yt_dlp/networking/_helper.py

   1 from __future__ import annotations
   2
   3 import contextlib
   4 import functools
   5 import socket
   6 import ssl
   7 import sys
   8 import typing
   9 import urllib.parse
  10 import urllib.request
  11
  12 from .exceptions import RequestError, UnsupportedRequest
  13 from ..dependencies import certifi
  14 from ..socks import ProxyType, sockssocket
  15 from ..utils import format_field, traverse_obj
  16
  17 if typing.TYPE_CHECKING:
  18     from collections.abc import Iterable
  19
  20     from ..utils.networking import HTTPHeaderDict
  21
  22
  23 def ssl_load_certs(context: ssl.SSLContext, use_certifi=True):
  24     if certifi and use_certifi:
  25         context.load_verify_locations(cafile=certifi.where())
  26     else:
  27         try:
  28             context.load_default_certs()
  29         # Work around the issue in load_default_certs when there are bad certificates. See:
  30         # https://github.com/yt-dlp/yt-dlp/issues/1060,
  31         # https://bugs.python.org/issue35665, https://bugs.python.org/issue45312
  32         except ssl.SSLError:
  33             # enum_certificates is not present in mingw python. See https://github.com/yt-dlp/yt-dlp/issues/1151
  34             if sys.platform == 'win32' and hasattr(ssl, 'enum_certificates'):
  35                 for storename in ('CA', 'ROOT'):
  36                     ssl_load_windows_store_certs(context, storename)
  37             context.set_default_verify_paths()
  38
  39
  40 def ssl_load_windows_store_certs(ssl_context, storename):
  41     # Code adapted from _load_windows_store_certs in https://github.com/python/cpython/blob/main/Lib/ssl.py
  42     try:
  43         certs = [cert for cert, encoding, trust in ssl.enum_certificates(storename)
  44                  if encoding == 'x509_asn' and (
  45                      trust is True or ssl.Purpose.SERVER_AUTH.oid in trust)]
  46     except PermissionError:
  47         return
  48     for cert in certs:
  49         with contextlib.suppress(ssl.SSLError):
  50             ssl_context.load_verify_locations(cadata=cert)
  51
  52
  53 def make_socks_proxy_opts(socks_proxy):
  54     url_components = urllib.parse.urlparse(socks_proxy)
  55     if url_components.scheme.lower() == 'socks5':
  56         socks_type = ProxyType.SOCKS5
  57         rdns = False
  58     elif url_components.scheme.lower() == 'socks5h':
  59         socks_type = ProxyType.SOCKS5
  60         rdns = True
  61     elif url_components.scheme.lower() == 'socks4':
  62         socks_type = ProxyType.SOCKS4
  63         rdns = False
  64     elif url_components.scheme.lower() == 'socks4a':
  65         socks_type = ProxyType.SOCKS4A
  66         rdns = True
  67     else:
  68         raise ValueError(f'Unknown SOCKS proxy version: {url_components.scheme.lower()}')
  69
  70     def unquote_if_non_empty(s):
  71         if not s:
  72             return s
  73         return urllib.parse.unquote_plus(s)
  74     return {
  75         'proxytype': socks_type,
  76         'addr': url_components.hostname,
  77         'port': url_components.port or 1080,
  78         'rdns': rdns,
  79         'username': unquote_if_non_empty(url_components.username),
  80         'password': unquote_if_non_empty(url_components.password),
  81     }
  82
  83
  84 def select_proxy(url, proxies):
  85     """Unified proxy selector for all backends"""
  86     url_components = urllib.parse.urlparse(url)
  87     if 'no' in proxies:
  88         hostport = url_components.hostname + format_field(url_components.port, None, ':%s')
  89         if urllib.request.proxy_bypass_environment(hostport, {'no': proxies['no']}):
  90             return
  91         elif urllib.request.proxy_bypass(hostport):  # check system settings
  92             return
  93
  94     return traverse_obj(proxies, url_components.scheme or 'http', 'all')
  95
  96
  97 def get_redirect_method(method, status):
  98     """Unified redirect method handling"""
  99
 100     # A 303 must either use GET or HEAD for subsequent request
 101     # https://datatracker.ietf.org/doc/html/rfc7231#section-6.4.4
 102     if status == 303 and method != 'HEAD':
 103         method = 'GET'
 104     # 301 and 302 redirects are commonly turned into a GET from a POST
 105     # for subsequent requests by browsers, so we'll do the same.
 106     # https://datatracker.ietf.org/doc/html/rfc7231#section-6.4.2
 107     # https://datatracker.ietf.org/doc/html/rfc7231#section-6.4.3
 108     if status in (301, 302) and method == 'POST':
 109         method = 'GET'
 110     return method
 111
 112
 113 def make_ssl_context(
 114     verify=True,
 115     client_certificate=None,
 116     client_certificate_key=None,
 117     client_certificate_password=None,
 118     legacy_support=False,
 119     use_certifi=True,
 120 ):
 121     context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
 122     context.check_hostname = verify
 123     context.verify_mode = ssl.CERT_REQUIRED if verify else ssl.CERT_NONE
 124
 125     # Some servers may reject requests if ALPN extension is not sent. See:
 126     # https://github.com/python/cpython/issues/85140
 127     # https://github.com/yt-dlp/yt-dlp/issues/3878
 128     with contextlib.suppress(NotImplementedError):
 129         context.set_alpn_protocols(['http/1.1'])
 130     if verify:
 131         ssl_load_certs(context, use_certifi)
 132
 133     if legacy_support:
 134         context.options |= 4  # SSL_OP_LEGACY_SERVER_CONNECT
 135         context.set_ciphers('DEFAULT')  # compat
 136
 137     elif ssl.OPENSSL_VERSION_INFO >= (1, 1, 1) and not ssl.OPENSSL_VERSION.startswith('LibreSSL'):
 138         # Use the default SSL ciphers and minimum TLS version settings from Python 3.10 [1].
 139         # This is to ensure consistent behavior across Python versions and libraries, and help avoid fingerprinting
 140         # in some situations [2][3].
 141         # Python 3.10 only supports OpenSSL 1.1.1+ [4]. Because this change is likely
 142         # untested on older versions, we only apply this to OpenSSL 1.1.1+ to be safe.
 143         # LibreSSL is excluded until further investigation due to cipher support issues [5][6].
 144         # 1. https://github.com/python/cpython/commit/e983252b516edb15d4338b0a47631b59ef1e2536
 145         # 2. https://github.com/yt-dlp/yt-dlp/issues/4627
 146         # 3. https://github.com/yt-dlp/yt-dlp/pull/5294
 147         # 4. https://peps.python.org/pep-0644/
 148         # 5. https://peps.python.org/pep-0644/#libressl-support
 149         # 6. https://github.com/yt-dlp/yt-dlp/commit/5b9f253fa0aee996cf1ed30185d4b502e00609c4#commitcomment-89054368
 150         context.set_ciphers(
 151             '@SECLEVEL=2:ECDH+AESGCM:ECDH+CHACHA20:ECDH+AES:DHE+AES:!aNULL:!eNULL:!aDSS:!SHA1:!AESCCM')
 152         context.minimum_version = ssl.TLSVersion.TLSv1_2
 153
 154     if client_certificate:
 155         try:
 156             context.load_cert_chain(
 157                 client_certificate, keyfile=client_certificate_key,
 158                 password=client_certificate_password)
 159         except ssl.SSLError:
 160             raise RequestError('Unable to load client certificate')
 161
 162         if getattr(context, 'post_handshake_auth', None) is not None:
 163             context.post_handshake_auth = True
 164     return context
 165
 166
 167 class InstanceStoreMixin:
 168     def __init__(self, **kwargs):
 169         self.__instances = []
 170         super().__init__(**kwargs)  # So that both MRO works
 171
 172     @staticmethod
 173     def _create_instance(**kwargs):
 174         raise NotImplementedError
 175
 176     def _get_instance(self, **kwargs):
 177         for key, instance in self.__instances:
 178             if key == kwargs:
 179                 return instance
 180
 181         instance = self._create_instance(**kwargs)
 182         self.__instances.append((kwargs, instance))
 183         return instance
 184
 185     def _close_instance(self, instance):
 186         if callable(getattr(instance, 'close', None)):
 187             instance.close()
 188
 189     def _clear_instances(self):
 190         for _, instance in self.__instances:
 191             self._close_instance(instance)
 192         self.__instances.clear()
 193
 194
 195 def add_accept_encoding_header(headers: HTTPHeaderDict, supported_encodings: Iterable[str]):
 196     if 'Accept-Encoding' not in headers:
 197         headers['Accept-Encoding'] = ', '.join(supported_encodings) or 'identity'
 198
 199
 200 def wrap_request_errors(func):
 201     @functools.wraps(func)
 202     def wrapper(self, *args, **kwargs):
 203         try:
 204             return func(self, *args, **kwargs)
 205         except UnsupportedRequest as e:
 206             if e.handler is None:
 207                 e.handler = self
 208             raise
 209     return wrapper
 210
 211
 212 def _socket_connect(ip_addr, timeout, source_address):
 213     af, socktype, proto, canonname, sa = ip_addr
 214     sock = socket.socket(af, socktype, proto)
 215     try:
 216         if timeout is not socket._GLOBAL_DEFAULT_TIMEOUT:
 217             sock.settimeout(timeout)
 218         if source_address:
 219             sock.bind(source_address)
 220         sock.connect(sa)
 221         return sock
 222     except socket.error:
 223         sock.close()
 224         raise
 225
 226
 227 def create_socks_proxy_socket(dest_addr, proxy_args, proxy_ip_addr, timeout, source_address):
 228     af, socktype, proto, canonname, sa = proxy_ip_addr
 229     sock = sockssocket(af, socktype, proto)
 230     try:
 231         connect_proxy_args = proxy_args.copy()
 232         connect_proxy_args.update({'addr': sa[0], 'port': sa[1]})
 233         sock.setproxy(**connect_proxy_args)
 234         if timeout is not socket._GLOBAL_DEFAULT_TIMEOUT:  # noqa: E721
 235             sock.settimeout(timeout)
 236         if source_address:
 237             sock.bind(source_address)
 238         sock.connect(dest_addr)
 239         return sock
 240     except socket.error:
 241         sock.close()
 242         raise
 243
 244
 245 def create_connection(
 246     address,
 247     timeout=socket._GLOBAL_DEFAULT_TIMEOUT,
 248     source_address=None,
 249     *,
 250     _create_socket_func=_socket_connect
 251 ):
 252     # Work around socket.create_connection() which tries all addresses from getaddrinfo() including IPv6.
 253     # This filters the addresses based on the given source_address.
 254     # Based on: https://github.com/python/cpython/blob/main/Lib/socket.py#L810
 255     host, port = address
 256     ip_addrs = socket.getaddrinfo(host, port, 0, socket.SOCK_STREAM)
 257     if not ip_addrs:
 258         raise socket.error('getaddrinfo returns an empty list')
 259     if source_address is not None:
 260         af = socket.AF_INET if ':' not in source_address[0] else socket.AF_INET6
 261         ip_addrs = [addr for addr in ip_addrs if addr[0] == af]
 262         if not ip_addrs:
 263             raise OSError(
 264                 f'No remote IPv{4 if af == socket.AF_INET else 6} addresses available for connect. '
 265                 f'Can\'t use "{source_address[0]}" as source address')
 266
 267     err = None
 268     for ip_addr in ip_addrs:
 269         try:
 270             sock = _create_socket_func(ip_addr, timeout, source_address)
 271             # Explicitly break __traceback__ reference cycle
 272             # https://bugs.python.org/issue36820
 273             err = None
 274             return sock
 275         except socket.error as e:
 276             err = e
 277
 278     try:
 279         raise err
 280     finally:
 281         # Explicitly break __traceback__ reference cycle
 282         # https://bugs.python.org/issue36820
 283         err = None