Synnefo

#!/usr/bin/env python

# Copyright 2011 GRNET S.A. All rights reserved.

#

# Redistribution and use in source and binary forms, with or

# without modification, are permitted provided that the following

# conditions are met:

#

#   1. Redistributions of source code must retain the above

#      copyright notice, this list of conditions and the following

#      disclaimer.

#

#   2. Redistributions in binary form must reproduce the above

#      copyright notice, this list of conditions and the following

#      disclaimer in the documentation and/or other materials

#      provided with the distribution.

#

# THIS SOFTWARE IS PROVIDED BY GRNET S.A. ``AS IS'' AND ANY EXPRESS

# OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

# PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL GRNET S.A OR

# CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,

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# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF

# USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED

# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN

# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

# POSSIBILITY OF SUCH DAMAGE.

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# The views and conclusions contained in the software and

# documentation are those of the authors and should not be

# interpreted as representing official policies, either expressed

# or implied, of GRNET S.A.

"""Perform integration testing on a running Synnefo deployment"""

#import __main__

import datetime

import inspect

import logging

import os

import os.path

import paramiko

import prctl

import subprocess

import signal

import socket

import sys

import time

import tempfile

from base64 import b64encode

from IPy import IP

from multiprocessing import Process, Queue

from random import choice, randint

from optparse import OptionParser, OptionValueError

from kamaki.clients.compute import ComputeClient

from kamaki.clients.cyclades import CycladesClient

from kamaki.clients.image import ImageClient

from kamaki.clients.pithos import PithosClient

from kamaki.clients import ClientError

from vncauthproxy.d3des import generate_response as d3des_generate_response

# Use backported unittest functionality if Python < 2.7

try:

    import unittest2 as unittest

except ImportError:

    if sys.version_info < (2, 7):

        raise Exception("The unittest2 package is required for Python < 2.7")

    import unittest

# --------------------------------------------------------------------

# Global Variables

API = None

TOKEN = None

PLANKTON = None

PLANKTON_USER = None

PITHOS = None

PITHOS_USER = None

NO_IPV6 = None

DEFAULT_PLANKTON_USER = "images@okeanos.grnet.gr"

NOFAILFAST = None

VERBOSE = None

# A unique id identifying this test run

TEST_RUN_ID = datetime.datetime.strftime(datetime.datetime.now(),

                                         "%Y%m%d%H%M%S")

SNF_TEST_PREFIX = "snf-test-"

red = '\x1b[31m'

yellow = '\x1b[33m'

green = '\x1b[32m'

normal = '\x1b[0m'

# --------------------------------------------------------------------

# Global functions

def _ssh_execute(hostip, username, password, command):

    """Execute a command via ssh"""

    ssh = paramiko.SSHClient()

    ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())

    try:

        ssh.connect(hostip, username=username, password=password)

    except socket.error:

        raise AssertionError

    try:

        stdin, stdout, stderr = ssh.exec_command(command)

    except paramiko.SSHException:

        raise AssertionError

    status = stdout.channel.recv_exit_status()

    output = stdout.readlines()

    ssh.close()

    return output, status

# --------------------------------------------------------------------

# BurninTestReulst class

class BurninTestResult(unittest.TextTestResult):

    def addSuccess(self, test):

        super(BurninTestResult, self).addSuccess(test)

        if self.showAll:

            if hasattr(test, 'result_dict'):

                run_details = test.result_dict

                self.stream.write("\n")

                for i in run_details:

                    self.stream.write("%s : %s \n" % (i, run_details[i]))

                self.stream.write("\n")

        elif self.dots:

            self.stream.write('.')

            self.stream.flush()

    def addError(self, test, err):

        super(BurninTestResult, self).addError(test, err)

        if self.showAll:

            self.stream.writeln("ERROR")

            if hasattr(test, 'result_dict'):

                run_details = test.result_dict

                self.stream.write("\n")

                for i in run_details:

                    self.stream.write("%s : %s \n" % (i, run_details[i]))

                self.stream.write("\n")

        elif self.dots:

            self.stream.write('E')

            self.stream.flush()

    def addFailure(self, test, err):

        super(BurninTestResult, self).addFailure(test, err)

        if self.showAll:

            self.stream.writeln("FAIL")

            if hasattr(test, 'result_dict'):

                run_details = test.result_dict

                self.stream.write("\n")

                for i in run_details:

                    self.stream.write("%s : %s \n" % (i, run_details[i]))

                self.stream.write("\n")

        elif self.dots:

            self.stream.write('F')

            self.stream.flush()

# --------------------------------------------------------------------

# Format Results

class burninFormatter(logging.Formatter):

    err_fmt = red + "ERROR: %(msg)s" + normal

    dbg_fmt = green + "* %(msg)s" + normal

    info_fmt = "%(msg)s"

    def __init__(self, fmt="%(levelno)s: %(msg)s"):

        logging.Formatter.__init__(self, fmt)

    def format(self, record):

        format_orig = self._fmt

        # Replace the original format with one customized by logging level

        if record.levelno == 10:    # DEBUG

            self._fmt = burninFormatter.dbg_fmt

        elif record.levelno == 20:  # INFO

            self._fmt = burninFormatter.info_fmt

        elif record.levelno == 40:  # ERROR

            self._fmt = burninFormatter.err_fmt

        result = logging.Formatter.format(self, record)

        self._fmt = format_orig

        return result

log = logging.getLogger("burnin")

log.setLevel(logging.DEBUG)

handler = logging.StreamHandler()

handler.setFormatter(burninFormatter())

log.addHandler(handler)

# --------------------------------------------------------------------

# UnauthorizedTestCase class

class UnauthorizedTestCase(unittest.TestCase):

    """Test unauthorized access"""

    @classmethod

    def setUpClass(cls):

        cls.result_dict = dict()

    def test_unauthorized_access(self):

        """Test access without a valid token fails"""

        log.info("Authentication test")

        falseToken = '12345'

        c = ComputeClient(API, falseToken)

        with self.assertRaises(ClientError) as cm:

            c.list_servers()

            self.assertEqual(cm.exception.status, 401)

# --------------------------------------------------------------------

# This class gest replicated into Images TestCases dynamically

class ImagesTestCase(unittest.TestCase):

    """Test image lists for consistency"""

    @classmethod

    def setUpClass(cls):

        """Initialize kamaki, get (detailed) list of images"""

        log.info("Getting simple and detailed list of images")

        cls.client = ComputeClient(API, TOKEN)

        cls.plankton = ImageClient(PLANKTON, TOKEN)

        cls.images = cls.plankton.list_public()

        cls.dimages = cls.plankton.list_public(detail=True)

        cls.result_dict = dict()

        # Create temp directory and store it inside our class

        # XXX: In my machine /tmp has not enough space

        #      so use current directory to be sure.

        cls.temp_dir = tempfile.mkdtemp(dir=os.getcwd())

        cls.temp_image_name = \

            SNF_TEST_PREFIX + cls.imageid + ".diskdump"

    def test_001_list_images(self):

        """Test image list actually returns images"""

        self.assertGreater(len(self.images), 0)

    def test_002_list_images_detailed(self):

        """Test detailed image list is the same length as list"""

        self.assertEqual(len(self.dimages), len(self.images))

    def test_003_same_image_names(self):

        """Test detailed and simple image list contain same names"""

        names = sorted(map(lambda x: x["name"], self.images))

        dnames = sorted(map(lambda x: x["name"], self.dimages))

        self.assertEqual(names, dnames)

    def test_004_unique_image_names(self):

        """Test system images have unique names"""

        sys_images = filter(lambda x: x['owner'] == PLANKTON_USER,

                            self.dimages)

        names = sorted(map(lambda x: x["name"], sys_images))

        self.assertEqual(sorted(list(set(names))), names)

    def test_005_image_metadata(self):

        """Test every image has specific metadata defined"""

        keys = frozenset(["osfamily", "root_partition"])

        details = self.client.list_images(detail=True)

        for i in details:

            self.assertTrue(keys.issubset(i["metadata"]["values"].keys()))

    def test_006_download_image(self):

        """Download image from pithos+"""

        # Get image location

        image = filter(

            lambda x: x['id'] == self.imageid, self.dimages)[0]

        image_location = \

            image['location'].replace("://", " ").replace("/", " ").split()

        log.info("Download image, with owner %s\n\tcontainer %s, and name %s"

                 % (image_location[1], image_location[2], image_location[3]))

        pithos_client = PithosClient(PITHOS, TOKEN, image_location[1])

        pithos_client.container = image_location[2]

        temp_file = os.path.join(self.temp_dir, self.temp_image_name)

        with open(temp_file, "wb+") as f:

            pithos_client.download_object(image_location[3], f)

    def test_007_upload_image(self):

        """Upload and register image"""

        temp_file = os.path.join(self.temp_dir, self.temp_image_name)

        log.info("Upload image to pithos+")

        # Create container `images'

        pithos_client = PithosClient(PITHOS, TOKEN, PITHOS_USER)

        pithos_client.container = "images"

        pithos_client.container_put()

        with open(temp_file, "rb+") as f:

            pithos_client.upload_object(self.temp_image_name, f)

        log.info("Register image to plankton")

        location = "pithos://" + PITHOS_USER + \

            "/images/" + self.temp_image_name

        params = {'is_public': True}

        properties = {'OSFAMILY': "linux", 'ROOT_PARTITION': 1}

        self.plankton.register(self.temp_image_name, location,

                               params, properties)

# --------------------------------------------------------------------

# FlavorsTestCase class

class FlavorsTestCase(unittest.TestCase):

    """Test flavor lists for consistency"""

    @classmethod

    def setUpClass(cls):

        """Initialize kamaki, get (detailed) list of flavors"""

        log.info("Getting simple and detailed list of flavors")

        cls.client = ComputeClient(API, TOKEN)

        cls.flavors = cls.client.list_flavors()

        cls.dflavors = cls.client.list_flavors(detail=True)

        cls.result_dict = dict()

    def test_001_list_flavors(self):

        """Test flavor list actually returns flavors"""

        self.assertGreater(len(self.flavors), 0)

    def test_002_list_flavors_detailed(self):

        """Test detailed flavor list is the same length as list"""

        self.assertEquals(len(self.dflavors), len(self.flavors))

    def test_003_same_flavor_names(self):

        """Test detailed and simple flavor list contain same names"""

        names = sorted(map(lambda x: x["name"], self.flavors))

        dnames = sorted(map(lambda x: x["name"], self.dflavors))

        self.assertEqual(names, dnames)

    def test_004_unique_flavor_names(self):

        """Test flavors have unique names"""

        names = sorted(map(lambda x: x["name"], self.flavors))

        self.assertEqual(sorted(list(set(names))), names)

    def test_005_well_formed_flavor_names(self):

        """Test flavors have names of the form CxxRyyDzz

        Where xx is vCPU count, yy is RAM in MiB, zz is Disk in GiB

        """

        for f in self.dflavors:

            self.assertEqual("C%dR%dD%d" % (f["cpu"], f["ram"], f["disk"]),

                             f["name"],

                             "Flavor %s does not match its specs." % f["name"])

# --------------------------------------------------------------------

# ServersTestCase class

class ServersTestCase(unittest.TestCase):

    """Test server lists for consistency"""

    @classmethod

    def setUpClass(cls):

        """Initialize kamaki, get (detailed) list of servers"""

        log.info("Getting simple and detailed list of servers")

        cls.client = ComputeClient(API, TOKEN)

        cls.servers = cls.client.list_servers()

        cls.dservers = cls.client.list_servers(detail=True)

        cls.result_dict = dict()

    # def test_001_list_servers(self):

    #     """Test server list actually returns servers"""

    #     self.assertGreater(len(self.servers), 0)

    def test_002_list_servers_detailed(self):

        """Test detailed server list is the same length as list"""

        self.assertEqual(len(self.dservers), len(self.servers))

    def test_003_same_server_names(self):

        """Test detailed and simple flavor list contain same names"""

        names = sorted(map(lambda x: x["name"], self.servers))

        dnames = sorted(map(lambda x: x["name"], self.dservers))

        self.assertEqual(names, dnames)

# --------------------------------------------------------------------

# Pithos Test Cases

class PithosTestCase(unittest.TestCase):

    """Test pithos functionality"""

    @classmethod

    def setUpClass(cls):

        """Initialize kamaki, get list of containers"""

        log.info("Getting list of containers")

        cls.client = PithosClient(PITHOS, TOKEN, PITHOS_USER)

        cls.containers = cls.client.list_containers()

        cls.result_dict = dict()

    def test_001_list_containers(self):

        """Test container list actually returns containers"""

        self.assertGreater(len(self.containers), 0)

    def test_002_unique_containers(self):

        """Test if containers have unique names"""

        names = [n['name'] for n in self.containers]

        names = sorted(names)

        self.assertEqual(sorted(list(set(names))), names)

    def test_003_create_container(self):

        """Test create a container"""

        rand_num = randint(1000, 9999)

        rand_name = "%s%s" % (SNF_TEST_PREFIX, rand_num)

        names = [n['name'] for n in self.containers]

        while rand_name in names:

            rand_num = randint(1000, 9999)

            rand_name = "%s%s" % (SNF_TEST_PREFIX, rand_num)

        # Create container

        self.client.container = rand_name

        self.client.container_put()

        # Get list of containers

        new_containers = self.client.list_containers()

        new_container_names = [n['name'] for n in new_containers]

        self.assertIn(rand_name, new_container_names)

    def test_004_upload(self):

        """Test uploading something to pithos+"""

        # Create a tmp file

        with tempfile.TemporaryFile() as f:

            f.write("This is a temp file")

            f.seek(0, 0)

            # Where to save file

            self.client.upload_object("test.txt", f)

    def test_005_download(self):

        """Test download something from pithos+"""

        # Create tmp directory to save file

        tmp_dir = tempfile.mkdtemp()

        tmp_file = os.path.join(tmp_dir, "test.txt")

        with open(tmp_file, "wb+") as f:

            self.client.download_object("test.txt", f)

            # Read file

            f.seek(0, 0)

            content = f.read()

        # Remove files

        os.unlink(tmp_file)

        os.rmdir(tmp_dir)

        # Compare results

        self.assertEqual(content, "This is a temp file")

    def test_006_remove(self):

        """Test removing files and containers"""

        cont_name = self.client.container

        self.client.del_object("test.txt")

        self.client.purge_container()

        # List containers

        containers = self.client.list_containers()

        cont_names = [n['name'] for n in containers]

        self.assertNotIn(cont_name, cont_names)

# --------------------------------------------------------------------

# This class gets replicated into actual TestCases dynamically

class SpawnServerTestCase(unittest.TestCase):

    """Test scenario for server of the specified image"""

    @classmethod

    def setUpClass(cls):

        """Initialize a kamaki instance"""

        log.info("Spawning server for image `%s'" % cls.imagename)

        cls.client = ComputeClient(API, TOKEN)

        cls.cyclades = CycladesClient(API, TOKEN)

        cls.result_dict = dict()

    def _get_ipv4(self, server):

        """Get the public IPv4 of a server from the detailed server info"""

        nics = server["attachments"]["values"]

        for nic in nics:

            net_id = nic["network_id"]

            if self.cyclades.get_network_details(net_id)["public"]:

                public_addrs = nic["ipv4"]

        self.assertTrue(public_addrs is not None)

        return public_addrs

    def _get_ipv6(self, server):

        """Get the public IPv6 of a server from the detailed server info"""

        nics = server["attachments"]["values"]

        for nic in nics:

            net_id = nic["network_id"]

            if self.cyclades.get_network_details(net_id)["public"]:

                public_addrs = nic["ipv6"]

        self.assertTrue(public_addrs is not None)

        return public_addrs

    def _connect_loginname(self, os_value):

        """Return the login name for connections based on the server OS"""

        if os_value in ("Ubuntu", "Kubuntu", "Fedora"):

            return "user"

        elif os_value in ("windows", "windows_alpha1"):

            return "Administrator"

        else:

            return "root"

    def _verify_server_status(self, current_status, new_status):

        """Verify a server has switched to a specified status"""

        server = self.client.get_server_details(self.serverid)

        if server["status"] not in (current_status, new_status):

            return None  # Do not raise exception, return so the test fails

        self.assertEquals(server["status"], new_status)

    def _get_connected_tcp_socket(self, family, host, port):

        """Get a connected socket from the specified family to host:port"""

        sock = None

        for res in \

            socket.getaddrinfo(host, port, family, socket.SOCK_STREAM, 0,

                               socket.AI_PASSIVE):

            af, socktype, proto, canonname, sa = res

            try:

                sock = socket.socket(af, socktype, proto)

            except socket.error:

                sock = None

                continue

            try:

                sock.connect(sa)

            except socket.error:

                sock.close()

                sock = None

                continue

        self.assertIsNotNone(sock)

        return sock

    def _ping_once(self, ipv6, ip):

        """Test server responds to a single IPv4 or IPv6 ping"""

        cmd = "ping%s -c 2 -w 3 %s" % ("6" if ipv6 else "", ip)

        ping = subprocess.Popen(cmd, shell=True,

                                stdout=subprocess.PIPE, stderr=subprocess.PIPE)

        (stdout, stderr) = ping.communicate()

        ret = ping.wait()

        self.assertEquals(ret, 0)

    def _get_hostname_over_ssh(self, hostip, username, password):

        lines, status = _ssh_execute(

            hostip, username, password, "hostname")

        self.assertEqual(len(lines), 1)

        return lines[0]

    def _try_until_timeout_expires(self, warn_timeout, fail_timeout,

                                   opmsg, callable, *args, **kwargs):

        if warn_timeout == fail_timeout:

            warn_timeout = fail_timeout + 1

        warn_tmout = time.time() + warn_timeout

        fail_tmout = time.time() + fail_timeout

        while True:

            self.assertLess(time.time(), fail_tmout,

                            "operation `%s' timed out" % opmsg)

            if time.time() > warn_tmout:

                log.warning("Server %d: `%s' operation `%s' not done yet",

                            self.serverid, self.servername, opmsg)

            try:

                log.info("%s... " % opmsg)

                return callable(*args, **kwargs)

            except AssertionError:

                pass

            time.sleep(self.query_interval)

    def _insist_on_tcp_connection(self, family, host, port):

        familystr = {socket.AF_INET: "IPv4", socket.AF_INET6: "IPv6",

                     socket.AF_UNSPEC: "Unspecified-IPv4/6"}

        msg = "connect over %s to %s:%s" % \

              (familystr.get(family, "Unknown"), host, port)

        sock = self._try_until_timeout_expires(

            self.action_timeout, self.action_timeout,

            msg, self._get_connected_tcp_socket,

            family, host, port)

        return sock

    def _insist_on_status_transition(self, current_status, new_status,

                                     fail_timeout, warn_timeout=None):

        msg = "Server %d: `%s', waiting for %s -> %s" % \

              (self.serverid, self.servername, current_status, new_status)

        if warn_timeout is None:

            warn_timeout = fail_timeout

        self._try_until_timeout_expires(warn_timeout, fail_timeout,

                                        msg, self._verify_server_status,

                                        current_status, new_status)

        # Ensure the status is actually the expected one

        server = self.client.get_server_details(self.serverid)

        self.assertEquals(server["status"], new_status)

    def _insist_on_ssh_hostname(self, hostip, username, password):

        msg = "SSH to %s, as %s/%s" % (hostip, username, password)

        hostname = self._try_until_timeout_expires(

            self.action_timeout, self.action_timeout,

            msg, self._get_hostname_over_ssh,

            hostip, username, password)

        # The hostname must be of the form 'prefix-id'

        self.assertTrue(hostname.endswith("-%d\n" % self.serverid))

    def _check_file_through_ssh(self, hostip, username, password,

                                remotepath, content):

        msg = "Trying file injection through SSH to %s, as %s/%s" % \

            (hostip, username, password)

        log.info(msg)

        try:

            ssh = paramiko.SSHClient()

            ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())

            ssh.connect(hostip, username=username, password=password)

            ssh.close()

        except socket.error:

            raise AssertionError

        transport = paramiko.Transport((hostip, 22))

        transport.connect(username=username, password=password)

        localpath = '/tmp/' + SNF_TEST_PREFIX + 'injection'

        sftp = paramiko.SFTPClient.from_transport(transport)

        sftp.get(remotepath, localpath)

        sftp.close()

        transport.close()

        f = open(localpath)

        remote_content = b64encode(f.read())

        # Check if files are the same

        return (remote_content == content)

    def _skipIf(self, condition, msg):

        if condition:

            self.skipTest(msg)

    def test_001_submit_create_server(self):

        """Test submit create server request"""

        log.info("Submit new server request")

        server = self.client.create_server(self.servername, self.flavorid,

                                           self.imageid, self.personality)

        log.info("Server id: " + str(server["id"]))

        log.info("Server password: " + server["adminPass"])

        self.assertEqual(server["name"], self.servername)

        self.assertEqual(server["flavorRef"], self.flavorid)

        self.assertEqual(server["imageRef"], self.imageid)

        self.assertEqual(server["status"], "BUILD")

        # Update class attributes to reflect data on building server

        cls = type(self)

        cls.serverid = server["id"]

        cls.username = None

        cls.passwd = server["adminPass"]

        self.result_dict["Server ID"] = str(server["id"])

        self.result_dict["Password"] = str(server["adminPass"])

    def test_002a_server_is_building_in_list(self):

        """Test server is in BUILD state, in server list"""

        log.info("Server in BUILD state in server list")

        self.result_dict.clear()

        servers = self.client.list_servers(detail=True)

        servers = filter(lambda x: x["name"] == self.servername, servers)

        server = servers[0]

        self.assertEqual(server["name"], self.servername)

        self.assertEqual(server["flavorRef"], self.flavorid)

        self.assertEqual(server["imageRef"], self.imageid)

        self.assertEqual(server["status"], "BUILD")

    def test_002b_server_is_building_in_details(self):

        """Test server is in BUILD state, in details"""

        log.info("Server in BUILD state in details")

        server = self.client.get_server_details(self.serverid)

        self.assertEqual(server["name"], self.servername)

        self.assertEqual(server["flavorRef"], self.flavorid)

        self.assertEqual(server["imageRef"], self.imageid)

        self.assertEqual(server["status"], "BUILD")

    def test_002c_set_server_metadata(self):

        log.info("Creating server metadata")

        image = self.client.get_image_details(self.imageid)

        os_value = image["metadata"]["values"]["os"]

        users = image["metadata"]["values"].get("users", None)

        self.client.update_server_metadata(self.serverid, OS=os_value)

        userlist = users.split()

        # Determine the username to use for future connections

        # to this host

        cls = type(self)

        if "root" in userlist:

            cls.username = "root"

        elif users is None:

            cls.username = self._connect_loginname(os_value)

        else:

            cls.username = choice(userlist)

        self.assertIsNotNone(cls.username)

    def test_002d_verify_server_metadata(self):

        """Test server metadata keys are set based on image metadata"""

        log.info("Verifying image metadata")

        servermeta = self.client.get_server_metadata(self.serverid)

        imagemeta = self.client.get_image_metadata(self.imageid)

        self.assertEqual(servermeta["OS"], imagemeta["os"])

    def test_003_server_becomes_active(self):

        """Test server becomes ACTIVE"""

        log.info("Waiting for server to become ACTIVE")

        self._insist_on_status_transition(

            "BUILD", "ACTIVE", self.build_fail, self.build_warning)

    def test_003a_get_server_oob_console(self):

        """Test getting OOB server console over VNC

        Implementation of RFB protocol follows

        http://www.realvnc.com/docs/rfbproto.pdf.

        """

        console = self.cyclades.get_server_console(self.serverid)

        self.assertEquals(console['type'], "vnc")

        sock = self._insist_on_tcp_connection(

            socket.AF_INET, console["host"], console["port"])

        # Step 1. ProtocolVersion message (par. 6.1.1)

        version = sock.recv(1024)

        self.assertEquals(version, 'RFB 003.008\n')

        sock.send(version)

        # Step 2. Security (par 6.1.2): Only VNC Authentication supported

        sec = sock.recv(1024)

        self.assertEquals(list(sec), ['\x01', '\x02'])

        # Step 3. Request VNC Authentication (par 6.1.2)

        sock.send('\x02')

        # Step 4. Receive Challenge (par 6.2.2)

        challenge = sock.recv(1024)

        self.assertEquals(len(challenge), 16)