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1577 lines (1317 loc) · 52.9 KB
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# Wrapper module for _ssl, providing some additional facilities
# implemented in Python. Written by Bill Janssen.
"""This module provides some more Pythonic support for SSL.
Object types:
SSLSocket -- subtype of socket.socket which does SSL over the socket
Exceptions:
SSLError -- exception raised for I/O errors
Functions:
get_sigalgs -- return a list of all available TLS signature
algorithms (requires OpenSSL 3.4 or later)
cert_time_to_seconds -- convert time string used for certificate
notBefore and notAfter functions to integer
seconds past the Epoch (the time values
returned from time.time())
get_server_certificate (addr, ssl_version, ca_certs, timeout) -- Retrieve the
certificate from the server at the specified
address and return it as a PEM-encoded string
Integer constants:
SSL_ERROR_ZERO_RETURN
SSL_ERROR_WANT_READ
SSL_ERROR_WANT_WRITE
SSL_ERROR_WANT_X509_LOOKUP
SSL_ERROR_SYSCALL
SSL_ERROR_SSL
SSL_ERROR_WANT_CONNECT
SSL_ERROR_EOF
SSL_ERROR_INVALID_ERROR_CODE
The following group define certificate requirements that one side is
allowing/requiring from the other side:
CERT_NONE - no certificates from the other side are required (or will
be looked at if provided)
CERT_OPTIONAL - certificates are not required, but if provided will be
validated, and if validation fails, the connection will
also fail
CERT_REQUIRED - certificates are required, and will be validated, and
if validation fails, the connection will also fail
The following constants identify various SSL protocol variants:
PROTOCOL_SSLv2
PROTOCOL_SSLv3
PROTOCOL_SSLv23
PROTOCOL_TLS
PROTOCOL_TLS_CLIENT
PROTOCOL_TLS_SERVER
PROTOCOL_TLSv1
PROTOCOL_TLSv1_1
PROTOCOL_TLSv1_2
The following constants identify various SSL alert message descriptions as per
http://www.iana.org/assignments/tls-parameters/tls-parameters.xml#tls-parameters-6
ALERT_DESCRIPTION_CLOSE_NOTIFY
ALERT_DESCRIPTION_UNEXPECTED_MESSAGE
ALERT_DESCRIPTION_BAD_RECORD_MAC
ALERT_DESCRIPTION_RECORD_OVERFLOW
ALERT_DESCRIPTION_DECOMPRESSION_FAILURE
ALERT_DESCRIPTION_HANDSHAKE_FAILURE
ALERT_DESCRIPTION_BAD_CERTIFICATE
ALERT_DESCRIPTION_UNSUPPORTED_CERTIFICATE
ALERT_DESCRIPTION_CERTIFICATE_REVOKED
ALERT_DESCRIPTION_CERTIFICATE_EXPIRED
ALERT_DESCRIPTION_CERTIFICATE_UNKNOWN
ALERT_DESCRIPTION_ILLEGAL_PARAMETER
ALERT_DESCRIPTION_UNKNOWN_CA
ALERT_DESCRIPTION_ACCESS_DENIED
ALERT_DESCRIPTION_DECODE_ERROR
ALERT_DESCRIPTION_DECRYPT_ERROR
ALERT_DESCRIPTION_PROTOCOL_VERSION
ALERT_DESCRIPTION_INSUFFICIENT_SECURITY
ALERT_DESCRIPTION_INTERNAL_ERROR
ALERT_DESCRIPTION_USER_CANCELLED
ALERT_DESCRIPTION_NO_RENEGOTIATION
ALERT_DESCRIPTION_UNSUPPORTED_EXTENSION
ALERT_DESCRIPTION_CERTIFICATE_UNOBTAINABLE
ALERT_DESCRIPTION_UNRECOGNIZED_NAME
ALERT_DESCRIPTION_BAD_CERTIFICATE_STATUS_RESPONSE
ALERT_DESCRIPTION_BAD_CERTIFICATE_HASH_VALUE
ALERT_DESCRIPTION_UNKNOWN_PSK_IDENTITY
"""
import sys
import os
from collections import namedtuple
from enum import Enum as _Enum, IntEnum as _IntEnum, IntFlag as _IntFlag
from enum import _simple_enum
import _ssl # if we can't import it, let the error propagate
from _ssl import OPENSSL_VERSION_NUMBER, OPENSSL_VERSION_INFO, OPENSSL_VERSION
from _ssl import _SSLContext, MemoryBIO, SSLSession
from _ssl import (
SSLError, SSLZeroReturnError, SSLWantReadError, SSLWantWriteError,
SSLSyscallError, SSLEOFError, SSLCertVerificationError
)
from _ssl import txt2obj as _txt2obj, nid2obj as _nid2obj
from _ssl import RAND_status, RAND_add, RAND_bytes
from _ssl import get_sigalgs
from _ssl import (
HAS_SNI, HAS_ECDH, HAS_NPN, HAS_ALPN, HAS_SSLv2, HAS_SSLv3, HAS_TLSv1,
HAS_TLSv1_1, HAS_TLSv1_2, HAS_TLSv1_3, HAS_PSK, HAS_PSK_TLS13, HAS_PHA
)
from _ssl import _DEFAULT_CIPHERS, _OPENSSL_API_VERSION
_IntEnum._convert_(
'_SSLMethod', __name__,
lambda name: name.startswith('PROTOCOL_') and name != 'PROTOCOL_SSLv23',
source=_ssl)
_IntFlag._convert_(
'Options', __name__,
lambda name: name.startswith('OP_'),
source=_ssl)
_IntEnum._convert_(
'AlertDescription', __name__,
lambda name: name.startswith('ALERT_DESCRIPTION_'),
source=_ssl)
_IntEnum._convert_(
'SSLErrorNumber', __name__,
lambda name: name.startswith('SSL_ERROR_'),
source=_ssl)
_IntFlag._convert_(
'VerifyFlags', __name__,
lambda name: name.startswith('VERIFY_'),
source=_ssl)
_IntEnum._convert_(
'VerifyMode', __name__,
lambda name: name.startswith('CERT_'),
source=_ssl)
PROTOCOL_SSLv23 = _SSLMethod.PROTOCOL_SSLv23 = _SSLMethod.PROTOCOL_TLS
_PROTOCOL_NAMES = frozendict({
value: name for name, value in _SSLMethod.__members__.items()})
_SSLv2_IF_EXISTS = getattr(_SSLMethod, 'PROTOCOL_SSLv2', None)
@_simple_enum(_IntEnum)
class TLSVersion:
MINIMUM_SUPPORTED = _ssl.PROTO_MINIMUM_SUPPORTED
SSLv3 = _ssl.PROTO_SSLv3
TLSv1 = _ssl.PROTO_TLSv1
TLSv1_1 = _ssl.PROTO_TLSv1_1
TLSv1_2 = _ssl.PROTO_TLSv1_2
TLSv1_3 = _ssl.PROTO_TLSv1_3
MAXIMUM_SUPPORTED = _ssl.PROTO_MAXIMUM_SUPPORTED
@_simple_enum(_IntEnum)
class _TLSContentType:
"""Content types (record layer)
See RFC 8446, section B.1
"""
CHANGE_CIPHER_SPEC = 20
ALERT = 21
HANDSHAKE = 22
APPLICATION_DATA = 23
# pseudo content types
HEADER = 0x100
INNER_CONTENT_TYPE = 0x101
@_simple_enum(_IntEnum)
class _TLSAlertType:
"""Alert types for TLSContentType.ALERT messages
See RFC 8446, section B.2
"""
CLOSE_NOTIFY = 0
UNEXPECTED_MESSAGE = 10
BAD_RECORD_MAC = 20
DECRYPTION_FAILED = 21
RECORD_OVERFLOW = 22
DECOMPRESSION_FAILURE = 30
HANDSHAKE_FAILURE = 40
NO_CERTIFICATE = 41
BAD_CERTIFICATE = 42
UNSUPPORTED_CERTIFICATE = 43
CERTIFICATE_REVOKED = 44
CERTIFICATE_EXPIRED = 45
CERTIFICATE_UNKNOWN = 46
ILLEGAL_PARAMETER = 47
UNKNOWN_CA = 48
ACCESS_DENIED = 49
DECODE_ERROR = 50
DECRYPT_ERROR = 51
EXPORT_RESTRICTION = 60
PROTOCOL_VERSION = 70
INSUFFICIENT_SECURITY = 71
INTERNAL_ERROR = 80
INAPPROPRIATE_FALLBACK = 86
USER_CANCELED = 90
NO_RENEGOTIATION = 100
MISSING_EXTENSION = 109
UNSUPPORTED_EXTENSION = 110
CERTIFICATE_UNOBTAINABLE = 111
UNRECOGNIZED_NAME = 112
BAD_CERTIFICATE_STATUS_RESPONSE = 113
BAD_CERTIFICATE_HASH_VALUE = 114
UNKNOWN_PSK_IDENTITY = 115
CERTIFICATE_REQUIRED = 116
NO_APPLICATION_PROTOCOL = 120
@_simple_enum(_IntEnum)
class _TLSMessageType:
"""Message types (handshake protocol)
See RFC 8446, section B.3
"""
HELLO_REQUEST = 0
CLIENT_HELLO = 1
SERVER_HELLO = 2
HELLO_VERIFY_REQUEST = 3
NEWSESSION_TICKET = 4
END_OF_EARLY_DATA = 5
HELLO_RETRY_REQUEST = 6
ENCRYPTED_EXTENSIONS = 8
CERTIFICATE = 11
SERVER_KEY_EXCHANGE = 12
CERTIFICATE_REQUEST = 13
SERVER_DONE = 14
CERTIFICATE_VERIFY = 15
CLIENT_KEY_EXCHANGE = 16
FINISHED = 20
CERTIFICATE_URL = 21
CERTIFICATE_STATUS = 22
SUPPLEMENTAL_DATA = 23
KEY_UPDATE = 24
NEXT_PROTO = 67
MESSAGE_HASH = 254
CHANGE_CIPHER_SPEC = 0x0101
if sys.platform == "win32":
from _ssl import enum_certificates, enum_crls
from socket import socket, SOCK_STREAM, create_connection
from socket import SOL_SOCKET, SO_TYPE, _GLOBAL_DEFAULT_TIMEOUT
import socket as _socket
import base64 # for DER-to-PEM translation
import errno
import warnings
socket_error = OSError # keep that public name in module namespace
CHANNEL_BINDING_TYPES = ['tls-unique']
HAS_NEVER_CHECK_COMMON_NAME = hasattr(_ssl, 'HOSTFLAG_NEVER_CHECK_SUBJECT')
_RESTRICTED_SERVER_CIPHERS = _DEFAULT_CIPHERS
CertificateError = SSLCertVerificationError
def _dnsname_match(dn, hostname):
"""Matching according to RFC 6125, section 6.4.3
- Hostnames are compared lower-case.
- For IDNA, both dn and hostname must be encoded as IDN A-label (ACE).
- Partial wildcards like 'www*.example.org', multiple wildcards, sole
wildcard or wildcards in labels other then the left-most label are not
supported and a CertificateError is raised.
- A wildcard must match at least one character.
"""
if not dn:
return False
wildcards = dn.count('*')
# speed up common case w/o wildcards
if not wildcards:
return dn.lower() == hostname.lower()
if wildcards > 1:
raise CertificateError(
"too many wildcards in certificate DNS name: {!r}.".format(dn))
dn_leftmost, sep, dn_remainder = dn.partition('.')
if '*' in dn_remainder:
# Only match wildcard in leftmost segment.
raise CertificateError(
"wildcard can only be present in the leftmost label: "
"{!r}.".format(dn))
if not sep:
# no right side
raise CertificateError(
"sole wildcard without additional labels are not support: "
"{!r}.".format(dn))
if dn_leftmost != '*':
# no partial wildcard matching
raise CertificateError(
"partial wildcards in leftmost label are not supported: "
"{!r}.".format(dn))
hostname_leftmost, sep, hostname_remainder = hostname.partition('.')
if not hostname_leftmost or not sep:
# wildcard must match at least one char
return False
return dn_remainder.lower() == hostname_remainder.lower()
def _inet_paton(ipname):
"""Try to convert an IP address to packed binary form
Supports IPv4 addresses on all platforms and IPv6 on platforms with IPv6
support.
"""
# inet_aton() also accepts strings like '1', '127.1', some also trailing
# data like '127.0.0.1 whatever'.
try:
addr = _socket.inet_aton(ipname)
except OSError:
# not an IPv4 address
pass
else:
if _socket.inet_ntoa(addr) == ipname:
# only accept injective ipnames
return addr
else:
# refuse for short IPv4 notation and additional trailing data
raise ValueError(
"{!r} is not a quad-dotted IPv4 address.".format(ipname)
)
try:
return _socket.inet_pton(_socket.AF_INET6, ipname)
except OSError:
raise ValueError("{!r} is neither an IPv4 nor an IP6 "
"address.".format(ipname))
except AttributeError:
# AF_INET6 not available
pass
raise ValueError("{!r} is not an IPv4 address.".format(ipname))
def _ipaddress_match(cert_ipaddress, host_ip):
"""Exact matching of IP addresses.
RFC 6125 explicitly doesn't define an algorithm for this
(section 1.7.2 - "Out of Scope").
"""
# OpenSSL may add a trailing newline to a subjectAltName's IP address,
# commonly with IPv6 addresses. Strip off trailing \n.
ip = _inet_paton(cert_ipaddress.rstrip())
return ip == host_ip
DefaultVerifyPaths = namedtuple("DefaultVerifyPaths",
"cafile capath openssl_cafile_env openssl_cafile openssl_capath_env "
"openssl_capath")
def get_default_verify_paths():
"""Return paths to default cafile and capath.
"""
parts = _ssl.get_default_verify_paths()
# environment vars shadow paths
cafile = os.environ.get(parts[0], parts[1])
capath = os.environ.get(parts[2], parts[3])
return DefaultVerifyPaths(cafile if os.path.isfile(cafile) else None,
capath if os.path.isdir(capath) else None,
*parts)
class _ASN1Object(namedtuple("_ASN1Object", "nid shortname longname oid")):
"""ASN.1 object identifier lookup
"""
__slots__ = ()
def __new__(cls, oid):
return super().__new__(cls, *_txt2obj(oid, name=False))
@classmethod
def fromnid(cls, nid):
"""Create _ASN1Object from OpenSSL numeric ID
"""
return super().__new__(cls, *_nid2obj(nid))
@classmethod
def fromname(cls, name):
"""Create _ASN1Object from short name, long name or OID
"""
return super().__new__(cls, *_txt2obj(name, name=True))
class Purpose(_ASN1Object, _Enum):
"""SSLContext purpose flags with X509v3 Extended Key Usage objects
"""
SERVER_AUTH = '1.3.6.1.5.5.7.3.1'
CLIENT_AUTH = '1.3.6.1.5.5.7.3.2'
class SSLContext(_SSLContext):
"""An SSLContext holds various SSL-related configuration options and
data, such as certificates and possibly a private key."""
_windows_cert_stores = ("CA", "ROOT")
sslsocket_class = None # SSLSocket is assigned later.
sslobject_class = None # SSLObject is assigned later.
def __new__(cls, protocol=None, *args, **kwargs):
if protocol is None:
warnings.warn(
"ssl.SSLContext() without protocol argument is deprecated.",
category=DeprecationWarning,
stacklevel=2
)
protocol = PROTOCOL_TLS
self = _SSLContext.__new__(cls, protocol)
return self
def _encode_hostname(self, hostname):
if hostname is None:
return None
elif isinstance(hostname, str):
return hostname.encode('idna').decode('ascii')
else:
return hostname.decode('ascii')
def wrap_socket(self, sock, server_side=False,
do_handshake_on_connect=True,
suppress_ragged_eofs=True,
server_hostname=None, session=None):
# SSLSocket class handles server_hostname encoding before it calls
# ctx._wrap_socket()
return self.sslsocket_class._create(
sock=sock,
server_side=server_side,
do_handshake_on_connect=do_handshake_on_connect,
suppress_ragged_eofs=suppress_ragged_eofs,
server_hostname=server_hostname,
context=self,
session=session
)
def wrap_bio(self, incoming, outgoing, server_side=False,
server_hostname=None, session=None):
# Need to encode server_hostname here because _wrap_bio() can only
# handle ASCII str.
return self.sslobject_class._create(
incoming, outgoing, server_side=server_side,
server_hostname=self._encode_hostname(server_hostname),
session=session, context=self,
)
def set_npn_protocols(self, npn_protocols):
warnings.warn(
"ssl NPN is deprecated, use ALPN instead",
DeprecationWarning,
stacklevel=2
)
protos = bytearray()
for protocol in npn_protocols:
b = bytes(protocol, 'ascii')
if len(b) == 0 or len(b) > 255:
raise SSLError('NPN protocols must be 1 to 255 in length')
protos.append(len(b))
protos.extend(b)
self._set_npn_protocols(protos)
def set_servername_callback(self, server_name_callback):
if server_name_callback is None:
self.sni_callback = None
else:
if not callable(server_name_callback):
raise TypeError("not a callable object")
def shim_cb(sslobj, servername, sslctx):
servername = self._encode_hostname(servername)
return server_name_callback(sslobj, servername, sslctx)
self.sni_callback = shim_cb
def set_alpn_protocols(self, alpn_protocols):
protos = bytearray()
for protocol in alpn_protocols:
b = bytes(protocol, 'ascii')
if len(b) == 0 or len(b) > 255:
raise SSLError('ALPN protocols must be 1 to 255 in length')
protos.append(len(b))
protos.extend(b)
self._set_alpn_protocols(protos)
def _load_windows_store_certs(self, storename, purpose):
try:
for cert, encoding, trust in enum_certificates(storename):
# CA certs are never PKCS#7 encoded
if encoding == "x509_asn":
if trust is True or purpose.oid in trust:
try:
self.load_verify_locations(cadata=cert)
except SSLError as exc:
warnings.warn(f"Bad certificate in Windows certificate store: {exc!s}")
except PermissionError:
warnings.warn("unable to enumerate Windows certificate store")
def load_default_certs(self, purpose=Purpose.SERVER_AUTH):
if not isinstance(purpose, _ASN1Object):
raise TypeError(purpose)
if sys.platform == "win32":
for storename in self._windows_cert_stores:
self._load_windows_store_certs(storename, purpose)
self.set_default_verify_paths()
if hasattr(_SSLContext, 'minimum_version'):
@property
def minimum_version(self):
return TLSVersion(super().minimum_version)
@minimum_version.setter
def minimum_version(self, value):
if value == TLSVersion.SSLv3:
self.options &= ~Options.OP_NO_SSLv3
super(SSLContext, SSLContext).minimum_version.__set__(self, value)
@property
def maximum_version(self):
return TLSVersion(super().maximum_version)
@maximum_version.setter
def maximum_version(self, value):
super(SSLContext, SSLContext).maximum_version.__set__(self, value)
@property
def options(self):
return Options(super().options)
@options.setter
def options(self, value):
super(SSLContext, SSLContext).options.__set__(self, value)
if hasattr(_ssl, 'HOSTFLAG_NEVER_CHECK_SUBJECT'):
@property
def hostname_checks_common_name(self):
ncs = self._host_flags & _ssl.HOSTFLAG_NEVER_CHECK_SUBJECT
return ncs != _ssl.HOSTFLAG_NEVER_CHECK_SUBJECT
@hostname_checks_common_name.setter
def hostname_checks_common_name(self, value):
if value:
self._host_flags &= ~_ssl.HOSTFLAG_NEVER_CHECK_SUBJECT
else:
self._host_flags |= _ssl.HOSTFLAG_NEVER_CHECK_SUBJECT
else:
@property
def hostname_checks_common_name(self):
return True
@property
def _msg_callback(self):
"""TLS message callback
The message callback provides a debugging hook to analyze TLS
connections. The callback is called for any TLS protocol message
(header, handshake, alert, and more), but not for application data.
Due to technical limitations, the callback can't be used to filter
traffic or to abort a connection. Any exception raised in the
callback is delayed until the handshake, read, or write operation
has been performed.
def msg_cb(conn, direction, version, content_type, msg_type, data):
pass
conn
:class:`SSLSocket` or :class:`SSLObject` instance
direction
``read`` or ``write``
version
:class:`TLSVersion` enum member or int for unknown version. For a
frame header, it's the header version.
content_type
:class:`_TLSContentType` enum member or int for unsupported
content type.
msg_type
Either a :class:`_TLSContentType` enum number for a header
message, a :class:`_TLSAlertType` enum member for an alert
message, a :class:`_TLSMessageType` enum member for other
messages, or int for unsupported message types.
data
Raw, decrypted message content as bytes
"""
inner = super()._msg_callback
if inner is not None:
return inner.user_function
else:
return None
@_msg_callback.setter
def _msg_callback(self, callback):
if callback is None:
super(SSLContext, SSLContext)._msg_callback.__set__(self, None)
return
if not hasattr(callback, '__call__'):
raise TypeError(f"{callback} is not callable.")
def inner(conn, direction, version, content_type, msg_type, data):
try:
version = TLSVersion(version)
except ValueError:
pass
try:
content_type = _TLSContentType(content_type)
except ValueError:
pass
if content_type == _TLSContentType.HEADER:
msg_enum = _TLSContentType
elif content_type == _TLSContentType.ALERT:
msg_enum = _TLSAlertType
else:
msg_enum = _TLSMessageType
try:
msg_type = msg_enum(msg_type)
except ValueError:
pass
return callback(conn, direction, version,
content_type, msg_type, data)
inner.user_function = callback
super(SSLContext, SSLContext)._msg_callback.__set__(self, inner)
@property
def protocol(self):
return _SSLMethod(super().protocol)
@property
def verify_flags(self):
return VerifyFlags(super().verify_flags)
@verify_flags.setter
def verify_flags(self, value):
super(SSLContext, SSLContext).verify_flags.__set__(self, value)
@property
def verify_mode(self):
value = super().verify_mode
try:
return VerifyMode(value)
except ValueError:
return value
@verify_mode.setter
def verify_mode(self, value):
super(SSLContext, SSLContext).verify_mode.__set__(self, value)
def create_default_context(purpose=Purpose.SERVER_AUTH, *, cafile=None,
capath=None, cadata=None):
"""Create a SSLContext object with default settings.
NOTE: The protocol and settings may change anytime without prior
deprecation. The values represent a fair balance between maximum
compatibility and security.
"""
if not isinstance(purpose, _ASN1Object):
raise TypeError(purpose)
# SSLContext sets OP_NO_SSLv2, OP_NO_SSLv3, OP_NO_COMPRESSION,
# OP_CIPHER_SERVER_PREFERENCE, OP_SINGLE_DH_USE and OP_SINGLE_ECDH_USE
# by default.
if purpose == Purpose.SERVER_AUTH:
# verify certs and host name in client mode
context = SSLContext(PROTOCOL_TLS_CLIENT)
context.verify_mode = CERT_REQUIRED
context.check_hostname = True
elif purpose == Purpose.CLIENT_AUTH:
context = SSLContext(PROTOCOL_TLS_SERVER)
else:
raise ValueError(purpose)
# `VERIFY_X509_PARTIAL_CHAIN` makes OpenSSL's chain building behave more
# like RFC 3280 and 5280, which specify that chain building stops with the
# first trust anchor, even if that anchor is not self-signed.
#
# `VERIFY_X509_STRICT` makes OpenSSL more conservative about the
# certificates it accepts, including "disabling workarounds for
# some broken certificates."
context.verify_flags |= (_ssl.VERIFY_X509_PARTIAL_CHAIN |
_ssl.VERIFY_X509_STRICT)
if cafile or capath or cadata:
context.load_verify_locations(cafile, capath, cadata)
elif context.verify_mode != CERT_NONE:
# no explicit cafile, capath or cadata but the verify mode is
# CERT_OPTIONAL or CERT_REQUIRED. Let's try to load default system
# root CA certificates for the given purpose. This may fail silently.
context.load_default_certs(purpose)
# OpenSSL 1.1.1 keylog file
if hasattr(context, 'keylog_filename'):
keylogfile = os.environ.get('SSLKEYLOGFILE')
if keylogfile and not sys.flags.ignore_environment:
context.keylog_filename = keylogfile
return context
def _create_unverified_context(protocol=None, *, cert_reqs=CERT_NONE,
check_hostname=False, purpose=Purpose.SERVER_AUTH,
certfile=None, keyfile=None,
cafile=None, capath=None, cadata=None):
"""Create a SSLContext object for Python stdlib modules
All Python stdlib modules shall use this function to create SSLContext
objects in order to keep common settings in one place. The configuration
is less restrict than create_default_context()'s to increase backward
compatibility.
"""
if not isinstance(purpose, _ASN1Object):
raise TypeError(purpose)
# SSLContext sets OP_NO_SSLv2, OP_NO_SSLv3, OP_NO_COMPRESSION,
# OP_CIPHER_SERVER_PREFERENCE, OP_SINGLE_DH_USE and OP_SINGLE_ECDH_USE
# by default.
if purpose == Purpose.SERVER_AUTH:
# verify certs and host name in client mode
if protocol is None:
protocol = PROTOCOL_TLS_CLIENT
elif purpose == Purpose.CLIENT_AUTH:
if protocol is None:
protocol = PROTOCOL_TLS_SERVER
else:
raise ValueError(purpose)
context = SSLContext(protocol)
context.check_hostname = check_hostname
if cert_reqs is not None:
context.verify_mode = cert_reqs
if check_hostname:
context.check_hostname = True
if keyfile and not certfile:
raise ValueError("certfile must be specified")
if certfile or keyfile:
context.load_cert_chain(certfile, keyfile)
# load CA root certs
if cafile or capath or cadata:
context.load_verify_locations(cafile, capath, cadata)
elif context.verify_mode != CERT_NONE:
# no explicit cafile, capath or cadata but the verify mode is
# CERT_OPTIONAL or CERT_REQUIRED. Let's try to load default system
# root CA certificates for the given purpose. This may fail silently.
context.load_default_certs(purpose)
# OpenSSL 1.1.1 keylog file
if hasattr(context, 'keylog_filename'):
keylogfile = os.environ.get('SSLKEYLOGFILE')
if keylogfile and not sys.flags.ignore_environment:
context.keylog_filename = keylogfile
return context
# Used by http.client if no context is explicitly passed.
_create_default_https_context = create_default_context
# Backwards compatibility alias, even though it's not a public name.
_create_stdlib_context = _create_unverified_context
class SSLObject:
"""This class implements an interface on top of a low-level SSL object as
implemented by OpenSSL. This object captures the state of an SSL connection
but does not provide any network IO itself. IO needs to be performed
through separate "BIO" objects which are OpenSSL's IO abstraction layer.
This class does not have a public constructor. Instances are returned by
``SSLContext.wrap_bio``. This class is typically used by framework authors
that want to implement asynchronous IO for SSL through memory buffers.
When compared to ``SSLSocket``, this object lacks the following features:
* Any form of network IO, including methods such as ``recv`` and ``send``.
* The ``do_handshake_on_connect`` and ``suppress_ragged_eofs`` machinery.
"""
def __init__(self, *args, **kwargs):
raise TypeError(
f"{self.__class__.__name__} does not have a public "
f"constructor. Instances are returned by SSLContext.wrap_bio()."
)
@classmethod
def _create(cls, incoming, outgoing, server_side=False,
server_hostname=None, session=None, context=None):
self = cls.__new__(cls)
sslobj = context._wrap_bio(
incoming, outgoing, server_side=server_side,
server_hostname=server_hostname,
owner=self, session=session
)
self._sslobj = sslobj
return self
@property
def context(self):
"""The SSLContext that is currently in use."""
return self._sslobj.context
@context.setter
def context(self, ctx):
self._sslobj.context = ctx
@property
def session(self):
"""The SSLSession for client socket."""
return self._sslobj.session
@session.setter
def session(self, session):
self._sslobj.session = session
@property
def session_reused(self):
"""Was the client session reused during handshake"""
return self._sslobj.session_reused
@property
def server_side(self):
"""Whether this is a server-side socket."""
return self._sslobj.server_side
@property
def server_hostname(self):
"""The currently set server hostname (for SNI), or ``None`` if no
server hostname is set."""
return self._sslobj.server_hostname
def read(self, len=1024, buffer=None):
"""Read up to 'len' bytes from the SSL object and return them.
If 'buffer' is provided, read into this buffer and return the number of
bytes read.
"""
if buffer is not None:
v = self._sslobj.read(len, buffer)
else:
v = self._sslobj.read(len)
return v
def write(self, data):
"""Write 'data' to the SSL object and return the number of bytes
written.
The 'data' argument must support the buffer interface.
"""
return self._sslobj.write(data)
def getpeercert(self, binary_form=False):
"""Returns a formatted version of the data in the certificate provided
by the other end of the SSL channel.
Return None if no certificate was provided, {} if a certificate was
provided, but not validated.
"""
return self._sslobj.getpeercert(binary_form)
def get_verified_chain(self):
"""Returns verified certificate chain provided by the other
end of the SSL channel as a list of DER-encoded bytes.
If certificate verification was disabled method acts the same as
``SSLSocket.get_unverified_chain``.
"""
chain = self._sslobj.get_verified_chain()
if chain is None:
return []
return [cert.public_bytes(_ssl.ENCODING_DER) for cert in chain]
def get_unverified_chain(self):
"""Returns raw certificate chain provided by the other
end of the SSL channel as a list of DER-encoded bytes.
"""
chain = self._sslobj.get_unverified_chain()
if chain is None:
return []
return [cert.public_bytes(_ssl.ENCODING_DER) for cert in chain]
def selected_npn_protocol(self):
"""Return the currently selected NPN protocol as a string, or ``None``
if a next protocol was not negotiated or if NPN is not supported by one
of the peers."""
warnings.warn(
"ssl NPN is deprecated, use ALPN instead",
DeprecationWarning,
stacklevel=2
)
def selected_alpn_protocol(self):
"""Return the currently selected ALPN protocol as a string, or ``None``
if a next protocol was not negotiated or if ALPN is not supported by one
of the peers."""
return self._sslobj.selected_alpn_protocol()
def cipher(self):
"""Return the currently selected cipher as a 3-tuple ``(name,
ssl_version, secret_bits)``."""
return self._sslobj.cipher()
def group(self):
"""Return the currently selected key agreement group name."""
return self._sslobj.group()
def client_sigalg(self):
"""Return the selected client authentication signature algorithm."""
return self._sslobj.client_sigalg()
def server_sigalg(self):
"""Return the selected server handshake signature algorithm."""
return self._sslobj.server_sigalg()
def shared_ciphers(self):
"""Return a list of ciphers shared by the client during the handshake or
None if this is not a valid server connection.
"""
return self._sslobj.shared_ciphers()
def compression(self):
"""Return the current compression algorithm in use, or ``None`` if
compression was not negotiated or not supported by one of the peers."""
return self._sslobj.compression()
def pending(self):
"""Return the number of bytes that can be read immediately."""
return self._sslobj.pending()
def do_handshake(self):
"""Start the SSL/TLS handshake."""
self._sslobj.do_handshake()
def unwrap(self):
"""Start the SSL shutdown handshake."""
return self._sslobj.shutdown()
def get_channel_binding(self, cb_type="tls-unique"):
"""Get channel binding data for current connection. Raise ValueError
if the requested `cb_type` is not supported. Return bytes of the data
or None if the data is not available (e.g. before the handshake)."""
return self._sslobj.get_channel_binding(cb_type)
def version(self):
"""Return a string identifying the protocol version used by the
current SSL channel. """
return self._sslobj.version()
def verify_client_post_handshake(self):
return self._sslobj.verify_client_post_handshake()
def _sslcopydoc(func):
"""Copy docstring from SSLObject to SSLSocket"""
func.__doc__ = getattr(SSLObject, func.__name__).__doc__
return func
class _GiveupOnSSLSendfile(Exception):
pass
class SSLSocket(socket):
"""This class implements a subtype of socket.socket that wraps
the underlying OS socket in an SSL context when necessary, and
provides read and write methods over that channel. """
def __init__(self, *args, **kwargs):
raise TypeError(