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#
# * Redistributions of source code must retain the above copyright
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# * Redistributions in binary form must reproduce the above
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# in the documentation and/or other materials provided with the
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"""Abstraction to simplify socket use for Python < 2.6
This will attempt to use the ssl module and the new
socket.create_connection method, but fall back to the old
methods if those are unavailable.
"""
import logging
import socket
logger = logging.getLogger(__name__)
try:
import ssl
ssl.wrap_socket # make demandimporters load the module
have_ssl = True
except ImportError:
import httplib
import urllib2
have_ssl = getattr(urllib2, 'HTTPSHandler', False)
ssl = False
try:
create_connection = socket.create_connection
except AttributeError:
def create_connection(address):
host, port = address
msg = "getaddrinfo returns an empty list"
sock = None
for res in socket.getaddrinfo(host, port, 0,
socket.SOCK_STREAM):
af, socktype, proto, _canonname, sa = res
try:
sock = socket.socket(af, socktype, proto)
logger.info("connect: (%s, %s)", host, port)
sock.connect(sa)
except socket.error, msg:
logger.info('connect fail: %s %s', host, port)
if sock:
sock.close()
sock = None
continue
break
if not sock:
raise socket.error, msg
return sock
if ssl:
wrap_socket = ssl.wrap_socket
CERT_NONE = ssl.CERT_NONE
CERT_OPTIONAL = ssl.CERT_OPTIONAL
CERT_REQUIRED = ssl.CERT_REQUIRED
else:
class FakeSocket(httplib.FakeSocket):
"""Socket wrapper that supports SSL.
"""
# backport the behavior from Python 2.6, which is to busy wait
# on the socket instead of anything nice. Sigh.
# See http://bugs.python.org/issue3890 for more info.
def recv(self, buflen=1024, flags=0):
"""ssl-aware wrapper around socket.recv
"""
if flags != 0:
raise ValueError(
"non-zero flags not allowed in calls to recv() on %s" %
self.__class__)
while True:
try:
return self._ssl.read(buflen)
except socket.sslerror, x:
if x.args[0] == socket.SSL_ERROR_WANT_READ:
continue
else:
raise x
_PROTOCOL_SSLv23 = 2
CERT_NONE = 0
CERT_OPTIONAL = 1
CERT_REQUIRED = 2
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):
if cert_reqs != CERT_NONE and ca_certs:
raise CertificateValidationUnsupported(
'SSL certificate validation requires the ssl module'
'(included in Python 2.6 and later.)')
sslob = socket.ssl(sock)
# borrow httplib's workaround for no ssl.wrap_socket
sock = FakeSocket(sock, sslob)
return sock
class CertificateValidationUnsupported(Exception):
"""Exception raised when cert validation is requested but unavailable."""
# no-check-code