What causes "pycryptodomex not found. Please install it." in ytdl-org/youtube-dl?

ytdl-org/youtube-dl · error · ExtractorError

pycryptodomex not found. Please install it.

Error message

pycryptodomex not found. Please install it.

What it means

Raised by the ivi.ru extractor when the Cryptodome library (pycryptodomex) is not importable. The signed-request variant of ivi's light API requires Cryptodome.Cipher.Blowfish and Cryptodome.Hash.CMAC to compute the request signature; without it the extractor cannot authenticate the request.

Source

Thrown at youtube_dl/extractor/ivi.py:148

                'Downloading video JSON', data=content_data, query=query)

            error = video_json.get('error')
            if error:
                origin = error.get('origin')
                message = error.get('message') or error.get('user_message')
                extractor_msg = 'Unable to download video %s'
                if origin == 'NotAllowedForLocation':
                    self.raise_geo_restricted(message, self._GEO_COUNTRIES)
                elif origin == 'NoRedisValidData':
                    extractor_msg = 'Video %s does not exist'
                elif site == 353:
                    continue
                elif bundled:
                    raise ExtractorError(
                        'This feature does not work from bundled exe. Run youtube-dl from sources.',
                        expected=True)
                elif not pycryptodomex_found:
                    raise ExtractorError(
                        'pycryptodomex not found. Please install it.',
                        expected=True)
                elif message:
                    extractor_msg += ': ' + message
                raise ExtractorError(extractor_msg % video_id, expected=True)
            else:
                break

        result = video_json['result']
        title = result['title']

        quality = qualities(self._KNOWN_FORMATS)

        formats = []
        for f in result.get('files', []):
            f_url = f.get('url')
            content_format = f.get('content_format')
            if not f_url or '-MDRM-' in content_format or '-FPS-' in content_format:

View on GitHub (pinned to 956b8c5855)

Solutions

pip install pycryptodomex
Verify the import works: python -c "from Cryptodome.Hash import CMAC"
Do not substitute the old 'pycrypto' package - the code imports the Cryptodome namespace.

Example fix

// before
pip install youtube-dl
youtube-dl 'http://www.ivi.ru/watch/12345'
# => pycryptodomex not found. Please install it.

// after
pip install pycryptodomex
youtube-dl 'http://www.ivi.ru/watch/12345'

Defensive patterns

Strategy: validation

Validate before calling

try:
    from Cryptodome.Hash import CMAC  # noqa
    from Cryptodome.Cipher import Blowfish  # noqa
    pycryptodomex_ok = True
except ImportError:
    pycryptodomex_ok = False
if not pycryptodomex_ok and url_host_is('ivi.ru'):
    raise EnvironmentError('pip install pycryptodomex before extracting ivi')

Try / catch

try:
    ydl.extract_info(ivi_url)
except ExtractorError as e:
    if 'pycryptodomex not found' in str(e):
        abort_with_hint('pip install pycryptodomex')  # environment fix, then re-run

Prevention

Add pycryptodomex to requirements alongside youtube-dl.
Check the Cryptodome import in CI for environments that will touch ivi URLs.
Remember the namespace is Cryptodome, not Crypto - installing old pycrypto does not help.

When it happens

Trigger: from Cryptodome.Cipher import Blowfish / from Cryptodome.Hash import CMAC raise ImportError (pycryptodomex_found = False), the unsigned site-183 request then returns an API error, and the handler reports the missing dependency.

Common situations: Minimal Python environments, source installs where only pycrypto (not pycryptodomex) is present, or virtualenvs created without the extras.

Related errors

AI-assisted analysis of ytdl-org/youtube-dl@956b8c5855 (2026-08-14). Data as JSON: /api/errors/d21d79b7a65130f4. Report an issue: GitHub.