paramiko/tests/test_transport.py

# Copyright (C) 2003-2007  Robey Pointer <robey@lag.net>
#
# This file is part of paramiko.
#
# Paramiko is free software; you can redistribute it and/or modify it under the
# terms of the GNU Lesser General Public License as published by the Free
# Software Foundation; either version 2.1 of the License, or (at your option)
# any later version.
#
# Paramiko is distrubuted in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
# A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with Paramiko; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.

"""
Some unit tests for the ssh2 protocol in Transport.
"""

from binascii import hexlify, unhexlify
import select
import socket
import sys
import time
import threading
import unittest

from paramiko import Transport, SecurityOptions, ServerInterface, RSAKey, DSSKey, \
    SSHException, BadAuthenticationType, InteractiveQuery, ChannelException
from paramiko import AUTH_FAILED, AUTH_PARTIALLY_SUCCESSFUL, AUTH_SUCCESSFUL
from paramiko import OPEN_SUCCEEDED, OPEN_FAILED_ADMINISTRATIVELY_PROHIBITED
from loop import LoopSocket


class NullServer (ServerInterface):
    paranoid_did_password = False
    paranoid_did_public_key = False
    paranoid_key = DSSKey.from_private_key_file('tests/test_dss.key')
    
    def get_allowed_auths(self, username):
        if username == 'slowdive':
            return 'publickey,password'
        if username == 'paranoid':
            if not self.paranoid_did_password and not self.paranoid_did_public_key:
                return 'publickey,password'
            elif self.paranoid_did_password:
                return 'publickey'
            else:
                return 'password'
        if username == 'commie':
            return 'keyboard-interactive'
        return 'publickey'

    def check_auth_password(self, username, password):
        if (username == 'slowdive') and (password == 'pygmalion'):
            return AUTH_SUCCESSFUL
        if (username == 'paranoid') and (password == 'paranoid'):
            # 2-part auth (even openssh doesn't support this)
            self.paranoid_did_password = True
            if self.paranoid_did_public_key:
                return AUTH_SUCCESSFUL
            return AUTH_PARTIALLY_SUCCESSFUL
        return AUTH_FAILED

    def check_auth_publickey(self, username, key):
        if (username == 'paranoid') and (key == self.paranoid_key):
            # 2-part auth
            self.paranoid_did_public_key = True
            if self.paranoid_did_password:
                return AUTH_SUCCESSFUL
            return AUTH_PARTIALLY_SUCCESSFUL
        return AUTH_FAILED
    
    def check_auth_interactive(self, username, submethods):
        if username == 'commie':
            self.username = username
            return InteractiveQuery('password', 'Please enter a password.', ('Password', False))
        return AUTH_FAILED
    
    def check_auth_interactive_response(self, responses):
        if self.username == 'commie':
            if (len(responses) == 1) and (responses[0] == 'cat'):
                return AUTH_SUCCESSFUL
        return AUTH_FAILED

    def check_channel_request(self, kind, chanid):
        if kind == 'bogus':
            return OPEN_FAILED_ADMINISTRATIVELY_PROHIBITED
        return OPEN_SUCCEEDED

    def check_channel_exec_request(self, channel, command):
        if command != 'yes':
            return False
        return True

    def check_channel_shell_request(self, channel):
        return True
    
    def check_global_request(self, kind, msg):
        self._global_request = kind
        return False
    
    def check_channel_x11_request(self, channel, single_connection, auth_protocol, auth_cookie, screen_number):
        self._x11_single_connection = single_connection
        self._x11_auth_protocol = auth_protocol
        self._x11_auth_cookie = auth_cookie
        self._x11_screen_number = screen_number
        return True
    
    def check_port_forward_request(self, addr, port):
        self._listen = socket.socket()
        self._listen.listen(1)
        return self._listen.getsockname()[1]
    
    def cancel_port_forward_request(self, addr, port):
        self._listen.close()
        self._listen = None


class TransportTest (unittest.TestCase):

    def setUp(self):
        self.socks = LoopSocket()
        self.sockc = LoopSocket()
        self.sockc.link(self.socks)
        self.tc = Transport(self.sockc)
        self.ts = Transport(self.socks)

    def tearDown(self):
        self.tc.close()
        self.ts.close()
        self.socks.close()
        self.sockc.close()

    def setup_test_server(self):
        host_key = RSAKey.from_private_key_file('tests/test_rsa.key')
        public_host_key = RSAKey(data=str(host_key))
        self.ts.add_server_key(host_key)
        event = threading.Event()
        self.server = NullServer()
        self.assert_(not event.isSet())
        self.ts.start_server(event, self.server)
        self.tc.connect(hostkey=public_host_key)
        self.tc.auth_password(username='slowdive', password='pygmalion')
        event.wait(1.0)
        self.assert_(event.isSet())
        self.assert_(self.ts.is_active())

    def test_1_security_options(self):
        o = self.tc.get_security_options()
        self.assertEquals(type(o), SecurityOptions)
        self.assert_(('aes256-cbc', 'blowfish-cbc') != o.ciphers)
        o.ciphers = ('aes256-cbc', 'blowfish-cbc')
        self.assertEquals(('aes256-cbc', 'blowfish-cbc'), o.ciphers)
        try:
            o.ciphers = ('aes256-cbc', 'made-up-cipher')
            self.assert_(False)
        except ValueError:
            pass
        try:
            o.ciphers = 23
            self.assert_(False)
        except TypeError:
            pass
            
    def test_2_compute_key(self):
        self.tc.K = 123281095979686581523377256114209720774539068973101330872763622971399429481072519713536292772709507296759612401802191955568143056534122385270077606457721553469730659233569339356140085284052436697480759510519672848743794433460113118986816826624865291116513647975790797391795651716378444844877749505443714557929L
        self.tc.H = unhexlify('0C8307CDE6856FF30BA93684EB0F04C2520E9ED3')
        self.tc.session_id = self.tc.H
        key = self.tc._compute_key('C', 32)
        self.assertEquals('207E66594CA87C44ECCBA3B3CD39FDDB378E6FDB0F97C54B2AA0CFBF900CD995',
                          hexlify(key).upper())

    def test_3_simple(self):
        """
        verify that we can establish an ssh link with ourselves across the
        loopback sockets.  this is hardly "simple" but it's simpler than the
        later tests. :)
        """
        host_key = RSAKey.from_private_key_file('tests/test_rsa.key')
        public_host_key = RSAKey(data=str(host_key))
        self.ts.add_server_key(host_key)
        event = threading.Event()
        server = NullServer()
        self.assert_(not event.isSet())
        self.assertEquals(None, self.tc.get_username())
        self.assertEquals(None, self.ts.get_username())
        self.assertEquals(False, self.tc.is_authenticated())
        self.assertEquals(False, self.ts.is_authenticated())
        self.ts.start_server(event, server)
        self.tc.connect(hostkey=public_host_key,
                        username='slowdive', password='pygmalion')
        event.wait(1.0)
        self.assert_(event.isSet())
        self.assert_(self.ts.is_active())
        self.assertEquals('slowdive', self.tc.get_username())
        self.assertEquals('slowdive', self.ts.get_username())
        self.assertEquals(True, self.tc.is_authenticated())
        self.assertEquals(True, self.ts.is_authenticated())

    def test_4_special(self):
        """
        verify that the client can demand odd handshake settings, and can
        renegotiate keys in mid-stream.
        """
        host_key = RSAKey.from_private_key_file('tests/test_rsa.key')
        public_host_key = RSAKey(data=str(host_key))
        self.ts.add_server_key(host_key)
        event = threading.Event()
        server = NullServer()
        self.assert_(not event.isSet())
        self.ts.start_server(event, server)
        options = self.tc.get_security_options()
        options.ciphers = ('aes256-cbc',)
        options.digests = ('hmac-md5-96',)
        self.tc.connect(hostkey=public_host_key,
                        username='slowdive', password='pygmalion')
        event.wait(1.0)
        self.assert_(event.isSet())
        self.assert_(self.ts.is_active())
        self.assertEquals('aes256-cbc', self.tc.local_cipher)
        self.assertEquals('aes256-cbc', self.tc.remote_cipher)
        self.assertEquals(12, self.tc.packetizer.get_mac_size_out())
        self.assertEquals(12, self.tc.packetizer.get_mac_size_in())
        
        self.tc.send_ignore(1024)
        self.tc.renegotiate_keys()
        self.ts.send_ignore(1024)

    def test_5_keepalive(self):
        """
        verify that the keepalive will be sent.
        """
        self.tc.set_hexdump(True)
        
        host_key = RSAKey.from_private_key_file('tests/test_rsa.key')
        public_host_key = RSAKey(data=str(host_key))
        self.ts.add_server_key(host_key)
        event = threading.Event()
        server = NullServer()
        self.assert_(not event.isSet())
        self.ts.start_server(event, server)
        self.tc.connect(hostkey=public_host_key,
                        username='slowdive', password='pygmalion')
        event.wait(1.0)
        self.assert_(event.isSet())
        self.assert_(self.ts.is_active())
        
        self.assertEquals(None, getattr(server, '_global_request', None))
        self.tc.set_keepalive(1)
        time.sleep(2)
        self.assertEquals('keepalive@lag.net', server._global_request)
        
    def test_6_bad_auth_type(self):
        """
        verify that we get the right exception when an unsupported auth
        type is requested.
        """
        host_key = RSAKey.from_private_key_file('tests/test_rsa.key')
        public_host_key = RSAKey(data=str(host_key))
        self.ts.add_server_key(host_key)
        event = threading.Event()
        server = NullServer()
        self.assert_(not event.isSet())
        self.ts.start_server(event, server)
        try:
            self.tc.connect(hostkey=public_host_key,
                            username='unknown', password='error')
            self.assert_(False)
        except:
            etype, evalue, etb = sys.exc_info()
            self.assertEquals(BadAuthenticationType, etype)
            self.assertEquals(['publickey'], evalue.allowed_types)

    def test_7_bad_password(self):
        """
        verify that a bad password gets the right exception, and that a retry
        with the right password works.
        """
        host_key = RSAKey.from_private_key_file('tests/test_rsa.key')
        public_host_key = RSAKey(data=str(host_key))
        self.ts.add_server_key(host_key)
        event = threading.Event()
        server = NullServer()
        self.assert_(not event.isSet())
        self.ts.start_server(event, server)
        self.tc.ultra_debug = True
        self.tc.connect(hostkey=public_host_key)
        try:
            self.tc.auth_password(username='slowdive', password='error')
            self.assert_(False)
        except:
            etype, evalue, etb = sys.exc_info()
            self.assert_(issubclass(etype, SSHException))
        self.tc.auth_password(username='slowdive', password='pygmalion')
        event.wait(1.0)
        self.assert_(event.isSet())
        self.assert_(self.ts.is_active())
    
    def test_8_multipart_auth(self):
        """
        verify that multipart auth works.
        """
        host_key = RSAKey.from_private_key_file('tests/test_rsa.key')
        public_host_key = RSAKey(data=str(host_key))
        self.ts.add_server_key(host_key)
        event = threading.Event()
        server = NullServer()
        self.assert_(not event.isSet())
        self.ts.start_server(event, server)
        self.tc.ultra_debug = True
        self.tc.connect(hostkey=public_host_key)
        remain = self.tc.auth_password(username='paranoid', password='paranoid')
        self.assertEquals(['publickey'], remain)
        key = DSSKey.from_private_key_file('tests/test_dss.key')
        remain = self.tc.auth_publickey(username='paranoid', key=key)
        self.assertEquals([], remain)
        event.wait(1.0)
        self.assert_(event.isSet())
        self.assert_(self.ts.is_active())

    def test_9_interactive_auth(self):
        """
        verify keyboard-interactive auth works.
        """
        host_key = RSAKey.from_private_key_file('tests/test_rsa.key')
        public_host_key = RSAKey(data=str(host_key))
        self.ts.add_server_key(host_key)
        event = threading.Event()
        server = NullServer()
        self.assert_(not event.isSet())
        self.ts.start_server(event, server)
        self.tc.ultra_debug = True
        self.tc.connect(hostkey=public_host_key)

        def handler(title, instructions, prompts):
            self.got_title = title
            self.got_instructions = instructions
            self.got_prompts = prompts
            return ['cat']
        remain = self.tc.auth_interactive('commie', handler)
        self.assertEquals(self.got_title, 'password')
        self.assertEquals(self.got_prompts, [('Password', False)])
        self.assertEquals([], remain)
        event.wait(1.0)
        self.assert_(event.isSet())
        self.assert_(self.ts.is_active())
        
    def test_A_interactive_auth_fallback(self):
        """
        verify that a password auth attempt will fallback to "interactive"
        if password auth isn't supported but interactive is.
        """
        host_key = RSAKey.from_private_key_file('tests/test_rsa.key')
        public_host_key = RSAKey(data=str(host_key))
        self.ts.add_server_key(host_key)
        event = threading.Event()
        server = NullServer()
        self.assert_(not event.isSet())
        self.ts.start_server(event, server)
        self.tc.ultra_debug = True
        self.tc.connect(hostkey=public_host_key)
        remain = self.tc.auth_password('commie', 'cat')
        self.assertEquals([], remain)
        event.wait(1.0)
        self.assert_(event.isSet())
        self.assert_(self.ts.is_active())
            
    def test_B_exec_command(self):
        """
        verify that exec_command() does something reasonable.
        """
        self.setup_test_server()

        chan = self.tc.open_session()
        schan = self.ts.accept(1.0)
        try:
            chan.exec_command('no')
            self.assert_(False)
        except SSHException, x:
            pass
        
        chan = self.tc.open_session()
        chan.exec_command('yes')
        schan = self.ts.accept(1.0)
        schan.send('Hello there.\n')
        schan.send_stderr('This is on stderr.\n')
        schan.close()

        f = chan.makefile()
        self.assertEquals('Hello there.\n', f.readline())
        self.assertEquals('', f.readline())
        f = chan.makefile_stderr()
        self.assertEquals('This is on stderr.\n', f.readline())
        self.assertEquals('', f.readline())
        
        # now try it with combined stdout/stderr
        chan = self.tc.open_session()
        chan.exec_command('yes')
        schan = self.ts.accept(1.0)
        schan.send('Hello there.\n')
        schan.send_stderr('This is on stderr.\n')
        schan.close()

        chan.set_combine_stderr(True)        
        f = chan.makefile()
        self.assertEquals('Hello there.\n', f.readline())
        self.assertEquals('This is on stderr.\n', f.readline())
        self.assertEquals('', f.readline())

    def test_C_invoke_shell(self):
        """
        verify that invoke_shell() does something reasonable.
        """
        self.setup_test_server()
        chan = self.tc.open_session()
        chan.invoke_shell()
        schan = self.ts.accept(1.0)
        chan.send('communist j. cat\n')
        f = schan.makefile()
        self.assertEquals('communist j. cat\n', f.readline())
        chan.close()
        self.assertEquals('', f.readline())

    def test_D_channel_exception(self):
        """
        verify that ChannelException is thrown for a bad open-channel request.
        """
        self.setup_test_server()
        try:
            chan = self.tc.open_channel('bogus')
            self.fail('expected exception')
        except ChannelException, x:
            self.assert_(x.code == OPEN_FAILED_ADMINISTRATIVELY_PROHIBITED)

    def test_E_exit_status(self):
        """
        verify that get_exit_status() works.
        """
        self.setup_test_server()

        chan = self.tc.open_session()
        schan = self.ts.accept(1.0)
        chan.exec_command('yes')
        schan.send('Hello there.\n')
        # trigger an EOF
        schan.shutdown_read()
        schan.shutdown_write()
        schan.send_exit_status(23)
        schan.close()
        
        f = chan.makefile()
        self.assertEquals('Hello there.\n', f.readline())
        self.assertEquals('', f.readline())
        self.assertEquals(23, chan.recv_exit_status())
        chan.close()

    def test_F_select(self):
        """
        verify that select() on a channel works.
        """
        self.setup_test_server()
        chan = self.tc.open_session()
        chan.invoke_shell()
        schan = self.ts.accept(1.0)

        # nothing should be ready        
        r, w, e = select.select([chan], [], [], 0.1)
        self.assertEquals([], r)
        self.assertEquals([], w)
        self.assertEquals([], e)
        
        schan.send('hello\n')
        
        # something should be ready now (give it 1 second to appear)
        for i in range(10):
            r, w, e = select.select([chan], [], [], 0.1)
            if chan in r:
                break
            time.sleep(0.1)
        self.assertEquals([chan], r)
        self.assertEquals([], w)
        self.assertEquals([], e)

        self.assertEquals('hello\n', chan.recv(6))
        
        # and, should be dead again now
        r, w, e = select.select([chan], [], [], 0.1)
        self.assertEquals([], r)
        self.assertEquals([], w)
        self.assertEquals([], e)

        schan.close()
        
        # detect eof?
        for i in range(10):
            r, w, e = select.select([chan], [], [], 0.1)
            if chan in r:
                break
            time.sleep(0.1)
        self.assertEquals([chan], r)
        self.assertEquals([], w)
        self.assertEquals([], e)
        self.assertEquals('', chan.recv(16))
        
        # make sure the pipe is still open for now...
        p = chan._pipe
        self.assertEquals(False, p._closed)
        chan.close()
        # ...and now is closed.
        self.assertEquals(True, p._closed)
   
    def test_G_renegotiate(self):
        """
        verify that a transport can correctly renegotiate mid-stream.
        """
        self.setup_test_server()
        self.tc.packetizer.REKEY_BYTES = 16384
        chan = self.tc.open_session()
        chan.exec_command('yes')
        schan = self.ts.accept(1.0)

        self.assertEquals(self.tc.H, self.tc.session_id)
        for i in range(20):
            chan.send('x' * 1024)
        chan.close()
        
        # allow a few seconds for the rekeying to complete
        for i in xrange(50):
            if self.tc.H != self.tc.session_id:
                break
            time.sleep(0.1)
        self.assertNotEquals(self.tc.H, self.tc.session_id)

        schan.close()

    def test_H_compression(self):
        """
        verify that zlib compression is basically working.
        """
        host_key = RSAKey.from_private_key_file('tests/test_rsa.key')
        public_host_key = RSAKey(data=str(host_key))
        self.ts.add_server_key(host_key)
        self.ts.get_security_options().compression = ('zlib',)
        self.tc.get_security_options().compression = ('zlib',)
        event = threading.Event()
        server = NullServer()
        self.ts.start_server(event, server)
        self.tc.connect(hostkey=public_host_key,
                        username='slowdive', password='pygmalion')
        event.wait(1.0)
        self.assert_(event.isSet())
        self.assert_(self.ts.is_active())

        chan = self.tc.open_session()
        chan.exec_command('yes')
        schan = self.ts.accept(1.0)

        bytes = self.tc.packetizer._Packetizer__sent_bytes
        chan.send('x' * 1024)
        bytes2 = self.tc.packetizer._Packetizer__sent_bytes
        # tests show this is actually compressed to *52 bytes*!  including packet overhead!  nice!! :)
        self.assert_(bytes2 - bytes < 1024)
        self.assertEquals(52, bytes2 - bytes)

        chan.close()
        schan.close()

    def test_I_x11(self):
        """
        verify that an x11 port can be requested and opened.
        """
        self.setup_test_server()
        chan = self.tc.open_session()
        chan.exec_command('yes')
        schan = self.ts.accept(1.0)
        
        requested = []
        def handler(c, (addr, port)):
            requested.append((addr, port))
            self.tc._queue_incoming_channel(c)
            
        self.assertEquals(None, getattr(self.server, '_x11_screen_number', None))
        cookie = chan.request_x11(0, single_connection=True, handler=handler)
        self.assertEquals(0, self.server._x11_screen_number)
        self.assertEquals('MIT-MAGIC-COOKIE-1', self.server._x11_auth_protocol)
        self.assertEquals(cookie, self.server._x11_auth_cookie)
        self.assertEquals(True, self.server._x11_single_connection)
        
        x11_server = self.ts.open_x11_channel(('localhost', 6093))
        x11_client = self.tc.accept()
        self.assertEquals('localhost', requested[0][0])
        self.assertEquals(6093, requested[0][1])
        
        x11_server.send('hello')
        self.assertEquals('hello', x11_client.recv(5))
        
        x11_server.close()
        x11_client.close()
        chan.close()
        schan.close()

    def test_J_reverse_port_forwarding(self):
        """
        verify that a client can ask the server to open a reverse port for
        forwarding.
        """
        self.setup_test_server()
        chan = self.tc.open_session()
        chan.exec_command('yes')
        schan = self.ts.accept(1.0)
        
        requested = []
        def handler(c, (origin_addr, origin_port), (server_addr, server_port)):
            requested.append((origin_addr, origin_port))
            requested.append((server_addr, server_port))
            self.tc._queue_incoming_channel(c)
            
        port = self.tc.request_port_forward('', 0, handler)
        self.assertEquals(port, self.server._listen.getsockname()[1])

        cs = socket.socket()
        cs.connect(('', port))
        ss, _ = self.server._listen.accept()
        sch = self.ts.open_forwarded_tcpip_channel(ss.getpeername(), ss.getsockname())
        cch = self.tc.accept()
        
        sch.send('hello')
        self.assertEquals('hello', cch.recv(5))
        sch.close()
        cch.close()
        ss.close()
        cs.close()
        
        # now cancel it.
        self.tc.cancel_port_forward('', port)
        self.assertTrue(self.server._listen is None)

    def test_K_stderr_select(self):
        """
        verify that select() on a channel works even if only stderr is
        receiving data.
        """
        self.setup_test_server()
        chan = self.tc.open_session()
        chan.invoke_shell()
        schan = self.ts.accept(1.0)

        # nothing should be ready        
        r, w, e = select.select([chan], [], [], 0.1)
        self.assertEquals([], r)
        self.assertEquals([], w)
        self.assertEquals([], e)
        
        schan.send_stderr('hello\n')
        
        # something should be ready now (give it 1 second to appear)
        for i in range(10):
            r, w, e = select.select([chan], [], [], 0.1)
            if chan in r:
                break
            time.sleep(0.1)
        self.assertEquals([chan], r)
        self.assertEquals([], w)
        self.assertEquals([], e)

        self.assertEquals('hello\n', chan.recv_stderr(6))
        
        # and, should be dead again now
        r, w, e = select.select([chan], [], [], 0.1)
        self.assertEquals([], r)
        self.assertEquals([], w)
        self.assertEquals([], e)

        schan.close()
        chan.close()

    def test_L_send_ready(self):
        """
        verify that send_ready() indicates when a send would not block.
        """
        self.setup_test_server()
        chan = self.tc.open_session()
        chan.invoke_shell()
        schan = self.ts.accept(1.0)

        self.assertEquals(chan.send_ready(), True)
        total = 0
        K = '*' * 1024
        while total < 1024 * 1024:
            chan.send(K)
            total += len(K)
            if not chan.send_ready():
                break
        self.assert_(total < 1024 * 1024)

        schan.close()
        chan.close()
        self.assertEquals(chan.send_ready(), True)