12 files changed, 837 insertions, 0 deletions
diff --git a/whisper/doc.go b/whisper/doc.go
new file mode 100644
index 000000000..986df8fb9
--- /dev/null
+++ b/whisper/doc.go
@@ -0,0 +1,16 @@
+/*
+Package whisper implements the Whisper PoC-1.
+
+(https://github.com/ethereum/wiki/wiki/Whisper-PoC-1-Protocol-Spec)
+
+Whisper combines aspects of both DHTs and datagram messaging systems (e.g. UDP).
+As such it may be likened and compared to both, not dissimilar to the
+matter/energy duality (apologies to physicists for the blatant abuse of a
+fundamental and beautiful natural principle).
+
+Whisper is a pure identity-based messaging system. Whisper provides a low-level
+(non-application-specific) but easily-accessible API without being based upon
+or prejudiced by the low-level hardware attributes and characteristics,
+particularly the notion of singular endpoints.
+*/
+package whisper
diff --git a/whisper/envelope.go b/whisper/envelope.go
new file mode 100644
index 000000000..20e3e6d39
--- /dev/null
+++ b/whisper/envelope.go
@@ -0,0 +1,129 @@
+package whisper
+
+import (
+	"crypto/ecdsa"
+	"encoding/binary"
+	"fmt"
+	"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/rlp"
+)
+
+const (
+	DefaultPow = 50 * time.Millisecond
+)
+
+type Envelope struct {
+	Expiry uint32 // Whisper protocol specifies int32, really should be int64
+	TTL    uint32 // ^^^^^^
+	Topics [][]byte
+	Data   []byte
+	Nonce  uint32
+
+	hash common.Hash
+}
+
+func (self *Envelope) Hash() common.Hash {
+	if (self.hash == common.Hash{}) {
+		enc, _ := rlp.EncodeToBytes(self)
+		self.hash = crypto.Sha3Hash(enc)
+	}
+	return self.hash
+}
+
+func NewEnvelope(ttl time.Duration, topics [][]byte, data *Message) *Envelope {
+	exp := time.Now().Add(ttl)
+	return &Envelope{
+		Expiry: uint32(exp.Unix()),
+		TTL:    uint32(ttl.Seconds()),
+		Topics: topics,
+		Data:   data.Bytes(),
+		Nonce:  0,
+	}
+}
+
+func (self *Envelope) Seal(pow time.Duration) {
+	self.proveWork(pow)
+}
+
+func (self *Envelope) Open(prv *ecdsa.PrivateKey) (msg *Message, err error) {
+	data := self.Data
+	var message Message
+	dataStart := 1
+	if data[0] > 0 {
+		if len(data) < 66 {
+			return nil, fmt.Errorf("unable to open envelope. First bit set but len(data) < 66")
+		}
+		dataStart = 66
+		message.Flags = data[0]
+		message.Signature = data[1:66]
+	}
+
+	payload := data[dataStart:]
+	if prv != nil {
+		message.Payload, err = crypto.Decrypt(prv, payload)
+		switch err {
+		case nil: // OK
+		case ecies.ErrInvalidPublicKey: // Payload isn't encrypted
+			message.Payload = payload
+			return &message, err
+		default:
+			return nil, fmt.Errorf("unable to open envelope. Decrypt failed: %v", err)
+		}
+	}
+
+	return &message, nil
+}
+
+func (self *Envelope) proveWork(dura time.Duration) {
+	var bestBit int
+	d := make([]byte, 64)
+	enc, _ := rlp.EncodeToBytes(self.withoutNonce())
+	copy(d[:32], enc)
+
+	then := time.Now().Add(dura).UnixNano()
+	for n := uint32(0); time.Now().UnixNano() < then; {
+		for i := 0; i < 1024; i++ {
+			binary.BigEndian.PutUint32(d[60:], n)
+
+			fbs := common.FirstBitSet(common.BigD(crypto.Sha3(d)))
+			if fbs > bestBit {
+				bestBit = fbs
+				self.Nonce = n
+			}
+
+			n++
+		}
+	}
+}
+
+func (self *Envelope) valid() bool {
+	d := make([]byte, 64)
+	enc, _ := rlp.EncodeToBytes(self.withoutNonce())
+	copy(d[:32], enc)
+	binary.BigEndian.PutUint32(d[60:], self.Nonce)
+	return common.FirstBitSet(common.BigD(crypto.Sha3(d))) > 0
+}
+
+func (self *Envelope) withoutNonce() interface{} {
+	return []interface{}{self.Expiry, self.TTL, self.Topics, self.Data}
+}
+
+// rlpenv is an Envelope but is not an rlp.Decoder.
+// It is used for decoding because we need to
+type rlpenv Envelope
+
+func (self *Envelope) DecodeRLP(s *rlp.Stream) error {
+	raw, err := s.Raw()
+	if err != nil {
+		return err
+	}
+	if err := rlp.DecodeBytes(raw, (*rlpenv)(self)); err != nil {
+		return err
+	}
+	self.hash = crypto.Sha3Hash(raw)
+	return nil
+}
diff --git a/whisper/filter.go b/whisper/filter.go
new file mode 100644
index 000000000..b33f2c1a2
--- /dev/null
+++ b/whisper/filter.go
@@ -0,0 +1,10 @@
+package whisper
+
+import "crypto/ecdsa"
+
+type Filter struct {
+	To     *ecdsa.PublicKey
+	From   *ecdsa.PublicKey
+	Topics [][]byte
+	Fn     func(*Message)
+}
diff --git a/whisper/main.go b/whisper/main.go
new file mode 100644
index 000000000..9f35dbb8d
--- /dev/null
+++ b/whisper/main.go
@@ -0,0 +1,37 @@
+// +build none
+
+package main
+
+import (
+	"fmt"
+	"log"
+	"os"
+
+	"github.com/ethereum/go-ethereum/crypto/secp256k1"
+	"github.com/ethereum/go-ethereum/logger"
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/whisper"
+)
+
+func main() {
+	logger.AddLogSystem(logger.NewStdLogSystem(os.Stdout, log.LstdFlags, logger.InfoLevel))
+
+	pub, _ := secp256k1.GenerateKeyPair()
+
+	whisper := whisper.New()
+
+	srv := p2p.Server{
+		MaxPeers:   10,
+		Identity:   p2p.NewSimpleClientIdentity("whisper-go", "1.0", "", string(pub)),
+		ListenAddr: ":30300",
+		NAT:        p2p.UPNP(),
+
+		Protocols: []p2p.Protocol{whisper.Protocol()},
+	}
+	if err := srv.Start(); err != nil {
+		fmt.Println("could not start server:", err)
+		os.Exit(1)
+	}
+
+	select {}
+}
diff --git a/whisper/message.go b/whisper/message.go
new file mode 100644
index 000000000..5d9e5b5c1
--- /dev/null
+++ b/whisper/message.go
@@ -0,0 +1,81 @@
+package whisper
+
+import (
+	"crypto/ecdsa"
+	"time"
+
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+type Message struct {
+	Flags     byte
+	Signature []byte
+	Payload   []byte
+	Sent      int64
+
+	To *ecdsa.PublicKey
+}
+
+func NewMessage(payload []byte) *Message {
+	return &Message{Flags: 0, Payload: payload, Sent: time.Now().Unix()}
+}
+
+func (self *Message) hash() []byte {
+	return crypto.Sha3(append([]byte{self.Flags}, self.Payload...))
+}
+
+func (self *Message) sign(key *ecdsa.PrivateKey) (err error) {
+	self.Flags = 1
+	self.Signature, err = crypto.Sign(self.hash(), key)
+	return
+}
+
+func (self *Message) Recover() *ecdsa.PublicKey {
+	defer func() { recover() }() // in case of invalid sig
+	return crypto.SigToPub(self.hash(), self.Signature)
+}
+
+func (self *Message) Encrypt(to *ecdsa.PublicKey) (err error) {
+	self.Payload, err = crypto.Encrypt(to, self.Payload)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (self *Message) Bytes() []byte {
+	return append([]byte{self.Flags}, append(self.Signature, self.Payload...)...)
+}
+
+type Opts struct {
+	From   *ecdsa.PrivateKey
+	To     *ecdsa.PublicKey
+	Ttl    time.Duration
+	Topics [][]byte
+}
+
+func (self *Message) Seal(pow time.Duration, opts Opts) (*Envelope, error) {
+	if opts.From != nil {
+		err := self.sign(opts.From)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if opts.To != nil {
+		err := self.Encrypt(opts.To)
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	if opts.Ttl == 0 {
+		opts.Ttl = DefaultTtl
+	}
+
+	envelope := NewEnvelope(opts.Ttl, opts.Topics, self)
+	envelope.Seal(pow)
+
+	return envelope, nil
+}
diff --git a/whisper/messages_test.go b/whisper/messages_test.go
new file mode 100644
index 000000000..93caa31b3
--- /dev/null
+++ b/whisper/messages_test.go
@@ -0,0 +1,50 @@
+package whisper
+
+import (
+	"bytes"
+	"crypto/elliptic"
+	"fmt"
+	"testing"
+
+	"github.com/ethereum/go-ethereum/crypto"
+)
+
+func TestSign(t *testing.T) {
+	prv, _ := crypto.GenerateKey()
+	msg := NewMessage([]byte("hello world"))
+	msg.sign(prv)
+
+	pubKey := msg.Recover()
+	p1 := elliptic.Marshal(crypto.S256(), prv.PublicKey.X, prv.PublicKey.Y)
+	p2 := elliptic.Marshal(crypto.S256(), pubKey.X, pubKey.Y)
+
+	if !bytes.Equal(p1, p2) {
+		t.Error("recovered pub key did not match")
+	}
+}
+
+func TestMessageEncryptDecrypt(t *testing.T) {
+	prv1, _ := crypto.GenerateKey()
+	prv2, _ := crypto.GenerateKey()
+
+	data := []byte("hello world")
+	msg := NewMessage(data)
+	envelope, err := msg.Seal(DefaultPow, Opts{
+		From: prv1,
+		To:   &prv2.PublicKey,
+	})
+	if err != nil {
+		fmt.Println(err)
+		t.FailNow()
+	}
+
+	msg1, err := envelope.Open(prv2)
+	if err != nil {
+		t.Error(err)
+		t.FailNow()
+	}
+
+	if !bytes.Equal(msg1.Payload, data) {
+		t.Error("encryption error. data did not match")
+	}
+}
diff --git a/whisper/peer.go b/whisper/peer.go
new file mode 100644
index 000000000..338166c25
--- /dev/null
+++ b/whisper/peer.go
@@ -0,0 +1,113 @@
+package whisper
+
+import (
+	"fmt"
+	"time"
+
+	"github.com/ethereum/go-ethereum/p2p"
+	"github.com/ethereum/go-ethereum/rlp"
+	"gopkg.in/fatih/set.v0"
+)
+
+const (
+	protocolVersion uint64 = 0x02
+)
+
+type peer struct {
+	host *Whisper
+	peer *p2p.Peer
+	ws   p2p.MsgReadWriter
+
+	// XXX Eventually this is going to reach exceptional large space. We need an expiry here
+	known *set.Set
+
+	quit chan struct{}
+}
+
+func NewPeer(host *Whisper, p *p2p.Peer, ws p2p.MsgReadWriter) *peer {
+	return &peer{host, p, ws, set.New(), make(chan struct{})}
+}
+
+func (self *peer) init() error {
+	if err := self.handleStatus(); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (self *peer) start() {
+	go self.update()
+	self.peer.Debugln("whisper started")
+}
+
+func (self *peer) stop() {
+	self.peer.Debugln("whisper stopped")
+
+	close(self.quit)
+}
+
+func (self *peer) update() {
+	relay := time.NewTicker(300 * time.Millisecond)
+out:
+	for {
+		select {
+		case <-relay.C:
+			err := self.broadcast(self.host.envelopes())
+			if err != nil {
+				self.peer.Infoln("broadcast err:", err)
+				break out
+			}
+
+		case <-self.quit:
+			break out
+		}
+	}
+}
+
+func (self *peer) broadcast(envelopes []*Envelope) error {
+	envs := make([]*Envelope, 0, len(envelopes))
+	for _, env := range envelopes {
+		if !self.known.Has(env.Hash()) {
+			envs = append(envs, env)
+			self.known.Add(env.Hash())
+		}
+	}
+	if len(envs) > 0 {
+		if err := p2p.Send(self.ws, envelopesMsg, envs); err != nil {
+			return err
+		}
+		self.peer.DebugDetailln("broadcasted", len(envs), "message(s)")
+	}
+	return nil
+}
+
+func (self *peer) addKnown(envelope *Envelope) {
+	self.known.Add(envelope.Hash())
+}
+
+func (self *peer) handleStatus() error {
+	ws := self.ws
+	if err := p2p.SendItems(ws, statusMsg, protocolVersion); err != nil {
+		return err
+	}
+	msg, err := ws.ReadMsg()
+	if err != nil {
+		return err
+	}
+	if msg.Code != statusMsg {
+		return fmt.Errorf("peer send %x before status msg", msg.Code)
+	}
+	s := rlp.NewStream(msg.Payload)
+	if _, err := s.List(); err != nil {
+		return fmt.Errorf("bad status message: %v", err)
+	}
+	pv, err := s.Uint()
+	if err != nil {
+		return fmt.Errorf("bad status message: %v", err)
+	}
+	if pv != protocolVersion {
+		return fmt.Errorf("protocol version mismatch %d != %d", pv, protocolVersion)
+	}
+	return msg.Discard() // ignore anything after protocol version
+}
diff --git a/whisper/sort.go b/whisper/sort.go
new file mode 100644
index 000000000..313ba5ac0
--- /dev/null
+++ b/whisper/sort.go
@@ -0,0 +1,29 @@
+package whisper
+
+import (
+	"sort"
+
+	"github.com/ethereum/go-ethereum/common"
+)
+
+type sortedKeys struct {
+	k []int32
+}
+
+func (self *sortedKeys) Len() int           { return len(self.k) }
+func (self *sortedKeys) Less(i, j int) bool { return self.k[i] < self.k[j] }
+func (self *sortedKeys) Swap(i, j int)      { self.k[i], self.k[j] = self.k[j], self.k[i] }
+
+func sortKeys(m map[int32]common.Hash) []int32 {
+	sorted := new(sortedKeys)
+	sorted.k = make([]int32, len(m))
+	i := 0
+	for key, _ := range m {
+		sorted.k[i] = key
+		i++
+	}
+
+	sort.Sort(sorted)
+
+	return sorted.k
+}
diff --git a/whisper/sort_test.go b/whisper/sort_test.go
new file mode 100644
index 000000000..a61fde4c2
--- /dev/null
+++ b/whisper/sort_test.go
@@ -0,0 +1,23 @@
+package whisper
+
+import (
+	"testing"
+
+	"github.com/ethereum/go-ethereum/common"
+)
+
+func TestSorting(t *testing.T) {
+	m := map[int32]common.Hash{
+		1: {1},
+		3: {3},
+		2: {2},
+		5: {5},
+	}
+	exp := []int32{1, 2, 3, 5}
+	res := sortKeys(m)
+	for i, k := range res {
+		if k != exp[i] {
+			t.Error(k, "failed. Expected", exp[i])
+		}
+	}
+}
diff --git a/whisper/util.go b/whisper/util.go
new file mode 100644
index 000000000..7a222395f
--- /dev/null
+++ b/whisper/util.go
@@ -0,0 +1,36 @@
+package whisper
+
+import "github.com/ethereum/go-ethereum/crypto"
+
+func hashTopic(topic []byte) []byte {
+	return crypto.Sha3(topic)[:4]
+}
+
+// NOTE this isn't DRY, but I don't want to iterate twice.
+
+// Returns a formatted topics byte slice.
+// data: unformatted data (e.g., no hashes needed)
+func Topics(data [][]byte) [][]byte {
+	d := make([][]byte, len(data))
+	for i, byts := range data {
+		d[i] = hashTopic(byts)
+	}
+	return d
+}
+
+func TopicsFromString(data ...string) [][]byte {
+	d := make([][]byte, len(data))
+	for i, str := range data {
+		d[i] = hashTopic([]byte(str))
+	}
+	return d
+}
+
+func bytesToMap(s [][]byte) map[string]struct{} {
+	m := make(map[string]struct{})
+	for _, topic := range s {
+		m[string(topic)] = struct{}{}
+	}
+
+	return m
+}
diff --git a/whisper/whisper.go b/whisper/whisper.go
new file mode 100644
index 000000000..1d019aea5
--- /dev/null
+++ b/whisper/whisper.go
@@ -0,0 +1,275 @@
+package whisper
+
+import (
+	"crypto/ecdsa"
+	"errors"
+	"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/p2p"
+	"gopkg.in/fatih/set.v0"
+)
+
+const (
+	statusMsg      = 0x0
+	envelopesMsg   = 0x01
+	whisperVersion = 0x02
+)
+
+type MessageEvent struct {
+	To      *ecdsa.PrivateKey
+	From    *ecdsa.PublicKey
+	Message *Message
+}
+
+const DefaultTtl = 50 * time.Second
+
+var wlogger = logger.NewLogger("SHH")
+
+type Whisper struct {
+	protocol p2p.Protocol
+	filters  *filter.Filters
+
+	mmu      sync.RWMutex
+	messages map[common.Hash]*Envelope
+	expiry   map[uint32]*set.SetNonTS
+
+	quit chan struct{}
+
+	keys map[string]*ecdsa.PrivateKey
+}
+
+func New() *Whisper {
+	whisper := &Whisper{
+		messages: make(map[common.Hash]*Envelope),
+		filters:  filter.New(),
+		expiry:   make(map[uint32]*set.SetNonTS),
+		quit:     make(chan struct{}),
+		keys:     make(map[string]*ecdsa.PrivateKey),
+	}
+	whisper.filters.Start()
+
+	// p2p whisper sub protocol handler
+	whisper.protocol = p2p.Protocol{
+		Name:    "shh",
+		Version: uint(whisperVersion),
+		Length:  2,
+		Run:     whisper.msgHandler,
+	}
+
+	return whisper
+}
+
+func (self *Whisper) Version() uint {
+	return self.protocol.Version
+}
+
+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[string(crypto.FromECDSAPub(&key.PublicKey))] = key
+
+	return key
+}
+
+func (self *Whisper) HasIdentity(key *ecdsa.PublicKey) bool {
+	return self.keys[string(crypto.FromECDSAPub(key))] != nil
+}
+
+func (self *Whisper) GetIdentity(key *ecdsa.PublicKey) *ecdsa.PrivateKey {
+	return self.keys[string(crypto.FromECDSAPub(key))]
+}
+
+// func (self *Whisper) RemoveIdentity(key *ecdsa.PublicKey) bool {
+// 	k := string(crypto.FromECDSAPub(key))
+// 	if _, ok := self.keys[k]; ok {
+// 		delete(self.keys, k)
+// 		return true
+// 	}
+// 	return false
+// }
+
+func (self *Whisper) Watch(opts Filter) int {
+	return self.filters.Install(filter.Generic{
+		Str1: string(crypto.FromECDSAPub(opts.To)),
+		Str2: string(crypto.FromECDSAPub(opts.From)),
+		Data: bytesToMap(opts.Topics),
+		Fn: func(data interface{}) {
+			opts.Fn(data.(*Message))
+		},
+	})
+}
+
+func (self *Whisper) Unwatch(id int) {
+	self.filters.Uninstall(id)
+}
+
+func (self *Whisper) Messages(id int) (messages []*Message) {
+	filter := self.filters.Get(id)
+	if filter != nil {
+		for _, e := range self.messages {
+			if msg, key := self.open(e); msg != nil {
+				f := createFilter(msg, e.Topics, key)
+				if self.filters.Match(filter, f) {
+					messages = append(messages, msg)
+				}
+			}
+		}
+	}
+
+	return
+}
+
+// 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
+		}
+
+		var envelopes []*Envelope
+		if err := msg.Decode(&envelopes); err != nil {
+			peer.Infoln(err)
+			continue
+		}
+
+		for _, envelope := range envelopes {
+			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)
+	}
+
+	wlogger.DebugDetailf("added whisper envelope %x\n", 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.(common.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) {
+	if message, key := self.open(envelope); message != nil {
+		self.filters.Notify(createFilter(message, envelope.Topics, key), message)
+	}
+}
+
+func (self *Whisper) open(envelope *Envelope) (*Message, *ecdsa.PrivateKey) {
+	for _, key := range self.keys {
+		if message, err := envelope.Open(key); err == nil || (err != nil && err == ecies.ErrInvalidPublicKey) {
+			message.To = &key.PublicKey
+
+			return message, key
+		}
+	}
+
+	return nil, nil
+}
+
+func (self *Whisper) Protocol() p2p.Protocol {
+	return self.protocol
+}
+
+func createFilter(message *Message, topics [][]byte, key *ecdsa.PrivateKey) filter.Filter {
+	return filter.Generic{
+		Str1: string(crypto.FromECDSAPub(&key.PublicKey)), Str2: string(crypto.FromECDSAPub(message.Recover())),
+		Data: bytesToMap(topics),
+	}
+}
diff --git a/whisper/whisper_test.go b/whisper/whisper_test.go
new file mode 100644
index 000000000..3e3945a0a
--- /dev/null
+++ b/whisper/whisper_test.go
@@ -0,0 +1,38 @@
+package whisper
+
+import (
+	"fmt"
+	"testing"
+	"time"
+)
+
+func TestEvent(t *testing.T) {
+	res := make(chan *Message, 1)
+	whisper := New()
+	id := whisper.NewIdentity()
+	whisper.Watch(Filter{
+		To: &id.PublicKey,
+		Fn: func(msg *Message) {
+			res <- msg
+		},
+	})
+
+	msg := NewMessage([]byte(fmt.Sprintf("Hello world. This is whisper-go. Incase you're wondering; the time is %v", time.Now())))
+	envelope, err := msg.Seal(DefaultPow, Opts{
+		Ttl:  DefaultTtl,
+		From: id,
+		To:   &id.PublicKey,
+	})
+	if err != nil {
+		fmt.Println(err)
+		t.FailNow()
+	}
+
+	tick := time.NewTicker(time.Second)
+	whisper.postEvent(envelope)
+	select {
+	case <-res:
+	case <-tick.C:
+		t.Error("did not receive message")
+	}
+}