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Python

# Wrapper module for _ssl. Written by Bill Janssen.
# Ported to gevent by Denis Bilenko.
"""
SSL wrapper for socket objects on Python 2.7.8 and below.
For the documentation, refer to :mod:`ssl` module manual.
This module implements cooperative SSL socket wrappers.
.. deprecated:: 1.3
This module is not secure. Support for Python versions
with only this level of SSL will be dropped in gevent 1.4.
"""
from __future__ import absolute_import
# Our import magic sadly makes this warning useless
# pylint: disable=undefined-variable,arguments-differ,no-member
import ssl as __ssl__
_ssl = __ssl__._ssl
import sys
import errno
from gevent._socket2 import socket
from gevent.socket import _fileobject, timeout_default
from gevent.socket import error as socket_error, EWOULDBLOCK
from gevent.socket import timeout as _socket_timeout
from gevent._compat import PYPY
from gevent._util import copy_globals
__implements__ = [
'SSLSocket',
'wrap_socket',
'get_server_certificate',
'sslwrap_simple',
]
# Import all symbols from Python's ssl.py, 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'],
dunder_names_to_keep=())
# Py2.6 can get RAND_status added twice
__all__ = list(set(__implements__) | set(__imports__))
if 'namedtuple' in __all__:
__all__.remove('namedtuple')
class SSLSocket(socket):
"""
gevent `ssl.SSLSocket <https://docs.python.org/2.6/library/ssl.html#sslsocket-objects>`_
for Pythons < 2.7.9.
"""
def __init__(self, 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):
socket.__init__(self, _sock=sock)
if PYPY:
sock._drop()
if certfile and not keyfile:
keyfile = certfile
# see if it's connected
try:
socket.getpeername(self)
except socket_error as e:
if e.args[0] != errno.ENOTCONN:
raise
# no, no connection yet
self._sslobj = None
else:
# yes, create the SSL object
if ciphers is None:
self._sslobj = _ssl.sslwrap(self._sock, server_side,
keyfile, certfile,
cert_reqs, ssl_version, ca_certs)
else:
self._sslobj = _ssl.sslwrap(self._sock, server_side,
keyfile, certfile,
cert_reqs, ssl_version, ca_certs,
ciphers)
if do_handshake_on_connect:
self.do_handshake()
self.keyfile = keyfile
self.certfile = certfile
self.cert_reqs = cert_reqs
self.ssl_version = ssl_version
self.ca_certs = ca_certs
self.ciphers = ciphers
self.do_handshake_on_connect = do_handshake_on_connect
self.suppress_ragged_eofs = suppress_ragged_eofs
self._makefile_refs = 0
def read(self, len=1024):
"""Read up to LEN bytes and return them.
Return zero-length string on EOF."""
while True:
try:
return self._sslobj.read(len)
except SSLError as ex:
if ex.args[0] == SSL_ERROR_EOF and self.suppress_ragged_eofs:
return ''
if ex.args[0] == SSL_ERROR_WANT_READ:
if self.timeout == 0.0:
raise
sys.exc_clear()
self._wait(self._read_event, timeout_exc=_SSLErrorReadTimeout)
elif ex.args[0] == SSL_ERROR_WANT_WRITE:
if self.timeout == 0.0:
raise
sys.exc_clear()
# note: using _SSLErrorReadTimeout rather than _SSLErrorWriteTimeout below is intentional
self._wait(self._write_event, timeout_exc=_SSLErrorReadTimeout)
else:
raise
def write(self, data):
"""Write DATA to the underlying SSL channel. Returns
number of bytes of DATA actually transmitted."""
while True:
try:
return self._sslobj.write(data)
except SSLError as ex:
if ex.args[0] == SSL_ERROR_WANT_READ:
if self.timeout == 0.0:
raise
sys.exc_clear()
self._wait(self._read_event, timeout_exc=_SSLErrorWriteTimeout)
elif ex.args[0] == SSL_ERROR_WANT_WRITE:
if self.timeout == 0.0:
raise
sys.exc_clear()
self._wait(self._write_event, timeout_exc=_SSLErrorWriteTimeout)
else:
raise
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.peer_certificate(binary_form)
def cipher(self):
if not self._sslobj:
return None
return self._sslobj.cipher()
def send(self, data, flags=0, timeout=timeout_default):
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:
v = self._sslobj.write(data)
except SSLError as x:
if x.args[0] == SSL_ERROR_WANT_READ:
if self.timeout == 0.0:
return 0
sys.exc_clear()
self._wait(self._read_event)
elif x.args[0] == SSL_ERROR_WANT_WRITE:
if self.timeout == 0.0:
return 0
sys.exc_clear()
self._wait(self._write_event)
else:
raise
else:
return v
else:
return socket.send(self, data, flags, timeout)
# is it possible for sendall() to send some data without encryption if another end shut down SSL?
def sendall(self, data, flags=0):
try:
socket.sendall(self, data)
except _socket_timeout as ex:
if self.timeout == 0.0:
# Python 2 simply *hangs* in this case, which is bad, but
# Python 3 raises SSLWantWriteError. We do the same.
raise SSLError(SSL_ERROR_WANT_WRITE)
# Convert the socket.timeout back to the sslerror
raise SSLError(*ex.args)
def sendto(self, *args):
if self._sslobj:
raise ValueError("sendto not allowed on instances of %s" %
self.__class__)
return socket.sendto(self, *args)
def recv(self, buflen=1024, flags=0):
if self._sslobj:
if flags != 0:
raise ValueError(
"non-zero flags not allowed in calls to recv() on %s" %
self.__class__)
# QQQ Shouldn't we wrap the SSL_WANT_READ errors as socket.timeout errors to match socket.recv's behavior?
return self.read(buflen)
return socket.recv(self, buflen, flags)
def recv_into(self, buffer, nbytes=None, flags=0):
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__)
while True:
try:
tmp_buffer = self.read(nbytes)
v = len(tmp_buffer)
buffer[:v] = tmp_buffer
return v
except SSLError as x:
if x.args[0] == SSL_ERROR_WANT_READ:
if self.timeout == 0.0:
raise
sys.exc_clear()
self._wait(self._read_event)
continue
raise
else:
return socket.recv_into(self, buffer, nbytes, flags)
def recvfrom(self, *args):
if self._sslobj:
raise ValueError("recvfrom not allowed on instances of %s" %
self.__class__)
return socket.recvfrom(self, *args)
def recvfrom_into(self, *args):
if self._sslobj:
raise ValueError("recvfrom_into not allowed on instances of %s" %
self.__class__)
return socket.recvfrom_into(self, *args)
def pending(self):
if self._sslobj:
return self._sslobj.pending()
return 0
def _sslobj_shutdown(self):
while True:
try:
return self._sslobj.shutdown()
except SSLError as ex:
if ex.args[0] == SSL_ERROR_EOF and self.suppress_ragged_eofs:
return ''
if ex.args[0] == SSL_ERROR_WANT_READ:
if self.timeout == 0.0:
raise
sys.exc_clear()
self._wait(self._read_event, timeout_exc=_SSLErrorReadTimeout)
elif ex.args[0] == SSL_ERROR_WANT_WRITE:
if self.timeout == 0.0:
raise
sys.exc_clear()
self._wait(self._write_event, timeout_exc=_SSLErrorWriteTimeout)
else:
raise
def unwrap(self):
if not self._sslobj:
raise ValueError("No SSL wrapper around " + str(self))
s = self._sslobj_shutdown()
self._sslobj = None
return socket(_sock=s)
def shutdown(self, how):
self._sslobj = None
socket.shutdown(self, how)
def close(self):
if self._makefile_refs < 1:
self._sslobj = None
socket.close(self)
else:
self._makefile_refs -= 1
if PYPY:
def _reuse(self):
self._makefile_refs += 1
def _drop(self):
if self._makefile_refs < 1:
self.close()
else:
self._makefile_refs -= 1
def do_handshake(self):
"""Perform a TLS/SSL handshake."""
while True:
try:
return self._sslobj.do_handshake()
except SSLError as ex:
if ex.args[0] == SSL_ERROR_WANT_READ:
if self.timeout == 0.0:
raise
sys.exc_clear()
self._wait(self._read_event, timeout_exc=_SSLErrorHandshakeTimeout)
elif ex.args[0] == SSL_ERROR_WANT_WRITE:
if self.timeout == 0.0:
raise
sys.exc_clear()
self._wait(self._write_event, timeout_exc=_SSLErrorHandshakeTimeout)
else:
raise
def connect(self, addr):
"""Connects to remote ADDR, and then wraps the connection in
an SSL channel."""
# 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._sslobj:
raise ValueError("attempt to connect already-connected SSLSocket!")
socket.connect(self, addr)
if self.ciphers is None:
self._sslobj = _ssl.sslwrap(self._sock, False, self.keyfile, self.certfile,
self.cert_reqs, self.ssl_version,
self.ca_certs)
else:
self._sslobj = _ssl.sslwrap(self._sock, False, self.keyfile, self.certfile,
self.cert_reqs, self.ssl_version,
self.ca_certs, self.ciphers)
if self.do_handshake_on_connect:
self.do_handshake()
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."""
sock = self._sock
while True:
try:
client_socket, address = sock.accept()
break
except socket_error as ex:
if ex.args[0] != EWOULDBLOCK or self.timeout == 0.0:
raise
sys.exc_clear()
self._wait(self._read_event)
sslobj = SSLSocket(client_socket,
keyfile=self.keyfile,
certfile=self.certfile,
server_side=True,
cert_reqs=self.cert_reqs,
ssl_version=self.ssl_version,
ca_certs=self.ca_certs,
do_handshake_on_connect=self.do_handshake_on_connect,
suppress_ragged_eofs=self.suppress_ragged_eofs,
ciphers=self.ciphers)
return sslobj, address
def makefile(self, mode='r', bufsize=-1):
"""Make and return a file-like object that
works with the SSL connection. Just use the code
from the socket module."""
if not PYPY:
self._makefile_refs += 1
# close=True so as to decrement the reference count when done with
# the file-like object.
return _fileobject(self, mode, bufsize, close=True)
if PYPY or not hasattr(SSLSocket, 'timeout'):
# PyPy (and certain versions of CPython) doesn't have a direct
# 'timeout' property on raw sockets, because that's not part of
# the documented specification. We may wind up wrapping a raw
# socket (when ssl is used with PyWSGI) or a gevent socket, which
# does have a read/write timeout property as an alias for
# get/settimeout, so make sure that's always the case because
# pywsgi can depend on that.
SSLSocket.timeout = property(lambda self: self.gettimeout(),
lambda self, value: self.settimeout(value))
_SSLErrorReadTimeout = SSLError('The read operation timed out')
_SSLErrorWriteTimeout = SSLError('The write operation timed out')
_SSLErrorHandshakeTimeout = SSLError('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):
"""Create a new :class:`SSLSocket` instance."""
return SSLSocket(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)
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."""
if ca_certs is not None:
cert_reqs = CERT_REQUIRED
else:
cert_reqs = CERT_NONE
s = wrap_socket(socket(), ssl_version=ssl_version,
cert_reqs=cert_reqs, ca_certs=ca_certs)
s.connect(addr)
dercert = s.getpeercert(True)
s.close()
return DER_cert_to_PEM_cert(dercert)
def sslwrap_simple(sock, keyfile=None, certfile=None):
"""A replacement for the old socket.ssl function. Designed
for compatibility with Python 2.5 and earlier. Will disappear in
Python 3.0."""
return SSLSocket(sock, keyfile, certfile)