mirror of
https://github.com/42wim/matterbridge.git
synced 2024-12-24 20:22:39 +01:00
289 lines
9.8 KiB
Go
289 lines
9.8 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/hmac"
|
|
"crypto/sha256"
|
|
"encoding/base64"
|
|
"fmt"
|
|
"io"
|
|
"net/http"
|
|
|
|
"google.golang.org/protobuf/proto"
|
|
"google.golang.org/protobuf/reflect/protoreflect"
|
|
|
|
waProto "go.mau.fi/whatsmeow/binary/proto"
|
|
"go.mau.fi/whatsmeow/socket"
|
|
"go.mau.fi/whatsmeow/util/cbcutil"
|
|
"go.mau.fi/whatsmeow/util/hkdfutil"
|
|
)
|
|
|
|
// MediaType represents a type of uploaded file on WhatsApp.
|
|
// The value is the key which is used as a part of generating the encryption keys.
|
|
type MediaType string
|
|
|
|
// The known media types
|
|
const (
|
|
MediaImage MediaType = "WhatsApp Image Keys"
|
|
MediaVideo MediaType = "WhatsApp Video Keys"
|
|
MediaAudio MediaType = "WhatsApp Audio Keys"
|
|
MediaDocument MediaType = "WhatsApp Document Keys"
|
|
MediaHistory MediaType = "WhatsApp History Keys"
|
|
MediaAppState MediaType = "WhatsApp App State Keys"
|
|
|
|
MediaLinkThumbnail MediaType = "WhatsApp Link Thumbnail Keys"
|
|
)
|
|
|
|
// DownloadableMessage represents a protobuf message that contains attachment info.
|
|
//
|
|
// All of the downloadable messages inside a Message struct implement this interface
|
|
// (ImageMessage, VideoMessage, AudioMessage, DocumentMessage, StickerMessage).
|
|
type DownloadableMessage interface {
|
|
proto.Message
|
|
GetDirectPath() string
|
|
GetMediaKey() []byte
|
|
GetFileSha256() []byte
|
|
GetFileEncSha256() []byte
|
|
}
|
|
|
|
// DownloadableThumbnail represents a protobuf message that contains a thumbnail attachment.
|
|
//
|
|
// This is primarily meant for link preview thumbnails in ExtendedTextMessage.
|
|
type DownloadableThumbnail interface {
|
|
proto.Message
|
|
GetThumbnailDirectPath() string
|
|
GetThumbnailSha256() []byte
|
|
GetThumbnailEncSha256() []byte
|
|
GetMediaKey() []byte
|
|
}
|
|
|
|
// All the message types that are intended to be downloadable
|
|
var (
|
|
_ DownloadableMessage = (*waProto.ImageMessage)(nil)
|
|
_ DownloadableMessage = (*waProto.AudioMessage)(nil)
|
|
_ DownloadableMessage = (*waProto.VideoMessage)(nil)
|
|
_ DownloadableMessage = (*waProto.DocumentMessage)(nil)
|
|
_ DownloadableMessage = (*waProto.StickerMessage)(nil)
|
|
_ DownloadableMessage = (*waProto.HistorySyncNotification)(nil)
|
|
_ DownloadableMessage = (*waProto.ExternalBlobReference)(nil)
|
|
_ DownloadableThumbnail = (*waProto.ExtendedTextMessage)(nil)
|
|
)
|
|
|
|
type downloadableMessageWithLength interface {
|
|
DownloadableMessage
|
|
GetFileLength() uint64
|
|
}
|
|
|
|
type downloadableMessageWithSizeBytes interface {
|
|
DownloadableMessage
|
|
GetFileSizeBytes() uint64
|
|
}
|
|
|
|
type downloadableMessageWithURL interface {
|
|
DownloadableMessage
|
|
GetUrl() string
|
|
}
|
|
|
|
var classToMediaType = map[protoreflect.Name]MediaType{
|
|
"ImageMessage": MediaImage,
|
|
"AudioMessage": MediaAudio,
|
|
"VideoMessage": MediaVideo,
|
|
"DocumentMessage": MediaDocument,
|
|
"StickerMessage": MediaImage,
|
|
|
|
"HistorySyncNotification": MediaHistory,
|
|
"ExternalBlobReference": MediaAppState,
|
|
}
|
|
|
|
var classToThumbnailMediaType = map[protoreflect.Name]MediaType{
|
|
"ExtendedTextMessage": MediaLinkThumbnail,
|
|
}
|
|
|
|
var mediaTypeToMMSType = map[MediaType]string{
|
|
MediaImage: "image",
|
|
MediaAudio: "audio",
|
|
MediaVideo: "video",
|
|
MediaDocument: "document",
|
|
MediaHistory: "md-msg-hist",
|
|
MediaAppState: "md-app-state",
|
|
|
|
MediaLinkThumbnail: "thumbnail-link",
|
|
}
|
|
|
|
// DownloadAny loops through the downloadable parts of the given message and downloads the first non-nil item.
|
|
func (cli *Client) DownloadAny(msg *waProto.Message) (data []byte, err error) {
|
|
if msg == nil {
|
|
return nil, ErrNothingDownloadableFound
|
|
}
|
|
switch {
|
|
case msg.ImageMessage != nil:
|
|
return cli.Download(msg.ImageMessage)
|
|
case msg.VideoMessage != nil:
|
|
return cli.Download(msg.VideoMessage)
|
|
case msg.AudioMessage != nil:
|
|
return cli.Download(msg.AudioMessage)
|
|
case msg.DocumentMessage != nil:
|
|
return cli.Download(msg.DocumentMessage)
|
|
case msg.StickerMessage != nil:
|
|
return cli.Download(msg.StickerMessage)
|
|
default:
|
|
return nil, ErrNothingDownloadableFound
|
|
}
|
|
}
|
|
|
|
func getSize(msg DownloadableMessage) int {
|
|
switch sized := msg.(type) {
|
|
case downloadableMessageWithLength:
|
|
return int(sized.GetFileLength())
|
|
case downloadableMessageWithSizeBytes:
|
|
return int(sized.GetFileSizeBytes())
|
|
default:
|
|
return -1
|
|
}
|
|
}
|
|
|
|
// DownloadThumbnail downloads a thumbnail from a message.
|
|
//
|
|
// This is primarily intended for downloading link preview thumbnails, which are in ExtendedTextMessage:
|
|
// var msg *waProto.Message
|
|
// ...
|
|
// thumbnailImageBytes, err := cli.DownloadThumbnail(msg.GetExtendedTextMessage())
|
|
func (cli *Client) DownloadThumbnail(msg DownloadableThumbnail) ([]byte, error) {
|
|
mediaType, ok := classToThumbnailMediaType[msg.ProtoReflect().Descriptor().Name()]
|
|
if !ok {
|
|
return nil, fmt.Errorf("%w '%s'", ErrUnknownMediaType, string(msg.ProtoReflect().Descriptor().Name()))
|
|
} else if len(msg.GetThumbnailDirectPath()) > 0 {
|
|
return cli.DownloadMediaWithPath(msg.GetThumbnailDirectPath(), msg.GetThumbnailEncSha256(), msg.GetThumbnailSha256(), msg.GetMediaKey(), -1, mediaType, mediaTypeToMMSType[mediaType])
|
|
} else {
|
|
return nil, ErrNoURLPresent
|
|
}
|
|
}
|
|
|
|
// GetMediaType returns the MediaType value corresponding to the given protobuf message.
|
|
func GetMediaType(msg DownloadableMessage) MediaType {
|
|
return classToMediaType[msg.ProtoReflect().Descriptor().Name()]
|
|
}
|
|
|
|
// Download downloads the attachment from the given protobuf message.
|
|
//
|
|
// The attachment is a specific part of a Message protobuf struct, not the message itself, e.g.
|
|
// var msg *waProto.Message
|
|
// ...
|
|
// imageData, err := cli.Download(msg.GetImageMessage())
|
|
//
|
|
// You can also use DownloadAny to download the first non-nil sub-message.
|
|
func (cli *Client) Download(msg DownloadableMessage) ([]byte, error) {
|
|
mediaType, ok := classToMediaType[msg.ProtoReflect().Descriptor().Name()]
|
|
if !ok {
|
|
return nil, fmt.Errorf("%w '%s'", ErrUnknownMediaType, string(msg.ProtoReflect().Descriptor().Name()))
|
|
}
|
|
urlable, ok := msg.(downloadableMessageWithURL)
|
|
if ok && len(urlable.GetUrl()) > 0 {
|
|
return cli.downloadAndDecrypt(urlable.GetUrl(), msg.GetMediaKey(), mediaType, getSize(msg), msg.GetFileEncSha256(), msg.GetFileSha256())
|
|
} else if len(msg.GetDirectPath()) > 0 {
|
|
return cli.DownloadMediaWithPath(msg.GetDirectPath(), msg.GetFileEncSha256(), msg.GetFileSha256(), msg.GetMediaKey(), getSize(msg), mediaType, mediaTypeToMMSType[mediaType])
|
|
} else {
|
|
return nil, ErrNoURLPresent
|
|
}
|
|
}
|
|
|
|
// DownloadMediaWithPath downloads an attachment by manually specifying the path and encryption details.
|
|
func (cli *Client) DownloadMediaWithPath(directPath string, encFileHash, fileHash, mediaKey []byte, fileLength int, mediaType MediaType, mmsType string) (data []byte, err error) {
|
|
err = cli.refreshMediaConn(false)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("failed to refresh media connections: %w", err)
|
|
}
|
|
if len(mmsType) == 0 {
|
|
mmsType = mediaTypeToMMSType[mediaType]
|
|
}
|
|
for i, host := range cli.mediaConn.Hosts {
|
|
mediaURL := fmt.Sprintf("https://%s%s&hash=%s&mms-type=%s&__wa-mms=", host.Hostname, directPath, base64.URLEncoding.EncodeToString(encFileHash), mmsType)
|
|
data, err = cli.downloadAndDecrypt(mediaURL, mediaKey, mediaType, fileLength, encFileHash, fileHash)
|
|
// TODO there are probably some errors that shouldn't retry
|
|
if err != nil {
|
|
if i >= len(cli.mediaConn.Hosts)-1 {
|
|
return nil, fmt.Errorf("failed to download media from last host: %w", err)
|
|
}
|
|
cli.Log.Warnf("Failed to download media: %s, trying with next host...", err)
|
|
}
|
|
}
|
|
return
|
|
}
|
|
|
|
func (cli *Client) downloadAndDecrypt(url string, mediaKey []byte, appInfo MediaType, fileLength int, fileEncSha256, fileSha256 []byte) (data []byte, err error) {
|
|
iv, cipherKey, macKey, _ := getMediaKeys(mediaKey, appInfo)
|
|
var ciphertext, mac []byte
|
|
if ciphertext, mac, err = cli.downloadEncryptedMedia(url, fileEncSha256); err != nil {
|
|
|
|
} else if err = validateMedia(iv, ciphertext, macKey, mac); err != nil {
|
|
|
|
} else if data, err = cbcutil.Decrypt(cipherKey, iv, ciphertext); err != nil {
|
|
err = fmt.Errorf("failed to decrypt file: %w", err)
|
|
} else if fileLength >= 0 && len(data) != fileLength {
|
|
err = fmt.Errorf("%w: expected %d, got %d", ErrFileLengthMismatch, fileLength, len(data))
|
|
} else if len(fileSha256) == 32 && sha256.Sum256(data) != *(*[32]byte)(fileSha256) {
|
|
err = ErrInvalidMediaSHA256
|
|
}
|
|
return
|
|
}
|
|
|
|
func getMediaKeys(mediaKey []byte, appInfo MediaType) (iv, cipherKey, macKey, refKey []byte) {
|
|
mediaKeyExpanded := hkdfutil.SHA256(mediaKey, nil, []byte(appInfo), 112)
|
|
return mediaKeyExpanded[:16], mediaKeyExpanded[16:48], mediaKeyExpanded[48:80], mediaKeyExpanded[80:]
|
|
}
|
|
|
|
func (cli *Client) downloadEncryptedMedia(url string, checksum []byte) (file, mac []byte, err error) {
|
|
var req *http.Request
|
|
req, err = http.NewRequest(http.MethodGet, url, nil)
|
|
if err != nil {
|
|
err = fmt.Errorf("failed to prepare request: %w", err)
|
|
return
|
|
}
|
|
req.Header.Set("Origin", socket.Origin)
|
|
req.Header.Set("Referer", socket.Origin+"/")
|
|
var resp *http.Response
|
|
resp, err = cli.http.Do(req)
|
|
if err != nil {
|
|
return
|
|
}
|
|
defer resp.Body.Close()
|
|
if resp.StatusCode != http.StatusOK {
|
|
if resp.StatusCode == http.StatusNotFound {
|
|
err = ErrMediaDownloadFailedWith404
|
|
} else if resp.StatusCode == http.StatusGone {
|
|
err = ErrMediaDownloadFailedWith410
|
|
} else {
|
|
err = fmt.Errorf("download failed with status code %d", resp.StatusCode)
|
|
}
|
|
return
|
|
}
|
|
var data []byte
|
|
data, err = io.ReadAll(resp.Body)
|
|
if err != nil {
|
|
return
|
|
} else if len(data) <= 10 {
|
|
err = ErrTooShortFile
|
|
return
|
|
}
|
|
file, mac = data[:len(data)-10], data[len(data)-10:]
|
|
if len(checksum) == 32 && sha256.Sum256(data) != *(*[32]byte)(checksum) {
|
|
err = ErrInvalidMediaEncSHA256
|
|
}
|
|
return
|
|
}
|
|
|
|
func validateMedia(iv, file, macKey, mac []byte) error {
|
|
h := hmac.New(sha256.New, macKey)
|
|
h.Write(iv)
|
|
h.Write(file)
|
|
if !hmac.Equal(h.Sum(nil)[:10], mac) {
|
|
return ErrInvalidMediaHMAC
|
|
}
|
|
return nil
|
|
}
|