[hls,aes] Fallback to native implementation for AES-CBC

and detect `Cryptodome` in addition to `Crypto`

Closes #935
Related: #938

yt_dlp/downloader/external.py

@@ -6,13 +6,8 @@ import subprocess
 import sys
 import time
 
-try:
-    from Crypto.Cipher import AES
-    can_decrypt_frag = True
-except ImportError:
-    can_decrypt_frag = False
-
 from .common import FileDownloader
+from ..aes import aes_cbc_decrypt_bytes
 from ..compat import (
     compat_setenv,
     compat_str,
@@ -164,8 +159,7 @@ class ExternalFD(FileDownloader):
                         decrypt_info['KEY'] = decrypt_info.get('KEY') or self.ydl.urlopen(
                             self._prepare_url(info_dict, info_dict.get('_decryption_key_url') or decrypt_info['URI'])).read()
                         encrypted_data = src.read()
-                        decrypted_data = AES.new(
-                            decrypt_info['KEY'], AES.MODE_CBC, iv).decrypt(encrypted_data)
+                        decrypted_data = aes_cbc_decrypt_bytes(encrypted_data, decrypt_info['KEY'], iv)
                         dest.write(decrypted_data)
                     else:
                         fragment_data = src.read()

yt_dlp/downloader/fragment.py

@@ -4,12 +4,6 @@ import os
 import time
 import json
 
-try:
-    from Crypto.Cipher import AES
-    can_decrypt_frag = True
-except ImportError:
-    can_decrypt_frag = False
-
 try:
     import concurrent.futures
     can_threaded_download = True
@@ -18,6 +12,7 @@ except ImportError:
 
 from .common import FileDownloader
 from .http import HttpFD
+from ..aes import aes_cbc_decrypt_bytes
 from ..compat import (
     compat_urllib_error,
     compat_struct_pack,
@@ -386,7 +381,7 @@ class FragmentFD(FileDownloader):
             # not what it decrypts to.
             if self.params.get('test', False):
                 return frag_content
-            return AES.new(decrypt_info['KEY'], AES.MODE_CBC, iv).decrypt(frag_content)
+            return aes_cbc_decrypt_bytes(frag_content, decrypt_info['KEY'], iv)
 
         def append_fragment(frag_content, frag_index, ctx):
             if not frag_content:

yt_dlp/downloader/hls.py

@@ -5,7 +5,7 @@ import io
 import binascii
 
 from ..downloader import get_suitable_downloader
-from .fragment import FragmentFD, can_decrypt_frag
+from .fragment import FragmentFD
 from .external import FFmpegFD
 
 from ..compat import (
@@ -29,7 +29,7 @@ class HlsFD(FragmentFD):
     FD_NAME = 'hlsnative'
 
     @staticmethod
-    def can_download(manifest, info_dict, allow_unplayable_formats=False, with_crypto=can_decrypt_frag):
+    def can_download(manifest, info_dict, allow_unplayable_formats=False):
         UNSUPPORTED_FEATURES = [
             # r'#EXT-X-BYTERANGE',  # playlists composed of byte ranges of media files [2]
 
@@ -57,7 +57,6 @@ class HlsFD(FragmentFD):
         def check_results():
             yield not info_dict.get('is_live')
             is_aes128_enc = '#EXT-X-KEY:METHOD=AES-128' in manifest
-            yield with_crypto or not is_aes128_enc
             yield not (is_aes128_enc and r'#EXT-X-BYTERANGE' in manifest)
             for feature in UNSUPPORTED_FEATURES:
                 yield not re.search(feature, manifest)
@@ -75,8 +74,6 @@ class HlsFD(FragmentFD):
             if info_dict.get('extra_param_to_segment_url') or info_dict.get('_decryption_key_url'):
                 self.report_error('pycryptodome not found. Please install')
                 return False
-            if self.can_download(s, info_dict, with_crypto=True):
-                self.report_warning('pycryptodome is needed to download this file natively')
             fd = FFmpegFD(self.ydl, self.params)
             self.report_warning(
                 '%s detected unsupported features; extraction will be delegated to %s' % (self.FD_NAME, fd.get_basename()))