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-rw-r--r--whisper/whisperv2/whisper.go378
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diff --git a/whisper/whisperv2/whisper.go b/whisper/whisperv2/whisper.go
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+// 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
+}