diff options
Diffstat (limited to 'youtube_dl/utils.py')
| -rw-r--r-- | youtube_dl/utils.py | 173 |
1 files changed, 148 insertions, 25 deletions
diff --git a/youtube_dl/utils.py b/youtube_dl/utils.py index 113c913df..3ec9d3811 100644 --- a/youtube_dl/utils.py +++ b/youtube_dl/utils.py @@ -1717,21 +1717,6 @@ TIMEZONE_NAMES = { 'PST': -8, 'PDT': -7 # Pacific } -KNOWN_EXTENSIONS = ( - 'mp4', 'm4a', 'm4p', 'm4b', 'm4r', 'm4v', 'aac', - 'flv', 'f4v', 'f4a', 'f4b', - 'webm', 'ogg', 'ogv', 'oga', 'ogx', 'spx', 'opus', - 'mkv', 'mka', 'mk3d', - 'avi', 'divx', - 'mov', - 'asf', 'wmv', 'wma', - '3gp', '3g2', - 'mp3', - 'flac', - 'ape', - 'wav', - 'f4f', 'f4m', 'm3u8', 'smil') - # needed for sanitizing filenames in restricted mode ACCENT_CHARS = dict(zip('ÂÃÄÀÁÅÆÇÈÉÊËÌÍÎÏÐÑÒÓÔÕÖŐØŒÙÚÛÜŰÝÞßàáâãäåæçèéêëìíîïðñòóôõöőøœùúûüűýþÿ', itertools.chain('AAAAAA', ['AE'], 'CEEEEIIIIDNOOOOOOO', ['OE'], 'UUUUUY', ['TH', 'ss'], @@ -3959,19 +3944,22 @@ def parse_duration(s): return duration -def prepend_extension(filename, ext, expected_real_ext=None): +def _change_extension(prepend, filename, ext, expected_real_ext=None): name, real_ext = os.path.splitext(filename) - return ( - '{0}.{1}{2}'.format(name, ext, real_ext) - if not expected_real_ext or real_ext[1:] == expected_real_ext - else '{0}.{1}'.format(filename, ext)) + sanitize_extension = _UnsafeExtensionError.sanitize_extension + if not expected_real_ext or real_ext.partition('.')[0::2] == ('', expected_real_ext): + filename = name + if prepend and real_ext: + sanitize_extension(ext, prepend=prepend) + return ''.join((filename, '.', ext, real_ext)) -def replace_extension(filename, ext, expected_real_ext=None): - name, real_ext = os.path.splitext(filename) - return '{0}.{1}'.format( - name if not expected_real_ext or real_ext[1:] == expected_real_ext else filename, - ext) + # Mitigate path traversal and file impersonation attacks + return '.'.join((filename, sanitize_extension(ext))) + + +prepend_extension = functools.partial(_change_extension, True) +replace_extension = functools.partial(_change_extension, False) def check_executable(exe, args=[]): @@ -6561,3 +6549,138 @@ def join_nonempty(*values, **kwargs): if from_dict is not None: values = (traverse_obj(from_dict, variadic(v)) for v in values) return delim.join(map(compat_str, filter(None, values))) + + +class Namespace(object): + """Immutable namespace""" + + def __init__(self, **kw_attr): + self.__dict__.update(kw_attr) + + def __iter__(self): + return iter(self.__dict__.values()) + + @property + def items_(self): + return self.__dict__.items() + + +MEDIA_EXTENSIONS = Namespace( + common_video=('avi', 'flv', 'mkv', 'mov', 'mp4', 'webm'), + video=('3g2', '3gp', 'f4v', 'mk3d', 'divx', 'mpg', 'ogv', 'm4v', 'wmv'), + common_audio=('aiff', 'alac', 'flac', 'm4a', 'mka', 'mp3', 'ogg', 'opus', 'wav'), + audio=('aac', 'ape', 'asf', 'f4a', 'f4b', 'm4b', 'm4p', 'm4r', 'oga', 'ogx', 'spx', 'vorbis', 'wma', 'weba'), + thumbnails=('jpg', 'png', 'webp'), + # storyboards=('mhtml', ), + subtitles=('srt', 'vtt', 'ass', 'lrc', 'ttml'), + manifests=('f4f', 'f4m', 'm3u8', 'smil', 'mpd'), +) +MEDIA_EXTENSIONS.video = MEDIA_EXTENSIONS.common_video + MEDIA_EXTENSIONS.video +MEDIA_EXTENSIONS.audio = MEDIA_EXTENSIONS.common_audio + MEDIA_EXTENSIONS.audio + +KNOWN_EXTENSIONS = ( + MEDIA_EXTENSIONS.video + MEDIA_EXTENSIONS.audio + + MEDIA_EXTENSIONS.manifests +) + + +class _UnsafeExtensionError(Exception): + """ + Mitigation exception for unwanted file overwrite/path traversal + + Ref: https://github.com/yt-dlp/yt-dlp/security/advisories/GHSA-79w7-vh3h-8g4j + """ + _ALLOWED_EXTENSIONS = frozenset(itertools.chain( + ( # internal + 'description', + 'json', + 'meta', + 'orig', + 'part', + 'temp', + 'uncut', + 'unknown_video', + 'ytdl', + ), + # video + MEDIA_EXTENSIONS.video, ( + 'avif', + 'ismv', + 'm2ts', + 'm4s', + 'mng', + 'mpeg', + 'qt', + 'swf', + 'ts', + 'vp9', + 'wvm', + ), + # audio + MEDIA_EXTENSIONS.audio, ( + 'isma', + 'mid', + 'mpga', + 'ra', + ), + # image + MEDIA_EXTENSIONS.thumbnails, ( + 'bmp', + 'gif', + 'ico', + 'heic', + 'jng', + 'jpeg', + 'jxl', + 'svg', + 'tif', + 'wbmp', + ), + # subtitle + MEDIA_EXTENSIONS.subtitles, ( + 'dfxp', + 'fs', + 'ismt', + 'sami', + 'scc', + 'ssa', + 'tt', + ), + # others + MEDIA_EXTENSIONS.manifests, + ( + # not used in yt-dl + # *MEDIA_EXTENSIONS.storyboards, + # 'desktop', + # 'ism', + # 'm3u', + # 'sbv', + # 'swp', + # 'url', + # 'webloc', + # 'xml', + ))) + + def __init__(self, extension): + super(_UnsafeExtensionError, self).__init__('unsafe file extension: {0!r}'.format(extension)) + self.extension = extension + + # support --no-check-extensions + lenient = False + + @classmethod + def sanitize_extension(cls, extension, **kwargs): + # ... /, *, prepend=False + prepend = kwargs.get('prepend', False) + + if '/' in extension or '\\' in extension: + raise cls(extension) + + if not prepend: + last = extension.rpartition('.')[-1] + if last == 'bin': + extension = last = 'unknown_video' + if not (cls.lenient or last.lower() in cls._ALLOWED_EXTENSIONS): + raise cls(extension) + + return extension |