384 lines
12 KiB
Go
384 lines
12 KiB
Go
// Copyright (c) 2021 Tulir Asokan
|
|
//
|
|
// This Source Code Form is subject to the terms of the Mozilla Public
|
|
// License, v. 2.0. If a copy of the MPL was not distributed with this
|
|
// file, You can obtain one at http://mozilla.org/MPL/2.0/.
|
|
|
|
package whatsmeow
|
|
|
|
import (
|
|
"bytes"
|
|
"compress/zlib"
|
|
"crypto/rand"
|
|
"errors"
|
|
"fmt"
|
|
"io"
|
|
"strconv"
|
|
"time"
|
|
|
|
"go.mau.fi/libsignal/signalerror"
|
|
"google.golang.org/protobuf/proto"
|
|
|
|
"go.mau.fi/libsignal/groups"
|
|
"go.mau.fi/libsignal/protocol"
|
|
"go.mau.fi/libsignal/session"
|
|
|
|
"go.mau.fi/whatsmeow/appstate"
|
|
waBinary "go.mau.fi/whatsmeow/binary"
|
|
waProto "go.mau.fi/whatsmeow/binary/proto"
|
|
"go.mau.fi/whatsmeow/store"
|
|
"go.mau.fi/whatsmeow/types"
|
|
"go.mau.fi/whatsmeow/types/events"
|
|
)
|
|
|
|
var pbSerializer = store.SignalProtobufSerializer
|
|
|
|
func (cli *Client) handleEncryptedMessage(node *waBinary.Node) {
|
|
info, err := cli.parseMessageInfo(node)
|
|
if err != nil {
|
|
cli.Log.Warnf("Failed to parse message: %v", err)
|
|
} else {
|
|
if len(info.PushName) > 0 && info.PushName != "-" {
|
|
go cli.updatePushName(info.Sender, info, info.PushName)
|
|
}
|
|
cli.decryptMessages(info, node)
|
|
}
|
|
}
|
|
|
|
func (cli *Client) parseMessageSource(node *waBinary.Node) (source types.MessageSource, err error) {
|
|
from, ok := node.Attrs["from"].(types.JID)
|
|
if !ok {
|
|
err = fmt.Errorf("didn't find valid `from` attribute in message")
|
|
} else if from.Server == types.GroupServer || from.Server == types.BroadcastServer {
|
|
source.IsGroup = true
|
|
source.Chat = from
|
|
sender, ok := node.Attrs["participant"].(types.JID)
|
|
if !ok {
|
|
err = fmt.Errorf("didn't find valid `participant` attribute in group message")
|
|
} else {
|
|
source.Sender = sender
|
|
if source.Sender.User == cli.Store.ID.User {
|
|
source.IsFromMe = true
|
|
}
|
|
}
|
|
if from.Server == types.BroadcastServer {
|
|
recipient, ok := node.Attrs["recipient"].(types.JID)
|
|
if ok {
|
|
source.BroadcastListOwner = recipient
|
|
}
|
|
}
|
|
} else if from.User == cli.Store.ID.User {
|
|
source.IsFromMe = true
|
|
source.Sender = from
|
|
recipient, ok := node.Attrs["recipient"].(types.JID)
|
|
if !ok {
|
|
source.Chat = from.ToNonAD()
|
|
} else {
|
|
source.Chat = recipient
|
|
}
|
|
} else {
|
|
source.Chat = from.ToNonAD()
|
|
source.Sender = from
|
|
}
|
|
return
|
|
}
|
|
|
|
func (cli *Client) parseMessageInfo(node *waBinary.Node) (*types.MessageInfo, error) {
|
|
var info types.MessageInfo
|
|
var err error
|
|
var ok bool
|
|
info.MessageSource, err = cli.parseMessageSource(node)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
info.ID, ok = node.Attrs["id"].(string)
|
|
if !ok {
|
|
return nil, fmt.Errorf("didn't find valid `id` attribute in message")
|
|
}
|
|
ts, ok := node.Attrs["t"].(string)
|
|
if !ok {
|
|
return nil, fmt.Errorf("didn't find valid `t` (timestamp) attribute in message")
|
|
}
|
|
tsInt, err := strconv.ParseInt(ts, 10, 64)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("didn't find valid `t` (timestamp) attribute in message: %w", err)
|
|
}
|
|
info.Timestamp = time.Unix(tsInt, 0)
|
|
|
|
info.PushName, _ = node.Attrs["notify"].(string)
|
|
info.Category, _ = node.Attrs["category"].(string)
|
|
|
|
return &info, nil
|
|
}
|
|
|
|
func (cli *Client) decryptMessages(info *types.MessageInfo, node *waBinary.Node) {
|
|
go cli.sendAck(node)
|
|
if len(node.GetChildrenByTag("unavailable")) == len(node.GetChildren()) {
|
|
cli.Log.Warnf("Unavailable message %s from %s", info.ID, info.SourceString())
|
|
go cli.sendRetryReceipt(node, true)
|
|
cli.dispatchEvent(&events.UndecryptableMessage{Info: *info, IsUnavailable: true})
|
|
return
|
|
}
|
|
children := node.GetChildren()
|
|
cli.Log.Debugf("Decrypting %d messages from %s", len(children), info.SourceString())
|
|
handled := false
|
|
for _, child := range children {
|
|
if child.Tag != "enc" {
|
|
continue
|
|
}
|
|
encType, ok := child.Attrs["type"].(string)
|
|
if !ok {
|
|
continue
|
|
}
|
|
var decrypted []byte
|
|
var err error
|
|
if encType == "pkmsg" || encType == "msg" {
|
|
decrypted, err = cli.decryptDM(&child, info.Sender, encType == "pkmsg")
|
|
} else if info.IsGroup && encType == "skmsg" {
|
|
decrypted, err = cli.decryptGroupMsg(&child, info.Sender, info.Chat)
|
|
} else {
|
|
cli.Log.Warnf("Unhandled encrypted message (type %s) from %s", encType, info.SourceString())
|
|
continue
|
|
}
|
|
if err != nil {
|
|
cli.Log.Warnf("Error decrypting message from %s: %v", info.SourceString(), err)
|
|
go cli.sendRetryReceipt(node, false)
|
|
cli.dispatchEvent(&events.UndecryptableMessage{Info: *info, IsUnavailable: false})
|
|
return
|
|
}
|
|
|
|
var msg waProto.Message
|
|
err = proto.Unmarshal(decrypted, &msg)
|
|
if err != nil {
|
|
cli.Log.Warnf("Error unmarshaling decrypted message from %s: %v", info.SourceString(), err)
|
|
continue
|
|
}
|
|
|
|
cli.handleDecryptedMessage(info, &msg)
|
|
handled = true
|
|
}
|
|
if handled {
|
|
go cli.sendMessageReceipt(info)
|
|
}
|
|
}
|
|
|
|
func (cli *Client) decryptDM(child *waBinary.Node, from types.JID, isPreKey bool) ([]byte, error) {
|
|
content, _ := child.Content.([]byte)
|
|
|
|
builder := session.NewBuilderFromSignal(cli.Store, from.SignalAddress(), pbSerializer)
|
|
cipher := session.NewCipher(builder, from.SignalAddress())
|
|
var plaintext []byte
|
|
if isPreKey {
|
|
preKeyMsg, err := protocol.NewPreKeySignalMessageFromBytes(content, pbSerializer.PreKeySignalMessage, pbSerializer.SignalMessage)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to parse prekey message: %w", err)
|
|
}
|
|
plaintext, _, err = cipher.DecryptMessageReturnKey(preKeyMsg)
|
|
if errors.Is(err, signalerror.ErrUntrustedIdentity) {
|
|
cli.Log.Warnf("Got %v error while trying to decrypt prekey message from %s, clearing stored identity and retrying", err, from)
|
|
err = cli.Store.Identities.DeleteIdentity(from.SignalAddress().String())
|
|
if err != nil {
|
|
cli.Log.Warnf("Failed to delete identity of %s from store after decryption error: %v", from, err)
|
|
}
|
|
err = cli.Store.Sessions.DeleteSession(from.SignalAddress().String())
|
|
if err != nil {
|
|
cli.Log.Warnf("Failed to delete session with %s from store after decryption error: %v", from, err)
|
|
}
|
|
cli.dispatchEvent(&events.IdentityChange{JID: from, Timestamp: time.Now(), Implicit: true})
|
|
plaintext, _, err = cipher.DecryptMessageReturnKey(preKeyMsg)
|
|
}
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to decrypt prekey message: %w", err)
|
|
}
|
|
} else {
|
|
msg, err := protocol.NewSignalMessageFromBytes(content, pbSerializer.SignalMessage)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to parse normal message: %w", err)
|
|
}
|
|
plaintext, err = cipher.Decrypt(msg)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to decrypt normal message: %w", err)
|
|
}
|
|
}
|
|
return unpadMessage(plaintext)
|
|
}
|
|
|
|
func (cli *Client) decryptGroupMsg(child *waBinary.Node, from types.JID, chat types.JID) ([]byte, error) {
|
|
content, _ := child.Content.([]byte)
|
|
|
|
senderKeyName := protocol.NewSenderKeyName(chat.String(), from.SignalAddress())
|
|
builder := groups.NewGroupSessionBuilder(cli.Store, pbSerializer)
|
|
cipher := groups.NewGroupCipher(builder, senderKeyName, cli.Store)
|
|
msg, err := protocol.NewSenderKeyMessageFromBytes(content, pbSerializer.SenderKeyMessage)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to parse group message: %w", err)
|
|
}
|
|
plaintext, err := cipher.Decrypt(msg)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to decrypt group message: %w", err)
|
|
}
|
|
return unpadMessage(plaintext)
|
|
}
|
|
|
|
const checkPadding = true
|
|
|
|
func isValidPadding(plaintext []byte) bool {
|
|
lastByte := plaintext[len(plaintext)-1]
|
|
expectedPadding := bytes.Repeat([]byte{lastByte}, int(lastByte))
|
|
return bytes.HasSuffix(plaintext, expectedPadding)
|
|
}
|
|
|
|
func unpadMessage(plaintext []byte) ([]byte, error) {
|
|
if checkPadding && !isValidPadding(plaintext) {
|
|
return nil, fmt.Errorf("plaintext doesn't have expected padding")
|
|
}
|
|
return plaintext[:len(plaintext)-int(plaintext[len(plaintext)-1])], nil
|
|
}
|
|
|
|
func padMessage(plaintext []byte) []byte {
|
|
var pad [1]byte
|
|
_, err := rand.Read(pad[:])
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
pad[0] &= 0xf
|
|
if pad[0] == 0 {
|
|
pad[0] = 0xf
|
|
}
|
|
plaintext = append(plaintext, bytes.Repeat(pad[:], int(pad[0]))...)
|
|
return plaintext
|
|
}
|
|
|
|
func (cli *Client) handleSenderKeyDistributionMessage(chat, from types.JID, rawSKDMsg *waProto.SenderKeyDistributionMessage) {
|
|
builder := groups.NewGroupSessionBuilder(cli.Store, pbSerializer)
|
|
senderKeyName := protocol.NewSenderKeyName(chat.String(), from.SignalAddress())
|
|
sdkMsg, err := protocol.NewSenderKeyDistributionMessageFromBytes(rawSKDMsg.AxolotlSenderKeyDistributionMessage, pbSerializer.SenderKeyDistributionMessage)
|
|
if err != nil {
|
|
cli.Log.Errorf("Failed to parse sender key distribution message from %s for %s: %v", from, chat, err)
|
|
return
|
|
}
|
|
builder.Process(senderKeyName, sdkMsg)
|
|
cli.Log.Debugf("Processed sender key distribution message from %s in %s", senderKeyName.Sender().String(), senderKeyName.GroupID())
|
|
}
|
|
|
|
func (cli *Client) handleHistorySyncNotification(notif *waProto.HistorySyncNotification) {
|
|
var historySync waProto.HistorySync
|
|
if data, err := cli.Download(notif); err != nil {
|
|
cli.Log.Errorf("Failed to download history sync data: %v", err)
|
|
} else if reader, err := zlib.NewReader(bytes.NewReader(data)); err != nil {
|
|
cli.Log.Errorf("Failed to create zlib reader for history sync data: %v", err)
|
|
} else if rawData, err := io.ReadAll(reader); err != nil {
|
|
cli.Log.Errorf("Failed to decompress history sync data: %v", err)
|
|
} else if err = proto.Unmarshal(rawData, &historySync); err != nil {
|
|
cli.Log.Errorf("Failed to unmarshal history sync data: %v", err)
|
|
} else {
|
|
cli.Log.Debugf("Received history sync")
|
|
if historySync.GetSyncType() == waProto.HistorySync_PUSH_NAME {
|
|
go cli.handleHistoricalPushNames(historySync.GetPushnames())
|
|
}
|
|
cli.dispatchEvent(&events.HistorySync{
|
|
Data: &historySync,
|
|
})
|
|
}
|
|
}
|
|
|
|
func (cli *Client) handleAppStateSyncKeyShare(keys *waProto.AppStateSyncKeyShare) {
|
|
for _, key := range keys.GetKeys() {
|
|
marshaledFingerprint, err := proto.Marshal(key.GetKeyData().GetFingerprint())
|
|
if err != nil {
|
|
cli.Log.Errorf("Failed to marshal fingerprint of app state sync key %X", key.GetKeyId().GetKeyId())
|
|
continue
|
|
}
|
|
err = cli.Store.AppStateKeys.PutAppStateSyncKey(key.GetKeyId().GetKeyId(), store.AppStateSyncKey{
|
|
Data: key.GetKeyData().GetKeyData(),
|
|
Fingerprint: marshaledFingerprint,
|
|
Timestamp: key.GetKeyData().GetTimestamp(),
|
|
})
|
|
if err != nil {
|
|
cli.Log.Errorf("Failed to store app state sync key %X", key.GetKeyId().GetKeyId())
|
|
continue
|
|
}
|
|
cli.Log.Debugf("Received app state sync key %X", key.GetKeyId().GetKeyId())
|
|
}
|
|
|
|
for _, name := range appstate.AllPatchNames {
|
|
err := cli.FetchAppState(name, false, true)
|
|
if err != nil {
|
|
cli.Log.Errorf("Failed to do initial fetch of app state %s: %v", name, err)
|
|
}
|
|
}
|
|
}
|
|
|
|
func (cli *Client) handleProtocolMessage(info *types.MessageInfo, msg *waProto.Message) {
|
|
protoMsg := msg.GetProtocolMessage()
|
|
|
|
if protoMsg.GetHistorySyncNotification() != nil && info.IsFromMe {
|
|
cli.handleHistorySyncNotification(protoMsg.HistorySyncNotification)
|
|
cli.sendProtocolMessageReceipt(info.ID, "hist_sync")
|
|
}
|
|
|
|
if protoMsg.GetAppStateSyncKeyShare() != nil && info.IsFromMe {
|
|
cli.handleAppStateSyncKeyShare(protoMsg.AppStateSyncKeyShare)
|
|
}
|
|
|
|
if info.Category == "peer" {
|
|
cli.sendProtocolMessageReceipt(info.ID, "peer_msg")
|
|
}
|
|
}
|
|
|
|
func (cli *Client) handleDecryptedMessage(info *types.MessageInfo, msg *waProto.Message) {
|
|
evt := &events.Message{Info: *info, RawMessage: msg}
|
|
|
|
// First unwrap device sent messages
|
|
if msg.GetDeviceSentMessage().GetMessage() != nil {
|
|
msg = msg.GetDeviceSentMessage().GetMessage()
|
|
evt.Info.DeviceSentMeta = &types.DeviceSentMeta{
|
|
DestinationJID: msg.GetDeviceSentMessage().GetDestinationJid(),
|
|
Phash: msg.GetDeviceSentMessage().GetPhash(),
|
|
}
|
|
}
|
|
|
|
if msg.GetSenderKeyDistributionMessage() != nil {
|
|
if !info.IsGroup {
|
|
cli.Log.Warnf("Got sender key distribution message in non-group chat from", info.Sender)
|
|
} else {
|
|
cli.handleSenderKeyDistributionMessage(info.Chat, info.Sender, msg.SenderKeyDistributionMessage)
|
|
}
|
|
}
|
|
if msg.GetProtocolMessage() != nil {
|
|
go cli.handleProtocolMessage(info, msg)
|
|
}
|
|
|
|
// Unwrap ephemeral and view-once messages
|
|
// Hopefully sender key distribution messages and protocol messages can't be inside ephemeral messages
|
|
if msg.GetEphemeralMessage().GetMessage() != nil {
|
|
msg = msg.GetEphemeralMessage().GetMessage()
|
|
evt.IsEphemeral = true
|
|
}
|
|
if msg.GetViewOnceMessage().GetMessage() != nil {
|
|
msg = msg.GetViewOnceMessage().GetMessage()
|
|
evt.IsViewOnce = true
|
|
}
|
|
evt.Message = msg
|
|
|
|
cli.dispatchEvent(evt)
|
|
}
|
|
|
|
func (cli *Client) sendProtocolMessageReceipt(id, msgType string) {
|
|
if len(id) == 0 {
|
|
return
|
|
}
|
|
err := cli.sendNode(waBinary.Node{
|
|
Tag: "receipt",
|
|
Attrs: waBinary.Attrs{
|
|
"id": id,
|
|
"type": msgType,
|
|
"to": types.NewJID(cli.Store.ID.User, types.LegacyUserServer),
|
|
},
|
|
Content: nil,
|
|
})
|
|
if err != nil {
|
|
cli.Log.Warnf("Failed to send acknowledgement for protocol message %s: %v", id, err)
|
|
}
|
|
}
|