from __future__ import annotations import hmac import os import socket import sys import typing import warnings from binascii import unhexlify from hashlib import md5, sha1, sha256 from ..exceptions import ProxySchemeUnsupported, SSLError from .url import _BRACELESS_IPV6_ADDRZ_RE, _IPV4_RE SSLContext = None SSLTransport = None HAS_NEVER_CHECK_COMMON_NAME = False IS_PYOPENSSL = False IS_SECURETRANSPORT = False ALPN_PROTOCOLS = ["http/1.1"] _TYPE_VERSION_INFO = typing.Tuple[int, int, int, str, int] # Maps the length of a digest to a possible hash function producing this digest HASHFUNC_MAP = {32: md5, 40: sha1, 64: sha256} def _is_bpo_43522_fixed( implementation_name: str, version_info: _TYPE_VERSION_INFO ) -> bool: """Return True for CPython 3.8.9+, 3.9.3+ or 3.10+ where setting SSLContext.hostname_checks_common_name to False works. PyPy 7.3.7 doesn't work as it doesn't ship with OpenSSL 1.1.1l+ so we're waiting for a version of PyPy that works before allowing this function to return 'True'. Outside of CPython and PyPy we don't know which implementations work or not so we conservatively use our hostname matching as we know that works on all implementations. https://github.com/urllib3/urllib3/issues/2192#issuecomment-821832963 https://foss.heptapod.net/pypy/pypy/-/issues/3539# """ if implementation_name != "cpython": return False major_minor = version_info[:2] micro = version_info[2] return ( (major_minor == (3, 8) and micro >= 9) or (major_minor == (3, 9) and micro >= 3) or major_minor >= (3, 10) ) def _is_has_never_check_common_name_reliable( openssl_version: str, openssl_version_number: int, implementation_name: str, version_info: _TYPE_VERSION_INFO, ) -> bool: # As of May 2023, all released versions of LibreSSL fail to reject certificates with # only common names, see https://github.com/urllib3/urllib3/pull/3024 is_openssl = openssl_version.startswith("OpenSSL ") # Before fixing OpenSSL issue #14579, the SSL_new() API was not copying hostflags # like X509_CHECK_FLAG_NEVER_CHECK_SUBJECT, which tripped up CPython. # https://github.com/openssl/openssl/issues/14579 # This was released in OpenSSL 1.1.1l+ (>=0x101010cf) is_openssl_issue_14579_fixed = openssl_version_number >= 0x101010CF return is_openssl and ( is_openssl_issue_14579_fixed or _is_bpo_43522_fixed(implementation_name, version_info) ) if typing.TYPE_CHECKING: from ssl import VerifyMode from typing_extensions import Literal, TypedDict from .ssltransport import SSLTransport as SSLTransportType class _TYPE_PEER_CERT_RET_DICT(TypedDict, total=False): subjectAltName: tuple[tuple[str, str], ...] subject: tuple[tuple[tuple[str, str], ...], ...] serialNumber: str # Mapping from 'ssl.PROTOCOL_TLSX' to 'TLSVersion.X' _SSL_VERSION_TO_TLS_VERSION: dict[int, int] = {} try: # Do we have ssl at all? import ssl from ssl import ( # type: ignore[assignment] CERT_REQUIRED, HAS_NEVER_CHECK_COMMON_NAME, OP_NO_COMPRESSION, OP_NO_TICKET, OPENSSL_VERSION, OPENSSL_VERSION_NUMBER, PROTOCOL_TLS, PROTOCOL_TLS_CLIENT, OP_NO_SSLv2, OP_NO_SSLv3, SSLContext, TLSVersion, ) PROTOCOL_SSLv23 = PROTOCOL_TLS # Setting SSLContext.hostname_checks_common_name = False didn't work before CPython # 3.8.9, 3.9.3, and 3.10 (but OK on PyPy) or OpenSSL 1.1.1l+ if HAS_NEVER_CHECK_COMMON_NAME and not _is_has_never_check_common_name_reliable( OPENSSL_VERSION, OPENSSL_VERSION_NUMBER, sys.implementation.name, sys.version_info, ): HAS_NEVER_CHECK_COMMON_NAME = False # Need to be careful here in case old TLS versions get # removed in future 'ssl' module implementations. for attr in ("TLSv1", "TLSv1_1", "TLSv1_2"): try: _SSL_VERSION_TO_TLS_VERSION[getattr(ssl, f"PROTOCOL_{attr}")] = getattr( TLSVersion, attr ) except AttributeError: # Defensive: continue from .ssltransport import SSLTransport # type: ignore[assignment] except ImportError: OP_NO_COMPRESSION = 0x20000 # type: ignore[assignment] OP_NO_TICKET = 0x4000 # type: ignore[assignment] OP_NO_SSLv2 = 0x1000000 # type: ignore[assignment] OP_NO_SSLv3 = 0x2000000 # type: ignore[assignment] PROTOCOL_SSLv23 = PROTOCOL_TLS = 2 # type: ignore[assignment] PROTOCOL_TLS_CLIENT = 16 # type: ignore[assignment] _TYPE_PEER_CERT_RET = typing.Union["_TYPE_PEER_CERT_RET_DICT", bytes, None] def assert_fingerprint(cert: bytes | None, fingerprint: str) -> None: """ Checks if given fingerprint matches the supplied certificate. :param cert: Certificate as bytes object. :param fingerprint: Fingerprint as string of hexdigits, can be interspersed by colons. """ if cert is None: raise SSLError("No certificate for the peer.") fingerprint = fingerprint.replace(":", "").lower() digest_length = len(fingerprint) hashfunc = HASHFUNC_MAP.get(digest_length) if not hashfunc: raise SSLError(f"Fingerprint of invalid length: {fingerprint}") # We need encode() here for py32; works on py2 and p33. fingerprint_bytes = unhexlify(fingerprint.encode()) cert_digest = hashfunc(cert).digest() if not hmac.compare_digest(cert_digest, fingerprint_bytes): raise SSLError( f'Fingerprints did not match. Expected "{fingerprint}", got "{cert_digest.hex()}"' ) def resolve_cert_reqs(candidate: None | int | str) -> VerifyMode: """ Resolves the argument to a numeric constant, which can be passed to the wrap_socket function/method from the ssl module. Defaults to :data:`ssl.CERT_REQUIRED`. If given a string it is assumed to be the name of the constant in the :mod:`ssl` module or its abbreviation. (So you can specify `REQUIRED` instead of `CERT_REQUIRED`. If it's neither `None` nor a string we assume it is already the numeric constant which can directly be passed to wrap_socket. """ if candidate is None: return CERT_REQUIRED if isinstance(candidate, str): res = getattr(ssl, candidate, None) if res is None: res = getattr(ssl, "CERT_" + candidate) return res # type: ignore[no-any-return] return candidate # type: ignore[return-value] def resolve_ssl_version(candidate: None | int | str) -> int: """ like resolve_cert_reqs """ if candidate is None: return PROTOCOL_TLS if isinstance(candidate, str): res = getattr(ssl, candidate, None) if res is None: res = getattr(ssl, "PROTOCOL_" + candidate) return typing.cast(int, res) return candidate def create_urllib3_context( ssl_version: int | None = None, cert_reqs: int | None = None, options: int | None = None, ciphers: str | None = None, ssl_minimum_version: int | None = None, ssl_maximum_version: int | None = None, ) -> ssl.SSLContext: """Creates and configures an :class:`ssl.SSLContext` instance for use with urllib3. :param ssl_version: The desired protocol version to use. This will default to PROTOCOL_SSLv23 which will negotiate the highest protocol that both the server and your installation of OpenSSL support. This parameter is deprecated instead use 'ssl_minimum_version'. :param ssl_minimum_version: The minimum version of TLS to be used. Use the 'ssl.TLSVersion' enum for specifying the value. :param ssl_maximum_version: The maximum version of TLS to be used. Use the 'ssl.TLSVersion' enum for specifying the value. Not recommended to set to anything other than 'ssl.TLSVersion.MAXIMUM_SUPPORTED' which is the default value. :param cert_reqs: Whether to require the certificate verification. This defaults to ``ssl.CERT_REQUIRED``. :param options: Specific OpenSSL options. These default to ``ssl.OP_NO_SSLv2``, ``ssl.OP_NO_SSLv3``, ``ssl.OP_NO_COMPRESSION``, and ``ssl.OP_NO_TICKET``. :param ciphers: Which cipher suites to allow the server to select. Defaults to either system configured ciphers if OpenSSL 1.1.1+, otherwise uses a secure default set of ciphers. :returns: Constructed SSLContext object with specified options :rtype: SSLContext """ if SSLContext is None: raise TypeError("Can't create an SSLContext object without an ssl module") # This means 'ssl_version' was specified as an exact value. if ssl_version not in (None, PROTOCOL_TLS, PROTOCOL_TLS_CLIENT): # Disallow setting 'ssl_version' and 'ssl_minimum|maximum_version' # to avoid conflicts. if ssl_minimum_version is not None or ssl_maximum_version is not None: raise ValueError( "Can't specify both 'ssl_version' and either " "'ssl_minimum_version' or 'ssl_maximum_version'" ) # 'ssl_version' is deprecated and will be removed in the future. else: # Use 'ssl_minimum_version' and 'ssl_maximum_version' instead. ssl_minimum_version = _SSL_VERSION_TO_TLS_VERSION.get( ssl_version, TLSVersion.MINIMUM_SUPPORTED ) ssl_maximum_version = _SSL_VERSION_TO_TLS_VERSION.get( ssl_version, TLSVersion.MAXIMUM_SUPPORTED ) # This warning message is pushing users to use 'ssl_minimum_version' # instead of both min/max. Best practice is to only set the minimum version and # keep the maximum version to be it's default value: 'TLSVersion.MAXIMUM_SUPPORTED' warnings.warn( "'ssl_version' option is deprecated and will be " "removed in urllib3 v2.1.0. Instead use 'ssl_minimum_version'", category=DeprecationWarning, stacklevel=2, ) # PROTOCOL_TLS is deprecated in Python 3.10 so we always use PROTOCOL_TLS_CLIENT context = SSLContext(PROTOCOL_TLS_CLIENT) if ssl_minimum_version is not None: context.minimum_version = ssl_minimum_version else: # Python <3.10 defaults to 'MINIMUM_SUPPORTED' so explicitly set TLSv1.2 here context.minimum_version = TLSVersion.TLSv1_2 if ssl_maximum_version is not None: context.maximum_version = ssl_maximum_version # Unless we're given ciphers defer to either system ciphers in # the case of OpenSSL 1.1.1+ or use our own secure default ciphers. if ciphers: context.set_ciphers(ciphers) # Setting the default here, as we may have no ssl module on import cert_reqs = ssl.CERT_REQUIRED if cert_reqs is None else cert_reqs if options is None: options = 0 # SSLv2 is easily broken and is considered harmful and dangerous options |= OP_NO_SSLv2 # SSLv3 has several problems and is now dangerous options |= OP_NO_SSLv3 # Disable compression to prevent CRIME attacks for OpenSSL 1.0+ # (issue #309) options |= OP_NO_COMPRESSION # TLSv1.2 only. Unless set explicitly, do not request tickets. # This may save some bandwidth on wire, and although the ticket is encrypted, # there is a risk associated with it being on wire, # if the server is not rotating its ticketing keys properly. options |= OP_NO_TICKET context.options |= options # Enable post-handshake authentication for TLS 1.3, see GH #1634. PHA is # necessary for conditional client cert authentication with TLS 1.3. # The attribute is None for OpenSSL <= 1.1.0 or does not exist in older # versions of Python. We only enable on Python 3.7.4+ or if certificate # verification is enabled to work around Python issue #37428 # See: https://bugs.python.org/issue37428 if (cert_reqs == ssl.CERT_REQUIRED or sys.version_info >= (3, 7, 4)) and getattr( context, "post_handshake_auth", None ) is not None: context.post_handshake_auth = True # The order of the below lines setting verify_mode and check_hostname # matter due to safe-guards SSLContext has to prevent an SSLContext with # check_hostname=True, verify_mode=NONE/OPTIONAL. # We always set 'check_hostname=False' for pyOpenSSL so we rely on our own # 'ssl.match_hostname()' implementation. if cert_reqs == ssl.CERT_REQUIRED and not IS_PYOPENSSL: context.verify_mode = cert_reqs context.check_hostname = True else: context.check_hostname = False context.verify_mode = cert_reqs try: context.hostname_checks_common_name = False except AttributeError: pass # Enable logging of TLS session keys via defacto standard environment variable # 'SSLKEYLOGFILE', if the feature is available (Python 3.8+). Skip empty values. if hasattr(context, "keylog_filename"): sslkeylogfile = os.environ.get("SSLKEYLOGFILE") if sslkeylogfile: context.keylog_filename = sslkeylogfile return context @typing.overload def ssl_wrap_socket( sock: socket.socket, keyfile: str | None = ..., certfile: str | None = ..., cert_reqs: int | None = ..., ca_certs: str | None = ..., server_hostname: str | None = ..., ssl_version: int | None = ..., ciphers: str | None = ..., ssl_context: ssl.SSLContext | None = ..., ca_cert_dir: str | None = ..., key_password: str | None = ..., ca_cert_data: None | str | bytes = ..., tls_in_tls: Literal[False] = ..., ) -> ssl.SSLSocket: ... @typing.overload def ssl_wrap_socket( sock: socket.socket, keyfile: str | None = ..., certfile: str | None = ..., cert_reqs: int | None = ..., ca_certs: str | None = ..., server_hostname: str | None = ..., ssl_version: int | None = ..., ciphers: str | None = ..., ssl_context: ssl.SSLContext | None = ..., ca_cert_dir: str | None = ..., key_password: str | None = ..., ca_cert_data: None | str | bytes = ..., tls_in_tls: bool = ..., ) -> ssl.SSLSocket | SSLTransportType: ... def ssl_wrap_socket( sock: socket.socket, keyfile: str | None = None, certfile: str | None = None, cert_reqs: int | None = None, ca_certs: str | None = None, server_hostname: str | None = None, ssl_version: int | None = None, ciphers: str | None = None, ssl_context: ssl.SSLContext | None = None, ca_cert_dir: str | None = None, key_password: str | None = None, ca_cert_data: None | str | bytes = None, tls_in_tls: bool = False, ) -> ssl.SSLSocket | SSLTransportType: """ All arguments except for server_hostname, ssl_context, and ca_cert_dir have the same meaning as they do when using :func:`ssl.wrap_socket`. :param server_hostname: When SNI is supported, the expected hostname of the certificate :param ssl_context: A pre-made :class:`SSLContext` object. If none is provided, one will be created using :func:`create_urllib3_context`. :param ciphers: A string of ciphers we wish the client to support. :param ca_cert_dir: A directory containing CA certificates in multiple separate files, as supported by OpenSSL's -CApath flag or the capath argument to SSLContext.load_verify_locations(). :param key_password: Optional password if the keyfile is encrypted. :param ca_cert_data: Optional string containing CA certificates in PEM format suitable for passing as the cadata parameter to SSLContext.load_verify_locations() :param tls_in_tls: Use SSLTransport to wrap the existing socket. """ context = ssl_context if context is None: # Note: This branch of code and all the variables in it are only used in tests. # We should consider deprecating and removing this code. context = create_urllib3_context(ssl_version, cert_reqs, ciphers=ciphers) if ca_certs or ca_cert_dir or ca_cert_data: try: context.load_verify_locations(ca_certs, ca_cert_dir, ca_cert_data) except OSError as e: raise SSLError(e) from e elif ssl_context is None and hasattr(context, "load_default_certs"): # try to load OS default certs; works well on Windows. context.load_default_certs() # Attempt to detect if we get the goofy behavior of the # keyfile being encrypted and OpenSSL asking for the # passphrase via the terminal and instead error out. if keyfile and key_password is None and _is_key_file_encrypted(keyfile): raise SSLError("Client private key is encrypted, password is required") if certfile: if key_password is None: context.load_cert_chain(certfile, keyfile) else: context.load_cert_chain(certfile, keyfile, key_password) try: context.set_alpn_protocols(ALPN_PROTOCOLS) except NotImplementedError: # Defensive: in CI, we always have set_alpn_protocols pass ssl_sock = _ssl_wrap_socket_impl(sock, context, tls_in_tls, server_hostname) return ssl_sock def is_ipaddress(hostname: str | bytes) -> bool: """Detects whether the hostname given is an IPv4 or IPv6 address. Also detects IPv6 addresses with Zone IDs. :param str hostname: Hostname to examine. :return: True if the hostname is an IP address, False otherwise. """ if isinstance(hostname, bytes): # IDN A-label bytes are ASCII compatible. hostname = hostname.decode("ascii") return bool(_IPV4_RE.match(hostname) or _BRACELESS_IPV6_ADDRZ_RE.match(hostname)) def _is_key_file_encrypted(key_file: str) -> bool: """Detects if a key file is encrypted or not.""" with open(key_file) as f: for line in f: # Look for Proc-Type: 4,ENCRYPTED if "ENCRYPTED" in line: return True return False def _ssl_wrap_socket_impl( sock: socket.socket, ssl_context: ssl.SSLContext, tls_in_tls: bool, server_hostname: str | None = None, ) -> ssl.SSLSocket | SSLTransportType: if tls_in_tls: if not SSLTransport: # Import error, ssl is not available. raise ProxySchemeUnsupported( "TLS in TLS requires support for the 'ssl' module" ) SSLTransport._validate_ssl_context_for_tls_in_tls(ssl_context) return SSLTransport(sock, ssl_context, server_hostname) return ssl_context.wrap_socket(sock, server_hostname=server_hostname)