Source code for gevent.ssl

# Wrapper module for _ssl. Written by Bill Janssen.
# Ported to gevent by Denis Bilenko.
"""SSL wrapper for socket objects on Python 3.

For the documentation, refer to :mod:`ssl` module manual.

This module implements cooperative SSL socket wrappers.

from __future__ import absolute_import
import ssl as __ssl__

_ssl = __ssl__._ssl

import errno

from gevent.socket import socket, timeout_default
from gevent.socket import error as socket_error
from gevent.socket import timeout as _socket_timeout
from gevent._util import copy_globals

from weakref import ref as _wref

__implements__ = [

if hasattr(__ssl__, 'wrap_socket'):
    __extra__ = []
    __extra__ = [

# Manually import things we use so we get better linting.
# Also, in the past (adding 3.9 support) it turned out we were
# relying on certain global variables being defined in the ssl module
# that weren't required to be there, e.g., AF_INET, which should be imported
# from socket
from socket import AF_INET
from socket import SOCK_STREAM
from socket import SO_TYPE
from socket import SOL_SOCKET

from ssl import SSLWantReadError
from ssl import SSLWantWriteError
from ssl import SSLEOFError
from ssl import CERT_NONE
from ssl import SSLError
from ssl import SSL_ERROR_EOF
from ssl import SSL_ERROR_WANT_READ
from ssl import SSL_ERROR_WANT_WRITE
from ssl import PROTOCOL_SSLv23
#from ssl import SSLObject

from ssl import CERT_REQUIRED
from ssl import DER_cert_to_PEM_cert
from ssl import create_connection

# Import all symbols from Python's, except those that we are implementing
# and "private" symbols.
__imports__ = copy_globals(
    __ssl__, globals(),
    # SSLSocket *must* subclass gevent.socket.socket; see issue 597
    names_to_ignore=__implements__ + ['socket'],

__all__ = __implements__ + __imports__ + __extra__
if 'namedtuple' in __all__:

orig_SSLContext = __ssl__.SSLContext # pylint:disable=no-member

# We have to pass the raw stdlib socket to SSLContext.wrap_socket.
# That method in turn can pass that object on to things like SNI callbacks.
# It wouldn't have access to any of the attributes on the SSLSocket, like
# context, that it's supposed to (see test_ssl.test_sni_callback). Previously
# we just delegated to the sslsocket with __getattr__, but 3.8
# added some new callbacks and a test that the object they get is an instance
# of the high-level SSLSocket class, so that doesn't work anymore. Instead,
# we wrap the callback and get the real socket to pass on.
class _contextawaresock(socket._gevent_sock_class):
    __slots__ = ('_sslsock',)

    def __init__(self, family, type, proto, fileno, sslsocket_wref):
        super().__init__(family, type, proto, fileno)
        self._sslsock = sslsocket_wref

class _Callback(object):

    __slots__ = ('user_function',)

    def __init__(self, user_function):
        self.user_function = user_function

    def __call__(self, conn, *args):
        conn = conn._sslsock()
        return self.user_function(conn, *args)

[docs] class SSLContext(orig_SSLContext): __slots__ = () # Added in Python 3.7 sslsocket_class = None # SSLSocket is assigned later def wrap_socket(self, sock, server_side=False, do_handshake_on_connect=True, suppress_ragged_eofs=True, server_hostname=None, session=None): # pylint:disable=arguments-differ,not-callable # (3.6 adds session) # Sadly, using *args and **kwargs doesn't work return self.sslsocket_class( 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) if hasattr(orig_SSLContext.options, 'setter'): # In 3.6, these became properties. They want to access the # property __set__ method in the superclass, and they do so by using # super(SSLContext, SSLContext). But we rebind SSLContext when we monkey # patch, which causes infinite recursion. # # pylint:disable=no-member @orig_SSLContext.options.setter def options(self, value): super(orig_SSLContext, orig_SSLContext).options.__set__(self, value) @orig_SSLContext.verify_flags.setter def verify_flags(self, value): super(orig_SSLContext, orig_SSLContext).verify_flags.__set__(self, value) @orig_SSLContext.verify_mode.setter def verify_mode(self, value): super(orig_SSLContext, orig_SSLContext).verify_mode.__set__(self, value) if hasattr(orig_SSLContext, 'minimum_version'): # Like the above, added in 3.7 # pylint:disable=no-member @orig_SSLContext.minimum_version.setter def minimum_version(self, value): super(orig_SSLContext, orig_SSLContext).minimum_version.__set__(self, value) @orig_SSLContext.maximum_version.setter def maximum_version(self, value): super(orig_SSLContext, orig_SSLContext).maximum_version.__set__(self, value) if hasattr(orig_SSLContext, '_msg_callback'): # And ditto for 3.8 # msg_callback is more complex because they want to actually *do* stuff # in the setter, so we need to call it. For that to work we temporarily rebind # SSLContext back. This function cannot switch, so it should be safe, # unless somehow we have multiple threads in a monkey-patched ssl module # at the same time, which doesn't make much sense. @property def _msg_callback(self): result = super()._msg_callback if isinstance(result, _Callback): result = result.user_function return result @_msg_callback.setter def _msg_callback(self, value): if value and callable(value): value = _Callback(value) __ssl__.SSLContext = orig_SSLContext try: super(SSLContext, SSLContext)._msg_callback.__set__(self, value) # pylint:disable=no-member finally: __ssl__.SSLContext = SSLContext if hasattr(orig_SSLContext, 'sni_callback'): # Added in 3.7. @property def sni_callback(self): result = super().sni_callback if isinstance(result, _Callback): result = result.user_function # pylint:disable=no-member return result @sni_callback.setter def sni_callback(self, value): if value and callable(value): value = _Callback(value) super(orig_SSLContext, orig_SSLContext).sni_callback.__set__(self, value) # pylint:disable=no-member else: # In newer versions, this just sets sni_callback. def set_servername_callback(self, server_name_callback): if server_name_callback and callable(server_name_callback): server_name_callback = _Callback(server_name_callback) super().set_servername_callback(server_name_callback)
[docs] class SSLSocket(socket): """ gevent `ssl.SSLSocket <>`_ for Python 3. """ # pylint:disable=too-many-instance-attributes,too-many-public-methods def __init__(self, sock=None, keyfile=None, certfile=None, server_side=False, cert_reqs=CERT_NONE, ssl_version=PROTOCOL_SSLv23, ca_certs=None, do_handshake_on_connect=True, family=AF_INET, type=SOCK_STREAM, proto=0, fileno=None, suppress_ragged_eofs=True, npn_protocols=None, ciphers=None, server_hostname=None, _session=None, # 3.6 _context=None): # When a *sock* argument is passed, it is used only for its fileno() # and is immediately detach()'d *unless* we raise an error. # pylint:disable=too-many-locals,too-many-statements,too-many-branches if _context: self._context = _context else: if server_side and not certfile: raise ValueError("certfile must be specified for server-side " "operations") if keyfile and not certfile: raise ValueError("certfile must be specified") if certfile and not keyfile: keyfile = certfile self._context = SSLContext(ssl_version) self._context.verify_mode = cert_reqs if ca_certs: self._context.load_verify_locations(ca_certs) if certfile: self._context.load_cert_chain(certfile, keyfile) if npn_protocols: self._context.set_npn_protocols(npn_protocols) if ciphers: self._context.set_ciphers(ciphers) self.keyfile = keyfile self.certfile = certfile self.cert_reqs = cert_reqs self.ssl_version = ssl_version self.ca_certs = ca_certs self.ciphers = ciphers # Can't use sock.type as other flags (such as SOCK_NONBLOCK) get # mixed in. if sock.getsockopt(SOL_SOCKET, SO_TYPE) != SOCK_STREAM: raise NotImplementedError("only stream sockets are supported") if server_side: if server_hostname: raise ValueError("server_hostname can only be specified " "in client mode") if _session is not None: raise ValueError("session can only be specified " "in client mode") if self._context.check_hostname and not server_hostname: raise ValueError("check_hostname requires server_hostname") self._session = _session self.server_side = server_side self.server_hostname = server_hostname self.do_handshake_on_connect = do_handshake_on_connect self.suppress_ragged_eofs = suppress_ragged_eofs connected = False if sock is not None: timeout = sock.gettimeout() socket.__init__(self,, type=sock.type, proto=sock.proto, fileno=sock.fileno()) self.settimeout(timeout) # When Python 3 sockets are __del__, they close() themselves, # including their underlying fd, unless they have been detached. # Only detach if we succeed in taking ownership; if we raise an exception, # then the user might have no way to close us and release the resources. sock.detach() elif fileno is not None: socket.__init__(self, fileno=fileno) else: socket.__init__(self, family=family, type=type, proto=proto) self._closed = False self._sslobj = None # see if we're connected try: self._sock.getpeername() except socket_error as e: if e.errno != errno.ENOTCONN: # This file descriptor is hosed, shared or not. # Clean up. self.close() raise else: connected = True self._connected = connected if connected: # create the SSL object try: self._sslobj = self.__create_sslobj(server_side, _session) if do_handshake_on_connect: timeout = self.gettimeout() if timeout == 0.0: # non-blocking raise ValueError("do_handshake_on_connect should not be specified for non-blocking sockets") self.do_handshake() except socket_error as x: self.close() raise x def _gevent_sock_class(self, family, type, proto, fileno): return _contextawaresock(family, type, proto, fileno, _wref(self)) def _extra_repr(self): return ' server=%s, cipher=%r' % ( self.server_side, self._sslobj.cipher() if self._sslobj is not None else '' ) @property def context(self): return self._context @context.setter def context(self, ctx): self._context = ctx self._sslobj.context = ctx @property def session(self): """The SSLSession for client socket.""" if self._sslobj is not None: return self._sslobj.session @session.setter def session(self, session): self._session = session if self._sslobj is not None: self._sslobj.session = session @property def session_reused(self): """Was the client session reused during handshake""" if self._sslobj is not None: return self._sslobj.session_reused
[docs] def dup(self): raise NotImplementedError("Can't dup() %s instances" % self.__class__.__name__)
def _checkClosed(self, msg=None): # raise an exception here if you wish to check for spurious closes pass def _check_connected(self): if not self._connected: # getpeername() will raise ENOTCONN if the socket is really # not connected; note that we can be connected even without # _connected being set, e.g. if connect() first returned # EAGAIN. self.getpeername()
[docs] def read(self, nbytes=2014, buffer=None): """Read up to LEN bytes and return them. Return zero-length string on EOF.""" # pylint:disable=too-many-branches self._checkClosed() # The stdlib signature is (len=1024, buffer=None) # but that shadows the len builtin, and its hard/annoying to # get it back. initial_buf_len = len(buffer) if buffer is not None else None while True: if not self._sslobj: raise ValueError("Read on closed or unwrapped SSL socket.") if nbytes == 0: return b'' if buffer is None else 0 # Negative lengths are handled natively when the buffer is None # to raise a ValueError try: if buffer is not None: return, buffer) return or 1024) except SSLWantReadError: if self.timeout == 0.0: raise self._wait(self._read_event, timeout_exc=_SSLErrorReadTimeout) except SSLWantWriteError: if self.timeout == 0.0: raise # note: using _SSLErrorReadTimeout rather than _SSLErrorWriteTimeout below is intentional self._wait(self._write_event, timeout_exc=_SSLErrorReadTimeout) except SSLError as ex: if ex.args[0] == SSL_ERROR_EOF and self.suppress_ragged_eofs: return b'' if buffer is None else len(buffer) - initial_buf_len raise
# Certain versions of Python, built against certain # versions of OpenSSL operating in certain modes, can # produce ``ConnectionResetError`` instead of # ``SSLError``. Notably, it looks like anything built # against 1.1.1c does that? gevent briefly (from support of TLS 1.3 # in Sept 2019 to issue #1637 it June 2020) caught that error and treaded # it just like SSL_ERROR_EOF. But that's not what the standard library does. # So presumably errors that result from unexpected ``ConnectionResetError`` # are issues in gevent tests.
[docs] def write(self, data): """Write DATA to the underlying SSL channel. Returns number of bytes of DATA actually transmitted.""" self._checkClosed() while True: if not self._sslobj: raise ValueError("Write on closed or unwrapped SSL socket.") try: return self._sslobj.write(data) except SSLError as ex: if ex.args[0] == SSL_ERROR_WANT_READ: if self.timeout == 0.0: raise self._wait(self._read_event, timeout_exc=_SSLErrorWriteTimeout) elif ex.args[0] == SSL_ERROR_WANT_WRITE: if self.timeout == 0.0: raise self._wait(self._write_event, timeout_exc=_SSLErrorWriteTimeout) else: raise
[docs] 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.""" self._checkClosed() self._check_connected() try: c = self._sslobj.peer_certificate except AttributeError: # 3.6 c = self._sslobj.getpeercert return c(binary_form)
def selected_npn_protocol(self): self._checkClosed() if not self._sslobj or not _ssl.HAS_NPN: return None return self._sslobj.selected_npn_protocol() if hasattr(_ssl, 'HAS_ALPN'): # 3.5+ def selected_alpn_protocol(self): self._checkClosed() if not self._sslobj or not _ssl.HAS_ALPN: # pylint:disable=no-member return None return self._sslobj.selected_alpn_protocol()
[docs] 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()
[docs] def version(self): """Return a string identifying the protocol version used by the current SSL channel. """ if not self._sslobj: return None return self._sslobj.version()
# We inherit sendfile from super(); it always uses `send` def cipher(self): self._checkClosed() if not self._sslobj: return None return self._sslobj.cipher() def compression(self): self._checkClosed() if not self._sslobj: return None return self._sslobj.compression()
[docs] def send(self, data, flags=0, timeout=timeout_default): self._checkClosed() if timeout is timeout_default: timeout = self.timeout if self._sslobj: if flags != 0: raise ValueError( "non-zero flags not allowed in calls to send() on %s" % self.__class__) while True: try: return self._sslobj.write(data) except SSLWantReadError: if self.timeout == 0.0: return 0 self._wait(self._read_event) except SSLWantWriteError: if self.timeout == 0.0: return 0 self._wait(self._write_event) else: return socket.send(self, data, flags, timeout)
[docs] def sendto(self, data, flags_or_addr, addr=None): self._checkClosed() if self._sslobj: raise ValueError("sendto not allowed on instances of %s" % self.__class__) if addr is None: return socket.sendto(self, data, flags_or_addr) return socket.sendto(self, data, flags_or_addr, addr)
def sendmsg(self, *args, **kwargs): # Ensure programs don't send data unencrypted if they try to # use this method. raise NotImplementedError("sendmsg not allowed on instances of %s" % self.__class__)
[docs] def sendall(self, data, flags=0): self._checkClosed() if self._sslobj: if flags != 0: raise ValueError( "non-zero flags not allowed in calls to sendall() on %s" % self.__class__) try: return socket.sendall(self, data, flags) except _socket_timeout: if self.timeout == 0.0: # Raised by the stdlib on non-blocking sockets raise SSLWantWriteError("The operation did not complete (write)") raise
[docs] def recv(self, buflen=1024, flags=0): self._checkClosed() if self._sslobj: if flags != 0: raise ValueError( "non-zero flags not allowed in calls to recv() on %s" % self.__class__) if buflen == 0: # # Python #23804 return b'' return return socket.recv(self, buflen, flags)
[docs] def recv_into(self, buffer, nbytes=None, flags=0): self._checkClosed() if buffer and (nbytes is None): nbytes = len(buffer) elif nbytes is None: nbytes = 1024 if self._sslobj: if flags != 0: raise ValueError("non-zero flags not allowed in calls to recv_into() on %s" % self.__class__) return, buffer) return socket.recv_into(self, buffer, nbytes, flags)
[docs] def recvfrom(self, buflen=1024, flags=0): self._checkClosed() if self._sslobj: raise ValueError("recvfrom not allowed on instances of %s" % self.__class__) return socket.recvfrom(self, buflen, flags)
[docs] def recvfrom_into(self, buffer, nbytes=None, flags=0): self._checkClosed() if self._sslobj: raise ValueError("recvfrom_into not allowed on instances of %s" % self.__class__) return socket.recvfrom_into(self, buffer, nbytes, flags)
def recvmsg(self, *args, **kwargs): raise NotImplementedError("recvmsg not allowed on instances of %s" % self.__class__) def recvmsg_into(self, *args, **kwargs): raise NotImplementedError("recvmsg_into not allowed on instances of " "%s" % self.__class__) def pending(self): self._checkClosed() if self._sslobj: return self._sslobj.pending() return 0
[docs] def shutdown(self, how): self._checkClosed() self._sslobj = None socket.shutdown(self, how)
def unwrap(self): if not self._sslobj: raise ValueError("No SSL wrapper around " + str(self)) try: # 3.7 and newer, that use the SSLSocket object # call its shutdown. shutdown = self._sslobj.shutdown except AttributeError: # Earlier versions use SSLObject, which covers # that with a layer. shutdown = self._sslobj.unwrap s = self._sock while True: try: s = shutdown() break except SSLWantReadError: # Callers of this method expect to get a socket # back, so we can't simply return 0, we have # to let these be raised if self.timeout == 0.0: raise self._wait(self._read_event) except SSLWantWriteError: if self.timeout == 0.0: raise self._wait(self._write_event) except SSLEOFError: break except OSError as e: if e.errno == 0: # The equivalent of SSLEOFError on unpatched versions of Python. # break raise self._sslobj = None # The return value of shutting down the SSLObject is the # original wrapped socket passed to _wrap_socket, i.e., # _contextawaresock. But that object doesn't have the # gevent wrapper around it so it can't be used. We have to # wrap it back up with a gevent wrapper. assert s is self._sock # In the stdlib, SSLSocket subclasses socket.socket and passes itself # to _wrap_socket, so it gets itself back. We can't do that, we have to # pass our subclass of _socket.socket, _contextawaresock. # So ultimately we should return ourself. # See return self def _real_close(self): self._sslobj = None socket._real_close(self)
[docs] def do_handshake(self): """Perform a TLS/SSL handshake.""" self._check_connected() while True: try: self._sslobj.do_handshake() break except SSLWantReadError: if self.timeout == 0.0: raise self._wait(self._read_event, timeout_exc=_SSLErrorHandshakeTimeout) except SSLWantWriteError: if self.timeout == 0.0: raise self._wait(self._write_event, timeout_exc=_SSLErrorHandshakeTimeout)
# 3.7+, making it difficult to create these objects. # There's a new type, _ssl.SSLSocket, that takes the # place of SSLObject for self._sslobj. This one does it all. def __create_sslobj(self, server_side=False, session=None): return self.context._wrap_socket( self._sock, server_side, self.server_hostname, owner=self._sock, session=session ) def _real_connect(self, addr, connect_ex): if self.server_side: raise ValueError("can't connect in server-side mode") # Here we assume that the socket is client-side, and not # connected at the time of the call. We connect it, then wrap it. if self._connected: raise ValueError("attempt to connect already-connected SSLSocket!") self._sslobj = self.__create_sslobj(False, self._session) try: if connect_ex: rc = socket.connect_ex(self, addr) else: rc = None socket.connect(self, addr) if not rc: if self.do_handshake_on_connect: self.do_handshake() self._connected = True return rc except socket_error: self._sslobj = None raise
[docs] def connect(self, addr): """Connects to remote ADDR, and then wraps the connection in an SSL channel.""" self._real_connect(addr, False)
[docs] def connect_ex(self, addr): """Connects to remote ADDR, and then wraps the connection in an SSL channel.""" return self._real_connect(addr, True)
[docs] def accept(self): """ Accepts a new connection from a remote client, and returns a tuple containing that new connection wrapped with a server-side SSL channel, and the address of the remote client. """ newsock, addr = super().accept() try: newsock = self._context.wrap_socket( newsock, do_handshake_on_connect=self.do_handshake_on_connect, suppress_ragged_eofs=self.suppress_ragged_eofs, server_side=True ) return newsock, addr except: newsock.close() raise
[docs] 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). """ if hasattr(self._sslobj, 'get_channel_binding'): # 3.7+, and sslobj is not None return self._sslobj.get_channel_binding(cb_type) if cb_type not in CHANNEL_BINDING_TYPES: raise ValueError("Unsupported channel binding type") if cb_type != "tls-unique": raise NotImplementedError("{0} channel binding type not implemented".format(cb_type)) if self._sslobj is None: return None return self._sslobj.tls_unique_cb()
def verify_client_post_handshake(self): # Only present in 3.7.1+; an attributeerror is alright if self._sslobj: return self._sslobj.verify_client_post_handshake() raise ValueError("No SSL wrapper around " + str(self))
# Python does not support forward declaration of types SSLContext.sslsocket_class = SSLSocket # Python 3.2 onwards raise normal timeout errors, not SSLError. # See _SSLErrorReadTimeout = _socket_timeout('The read operation timed out') _SSLErrorWriteTimeout = _socket_timeout('The write operation timed out') _SSLErrorHandshakeTimeout = _socket_timeout('The handshake operation timed out') def wrap_socket(sock, keyfile=None, certfile=None, server_side=False, cert_reqs=CERT_NONE, ssl_version=PROTOCOL_SSLv23, ca_certs=None, do_handshake_on_connect=True, suppress_ragged_eofs=True, ciphers=None): return SSLSocket(sock=sock, keyfile=keyfile, certfile=certfile, server_side=server_side, cert_reqs=cert_reqs, ssl_version=ssl_version, ca_certs=ca_certs, do_handshake_on_connect=do_handshake_on_connect, suppress_ragged_eofs=suppress_ragged_eofs, ciphers=ciphers)
[docs] def get_server_certificate(addr, ssl_version=PROTOCOL_SSLv23, ca_certs=None): """Retrieve the certificate from the server at the specified address, and return it as a PEM-encoded string. If 'ca_certs' is specified, validate the server cert against it. If 'ssl_version' is specified, use it in the connection attempt.""" _, _ = addr if ca_certs is not None: cert_reqs = CERT_REQUIRED else: cert_reqs = CERT_NONE with create_connection(addr) as sock: with wrap_socket(sock, ssl_version=ssl_version, cert_reqs=cert_reqs, ca_certs=ca_certs) as sslsock: dercert = sslsock.getpeercert(True) sslsock = sock = None return DER_cert_to_PEM_cert(dercert)