niceSOFT/python3-requests: A simple, yet elegant, HTTP library.

src/requests/adapters.py
719 строк27 KB
Nate Prewitt
Don't create default SSLContext if ssl module isn't present (#6724)
29 май 2024, 18:23
29 май 2024, 18:23e188799
"""
requests.adapters
~~~~~~~~~~~~~~~~~

This module contains the transport adapters that Requests uses to define
and maintain connections.
"""

import os.path
import socket  # noqa: F401
import typing
import warnings

from urllib3.exceptions import ClosedPoolError, ConnectTimeoutError
from urllib3.exceptions import HTTPError as _HTTPError
from urllib3.exceptions import InvalidHeader as _InvalidHeader
from urllib3.exceptions import (
    LocationValueError,
    MaxRetryError,
    NewConnectionError,
    ProtocolError,
)
from urllib3.exceptions import ProxyError as _ProxyError
from urllib3.exceptions import ReadTimeoutError, ResponseError
from urllib3.exceptions import SSLError as _SSLError
from urllib3.poolmanager import PoolManager, proxy_from_url
from urllib3.util import Timeout as TimeoutSauce
from urllib3.util import parse_url
from urllib3.util.retry import Retry
from urllib3.util.ssl_ import create_urllib3_context

from .auth import _basic_auth_str
from .compat import basestring, urlparse
from .cookies import extract_cookies_to_jar
from .exceptions import (
    ConnectionError,
    ConnectTimeout,
    InvalidHeader,
    InvalidProxyURL,
    InvalidSchema,
    InvalidURL,
    ProxyError,
    ReadTimeout,
    RetryError,
    SSLError,
)
from .models import Response
from .structures import CaseInsensitiveDict
from .utils import (
    DEFAULT_CA_BUNDLE_PATH,
    extract_zipped_paths,
    get_auth_from_url,
    get_encoding_from_headers,
    prepend_scheme_if_needed,
    select_proxy,
    urldefragauth,
)

try:
    from urllib3.contrib.socks import SOCKSProxyManager
except ImportError:

    def SOCKSProxyManager(*args, **kwargs):
        raise InvalidSchema("Missing dependencies for SOCKS support.")


if typing.TYPE_CHECKING:
    from .models import PreparedRequest


DEFAULT_POOLBLOCK = False
DEFAULT_POOLSIZE = 10
DEFAULT_RETRIES = 0
DEFAULT_POOL_TIMEOUT = None


try:
    import ssl  # noqa: F401

    _preloaded_ssl_context = create_urllib3_context()
    _preloaded_ssl_context.load_verify_locations(
        extract_zipped_paths(DEFAULT_CA_BUNDLE_PATH)
    )
except ImportError:
    # Bypass default SSLContext creation when Python
    # interpreter isn't built with the ssl module.
    _preloaded_ssl_context = None


def _urllib3_request_context(
    request: "PreparedRequest",
    verify: "bool | str | None",
    client_cert: "typing.Tuple[str, str] | str | None",
    poolmanager: "PoolManager",
) -> "(typing.Dict[str, typing.Any], typing.Dict[str, typing.Any])":
    host_params = {}
    pool_kwargs = {}
    parsed_request_url = urlparse(request.url)
    scheme = parsed_request_url.scheme.lower()
    port = parsed_request_url.port

    # Determine if we have and should use our default SSLContext
    # to optimize performance on standard requests.
    poolmanager_kwargs = getattr(poolmanager, "connection_pool_kw", {})
    has_poolmanager_ssl_context = poolmanager_kwargs.get("ssl_context")
    should_use_default_ssl_context = (
        _preloaded_ssl_context is not None and not has_poolmanager_ssl_context
    )

    cert_reqs = "CERT_REQUIRED"
    if verify is False:
        cert_reqs = "CERT_NONE"
    elif verify is True and should_use_default_ssl_context:
        pool_kwargs["ssl_context"] = _preloaded_ssl_context
    elif isinstance(verify, str):
        if not os.path.isdir(verify):
            pool_kwargs["ca_certs"] = verify
        else:
            pool_kwargs["ca_cert_dir"] = verify
    pool_kwargs["cert_reqs"] = cert_reqs
    if client_cert is not None:
        if isinstance(client_cert, tuple) and len(client_cert) == 2:
            pool_kwargs["cert_file"] = client_cert[0]
            pool_kwargs["key_file"] = client_cert[1]
        else:
            # According to our docs, we allow users to specify just the client
            # cert path
            pool_kwargs["cert_file"] = client_cert
    host_params = {
        "scheme": scheme,
        "host": parsed_request_url.hostname,
        "port": port,
    }
    return host_params, pool_kwargs


class BaseAdapter:
    """The Base Transport Adapter"""

    def __init__(self):
        super().__init__()

    def send(
        self, request, stream=False, timeout=None, verify=True, cert=None, proxies=None
    ):
        """Sends PreparedRequest object. Returns Response object.

        :param request: The :class:`PreparedRequest <PreparedRequest>` being sent.
        :param stream: (optional) Whether to stream the request content.
        :param timeout: (optional) How long to wait for the server to send
            data before giving up, as a float, or a :ref:`(connect timeout,
            read timeout) <timeouts>` tuple.
        :type timeout: float or tuple
        :param verify: (optional) Either a boolean, in which case it controls whether we verify
            the server's TLS certificate, or a string, in which case it must be a path
            to a CA bundle to use
        :param cert: (optional) Any user-provided SSL certificate to be trusted.
        :param proxies: (optional) The proxies dictionary to apply to the request.
        """
        raise NotImplementedError

    def close(self):
        """Cleans up adapter specific items."""
        raise NotImplementedError


class HTTPAdapter(BaseAdapter):
    """The built-in HTTP Adapter for urllib3.

    Provides a general-case interface for Requests sessions to contact HTTP and
    HTTPS urls by implementing the Transport Adapter interface. This class will
    usually be created by the :class:`Session <Session>` class under the
    covers.

    :param pool_connections: The number of urllib3 connection pools to cache.
    :param pool_maxsize: The maximum number of connections to save in the pool.
    :param max_retries: The maximum number of retries each connection
        should attempt. Note, this applies only to failed DNS lookups, socket
        connections and connection timeouts, never to requests where data has
        made it to the server. By default, Requests does not retry failed
        connections. If you need granular control over the conditions under
        which we retry a request, import urllib3's ``Retry`` class and pass
        that instead.
    :param pool_block: Whether the connection pool should block for connections.

    Usage::

      >>> import requests
      >>> s = requests.Session()
      >>> a = requests.adapters.HTTPAdapter(max_retries=3)
      >>> s.mount('http://', a)
    """

    __attrs__ = [
        "max_retries",
        "config",
        "_pool_connections",
        "_pool_maxsize",
        "_pool_block",
    ]

    def __init__(
        self,
        pool_connections=DEFAULT_POOLSIZE,
        pool_maxsize=DEFAULT_POOLSIZE,
        max_retries=DEFAULT_RETRIES,
        pool_block=DEFAULT_POOLBLOCK,
    ):
        if max_retries == DEFAULT_RETRIES:
            self.max_retries = Retry(0, read=False)
        else:
            self.max_retries = Retry.from_int(max_retries)
        self.config = {}
        self.proxy_manager = {}

        super().__init__()

        self._pool_connections = pool_connections
        self._pool_maxsize = pool_maxsize
        self._pool_block = pool_block

        self.init_poolmanager(pool_connections, pool_maxsize, block=pool_block)

    def __getstate__(self):
        return {attr: getattr(self, attr, None) for attr in self.__attrs__}

    def __setstate__(self, state):
        # Can't handle by adding 'proxy_manager' to self.__attrs__ because
        # self.poolmanager uses a lambda function, which isn't pickleable.
        self.proxy_manager = {}
        self.config = {}

        for attr, value in state.items():
            setattr(self, attr, value)

        self.init_poolmanager(
            self._pool_connections, self._pool_maxsize, block=self._pool_block
        )

    def init_poolmanager(
        self, connections, maxsize, block=DEFAULT_POOLBLOCK, **pool_kwargs
    ):
        """Initializes a urllib3 PoolManager.

        This method should not be called from user code, and is only
        exposed for use when subclassing the
        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.

        :param connections: The number of urllib3 connection pools to cache.
        :param maxsize: The maximum number of connections to save in the pool.
        :param block: Block when no free connections are available.
        :param pool_kwargs: Extra keyword arguments used to initialize the Pool Manager.
        """
        # save these values for pickling
        self._pool_connections = connections
        self._pool_maxsize = maxsize
        self._pool_block = block

        self.poolmanager = PoolManager(
            num_pools=connections,
            maxsize=maxsize,
            block=block,
            **pool_kwargs,
        )

    def proxy_manager_for(self, proxy, **proxy_kwargs):
        """Return urllib3 ProxyManager for the given proxy.

        This method should not be called from user code, and is only
        exposed for use when subclassing the
        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.

        :param proxy: The proxy to return a urllib3 ProxyManager for.
        :param proxy_kwargs: Extra keyword arguments used to configure the Proxy Manager.
        :returns: ProxyManager
        :rtype: urllib3.ProxyManager
        """
        if proxy in self.proxy_manager:
            manager = self.proxy_manager[proxy]
        elif proxy.lower().startswith("socks"):
            username, password = get_auth_from_url(proxy)
            manager = self.proxy_manager[proxy] = SOCKSProxyManager(
                proxy,
                username=username,
                password=password,
                num_pools=self._pool_connections,
                maxsize=self._pool_maxsize,
                block=self._pool_block,
                **proxy_kwargs,
            )
        else:
            proxy_headers = self.proxy_headers(proxy)
            manager = self.proxy_manager[proxy] = proxy_from_url(
                proxy,
                proxy_headers=proxy_headers,
                num_pools=self._pool_connections,
                maxsize=self._pool_maxsize,
                block=self._pool_block,
                **proxy_kwargs,
            )

        return manager

    def cert_verify(self, conn, url, verify, cert):
        """Verify a SSL certificate. This method should not be called from user
        code, and is only exposed for use when subclassing the
        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.

        :param conn: The urllib3 connection object associated with the cert.
        :param url: The requested URL.
        :param verify: Either a boolean, in which case it controls whether we verify
            the server's TLS certificate, or a string, in which case it must be a path
            to a CA bundle to use
        :param cert: The SSL certificate to verify.
        """
        if url.lower().startswith("https") and verify:
            conn.cert_reqs = "CERT_REQUIRED"

            # Only load the CA certificates if 'verify' is a string indicating the CA bundle to use.
            # Otherwise, if verify is a boolean, we don't load anything since
            # the connection will be using a context with the default certificates already loaded,
            # and this avoids a call to the slow load_verify_locations()
            if verify is not True:
                # `verify` must be a str with a path then
                cert_loc = verify

                if not os.path.exists(cert_loc):
                    raise OSError(
                        f"Could not find a suitable TLS CA certificate bundle, "
                        f"invalid path: {cert_loc}"
                    )

                if not os.path.isdir(cert_loc):
                    conn.ca_certs = cert_loc
                else:
                    conn.ca_cert_dir = cert_loc
        else:
            conn.cert_reqs = "CERT_NONE"
            conn.ca_certs = None
            conn.ca_cert_dir = None

        if cert:
            if not isinstance(cert, basestring):
                conn.cert_file = cert[0]
                conn.key_file = cert[1]
            else:
                conn.cert_file = cert
                conn.key_file = None
            if conn.cert_file and not os.path.exists(conn.cert_file):
                raise OSError(
                    f"Could not find the TLS certificate file, "
                    f"invalid path: {conn.cert_file}"
                )
            if conn.key_file and not os.path.exists(conn.key_file):
                raise OSError(
                    f"Could not find the TLS key file, invalid path: {conn.key_file}"
                )

    def build_response(self, req, resp):
        """Builds a :class:`Response <requests.Response>` object from a urllib3
        response. This should not be called from user code, and is only exposed
        for use when subclassing the
        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`

        :param req: The :class:`PreparedRequest <PreparedRequest>` used to generate the response.
        :param resp: The urllib3 response object.
        :rtype: requests.Response
        """
        response = Response()

        # Fallback to None if there's no status_code, for whatever reason.
        response.status_code = getattr(resp, "status", None)

        # Make headers case-insensitive.
        response.headers = CaseInsensitiveDict(getattr(resp, "headers", {}))

        # Set encoding.
        response.encoding = get_encoding_from_headers(response.headers)
        response.raw = resp
        response.reason = response.raw.reason

        if isinstance(req.url, bytes):
            response.url = req.url.decode("utf-8")
        else:
            response.url = req.url

        # Add new cookies from the server.
        extract_cookies_to_jar(response.cookies, req, resp)

        # Give the Response some context.
        response.request = req
        response.connection = self

        return response

    def build_connection_pool_key_attributes(self, request, verify, cert=None):
        """Build the PoolKey attributes used by urllib3 to return a connection.

        This looks at the PreparedRequest, the user-specified verify value,
        and the value of the cert parameter to determine what PoolKey values
        to use to select a connection from a given urllib3 Connection Pool.

        The SSL related pool key arguments are not consistently set. As of
        this writing, use the following to determine what keys may be in that
        dictionary:

        * If ``verify`` is ``True``, ``"ssl_context"`` will be set and will be the
          default Requests SSL Context
        * If ``verify`` is ``False``, ``"ssl_context"`` will not be set but
          ``"cert_reqs"`` will be set
        * If ``verify`` is a string, (i.e., it is a user-specified trust bundle)
          ``"ca_certs"`` will be set if the string is not a directory recognized
          by :py:func:`os.path.isdir`, otherwise ``"ca_certs_dir"`` will be
          set.
        * If ``"cert"`` is specified, ``"cert_file"`` will always be set. If
          ``"cert"`` is a tuple with a second item, ``"key_file"`` will also
          be present

        To override these settings, one may subclass this class, call this
        method and use the above logic to change parameters as desired. For
        example, if one wishes to use a custom :py:class:`ssl.SSLContext` one
        must both set ``"ssl_context"`` and based on what else they require,
        alter the other keys to ensure the desired behaviour.

        :param request:
            The PreparedReqest being sent over the connection.
        :type request:
            :class:`~requests.models.PreparedRequest`
        :param verify:
            Either a boolean, in which case it controls whether
            we verify the server's TLS certificate, or a string, in which case it
            must be a path to a CA bundle to use.
        :param cert:
            (optional) Any user-provided SSL certificate for client
            authentication (a.k.a., mTLS). This may be a string (i.e., just
            the path to a file which holds both certificate and key) or a
            tuple of length 2 with the certificate file path and key file
            path.
        :returns:
            A tuple of two dictionaries. The first is the "host parameters"
            portion of the Pool Key including scheme, hostname, and port. The
            second is a dictionary of SSLContext related parameters.
        """
        return _urllib3_request_context(request, verify, cert, self.poolmanager)

    def get_connection_with_tls_context(self, request, verify, proxies=None, cert=None):
        """Returns a urllib3 connection for the given request and TLS settings.
        This should not be called from user code, and is only exposed for use
        when subclassing the :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.

        :param request:
            The :class:`PreparedRequest <PreparedRequest>` object to be sent
            over the connection.
        :param verify:
            Either a boolean, in which case it controls whether we verify the
            server's TLS certificate, or a string, in which case it must be a
            path to a CA bundle to use.
        :param proxies:
            (optional) The proxies dictionary to apply to the request.
        :param cert:
            (optional) Any user-provided SSL certificate to be used for client
            authentication (a.k.a., mTLS).
        :rtype:
            urllib3.ConnectionPool
        """
        proxy = select_proxy(request.url, proxies)
        try:
            host_params, pool_kwargs = self.build_connection_pool_key_attributes(
                request,
                verify,
                cert,
            )
        except ValueError as e:
            raise InvalidURL(e, request=request)
        if proxy:
            proxy = prepend_scheme_if_needed(proxy, "http")
            proxy_url = parse_url(proxy)
            if not proxy_url.host:
                raise InvalidProxyURL(
                    "Please check proxy URL. It is malformed "
                    "and could be missing the host."
                )
            proxy_manager = self.proxy_manager_for(proxy)
            conn = proxy_manager.connection_from_host(
                **host_params, pool_kwargs=pool_kwargs
            )
        else:
            # Only scheme should be lower case
            conn = self.poolmanager.connection_from_host(
                **host_params, pool_kwargs=pool_kwargs
            )

        return conn

    def get_connection(self, url, proxies=None):
        """DEPRECATED: Users should move to `get_connection_with_tls_context`
        for all subclasses of HTTPAdapter using Requests>=2.32.2.

        Returns a urllib3 connection for the given URL. This should not be
        called from user code, and is only exposed for use when subclassing the
        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.

        :param url: The URL to connect to.
        :param proxies: (optional) A Requests-style dictionary of proxies used on this request.
        :rtype: urllib3.ConnectionPool
        """
        warnings.warn(
            (
                "`get_connection` has been deprecated in favor of "
                "`get_connection_with_tls_context`. Custom HTTPAdapter subclasses "
                "will need to migrate for Requests>=2.32.2. Please see "
                "https://github.com/psf/requests/pull/6710 for more details."
            ),
            DeprecationWarning,
        )
        proxy = select_proxy(url, proxies)

        if proxy:
            proxy = prepend_scheme_if_needed(proxy, "http")
            proxy_url = parse_url(proxy)
            if not proxy_url.host:
                raise InvalidProxyURL(
                    "Please check proxy URL. It is malformed "
                    "and could be missing the host."
                )
            proxy_manager = self.proxy_manager_for(proxy)
            conn = proxy_manager.connection_from_url(url)
        else:
            # Only scheme should be lower case
            parsed = urlparse(url)
            url = parsed.geturl()
            conn = self.poolmanager.connection_from_url(url)

        return conn

    def close(self):
        """Disposes of any internal state.

        Currently, this closes the PoolManager and any active ProxyManager,
        which closes any pooled connections.
        """
        self.poolmanager.clear()
        for proxy in self.proxy_manager.values():
            proxy.clear()

    def request_url(self, request, proxies):
        """Obtain the url to use when making the final request.

        If the message is being sent through a HTTP proxy, the full URL has to
        be used. Otherwise, we should only use the path portion of the URL.

        This should not be called from user code, and is only exposed for use
        when subclassing the
        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.

        :param request: The :class:`PreparedRequest <PreparedRequest>` being sent.
        :param proxies: A dictionary of schemes or schemes and hosts to proxy URLs.
        :rtype: str
        """
        proxy = select_proxy(request.url, proxies)
        scheme = urlparse(request.url).scheme

        is_proxied_http_request = proxy and scheme != "https"
        using_socks_proxy = False
        if proxy:
            proxy_scheme = urlparse(proxy).scheme.lower()
            using_socks_proxy = proxy_scheme.startswith("socks")

        url = request.path_url
        if url.startswith("//"):  # Don't confuse urllib3
            url = f"/{url.lstrip('/')}"

        if is_proxied_http_request and not using_socks_proxy:
            url = urldefragauth(request.url)

        return url

    def add_headers(self, request, **kwargs):
        """Add any headers needed by the connection. As of v2.0 this does
        nothing by default, but is left for overriding by users that subclass
        the :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.

        This should not be called from user code, and is only exposed for use
        when subclassing the
        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.

        :param request: The :class:`PreparedRequest <PreparedRequest>` to add headers to.
        :param kwargs: The keyword arguments from the call to send().
        """
        pass

    def proxy_headers(self, proxy):
        """Returns a dictionary of the headers to add to any request sent
        through a proxy. This works with urllib3 magic to ensure that they are
        correctly sent to the proxy, rather than in a tunnelled request if
        CONNECT is being used.

        This should not be called from user code, and is only exposed for use
        when subclassing the
        :class:`HTTPAdapter <requests.adapters.HTTPAdapter>`.

        :param proxy: The url of the proxy being used for this request.
        :rtype: dict
        """
        headers = {}
        username, password = get_auth_from_url(proxy)

        if username:
            headers["Proxy-Authorization"] = _basic_auth_str(username, password)

        return headers

    def send(
        self, request, stream=False, timeout=None, verify=True, cert=None, proxies=None
    ):
        """Sends PreparedRequest object. Returns Response object.

        :param request: The :class:`PreparedRequest <PreparedRequest>` being sent.
        :param stream: (optional) Whether to stream the request content.
        :param timeout: (optional) How long to wait for the server to send
            data before giving up, as a float, or a :ref:`(connect timeout,
            read timeout) <timeouts>` tuple.
        :type timeout: float or tuple or urllib3 Timeout object
        :param verify: (optional) Either a boolean, in which case it controls whether
            we verify the server's TLS certificate, or a string, in which case it
            must be a path to a CA bundle to use
        :param cert: (optional) Any user-provided SSL certificate to be trusted.
        :param proxies: (optional) The proxies dictionary to apply to the request.
        :rtype: requests.Response
        """

        try:
            conn = self.get_connection_with_tls_context(
                request, verify, proxies=proxies, cert=cert
            )
        except LocationValueError as e:
            raise InvalidURL(e, request=request)

        self.cert_verify(conn, request.url, verify, cert)
        url = self.request_url(request, proxies)
        self.add_headers(
            request,
            stream=stream,
            timeout=timeout,
            verify=verify,
            cert=cert,
            proxies=proxies,
        )

        chunked = not (request.body is None or "Content-Length" in request.headers)

        if isinstance(timeout, tuple):
            try:
                connect, read = timeout
                timeout = TimeoutSauce(connect=connect, read=read)
            except ValueError:
                raise ValueError(
                    f"Invalid timeout {timeout}. Pass a (connect, read) timeout tuple, "
                    f"or a single float to set both timeouts to the same value."
                )
        elif isinstance(timeout, TimeoutSauce):
            pass
        else:
            timeout = TimeoutSauce(connect=timeout, read=timeout)

        try:
            resp = conn.urlopen(
                method=request.method,
                url=url,
                body=request.body,
                headers=request.headers,
                redirect=False,
                assert_same_host=False,
                preload_content=False,
                decode_content=False,
                retries=self.max_retries,
                timeout=timeout,
                chunked=chunked,
            )

        except (ProtocolError, OSError) as err:
            raise ConnectionError(err, request=request)

        except MaxRetryError as e:
            if isinstance(e.reason, ConnectTimeoutError):
                # TODO: Remove this in 3.0.0: see #2811
                if not isinstance(e.reason, NewConnectionError):
                    raise ConnectTimeout(e, request=request)

            if isinstance(e.reason, ResponseError):
                raise RetryError(e, request=request)

            if isinstance(e.reason, _ProxyError):
                raise ProxyError(e, request=request)

            if isinstance(e.reason, _SSLError):
                # This branch is for urllib3 v1.22 and later.
                raise SSLError(e, request=request)

            raise ConnectionError(e, request=request)

        except ClosedPoolError as e:
            raise ConnectionError(e, request=request)

        except _ProxyError as e:
            raise ProxyError(e)

        except (_SSLError, _HTTPError) as e:
            if isinstance(e, _SSLError):
                # This branch is for urllib3 versions earlier than v1.22
                raise SSLError(e, request=request)
            elif isinstance(e, ReadTimeoutError):
                raise ReadTimeout(e, request=request)
            elif isinstance(e, _InvalidHeader):
                raise InvalidHeader(e, request=request)
            else:
                raise

        return self.build_response(request, resp)