1 files changed, 199 insertions, 0 deletions
diff --git a/vendor/github.com/matterbridge/go-whatsapp/media.go b/vendor/github.com/matterbridge/go-whatsapp/media.go
new file mode 100644
index 00000000..9fcc08e2
--- /dev/null
+++ b/vendor/github.com/matterbridge/go-whatsapp/media.go
@@ -0,0 +1,199 @@
+package whatsapp
+
+import (
+	"bytes"
+	"crypto/hmac"
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"github.com/matterbridge/go-whatsapp/crypto/cbc"
+	"github.com/matterbridge/go-whatsapp/crypto/hkdf"
+	"io"
+	"io/ioutil"
+	"mime/multipart"
+	"net/http"
+	"os"
+	"strings"
+	"time"
+)
+
+func Download(url string, mediaKey []byte, appInfo MediaType, fileLength int) ([]byte, error) {
+	if url == "" {
+		return nil, fmt.Errorf("no url present")
+	}
+	file, mac, err := downloadMedia(url)
+	if err != nil {
+		return nil, err
+	}
+	iv, cipherKey, macKey, _, err := getMediaKeys(mediaKey, appInfo)
+	if err != nil {
+		return nil, err
+	}
+	if err = validateMedia(iv, file, macKey, mac); err != nil {
+		return nil, err
+	}
+	data, err := cbc.Decrypt(cipherKey, iv, file)
+	if err != nil {
+		return nil, err
+	}
+	if len(data) != fileLength {
+		return nil, fmt.Errorf("file length does not match")
+	}
+	return data, nil
+}
+
+func validateMedia(iv []byte, file []byte, macKey []byte, mac []byte) error {
+	h := hmac.New(sha256.New, macKey)
+	n, err := h.Write(append(iv, file...))
+	if err != nil {
+		return err
+	}
+	if n < 10 {
+		return fmt.Errorf("hash to short")
+	}
+	if !hmac.Equal(h.Sum(nil)[:10], mac) {
+		return fmt.Errorf("invalid media hmac")
+	}
+	return nil
+}
+
+func getMediaKeys(mediaKey []byte, appInfo MediaType) (iv, cipherKey, macKey, refKey []byte, err error) {
+	mediaKeyExpanded, err := hkdf.Expand(mediaKey, 112, string(appInfo))
+	if err != nil {
+		return nil, nil, nil, nil, err
+	}
+	return mediaKeyExpanded[:16], mediaKeyExpanded[16:48], mediaKeyExpanded[48:80], mediaKeyExpanded[80:], nil
+}
+
+func downloadMedia(url string) (file []byte, mac []byte, err error) {
+	resp, err := http.Get(url)
+	if err != nil {
+		return nil, nil, err
+	}
+	if resp.StatusCode != 200 {
+		return nil, nil, fmt.Errorf("download failed")
+	}
+	defer resp.Body.Close()
+	if resp.ContentLength <= 10 {
+		return nil, nil, fmt.Errorf("file to short")
+	}
+	data, err := ioutil.ReadAll(resp.Body)
+	n := len(data)
+	if err != nil {
+		return nil, nil, err
+	}
+	return data[:n-10], data[n-10 : n], nil
+}
+
+func (wac *Conn) Upload(reader io.Reader, appInfo MediaType) (url string, mediaKey []byte, fileEncSha256 []byte, fileSha256 []byte, fileLength uint64, err error) {
+	data, err := ioutil.ReadAll(reader)
+	if err != nil {
+		return "", nil, nil, nil, 0, err
+	}
+
+	mediaKey = make([]byte, 32)
+	rand.Read(mediaKey)
+
+	iv, cipherKey, macKey, _, err := getMediaKeys(mediaKey, appInfo)
+	if err != nil {
+		return "", nil, nil, nil, 0, err
+	}
+
+	enc, err := cbc.Encrypt(cipherKey, iv, data)
+	if err != nil {
+		return "", nil, nil, nil, 0, err
+	}
+
+	fileLength = uint64(len(data))
+
+	h := hmac.New(sha256.New, macKey)
+	h.Write(append(iv, enc...))
+	mac := h.Sum(nil)[:10]
+
+	sha := sha256.New()
+	sha.Write(data)
+	fileSha256 = sha.Sum(nil)
+
+	sha.Reset()
+	sha.Write(append(enc, mac...))
+	fileEncSha256 = sha.Sum(nil)
+
+	var filetype string
+	switch appInfo {
+	case MediaImage:
+		filetype = "image"
+	case MediaAudio:
+		filetype = "audio"
+	case MediaDocument:
+		filetype = "document"
+	case MediaVideo:
+		filetype = "video"
+	}
+
+	uploadReq := []interface{}{"action", "encr_upload", filetype, base64.StdEncoding.EncodeToString(fileEncSha256)}
+	ch, err := wac.write(uploadReq)
+	if err != nil {
+		return "", nil, nil, nil, 0, err
+	}
+
+	var resp map[string]interface{}
+	select {
+	case r := <-ch:
+		if err = json.Unmarshal([]byte(r), &resp); err != nil {
+			return "", nil, nil, nil, 0, fmt.Errorf("error decoding upload response: %v\n", err)
+		}
+	case <-time.After(wac.msgTimeout):
+		return "", nil, nil, nil, 0, fmt.Errorf("restore session init timed out")
+	}
+
+	if int(resp["status"].(float64)) != 200 {
+		return "", nil, nil, nil, 0, fmt.Errorf("upload responsed with %d", resp["status"])
+	}
+
+	var b bytes.Buffer
+	w := multipart.NewWriter(&b)
+	hashWriter, err := w.CreateFormField("hash")
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "%v\n", err)
+	}
+	io.Copy(hashWriter, strings.NewReader(base64.StdEncoding.EncodeToString(fileEncSha256)))
+
+	fileWriter, err := w.CreateFormFile("file", "blob")
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "%v\n", err)
+	}
+	io.Copy(fileWriter, bytes.NewReader(append(enc, mac...)))
+	err = w.Close()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "%v\n", err)
+	}
+
+	req, err := http.NewRequest("POST", resp["url"].(string), &b)
+	if err != nil {
+		return "", nil, nil, nil, 0, err
+	}
+
+	req.Header.Set("Content-Type", w.FormDataContentType())
+	req.Header.Set("Origin", "https://web.whatsapp.com")
+	req.Header.Set("Referer", "https://web.whatsapp.com/")
+
+	req.URL.Query().Set("f", "j")
+
+	client := &http.Client{}
+	// Submit the request
+	res, err := client.Do(req)
+	if err != nil {
+		return "", nil, nil, nil, 0, err
+	}
+
+	if res.StatusCode != http.StatusOK {
+		return "", nil, nil, nil, 0, fmt.Errorf("upload failed with status code %d", res.StatusCode)
+	}
+
+	var jsonRes map[string]string
+	json.NewDecoder(res.Body).Decode(&jsonRes)
+
+	return jsonRes["url"], mediaKey, fileEncSha256, fileSha256, fileLength, nil
+}