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message_processor.go
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message_processor.go
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package common
import (
"context"
"crypto/ecdsa"
"database/sql"
"sync"
"time"
"github.com/golang/protobuf/proto"
"github.com/pkg/errors"
datasyncnode "github.com/vacp2p/mvds/node"
datasyncproto "github.com/vacp2p/mvds/protobuf"
"go.uber.org/zap"
"github.com/status-im/status-go/eth-node/crypto"
"github.com/status-im/status-go/eth-node/types"
"github.com/status-im/status-go/protocol/datasync"
datasyncpeer "github.com/status-im/status-go/protocol/datasync/peer"
"github.com/status-im/status-go/protocol/encryption"
"github.com/status-im/status-go/protocol/encryption/sharedsecret"
"github.com/status-im/status-go/protocol/protobuf"
"github.com/status-im/status-go/protocol/transport"
v1protocol "github.com/status-im/status-go/protocol/v1"
)
// Whisper message properties.
const (
whisperTTL = 15
whisperDefaultPoW = 0.002
// whisperLargeSizePoW is the PoWTarget for larger payload sizes
whisperLargeSizePoW = 0.000002
// largeSizeInBytes is when should we be using a lower POW.
// Roughly this is 50KB
largeSizeInBytes = 50000
whisperPoWTime = 5
)
// SentMessage reprent a message that has been passed to the transport layer
type SentMessage struct {
PublicKey *ecdsa.PublicKey
Spec *encryption.ProtocolMessageSpec
MessageIDs [][]byte
}
type MessageProcessor struct {
identity *ecdsa.PrivateKey
datasync *datasync.DataSync
protocol *encryption.Protocol
transport transport.Transport
logger *zap.Logger
// ephemeralKeys is a map that contains the ephemeral keys of the client, used
// to decrypt messages
ephemeralKeys map[string]*ecdsa.PrivateKey
ephemeralKeysMutex sync.Mutex
// sentMessagesSubscriptions contains all the subscriptions for sent messages
sentMessagesSubscriptions []chan<- *SentMessage
// sentMessagesSubscriptions contains all the subscriptions for scheduled messages
scheduledMessagesSubscriptions []chan<- *RawMessage
featureFlags FeatureFlags
// handleSharedSecrets is a callback that is called every time a new shared secret is negotiated
handleSharedSecrets func([]*sharedsecret.Secret) error
}
func NewMessageProcessor(
identity *ecdsa.PrivateKey,
database *sql.DB,
enc *encryption.Protocol,
transport transport.Transport,
logger *zap.Logger,
features FeatureFlags,
) (*MessageProcessor, error) {
dataSyncTransport := datasync.NewNodeTransport()
dataSyncNode, err := datasyncnode.NewPersistentNode(
database,
dataSyncTransport,
datasyncpeer.PublicKeyToPeerID(identity.PublicKey),
datasyncnode.BATCH,
datasync.CalculateSendTime,
logger,
)
if err != nil {
return nil, err
}
ds := datasync.New(dataSyncNode, dataSyncTransport, features.Datasync, logger)
p := &MessageProcessor{
identity: identity,
datasync: ds,
protocol: enc,
transport: transport,
logger: logger,
ephemeralKeys: make(map[string]*ecdsa.PrivateKey),
featureFlags: features,
}
// Initializing DataSync is required to encrypt and send messages.
// With DataSync enabled, messages are added to the DataSync
// but actual encrypt and send calls are postponed.
// sendDataSync is responsible for encrypting and sending postponed messages.
if features.Datasync {
ds.Init(p.sendDataSync)
ds.Start(300 * time.Millisecond)
}
return p, nil
}
func (p *MessageProcessor) Stop() {
for _, c := range p.sentMessagesSubscriptions {
close(c)
}
p.sentMessagesSubscriptions = nil
p.datasync.Stop() // idempotent op
}
func (p *MessageProcessor) SetHandleSharedSecrets(handler func([]*sharedsecret.Secret) error) {
p.handleSharedSecrets = handler
}
// SendPrivate takes encoded data, encrypts it and sends through the wire.
func (p *MessageProcessor) SendPrivate(
ctx context.Context,
recipient *ecdsa.PublicKey,
rawMessage RawMessage,
) ([]byte, error) {
p.logger.Debug(
"sending a private message",
zap.String("public-key", types.EncodeHex(crypto.FromECDSAPub(recipient))),
zap.String("site", "SendPrivate"),
)
// Currently we don't support sending through datasync and setting custom waku fields,
// as the datasync interface is not rich enough to propagate that information, so we
// would have to add some complexity to handle this.
if rawMessage.ResendAutomatically && (rawMessage.Sender != nil || rawMessage.SkipEncryption) {
return nil, errors.New("setting identity, skip-encryption and datasync not supported")
}
// Set sender identity if not specified
if rawMessage.Sender == nil {
rawMessage.Sender = p.identity
}
return p.sendPrivate(ctx, recipient, &rawMessage)
}
// SendGroup takes encoded data, encrypts it and sends through the wire,
// always return the messageID
func (p *MessageProcessor) SendGroup(
ctx context.Context,
recipients []*ecdsa.PublicKey,
rawMessage RawMessage,
) ([]byte, error) {
p.logger.Debug(
"sending a private group message",
zap.String("site", "SendGroup"),
)
// Set sender if not specified
if rawMessage.Sender == nil {
rawMessage.Sender = p.identity
}
// Calculate messageID first and set on raw message
wrappedMessage, err := p.wrapMessageV1(&rawMessage)
if err != nil {
return nil, errors.Wrap(err, "failed to wrap message")
}
messageID := v1protocol.MessageID(&rawMessage.Sender.PublicKey, wrappedMessage)
rawMessage.ID = types.EncodeHex(messageID)
// Send to each recipients
for _, recipient := range recipients {
_, err = p.sendPrivate(ctx, recipient, &rawMessage)
if err != nil {
return nil, errors.Wrap(err, "failed to send message")
}
}
return messageID, nil
}
// sendPrivate sends data to the recipient identifying with a given public key.
func (p *MessageProcessor) sendPrivate(
ctx context.Context,
recipient *ecdsa.PublicKey,
rawMessage *RawMessage,
) ([]byte, error) {
p.logger.Debug("sending private message", zap.String("recipient", types.EncodeHex(crypto.FromECDSAPub(recipient))))
wrappedMessage, err := p.wrapMessageV1(rawMessage)
if err != nil {
return nil, errors.Wrap(err, "failed to wrap message")
}
messageID := v1protocol.MessageID(&rawMessage.Sender.PublicKey, wrappedMessage)
rawMessage.ID = types.EncodeHex(messageID)
// Notify before dispatching, otherwise the dispatch subscription might happen
// earlier than the scheduled
p.notifyOnScheduledMessage(rawMessage)
if p.featureFlags.Datasync && rawMessage.ResendAutomatically {
// No need to call transport tracking.
// It is done in a data sync dispatch step.
if err := p.addToDataSync(recipient, wrappedMessage); err != nil {
return nil, errors.Wrap(err, "failed to send message with datasync")
}
} else if rawMessage.SkipEncryption {
// When SkipEncryption is set we don't pass the message to the encryption layer
messageIDs := [][]byte{messageID}
hash, newMessage, err := p.sendPrivateRawMessage(ctx, recipient, wrappedMessage, messageIDs)
if err != nil {
return nil, errors.Wrap(err, "failed to send a message spec")
}
p.transport.Track(messageIDs, hash, newMessage)
} else {
messageSpec, err := p.protocol.BuildDirectMessage(rawMessage.Sender, recipient, wrappedMessage)
if err != nil {
return nil, errors.Wrap(err, "failed to encrypt message")
}
// The shared secret needs to be handle before we send a message
// otherwise the topic might not be set up before we receive a message
if p.handleSharedSecrets != nil {
err := p.handleSharedSecrets([]*sharedsecret.Secret{messageSpec.SharedSecret})
if err != nil {
return nil, err
}
}
messageIDs := [][]byte{messageID}
hash, newMessage, err := p.sendMessageSpec(ctx, recipient, messageSpec, messageIDs)
if err != nil {
return nil, errors.Wrap(err, "failed to send a message spec")
}
p.transport.Track(messageIDs, hash, newMessage)
}
return messageID, nil
}
// sendPairInstallation sends data to the recipients, using DH
func (p *MessageProcessor) SendPairInstallation(
ctx context.Context,
recipient *ecdsa.PublicKey,
rawMessage RawMessage,
) ([]byte, error) {
p.logger.Debug("sending private message", zap.String("recipient", types.EncodeHex(crypto.FromECDSAPub(recipient))))
wrappedMessage, err := p.wrapMessageV1(&rawMessage)
if err != nil {
return nil, errors.Wrap(err, "failed to wrap message")
}
messageSpec, err := p.protocol.BuildDHMessage(p.identity, recipient, wrappedMessage)
if err != nil {
return nil, errors.Wrap(err, "failed to encrypt message")
}
messageID := v1protocol.MessageID(&p.identity.PublicKey, wrappedMessage)
messageIDs := [][]byte{messageID}
hash, newMessage, err := p.sendMessageSpec(ctx, recipient, messageSpec, messageIDs)
if err != nil {
return nil, errors.Wrap(err, "failed to send a message spec")
}
p.transport.Track(messageIDs, hash, newMessage)
return messageID, nil
}
// EncodeMembershipUpdate takes a group and an optional chat message and returns the protobuf representation to be sent on the wire.
// All the events in a group are encoded and added to the payload
func (p *MessageProcessor) EncodeMembershipUpdate(
group *v1protocol.Group,
chatEntity ChatEntity,
) ([]byte, error) {
message := v1protocol.MembershipUpdateMessage{
ChatID: group.ChatID(),
Events: group.Events(),
}
if chatEntity != nil {
chatEntityProtobuf := chatEntity.GetProtobuf()
switch chatEntityProtobuf := chatEntityProtobuf.(type) {
case *protobuf.ChatMessage:
message.Message = chatEntityProtobuf
case *protobuf.EmojiReaction:
message.EmojiReaction = chatEntityProtobuf
}
}
encodedMessage, err := v1protocol.EncodeMembershipUpdateMessage(message)
if err != nil {
return nil, errors.Wrap(err, "failed to encode membership update message")
}
return encodedMessage, nil
}
// SendPublic takes encoded data, encrypts it and sends through the wire.
func (p *MessageProcessor) SendPublic(
ctx context.Context,
chatName string,
rawMessage RawMessage,
) ([]byte, error) {
// Set sender
if rawMessage.Sender == nil {
rawMessage.Sender = p.identity
}
wrappedMessage, err := p.wrapMessageV1(&rawMessage)
if err != nil {
return nil, errors.Wrap(err, "failed to wrap message")
}
var newMessage *types.NewMessage
messageSpec, err := p.protocol.BuildPublicMessage(p.identity, wrappedMessage)
if err != nil {
return nil, errors.Wrap(err, "failed to wrap a public message in the encryption layer")
}
if !rawMessage.SkipEncryption {
newMessage, err = MessageSpecToWhisper(messageSpec)
if err != nil {
return nil, err
}
} else {
newMessage = &types.NewMessage{
TTL: whisperTTL,
Payload: wrappedMessage,
PowTarget: calculatePoW(wrappedMessage),
PowTime: whisperPoWTime,
}
}
messageID := v1protocol.MessageID(&rawMessage.Sender.PublicKey, wrappedMessage)
rawMessage.ID = types.EncodeHex(messageID)
// notify before dispatching
p.notifyOnScheduledMessage(&rawMessage)
hash, err := p.transport.SendPublic(ctx, newMessage, chatName)
if err != nil {
return nil, err
}
sentMessage := &SentMessage{
Spec: messageSpec,
MessageIDs: [][]byte{messageID},
}
p.notifyOnSentMessage(sentMessage)
p.transport.Track([][]byte{messageID}, hash, newMessage)
return messageID, nil
}
// HandleMessages expects a whisper message as input, and it will go through
// a series of transformations until the message is parsed into an application
// layer message, or in case of Raw methods, the processing stops at the layer
// before.
// It returns an error only if the processing of required steps failed.
func (p *MessageProcessor) HandleMessages(shhMessage *types.Message, applicationLayer bool) ([]*v1protocol.StatusMessage, error) {
logger := p.logger.With(zap.String("site", "handleMessages"))
hlogger := logger.With(zap.ByteString("hash", shhMessage.Hash))
var statusMessage v1protocol.StatusMessage
err := statusMessage.HandleTransport(shhMessage)
if err != nil {
hlogger.Error("failed to handle transport layer message", zap.Error(err))
return nil, err
}
err = p.handleEncryptionLayer(context.Background(), &statusMessage)
if err != nil {
hlogger.Debug("failed to handle an encryption message", zap.Error(err))
}
statusMessages, err := statusMessage.HandleDatasync(p.datasync)
if err != nil {
hlogger.Debug("failed to handle datasync message", zap.Error(err))
}
for _, statusMessage := range statusMessages {
err := statusMessage.HandleApplicationMetadata()
if err != nil {
hlogger.Error("failed to handle application metadata layer message", zap.Error(err))
}
if applicationLayer {
err = statusMessage.HandleApplication()
if err != nil {
hlogger.Error("failed to handle application layer message", zap.Error(err))
}
}
}
return statusMessages, nil
}
// fetchDecryptionKey returns the private key associated with this public key, and returns true if it's an ephemeral key
func (p *MessageProcessor) fetchDecryptionKey(destination *ecdsa.PublicKey) (*ecdsa.PrivateKey, bool) {
destinationID := types.EncodeHex(crypto.FromECDSAPub(destination))
p.ephemeralKeysMutex.Lock()
decryptionKey, ok := p.ephemeralKeys[destinationID]
p.ephemeralKeysMutex.Unlock()
// the key is not there, fallback on identity
if !ok {
return p.identity, false
}
return decryptionKey, true
}
func (p *MessageProcessor) handleEncryptionLayer(ctx context.Context, message *v1protocol.StatusMessage) error {
logger := p.logger.With(zap.String("site", "handleEncryptionLayer"))
publicKey := message.SigPubKey()
// if it's an ephemeral key, we don't negotiate a topic
decryptionKey, skipNegotiation := p.fetchDecryptionKey(message.Dst)
err := message.HandleEncryption(decryptionKey, publicKey, p.protocol, skipNegotiation)
// if it's an ephemeral key, we don't have to handle a device not found error
if err == encryption.ErrDeviceNotFound && !skipNegotiation {
if err := p.handleErrDeviceNotFound(ctx, publicKey); err != nil {
logger.Error("failed to handle ErrDeviceNotFound", zap.Error(err))
}
}
if err != nil {
return errors.Wrap(err, "failed to process an encrypted message")
}
return nil
}
func (p *MessageProcessor) handleErrDeviceNotFound(ctx context.Context, publicKey *ecdsa.PublicKey) error {
now := time.Now().Unix()
advertise, err := p.protocol.ShouldAdvertiseBundle(publicKey, now)
if err != nil {
return err
}
if !advertise {
return nil
}
messageSpec, err := p.protocol.BuildBundleAdvertiseMessage(p.identity, publicKey)
if err != nil {
return err
}
ctx, cancel := context.WithTimeout(ctx, time.Second)
defer cancel()
// We don't pass an array of messageIDs as no action needs to be taken
// when sending a bundle
_, _, err = p.sendMessageSpec(ctx, publicKey, messageSpec, nil)
if err != nil {
return err
}
p.protocol.ConfirmBundleAdvertisement(publicKey, now)
return nil
}
func (p *MessageProcessor) wrapMessageV1(rawMessage *RawMessage) ([]byte, error) {
wrappedMessage, err := v1protocol.WrapMessageV1(rawMessage.Payload, rawMessage.MessageType, rawMessage.Sender)
if err != nil {
return nil, errors.Wrap(err, "failed to wrap message")
}
return wrappedMessage, nil
}
func (p *MessageProcessor) addToDataSync(publicKey *ecdsa.PublicKey, message []byte) error {
groupID := datasync.ToOneToOneGroupID(&p.identity.PublicKey, publicKey)
peerID := datasyncpeer.PublicKeyToPeerID(*publicKey)
exist, err := p.datasync.IsPeerInGroup(groupID, peerID)
if err != nil {
return errors.Wrap(err, "failed to check if peer is in group")
}
if !exist {
if err := p.datasync.AddPeer(groupID, peerID); err != nil {
return errors.Wrap(err, "failed to add peer")
}
}
_, err = p.datasync.AppendMessage(groupID, message)
if err != nil {
return errors.Wrap(err, "failed to append message to datasync")
}
return nil
}
// sendDataSync sends a message scheduled by the data sync layer.
// Data Sync layer calls this method "dispatch" function.
func (p *MessageProcessor) sendDataSync(ctx context.Context, publicKey *ecdsa.PublicKey, encodedMessage []byte, payload *datasyncproto.Payload) error {
// Calculate the messageIDs
messageIDs := make([][]byte, 0, len(payload.Messages))
for _, payload := range payload.Messages {
messageIDs = append(messageIDs, v1protocol.MessageID(&p.identity.PublicKey, payload.Body))
}
messageSpec, err := p.protocol.BuildDirectMessage(p.identity, publicKey, encodedMessage)
if err != nil {
return errors.Wrap(err, "failed to encrypt message")
}
// The shared secret needs to be handle before we send a message
// otherwise the topic might not be set up before we receive a message
if p.handleSharedSecrets != nil {
err := p.handleSharedSecrets([]*sharedsecret.Secret{messageSpec.SharedSecret})
if err != nil {
return err
}
}
hash, newMessage, err := p.sendMessageSpec(ctx, publicKey, messageSpec, messageIDs)
if err != nil {
return err
}
p.transport.Track(messageIDs, hash, newMessage)
return nil
}
// sendPrivateRawMessage sends a message not wrapped in an encryption layer
func (p *MessageProcessor) sendPrivateRawMessage(ctx context.Context, publicKey *ecdsa.PublicKey, payload []byte, messageIDs [][]byte) ([]byte, *types.NewMessage, error) {
newMessage := &types.NewMessage{
TTL: whisperTTL,
Payload: payload,
PowTarget: calculatePoW(payload),
PowTime: whisperPoWTime,
}
hash, err := p.transport.SendPrivateWithPartitioned(ctx, newMessage, publicKey)
if err != nil {
return nil, nil, err
}
return hash, newMessage, nil
}
// sendMessageSpec analyses the spec properties and selects a proper transport method.
func (p *MessageProcessor) sendMessageSpec(ctx context.Context, publicKey *ecdsa.PublicKey, messageSpec *encryption.ProtocolMessageSpec, messageIDs [][]byte) ([]byte, *types.NewMessage, error) {
newMessage, err := MessageSpecToWhisper(messageSpec)
if err != nil {
return nil, nil, err
}
logger := p.logger.With(zap.String("site", "sendMessageSpec"))
var hash []byte
// process shared secret
if messageSpec.AgreedSecret {
logger.Debug("sending using shared secret")
hash, err = p.transport.SendPrivateWithSharedSecret(ctx, newMessage, publicKey, messageSpec.SharedSecret.Key)
} else {
logger.Debug("sending partitioned topic")
hash, err = p.transport.SendPrivateWithPartitioned(ctx, newMessage, publicKey)
}
if err != nil {
return nil, nil, err
}
sentMessage := &SentMessage{
PublicKey: publicKey,
Spec: messageSpec,
MessageIDs: messageIDs,
}
p.notifyOnSentMessage(sentMessage)
return hash, newMessage, nil
}
// SubscribeToSentMessages returns a channel where we publish every time a message is sent
func (p *MessageProcessor) SubscribeToSentMessages() <-chan *SentMessage {
c := make(chan *SentMessage, 100)
p.sentMessagesSubscriptions = append(p.sentMessagesSubscriptions, c)
return c
}
func (p *MessageProcessor) notifyOnSentMessage(sentMessage *SentMessage) {
// Publish on channels, drop if buffer is full
for _, c := range p.sentMessagesSubscriptions {
select {
case c <- sentMessage:
default:
p.logger.Warn("sent messages subscription channel full, dropping message")
}
}
}
// SubscribeToScheduledMessages returns a channel where we publish every time a message is scheduled for sending
func (p *MessageProcessor) SubscribeToScheduledMessages() <-chan *RawMessage {
c := make(chan *RawMessage, 100)
p.scheduledMessagesSubscriptions = append(p.scheduledMessagesSubscriptions, c)
return c
}
func (p *MessageProcessor) notifyOnScheduledMessage(message *RawMessage) {
// Publish on channels, drop if buffer is full
for _, c := range p.scheduledMessagesSubscriptions {
select {
case c <- message:
default:
p.logger.Warn("scheduled messages subscription channel full, dropping message")
}
}
}
func (p *MessageProcessor) JoinPublic(chatID string) error {
return p.transport.JoinPublic(chatID)
}
// AddEphemeralKey adds an ephemeral key that we will be listening to
// note that we never removed them from now, as waku/whisper does not
// recalculate topics on removal, so effectively there's no benefit.
// On restart they will be gone.
func (p *MessageProcessor) AddEphemeralKey(privateKey *ecdsa.PrivateKey) (*transport.Filter, error) {
p.ephemeralKeysMutex.Lock()
p.ephemeralKeys[types.EncodeHex(crypto.FromECDSAPub(&privateKey.PublicKey))] = privateKey
p.ephemeralKeysMutex.Unlock()
return p.transport.LoadKeyFilters(privateKey)
}
func MessageSpecToWhisper(spec *encryption.ProtocolMessageSpec) (*types.NewMessage, error) {
var newMessage *types.NewMessage
payload, err := proto.Marshal(spec.Message)
if err != nil {
return newMessage, err
}
newMessage = &types.NewMessage{
TTL: whisperTTL,
Payload: payload,
PowTarget: calculatePoW(payload),
PowTime: whisperPoWTime,
}
return newMessage, nil
}
// calculatePoW returns the PoWTarget to be used.
// We check the size and arbitrarily set it to a lower PoW if the packet is
// greater than 50KB. We do this as the defaultPoW is too high for clients to send
// large messages.
func calculatePoW(payload []byte) float64 {
if len(payload) > largeSizeInBytes {
return whisperLargeSizePoW
}
return whisperDefaultPoW
}