Official Go implementation of the Ethereum protocol
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go-ethereum/whisper/whisper.go

246 lines
4.8 KiB

package whisper
import (
"bytes"
"crypto/ecdsa"
"errors"
"sync"
"time"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/event/filter"
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"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/p2p"
"github.com/obscuren/ecies"
"gopkg.in/fatih/set.v0"
)
// MOVE ME
type Hash struct {
hash string
}
var EmptyHash Hash
func H(hash []byte) Hash {
return Hash{string(hash)}
}
func HS(hash string) Hash {
return Hash{hash}
}
func (self Hash) Compare(other Hash) int {
return bytes.Compare([]byte(self.hash), []byte(other.hash))
}
// MOVE ME END
const (
statusMsg = 0x0
envelopesMsg = 0x01
)
type MessageEvent struct {
To *ecdsa.PrivateKey
From *ecdsa.PublicKey
Message *Message
}
const DefaultTtl = 50 * time.Second
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var wlogger = logger.NewLogger("SHH")
type Whisper struct {
protocol p2p.Protocol
filters *filter.Filters
mmu sync.RWMutex
messages map[Hash]*Envelope
expiry map[uint32]*set.SetNonTS
quit chan struct{}
keys []*ecdsa.PrivateKey
}
func New() *Whisper {
whisper := &Whisper{
messages: make(map[Hash]*Envelope),
filters: filter.New(),
expiry: make(map[uint32]*set.SetNonTS),
quit: make(chan struct{}),
}
whisper.filters.Start()
// p2p whisper sub protocol handler
whisper.protocol = p2p.Protocol{
Name: "shh",
Version: 2,
Length: 2,
Run: whisper.msgHandler,
}
return whisper
}
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func (self *Whisper) Start() {
wlogger.Infoln("Whisper started")
go self.update()
}
func (self *Whisper) Stop() {
close(self.quit)
}
func (self *Whisper) Send(envelope *Envelope) error {
return self.add(envelope)
}
func (self *Whisper) NewIdentity() *ecdsa.PrivateKey {
key, err := crypto.GenerateKey()
if err != nil {
panic(err)
}
self.keys = append(self.keys, key)
return key
}
func (self *Whisper) HasIdentity(key *ecdsa.PrivateKey) bool {
for _, key := range self.keys {
if key.D.Cmp(key.D) == 0 {
return true
}
}
return false
}
func (self *Whisper) Watch(opts Filter) int {
return self.filters.Install(filter.Generic{
Str1: string(crypto.FromECDSA(opts.To)),
Str2: string(crypto.FromECDSAPub(opts.From)),
Data: bytesToMap(opts.Topics),
Fn: func(data interface{}) {
opts.Fn(data.(*Message))
},
})
}
// Main handler for passing whisper messages to whisper peer objects
func (self *Whisper) msgHandler(peer *p2p.Peer, ws p2p.MsgReadWriter) error {
wpeer := NewPeer(self, peer, ws)
// initialise whisper peer (handshake/status)
if err := wpeer.init(); err != nil {
return err
}
// kick of the main handler for broadcasting/managing envelopes
go wpeer.start()
defer wpeer.stop()
// Main *read* loop. Writing is done by the peer it self.
for {
msg, err := ws.ReadMsg()
if err != nil {
return err
}
envelope, err := NewEnvelopeFromReader(msg.Payload)
if err != nil {
peer.Infoln(err)
continue
}
if err := self.add(envelope); err != nil {
// TODO Punish peer here. Invalid envelope.
peer.Infoln(err)
}
wpeer.addKnown(envelope)
}
}
// takes care of adding envelopes to the messages pool. At this moment no sanity checks are being performed.
func (self *Whisper) add(envelope *Envelope) error {
if !envelope.valid() {
return errors.New("invalid pow provided for envelope")
}
self.mmu.Lock()
defer self.mmu.Unlock()
hash := envelope.Hash()
self.messages[hash] = envelope
if self.expiry[envelope.Expiry] == nil {
self.expiry[envelope.Expiry] = set.NewNonTS()
}
if !self.expiry[envelope.Expiry].Has(hash) {
self.expiry[envelope.Expiry].Add(hash)
go self.postEvent(envelope)
}
return nil
}
func (self *Whisper) update() {
expire := time.NewTicker(800 * time.Millisecond)
out:
for {
select {
case <-expire.C:
self.expire()
case <-self.quit:
break out
}
}
}
func (self *Whisper) expire() {
self.mmu.Lock()
defer self.mmu.Unlock()
now := uint32(time.Now().Unix())
for then, hashSet := range self.expiry {
if then > now {
continue
}
hashSet.Each(func(v interface{}) bool {
delete(self.messages, v.(Hash))
return true
})
self.expiry[then].Clear()
}
}
func (self *Whisper) envelopes() (envelopes []*Envelope) {
self.mmu.RLock()
defer self.mmu.RUnlock()
envelopes = make([]*Envelope, len(self.messages))
i := 0
for _, envelope := range self.messages {
envelopes[i] = envelope
i++
}
return
}
func (self *Whisper) postEvent(envelope *Envelope) {
for _, key := range self.keys {
if message, err := envelope.Open(key); err == nil || (err != nil && err == ecies.ErrInvalidPublicKey) {
// Create a custom filter?
self.filters.Notify(filter.Generic{
Str1: string(crypto.FromECDSA(key)), Str2: string(crypto.FromECDSAPub(message.Recover())),
Data: bytesToMap(envelope.Topics),
}, message)
} else {
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wlogger.Infoln(err)
}
}
}
func (self *Whisper) Protocol() p2p.Protocol {
return self.protocol
}