matterbridge/vendor/go.mau.fi/whatsmeow/send.go

381 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 (
"crypto/rand"
"crypto/sha256"
"encoding/base64"
"encoding/hex"
"errors"
"fmt"
"sort"
"strings"
"time"
"go.mau.fi/libsignal/signalerror"
"google.golang.org/protobuf/proto"
"go.mau.fi/libsignal/groups"
"go.mau.fi/libsignal/keys/prekey"
"go.mau.fi/libsignal/protocol"
"go.mau.fi/libsignal/session"
waBinary "go.mau.fi/whatsmeow/binary"
waProto "go.mau.fi/whatsmeow/binary/proto"
"go.mau.fi/whatsmeow/types"
)
// GenerateMessageID generates a random string that can be used as a message ID on WhatsApp.
//
// msgID := whatsmeow.GenerateMessageID()
// cli.SendMessage(targetJID, msgID, &waProto.Message{...})
func GenerateMessageID() types.MessageID {
id := make([]byte, 16)
_, err := rand.Read(id)
if err != nil {
// Out of entropy
panic(err)
}
return strings.ToUpper(hex.EncodeToString(id))
}
// SendMessage sends the given message.
//
// If the message ID is not provided, a random message ID will be generated.
//
// This method will wait for the server to acknowledge the message before returning.
// The return value is the timestamp of the message from the server.
//
// The message itself can contain anything you want (within the protobuf schema).
// e.g. for a simple text message, use the Conversation field:
// cli.SendMessage(targetJID, "", &waProto.Message{
// Conversation: proto.String("Hello, World!"),
// })
//
// Things like replies, mentioning users and the "forwarded" flag are stored in ContextInfo,
// which can be put in ExtendedTextMessage and any of the media message types.
//
// For uploading and sending media/attachments, see the Upload method.
//
// For other message types, you'll have to figure it out yourself. Looking at the protobuf schema
// in binary/proto/def.proto may be useful to find out all the allowed fields.
func (cli *Client) SendMessage(to types.JID, id types.MessageID, message *waProto.Message) (time.Time, error) {
if to.AD {
return time.Time{}, ErrRecipientADJID
}
if len(id) == 0 {
id = GenerateMessageID()
}
cli.addRecentMessage(to, id, message)
respChan := cli.waitResponse(id)
var err error
var phash string
switch to.Server {
case types.GroupServer:
phash, err = cli.sendGroup(to, id, message)
case types.DefaultUserServer:
err = cli.sendDM(to, id, message)
case types.BroadcastServer:
err = ErrBroadcastListUnsupported
default:
err = fmt.Errorf("%w %s", ErrUnknownServer, to.Server)
}
if err != nil {
cli.cancelResponse(id, respChan)
return time.Time{}, err
}
resp := <-respChan
if resp == closedNode {
return time.Time{}, ErrSendDisconnected
}
ag := resp.AttrGetter()
ts := time.Unix(ag.Int64("t"), 0)
expectedPHash := ag.OptionalString("phash")
if len(expectedPHash) > 0 && phash != expectedPHash {
cli.Log.Warnf("Server returned different participant list hash when sending to %s. Some devices may not have received the message.", to)
// TODO also invalidate device list caches
cli.groupParticipantsCacheLock.Lock()
delete(cli.groupParticipantsCache, to)
cli.groupParticipantsCacheLock.Unlock()
}
return ts, nil
}
// RevokeMessage deletes the given message from everyone in the chat.
// You can only revoke your own messages, and if the message is too old, then other users will ignore the deletion.
//
// This method will wait for the server to acknowledge the revocation message before returning.
// The return value is the timestamp of the message from the server.
func (cli *Client) RevokeMessage(chat types.JID, id types.MessageID) (time.Time, error) {
return cli.SendMessage(chat, cli.generateRequestID(), &waProto.Message{
ProtocolMessage: &waProto.ProtocolMessage{
Type: waProto.ProtocolMessage_REVOKE.Enum(),
Key: &waProto.MessageKey{
FromMe: proto.Bool(true),
Id: proto.String(id),
RemoteJid: proto.String(chat.String()),
},
},
})
}
func participantListHashV2(participants []types.JID) string {
participantsStrings := make([]string, len(participants))
for i, part := range participants {
participantsStrings[i] = part.String()
}
sort.Strings(participantsStrings)
hash := sha256.Sum256([]byte(strings.Join(participantsStrings, "")))
return fmt.Sprintf("2:%s", base64.RawStdEncoding.EncodeToString(hash[:6]))
}
func (cli *Client) sendGroup(to types.JID, id types.MessageID, message *waProto.Message) (string, error) {
participants, err := cli.getGroupMembers(to)
if err != nil {
return "", fmt.Errorf("failed to get group members: %w", err)
}
plaintext, _, err := marshalMessage(to, message)
if err != nil {
return "", err
}
builder := groups.NewGroupSessionBuilder(cli.Store, pbSerializer)
senderKeyName := protocol.NewSenderKeyName(to.String(), cli.Store.ID.SignalAddress())
signalSKDMessage, err := builder.Create(senderKeyName)
if err != nil {
return "", fmt.Errorf("failed to create sender key distribution message to send %s to %s: %w", id, to, err)
}
skdMessage := &waProto.Message{
SenderKeyDistributionMessage: &waProto.SenderKeyDistributionMessage{
GroupId: proto.String(to.String()),
AxolotlSenderKeyDistributionMessage: signalSKDMessage.Serialize(),
},
}
skdPlaintext, err := proto.Marshal(skdMessage)
if err != nil {
return "", fmt.Errorf("failed to marshal sender key distribution message to send %s to %s: %w", id, to, err)
}
cipher := groups.NewGroupCipher(builder, senderKeyName, cli.Store)
encrypted, err := cipher.Encrypt(padMessage(plaintext))
if err != nil {
return "", fmt.Errorf("failed to encrypt group message to send %s to %s: %w", id, to, err)
}
ciphertext := encrypted.SignedSerialize()
node, allDevices, err := cli.prepareMessageNode(to, id, message, participants, skdPlaintext, nil)
if err != nil {
return "", err
}
phash := participantListHashV2(allDevices)
node.Attrs["phash"] = phash
node.Content = append(node.GetChildren(), waBinary.Node{
Tag: "enc",
Content: ciphertext,
Attrs: waBinary.Attrs{"v": "2", "type": "skmsg"},
})
err = cli.sendNode(*node)
if err != nil {
return "", fmt.Errorf("failed to send message node: %w", err)
}
return phash, nil
}
func (cli *Client) sendDM(to types.JID, id types.MessageID, message *waProto.Message) error {
messagePlaintext, deviceSentMessagePlaintext, err := marshalMessage(to, message)
if err != nil {
return err
}
node, _, err := cli.prepareMessageNode(to, id, message, []types.JID{to, *cli.Store.ID}, messagePlaintext, deviceSentMessagePlaintext)
if err != nil {
return err
}
err = cli.sendNode(*node)
if err != nil {
return fmt.Errorf("failed to send message node: %w", err)
}
return nil
}
func (cli *Client) prepareMessageNode(to types.JID, id types.MessageID, message *waProto.Message, participants []types.JID, plaintext, dsmPlaintext []byte) (*waBinary.Node, []types.JID, error) {
allDevices, err := cli.GetUserDevices(participants)
if err != nil {
return nil, nil, fmt.Errorf("failed to get device list: %w", err)
}
participantNodes, includeIdentity := cli.encryptMessageForDevices(allDevices, id, plaintext, dsmPlaintext)
node := waBinary.Node{
Tag: "message",
Attrs: waBinary.Attrs{
"id": id,
"type": "text",
"to": to,
},
Content: []waBinary.Node{{
Tag: "participants",
Content: participantNodes,
}},
}
if message.ProtocolMessage != nil && message.GetProtocolMessage().GetType() == waProto.ProtocolMessage_REVOKE && message.GetProtocolMessage().GetKey() != nil {
node.Attrs["edit"] = "7"
}
if includeIdentity {
err := cli.appendDeviceIdentityNode(&node)
if err != nil {
return nil, nil, err
}
}
return &node, allDevices, nil
}
func marshalMessage(to types.JID, message *waProto.Message) (plaintext, dsmPlaintext []byte, err error) {
plaintext, err = proto.Marshal(message)
if err != nil {
err = fmt.Errorf("failed to marshal message: %w", err)
return
}
if to.Server != types.GroupServer {
dsmPlaintext, err = proto.Marshal(&waProto.Message{
DeviceSentMessage: &waProto.DeviceSentMessage{
DestinationJid: proto.String(to.String()),
Message: message,
},
})
if err != nil {
err = fmt.Errorf("failed to marshal message (for own devices): %w", err)
return
}
}
return
}
func (cli *Client) appendDeviceIdentityNode(node *waBinary.Node) error {
deviceIdentity, err := proto.Marshal(cli.Store.Account)
if err != nil {
return fmt.Errorf("failed to marshal device identity: %w", err)
}
node.Content = append(node.GetChildren(), waBinary.Node{
Tag: "device-identity",
Content: deviceIdentity,
})
return nil
}
func (cli *Client) encryptMessageForDevices(allDevices []types.JID, id string, msgPlaintext, dsmPlaintext []byte) ([]waBinary.Node, bool) {
includeIdentity := false
participantNodes := make([]waBinary.Node, 0, len(allDevices))
var retryDevices []types.JID
for _, jid := range allDevices {
plaintext := msgPlaintext
if jid.User == cli.Store.ID.User && dsmPlaintext != nil {
if jid == *cli.Store.ID {
continue
}
plaintext = dsmPlaintext
}
encrypted, isPreKey, err := cli.encryptMessageForDeviceAndWrap(plaintext, jid, nil)
if errors.Is(err, ErrNoSession) {
retryDevices = append(retryDevices, jid)
continue
} else if err != nil {
cli.Log.Warnf("Failed to encrypt %s for %s: %v", id, jid, err)
continue
}
participantNodes = append(participantNodes, *encrypted)
if isPreKey {
includeIdentity = true
}
}
if len(retryDevices) > 0 {
bundles, err := cli.fetchPreKeys(retryDevices)
if err != nil {
cli.Log.Warnf("Failed to fetch prekeys for %d to retry encryption: %v", retryDevices, err)
} else {
for _, jid := range retryDevices {
resp := bundles[jid]
if resp.err != nil {
cli.Log.Warnf("Failed to fetch prekey for %s: %v", jid, resp.err)
continue
}
plaintext := msgPlaintext
if jid.User == cli.Store.ID.User && dsmPlaintext != nil {
plaintext = dsmPlaintext
}
encrypted, isPreKey, err := cli.encryptMessageForDeviceAndWrap(plaintext, jid, resp.bundle)
if err != nil {
cli.Log.Warnf("Failed to encrypt %s for %s (retry): %v", id, jid, err)
continue
}
participantNodes = append(participantNodes, *encrypted)
if isPreKey {
includeIdentity = true
}
}
}
}
return participantNodes, includeIdentity
}
func (cli *Client) encryptMessageForDeviceAndWrap(plaintext []byte, to types.JID, bundle *prekey.Bundle) (*waBinary.Node, bool, error) {
node, includeDeviceIdentity, err := cli.encryptMessageForDevice(plaintext, to, bundle)
if err != nil {
return nil, false, err
}
return &waBinary.Node{
Tag: "to",
Attrs: waBinary.Attrs{"jid": to},
Content: []waBinary.Node{*node},
}, includeDeviceIdentity, nil
}
func (cli *Client) encryptMessageForDevice(plaintext []byte, to types.JID, bundle *prekey.Bundle) (*waBinary.Node, bool, error) {
builder := session.NewBuilderFromSignal(cli.Store, to.SignalAddress(), pbSerializer)
if bundle != nil {
cli.Log.Debugf("Processing prekey bundle for %s", to)
err := builder.ProcessBundle(bundle)
if cli.AutoTrustIdentity && errors.Is(err, signalerror.ErrUntrustedIdentity) {
cli.Log.Warnf("Got %v error while trying to process prekey bundle for %s, clearing stored identity and retrying", err, to)
cli.clearUntrustedIdentity(to)
err = builder.ProcessBundle(bundle)
}
if err != nil {
return nil, false, fmt.Errorf("failed to process prekey bundle: %w", err)
}
} else if !cli.Store.ContainsSession(to.SignalAddress()) {
return nil, false, ErrNoSession
}
cipher := session.NewCipher(builder, to.SignalAddress())
ciphertext, err := cipher.Encrypt(padMessage(plaintext))
if err != nil {
return nil, false, fmt.Errorf("cipher encryption failed: %w", err)
}
encType := "msg"
if ciphertext.Type() == protocol.PREKEY_TYPE {
encType = "pkmsg"
}
return &waBinary.Node{
Tag: "enc",
Attrs: waBinary.Attrs{
"v": "2",
"type": encType,
},
Content: ciphertext.Serialize(),
}, encType == "pkmsg", nil
}