protocol.
The new version is not on by default, --shh still selects version 2.

1 files changed, 378 insertions, 0 deletions

diff --git a/whisper/whisperv2/whisper.go b/whisper/whisperv2/whisper.go
new file mode 100644
index 000000000..d9054959e
--- /dev/null
+++ b/whisper/whisperv2/whisper.go
@@ -0,0 +1,378 @@
+// Copyright 2014 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
+
+package whisperv2
+
+import (
+	"crypto/ecdsa"
+	"sync"
+	"time"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/crypto/ecies"
+	"github.com/ethereum/go-ethereum/event/filter"
+	"github.com/ethereum/go-ethereum/logger"
+	"github.com/ethereum/go-ethereum/logger/glog"
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/rpc"
+
+	"gopkg.in/fatih/set.v0"
+)
+
+const (
+	statusCode   = 0x00
+	messagesCode = 0x01
+
+	protocolVersion uint64 = 0x02
+	protocolName           = "shh"
+
+	signatureFlag   = byte(1 << 7)
+	signatureLength = 65
+
+	expirationCycle   = 800 * time.Millisecond
+	transmissionCycle = 300 * time.Millisecond
+)
+
+const (
+	DefaultTTL = 50 * time.Second
+	DefaultPoW = 50 * time.Millisecond
+)
+
+type MessageEvent struct {
+	To      *ecdsa.PrivateKey
+	From    *ecdsa.PublicKey
+	Message *Message
+}
+
+// Whisper represents a dark communication interface through the Ethereum
+// network, using its very own P2P communication layer.
+type Whisper struct {
+	protocol p2p.Protocol
+	filters  *filter.Filters
+
+	keys map[string]*ecdsa.PrivateKey
+
+	messages    map[common.Hash]*Envelope // Pool of messages currently tracked by this node
+	expirations map[uint32]*set.SetNonTS  // Message expiration pool (TODO: something lighter)
+	poolMu      sync.RWMutex              // Mutex to sync the message and expiration pools
+
+	peers  map[*peer]struct{} // Set of currently active peers
+	peerMu sync.RWMutex       // Mutex to sync the active peer set
+
+	quit chan struct{}
+}
+
+// New creates a Whisper client ready to communicate through the Ethereum P2P
+// network.
+func New() *Whisper {
+	whisper := &Whisper{
+		filters:     filter.New(),
+		keys:        make(map[string]*ecdsa.PrivateKey),
+		messages:    make(map[common.Hash]*Envelope),
+		expirations: make(map[uint32]*set.SetNonTS),
+		peers:       make(map[*peer]struct{}),
+		quit:        make(chan struct{}),
+	}
+	whisper.filters.Start()
+
+	// p2p whisper sub protocol handler
+	whisper.protocol = p2p.Protocol{
+		Name:    protocolName,
+		Version: uint(protocolVersion),
+		Length:  2,
+		Run:     whisper.handlePeer,
+	}
+
+	return whisper
+}
+
+// APIs returns the RPC descriptors the Whisper implementation offers
+func (s *Whisper) APIs() []rpc.API {
+	return []rpc.API{
+		{
+			Namespace: "shh",
+			Version:   "1.0",
+			Service:   NewPublicWhisperAPI(s),
+			Public:    true,
+		},
+	}
+}
+
+// Protocols returns the whisper sub-protocols ran by this particular client.
+func (self *Whisper) Protocols() []p2p.Protocol {
+	return []p2p.Protocol{self.protocol}
+}
+
+// Version returns the whisper sub-protocols version number.
+func (self *Whisper) Version() uint {
+	return self.protocol.Version
+}
+
+// NewIdentity generates a new cryptographic identity for the client, and injects
+// it into the known identities for message decryption.
+func (self *Whisper) NewIdentity() *ecdsa.PrivateKey {
+	key, err := crypto.GenerateKey()
+	if err != nil {
+		panic(err)
+	}
+	self.keys[string(crypto.FromECDSAPub(&key.PublicKey))] = key
+
+	return key
+}
+
+// HasIdentity checks if the the whisper node is configured with the private key
+// of the specified public pair.
+func (self *Whisper) HasIdentity(key *ecdsa.PublicKey) bool {
+	return self.keys[string(crypto.FromECDSAPub(key))] != nil
+}
+
+// GetIdentity retrieves the private key of the specified public identity.
+func (self *Whisper) GetIdentity(key *ecdsa.PublicKey) *ecdsa.PrivateKey {
+	return self.keys[string(crypto.FromECDSAPub(key))]
+}
+
+// Watch installs a new message handler to run in case a matching packet arrives
+// from the whisper network.
+func (self *Whisper) Watch(options Filter) int {
+	filter := filterer{
+		to:      string(crypto.FromECDSAPub(options.To)),
+		from:    string(crypto.FromECDSAPub(options.From)),
+		matcher: newTopicMatcher(options.Topics...),
+		fn: func(data interface{}) {
+			options.Fn(data.(*Message))
+		},
+	}
+	return self.filters.Install(filter)
+}
+
+// Unwatch removes an installed message handler.
+func (self *Whisper) Unwatch(id int) {
+	self.filters.Uninstall(id)
+}
+
+// Send injects a message into the whisper send queue, to be distributed in the
+// network in the coming cycles.
+func (self *Whisper) Send(envelope *Envelope) error {
+	return self.add(envelope)
+}
+
+// Start implements node.Service, starting the background data propagation thread
+// of the Whisper protocol.
+func (self *Whisper) Start(*p2p.Server) error {
+	glog.V(logger.Info).Infoln("Whisper started")
+	go self.update()
+	return nil
+}
+
+// Stop implements node.Service, stopping the background data propagation thread
+// of the Whisper protocol.
+func (self *Whisper) Stop() error {
+	close(self.quit)
+	glog.V(logger.Info).Infoln("Whisper stopped")
+	return nil
+}
+
+// Messages retrieves all the currently pooled messages matching a filter id.
+func (self *Whisper) Messages(id int) []*Message {
+	messages := make([]*Message, 0)
+	if filter := self.filters.Get(id); filter != nil {
+		for _, envelope := range self.messages {
+			if message := self.open(envelope); message != nil {
+				if self.filters.Match(filter, createFilter(message, envelope.Topics)) {
+					messages = append(messages, message)
+				}
+			}
+		}
+	}
+	return messages
+}
+
+// handlePeer is called by the underlying P2P layer when the whisper sub-protocol
+// connection is negotiated.
+func (self *Whisper) handlePeer(peer *p2p.Peer, rw p2p.MsgReadWriter) error {
+	// Create the new peer and start tracking it
+	whisperPeer := newPeer(self, peer, rw)
+
+	self.peerMu.Lock()
+	self.peers[whisperPeer] = struct{}{}
+	self.peerMu.Unlock()
+
+	defer func() {
+		self.peerMu.Lock()
+		delete(self.peers, whisperPeer)
+		self.peerMu.Unlock()
+	}()
+
+	// Run the peer handshake and state updates
+	if err := whisperPeer.handshake(); err != nil {
+		return err
+	}
+	whisperPeer.start()
+	defer whisperPeer.stop()
+
+	// Read and process inbound messages directly to merge into client-global state
+	for {
+		// Fetch the next packet and decode the contained envelopes
+		packet, err := rw.ReadMsg()
+		if err != nil {
+			return err
+		}
+		var envelopes []*Envelope
+		if err := packet.Decode(&envelopes); err != nil {
+			glog.V(logger.Info).Infof("%v: failed to decode envelope: %v", peer, err)
+			continue
+		}
+		// Inject all envelopes into the internal pool
+		for _, envelope := range envelopes {
+			if err := self.add(envelope); err != nil {
+				// TODO Punish peer here. Invalid envelope.
+				glog.V(logger.Debug).Infof("%v: failed to pool envelope: %v", peer, err)
+			}
+			whisperPeer.mark(envelope)
+		}
+	}
+}
+
+// add inserts a new envelope into the message pool to be distributed within the
+// whisper network. It also inserts the envelope into the expiration pool at the
+// appropriate time-stamp.
+func (self *Whisper) add(envelope *Envelope) error {
+	self.poolMu.Lock()
+	defer self.poolMu.Unlock()
+
+	// short circuit when a received envelope has already expired
+	if envelope.Expiry < uint32(time.Now().Unix()) {
+		return nil
+	}
+
+	// Insert the message into the tracked pool
+	hash := envelope.Hash()
+	if _, ok := self.messages[hash]; ok {
+		glog.V(logger.Detail).Infof("whisper envelope already cached: %x\n", envelope)
+		return nil
+	}
+	self.messages[hash] = envelope
+
+	// Insert the message into the expiration pool for later removal
+	if self.expirations[envelope.Expiry] == nil {
+		self.expirations[envelope.Expiry] = set.NewNonTS()
+	}
+	if !self.expirations[envelope.Expiry].Has(hash) {
+		self.expirations[envelope.Expiry].Add(hash)
+
+		// Notify the local node of a message arrival
+		go self.postEvent(envelope)
+	}
+	glog.V(logger.Detail).Infof("cached whisper envelope %x\n", envelope)
+	return nil
+}
+
+// postEvent opens an envelope with the configured identities and delivers the
+// message upstream from application processing.
+func (self *Whisper) postEvent(envelope *Envelope) {
+	if message := self.open(envelope); message != nil {
+		self.filters.Notify(createFilter(message, envelope.Topics), message)
+	}
+}
+
+// open tries to decrypt a whisper envelope with all the configured identities,
+// returning the decrypted message and the key used to achieve it. If not keys
+// are configured, open will return the payload as if non encrypted.
+func (self *Whisper) open(envelope *Envelope) *Message {
+	// Short circuit if no identity is set, and assume clear-text
+	if len(self.keys) == 0 {
+		if message, err := envelope.Open(nil); err == nil {
+			return message
+		}
+	}
+	// Iterate over the keys and try to decrypt the message
+	for _, key := range self.keys {
+		message, err := envelope.Open(key)
+		if err == nil {
+			message.To = &key.PublicKey
+			return message
+		} else if err == ecies.ErrInvalidPublicKey {
+			return message
+		}
+	}
+	// Failed to decrypt, don't return anything
+	return nil
+}
+
+// createFilter creates a message filter to check against installed handlers.
+func createFilter(message *Message, topics []Topic) filter.Filter {
+	matcher := make([][]Topic, len(topics))
+	for i, topic := range topics {
+		matcher[i] = []Topic{topic}
+	}
+	return filterer{
+		to:      string(crypto.FromECDSAPub(message.To)),
+		from:    string(crypto.FromECDSAPub(message.Recover())),
+		matcher: newTopicMatcher(matcher...),
+	}
+}
+
+// update loops until the lifetime of the whisper node, updating its internal
+// state by expiring stale messages from the pool.
+func (self *Whisper) update() {
+	// Start a ticker to check for expirations
+	expire := time.NewTicker(expirationCycle)
+
+	// Repeat updates until termination is requested
+	for {
+		select {
+		case <-expire.C:
+			self.expire()
+
+		case <-self.quit:
+			return
+		}
+	}
+}
+
+// expire iterates over all the expiration timestamps, removing all stale
+// messages from the pools.
+func (self *Whisper) expire() {
+	self.poolMu.Lock()
+	defer self.poolMu.Unlock()
+
+	now := uint32(time.Now().Unix())
+	for then, hashSet := range self.expirations {
+		// Short circuit if a future time
+		if then > now {
+			continue
+		}
+		// Dump all expired messages and remove timestamp
+		hashSet.Each(func(v interface{}) bool {
+			delete(self.messages, v.(common.Hash))
+			return true
+		})
+		self.expirations[then].Clear()
+	}
+}
+
+// envelopes retrieves all the messages currently pooled by the node.
+func (self *Whisper) envelopes() []*Envelope {
+	self.poolMu.RLock()
+	defer self.poolMu.RUnlock()
+
+	envelopes := make([]*Envelope, 0, len(self.messages))
+	for _, envelope := range self.messages {
+		envelopes = append(envelopes, envelope)
+	}
+	return envelopes
+}