"""
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, from cryptography)
However, pyOpenSSL depends on cryptography, which depends on idna, 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]
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
import warnings
from io import BytesIO
from socket import socket as socket_cls
from socket import timeout
from .. import util
warnings.warn(
"'urllib3.contrib.pyopenssl' module is deprecated and will be removed "
"in urllib3 v2.1.0. Read more in this issue: "
"https://github.com/urllib3/urllib3/issues/2680",
category=DeprecationWarning,
stacklevel=2,
)
if typing.TYPE_CHECKING:
from OpenSSL.crypto import X509 # type: ignore[import]
__all__ = ["inject_into_urllib3", "extract_from_urllib3"]
# Map from urllib3 to PyOpenSSL compatible parameter-values.
_openssl_versions = {
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__)
[docs]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 _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