aes-decrypt emoji from encrypturl

README.md

@@ -18,7 +18,7 @@ If it doesn't work, you probably have to investigate it as the behavior may be d
 + Python >= 3.6
 + [PyQuery](https://pypi.python.org/pypi/pyquery/), [javaobj-py3](https://pypi.org/project/javaobj-py3), Pillow, requests
 + [sqlcipher](https://github.com/sqlcipher/sqlcipher) >= 4.1, [pysqlcipher3](https://pypi.python.org/pypi/pysqlcipher3)
-+ sox (command line tool)
++ sox, openssl (command line tools)
 + csscompressor (suggested, optional)
 + Silk audio decoder (included; build with `./third-party/compile_silk.sh`)
 

wechat/parser.py

@@ -100,25 +100,25 @@ SELECT {} FROM message
             md5, group = row
             self.emoji_groups[md5] = group
 
-        NEEDED_EMOJI_CATALOG = [49, 50, 17]
+        HAS_EMOJI_CATALOG = [49, 50, 17]  # these are included in static/
         try:
             emojiinfo_q = self.cc.execute(
-    """ SELECT md5, catalog, name, cdnUrl FROM EmojiInfo""")
+    """ SELECT md5, catalog, name, cdnUrl, encrypturl, aeskey FROM EmojiInfo""")
         except: # old database does not have cdnurl
             emojiinfo_q = self.cc.execute(
     """ SELECT md5, catalog, name FROM EmojiInfo""")
             for row in emojiinfo_q:
                 md5, catalog, name = row
-                if catalog not in NEEDED_EMOJI_CATALOG:
-                    continue
+                if name and catalog in HAS_EMOJI_CATALOG:
                     self.internal_emojis[md5] = name
         else:
             for row in emojiinfo_q:
-                md5, catalog, name, cdnUrl = row
-                if cdnUrl:
-                    self.emoji_url[md5] = cdnUrl
-                if catalog not in NEEDED_EMOJI_CATALOG:
-                    continue
+                md5, catalog, name, cdnUrl, encrypturl, aeskey = row
+                if cdnUrl or encrypturl:
+                    self.emoji_url[md5] = (cdnUrl, encrypturl, aeskey)
+                if not cdnUrl and encrypturl:
+                    logger.warning(f"Emoji {md5} has encrypturl only.")
+                if name and catalog in HAS_EMOJI_CATALOG:
                     self.internal_emojis[md5] = name
 
 

wechat/render.py

@@ -163,7 +163,9 @@ class HTMLRender(object):
                 image_str = get_file_b64(video)
                 format_dict["img"] = (image_str, 'jpeg')
                 return TEMPLATES[TYPE_IMG].format(**format_dict)
-            return f"VIDEO FILE {msg.imgPath}"
+            # fallback
+            format_dict['content'] = f"VIDEO FILE {msg.imgPath}"
+            return TEMPLATES_FILES[TYPE_MSG].format(**format_dict)
         elif msg.type == TYPE_WX_VIDEO:
             # TODO: fetch video from resource
             return fallback()

wechat/res.py

@@ -4,6 +4,7 @@ import glob
 import os
 import re
 from PIL import Image
+import tempfile
 import io
 import base64
 import logging
@@ -16,6 +17,7 @@ import requests
 
 from .avatar import AvatarReader
 from .common.textutil import md5, get_file_b64
+from .common.procutil import subproc_succ
 from .common.timer import timing
 from .msg import TYPE_SPEAK
 from .audio import parse_wechat_audio_file
@@ -46,21 +48,41 @@ class EmojiCache(object):
             data = data.decode('ascii')
         return data, format
 
-    def fetch(self, md5, url):
+    def fetch(self, md5, urls):
+        cdnurl, encrypturl, aeskey = urls
+        if cdnurl:
             try:
-            logger.info("Requesting emoji {} from {} ...".format(md5, url))
-            r = requests.get(url).content
+                logger.info("Requesting emoji {} from {} ...".format(md5, cdnurl))
+                r = requests.get(cdnurl).content
                 im = Image.open(io.BytesIO(r))
-            format = im.format.lower()
-            ret = (base64.b64encode(r).decode('ascii'), format)
-            self.dic[md5] = ret
+                ret = (base64.b64encode(r).decode('ascii'), im.format.lower())
+                self.add(md5, ret)
+                return ret
+            except Exception:
+                logger.exception("Error processing cdnurl {}".format(cdnurl))
 
+        if encrypturl:
+            try:
+                logger.info("Requesting encrypted emoji {} from {} ...".format(md5, encrypturl))
+                buf = requests.get(encrypturl).content
+                with tempfile.TemporaryDirectory(prefix="wechat_dump_download") as d:
+                    fname = os.path.join(d, md5)
+                    with open(fname, 'wb') as f:
+                        f.write(buf)
+                    cmd = f"openssl enc -d -aes-128-cbc -in {fname} -K {aeskey} -iv {aeskey}"
+                    decrypted_buf = subproc_succ(cmd)
+                im = Image.open(io.BytesIO(decrypted_buf))
+                ret = (base64.b64encode(decrypted_buf).decode('ascii'), im.format.lower())
+                self.add(md5, ret)
+                return ret
+            except Exception:
+                logger.exception("Error processing encrypturl {}".format(encrypturl))
+        return None, None
+
+    def add(self, md5, values):
+        self.dic[md5] = values
         if len(self.dic) >= self._curr_size + 10:
             self.flush()
-            return ret
-        except Exception as e:
-            logger.exception("Error processing emoji from {}".format(url))
-            return None, None
 
     def flush(self):
         if len(self.dic) > self._curr_size:
@@ -206,17 +228,10 @@ class Resource(object):
         path = os.path.join(self.emoji_dir, pack_id or '')
         candidates = glob.glob(os.path.join(path, '{}*'.format(md5)))
         candidates = [k for k in candidates if not re.match('.*_[0-9]+$', k)]
-
-        def try_use(f):
-            if not f: return None
-            if not imghdr.what(f[0]):   # cannot recognize file type
-                return None
-            return f[0]
-
         candidates = [k for k in candidates if (allow_cover or (not k.endswith('_cover') and not k.endswith('_thumb')))]
 
         for cand in candidates:
-            if imghdr.what(cand):
+            if imghdr.what(cand):  # does not recognize
                 return get_file_b64(cand), imghdr.what(cand)
         return None, None
 
@@ -243,19 +258,19 @@ class Resource(object):
                 return emoji_img, format
 
             # check url
-            url = self.parser.emoji_url.get(md5, None)
-            if url:
-                emoji_img, format = self.emoji_cache.fetch(md5, url)
+            urls = self.parser.emoji_url.get(md5, None)
+            if urls:
+                emoji_img, format = self.emoji_cache.fetch(md5, urls)
                 if format:
                     return emoji_img, format
 
-            # check resource/emoji dir again, for cover
+            # check resource/emoji dir again, fallback to allow cover/thumbnail
             emoji_img, format = self._get_res_emoji(md5, group, allow_cover=True)
             if format:
                 return emoji_img, format
 
             # TODO: first 1k in emoji is encrypted
-            logger.warn("Cannot get emoji {} in group {}".format(md5, group))
+            logger.warning("Cannot get emoji {} in group {}".format(md5, group))
             return None, None
 
     def get_video(self, videoid):
@@ -265,4 +280,5 @@ class Resource(object):
             return video_file
         elif os.path.exists(video_thumbnail_file):
             return video_thumbnail_file
+        logger.warning(f"Cannot get video {videoid}")
         return ""