--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/urllib3/contrib/pyopenssl.py	Sun May 05 23:32:17 2024 -0400
@@ -0,0 +1,548 @@
+"""
+Module for using pyOpenSSL as a TLS backend. This module was relevant before
+the standard library ``ssl`` module supported SNI, but now that we've dropped
+support for Python 2.7 all relevant Python versions support SNI so
+**this module is no longer recommended**.
+
+This needs the following packages installed:
+
+* `pyOpenSSL`_ (tested with 16.0.0)
+* `cryptography`_ (minimum 1.3.4, from pyopenssl)
+* `idna`_ (minimum 2.0)
+
+However, pyOpenSSL depends on cryptography, so while we use all three directly here we
+end up having relatively few packages required.
+
+You can install them with the following command:
+
+.. code-block:: bash
+
+    $ python -m pip install pyopenssl cryptography idna
+
+To activate certificate checking, call
+:func:`~urllib3.contrib.pyopenssl.inject_into_urllib3` from your Python code
+before you begin making HTTP requests. This can be done in a ``sitecustomize``
+module, or at any other time before your application begins using ``urllib3``,
+like this:
+
+.. code-block:: python
+
+    try:
+        import urllib3.contrib.pyopenssl
+        urllib3.contrib.pyopenssl.inject_into_urllib3()
+    except ImportError:
+        pass
+
+.. _pyopenssl: https://www.pyopenssl.org
+.. _cryptography: https://cryptography.io
+.. _idna: https://github.com/kjd/idna
+"""
+
+from __future__ import annotations
+
+import OpenSSL.SSL  # type: ignore[import-untyped]
+from cryptography import x509
+
+try:
+    from cryptography.x509 import UnsupportedExtension  # type: ignore[attr-defined]
+except ImportError:
+    # UnsupportedExtension is gone in cryptography >= 2.1.0
+    class UnsupportedExtension(Exception):  # type: ignore[no-redef]
+        pass
+
+
+import logging
+import ssl
+import typing
+from io import BytesIO
+from socket import socket as socket_cls
+from socket import timeout
+
+from .. import util
+
+if typing.TYPE_CHECKING:
+    from OpenSSL.crypto import X509  # type: ignore[import-untyped]
+
+
+__all__ = ["inject_into_urllib3", "extract_from_urllib3"]
+
+# Map from urllib3 to PyOpenSSL compatible parameter-values.
+_openssl_versions: dict[int, int] = {
+    util.ssl_.PROTOCOL_TLS: OpenSSL.SSL.SSLv23_METHOD,  # type: ignore[attr-defined]
+    util.ssl_.PROTOCOL_TLS_CLIENT: OpenSSL.SSL.SSLv23_METHOD,  # type: ignore[attr-defined]
+    ssl.PROTOCOL_TLSv1: OpenSSL.SSL.TLSv1_METHOD,
+}
+
+if hasattr(ssl, "PROTOCOL_TLSv1_1") and hasattr(OpenSSL.SSL, "TLSv1_1_METHOD"):
+    _openssl_versions[ssl.PROTOCOL_TLSv1_1] = OpenSSL.SSL.TLSv1_1_METHOD
+
+if hasattr(ssl, "PROTOCOL_TLSv1_2") and hasattr(OpenSSL.SSL, "TLSv1_2_METHOD"):
+    _openssl_versions[ssl.PROTOCOL_TLSv1_2] = OpenSSL.SSL.TLSv1_2_METHOD
+
+
+_stdlib_to_openssl_verify = {
+    ssl.CERT_NONE: OpenSSL.SSL.VERIFY_NONE,
+    ssl.CERT_OPTIONAL: OpenSSL.SSL.VERIFY_PEER,
+    ssl.CERT_REQUIRED: OpenSSL.SSL.VERIFY_PEER
+    + OpenSSL.SSL.VERIFY_FAIL_IF_NO_PEER_CERT,
+}
+_openssl_to_stdlib_verify = {v: k for k, v in _stdlib_to_openssl_verify.items()}
+
+# The SSLvX values are the most likely to be missing in the future
+# but we check them all just to be sure.
+_OP_NO_SSLv2_OR_SSLv3: int = getattr(OpenSSL.SSL, "OP_NO_SSLv2", 0) | getattr(
+    OpenSSL.SSL, "OP_NO_SSLv3", 0
+)
+_OP_NO_TLSv1: int = getattr(OpenSSL.SSL, "OP_NO_TLSv1", 0)
+_OP_NO_TLSv1_1: int = getattr(OpenSSL.SSL, "OP_NO_TLSv1_1", 0)
+_OP_NO_TLSv1_2: int = getattr(OpenSSL.SSL, "OP_NO_TLSv1_2", 0)
+_OP_NO_TLSv1_3: int = getattr(OpenSSL.SSL, "OP_NO_TLSv1_3", 0)
+
+_openssl_to_ssl_minimum_version: dict[int, int] = {
+    ssl.TLSVersion.MINIMUM_SUPPORTED: _OP_NO_SSLv2_OR_SSLv3,
+    ssl.TLSVersion.TLSv1: _OP_NO_SSLv2_OR_SSLv3,
+    ssl.TLSVersion.TLSv1_1: _OP_NO_SSLv2_OR_SSLv3 | _OP_NO_TLSv1,
+    ssl.TLSVersion.TLSv1_2: _OP_NO_SSLv2_OR_SSLv3 | _OP_NO_TLSv1 | _OP_NO_TLSv1_1,
+    ssl.TLSVersion.TLSv1_3: (
+        _OP_NO_SSLv2_OR_SSLv3 | _OP_NO_TLSv1 | _OP_NO_TLSv1_1 | _OP_NO_TLSv1_2
+    ),
+    ssl.TLSVersion.MAXIMUM_SUPPORTED: (
+        _OP_NO_SSLv2_OR_SSLv3 | _OP_NO_TLSv1 | _OP_NO_TLSv1_1 | _OP_NO_TLSv1_2
+    ),
+}
+_openssl_to_ssl_maximum_version: dict[int, int] = {
+    ssl.TLSVersion.MINIMUM_SUPPORTED: (
+        _OP_NO_SSLv2_OR_SSLv3
+        | _OP_NO_TLSv1
+        | _OP_NO_TLSv1_1
+        | _OP_NO_TLSv1_2
+        | _OP_NO_TLSv1_3
+    ),
+    ssl.TLSVersion.TLSv1: (
+        _OP_NO_SSLv2_OR_SSLv3 | _OP_NO_TLSv1_1 | _OP_NO_TLSv1_2 | _OP_NO_TLSv1_3
+    ),
+    ssl.TLSVersion.TLSv1_1: _OP_NO_SSLv2_OR_SSLv3 | _OP_NO_TLSv1_2 | _OP_NO_TLSv1_3,
+    ssl.TLSVersion.TLSv1_2: _OP_NO_SSLv2_OR_SSLv3 | _OP_NO_TLSv1_3,
+    ssl.TLSVersion.TLSv1_3: _OP_NO_SSLv2_OR_SSLv3,
+    ssl.TLSVersion.MAXIMUM_SUPPORTED: _OP_NO_SSLv2_OR_SSLv3,
+}
+
+# OpenSSL will only write 16K at a time
+SSL_WRITE_BLOCKSIZE = 16384
+
+orig_util_SSLContext = util.ssl_.SSLContext
+
+
+log = logging.getLogger(__name__)
+
+
+def inject_into_urllib3() -> None:
+    "Monkey-patch urllib3 with PyOpenSSL-backed SSL-support."
+
+    _validate_dependencies_met()
+
+    util.SSLContext = PyOpenSSLContext  # type: ignore[assignment]
+    util.ssl_.SSLContext = PyOpenSSLContext  # type: ignore[assignment]
+    util.IS_PYOPENSSL = True
+    util.ssl_.IS_PYOPENSSL = True
+
+
+def extract_from_urllib3() -> None:
+    "Undo monkey-patching by :func:`inject_into_urllib3`."
+
+    util.SSLContext = orig_util_SSLContext
+    util.ssl_.SSLContext = orig_util_SSLContext
+    util.IS_PYOPENSSL = False
+    util.ssl_.IS_PYOPENSSL = False
+
+
+def _validate_dependencies_met() -> None:
+    """
+    Verifies that PyOpenSSL's package-level dependencies have been met.
+    Throws `ImportError` if they are not met.
+    """
+    # Method added in `cryptography==1.1`; not available in older versions
+    from cryptography.x509.extensions import Extensions
+
+    if getattr(Extensions, "get_extension_for_class", None) is None:
+        raise ImportError(
+            "'cryptography' module missing required functionality.  "
+            "Try upgrading to v1.3.4 or newer."
+        )
+
+    # pyOpenSSL 0.14 and above use cryptography for OpenSSL bindings. The _x509
+    # attribute is only present on those versions.
+    from OpenSSL.crypto import X509
+
+    x509 = X509()
+    if getattr(x509, "_x509", None) is None:
+        raise ImportError(
+            "'pyOpenSSL' module missing required functionality. "
+            "Try upgrading to v0.14 or newer."
+        )
+
+
+def _dnsname_to_stdlib(name: str) -> str | None:
+    """
+    Converts a dNSName SubjectAlternativeName field to the form used by the
+    standard library on the given Python version.
+
+    Cryptography produces a dNSName as a unicode string that was idna-decoded
+    from ASCII bytes. We need to idna-encode that string to get it back, and
+    then on Python 3 we also need to convert to unicode via UTF-8 (the stdlib
+    uses PyUnicode_FromStringAndSize on it, which decodes via UTF-8).
+
+    If the name cannot be idna-encoded then we return None signalling that
+    the name given should be skipped.
+    """
+
+    def idna_encode(name: str) -> bytes | None:
+        """
+        Borrowed wholesale from the Python Cryptography Project. It turns out
+        that we can't just safely call `idna.encode`: it can explode for
+        wildcard names. This avoids that problem.
+        """
+        import idna
+
+        try:
+            for prefix in ["*.", "."]:
+                if name.startswith(prefix):
+                    name = name[len(prefix) :]
+                    return prefix.encode("ascii") + idna.encode(name)
+            return idna.encode(name)
+        except idna.core.IDNAError:
+            return None
+
+    # Don't send IPv6 addresses through the IDNA encoder.
+    if ":" in name:
+        return name
+
+    encoded_name = idna_encode(name)
+    if encoded_name is None:
+        return None
+    return encoded_name.decode("utf-8")
+
+
+def get_subj_alt_name(peer_cert: X509) -> list[tuple[str, str]]:
+    """
+    Given an PyOpenSSL certificate, provides all the subject alternative names.
+    """
+    cert = peer_cert.to_cryptography()
+
+    # We want to find the SAN extension. Ask Cryptography to locate it (it's
+    # faster than looping in Python)
+    try:
+        ext = cert.extensions.get_extension_for_class(x509.SubjectAlternativeName).value
+    except x509.ExtensionNotFound:
+        # No such extension, return the empty list.
+        return []
+    except (
+        x509.DuplicateExtension,
+        UnsupportedExtension,
+        x509.UnsupportedGeneralNameType,
+        UnicodeError,
+    ) as e:
+        # A problem has been found with the quality of the certificate. Assume
+        # no SAN field is present.
+        log.warning(
+            "A problem was encountered with the certificate that prevented "
+            "urllib3 from finding the SubjectAlternativeName field. This can "
+            "affect certificate validation. The error was %s",
+            e,
+        )
+        return []
+
+    # We want to return dNSName and iPAddress fields. We need to cast the IPs
+    # back to strings because the match_hostname function wants them as
+    # strings.
+    # Sadly the DNS names need to be idna encoded and then, on Python 3, UTF-8
+    # decoded. This is pretty frustrating, but that's what the standard library
+    # does with certificates, and so we need to attempt to do the same.
+    # We also want to skip over names which cannot be idna encoded.
+    names = [
+        ("DNS", name)
+        for name in map(_dnsname_to_stdlib, ext.get_values_for_type(x509.DNSName))
+        if name is not None
+    ]
+    names.extend(
+        ("IP Address", str(name)) for name in ext.get_values_for_type(x509.IPAddress)
+    )
+
+    return names
+
+
+class WrappedSocket:
+    """API-compatibility wrapper for Python OpenSSL's Connection-class."""
+
+    def __init__(
+        self,
+        connection: OpenSSL.SSL.Connection,
+        socket: socket_cls,
+        suppress_ragged_eofs: bool = True,
+    ) -> None:
+        self.connection = connection
+        self.socket = socket
+        self.suppress_ragged_eofs = suppress_ragged_eofs
+        self._io_refs = 0
+        self._closed = False
+
+    def fileno(self) -> int:
+        return self.socket.fileno()
+
+    # Copy-pasted from Python 3.5 source code
+    def _decref_socketios(self) -> None:
+        if self._io_refs > 0:
+            self._io_refs -= 1
+        if self._closed:
+            self.close()
+
+    def recv(self, *args: typing.Any, **kwargs: typing.Any) -> bytes:
+        try:
+            data = self.connection.recv(*args, **kwargs)
+        except OpenSSL.SSL.SysCallError as e:
+            if self.suppress_ragged_eofs and e.args == (-1, "Unexpected EOF"):
+                return b""
+            else:
+                raise OSError(e.args[0], str(e)) from e
+        except OpenSSL.SSL.ZeroReturnError:
+            if self.connection.get_shutdown() == OpenSSL.SSL.RECEIVED_SHUTDOWN:
+                return b""
+            else:
+                raise
+        except OpenSSL.SSL.WantReadError as e:
+            if not util.wait_for_read(self.socket, self.socket.gettimeout()):
+                raise timeout("The read operation timed out") from e
+            else:
+                return self.recv(*args, **kwargs)
+
+        # TLS 1.3 post-handshake authentication
+        except OpenSSL.SSL.Error as e:
+            raise ssl.SSLError(f"read error: {e!r}") from e
+        else:
+            return data  # type: ignore[no-any-return]
+
+    def recv_into(self, *args: typing.Any, **kwargs: typing.Any) -> int:
+        try:
+            return self.connection.recv_into(*args, **kwargs)  # type: ignore[no-any-return]
+        except OpenSSL.SSL.SysCallError as e:
+            if self.suppress_ragged_eofs and e.args == (-1, "Unexpected EOF"):
+                return 0
+            else:
+                raise OSError(e.args[0], str(e)) from e
+        except OpenSSL.SSL.ZeroReturnError:
+            if self.connection.get_shutdown() == OpenSSL.SSL.RECEIVED_SHUTDOWN:
+                return 0
+            else:
+                raise
+        except OpenSSL.SSL.WantReadError as e:
+            if not util.wait_for_read(self.socket, self.socket.gettimeout()):
+                raise timeout("The read operation timed out") from e
+            else:
+                return self.recv_into(*args, **kwargs)
+
+        # TLS 1.3 post-handshake authentication
+        except OpenSSL.SSL.Error as e:
+            raise ssl.SSLError(f"read error: {e!r}") from e
+
+    def settimeout(self, timeout: float) -> None:
+        return self.socket.settimeout(timeout)
+
+    def _send_until_done(self, data: bytes) -> int:
+        while True:
+            try:
+                return self.connection.send(data)  # type: ignore[no-any-return]
+            except OpenSSL.SSL.WantWriteError as e:
+                if not util.wait_for_write(self.socket, self.socket.gettimeout()):
+                    raise timeout() from e
+                continue
+            except OpenSSL.SSL.SysCallError as e:
+                raise OSError(e.args[0], str(e)) from e
+
+    def sendall(self, data: bytes) -> None:
+        total_sent = 0
+        while total_sent < len(data):
+            sent = self._send_until_done(
+                data[total_sent : total_sent + SSL_WRITE_BLOCKSIZE]
+            )
+            total_sent += sent
+
+    def shutdown(self) -> None:
+        # FIXME rethrow compatible exceptions should we ever use this
+        self.connection.shutdown()
+
+    def close(self) -> None:
+        self._closed = True
+        if self._io_refs <= 0:
+            self._real_close()
+
+    def _real_close(self) -> None:
+        try:
+            return self.connection.close()  # type: ignore[no-any-return]
+        except OpenSSL.SSL.Error:
+            return
+
+    def getpeercert(
+        self, binary_form: bool = False
+    ) -> dict[str, list[typing.Any]] | None:
+        x509 = self.connection.get_peer_certificate()
+
+        if not x509:
+            return x509  # type: ignore[no-any-return]
+
+        if binary_form:
+            return OpenSSL.crypto.dump_certificate(OpenSSL.crypto.FILETYPE_ASN1, x509)  # type: ignore[no-any-return]
+
+        return {
+            "subject": ((("commonName", x509.get_subject().CN),),),  # type: ignore[dict-item]
+            "subjectAltName": get_subj_alt_name(x509),
+        }
+
+    def version(self) -> str:
+        return self.connection.get_protocol_version_name()  # type: ignore[no-any-return]
+
+
+WrappedSocket.makefile = socket_cls.makefile  # type: ignore[attr-defined]
+
+
+class PyOpenSSLContext:
+    """
+    I am a wrapper class for the PyOpenSSL ``Context`` object. I am responsible
+    for translating the interface of the standard library ``SSLContext`` object
+    to calls into PyOpenSSL.
+    """
+
+    def __init__(self, protocol: int) -> None:
+        self.protocol = _openssl_versions[protocol]
+        self._ctx = OpenSSL.SSL.Context(self.protocol)
+        self._options = 0
+        self.check_hostname = False
+        self._minimum_version: int = ssl.TLSVersion.MINIMUM_SUPPORTED
+        self._maximum_version: int = ssl.TLSVersion.MAXIMUM_SUPPORTED
+
+    @property
+    def options(self) -> int:
+        return self._options
+
+    @options.setter
+    def options(self, value: int) -> None:
+        self._options = value
+        self._set_ctx_options()
+
+    @property
+    def verify_mode(self) -> int:
+        return _openssl_to_stdlib_verify[self._ctx.get_verify_mode()]
+
+    @verify_mode.setter
+    def verify_mode(self, value: ssl.VerifyMode) -> None:
+        self._ctx.set_verify(_stdlib_to_openssl_verify[value], _verify_callback)
+
+    def set_default_verify_paths(self) -> None:
+        self._ctx.set_default_verify_paths()
+
+    def set_ciphers(self, ciphers: bytes | str) -> None:
+        if isinstance(ciphers, str):
+            ciphers = ciphers.encode("utf-8")
+        self._ctx.set_cipher_list(ciphers)
+
+    def load_verify_locations(
+        self,
+        cafile: str | None = None,
+        capath: str | None = None,
+        cadata: bytes | None = None,
+    ) -> None:
+        if cafile is not None:
+            cafile = cafile.encode("utf-8")  # type: ignore[assignment]
+        if capath is not None:
+            capath = capath.encode("utf-8")  # type: ignore[assignment]
+        try:
+            self._ctx.load_verify_locations(cafile, capath)
+            if cadata is not None:
+                self._ctx.load_verify_locations(BytesIO(cadata))
+        except OpenSSL.SSL.Error as e:
+            raise ssl.SSLError(f"unable to load trusted certificates: {e!r}") from e
+
+    def load_cert_chain(
+        self,
+        certfile: str,
+        keyfile: str | None = None,
+        password: str | None = None,
+    ) -> None:
+        try:
+            self._ctx.use_certificate_chain_file(certfile)
+            if password is not None:
+                if not isinstance(password, bytes):
+                    password = password.encode("utf-8")  # type: ignore[assignment]
+                self._ctx.set_passwd_cb(lambda *_: password)
+            self._ctx.use_privatekey_file(keyfile or certfile)
+        except OpenSSL.SSL.Error as e:
+            raise ssl.SSLError(f"Unable to load certificate chain: {e!r}") from e
+
+    def set_alpn_protocols(self, protocols: list[bytes | str]) -> None:
+        protocols = [util.util.to_bytes(p, "ascii") for p in protocols]
+        return self._ctx.set_alpn_protos(protocols)  # type: ignore[no-any-return]
+
+    def wrap_socket(
+        self,
+        sock: socket_cls,
+        server_side: bool = False,
+        do_handshake_on_connect: bool = True,
+        suppress_ragged_eofs: bool = True,
+        server_hostname: bytes | str | None = None,
+    ) -> WrappedSocket:
+        cnx = OpenSSL.SSL.Connection(self._ctx, sock)
+
+        # If server_hostname is an IP, don't use it for SNI, per RFC6066 Section 3
+        if server_hostname and not util.ssl_.is_ipaddress(server_hostname):
+            if isinstance(server_hostname, str):
+                server_hostname = server_hostname.encode("utf-8")
+            cnx.set_tlsext_host_name(server_hostname)
+
+        cnx.set_connect_state()
+
+        while True:
+            try:
+                cnx.do_handshake()
+            except OpenSSL.SSL.WantReadError as e:
+                if not util.wait_for_read(sock, sock.gettimeout()):
+                    raise timeout("select timed out") from e
+                continue
+            except OpenSSL.SSL.Error as e:
+                raise ssl.SSLError(f"bad handshake: {e!r}") from e
+            break
+
+        return WrappedSocket(cnx, sock)
+
+    def _set_ctx_options(self) -> None:
+        self._ctx.set_options(
+            self._options
+            | _openssl_to_ssl_minimum_version[self._minimum_version]
+            | _openssl_to_ssl_maximum_version[self._maximum_version]
+        )
+
+    @property
+    def minimum_version(self) -> int:
+        return self._minimum_version
+
+    @minimum_version.setter
+    def minimum_version(self, minimum_version: int) -> None:
+        self._minimum_version = minimum_version
+        self._set_ctx_options()
+
+    @property
+    def maximum_version(self) -> int:
+        return self._maximum_version
+
+    @maximum_version.setter
+    def maximum_version(self, maximum_version: int) -> None:
+        self._maximum_version = maximum_version
+        self._set_ctx_options()
+
+
+def _verify_callback(
+    cnx: OpenSSL.SSL.Connection,
+    x509: X509,
+    err_no: int,
+    err_depth: int,
+    return_code: int,
+) -> bool:
+    return err_no == 0