Create temporary whisperv6 patch file. Closes #636

Gopkg.lock

@@ -109,7 +109,7 @@
     "whisper/notifications",
     "whisper/whisperv5"
   ]
-  revision = "6bba5c70ba424f5efb448536ae3d000f96e7cc9e"
+  revision = "09f08d50335df2d8c9b9f062b18f0ebd3a84133d"
   source = "https://github.com/status-im/go-ethereum.git"
 
 [[projects]]

_assets/patches/geth/0012-disable-filter-timeout.patch

@@ -14,3 +14,19 @@ index e3c2f4a97..96d895fdc 100644
  )
  
  var (
+diff --git a/whisper/whisperv6/api.go b/whisper/whisperv6/api.go
+index a2c75a41c..4d3662880 100644
+--- a/whisper/whisperv6/api.go
++++ b/whisper/whisperv6/api.go
+@@ -33,7 +33,10 @@ import (
+ )
+ 
+ const (
+-	filterTimeout = 300 // filters are considered timeout out after filterTimeout seconds
++	// HACK: make the filter essentially never timeout (1 year of timeout time)
++	// It's a hack, but that simplifies rebasing process, because the patch consists
++	// only of 1 LoC change (excluding this comment).
++	filterTimeout = 525600 * 60 // filters are considered timeout out after filterTimeout seconds
+ )
+ 
+ // List of errors

_assets/patches/geth/README.md

@@ -24,7 +24,9 @@ Instructions for creating a patch from the command line:
 - [`0004-whisper-notifications.patch`](./0004-whisper-notifications.patch) — adds Whisper notifications (need to be reviewed and documented)
 - [`0006-latest-cht.patch`](./0006-latest-cht.patch) – updates CHT root hashes, should be updated regularly to keep sync fast, until proper Trusted Checkpoint sync is not implemented as part of LES/2 protocol.
 - [`0007-README.patch`](./0007-README.patch) — update upstream README.md.
+- [`0009-whisper-envelopes-tracing.patch`](./0009-whisper-envelopes-tracing.patch) — adds Whisper envelope tracing (need to be reviewed and documented)
 - [`0010-geth-17-fix-npe-in-filter-system.patch`](./0010-geth-17-fix-npe-in-filter-system.patch) - Temp patch for 1.7.x to fix a NPE in the filter system.
+- [`0011-geth-17-whisperv6-70fbc87.patch`](./0011-geth-17-whisperv6-70fbc87.patch) - Temp patch for 1.7.x to update whisper v6 to the upstream version at the `70fbc87` SHA1.
 
 # Updating upstream version
 
@@ -37,18 +39,21 @@ When a new stable release of `go-ethereum` comes out, we need to upgrade our for
 #### I. In our fork at /status-im/go-ethereum.
 
 1. Remove the local `develop` branch.
+
     ```bash
     git branch -D develop
     ```
 
-2. Pull upstream release branch into `develop` branch.
+1. Pull upstream release branch into `develop` branch.
+
     ```bash
     git pull git@github.com:ethereum/go-ethereum.git <release_branch>:develop
     ```
     In our case `<release_branch>` would be `release/1.7` because the current stable version is
     1.7.x.
 
-3. Apply patches
+1. Apply patches
+
     ```bash
     for patch in $GOPATH/src/github.com/status-im/status-go/_assets/patches/geth/*.patch;
     do
@@ -61,7 +66,8 @@ Once patches applied, you might want to inspect changes between current vendored
     diff -Nru -x "*_test.go" -x "vendor" -x ".git" -x "tests" -x "build" --brief $GOPATH/src/github.com/status-im/go-ethereum $GOPATH/src/github.com/status-im/status-go/vendor/github.com/ethereum/go-ethereum
     ```
 
-4. Push `develop` branch to our remote, rewriting history
+1. Push `develop` branch to our remote, rewriting history
+
     ```bash
     git push -f origin develop
     ```
@@ -69,15 +75,17 @@ git push -f origin develop
 #### II. In status-go repository
 
 1. Update vendored `go-ethereum` (note that we use upstream's address there, we override the download link to our fork address in `Gopkg.toml`)
+
     ```bash
     dep ensure --update github.com/ethereum/go-ethereum
     ```
 
     `Gopkg.lock` will change and files within `vendor/ethereum/go-ethereum`.
 
-2. Run tests
+1. Run tests
+
     ```bash
     make ci
     ```
 
-3. Commit & push changes, create a PR
+1. Commit & push changes, create a PR

vendor/github.com/ethereum/go-ethereum/whisper/whisperv6/api.go

@@ -33,9 +33,13 @@ import (
 )
 
 const (
-	filterTimeout = 300 // filters are considered timeout out after filterTimeout seconds
+	// HACK: make the filter essentially never timeout (1 year of timeout time)
+	// It's a hack, but that simplifies rebasing process, because the patch consists
+	// only of 1 LoC change (excluding this comment).
+	filterTimeout = 525600 * 60 // filters are considered timeout out after filterTimeout seconds
 )
 
+// List of errors
 var (
 	ErrSymAsym              = errors.New("specify either a symmetric or an asymmetric key")
 	ErrInvalidSymmetricKey  = errors.New("invalid symmetric key")
@@ -116,12 +120,17 @@ func (api *PublicWhisperAPI) SetMaxMessageSize(ctx context.Context, size uint32)
 	return true, api.w.SetMaxMessageSize(size)
 }
 
-// SetMinPow sets the minimum PoW for a message before it is accepted.
+// SetMinPoW sets the minimum PoW, and notifies the peers.
 func (api *PublicWhisperAPI) SetMinPoW(ctx context.Context, pow float64) (bool, error) {
 	return true, api.w.SetMinimumPoW(pow)
 }
 
-// MarkTrustedPeer marks a peer trusted. , which will allow it to send historic (expired) messages.
+// SetBloomFilter sets the new value of bloom filter, and notifies the peers.
+func (api *PublicWhisperAPI) SetBloomFilter(ctx context.Context, bloom hexutil.Bytes) (bool, error) {
+	return true, api.w.SetBloomFilter(bloom)
+}
+
+// MarkTrustedPeer marks a peer trusted, which will allow it to send historic (expired) messages.
 // Note: This function is not adding new nodes, the node needs to exists as a peer.
 func (api *PublicWhisperAPI) MarkTrustedPeer(ctx context.Context, enode string) (bool, error) {
 	n, err := discover.ParseNode(enode)
@@ -169,7 +178,7 @@ func (api *PublicWhisperAPI) GetPublicKey(ctx context.Context, id string) (hexut
 	return crypto.FromECDSAPub(&key.PublicKey), nil
 }
 
-// GetPublicKey returns the private key associated with the given key. The key is the hex
+// GetPrivateKey returns the private key associated with the given key. The key is the hex
 // encoded representation of a key in the form specified in section 4.3.6 of ANSI X9.62.
 func (api *PublicWhisperAPI) GetPrivateKey(ctx context.Context, id string) (hexutil.Bytes, error) {
 	key, err := api.w.GetPrivateKey(id)
@@ -272,7 +281,7 @@ func (api *PublicWhisperAPI) Post(ctx context.Context, req NewMessage) (bool, er
 		if params.KeySym, err = api.w.GetSymKey(req.SymKeyID); err != nil {
 			return false, err
 		}
-		if !validateSymmetricKey(params.KeySym) {
+		if !validateDataIntegrity(params.KeySym, aesKeyLength) {
 			return false, ErrInvalidSymmetricKey
 		}
 	}
@@ -378,7 +387,7 @@ func (api *PublicWhisperAPI) Messages(ctx context.Context, crit Criteria) (*rpc.
 		if err != nil {
 			return nil, err
 		}
-		if !validateSymmetricKey(key) {
+		if !validateDataIntegrity(key, aesKeyLength) {
 			return nil, ErrInvalidSymmetricKey
 		}
 		filter.KeySym = key
@@ -550,7 +559,7 @@ func (api *PublicWhisperAPI) NewMessageFilter(req Criteria) (string, error) {
 		if keySym, err = api.w.GetSymKey(req.SymKeyID); err != nil {
 			return "", err
 		}
-		if !validateSymmetricKey(keySym) {
+		if !validateDataIntegrity(keySym, aesKeyLength) {
 			return "", ErrInvalidSymmetricKey
 		}
 	}
@@ -562,7 +571,7 @@ func (api *PublicWhisperAPI) NewMessageFilter(req Criteria) (string, error) {
 	}
 
 	if len(req.Topics) > 0 {
-		topics = make([][]byte, 1)
+		topics = make([][]byte, 0, len(req.Topics))
 		for _, topic := range req.Topics {
 			topics = append(topics, topic[:])
 		}

vendor/github.com/ethereum/go-ethereum/whisper/whisperv6/config.go

@@ -16,11 +16,13 @@
 
 package whisperv6
 
+// Config represents the configuration state of a whisper node.
 type Config struct {
 	MaxMessageSize     uint32  `toml:",omitempty"`
 	MinimumAcceptedPOW float64 `toml:",omitempty"`
 }
 
+// DefaultConfig represents (shocker!) the default configuration.
 var DefaultConfig = Config{
 	MaxMessageSize:     DefaultMaxMessageSize,
 	MinimumAcceptedPOW: DefaultMinimumPoW,

vendor/github.com/ethereum/go-ethereum/whisper/whisperv6/doc.go

@@ -27,6 +27,9 @@ Whisper is a pure identity-based messaging system. Whisper provides a low-level
 or prejudiced by the low-level hardware attributes and characteristics,
 particularly the notion of singular endpoints.
 */
+
+// Contains the Whisper protocol constant definitions
+
 package whisperv6
 
 import (
@@ -34,39 +37,46 @@ import (
 	"time"
 )
 
+// Whisper protocol parameters
 const (
-	EnvelopeVersion    = uint64(0)
-	ProtocolVersion    = uint64(5)
-	ProtocolVersionStr = "5.0"
-	ProtocolName       = "shh"
+	ProtocolVersion    = uint64(6) // Protocol version number
+	ProtocolVersionStr = "6.0"     // The same, as a string
+	ProtocolName       = "shh"     // Nickname of the protocol in geth
 
+	// whisper protocol message codes, according to EIP-627
 	statusCode           = 0   // used by whisper protocol
 	messagesCode         = 1   // normal whisper message
-	p2pCode              = 2 // peer-to-peer message (to be consumed by the peer, but not forwarded any further)
-	p2pRequestCode       = 3 // peer-to-peer message, used by Dapp protocol
-	NumberOfMessageCodes = 64
+	powRequirementCode   = 2   // PoW requirement
+	bloomFilterExCode    = 3   // bloom filter exchange
+	p2pRequestCode       = 126 // peer-to-peer message, used by Dapp protocol
+	p2pMessageCode       = 127 // peer-to-peer message (to be consumed by the peer, but not forwarded any further)
+	NumberOfMessageCodes = 128
 
-	paddingMask   = byte(3)
+	SizeMask      = byte(3) // mask used to extract the size of payload size field from the flags
 	signatureFlag = byte(4)
 
-	TopicLength     = 4
-	signatureLength = 65
-	aesKeyLength    = 32
-	AESNonceLength  = 12
-	keyIdSize       = 32
+	TopicLength     = 4  // in bytes
+	signatureLength = 65 // in bytes
+	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
+	flagsLength     = 1
+
+	EnvelopeHeaderLength = 20
 
 	MaxMessageSize        = uint32(10 * 1024 * 1024) // maximum accepted size of a message.
 	DefaultMaxMessageSize = uint32(1024 * 1024)
 	DefaultMinimumPoW     = 0.2
 
-	padSizeLimit      = 256 // just an arbitrary number, could be changed without breaking the protocol (must not exceed 2^24)
+	padSizeLimit      = 256 // just an arbitrary number, could be changed without breaking the protocol
 	messageQueueLimit = 1024
 
 	expirationCycle   = time.Second
 	transmissionCycle = 300 * time.Millisecond
 
 	DefaultTTL           = 50 // seconds
-	SynchAllowance = 10 // seconds
+	DefaultSyncAllowance = 10 // seconds
 )
 
 type unknownVersionError uint64

vendor/github.com/ethereum/go-ethereum/whisper/whisperv6/envelope.go

@@ -36,76 +36,60 @@ import (
 // Envelope represents a clear-text data packet to transmit through the Whisper
 // network. Its contents may or may not be encrypted and signed.
 type Envelope struct {
-	Version  []byte
 	Expiry uint32
 	TTL    uint32
 	Topic  TopicType
-	AESNonce []byte
 	Data   []byte
-	EnvNonce uint64
+	Nonce  uint64
 
 	pow float64 // Message-specific PoW as described in the Whisper specification.
+
+	// the following variables should not be accessed directly, use the corresponding function instead: Hash(), Bloom()
 	hash  common.Hash // Cached hash of the envelope to avoid rehashing every time.
-	// Don't access hash directly, use Hash() function instead.
+	bloom []byte
 }
 
 // size returns the size of envelope as it is sent (i.e. public fields only)
 func (e *Envelope) size() int {
-	return 20 + len(e.Version) + len(e.AESNonce) + len(e.Data)
+	return EnvelopeHeaderLength + len(e.Data)
 }
 
 // rlpWithoutNonce returns the RLP encoded envelope contents, except the nonce.
 func (e *Envelope) rlpWithoutNonce() []byte {
-	res, _ := rlp.EncodeToBytes([]interface{}{e.Version, e.Expiry, e.TTL, e.Topic, e.AESNonce, e.Data})
+	res, _ := rlp.EncodeToBytes([]interface{}{e.Expiry, e.TTL, e.Topic, e.Data})
 	return res
 }
 
 // NewEnvelope wraps a Whisper message with expiration and destination data
 // included into an envelope for network forwarding.
-func NewEnvelope(ttl uint32, topic TopicType, aesNonce []byte, msg *sentMessage) *Envelope {
+func NewEnvelope(ttl uint32, topic TopicType, msg *sentMessage) *Envelope {
 	env := Envelope{
-		Version:  make([]byte, 1),
 		Expiry: uint32(time.Now().Add(time.Second * time.Duration(ttl)).Unix()),
 		TTL:    ttl,
 		Topic:  topic,
-		AESNonce: aesNonce,
 		Data:   msg.Raw,
-		EnvNonce: 0,
-	}
-
-	if EnvelopeVersion < 256 {
-		env.Version[0] = byte(EnvelopeVersion)
-	} else {
-		panic("please increase the size of Envelope.Version before releasing this version")
+		Nonce:  0,
 	}
 
 	return &env
 }
 
-func (e *Envelope) IsSymmetric() bool {
-	return len(e.AESNonce) > 0
-}
-
-func (e *Envelope) isAsymmetric() bool {
-	return !e.IsSymmetric()
-}
-
-func (e *Envelope) Ver() uint64 {
-	return bytesToUintLittleEndian(e.Version)
-}
-
 // Seal closes the envelope by spending the requested amount of time as a proof
 // of work on hashing the data.
 func (e *Envelope) Seal(options *MessageParams) error {
-	var target, bestBit int
 	if options.PoW == 0 {
-		// adjust for the duration of Seal() execution only if execution time is predefined unconditionally
+		// PoW is not required
+		return nil
+	}
+
+	var target, bestBit int
+	if options.PoW < 0 {
+		// target is not set - the function should run for a period
+		// of time specified in WorkTime param. Since we can predict
+		// the execution time, we can also adjust Expiry.
 		e.Expiry += options.WorkTime
 	} else {
 		target = e.powToFirstBit(options.PoW)
-		if target < 1 {
-			target = 1
-		}
 	}
 
 	buf := make([]byte, 64)
@@ -119,7 +103,7 @@ func (e *Envelope) Seal(options *MessageParams) error {
 			d := new(big.Int).SetBytes(crypto.Keccak256(buf))
 			firstBit := math.FirstBitSet(d)
 			if firstBit > bestBit {
-				e.EnvNonce, bestBit = nonce, firstBit
+				e.Nonce, bestBit = nonce, firstBit
 				if target > 0 && bestBit >= target {
 					return nil
 				}
@@ -135,6 +119,8 @@ func (e *Envelope) Seal(options *MessageParams) error {
 	return nil
 }
 
+// PoW computes (if necessary) and returns the proof of work target
+// of the envelope.
 func (e *Envelope) PoW() float64 {
 	if e.pow == 0 {
 		e.calculatePoW(0)
@@ -146,7 +132,7 @@ func (e *Envelope) calculatePoW(diff uint32) {
 	buf := make([]byte, 64)
 	h := crypto.Keccak256(e.rlpWithoutNonce())
 	copy(buf[:32], h)
-	binary.BigEndian.PutUint64(buf[56:], e.EnvNonce)
+	binary.BigEndian.PutUint64(buf[56:], e.Nonce)
 	d := new(big.Int).SetBytes(crypto.Keccak256(buf))
 	firstBit := math.FirstBitSet(d)
 	x := gmath.Pow(2, float64(firstBit))
@@ -161,7 +147,11 @@ func (e *Envelope) powToFirstBit(pow float64) int {
 	x *= float64(e.TTL)
 	bits := gmath.Log2(x)
 	bits = gmath.Ceil(bits)
-	return int(bits)
+	res := int(bits)
+	if res < 1 {
+		res = 1
+	}
+	return res
 }
 
 // Hash returns the SHA3 hash of the envelope, calculating it if not yet done.
@@ -209,7 +199,7 @@ func (e *Envelope) OpenAsymmetric(key *ecdsa.PrivateKey) (*ReceivedMessage, erro
 // OpenSymmetric tries to decrypt an envelope, potentially encrypted with a particular key.
 func (e *Envelope) OpenSymmetric(key []byte) (msg *ReceivedMessage, err error) {
 	msg = &ReceivedMessage{Raw: e.Data}
-	err = msg.decryptSymmetric(key, e.AESNonce)
+	err = msg.decryptSymmetric(key)
 	if err != nil {
 		msg = nil
 	}
@@ -218,12 +208,17 @@ func (e *Envelope) OpenSymmetric(key []byte) (msg *ReceivedMessage, err error) {
 
 // Open tries to decrypt an envelope, and populates the message fields in case of success.
 func (e *Envelope) Open(watcher *Filter) (msg *ReceivedMessage) {
-	if e.isAsymmetric() {
+	// The API interface forbids filters doing both symmetric and asymmetric encryption.
+	if watcher.expectsAsymmetricEncryption() && watcher.expectsSymmetricEncryption() {
+		return nil
+	}
+
+	if watcher.expectsAsymmetricEncryption() {
 		msg, _ = e.OpenAsymmetric(watcher.KeyAsym)
 		if msg != nil {
 			msg.Dst = &watcher.KeyAsym.PublicKey
 		}
-	} else if e.IsSymmetric() {
+	} else if watcher.expectsSymmetricEncryption() {
 		msg, _ = e.OpenSymmetric(watcher.KeySym)
 		if msg != nil {
 			msg.SymKeyHash = crypto.Keccak256Hash(watcher.KeySym)
@@ -231,7 +226,7 @@ func (e *Envelope) Open(watcher *Filter) (msg *ReceivedMessage) {
 	}
 
 	if msg != nil {
-		ok := msg.Validate()
+		ok := msg.ValidateAndParse()
 		if !ok {
 			return nil
 		}
@@ -240,7 +235,33 @@ func (e *Envelope) Open(watcher *Filter) (msg *ReceivedMessage) {
 		msg.TTL = e.TTL
 		msg.Sent = e.Expiry - e.TTL
 		msg.EnvelopeHash = e.Hash()
-		msg.EnvelopeVersion = e.Ver()
 	}
 	return msg
 }
+
+// Bloom maps 4-bytes Topic into 64-byte bloom filter with 3 bits set (at most).
+func (e *Envelope) Bloom() []byte {
+	if e.bloom == nil {
+		e.bloom = TopicToBloom(e.Topic)
+	}
+	return e.bloom
+}
+
+// TopicToBloom converts the topic (4 bytes) to the bloom filter (64 bytes)
+func TopicToBloom(topic TopicType) []byte {
+	b := make([]byte, bloomFilterSize)
+	var index [3]int
+	for j := 0; j < 3; j++ {
+		index[j] = int(topic[j])
+		if (topic[3] & (1 << uint(j))) != 0 {
+			index[j] += 256
+		}
+	}
+
+	for j := 0; j < 3; j++ {
+		byteIndex := index[j] / 8
+		bitIndex := index[j] % 8
+		b[byteIndex] = (1 << uint(bitIndex))
+	}
+	return b
+}

vendor/github.com/ethereum/go-ethereum/whisper/whisperv6/filter.go

@@ -26,6 +26,7 @@ import (
 	"github.com/ethereum/go-ethereum/log"
 )
 
+// Filter represents a Whisper message filter
 type Filter struct {
 	Src        *ecdsa.PublicKey  // Sender of the message
 	KeyAsym    *ecdsa.PrivateKey // Private Key of recipient
@@ -39,12 +40,14 @@ type Filter struct {
 	mutex    sync.RWMutex
 }
 
+// Filters represents a collection of filters
 type Filters struct {
 	watchers map[string]*Filter
 	whisper  *Whisper
 	mutex    sync.RWMutex
 }
 
+// NewFilters returns a newly created filter collection
 func NewFilters(w *Whisper) *Filters {
 	return &Filters{
 		watchers: make(map[string]*Filter),
@@ -52,7 +55,12 @@ func NewFilters(w *Whisper) *Filters {
 	}
 }
 
+// Install will add a new filter to the filter collection
 func (fs *Filters) Install(watcher *Filter) (string, error) {
+	if watcher.KeySym != nil && watcher.KeyAsym != nil {
+		return "", fmt.Errorf("filters must choose between symmetric and asymmetric keys")
+	}
+
 	if watcher.Messages == nil {
 		watcher.Messages = make(map[common.Hash]*ReceivedMessage)
 	}
@@ -77,6 +85,8 @@ func (fs *Filters) Install(watcher *Filter) (string, error) {
 	return id, err
 }
 
+// Uninstall will remove a filter whose id has been specified from
+// the filter collection
 func (fs *Filters) Uninstall(id string) bool {
 	fs.mutex.Lock()
 	defer fs.mutex.Unlock()
@@ -87,12 +97,15 @@ func (fs *Filters) Uninstall(id string) bool {
 	return false
 }
 
+// Get returns a filter from the collection with a specific ID
 func (fs *Filters) Get(id string) *Filter {
 	fs.mutex.RLock()
 	defer fs.mutex.RUnlock()
 	return fs.watchers[id]
 }
 
+// NotifyWatchers notifies any filter that has declared interest
+// for the envelope's topic.
 func (fs *Filters) NotifyWatchers(env *Envelope, p2pMessage bool) {
 	var msg *ReceivedMessage
 
@@ -136,9 +149,9 @@ func (f *Filter) processEnvelope(env *Envelope) *ReceivedMessage {
 		msg := env.Open(f)
 		if msg != nil {
 			return msg
-		} else {
-			log.Trace("processing envelope: failed to open", "hash", env.Hash().Hex())
 		}
+
+		log.Trace("processing envelope: failed to open", "hash", env.Hash().Hex())
 	} else {
 		log.Trace("processing envelope: does not match", "hash", env.Hash().Hex())
 	}
@@ -153,6 +166,8 @@ func (f *Filter) expectsSymmetricEncryption() bool {
 	return f.KeySym != nil
 }
 
+// Trigger adds a yet-unknown message to the filter's list of
+// received messages.
 func (f *Filter) Trigger(msg *ReceivedMessage) {
 	f.mutex.Lock()
 	defer f.mutex.Unlock()
@@ -162,6 +177,8 @@ func (f *Filter) Trigger(msg *ReceivedMessage) {
 	}
 }
 
+// Retrieve will return the list of all received messages associated
+// to a filter.
 func (f *Filter) Retrieve() (all []*ReceivedMessage) {
 	f.mutex.Lock()
 	defer f.mutex.Unlock()
@@ -175,6 +192,9 @@ func (f *Filter) Retrieve() (all []*ReceivedMessage) {
 	return all
 }
 
+// MatchMessage checks if the filter matches an already decrypted
+// message (i.e. a Message that has already been handled by
+// MatchEnvelope when checked by a previous filter)
 func (f *Filter) MatchMessage(msg *ReceivedMessage) bool {
 	if f.PoW > 0 && msg.PoW < f.PoW {
 		return false
@@ -188,19 +208,18 @@ func (f *Filter) MatchMessage(msg *ReceivedMessage) bool {
 	return false
 }
 
+// MatchEnvelope checks if it's worth decrypting the message. If
+// it returns `true`, client code is expected to attempt decrypting
+// the message and subsequently call MatchMessage.
 func (f *Filter) MatchEnvelope(envelope *Envelope) bool {
 	if f.PoW > 0 && envelope.pow < f.PoW {
 		return false
 	}
 
-	if f.expectsAsymmetricEncryption() && envelope.isAsymmetric() {
 	return f.MatchTopic(envelope.Topic)
-	} else if f.expectsSymmetricEncryption() && envelope.IsSymmetric() {
-		return f.MatchTopic(envelope.Topic)
-	}
-	return false
 }
 
+// MatchTopic checks that the filter captures a given topic.
 func (f *Filter) MatchTopic(topic TopicType) bool {
 	if len(f.Topics) == 0 {
 		// any topic matches
@@ -216,8 +235,12 @@ func (f *Filter) MatchTopic(topic TopicType) bool {
 }
 
 func matchSingleTopic(topic TopicType, bt []byte) bool {
-	if len(bt) > 4 {
-		bt = bt[:4]
+	if len(bt) > TopicLength {
+		bt = bt[:TopicLength]
+	}
+
+	if len(bt) < TopicLength {
+		return false
 	}
 
 	for j, b := range bt {
@@ -228,6 +251,7 @@ func matchSingleTopic(topic TopicType, bt []byte) bool {
 	return true
 }
 
+// IsPubKeyEqual checks that two public keys are equal
 func IsPubKeyEqual(a, b *ecdsa.PublicKey) bool {
 	if !ValidatePublicKey(a) {
 		return false

vendor/github.com/ethereum/go-ethereum/whisper/whisperv6/gen_criteria_json.go

@@ -10,6 +10,7 @@ import (
 
 var _ = (*criteriaOverride)(nil)
 
+// MarshalJSON marshals type Criteria to a json string
 func (c Criteria) MarshalJSON() ([]byte, error) {
 	type Criteria struct {
 		SymKeyID     string        `json:"symKeyID"`
@@ -29,11 +30,12 @@ func (c Criteria) MarshalJSON() ([]byte, error) {
 	return json.Marshal(&enc)
 }
 
+// UnmarshalJSON unmarshals type Criteria to a json string
 func (c *Criteria) UnmarshalJSON(input []byte) error {
 	type Criteria struct {
 		SymKeyID     *string        `json:"symKeyID"`
 		PrivateKeyID *string        `json:"privateKeyID"`
-		Sig          hexutil.Bytes `json:"sig"`
+		Sig          *hexutil.Bytes `json:"sig"`
 		MinPow       *float64       `json:"minPow"`
 		Topics       []TopicType    `json:"topics"`
 		AllowP2P     *bool          `json:"allowP2P"`
@@ -49,7 +51,7 @@ func (c *Criteria) UnmarshalJSON(input []byte) error {
 		c.PrivateKeyID = *dec.PrivateKeyID
 	}
 	if dec.Sig != nil {
-		c.Sig = dec.Sig
+		c.Sig = *dec.Sig
 	}
 	if dec.MinPow != nil {
 		c.MinPow = *dec.MinPow

vendor/github.com/ethereum/go-ethereum/whisper/whisperv6/gen_message_json.go

@@ -10,6 +10,7 @@ import (
 
 var _ = (*messageOverride)(nil)
 
+// MarshalJSON marshals type Message to a json string
 func (m Message) MarshalJSON() ([]byte, error) {
 	type Message struct {
 		Sig       hexutil.Bytes `json:"sig,omitempty"`
@@ -35,24 +36,25 @@ func (m Message) MarshalJSON() ([]byte, error) {
 	return json.Marshal(&enc)
 }
 
+// UnmarshalJSON unmarshals type Message to a json string
 func (m *Message) UnmarshalJSON(input []byte) error {
 	type Message struct {
-		Sig       hexutil.Bytes `json:"sig,omitempty"`
+		Sig       *hexutil.Bytes `json:"sig,omitempty"`
 		TTL       *uint32        `json:"ttl"`
 		Timestamp *uint32        `json:"timestamp"`
 		Topic     *TopicType     `json:"topic"`
-		Payload   hexutil.Bytes `json:"payload"`
-		Padding   hexutil.Bytes `json:"padding"`
+		Payload   *hexutil.Bytes `json:"payload"`
+		Padding   *hexutil.Bytes `json:"padding"`
 		PoW       *float64       `json:"pow"`
-		Hash      hexutil.Bytes `json:"hash"`
-		Dst       hexutil.Bytes `json:"recipientPublicKey,omitempty"`
+		Hash      *hexutil.Bytes `json:"hash"`
+		Dst       *hexutil.Bytes `json:"recipientPublicKey,omitempty"`
 	}
 	var dec Message
 	if err := json.Unmarshal(input, &dec); err != nil {
 		return err
 	}
 	if dec.Sig != nil {
-		m.Sig = dec.Sig
+		m.Sig = *dec.Sig
 	}
 	if dec.TTL != nil {
 		m.TTL = *dec.TTL
@@ -64,19 +66,19 @@ func (m *Message) UnmarshalJSON(input []byte) error {
 		m.Topic = *dec.Topic
 	}
 	if dec.Payload != nil {
-		m.Payload = dec.Payload
+		m.Payload = *dec.Payload
 	}
 	if dec.Padding != nil {
-		m.Padding = dec.Padding
+		m.Padding = *dec.Padding
 	}
 	if dec.PoW != nil {
 		m.PoW = *dec.PoW
 	}
 	if dec.Hash != nil {
-		m.Hash = dec.Hash
+		m.Hash = *dec.Hash
 	}
 	if dec.Dst != nil {
-		m.Dst = dec.Dst
+		m.Dst = *dec.Dst
 	}
 	return nil
 }

vendor/github.com/ethereum/go-ethereum/whisper/whisperv6/gen_newmessage_json.go

@@ -10,6 +10,7 @@ import (
 
 var _ = (*newMessageOverride)(nil)
 
+// MarshalJSON marshals type NewMessage to a json string
 func (n NewMessage) MarshalJSON() ([]byte, error) {
 	type NewMessage struct {
 		SymKeyID   string        `json:"symKeyID"`
@@ -37,15 +38,16 @@ func (n NewMessage) MarshalJSON() ([]byte, error) {
 	return json.Marshal(&enc)
 }
 
+// UnmarshalJSON unmarshals type NewMessage to a json string
 func (n *NewMessage) UnmarshalJSON(input []byte) error {
 	type NewMessage struct {
 		SymKeyID   *string        `json:"symKeyID"`
-		PublicKey  hexutil.Bytes `json:"pubKey"`
+		PublicKey  *hexutil.Bytes `json:"pubKey"`
 		Sig        *string        `json:"sig"`
 		TTL        *uint32        `json:"ttl"`
 		Topic      *TopicType     `json:"topic"`
-		Payload    hexutil.Bytes `json:"payload"`
-		Padding    hexutil.Bytes `json:"padding"`
+		Payload    *hexutil.Bytes `json:"payload"`
+		Padding    *hexutil.Bytes `json:"padding"`
 		PowTime    *uint32        `json:"powTime"`
 		PowTarget  *float64       `json:"powTarget"`
 		TargetPeer *string        `json:"targetPeer"`
@@ -58,7 +60,7 @@ func (n *NewMessage) UnmarshalJSON(input []byte) error {
 		n.SymKeyID = *dec.SymKeyID
 	}
 	if dec.PublicKey != nil {
-		n.PublicKey = dec.PublicKey
+		n.PublicKey = *dec.PublicKey
 	}
 	if dec.Sig != nil {
 		n.Sig = *dec.Sig
@@ -70,10 +72,10 @@ func (n *NewMessage) UnmarshalJSON(input []byte) error {
 		n.Topic = *dec.Topic
 	}
 	if dec.Payload != nil {
-		n.Payload = dec.Payload
+		n.Payload = *dec.Payload
 	}
 	if dec.Padding != nil {
-		n.Padding = dec.Padding
+		n.Padding = *dec.Padding
 	}
 	if dec.PowTime != nil {
 		n.PowTime = *dec.PowTime

vendor/github.com/ethereum/go-ethereum/whisper/whisperv6/message.go

@@ -25,6 +25,7 @@ import (
 	crand "crypto/rand"
 	"encoding/binary"
 	"errors"
+	mrand "math/rand"
 	"strconv"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -33,7 +34,8 @@ import (
 	"github.com/ethereum/go-ethereum/log"
 )
 
-// Options specifies the exact way a message should be wrapped into an Envelope.
+// MessageParams specifies the exact way a message should be wrapped
+// into an Envelope.
 type MessageParams struct {
 	TTL      uint32
 	Src      *ecdsa.PrivateKey
@@ -54,13 +56,14 @@ type sentMessage struct {
 }
 
 // ReceivedMessage represents a data packet to be received through the
-// Whisper protocol.
+// Whisper protocol and successfully decrypted.
 type ReceivedMessage struct {
 	Raw []byte
 
 	Payload   []byte
 	Padding   []byte
 	Signature []byte
+	Salt      []byte
 
 	PoW   float64          // Proof of work as described in the Whisper spec
 	Sent  uint32           // Time when the message was posted into the network
@@ -69,9 +72,8 @@ type ReceivedMessage struct {
 	Dst   *ecdsa.PublicKey // Message recipient (identity used to decode the message)
 	Topic TopicType
 
-	SymKeyHash      common.Hash // The Keccak256Hash of the key, associated with the Topic
+	SymKeyHash   common.Hash // The Keccak256Hash of the key
 	EnvelopeHash common.Hash // Message envelope hash to act as a unique id
-	EnvelopeVersion uint64
 }
 
 func isMessageSigned(flags byte) bool {
@@ -86,79 +88,62 @@ func (msg *ReceivedMessage) isAsymmetricEncryption() bool {
 	return msg.Dst != nil
 }
 
-// NewMessage creates and initializes a non-signed, non-encrypted Whisper message.
+// NewSentMessage creates and initializes a non-signed, non-encrypted Whisper message.
 func NewSentMessage(params *MessageParams) (*sentMessage, error) {
+	const payloadSizeFieldMaxSize = 4
 	msg := sentMessage{}
-	msg.Raw = make([]byte, 1, len(params.Payload)+len(params.Padding)+signatureLength+padSizeLimit)
+	msg.Raw = make([]byte, 1,
+		flagsLength+payloadSizeFieldMaxSize+len(params.Payload)+len(params.Padding)+signatureLength+padSizeLimit)
 	msg.Raw[0] = 0 // set all the flags to zero
-	err := msg.appendPadding(params)
-	if err != nil {
-		return nil, err
-	}
+	msg.addPayloadSizeField(params.Payload)
 	msg.Raw = append(msg.Raw, params.Payload...)
-	return &msg, nil
+	err := msg.appendPadding(params)
+	return &msg, err
 }
 
-// getSizeOfLength returns the number of bytes necessary to encode the entire size padding (including these bytes)
-func getSizeOfLength(b []byte) (sz int, err error) {
-	sz = intSize(len(b))      // first iteration
-	sz = intSize(len(b) + sz) // second iteration
-	if sz > 3 {
-		err = errors.New("oversized padding parameter")
-	}
-	return sz, err
+// addPayloadSizeField appends the auxiliary field containing the size of payload
+func (msg *sentMessage) addPayloadSizeField(payload []byte) {
+	fieldSize := getSizeOfPayloadSizeField(payload)
+	field := make([]byte, 4)
+	binary.LittleEndian.PutUint32(field, uint32(len(payload)))
+	field = field[:fieldSize]
+	msg.Raw = append(msg.Raw, field...)
+	msg.Raw[0] |= byte(fieldSize)
 }
 
-// sizeOfIntSize returns minimal number of bytes necessary to encode an integer value
-func intSize(i int) (s int) {
-	for s = 1; i >= 256; s++ {
-		i /= 256
+// getSizeOfPayloadSizeField returns the number of bytes necessary to encode the size of payload
+func getSizeOfPayloadSizeField(payload []byte) int {
+	s := 1
+	for i := len(payload); i >= 256; i /= 256 {
+		s++
 	}
 	return s
 }
 
-// appendPadding appends the pseudorandom padding bytes and sets the padding flag.
-// The last byte contains the size of padding (thus, its size must not exceed 256).
+// appendPadding appends the padding specified in params.
+// If no padding is provided in params, then random padding is generated.
 func (msg *sentMessage) appendPadding(params *MessageParams) error {
-	rawSize := len(params.Payload) + 1
+	if len(params.Padding) != 0 {
+		// padding data was provided by the Dapp, just use it as is
+		msg.Raw = append(msg.Raw, params.Padding...)
+		return nil
+	}
+
+	rawSize := flagsLength + getSizeOfPayloadSizeField(params.Payload) + len(params.Payload)
 	if params.Src != nil {
 		rawSize += signatureLength
 	}
 	odd := rawSize % padSizeLimit
-
-	if len(params.Padding) != 0 {
-		padSize := len(params.Padding)
-		padLengthSize, err := getSizeOfLength(params.Padding)
+	paddingSize := padSizeLimit - odd
+	pad := make([]byte, paddingSize)
+	_, err := crand.Read(pad)
 	if err != nil {
 		return err
 	}
-		totalPadSize := padSize + padLengthSize
-		buf := make([]byte, 8)
-		binary.LittleEndian.PutUint32(buf, uint32(totalPadSize))
-		buf = buf[:padLengthSize]
-		msg.Raw = append(msg.Raw, buf...)
-		msg.Raw = append(msg.Raw, params.Padding...)
-		msg.Raw[0] |= byte(padLengthSize) // number of bytes indicating the padding size
-	} else if odd != 0 {
-		totalPadSize := padSizeLimit - odd
-		if totalPadSize > 255 {
-			// this algorithm is only valid if padSizeLimit < 256.
-			// if padSizeLimit will ever change, please fix the algorithm
-			// (please see also ReceivedMessage.extractPadding() function).
-			panic("please fix the padding algorithm before releasing new version")
-		}
-		buf := make([]byte, totalPadSize)
-		_, err := crand.Read(buf[1:])
-		if err != nil {
-			return err
-		}
-		if totalPadSize > 6 && !validateSymmetricKey(buf) {
-			return errors.New("failed to generate random padding of size " + strconv.Itoa(totalPadSize))
-		}
-		buf[0] = byte(totalPadSize)
-		msg.Raw = append(msg.Raw, buf...)
-		msg.Raw[0] |= byte(0x1) // number of bytes indicating the padding size
+	if !validateDataIntegrity(pad, paddingSize) {
+		return errors.New("failed to generate random padding of size " + strconv.Itoa(paddingSize))
 	}
+	msg.Raw = append(msg.Raw, pad...)
 	return nil
 }
 
@@ -171,11 +156,11 @@ func (msg *sentMessage) sign(key *ecdsa.PrivateKey) error {
 		return nil
 	}
 
-	msg.Raw[0] |= signatureFlag
+	msg.Raw[0] |= signatureFlag // it is important to set this flag before signing
 	hash := crypto.Keccak256(msg.Raw)
 	signature, err := crypto.Sign(hash, key)
 	if err != nil {
-		msg.Raw[0] &= ^signatureFlag // clear the flag
+		msg.Raw[0] &= (0xFF ^ signatureFlag) // clear the flag
 		return err
 	}
 	msg.Raw = append(msg.Raw, signature...)
@@ -196,31 +181,56 @@ func (msg *sentMessage) encryptAsymmetric(key *ecdsa.PublicKey) error {
 
 // encryptSymmetric encrypts a message with a topic key, using AES-GCM-256.
 // nonce size should be 12 bytes (see cipher.gcmStandardNonceSize).
-func (msg *sentMessage) encryptSymmetric(key []byte) (nonce []byte, err error) {
-	if !validateSymmetricKey(key) {
-		return nil, errors.New("invalid key provided for symmetric encryption")
+func (msg *sentMessage) encryptSymmetric(key []byte) (err error) {
+	if !validateDataIntegrity(key, aesKeyLength) {
+		return errors.New("invalid key provided for symmetric encryption, size: " + strconv.Itoa(len(key)))
 	}
-
 	block, err := aes.NewCipher(key)
 	if err != nil {
-		return nil, err
+		return err
 	}
 	aesgcm, err := cipher.NewGCM(block)
 	if err != nil {
-		return nil, err
+		return err
+	}
+	salt, err := generateSecureRandomData(aesNonceLength) // never use more than 2^32 random nonces with a given key
+	if err != nil {
+		return err
+	}
+	encrypted := aesgcm.Seal(nil, salt, msg.Raw, nil)
+	msg.Raw = append(encrypted, salt...)
+	return nil
 }
 
-	// never use more than 2^32 random nonces with a given key
-	nonce = make([]byte, aesgcm.NonceSize())
-	_, err = crand.Read(nonce)
+// generateSecureRandomData generates random data where extra security is required.
+// The purpose of this function is to prevent some bugs in software or in hardware
+// from delivering not-very-random data. This is especially useful for AES nonce,
+// where true randomness does not really matter, but it is very important to have
+// a unique nonce for every message.
+func generateSecureRandomData(length int) ([]byte, error) {
+	x := make([]byte, length)
+	y := make([]byte, length)
+	res := make([]byte, length)
+
+	_, err := crand.Read(x)
 	if err != nil {
 		return nil, err
-	} else if !validateSymmetricKey(nonce) {
-		return nil, errors.New("crypto/rand failed to generate nonce")
+	} else if !validateDataIntegrity(x, length) {
+		return nil, errors.New("crypto/rand failed to generate secure random data")
 	}
-
-	msg.Raw = aesgcm.Seal(nil, nonce, msg.Raw, nil)
-	return nonce, nil
+	_, err = mrand.Read(y)
+	if err != nil {
+		return nil, err
+	} else if !validateDataIntegrity(y, length) {
+		return nil, errors.New("math/rand failed to generate secure random data")
+	}
+	for i := 0; i < length; i++ {
+		res[i] = x[i] ^ y[i]
+	}
+	if !validateDataIntegrity(res, length) {
+		return nil, errors.New("failed to generate secure random data")
+	}
+	return res, nil
 }
 
 // Wrap bundles the message into an Envelope to transmit over the network.
@@ -233,11 +243,10 @@ func (msg *sentMessage) Wrap(options *MessageParams) (envelope *Envelope, err er
 			return nil, err
 		}
 	}
-	var nonce []byte
 	if options.Dst != nil {
 		err = msg.encryptAsymmetric(options.Dst)
 	} else if options.KeySym != nil {
-		nonce, err = msg.encryptSymmetric(options.KeySym)
+		err = msg.encryptSymmetric(options.KeySym)
 	} else {
 		err = errors.New("unable to encrypt the message: neither symmetric nor assymmetric key provided")
 	}
@@ -245,7 +254,7 @@ func (msg *sentMessage) Wrap(options *MessageParams) (envelope *Envelope, err er
 		return nil, err
 	}
 
-	envelope = NewEnvelope(options.TTL, options.Topic, nonce, msg)
+	envelope = NewEnvelope(options.TTL, options.Topic, msg)
 	if err = envelope.Seal(options); err != nil {
 		return nil, err
 	}
@@ -254,7 +263,13 @@ func (msg *sentMessage) Wrap(options *MessageParams) (envelope *Envelope, err er
 
 // decryptSymmetric decrypts a message with a topic key, using AES-GCM-256.
 // nonce size should be 12 bytes (see cipher.gcmStandardNonceSize).
-func (msg *ReceivedMessage) decryptSymmetric(key []byte, nonce []byte) error {
+func (msg *ReceivedMessage) decryptSymmetric(key []byte) error {
+	// symmetric messages are expected to contain the 12-byte nonce at the end of the payload
+	if len(msg.Raw) < aesNonceLength {
+		return errors.New("missing salt or invalid payload in symmetric message")
+	}
+	salt := msg.Raw[len(msg.Raw)-aesNonceLength:]
+
 	block, err := aes.NewCipher(key)
 	if err != nil {
 		return err
@@ -263,15 +278,12 @@ func (msg *ReceivedMessage) decryptSymmetric(key []byte, nonce []byte) error {
 	if err != nil {
 		return err
 	}
-	if len(nonce) != aesgcm.NonceSize() {
-		log.Error("decrypting the message", "AES nonce size", len(nonce))
-		return errors.New("wrong AES nonce size")
-	}
-	decrypted, err := aesgcm.Open(nil, nonce, msg.Raw, nil)
+	decrypted, err := aesgcm.Open(nil, salt, msg.Raw[:len(msg.Raw)-aesNonceLength], nil)
 	if err != nil {
 		return err
 	}
 	msg.Raw = decrypted
+	msg.Salt = salt
 	return nil
 }
 
@@ -284,8 +296,8 @@ func (msg *ReceivedMessage) decryptAsymmetric(key *ecdsa.PrivateKey) error {
 	return err
 }
 
-// Validate checks the validity and extracts the fields in case of success
-func (msg *ReceivedMessage) Validate() bool {
+// ValidateAndParse checks the message validity and extracts the fields in case of success.
+func (msg *ReceivedMessage) ValidateAndParse() bool {
 	end := len(msg.Raw)
 	if end < 1 {
 		return false
@@ -296,41 +308,32 @@ func (msg *ReceivedMessage) Validate() bool {
 		if end <= 1 {
 			return false
 		}
-		msg.Signature = msg.Raw[end:]
+		msg.Signature = msg.Raw[end : end+signatureLength]
 		msg.Src = msg.SigToPubKey()
 		if msg.Src == nil {
 			return false
 		}
 	}
 
-	padSize, ok := msg.extractPadding(end)
-	if !ok {
+	beg := 1
+	payloadSize := 0
+	sizeOfPayloadSizeField := int(msg.Raw[0] & SizeMask) // number of bytes indicating the size of payload
+	if sizeOfPayloadSizeField != 0 {
+		payloadSize = int(bytesToUintLittleEndian(msg.Raw[beg : beg+sizeOfPayloadSizeField]))
+		if payloadSize+1 > end {
 			return false
 		}
+		beg += sizeOfPayloadSizeField
+		msg.Payload = msg.Raw[beg : beg+payloadSize]
+	}
 
-	msg.Payload = msg.Raw[1+padSize : end]
+	beg += payloadSize
+	msg.Padding = msg.Raw[beg:end]
 	return true
 }
 
-// extractPadding extracts the padding from raw message.
-// although we don't support sending messages with padding size
-// exceeding 255 bytes, such messages are perfectly valid, and
-// can be successfully decrypted.
-func (msg *ReceivedMessage) extractPadding(end int) (int, bool) {
-	paddingSize := 0
-	sz := int(msg.Raw[0] & paddingMask) // number of bytes indicating the entire size of padding (including these bytes)
-	// could be zero -- it means no padding
-	if sz != 0 {
-		paddingSize = int(bytesToUintLittleEndian(msg.Raw[1 : 1+sz]))
-		if paddingSize < sz || paddingSize+1 > end {
-			return 0, false
-		}
-		msg.Padding = msg.Raw[1+sz : 1+paddingSize]
-	}
-	return paddingSize, true
-}
-
-// Recover retrieves the public key of the message signer.
+// SigToPubKey returns the public key associated to the message's
+// signature.
 func (msg *ReceivedMessage) SigToPubKey() *ecdsa.PublicKey {
 	defer func() { recover() }() // in case of invalid signature
 
@@ -342,7 +345,7 @@ func (msg *ReceivedMessage) SigToPubKey() *ecdsa.PublicKey {
 	return pub
 }
 
-// hash calculates the SHA3 checksum of the message flags, payload and padding.
+// hash calculates the SHA3 checksum of the message flags, payload size field, payload and padding.
 func (msg *ReceivedMessage) hash() []byte {
 	if isMessageSigned(msg.Raw[0]) {
 		sz := len(msg.Raw) - signatureLength

vendor/github.com/ethereum/go-ethereum/whisper/whisperv6/peer.go

@@ -18,6 +18,7 @@ package whisperv6
 
 import (
 	"fmt"
+	"math"
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
@@ -27,12 +28,16 @@ import (
 	set "gopkg.in/fatih/set.v0"
 )
 
-// peer represents a whisper protocol peer connection.
+// Peer represents a whisper protocol peer connection.
 type Peer struct {
 	host *Whisper
 	peer *p2p.Peer
 	ws   p2p.MsgReadWriter
+
 	trusted        bool
+	powRequirement float64
+	bloomFilter    []byte
+	fullNode       bool
 
 	known *set.Set // Messages already known by the peer to avoid wasting bandwidth
 
@@ -46,58 +51,89 @@ func newPeer(host *Whisper, remote *p2p.Peer, rw p2p.MsgReadWriter) *Peer {
 		peer:           remote,
 		ws:             rw,
 		trusted:        false,
+		powRequirement: 0.0,
 		known:          set.New(),
 		quit:           make(chan struct{}),
+		bloomFilter:    makeFullNodeBloom(),
+		fullNode:       true,
 	}
 }
 
 // start initiates the peer updater, periodically broadcasting the whisper packets
 // into the network.
-func (p *Peer) start() {
-	go p.update()
-	log.Trace("start", "peer", p.ID())
+func (peer *Peer) start() {
+	go peer.update()
+	log.Trace("start", "peer", peer.ID())
 }
 
 // stop terminates the peer updater, stopping message forwarding to it.
-func (p *Peer) stop() {
-	close(p.quit)
-	log.Trace("stop", "peer", p.ID())
+func (peer *Peer) stop() {
+	close(peer.quit)
+	log.Trace("stop", "peer", peer.ID())
 }
 
 // handshake sends the protocol initiation status message to the remote peer and
 // verifies the remote status too.
-func (p *Peer) handshake() error {
+func (peer *Peer) handshake() error {
 	// Send the handshake status message asynchronously
 	errc := make(chan error, 1)
 	go func() {
-		errc <- p2p.Send(p.ws, statusCode, ProtocolVersion)
+		pow := peer.host.MinPow()
+		powConverted := math.Float64bits(pow)
+		bloom := peer.host.BloomFilter()
+		errc <- p2p.SendItems(peer.ws, statusCode, ProtocolVersion, powConverted, bloom)
 	}()
+
 	// Fetch the remote status packet and verify protocol match
-	packet, err := p.ws.ReadMsg()
+	packet, err := peer.ws.ReadMsg()
 	if err != nil {
 		return err
 	}
 	if packet.Code != statusCode {
-		return fmt.Errorf("peer [%x] sent packet %x before status packet", p.ID(), packet.Code)
+		return fmt.Errorf("peer [%x] sent packet %x before status packet", peer.ID(), packet.Code)
 	}
 	s := rlp.NewStream(packet.Payload, uint64(packet.Size))
+	_, err = s.List()
+	if err != nil {
+		return fmt.Errorf("peer [%x] sent bad status message: %v", peer.ID(), err)
+	}
 	peerVersion, err := s.Uint()
 	if err != nil {
-		return fmt.Errorf("peer [%x] sent bad status message: %v", p.ID(), err)
+		return fmt.Errorf("peer [%x] sent bad status message (unable to decode version): %v", peer.ID(), err)
 	}
 	if peerVersion != ProtocolVersion {
-		return fmt.Errorf("peer [%x]: protocol version mismatch %d != %d", p.ID(), peerVersion, ProtocolVersion)
+		return fmt.Errorf("peer [%x]: protocol version mismatch %d != %d", peer.ID(), peerVersion, ProtocolVersion)
 	}
-	// Wait until out own status is consumed too
+
+	// only version is mandatory, subsequent parameters are optional
+	powRaw, err := s.Uint()
+	if err == nil {
+		pow := math.Float64frombits(powRaw)
+		if math.IsInf(pow, 0) || math.IsNaN(pow) || pow < 0.0 {
+			return fmt.Errorf("peer [%x] sent bad status message: invalid pow", peer.ID())
+		}
+		peer.powRequirement = pow
+
+		var bloom []byte
+		err = s.Decode(&bloom)
+		if err == nil {
+			sz := len(bloom)
+			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)
+		}
+	}
+
 	if err := <-errc; err != nil {
-		return fmt.Errorf("peer [%x] failed to send status packet: %v", p.ID(), err)
+		return fmt.Errorf("peer [%x] failed to send status packet: %v", peer.ID(), err)
 	}
 	return nil
 }
 
 // update executes periodic operations on the peer, including message transmission
 // and expiration.
-func (p *Peer) update() {
+func (peer *Peer) update() {
 	// Start the tickers for the updates
 	expire := time.NewTicker(expirationCycle)
 	transmit := time.NewTicker(transmissionCycle)
@@ -106,15 +142,15 @@ func (p *Peer) update() {
 	for {
 		select {
 		case <-expire.C:
-			p.expire()
+			peer.expire()
 
 		case <-transmit.C:
-			if err := p.broadcast(); err != nil {
-				log.Trace("broadcast failed", "reason", err, "peer", p.ID())
+			if err := peer.broadcast(); err != nil {
+				log.Trace("broadcast failed", "reason", err, "peer", peer.ID())
 				return
 			}
 
-		case <-p.quit:
+		case <-peer.quit:
 			return
 		}
 	}
@@ -148,27 +184,62 @@ func (peer *Peer) expire() {
 
 // broadcast iterates over the collection of envelopes and transmits yet unknown
 // ones over the network.
-func (p *Peer) broadcast() error {
-	var cnt int
-	envelopes := p.host.Envelopes()
+func (peer *Peer) broadcast() error {
+	envelopes := peer.host.Envelopes()
+	bundle := make([]*Envelope, 0, len(envelopes))
 	for _, envelope := range envelopes {
-		if !p.marked(envelope) {
-			err := p2p.Send(p.ws, messagesCode, envelope)
-			if err != nil {
+		if !peer.marked(envelope) && envelope.PoW() >= peer.powRequirement && peer.bloomMatch(envelope) {
+			bundle = append(bundle, envelope)
+		}
+	}
+
+	if len(bundle) > 0 {
+		// transmit the batch of envelopes
+		if err := p2p.Send(peer.ws, messagesCode, bundle); err != nil {
 			return err
-			} else {
-				p.mark(envelope)
-				cnt++
 		}
+
+		// mark envelopes only if they were successfully sent
+		for _, e := range bundle {
+			peer.mark(e)
 		}
-	}
-	if cnt > 0 {
-		log.Trace("broadcast", "num. messages", cnt)
+
+		log.Trace("broadcast", "num. messages", len(bundle))
 	}
 	return nil
 }
 
-func (p *Peer) ID() []byte {
-	id := p.peer.ID()
+// ID returns a peer's id
+func (peer *Peer) ID() []byte {
+	id := peer.peer.ID()
 	return id[:]
 }
+
+func (peer *Peer) notifyAboutPowRequirementChange(pow float64) error {
+	i := math.Float64bits(pow)
+	return p2p.Send(peer.ws, powRequirementCode, i)
+}
+
+func (peer *Peer) notifyAboutBloomFilterChange(bloom []byte) error {
+	return p2p.Send(peer.ws, bloomFilterExCode, bloom)
+}
+
+func (peer *Peer) bloomMatch(env *Envelope) bool {
+	return peer.fullNode || bloomFilterMatch(peer.bloomFilter, env.Bloom())
+}
+
+func (peer *Peer) setBloomFilter(bloom []byte) {
+	peer.bloomFilter = bloom
+	peer.fullNode = isFullNode(bloom)
+	if peer.fullNode && peer.bloomFilter == nil {
+		peer.bloomFilter = makeFullNodeBloom()
+	}
+}
+
+func makeFullNodeBloom() []byte {
+	bloom := make([]byte, bloomFilterSize)
+	for i := 0; i < bloomFilterSize; i++ {
+		bloom[i] = 0xFF
+	}
+	return bloom
+}

vendor/github.com/ethereum/go-ethereum/whisper/whisperv6/topic.go

@@ -23,11 +23,13 @@ import (
 	"github.com/ethereum/go-ethereum/common/hexutil"
 )
 
-// Topic represents a cryptographically secure, probabilistic partial
+// TopicType represents a cryptographically secure, probabilistic partial
 // classifications of a message, determined as the first (left) 4 bytes of the
 // SHA3 hash of some arbitrary data given by the original author of the message.
 type TopicType [TopicLength]byte
 
+// BytesToTopic converts from the byte array representation of a topic
+// into the TopicType type.
 func BytesToTopic(b []byte) (t TopicType) {
 	sz := TopicLength
 	if x := len(b); x < TopicLength {