path: root/Lib/test/test_ssl.py

# Test the support for SSL and sockets

import sys
import unittest
from test import support
import socket
import select
import time
import gc
import os
import errno
import pprint
import tempfile
import urllib.parse, urllib.request
import traceback
import asyncore
import weakref
import platform
import functools

from http.server import HTTPServer, SimpleHTTPRequestHandler

# Optionally test SSL support, if we have it in the tested platform
skip_expected = False
try:
    import ssl
except ImportError:
    skip_expected = True
else:
    PROTOCOLS = [
        ssl.PROTOCOL_SSLv2, ssl.PROTOCOL_SSLv3,
        ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_TLSv1
    ]

HOST = support.HOST

data_file = lambda name: os.path.join(os.path.dirname(__file__), name)

CERTFILE = data_file("keycert.pem")
BYTES_CERTFILE = os.fsencode(CERTFILE)
ONLYCERT = data_file("ssl_cert.pem")
ONLYKEY = data_file("ssl_key.pem")
BYTES_ONLYCERT = os.fsencode(ONLYCERT)
BYTES_ONLYKEY = os.fsencode(ONLYKEY)
CAPATH = data_file("capath")
BYTES_CAPATH = os.fsencode(CAPATH)

SVN_PYTHON_ORG_ROOT_CERT = data_file("https_svn_python_org_root.pem")

EMPTYCERT = data_file("nullcert.pem")
BADCERT = data_file("badcert.pem")
WRONGCERT = data_file("XXXnonexisting.pem")
BADKEY = data_file("badkey.pem")


def handle_error(prefix):
    exc_format = ' '.join(traceback.format_exception(*sys.exc_info()))
    if support.verbose:
        sys.stdout.write(prefix + exc_format)

def can_clear_options():
    # 0.9.8m or higher
    return ssl.OPENSSL_VERSION_INFO >= (0, 9, 8, 13, 15)

def no_sslv2_implies_sslv3_hello():
    # 0.9.7h or higher
    return ssl.OPENSSL_VERSION_INFO >= (0, 9, 7, 8, 15)


# Issue #9415: Ubuntu hijacks their OpenSSL and forcefully disables SSLv2
def skip_if_broken_ubuntu_ssl(func):
    @functools.wraps(func)
    def f(*args, **kwargs):
        try:
            ssl.SSLContext(ssl.PROTOCOL_SSLv2)
        except ssl.SSLError:
            if (ssl.OPENSSL_VERSION_INFO == (0, 9, 8, 15, 15) and
                platform.linux_distribution() == ('debian', 'squeeze/sid', '')):
                raise unittest.SkipTest("Patched Ubuntu OpenSSL breaks behaviour")
        return func(*args, **kwargs)
    return f


class BasicSocketTests(unittest.TestCase):

    def test_constants(self):
        ssl.PROTOCOL_SSLv2
        ssl.PROTOCOL_SSLv23
        ssl.PROTOCOL_SSLv3
        ssl.PROTOCOL_TLSv1
        ssl.CERT_NONE
        ssl.CERT_OPTIONAL
        ssl.CERT_REQUIRED

    def test_random(self):
        v = ssl.RAND_status()
        if support.verbose:
            sys.stdout.write("\n RAND_status is %d (%s)\n"
                             % (v, (v and "sufficient randomness") or
                                "insufficient randomness"))
        try:
            ssl.RAND_egd(1)
        except TypeError:
            pass
        else:
            print("didn't raise TypeError")
        ssl.RAND_add("this is a random string", 75.0)

    def test_parse_cert(self):
        # note that this uses an 'unofficial' function in _ssl.c,
        # provided solely for this test, to exercise the certificate
        # parsing code
        p = ssl._ssl._test_decode_cert(CERTFILE, False)
        if support.verbose:
            sys.stdout.write("\n" + pprint.pformat(p) + "\n")

    def test_DER_to_PEM(self):
        with open(SVN_PYTHON_ORG_ROOT_CERT, 'r') as f:
            pem = f.read()
        d1 = ssl.PEM_cert_to_DER_cert(pem)
        p2 = ssl.DER_cert_to_PEM_cert(d1)
        d2 = ssl.PEM_cert_to_DER_cert(p2)
        self.assertEqual(d1, d2)
        if not p2.startswith(ssl.PEM_HEADER + '\n'):
            self.fail("DER-to-PEM didn't include correct header:\n%r\n" % p2)
        if not p2.endswith('\n' + ssl.PEM_FOOTER + '\n'):
            self.fail("DER-to-PEM didn't include correct footer:\n%r\n" % p2)

    def test_openssl_version(self):
        n = ssl.OPENSSL_VERSION_NUMBER
        t = ssl.OPENSSL_VERSION_INFO
        s = ssl.OPENSSL_VERSION
        self.assertIsInstance(n, int)
        self.assertIsInstance(t, tuple)
        self.assertIsInstance(s, str)
        # Some sanity checks follow
        # >= 0.9
        self.assertGreaterEqual(n, 0x900000)
        # < 2.0
        self.assertLess(n, 0x20000000)
        major, minor, fix, patch, status = t
        self.assertGreaterEqual(major, 0)
        self.assertLess(major, 2)
        self.assertGreaterEqual(minor, 0)
        self.assertLess(minor, 256)
        self.assertGreaterEqual(fix, 0)
        self.assertLess(fix, 256)
        self.assertGreaterEqual(patch, 0)
        self.assertLessEqual(patch, 26)
        self.assertGreaterEqual(status, 0)
        self.assertLessEqual(status, 15)
        # Version string as returned by OpenSSL, the format might change
        self.assertTrue(s.startswith("OpenSSL {:d}.{:d}.{:d}".format(major, minor, fix)),
                        (s, t))

    def test_ciphers(self):
        if not support.is_resource_enabled('network'):
            return
        remote = ("svn.python.org", 443)
        s = ssl.wrap_socket(socket.socket(socket.AF_INET),
                            cert_reqs=ssl.CERT_NONE, ciphers="ALL")
        s.connect(remote)
        s = ssl.wrap_socket(socket.socket(socket.AF_INET),
                            cert_reqs=ssl.CERT_NONE, ciphers="DEFAULT")
        s.connect(remote)
        # Error checking can happen at instantiation or when connecting
        with self.assertRaisesRegexp(ssl.SSLError, "No cipher can be selected"):
            s = ssl.wrap_socket(socket.socket(socket.AF_INET),
                                cert_reqs=ssl.CERT_NONE, ciphers="^$:,;?*'dorothyx")
            s.connect(remote)

    @support.cpython_only
    def test_refcycle(self):
        # Issue #7943: an SSL object doesn't create reference cycles with
        # itself.
        s = socket.socket(socket.AF_INET)
        ss = ssl.wrap_socket(s)
        wr = weakref.ref(ss)
        del ss
        self.assertEqual(wr(), None)

    def test_timeout(self):
        # Issue #8524: when creating an SSL socket, the timeout of the
        # original socket should be retained.
        for timeout in (None, 0.0, 5.0):
            s = socket.socket(socket.AF_INET)
            s.settimeout(timeout)
            ss = ssl.wrap_socket(s)
            self.assertEqual(timeout, ss.gettimeout())


class ContextTests(unittest.TestCase):

    @skip_if_broken_ubuntu_ssl
    def test_constructor(self):
        ctx = ssl.SSLContext(ssl.PROTOCOL_SSLv2)
        ctx = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
        ctx = ssl.SSLContext(ssl.PROTOCOL_SSLv3)
        ctx = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
        self.assertRaises(TypeError, ssl.SSLContext)
        self.assertRaises(ValueError, ssl.SSLContext, -1)
        self.assertRaises(ValueError, ssl.SSLContext, 42)

    @skip_if_broken_ubuntu_ssl
    def test_protocol(self):
        for proto in PROTOCOLS:
            ctx = ssl.SSLContext(proto)
            self.assertEqual(ctx.protocol, proto)

    def test_ciphers(self):
        ctx = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
        ctx.set_ciphers("ALL")
        ctx.set_ciphers("DEFAULT")
        with self.assertRaisesRegexp(ssl.SSLError, "No cipher can be selected"):
            ctx.set_ciphers("^$:,;?*'dorothyx")

    @skip_if_broken_ubuntu_ssl
    def test_options(self):
        ctx = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
        # OP_ALL is the default value
        self.assertEqual(ssl.OP_ALL, ctx.options)
        ctx.options |= ssl.OP_NO_SSLv2
        self.assertEqual(ssl.OP_ALL | ssl.OP_NO_SSLv2,
                         ctx.options)
        ctx.options |= ssl.OP_NO_SSLv3
        self.assertEqual(ssl.OP_ALL | ssl.OP_NO_SSLv2 | ssl.OP_NO_SSLv3,
                         ctx.options)
        if can_clear_options():
            ctx.options = (ctx.options & ~ssl.OP_NO_SSLv2) | ssl.OP_NO_TLSv1
            self.assertEqual(ssl.OP_ALL | ssl.OP_NO_TLSv1 | ssl.OP_NO_SSLv3,
                             ctx.options)
            ctx.options = 0
            self.assertEqual(0, ctx.options)
        else:
            with self.assertRaises(ValueError):
                ctx.options = 0

    def test_verify(self):
        ctx = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
        # Default value
        self.assertEqual(ctx.verify_mode, ssl.CERT_NONE)
        ctx.verify_mode = ssl.CERT_OPTIONAL
        self.assertEqual(ctx.verify_mode, ssl.CERT_OPTIONAL)
        ctx.verify_mode = ssl.CERT_REQUIRED
        self.assertEqual(ctx.verify_mode, ssl.CERT_REQUIRED)
        ctx.verify_mode = ssl.CERT_NONE
        self.assertEqual(ctx.verify_mode, ssl.CERT_NONE)
        with self.assertRaises(TypeError):
            ctx.verify_mode = None
        with self.assertRaises(ValueError):
            ctx.verify_mode = 42

    def test_load_cert_chain(self):
        ctx = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
        # Combined key and cert in a single file
        ctx.load_cert_chain(CERTFILE)
        ctx.load_cert_chain(CERTFILE, keyfile=CERTFILE)
        self.assertRaises(TypeError, ctx.load_cert_chain, keyfile=CERTFILE)
        with self.assertRaisesRegexp(ssl.SSLError, "system lib"):
            ctx.load_cert_chain(WRONGCERT)
        with self.assertRaisesRegexp(ssl.SSLError, "PEM lib"):
            ctx.load_cert_chain(BADCERT)
        with self.assertRaisesRegexp(ssl.SSLError, "PEM lib"):
            ctx.load_cert_chain(EMPTYCERT)
        # Separate key and cert
        ctx = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
        ctx.load_cert_chain(ONLYCERT, ONLYKEY)
        ctx.load_cert_chain(certfile=ONLYCERT, keyfile=ONLYKEY)
        ctx.load_cert_chain(certfile=BYTES_ONLYCERT, keyfile=BYTES_ONLYKEY)
        with self.assertRaisesRegexp(ssl.SSLError, "PEM lib"):
            ctx.load_cert_chain(ONLYCERT)
        with self.assertRaisesRegexp(ssl.SSLError, "PEM lib"):
            ctx.load_cert_chain(ONLYKEY)
        with self.assertRaisesRegexp(ssl.SSLError, "PEM lib"):
            ctx.load_cert_chain(certfile=ONLYKEY, keyfile=ONLYCERT)
        # Mismatching key and cert
        ctx = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
        with self.assertRaisesRegexp(ssl.SSLError, "key values mismatch"):
            ctx.load_cert_chain(CERTFILE, ONLYKEY)

    def test_load_verify_locations(self):
        ctx = ssl.SSLContext(ssl.PROTOCOL_TLSv1)
        ctx.load_verify_locations(CERTFILE)
        ctx.load_verify_locations(cafile=CERTFILE, capath=None)
        ctx.load_verify_locations(BYTES_CERTFILE)
        ctx.load_verify_locations(cafile=BYTES_CERTFILE, capath=None)
        self.assertRaises(TypeError, ctx.load_verify_locations)
        self.assertRaises(TypeError, ctx.load_verify_locations, None, None)
        with self.assertRaisesRegexp(ssl.SSLError, "system lib"):
            ctx.load_verify_locations(WRONGCERT)
        with self.assertRaisesRegexp(ssl.SSLError, "PEM lib"):
            ctx.load_verify_locations(BADCERT)
        ctx.load_verify_locations(CERTFILE, CAPATH)
        ctx.load_verify_locations(CERTFILE, capath=BYTES_CAPATH)


class NetworkedTests(unittest.TestCase):

    def test_connect(self):
        s = ssl.wrap_socket(socket.socket(socket.AF_INET),
                            cert_reqs=ssl.CERT_NONE)
        try:
            s.connect(("svn.python.org", 443))
            self.assertEqual({}, s.getpeercert())
        finally:
            s.close()

        # this should fail because we have no verification certs
        s = ssl.wrap_socket(socket.socket(socket.AF_INET),
                            cert_reqs=ssl.CERT_REQUIRED)
        self.assertRaisesRegexp(ssl.SSLError, "certificate verify failed",
                                s.connect, ("svn.python.org", 443))
        s.close()

        # this should succeed because we specify the root cert
        s = ssl.wrap_socket(socket.socket(socket.AF_INET),
                            cert_reqs=ssl.CERT_REQUIRED,
                            ca_certs=SVN_PYTHON_ORG_ROOT_CERT)
        try:
            s.connect(("svn.python.org", 443))
            self.assertTrue(s.getpeercert())
        finally:
            s.close()

    def test_connect_with_context(self):
        # Same as test_connect, but with a separately created context
        ctx = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
        s = ctx.wrap_socket(socket.socket(socket.AF_INET))
        s.connect(("svn.python.org", 443))
        try:
            self.assertEqual({}, s.getpeercert())
        finally:
            s.close()
        # This should fail because we have no verification certs
        ctx.verify_mode = ssl.CERT_REQUIRED
        s = ctx.wrap_socket(socket.socket(socket.AF_INET))
        self.assertRaisesRegexp(ssl.SSLError, "certificate verify failed",
                                s.connect, ("svn.python.org", 443))
        s.close()
        # This should succeed because we specify the root cert
        ctx.load_verify_locations(SVN_PYTHON_ORG_ROOT_CERT)
        s = ctx.wrap_socket(socket.socket(socket.AF_INET))
        s.connect(("svn.python.org", 443))
        try:
            cert = s.getpeercert()
            self.assertTrue(cert)
        finally:
            s.close()

    def test_connect_capath(self):
        # Verify server certificates using the `capath` argument
        # NOTE: the subject hashing algorithm has been changed between
        # OpenSSL 0.9.8n and 1.0.0, as a result the capath directory must
        # contain both versions of each certificate (same content, different
        # filename) for this test to be portable across OpenSSL releases.
        ctx = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
        ctx.verify_mode = ssl.CERT_REQUIRED
        ctx.load_verify_locations(capath=CAPATH)
        s = ctx.wrap_socket(socket.socket(socket.AF_INET))
        s.connect(("svn.python.org", 443))
        try:
            cert = s.getpeercert()
            self.assertTrue(cert)
        finally:
            s.close()
        # Same with a bytes `capath` argument
        ctx = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
        ctx.verify_mode = ssl.CERT_REQUIRED
        ctx.load_verify_locations(capath=BYTES_CAPATH)
        s = ctx.wrap_socket(socket.socket(socket.AF_INET))
        s.connect(("svn.python.org", 443))
        try:
            cert = s.getpeercert()
            self.assertTrue(cert)
        finally:
            s.close()

    @unittest.skipIf(os.name == "nt", "Can't use a socket as a file under Windows")
    def test_makefile_close(self):
        # Issue #5238: creating a file-like object with makefile() shouldn't
        # delay closing the underlying "real socket" (here tested with its
        # file descriptor, hence skipping the test under Windows).
        ss = ssl.wrap_socket(socket.socket(socket.AF_INET))
        ss.connect(("svn.python.org", 443))
        fd = ss.fileno()
        f = ss.makefile()
        f.close()
        # The fd is still open
        os.read(fd, 0)
        # Closing the SSL socket should close the fd too
        ss.close()
        gc.collect()
        with self.assertRaises(OSError) as e:
            os.read(fd, 0)
        self.assertEqual(e.exception.errno, errno.EBADF)

    def test_non_blocking_handshake(self):
        s = socket.socket(socket.AF_INET)
        s.connect(("svn.python.org", 443))
        s.setblocking(False)
        s = ssl.wrap_socket(s,
                            cert_reqs=ssl.CERT_NONE,
                            do_handshake_on_connect=False)
        count = 0
        while True:
            try:
                count += 1
                s.do_handshake()
                break
            except ssl.SSLError as err:
                if err.args[0] == ssl.SSL_ERROR_WANT_READ:
                    select.select([s], [], [])
                elif err.args[0] == ssl.SSL_ERROR_WANT_WRITE:
                    select.select([], [s], [])
                else:
                    raise
        s.close()
        if support.verbose:
            sys.stdout.write("\nNeeded %d calls to do_handshake() to establish session.\n" % count)

    def test_get_server_certificate(self):
        pem = ssl.get_server_certificate(("svn.python.org", 443))
        if not pem:
            self.fail("No server certificate on svn.python.org:443!")

        return

        try:
            pem = ssl.get_server_certificate(("svn.python.org", 443), ca_certs=CERTFILE)
        except ssl.SSLError as x:
            #should fail
            if support.verbose:
                sys.stdout.write("%s\n" % x)
        else:
            self.fail("Got server certificate %s for svn.python.org!" % pem)

        pem = ssl.get_server_certificate(("svn.python.org", 443), ca_certs=SVN_PYTHON_ORG_ROOT_CERT)
        if not pem:
            self.fail("No server certificate on svn.python.org:443!")
        if support.verbose:
            sys.stdout.write("\nVerified certificate for svn.python.org:443 is\n%s\n" % pem)

    def test_algorithms(self):
        # Issue #8484: all algorithms should be available when verifying a
        # certificate.
        # SHA256 was added in OpenSSL 0.9.8
        if ssl.OPENSSL_VERSION_INFO < (0, 9, 8, 0, 15):
            self.skipTest("SHA256 not available on %r" % ssl.OPENSSL_VERSION)
        # NOTE: https://sha256.tbs-internet.com is another possible test host
        remote = ("sha2.hboeck.de", 443)
        sha256_cert = os.path.join(os.path.dirname(__file__), "sha256.pem")
        s = ssl.wrap_socket(socket.socket(socket.AF_INET),
                            cert_reqs=ssl.CERT_REQUIRED,
                            ca_certs=sha256_cert,)
        with support.transient_internet():
            try:
                s.connect(remote)
                if support.verbose:
                    sys.stdout.write("\nCipher with %r is %r\n" %
                                     (remote, s.cipher()))
                    sys.stdout.write("Certificate is:\n%s\n" %
                                     pprint.pformat(s.getpeercert()))
            finally:
                s.close()


try:
    import threading
except ImportError:
    _have_threads = False
else:
    _have_threads = True

    class ThreadedEchoServer(threading.Thread):

        class ConnectionHandler(threading.Thread):

            """A mildly complicated class, because we want it to work both
            with and without the SSL wrapper around the socket connection, so
            that we can test the STARTTLS functionality."""

            def __init__(self, server, connsock, addr):
                self.server = server
                self.running = False
                self.sock = connsock
                self.addr = addr
                self.sock.setblocking(1)
                self.sslconn = None
                threading.Thread.__init__(self)
                self.daemon = True

            def wrap_conn(self):
                try:
                    self.sslconn = self.server.context.wrap_socket(
                        self.sock, server_side=True)
                except ssl.SSLError:
                    # XXX Various errors can have happened here, for example
                    # a mismatching protocol version, an invalid certificate,
                    # or a low-level bug. This should be made more discriminating.
                    if self.server.chatty:
                        handle_error("\n server:  bad connection attempt from " + repr(self.addr) + ":\n")
                    self.running = False
                    self.server.stop()
                    self.close()
                    return False
                else:
                    if self.server.context.verify_mode == ssl.CERT_REQUIRED:
                        cert = self.sslconn.getpeercert()
                        if support.verbose and self.server.chatty:
                            sys.stdout.write(" client cert is " + pprint.pformat(cert) + "\n")
                        cert_binary = self.sslconn.getpeercert(True)
                        if support.verbose and self.server.chatty:
                            sys.stdout.write(" cert binary is " + str(len(cert_binary)) + " bytes\n")
                    cipher = self.sslconn.cipher()
                    if support.verbose and self.server.chatty:
                        sys.stdout.write(" server: connection cipher is now " + str(cipher) + "\n")
                    return True

            def read(self):
                if self.sslconn:
                    return self.sslconn.read()
                else:
                    return self.sock.recv(1024)

            def write(self, bytes):
                if self.sslconn:
                    return self.sslconn.write(bytes)
                else:
                    return self.sock.send(bytes)

            def close(self):
                if self.sslconn:
                    self.sslconn.close()
                else:
                    self.sock.close()

            def run(self):
                self.running = True
                if not self.server.starttls_server:
                    if not self.wrap_conn():
                        return
                while self.running:
                    try:
                        msg = self.read()
                        stripped = msg.strip()
                        if not stripped:
                            # eof, so quit this handler
                            self.running = False
                            self.close()
                        elif stripped == b'over':
                            if support.verbose and self.server.connectionchatty:
                                sys.stdout.write(" server: client closed connection\n")
                            self.close()
                            return
                        elif (self.server.starttls_server and
                              stripped == b'STARTTLS'):
                            if support.verbose and self.server.connectionchatty:
                                sys.stdout.write(" server: read STARTTLS from client, sending OK...\n")
                            self.write(b"OK\n")
                            if not self.wrap_conn():
                                return
                        elif (self.server.starttls_server and self.sslconn
                              and stripped == b'ENDTLS'):
                            if support.verbose and self.server.connectionchatty:
                                sys.stdout.write(" server: read ENDTLS from client, sending OK...\n")
                            self.write(b"OK\n")
                            self.sock = self.sslconn.unwrap()
                            self.sslconn = None
                            if support.verbose and self.server.connectionchatty:
                                sys.stdout.write(" server: connection is now unencrypted...\n")
                        else:
                            if (support.verbose and
                                self.server.connectionchatty):
                                ctype = (self.sslconn and "encrypted") or "unencrypted"
                                sys.stdout.write(" server: read %r (%s), sending back %r (%s)...\n"
                                                 % (msg, ctype, msg.lower(), ctype))
                            self.write(msg.lower())
                    except socket.error:
                        if self.server.chatty:
                            handle_error("Test server failure:\n")
                        self.close()
                        self.running = False
                        # normally, we'd just stop here, but for the test
                        # harness, we want to stop the server
                        self.server.stop()

        def __init__(self, certificate=None, ssl_version=None,
                     certreqs=None, cacerts=None,
                     chatty=True, connectionchatty=False, starttls_server=False,
                     ciphers=None, context=None):
            if context:
                self.context = context
            else:
                self.context = ssl.SSLContext(ssl_version
                                              if ssl_version is not None
                                              else ssl.PROTOCOL_TLSv1)
                self.context.verify_mode = (certreqs if certreqs is not None
                                            else ssl.CERT_NONE)
                if cacerts:
                    self.context.load_verify_locations(cacerts)
                if certificate:
                    self.context.load_cert_chain(certificate)
                if ciphers:
                    self.context.set_ciphers(ciphers)
            self.chatty = chatty
            self.connectionchatty = connectionchatty
            self.starttls_server = starttls_server
            self.sock = socket.socket()
            self.port = support.bind_port(self.sock)
            self.flag = None
            self.active = False
            threading.Thread.__init__(self)
            self.daemon = True

        def start(self, flag=None):
            self.flag = flag
            threading.Thread.start(self)

        def run(self):
            self.sock.settimeout(0.05)
            self.sock.listen(5)
            self.active = True
            if self.flag:
                # signal an event
                self.flag.set()
            while self.active:
                try:
                    newconn, connaddr = self.sock.accept()
                    if support.verbose and self.chatty:
                        sys.stdout.write(' server:  new connection from '
                                         + repr(connaddr) + '\n')
                    handler = self.ConnectionHandler(self, newconn, connaddr)
                    handler.start()
                except socket.timeout:
                    pass
                except KeyboardInterrupt:
                    self.stop()
            self.sock.close()

        def stop(self):
            self.active = False

    class OurHTTPSServer(threading.Thread):

        # This one's based on HTTPServer, which is based on SocketServer

        class HTTPSServer(HTTPServer):

            def __init__(self, server_address, RequestHandlerClass, certfile):
                HTTPServer.__init__(self, server_address, RequestHandlerClass)
                # we assume the certfile contains both private key and certificate
                self.certfile = certfile
                self.allow_reuse_address = True

            def __str__(self):
                return ('<%s %s:%s>' %
                        (self.__class__.__name__,
                         self.server_name,
                         self.server_port))

            def get_request(self):
                # override this to wrap socket with SSL
                sock, addr = self.socket.accept()
                sslconn = ssl.wrap_socket(sock, server_side=True,
                                          certfile=self.certfile)
                return sslconn, addr

        class RootedHTTPRequestHandler(SimpleHTTPRequestHandler):
            # need to override translate_path to get a known root,
            # instead of using os.curdir, since the test could be
            # run from anywhere

            server_version = "TestHTTPS/1.0"

            root = None

            def translate_path(self, path):
                """Translate a /-separated PATH to the local filename syntax.

                Components that mean special things to the local file system
                (e.g. drive or directory names) are ignored.  (XXX They should
                probably be diagnosed.)

                """
                # abandon query parameters
                path = urllib.parse.urlparse(path)[2]
                path = os.path.normpath(urllib.parse.unquote(path))
                words = path.split('/')
                words = filter(None, words)
                path = self.root
                for word in words:
                    drive, word = os.path.splitdrive(word)
                    head, word = os.path.split(word)
                    if word in self.root: continue
                    path = os.path.join(path, word)
                return path

            def log_message(self, format, *args):
                # we override this to suppress logging unless "verbose"

                if support.verbose:
                    sys.stdout.write(" server (%s:%d %s):\n   [%s] %s\n" %
                                     (self.server.server_address,
                                      self.server.server_port,
                                      self.request.cipher(),
                                      self.log_date_time_string(),
                                      format%args))


        def __init__(self, certfile):
            self.flag = None
            self.RootedHTTPRequestHandler.root = os.path.split(CERTFILE)[0]
            self.server = self.HTTPSServer(
                (HOST, 0), self.RootedHTTPRequestHandler, certfile)
            self.port = self.server.server_port
            threading.Thread.__init__(self)
            self.daemon = True

        def __str__(self):
            return "<%s %s>" % (self.__class__.__name__, self.server)

        def start(self, flag=None):
            self.flag = flag
            threading.Thread.start(self)

        def run(self):
            if self.flag:
                self.flag.set()
            self.server.serve_forever(0.05)

        def stop(self):
            self.server.shutdown()


    class AsyncoreEchoServer(threading.Thread):

        # this one's based on asyncore.dispatcher

        class EchoServer (asyncore.dispatcher):

            class ConnectionHandler (asyncore.dispatcher_with_send):

                def __init__(self, conn, certfile):
                    self.socket = ssl.wrap_socket(conn, server_side=True,
                                                  certfile=certfile,
                                                  do_handshake_on_connect=False)
                    asyncore.dispatcher_with_send.__init__(self, self.socket)
                    self._ssl_accepting = True
                    self._do_ssl_handshake()

                def readable(self):
                    if isinstance(self.socket, ssl.SSLSocket):
                        while self.socket.pending() > 0:
                            self.handle_read_event()
                    return True

                def _do_ssl_handshake(self):
                    try:
                        self.socket.do_handshake()
                    except ssl.SSLError as err:
                        if err.args[0] in (ssl.SSL_ERROR_WANT_READ,
                                           ssl.SSL_ERROR_WANT_WRITE):
                            return
                        elif err.args[0] == ssl.SSL_ERROR_EOF:
                            return self.handle_close()
                        raise
                    except socket.error as err:
                        if err.args[0] == errno.ECONNABORTED:
                            return self.handle_close()
                    else:
                        self._ssl_accepting = False

                def handle_read(self):
                    if self._ssl_accepting:
                        self._do_ssl_handshake()
                    else:
                        data = self.recv(1024)
                        if support.verbose:
                            sys.stdout.write(" server:  read %s from client\n" % repr(data))
                        if not data:
                            self.close()
                        else:
                            self.send(data.lower())

                def handle_close(self):
                    self.close()
                    if support.verbose:
                        sys.stdout.write(" server:  closed connection %s\n" % self.socket)

                def handle_error(self):
                    raise

            def __init__(self, certfile):
                self.certfile = certfile
                sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
                self.port = support.bind_port(sock, '')
                asyncore.dispatcher.__init__(self, sock)
                self.listen(5)

            def handle_accept(self):
                sock_obj, addr = self.accept()
                if support.verbose:
                    sys.stdout.write(" server:  new connection from %s:%s\n" %addr)
                self.ConnectionHandler(sock_obj, self.certfile)

            def handle_error(self):
                raise

        def __init__(self, certfile):
            self.flag = None
            self.active = False
            self.server = self.EchoServer(certfile)
            self.port = self.server.port
            threading.Thread.__init__(self)
            self.daemon = True

        def __str__(self):
            return "<%s %s>" % (self.__class__.__name__, self.server)

        def start (self, flag=None):
            self.flag = flag
            threading.Thread.start(self)

        def run(self):
            self.active = True
            if self.flag:
                self.flag.set()
            while self.active:
                try:
                    asyncore.loop(1)
                except:
                    pass

        def stop(self):
            self.active = False
            self.server.close()

    def bad_cert_test(certfile):
        """
        Launch a server with CERT_REQUIRED, and check that trying to
        connect to it with the given client certificate fails.
        """
        server = ThreadedEchoServer(CERTFILE,
                                    certreqs=ssl.CERT_REQUIRED,
                                    cacerts=CERTFILE, chatty=False,
                                    connectionchatty=False)
        flag = threading.Event()
        server.start(flag)
        # wait for it to start
        flag.wait()
        # try to connect
        try:
            try:
                s = ssl.wrap_socket(socket.socket(),
                                    certfile=certfile,
                                    ssl_version=ssl.PROTOCOL_TLSv1)
                s.connect((HOST, server.port))
            except ssl.SSLError as x:
                if support.verbose:
                    sys.stdout.write("\nSSLError is %s\n" % x.args[1])
            except socket.error as x:
                if support.verbose:
                    sys.stdout.write("\nsocket.error is %s\n" % x[1])
            else:
                raise AssertionError("Use of invalid cert should have failed!")
        finally:
            server.stop()
            server.join()

    def server_params_test(client_context, server_context, indata=b"FOO\n",
                           chatty=True, connectionchatty=False):
        """
        Launch a server, connect a client to it and try various reads
        and writes.
        """
        server = ThreadedEchoServer(context=server_context,
                                    chatty=chatty,
                                    connectionchatty=False)
        flag = threading.Event()
        server.start(flag)
        # wait for it to start
        flag.wait()
        # try to connect
        try:
            s = client_context.wrap_socket(socket.socket())
            s.connect((HOST, server.port))
            for arg in [indata, bytearray(indata), memoryview(indata)]:
                if connectionchatty:
                    if support.verbose:
                        sys.stdout.write(
                            " client:  sending %r...\n" % indata)
                s.write(arg)
                outdata = s.read()
                if connectionchatty:
                    if support.verbose:
                        sys.stdout.write(" client:  read %r\n" % outdata)
                if outdata != indata.lower():
                    raise AssertionError(
                        "bad data <<%r>> (%d) received; expected <<%r>> (%d)\n"
                        % (outdata[:20], len(outdata),
                           indata[:20].lower(), len(indata)))
            s.write(b"over\n")
            if connectionchatty:
                if support.verbose:
                    sys.stdout.write(" client:  closing connection.\n")
            s.close()
        finally:
            server.stop()
            server.join()

    def try_protocol_combo(server_protocol, client_protocol, expect_success,
                           certsreqs=None, server_options=0, client_options=0):
        if certsreqs is None:
            certsreqs = ssl.CERT_NONE
        certtype = {
            ssl.CERT_NONE: "CERT_NONE",
            ssl.CERT_OPTIONAL: "CERT_OPTIONAL",
            ssl.CERT_REQUIRED: "CERT_REQUIRED",
        }[certsreqs]
        if support.verbose:
            formatstr = (expect_success and " %s->%s %s\n") or " {%s->%s} %s\n"
            sys.stdout.write(formatstr %
                             (ssl.get_protocol_name(client_protocol),
                              ssl.get_protocol_name(server_protocol),
                              certtype))
        client_context = ssl.SSLContext(client_protocol)
        client_context.options = ssl.OP_ALL | client_options
        server_context = ssl.SSLContext(server_protocol)
        server_context.options = ssl.OP_ALL | server_options
        for ctx in (client_context, server_context):
            ctx.verify_mode = certsreqs
            # NOTE: we must enable "ALL" ciphers, otherwise an SSLv23 client
            # will send an SSLv3 hello (rather than SSLv2) starting from
            # OpenSSL 1.0.0 (see issue #8322).
            ctx.set_ciphers("ALL")
            ctx.load_cert_chain(CERTFILE)
            ctx.load_verify_locations(CERTFILE)
        try:
            server_params_test(client_context, server_context,
                               chatty=False, connectionchatty=False)
        # Protocol mismatch can result in either an SSLError, or a
        # "Connection reset by peer" error.
        except ssl.SSLError:
            if expect_success:
                raise
        except socket.error as e:
            if expect_success or e.errno != errno.ECONNRESET:
                raise
        else:
            if not expect_success:
                raise AssertionError(
                    "Client protocol %s succeeded with server protocol %s!"
                    % (ssl.get_protocol_name(client_protocol),
                       ssl.get_protocol_name(server_protocol)))


    class ThreadedTests(unittest.TestCase):

        @skip_if_broken_ubuntu_ssl
        def test_echo(self):
            """Basic test of an SSL client connecting to a server"""
            if support.verbose:
                sys.stdout.write("\n")
            for protocol in PROTOCOLS:
                context = ssl.SSLContext(protocol)
                context.load_cert_chain(CERTFILE)
                server_params_test(context, context,
                                   chatty=True, connectionchatty=True)

        def test_getpeercert(self):
            if support.verbose:
                sys.stdout.write("\n")
            context = ssl.SSLContext(ssl.PROTOCOL_SSLv23)
            context.verify_mode = ssl.CERT_REQUIRED
            context.load_verify_locations(CERTFILE)
            context.load_cert_chain(CERTFILE)
            server = ThreadedEchoServer(context=context, chatty=False)
            flag = threading.Event()
            server.start(flag)
            # wait for it to start
            flag.wait()
            # try to connect
            try:
                s = context.wrap_socket(socket.socket())
                s.connect((HOST, server.port))
                cert = s.getpeercert()
                self.assertTrue(cert, "Can't get peer certificate.")
                cipher = s.cipher()
                if support.verbose:
                    sys.stdout.write(pprint.pformat(cert) + '\n')
                    sys.stdout.write("Connection cipher is " + str(cipher) + '.\n')
                if 'subject' not in cert:
                    self.fail("No subject field in certificate: %s." %
                              pprint.pformat(cert))
                if ((('organizationName', 'Python Software Foundation'),)
                    not in cert['subject']):
                    self.fail(
                        "Missing or invalid 'organizationName' field in certificate subject; "
                        "should be 'Python Software Foundation'.")
                s.close()
            finally:
                server.stop()
                server.join()

        def test_empty_cert(self):
            """Connecting with an empty cert file"""
            bad_cert_test(os.path.join(os.path.dirname(__file__) or os.curdir,
                                      "nullcert.pem"))
        def test_malformed_cert(self):
            """Connecting with a badly formatted certificate (syntax error)"""
            bad_cert_test(os.path.join(os.path.dirname(__file__) or os.curdir,
                                       "badcert.pem"))
        def test_nonexisting_cert(self):
            """Connecting with a non-existing cert file"""
            bad_cert_test(os.path.join(os.path.dirname(__file__) or os.curdir,
                                       "wrongcert.pem"))
        def test_malformed_key(self):
            """Connecting with a badly formatted key (syntax error)"""
            bad_cert_test(os.path.join(os.path.dirname(__file__) or os.curdir,
                                       "badkey.pem"))

        def test_rude_shutdown(self):
            """A brutal shutdown of an SSL server should raise an IOError
            in the client when attempting handshake.
            """
            listener_ready = threading.Event()
            listener_gone = threading.Event()

            s = socket.socket()
            port = support.bind_port(s, HOST)

            # `listener` runs in a thread.  It sits in an accept() until
            # the main thread connects.  Then it rudely closes the socket,
            # and sets Event `listener_gone` to let the main thread know
            # the socket is gone.
            def listener():
                s.listen(5)
                listener_ready.set()
                s.accept()
                s.close()
                listener_gone.set()

            def connector():
                listener_ready.wait()
                c = socket.socket()
                c.connect((HOST, port))
                listener_gone.wait()
                try:
                    ssl_sock = ssl.wrap_socket(c)
                except IOError:
                    pass
                else:
                    self.fail('connecting to closed SSL socket should have failed')

            t = threading.Thread(target=listener)
            t.start()
            try:
                connector()
            finally:
                t.join()

        @skip_if_broken_ubuntu_ssl
        def test_protocol_sslv2(self):
            """Connecting to an SSLv2 server with various client options"""
            if support.verbose:
                sys.stdout.write("\n")
            try_protocol_combo(ssl.PROTOCOL_SSLv2, ssl.PROTOCOL_SSLv2, True)
            try_protocol_combo(ssl.PROTOCOL_SSLv2, ssl.PROTOCOL_SSLv2, True, ssl.CERT_OPTIONAL)
            try_protocol_combo(ssl.PROTOCOL_SSLv2, ssl.PROTOCOL_SSLv2, True, ssl.CERT_REQUIRED)
            try_protocol_combo(ssl.PROTOCOL_SSLv2, ssl.PROTOCOL_SSLv23, True)
            try_protocol_combo(ssl.PROTOCOL_SSLv2, ssl.PROTOCOL_SSLv3, False)
            try_protocol_combo(ssl.PROTOCOL_SSLv2, ssl.PROTOCOL_TLSv1, False)
            # SSLv23 client with specific SSL options
            if no_sslv2_implies_sslv3_hello():
                # No SSLv2 => client will use an SSLv3 hello on recent OpenSSLs
                try_protocol_combo(ssl.PROTOCOL_SSLv2, ssl.PROTOCOL_SSLv23, False,
                                   client_options=ssl.OP_NO_SSLv2)
            try_protocol_combo(ssl.PROTOCOL_SSLv2, ssl.PROTOCOL_SSLv23, True,
                               client_options=ssl.OP_NO_SSLv3)
            try_protocol_combo(ssl.PROTOCOL_SSLv2, ssl.PROTOCOL_SSLv23, True,
                               client_options=ssl.OP_NO_TLSv1)

        @skip_if_broken_ubuntu_ssl
        def test_protocol_sslv23(self):
            """Connecting to an SSLv23 server with various client options"""
            if support.verbose:
                sys.stdout.write("\n")
            try:
                try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_SSLv2, True)
            except (ssl.SSLError, socket.error) as x:
                # this fails on some older versions of OpenSSL (0.9.7l, for instance)
                if support.verbose:
                    sys.stdout.write(
                        " SSL2 client to SSL23 server test unexpectedly failed:\n %s\n"
                        % str(x))
            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_SSLv3, True)
            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_SSLv23, True)
            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_TLSv1, True)

            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_SSLv3, True, ssl.CERT_OPTIONAL)
            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_SSLv23, True, ssl.CERT_OPTIONAL)
            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_TLSv1, True, ssl.CERT_OPTIONAL)

            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_SSLv3, True, ssl.CERT_REQUIRED)
            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_SSLv23, True, ssl.CERT_REQUIRED)
            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_TLSv1, True, ssl.CERT_REQUIRED)

            # Server with specific SSL options
            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_SSLv3, False,
                               server_options=ssl.OP_NO_SSLv3)
            # Will choose TLSv1
            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_SSLv23, True,
                               server_options=ssl.OP_NO_SSLv2 | ssl.OP_NO_SSLv3)
            try_protocol_combo(ssl.PROTOCOL_SSLv23, ssl.PROTOCOL_TLSv1, False,
                               server_options=ssl.OP_NO_TLSv1)


        @skip_if_broken_ubuntu_ssl
        def test_protocol_sslv3(self):
            """Connecting to an SSLv3 server with various client options"""
            if support.verbose:
                sys.stdout.write("\n")
            try_protocol_combo(ssl.PROTOCOL_SSLv3, ssl.PROTOCOL_SSLv3, True)
            try_protocol_combo(ssl.PROTOCOL_SSLv3, ssl.PROTOCOL_SSLv3, True, ssl.CERT_OPTIONAL)
            try_protocol_combo(ssl.PROTOCOL_SSLv3, ssl.PROTOCOL_SSLv3, True, ssl.CERT_REQUIRED)
            try_protocol_combo(ssl.PROTOCOL_SSLv3, ssl.PROTOCOL_SSLv2, False)
            try_protocol_combo(ssl.PROTOCOL_SSLv3, ssl.PROTOCOL_SSLv23, False)
            try_protocol_combo(ssl.PROTOCOL_SSLv3, ssl.PROTOCOL_TLSv1, False)
            if no_sslv2_implies_sslv3_hello():
                # No SSLv2 => client will use an SSLv3 hello on recent OpenSSLs
                try_protocol_combo(ssl.PROTOCOL_SSLv3, ssl.PROTOCOL_SSLv23, True,
                                   client_options=ssl.OP_NO_SSLv2)

        @skip_if_broken_ubuntu_ssl
        def test_protocol_tlsv1(self):
            """Connecting to a TLSv1 server with various client options"""
            if support.verbose:
                sys.stdout.write("\n")
            try_protocol_combo(ssl.PROTOCOL_TLSv1, ssl.PROTOCOL_TLSv1, True)
            try_protocol_combo(ssl.PROTOCOL_TLSv1, ssl.PROTOCOL_TLSv1, True, ssl.CERT_OPTIONAL)
            try_protocol_combo(ssl.PROTOCOL_TLSv1, ssl.PROTOCOL_TLSv1, True, ssl.CERT_REQUIRED)
            try_protocol_combo(ssl.PROTOCOL_TLSv1, ssl.PROTOCOL_SSLv2, False)
            try_protocol_combo(ssl.PROTOCOL_TLSv1, ssl.PROTOCOL_SSLv3, False)
            try_protocol_combo(ssl.PROTOCOL_TLSv1, ssl.PROTOCOL_SSLv23, False)

        def test_starttls(self):
            """Switching from clear text to encrypted and back again."""
            msgs = (b"msg 1", b"MSG 2", b"STARTTLS", b"MSG 3", b"msg 4", b"ENDTLS", b"msg 5", b"msg 6")

            server = ThreadedEchoServer(CERTFILE,
                                        ssl_version=ssl.PROTOCOL_TLSv1,
                                        starttls_server=True,
                                        chatty=True,
                                        connectionchatty=True)
            flag = threading.Event()
            server.start(flag)
            # wait for it to start
            flag.wait()
            # try to connect
            wrapped = False
            try:
                s = socket.socket()
                s.setblocking(1)
                s.connect((HOST, server.port))
                if support.verbose:
                    sys.stdout.write("\n")
                for indata in msgs:
                    if support.verbose:
                        sys.stdout.write(
                            " client:  sending %r...\n" % indata)
                    if wrapped:
                        conn.write(indata)
                        outdata = conn.read()
                    else:
                        s.send(indata)
                        outdata = s.recv(1024)
                    msg = outdata.strip().lower()
                    if indata == b"STARTTLS" and msg.startswith(b"ok"):
                        # STARTTLS ok, switch to secure mode
                        if support.verbose:
                            sys.stdout.write(
                                " client:  read %r from server, starting TLS...\n"
                                % msg)
                        conn = ssl.wrap_socket(s, ssl_version=ssl.PROTOCOL_TLSv1)
                        wrapped = True
                    elif indata == b"ENDTLS" and msg.startswith(b"ok"):
                        # ENDTLS ok, switch back to clear text
                        if support.verbose:
                            sys.stdout.write(
                                " client:  read %r from server, ending TLS...\n"
                                % msg)
                        s = conn.unwrap()
                        wrapped = False
                    else:
                        if support.verbose:
                            sys.stdout.write(
                                " client:  read %r from server\n" % msg)
                if support.verbose:
                    sys.stdout.write(" client:  closing connection.\n")
                if wrapped:
                    conn.write(b"over\n")
                else:
                    s.send(b"over\n")
                if wrapped:
                    conn.close()
                else:
                    s.close()
            finally:
                server.stop()
                server.join()

        def test_socketserver(self):
            """Using a SocketServer to create and manage SSL connections."""
            server = OurHTTPSServer(CERTFILE)
            flag = threading.Event()
            server.start(flag)
            # wait for it to start
            flag.wait()
            # try to connect
            try:
                if support.verbose:
                    sys.stdout.write('\n')
                with open(CERTFILE, 'rb') as f:
                    d1 = f.read()
                d2 = ''
                # now fetch the same data from the HTTPS server
                url = 'https://%s:%d/%s' % (
                    HOST, server.port, os.path.split(CERTFILE)[1])
                f = urllib.request.urlopen(url)
                dlen = f.info().get("content-length")
                if dlen and (int(dlen) > 0):
                    d2 = f.read(int(dlen))
                    if support.verbose:
                        sys.stdout.write(
                            " client: read %d bytes from remote server '%s'\n"
                            % (len(d2), server))
                f.close()
                self.assertEqual(d1, d2)
            finally:
                if support.verbose:
                    sys.stdout.write('stopping server\n')
                server.stop()
                if support.verbose:
                    sys.stdout.write('joining thread\n')
                server.join()

        def test_asyncore_server(self):
            """Check the example asyncore integration."""
            indata = "TEST MESSAGE of mixed case\n"

            if support.verbose:
                sys.stdout.write("\n")

            indata = b"FOO\n"
            server = AsyncoreEchoServer(CERTFILE)
            flag = threading.Event()
            server.start(flag)
            # wait for it to start
            flag.wait()
            # try to connect
            try:
                s = ssl.wrap_socket(socket.socket())
                s.connect(('127.0.0.1', server.port))
                if support.verbose:
                    sys.stdout.write(
                        " client:  sending %r...\n" % indata)
                s.write(indata)
                outdata = s.read()
                if support.verbose:
                    sys.stdout.write(" client:  read %r\n" % outdata)
                if outdata != indata.lower():
                    self.fail(
                        "bad data <<%r>> (%d) received; expected <<%r>> (%d)\n"
                        % (outdata[:20], len(outdata),
                           indata[:20].lower(), len(indata)))
                s.write(b"over\n")
                if support.verbose:
                    sys.stdout.write(" client:  closing connection.\n")
                s.close()
            finally:
                server.stop()
                server.join()

        def test_recv_send(self):
            """Test recv(), send() and friends."""
            if support.verbose:
                sys.stdout.write("\n")

            server = ThreadedEchoServer(CERTFILE,
                                        certreqs=ssl.CERT_NONE,
                                        ssl_version=ssl.PROTOCOL_TLSv1,
                                        cacerts=CERTFILE,
                                        chatty=True,
                                        connectionchatty=False)
            flag = threading.Event()
            server.start(flag)
            # wait for it to start
            flag.wait()
            # try to connect
            s = ssl.wrap_socket(socket.socket(),
                                server_side=False,
                                certfile=CERTFILE,
                                ca_certs=CERTFILE,
                                cert_reqs=ssl.CERT_NONE,
                                ssl_version=ssl.PROTOCOL_TLSv1)
            s.connect((HOST, server.port))
            try:
                # helper methods for standardising recv* method signatures
                def _recv_into():
                    b = bytearray(b"\0"*100)
                    count = s.recv_into(b)
                    return b[:count]

                def _recvfrom_into():
                    b = bytearray(b"\0"*100)
                    count, addr = s.recvfrom_into(b)
                    return b[:count]

                # (name, method, whether to expect success, *args)
                send_methods = [
                    ('send', s.send, True, []),
                    ('sendto', s.sendto, False, ["some.address"]),
                    ('sendall', s.sendall, True, []),
                ]
                recv_methods = [
                    ('recv', s.recv, True, []),
                    ('recvfrom', s.recvfrom, False, ["some.address"]),
                    ('recv_into', _recv_into, True, []),
                    ('recvfrom_into', _recvfrom_into, False, []),
                ]
                data_prefix = "PREFIX_"

                for meth_name, send_meth, expect_success, args in send_methods:
                    indata = (data_prefix + meth_name).encode('ascii')
                    try:
                        send_meth(indata, *args)
                        outdata = s.read()
                        if outdata != indata.lower():
                            self.fail(
                                "While sending with <<{name:s}>> bad data "
                                "<<{outdata:r}>> ({nout:d}) received; "
                                "expected <<{indata:r}>> ({nin:d})\n".format(
                                    name=meth_name, outdata=outdata[:20],
                                    nout=len(outdata),
                                    indata=indata[:20], nin=len(indata)
                                )
                            )
                    except ValueError as e:
                        if expect_success:
                            self.fail(
                                "Failed to send with method <<{name:s}>>; "
                                "expected to succeed.\n".format(name=meth_name)
                            )
                        if not str(e).startswith(meth_name):
                            self.fail(
                                "Method <<{name:s}>> failed with unexpected "
                                "exception message: {exp:s}\n".format(
                                    name=meth_name, exp=e
                                )
                            )

                for meth_name, recv_meth, expect_success, args in recv_methods:
                    indata = (data_prefix + meth_name).encode('ascii')
                    try:
                        s.send(indata)
                        outdata = recv_meth(*args)
                        if outdata != indata.lower():
                            self.fail(
                                "While receiving with <<{name:s}>> bad data "
                                "<<{outdata:r}>> ({nout:d}) received; "
                                "expected <<{indata:r}>> ({nin:d})\n".format(
                                    name=meth_name, outdata=outdata[:20],
                                    nout=len(outdata),
                                    indata=indata[:20], nin=len(indata)
                                )
                            )
                    except ValueError as e:
                        if expect_success:
                            self.fail(
                                "Failed to receive with method <<{name:s}>>; "
                                "expected to succeed.\n".format(name=meth_name)
                            )
                        if not str(e).startswith(meth_name):
                            self.fail(
                                "Method <<{name:s}>> failed with unexpected "
                                "exception message: {exp:s}\n".format(
                                    name=meth_name, exp=e
                                )
                            )
                        # consume data
                        s.read()

                s.write(b"over\n")
                s.close()
            finally:
                server.stop()
                server.join()

        def test_handshake_timeout(self):
            # Issue #5103: SSL handshake must respect the socket timeout
            server = socket.socket(socket.AF_INET)
            host = "127.0.0.1"
            port = support.bind_port(server)
            started = threading.Event()
            finish = False

            def serve():
                server.listen(5)
                started.set()
                conns = []
                while not finish:
                    r, w, e = select.select([server], [], [], 0.1)
                    if server in r:
                        # Let the socket hang around rather than having
                        # it closed by garbage collection.
                        conns.append(server.accept()[0])

            t = threading.Thread(target=serve)
            t.start()
            started.wait()

            try:
                try:
                    c = socket.socket(socket.AF_INET)
                    c.settimeout(0.2)
                    c.connect((host, port))
                    # Will attempt handshake and time out
                    self.assertRaisesRegexp(ssl.SSLError, "timed out",
                                            ssl.wrap_socket, c)
                finally:
                    c.close()
                try:
                    c = socket.socket(socket.AF_INET)
                    c = ssl.wrap_socket(c)
                    c.settimeout(0.2)
                    # Will attempt handshake and time out
                    self.assertRaisesRegexp(ssl.SSLError, "timed out",
                                            c.connect, (host, port))
                finally:
                    c.close()
            finally:
                finish = True
                t.join()
                server.close()


def test_main(verbose=False):
    if skip_expected:
        raise unittest.SkipTest("No SSL support")

    if support.verbose:
        plats = {
            'Linux': platform.linux_distribution,
            'Mac': platform.mac_ver,
            'Windows': platform.win32_ver,
        }
        for name, func in plats.items():
            plat = func()
            if plat and plat[0]:
                plat = '%s %r' % (name, plat)
                break
        else:
            plat = repr(platform.platform())
        print("test_ssl: testing with %r %r" %
            (ssl.OPENSSL_VERSION, ssl.OPENSSL_VERSION_INFO))
        print("          under %s" % plat)

    for filename in [
        CERTFILE, SVN_PYTHON_ORG_ROOT_CERT, BYTES_CERTFILE,
        ONLYCERT, ONLYKEY, BYTES_ONLYCERT, BYTES_ONLYKEY,
        BADCERT, BADKEY, EMPTYCERT]:
        if not os.path.exists(filename):
            raise support.TestFailed("Can't read certificate file %r" % filename)

    tests = [ContextTests, BasicSocketTests]

    if support.is_resource_enabled('network'):
        tests.append(NetworkedTests)

    if _have_threads:
        thread_info = support.threading_setup()
        if thread_info and support.is_resource_enabled('network'):
            tests.append(ThreadedTests)

    try:
        support.run_unittest(*tests)
    finally:
        if _have_threads:
            support.threading_cleanup(*thread_info)

if __name__ == "__main__":
    test_main()