whisper: topics replaced by bloom filters

This commit is contained in:
Vlad 2018-03-01 16:04:09 +01:00
parent 5a150e1b77
commit ee75a90ab4
9 changed files with 100 additions and 68 deletions

View File

@ -22,6 +22,7 @@ package main
import (
"bufio"
"crypto/ecdsa"
crand "crypto/rand"
"crypto/sha512"
"encoding/binary"
"encoding/hex"
@ -48,6 +49,7 @@ import (
)
const quitCommand = "~Q"
const entropySize = 32
// singletons
var (
@ -55,6 +57,7 @@ var (
shh *whisper.Whisper
done chan struct{}
mailServer mailserver.WMailServer
entropy [entropySize]byte
input = bufio.NewReader(os.Stdin)
)
@ -274,6 +277,11 @@ func initialize() {
TrustedNodes: peers,
},
}
_, err = crand.Read(entropy[:])
if err != nil {
utils.Fatalf("crypto/rand failed: %s", err)
}
}
func startServer() {
@ -614,10 +622,10 @@ func writeMessageToFile(dir string, msg *whisper.ReceivedMessage) {
}
func requestExpiredMessagesLoop() {
var key, peerID []byte
var key, peerID, bloom []byte
var timeLow, timeUpp uint32
var t string
var xt, empty whisper.TopicType
var xt whisper.TopicType
keyID, err := shh.AddSymKeyFromPassword(msPassword)
if err != nil {
@ -640,18 +648,19 @@ func requestExpiredMessagesLoop() {
utils.Fatalf("Failed to parse the topic: %s", err)
}
xt = whisper.BytesToTopic(x)
bloom = whisper.TopicToBloom(xt)
obfuscateBloom(bloom)
} else {
bloom = whisper.MakeFullNodeBloom()
}
if timeUpp == 0 {
timeUpp = 0xFFFFFFFF
}
data := make([]byte, 8+whisper.TopicLength)
data := make([]byte, 8, 8+whisper.BloomFilterSize)
binary.BigEndian.PutUint32(data, timeLow)
binary.BigEndian.PutUint32(data[4:], timeUpp)
copy(data[8:], xt[:])
if xt == empty {
data = data[:8]
}
data = append(data, bloom...)
var params whisper.MessageParams
params.PoW = *argServerPoW
@ -685,3 +694,20 @@ func extractIDFromEnode(s string) []byte {
}
return n.ID[:]
}
// obfuscateBloom adds 16 random bits to the the bloom
// filter, in order to obfuscate the containing topics.
// it does so deterministically within every session.
// despite additional bits, it will match on average
// 32000 times less messages than full node's bloom filter.
func obfuscateBloom(bloom []byte) {
const half = entropySize / 2
for i := 0; i < half; i++ {
x := int(entropy[i])
if entropy[half+i] < 128 {
x += 256
}
bloom[x/8] = 1 << uint(x%8) // set the bit number X
}
}

View File

@ -107,17 +107,16 @@ func (s *WMailServer) DeliverMail(peer *whisper.Peer, request *whisper.Envelope)
return
}
ok, lower, upper, topic := s.validateRequest(peer.ID(), request)
ok, lower, upper, bloom := s.validateRequest(peer.ID(), request)
if ok {
s.processRequest(peer, lower, upper, topic)
s.processRequest(peer, lower, upper, bloom)
}
}
func (s *WMailServer) processRequest(peer *whisper.Peer, lower, upper uint32, topic whisper.TopicType) []*whisper.Envelope {
func (s *WMailServer) processRequest(peer *whisper.Peer, lower, upper uint32, bloom []byte) []*whisper.Envelope {
ret := make([]*whisper.Envelope, 0)
var err error
var zero common.Hash
var empty whisper.TopicType
kl := NewDbKey(lower, zero)
ku := NewDbKey(upper, zero)
i := s.db.NewIterator(&util.Range{Start: kl.raw, Limit: ku.raw}, nil)
@ -130,7 +129,7 @@ func (s *WMailServer) processRequest(peer *whisper.Peer, lower, upper uint32, to
log.Error(fmt.Sprintf("RLP decoding failed: %s", err))
}
if topic == empty || envelope.Topic == topic {
if whisper.BloomFilterMatch(bloom, envelope.Bloom()) {
if peer == nil {
// used for test purposes
ret = append(ret, &envelope)
@ -152,22 +151,16 @@ func (s *WMailServer) processRequest(peer *whisper.Peer, lower, upper uint32, to
return ret
}
func (s *WMailServer) validateRequest(peerID []byte, request *whisper.Envelope) (bool, uint32, uint32, whisper.TopicType) {
var topic whisper.TopicType
func (s *WMailServer) validateRequest(peerID []byte, request *whisper.Envelope) (bool, uint32, uint32, []byte) {
if s.pow > 0.0 && request.PoW() < s.pow {
return false, 0, 0, topic
return false, 0, 0, nil
}
f := whisper.Filter{KeySym: s.key}
decrypted := request.Open(&f)
if decrypted == nil {
log.Warn(fmt.Sprintf("Failed to decrypt p2p request"))
return false, 0, 0, topic
}
if len(decrypted.Payload) < 8 {
log.Warn(fmt.Sprintf("Undersized p2p request"))
return false, 0, 0, topic
return false, 0, 0, nil
}
src := crypto.FromECDSAPub(decrypted.Src)
@ -179,15 +172,24 @@ func (s *WMailServer) validateRequest(peerID []byte, request *whisper.Envelope)
// if !bytes.Equal(peerID, src) {
if src == nil {
log.Warn(fmt.Sprintf("Wrong signature of p2p request"))
return false, 0, 0, topic
return false, 0, 0, nil
}
var bloom []byte
payloadSize := len(decrypted.Payload)
if payloadSize < 8 {
log.Warn(fmt.Sprintf("Undersized p2p request"))
return false, 0, 0, nil
} else if payloadSize == 8 {
bloom = whisper.MakeFullNodeBloom()
} else if payloadSize < 8+whisper.BloomFilterSize {
log.Warn(fmt.Sprintf("Undersized bloom filter in p2p request"))
return false, 0, 0, nil
} else {
bloom = decrypted.Payload[8 : 8+whisper.BloomFilterSize]
}
lower := binary.BigEndian.Uint32(decrypted.Payload[:4])
upper := binary.BigEndian.Uint32(decrypted.Payload[4:8])
if len(decrypted.Payload) >= 8+whisper.TopicLength {
topic = whisper.BytesToTopic(decrypted.Payload[8:])
}
return true, lower, upper, topic
return true, lower, upper, bloom
}

View File

@ -17,6 +17,7 @@
package mailserver
import (
"bytes"
"crypto/ecdsa"
"encoding/binary"
"io/ioutil"
@ -61,7 +62,7 @@ func generateEnvelope(t *testing.T) *whisper.Envelope {
h := crypto.Keccak256Hash([]byte("test sample data"))
params := &whisper.MessageParams{
KeySym: h[:],
Topic: whisper.TopicType{},
Topic: whisper.TopicType{0x1F, 0x7E, 0xA1, 0x7F},
Payload: []byte("test payload"),
PoW: powRequirement,
WorkTime: 2,
@ -121,6 +122,7 @@ func deliverTest(t *testing.T, server *WMailServer, env *whisper.Envelope) {
upp: birth + 1,
key: testPeerID,
}
singleRequest(t, server, env, p, true)
p.low, p.upp = birth+1, 0xffffffff
@ -131,14 +133,14 @@ func deliverTest(t *testing.T, server *WMailServer, env *whisper.Envelope) {
p.low = birth - 1
p.upp = birth + 1
p.topic[0]++
p.topic[0] = 0xFF
singleRequest(t, server, env, p, false)
}
func singleRequest(t *testing.T, server *WMailServer, env *whisper.Envelope, p *ServerTestParams, expect bool) {
request := createRequest(t, p)
src := crypto.FromECDSAPub(&p.key.PublicKey)
ok, lower, upper, topic := server.validateRequest(src, request)
ok, lower, upper, bloom := server.validateRequest(src, request)
if !ok {
t.Fatalf("request validation failed, seed: %d.", seed)
}
@ -148,12 +150,13 @@ func singleRequest(t *testing.T, server *WMailServer, env *whisper.Envelope, p *
if upper != p.upp {
t.Fatalf("request validation failed (upper bound), seed: %d.", seed)
}
if topic != p.topic {
expectedBloom := whisper.TopicToBloom(p.topic)
if !bytes.Equal(bloom, expectedBloom) {
t.Fatalf("request validation failed (topic), seed: %d.", seed)
}
var exist bool
mail := server.processRequest(nil, p.low, p.upp, p.topic)
mail := server.processRequest(nil, p.low, p.upp, bloom)
for _, msg := range mail {
if msg.Hash() == env.Hash() {
exist = true
@ -166,7 +169,7 @@ func singleRequest(t *testing.T, server *WMailServer, env *whisper.Envelope, p *
}
src[0]++
ok, lower, upper, topic = server.validateRequest(src, request)
ok, lower, upper, bloom = server.validateRequest(src, request)
if !ok {
// request should be valid regardless of signature
t.Fatalf("request validation false negative, seed: %d (lower: %d, upper: %d).", seed, lower, upper)
@ -174,10 +177,11 @@ func singleRequest(t *testing.T, server *WMailServer, env *whisper.Envelope, p *
}
func createRequest(t *testing.T, p *ServerTestParams) *whisper.Envelope {
data := make([]byte, 8+whisper.TopicLength)
bloom := whisper.TopicToBloom(p.topic)
data := make([]byte, 8)
binary.BigEndian.PutUint32(data, p.low)
binary.BigEndian.PutUint32(data[4:], p.upp)
copy(data[8:], p.topic[:])
data = append(data, bloom...)
key, err := shh.GetSymKey(keyID)
if err != nil {

View File

@ -60,7 +60,7 @@ const (
aesKeyLength = 32 // in bytes
aesNonceLength = 12 // in bytes; for more info please see cipher.gcmStandardNonceSize & aesgcm.NonceSize()
keyIDSize = 32 // in bytes
bloomFilterSize = 64 // in bytes
BloomFilterSize = 64 // in bytes
flagsLength = 1
EnvelopeHeaderLength = 20

View File

@ -249,7 +249,7 @@ func (e *Envelope) Bloom() []byte {
// TopicToBloom converts the topic (4 bytes) to the bloom filter (64 bytes)
func TopicToBloom(topic TopicType) []byte {
b := make([]byte, bloomFilterSize)
b := make([]byte, BloomFilterSize)
var index [3]int
for j := 0; j < 3; j++ {
index[j] = int(topic[j])

View File

@ -56,7 +56,7 @@ func newPeer(host *Whisper, remote *p2p.Peer, rw p2p.MsgReadWriter) *Peer {
powRequirement: 0.0,
known: set.New(),
quit: make(chan struct{}),
bloomFilter: makeFullNodeBloom(),
bloomFilter: MakeFullNodeBloom(),
fullNode: true,
}
}
@ -120,7 +120,7 @@ func (peer *Peer) handshake() error {
err = s.Decode(&bloom)
if err == nil {
sz := len(bloom)
if sz != bloomFilterSize && sz != 0 {
if sz != BloomFilterSize && sz != 0 {
return fmt.Errorf("peer [%x] sent bad status message: wrong bloom filter size %d", peer.ID(), sz)
}
peer.setBloomFilter(bloom)
@ -229,7 +229,7 @@ func (peer *Peer) notifyAboutBloomFilterChange(bloom []byte) error {
func (peer *Peer) bloomMatch(env *Envelope) bool {
peer.bloomMu.Lock()
defer peer.bloomMu.Unlock()
return peer.fullNode || bloomFilterMatch(peer.bloomFilter, env.Bloom())
return peer.fullNode || BloomFilterMatch(peer.bloomFilter, env.Bloom())
}
func (peer *Peer) setBloomFilter(bloom []byte) {
@ -238,13 +238,13 @@ func (peer *Peer) setBloomFilter(bloom []byte) {
peer.bloomFilter = bloom
peer.fullNode = isFullNode(bloom)
if peer.fullNode && peer.bloomFilter == nil {
peer.bloomFilter = makeFullNodeBloom()
peer.bloomFilter = MakeFullNodeBloom()
}
}
func makeFullNodeBloom() []byte {
bloom := make([]byte, bloomFilterSize)
for i := 0; i < bloomFilterSize; i++ {
func MakeFullNodeBloom() []byte {
bloom := make([]byte, BloomFilterSize)
for i := 0; i < BloomFilterSize; i++ {
bloom[i] = 0xFF
}
return bloom

View File

@ -152,7 +152,7 @@ func resetParams(t *testing.T) {
}
func initBloom(t *testing.T) {
masterBloomFilter = make([]byte, bloomFilterSize)
masterBloomFilter = make([]byte, BloomFilterSize)
_, err := mrand.Read(masterBloomFilter)
if err != nil {
t.Fatalf("rand failed: %s.", err)
@ -164,7 +164,7 @@ func initBloom(t *testing.T) {
masterBloomFilter[i] = 0xFF
}
if !bloomFilterMatch(masterBloomFilter, msgBloom) {
if !BloomFilterMatch(masterBloomFilter, msgBloom) {
t.Fatalf("bloom mismatch on initBloom.")
}
}
@ -178,7 +178,7 @@ func initialize(t *testing.T) {
for i := 0; i < NumNodes; i++ {
var node TestNode
b := make([]byte, bloomFilterSize)
b := make([]byte, BloomFilterSize)
copy(b, masterBloomFilter)
node.shh = New(&DefaultConfig)
node.shh.SetMinimumPoW(masterPow)

View File

@ -232,11 +232,11 @@ func (whisper *Whisper) SetMaxMessageSize(size uint32) error {
// SetBloomFilter sets the new bloom filter
func (whisper *Whisper) SetBloomFilter(bloom []byte) error {
if len(bloom) != bloomFilterSize {
if len(bloom) != BloomFilterSize {
return fmt.Errorf("invalid bloom filter size: %d", len(bloom))
}
b := make([]byte, bloomFilterSize)
b := make([]byte, BloomFilterSize)
copy(b, bloom)
whisper.settings.Store(bloomFilterIdx, b)
@ -558,14 +558,14 @@ func (whisper *Whisper) Subscribe(f *Filter) (string, error) {
// updateBloomFilter recalculates the new value of bloom filter,
// and informs the peers if necessary.
func (whisper *Whisper) updateBloomFilter(f *Filter) {
aggregate := make([]byte, bloomFilterSize)
aggregate := make([]byte, BloomFilterSize)
for _, t := range f.Topics {
top := BytesToTopic(t)
b := TopicToBloom(top)
aggregate = addBloom(aggregate, b)
}
if !bloomFilterMatch(whisper.BloomFilter(), aggregate) {
if !BloomFilterMatch(whisper.BloomFilter(), aggregate) {
// existing bloom filter must be updated
aggregate = addBloom(whisper.BloomFilter(), aggregate)
whisper.SetBloomFilter(aggregate)
@ -701,7 +701,7 @@ func (whisper *Whisper) runMessageLoop(p *Peer, rw p2p.MsgReadWriter) error {
case bloomFilterExCode:
var bloom []byte
err := packet.Decode(&bloom)
if err == nil && len(bloom) != bloomFilterSize {
if err == nil && len(bloom) != BloomFilterSize {
err = fmt.Errorf("wrong bloom filter size %d", len(bloom))
}
@ -779,11 +779,11 @@ func (whisper *Whisper) add(envelope *Envelope, isP2P bool) (bool, error) {
}
}
if !bloomFilterMatch(whisper.BloomFilter(), envelope.Bloom()) {
if !BloomFilterMatch(whisper.BloomFilter(), envelope.Bloom()) {
// maybe the value was recently changed, and the peers did not adjust yet.
// in this case the previous value is retrieved by BloomFilterTolerance()
// for a short period of peer synchronization.
if !bloomFilterMatch(whisper.BloomFilterTolerance(), envelope.Bloom()) {
if !BloomFilterMatch(whisper.BloomFilterTolerance(), envelope.Bloom()) {
return false, fmt.Errorf("envelope does not match bloom filter, hash=[%v], bloom: \n%x \n%x \n%x",
envelope.Hash().Hex(), whisper.BloomFilter(), envelope.Bloom(), envelope.Topic)
}
@ -1025,12 +1025,12 @@ func isFullNode(bloom []byte) bool {
return true
}
func bloomFilterMatch(filter, sample []byte) bool {
func BloomFilterMatch(filter, sample []byte) bool {
if filter == nil {
return true
}
for i := 0; i < bloomFilterSize; i++ {
for i := 0; i < BloomFilterSize; i++ {
f := filter[i]
s := sample[i]
if (f | s) != f {
@ -1042,8 +1042,8 @@ func bloomFilterMatch(filter, sample []byte) bool {
}
func addBloom(a, b []byte) []byte {
c := make([]byte, bloomFilterSize)
for i := 0; i < bloomFilterSize; i++ {
c := make([]byte, BloomFilterSize)
for i := 0; i < BloomFilterSize; i++ {
c[i] = a[i] | b[i]
}
return c

View File

@ -826,11 +826,11 @@ func TestSymmetricSendKeyMismatch(t *testing.T) {
func TestBloom(t *testing.T) {
topic := TopicType{0, 0, 255, 6}
b := TopicToBloom(topic)
x := make([]byte, bloomFilterSize)
x := make([]byte, BloomFilterSize)
x[0] = byte(1)
x[32] = byte(1)
x[bloomFilterSize-1] = byte(128)
if !bloomFilterMatch(x, b) || !bloomFilterMatch(b, x) {
x[BloomFilterSize-1] = byte(128)
if !BloomFilterMatch(x, b) || !BloomFilterMatch(b, x) {
t.Fatalf("bloom filter does not match the mask")
}
@ -842,11 +842,11 @@ func TestBloom(t *testing.T) {
if err != nil {
t.Fatalf("math rand error")
}
if !bloomFilterMatch(b, b) {
if !BloomFilterMatch(b, b) {
t.Fatalf("bloom filter does not match self")
}
x = addBloom(x, b)
if !bloomFilterMatch(x, b) {
if !BloomFilterMatch(x, b) {
t.Fatalf("bloom filter does not match combined bloom")
}
if !isFullNode(nil) {
@ -856,16 +856,16 @@ func TestBloom(t *testing.T) {
if isFullNode(x) {
t.Fatalf("isFullNode false positive")
}
for i := 0; i < bloomFilterSize; i++ {
for i := 0; i < BloomFilterSize; i++ {
b[i] = byte(255)
}
if !isFullNode(b) {
t.Fatalf("isFullNode false negative")
}
if bloomFilterMatch(x, b) {
if BloomFilterMatch(x, b) {
t.Fatalf("bloomFilterMatch false positive")
}
if !bloomFilterMatch(b, x) {
if !BloomFilterMatch(b, x) {
t.Fatalf("bloomFilterMatch false negative")
}
@ -879,7 +879,7 @@ func TestBloom(t *testing.T) {
t.Fatalf("failed to set bloom filter: %s", err)
}
f = w.BloomFilter()
if !bloomFilterMatch(f, x) || !bloomFilterMatch(x, f) {
if !BloomFilterMatch(f, x) || !BloomFilterMatch(x, f) {
t.Fatalf("retireved wrong bloom filter")
}
}