summaryrefslogtreecommitdiff
path: root/tests/test_sftp.py
blob: 993899ad4bef9a239b8f3dd5ddb1139ce3dd2774 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
# Copyright (C) 2003-2005 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 to make sure sftp works.

a real actual sftp server is contacted, and a new folder is created there to
do test file operations in (so no existing files will be harmed).
"""

import logging
import os
import random
import sys
import threading
import time
import unittest

import paramiko
from stub_sftp import StubServer, StubSFTPServer
from loop import LoopSocket

ARTICLE = '''
Insulin sensitivity and liver insulin receptor structure in ducks from two
genera

T. Constans, B. Chevalier, M. Derouet and J. Simon
Station de Recherches Avicoles, Institut National de la Recherche Agronomique,
Nouzilly, France.

Insulin sensitivity and liver insulin receptor structure were studied in
5-wk-old ducks from two genera (Muscovy and Pekin). In the fasting state, both
duck types were equally resistant to exogenous insulin compared with chicken.
Despite the low potency of duck insulin, the number of insulin receptors was
lower in Muscovy duck and similar in Pekin duck and chicken liver membranes.
After 125I-insulin cross-linking, the size of the alpha-subunit of the
receptors from the three species was 135,000. Wheat germ agglutinin-purified
receptors from the three species were contaminated by an active and unusual
adenosinetriphosphatase (ATPase) contaminant (highest activity in Muscovy
duck). Sequential purification of solubilized receptor from both duck types on
lentil and then wheat germ agglutinin lectins led to a fraction of receptors
very poor in ATPase activity that exhibited a beta-subunit size (95,000) and
tyrosine kinase activity similar to those of ATPase-free chicken insulin
receptors. Therefore the ducks from the two genera exhibit an alpha-beta-
structure for liver insulin receptors and a clear difference in the number of
liver insulin receptors. Their sensitivity to insulin is, however, similarly
decreased compared with chicken.
'''

FOLDER = os.environ.get('TEST_FOLDER', 'temp-testing000')

sftp = None
tc = None
g_big_file_test = True


class SFTPTest (unittest.TestCase):

    def init(hostname, username, keyfile, passwd):
        global sftp, tc
        
        t = paramiko.Transport(hostname)
        tc = t
        try:
            key = paramiko.RSAKey.from_private_key_file(keyfile, passwd)
        except paramiko.PasswordRequiredException:
            sys.stderr.write('\n\nparamiko.RSAKey.from_private_key_file REQUIRES PASSWORD.\n')
            sys.stderr.write('You have two options:\n')
            sys.stderr.write('* Use the "-K" option to point to a different (non-password-protected)\n')
            sys.stderr.write('  private key file.\n')
            sys.stderr.write('* Use the "-P" option to provide the password needed to unlock this private\n')
            sys.stderr.write('  key.\n')
            sys.stderr.write('\n')
            sys.exit(1)
        try:
            t.connect(username=username, pkey=key)
        except paramiko.SSHException:
            t.close()
            sys.stderr.write('\n\nparamiko.Transport.connect FAILED.\n')
            sys.stderr.write('There are several possible reasons why it might fail so quickly:\n\n')
            sys.stderr.write('* The host to connect to (%s) is not a valid SSH server.\n' % hostname)
            sys.stderr.write('  (Use the "-H" option to change the host.)\n')
            sys.stderr.write('* The username to auth as (%s) is invalid.\n' % username)
            sys.stderr.write('  (Use the "-U" option to change the username.)\n')
            sys.stderr.write('* The private key given (%s) is not accepted by the server.\n' % keyfile)
            sys.stderr.write('  (Use the "-K" option to provide a different key file.)\n')
            sys.stderr.write('\n')
            sys.exit(1)
        sftp = paramiko.SFTP.from_transport(t)
    init = staticmethod(init)

    def init_loopback():
        global sftp, tc

        socks = LoopSocket()
        sockc = LoopSocket()
        sockc.link(socks)
        tc = paramiko.Transport(sockc)
        ts = paramiko.Transport(socks)

        host_key = paramiko.RSAKey.from_private_key_file('tests/test_rsa.key')
        ts.add_server_key(host_key)
        event = threading.Event()
        server = StubServer()
        ts.set_subsystem_handler('sftp', paramiko.SFTPServer, StubSFTPServer)
        ts.start_server(event, server)
        tc.connect(username='slowdive', password='pygmalion')
        event.wait(1.0)

        sftp = paramiko.SFTP.from_transport(tc)
    init_loopback = staticmethod(init_loopback)

    def set_big_file_test(onoff):
        global g_big_file_test
        g_big_file_test = onoff
    set_big_file_test = staticmethod(set_big_file_test)
        
    def setUp(self):
        global FOLDER
        for i in xrange(1000):
            FOLDER = FOLDER[:-3] + '%03d' % i
            try:
                sftp.mkdir(FOLDER)
                break
            except (IOError, OSError):
                pass

    def tearDown(self):
        sftp.rmdir(FOLDER)

    def test_1_file(self):
        """
        verify that we can create a file.
        """
        f = sftp.open(FOLDER + '/test', 'w')
        try:
            self.assertEqual(f.stat().st_size, 0)
            f.close()
        finally:
            sftp.remove(FOLDER + '/test')

    def test_2_close(self):
        """
        verify that closing the sftp session doesn't do anything bad, and that
        a new one can be opened.
        """
        global sftp
        sftp.close()
        try:
            sftp.open(FOLDER + '/test2', 'w')
            self.fail('expected exception')
        except:
            pass
        sftp = paramiko.SFTP.from_transport(tc)

    def test_3_write(self):
        """
        verify that a file can be created and written, and the size is correct.
        """
        f = sftp.open(FOLDER + '/duck.txt', 'w')
        try:
            f.write(ARTICLE)
            f.close()
            self.assertEqual(sftp.stat(FOLDER + '/duck.txt').st_size, 1483)
        finally:
            sftp.remove(FOLDER + '/duck.txt')

    def test_4_append(self):
        """
        verify that a file can be opened for append, and tell() still works.
        """
        f = sftp.open(FOLDER + '/append.txt', 'w')
        try:
            f.write('first line\nsecond line\n')
            self.assertEqual(f.tell(), 23)
            f.close()

            f = sftp.open(FOLDER + '/append.txt', 'a+')
            f.write('third line!!!\n')
            self.assertEqual(f.tell(), 37)
            self.assertEqual(f.stat().st_size, 37)
            f.seek(-26, f.SEEK_CUR)
            self.assertEqual(f.readline(), 'second line\n')
            f.close()
        finally:
            sftp.remove(FOLDER + '/append.txt')
        
    def test_5_rename(self):
        """
        verify that renaming a file works.
        """
        f = sftp.open(FOLDER + '/first.txt', 'w')
        try:
            f.write('content!\n');
            f.close()
            sftp.rename(FOLDER + '/first.txt', FOLDER + '/second.txt')
            try:
                f = sftp.open(FOLDER + '/first.txt', 'r')
                self.assert_(False, 'no exception on reading nonexistent file')
            except IOError:
                pass
            f = sftp.open(FOLDER + '/second.txt', 'r')
            f.seek(-6, f.SEEK_END)
            self.assertEqual(f.read(4), 'tent')
            f.close()
        finally:
            try:
                sftp.remove(FOLDER + '/first.txt')
            except:
                pass
            try:
                sftp.remove(FOLDER + '/second.txt')
            except:
                pass

    def test_6_folder(self):
        """
        create a temporary folder, verify that we can create a file in it, then
        remove the folder and verify that we can't create a file in it anymore.
        """
        sftp.mkdir(FOLDER + '/subfolder')
        f = sftp.open(FOLDER + '/subfolder/test', 'w')
        f.close()
        sftp.remove(FOLDER + '/subfolder/test')
        sftp.rmdir(FOLDER + '/subfolder')
        try:
            f = sftp.open(FOLDER + '/subfolder/test')
            # shouldn't be able to create that file
            self.assert_(False, 'no exception at dummy file creation')
        except IOError:
            pass

    def test_7_listdir(self):
        """
        verify that a folder can be created, a bunch of files can be placed in it,
        and those files show up in sftp.listdir.
        """
        try:
            f = sftp.open(FOLDER + '/duck.txt', 'w')
            f.close()

            f = sftp.open(FOLDER + '/fish.txt', 'w')
            f.close()

            f = sftp.open(FOLDER + '/tertiary.py', 'w')
            f.close()

            x = sftp.listdir(FOLDER)
            self.assertEqual(len(x), 3)
            self.assert_('duck.txt' in x)
            self.assert_('fish.txt' in x)
            self.assert_('tertiary.py' in x)
            self.assert_('random' not in x)
        finally:
            sftp.remove(FOLDER + '/duck.txt')
            sftp.remove(FOLDER + '/fish.txt')
            sftp.remove(FOLDER + '/tertiary.py')

    def test_8_setstat(self):
        """
        verify that the setstat functions (chown, chmod, utime) work.
        """
        f = sftp.open(FOLDER + '/special', 'w')
        try:
            f.close()

            stat = sftp.stat(FOLDER + '/special')
            sftp.chmod(FOLDER + '/special', (stat.st_mode & ~0777) | 0600)
            self.assertEqual(sftp.stat(FOLDER + '/special').st_mode & 0777, 0600)

            mtime = stat.st_mtime - 3600
            atime = stat.st_atime - 1800
            sftp.utime(FOLDER + '/special', (atime, mtime))
            nstat = sftp.stat(FOLDER + '/special')
            self.assertEqual(nstat.st_mtime, mtime)
            self.assertEqual(nstat.st_atime, atime)

            # can't really test chown, since we'd have to know a valid uid.
        finally:
            sftp.remove(FOLDER + '/special')

    def test_9_readline_seek(self):
        """
        create a text file and write a bunch of text into it.  then count the lines
        in the file, and seek around to retreive particular lines.  this should
        verify that read buffering and 'tell' work well together, and that read
        buffering is reset on 'seek'.
        """
        try:
            f = sftp.open(FOLDER + '/duck.txt', 'w')
            f.write(ARTICLE)
            f.close()

            f = sftp.open(FOLDER + '/duck.txt', 'r+')
            line_number = 0
            loc = 0
            pos_list = []
            for line in f:
                line_number += 1
                pos_list.append(loc)
                loc = f.tell()
            f.seek(pos_list[6], f.SEEK_SET)
            self.assertEqual(f.readline(), 'Nouzilly, France.\n')
            f.seek(pos_list[17], f.SEEK_SET)
            self.assertEqual(f.readline()[:4], 'duck')
            f.seek(pos_list[10], f.SEEK_SET)
            self.assertEqual(f.readline(), 'duck types were equally resistant to exogenous insulin compared with chicken.\n')
            f.close()
        finally:
            sftp.remove(FOLDER + '/duck.txt')

    def test_A_write_seek(self):
        """
        create a text file, seek back and change part of it, and verify that the
        changes worked.
        """
        f = sftp.open(FOLDER + '/testing.txt', 'w')
        try:
            f.write('hello kitty.\n')
            f.seek(-5, f.SEEK_CUR)
            f.write('dd')
            f.close()

            self.assertEqual(sftp.stat(FOLDER + '/testing.txt').st_size, 13)
            f = sftp.open(FOLDER + '/testing.txt', 'r')
            data = f.read(20)
            f.close()
            self.assertEqual(data, 'hello kiddy.\n')
        finally:
            sftp.remove(FOLDER + '/testing.txt')

    def test_B_symlink(self):
        """
        create a symlink and then check that lstat doesn't follow it.
        """
        f = sftp.open(FOLDER + '/original.txt', 'w')
        try:
            f.write('original\n')
            f.close()
            sftp.symlink('original.txt', FOLDER + '/link.txt')
            self.assertEqual(sftp.readlink(FOLDER + '/link.txt'), 'original.txt')

            f = sftp.open(FOLDER + '/link.txt', 'r')
            self.assertEqual(f.readlines(), [ 'original\n' ])
            f.close()

            cwd = sftp.normalize('.')
            if cwd[-1] == '/':
                cwd = cwd[:-1]
            abs_path = cwd + '/' + FOLDER + '/original.txt'
            sftp.symlink(abs_path, FOLDER + '/link2.txt')
            self.assertEqual(abs_path, sftp.readlink(FOLDER + '/link2.txt'))

            self.assertEqual(sftp.lstat(FOLDER + '/link.txt').st_size, 12)
            self.assertEqual(sftp.stat(FOLDER + '/link.txt').st_size, 9)
            # the sftp server may be hiding extra path members from us, so the
            # length may be longer than we expect:
            self.assert_(sftp.lstat(FOLDER + '/link2.txt').st_size >= len(abs_path))
            self.assertEqual(sftp.stat(FOLDER + '/link2.txt').st_size, 9)
            self.assertEqual(sftp.stat(FOLDER + '/original.txt').st_size, 9)
        finally:
            try:
                sftp.remove(FOLDER + '/link.txt')
            except:
                pass
            try:
                sftp.remove(FOLDER + '/link2.txt')
            except:
                pass
            try:
                sftp.remove(FOLDER + '/original.txt')
            except:
                pass

    def test_C_flush_seek(self):
        """
        verify that buffered writes are automatically flushed on seek.
        """
        f = sftp.open(FOLDER + '/happy.txt', 'w', 1)
        try:
            f.write('full line.\n')
            f.write('partial')
            f.seek(9, f.SEEK_SET)
            f.write('?\n')
            f.close()

            f = sftp.open(FOLDER + '/happy.txt', 'r')
            self.assertEqual(f.readline(), 'full line?\n')
            self.assertEqual(f.read(7), 'partial')
            f.close()
        finally:
            try:
                sftp.remove(FOLDER + '/happy.txt')
            except:
                pass

    def test_D_lots_of_files(self):
        """
        create a bunch of files over the same session.
        """
        global g_big_file_test
        if not g_big_file_test:
            return
        numfiles = 100
        try:
            for i in range(numfiles):
                f = sftp.open('%s/file%d.txt' % (FOLDER, i), 'w', 1)
                f.write('this is file #%d.\n' % i)
                f.close()
                sftp.chmod('%s/file%d.txt' % (FOLDER, i), 0660)

            # now make sure every file is there, by creating a list of filenmes
            # and reading them in random order.
            numlist = range(numfiles)
            while len(numlist) > 0:
                r = numlist[random.randint(0, len(numlist) - 1)]
                f = sftp.open('%s/file%d.txt' % (FOLDER, r))
                self.assertEqual(f.readline(), 'this is file #%d.\n' % r)
                f.close()
                numlist.remove(r)
        finally:
            for i in range(numfiles):
                try:
                    sftp.remove('%s/file%d.txt' % (FOLDER, i))
                except:
                    pass

    def test_E_big_file(self):
        """
        write a 1MB file with no buffering.
        """
        global g_big_file_test
        if not g_big_file_test:
            return
        kblob = (1024 * 'x')
        start = time.time()
        try:
            f = sftp.open('%s/hongry.txt' % FOLDER, 'w')
            for n in range(1024):
                f.write(kblob)
                if n % 128 == 0:
                    sys.stderr.write('.')
            f.close()
            sys.stderr.write(' ')

            self.assertEqual(sftp.stat('%s/hongry.txt' % FOLDER).st_size, 1024 * 1024)
            end = time.time()
            sys.stderr.write('%ds ' % round(end - start))
            
            start = time.time()
            f = sftp.open('%s/hongry.txt' % FOLDER, 'r')
            for n in range(1024):
                data = f.read(1024)
                self.assertEqual(data, kblob)
            f.close()

            end = time.time()
            sys.stderr.write('%ds ' % round(end - start))
        finally:
            sftp.remove('%s/hongry.txt' % FOLDER)

    def test_F_big_file_pipelined(self):
        """
        write a 1MB file, with no linefeeds, using pipelining.
        """
        global g_big_file_test
        if not g_big_file_test:
            return
        kblob = (1024 * 'x')
        start = time.time()
        try:
            f = sftp.open('%s/hongry.txt' % FOLDER, 'w')
            f.set_pipelined(True)
            for n in range(1024):
                f.write(kblob)
                if n % 128 == 0:
                    sys.stderr.write('.')
            f.close()
            sys.stderr.write(' ')

            self.assertEqual(sftp.stat('%s/hongry.txt' % FOLDER).st_size, 1024 * 1024)
            end = time.time()
            sys.stderr.write('%ds ' % round(end - start))
            
            start = time.time()
            f = sftp.open('%s/hongry.txt' % FOLDER, 'r')
            f.prefetch()
            for n in range(1024):
                data = f.read(1024)
                self.assertEqual(data, kblob)
            f.close()

            end = time.time()
            sys.stderr.write('%ds ' % round(end - start))
        finally:
            sftp.remove('%s/hongry.txt' % FOLDER)

    def test_G_lots_of_prefetching(self):
        """
        prefetch a 1MB file a bunch of times, discarding the file object
        without using it, to verify that paramiko doesn't get confused.
        """
        global g_big_file_test
        if not g_big_file_test:
            return
        kblob = (1024 * 'x')
        try:
            f = sftp.open('%s/hongry.txt' % FOLDER, 'w')
            f.set_pipelined(True)
            for n in range(1024):
                f.write(kblob)
                if n % 128 == 0:
                    sys.stderr.write('.')
            f.close()
            sys.stderr.write(' ')

            self.assertEqual(sftp.stat('%s/hongry.txt' % FOLDER).st_size, 1024 * 1024)

            for i in range(10):
                f = sftp.open('%s/hongry.txt' % FOLDER, 'r')
                f.prefetch()
            f = sftp.open('%s/hongry.txt' % FOLDER, 'r')
            f.prefetch()
            for n in range(1024):
                data = f.read(1024)
                self.assertEqual(data, kblob)
                if n % 128 == 0:
                    sys.stderr.write('.')
            f.close()
            sys.stderr.write(' ')
        finally:
            sftp.remove('%s/hongry.txt' % FOLDER)
        
    def test_H_big_file_big_buffer(self):
        """
        write a 1MB file, with no linefeeds, and a big buffer.
        """
        global g_big_file_test
        if not g_big_file_test:
            return
        mblob = (1024 * 1024 * 'x')
        try:
            f = sftp.open('%s/hongry.txt' % FOLDER, 'w', 128 * 1024)
            f.write(mblob)
            f.close()

            self.assertEqual(sftp.stat('%s/hongry.txt' % FOLDER).st_size, 1024 * 1024)
        finally:
            sftp.remove('%s/hongry.txt' % FOLDER)
    
    def test_I_big_file_renegotiate(self):
        """
        write a 1MB file, forcing key renegotiation in the middle.
        """
        global g_big_file_test
        if not g_big_file_test:
            return
        t = sftp.sock.get_transport()
        t.packetizer.REKEY_BYTES = 512 * 1024
        k32blob = (32 * 1024 * 'x')
        try:
            f = sftp.open('%s/hongry.txt' % FOLDER, 'w', 128 * 1024)
            for i in xrange(32):
                f.write(k32blob)
            f.close()
            
            self.assertEqual(sftp.stat('%s/hongry.txt' % FOLDER).st_size, 1024 * 1024)
            self.assertNotEquals(t.H, t.session_id)
        finally:
            sftp.remove('%s/hongry.txt' % FOLDER)
            t.packetizer.REKEY_BYTES = pow(2, 30)

    def test_J_realpath(self):
        """
        test that realpath is returning something non-empty and not an
        error.
        """
        pwd = sftp.normalize('.')
        self.assert_(len(pwd) > 0)
        f = sftp.normalize('./' + FOLDER)
        self.assert_(len(f) > 0)
        self.assertEquals(os.path.join(pwd, FOLDER), f)

    def test_K_mkdir(self):
        """
        verify that mkdir/rmdir work.
        """
        try:
            sftp.mkdir(FOLDER + '/subfolder')
        except:
            self.assert_(False, 'exception creating subfolder')
        try:
            sftp.mkdir(FOLDER + '/subfolder')
            self.assert_(False, 'no exception overwriting subfolder')
        except IOError:
            pass
        try:
            sftp.rmdir(FOLDER + '/subfolder')
        except:
            self.assert_(False, 'exception removing subfolder')
        try:
            sftp.rmdir(FOLDER + '/subfolder')
            self.assert_(False, 'no exception removing nonexistent subfolder')
        except IOError:
            pass
    
    def test_L_chdir(self):
        """
        verify that chdir/getcwd work.
        """
        root = sftp.normalize('.')
        if root[-1] != '/':
            root += '/'
        try:
            sftp.mkdir(FOLDER + '/alpha')
            sftp.chdir(FOLDER + '/alpha')
            sftp.mkdir('beta')
            self.assertEquals(root + FOLDER + '/alpha', sftp.getcwd())
            self.assertEquals(['beta'], sftp.listdir('.'))
        
            sftp.chdir('beta')
            f = sftp.open('fish', 'w')
            f.write('hello\n')
            f.close()
            sftp.chdir('..')
            self.assertEquals(['fish'], sftp.listdir('beta'))
            sftp.chdir('..')
            self.assertEquals(['fish'], sftp.listdir('alpha/beta'))
        finally:
            sftp.chdir(root)
            try:
                sftp.unlink(FOLDER + '/alpha/beta/fish')
            except:
                pass
            try:
                sftp.rmdir(FOLDER + '/alpha/beta')
            except:
                pass
            try:
                sftp.rmdir(FOLDER + '/alpha')
            except:
                pass

    def test_M_get_put(self):
        """
        verify that get/put work.
        """
        import os, warnings
        warnings.filterwarnings('ignore', 'tempnam.*')
        
        localname = os.tempnam()
        text = 'All I wanted was a plastic bunny rabbit.\n'
        f = open(localname, 'w')
        f.write(text)
        f.close()
        sftp.put(localname, FOLDER + '/bunny.txt')
        
        f = sftp.open(FOLDER + '/bunny.txt', 'r')
        self.assertEquals(text, f.read(128))
        f.close()
        
        os.unlink(localname)
        localname = os.tempnam()
        sftp.get(FOLDER + '/bunny.txt', localname)
        
        f = open(localname, 'r')
        self.assertEquals(text, f.read(128))
        f.close()
    
        os.unlink(localname)
        sftp.unlink(FOLDER + '/bunny.txt')

    def test_N_check(self):
        """
        verify that file.check() works against our own server.
        (it's an sftp extension that we support, and may be the only ones who
        support it.)
        """
        f = sftp.open(FOLDER + '/kitty.txt', 'w')
        f.write('here kitty kitty' * 64)
        f.close()
        
        try:
            f = sftp.open(FOLDER + '/kitty.txt', 'r')
            sum = f.check('sha1')
            self.assertEquals('91059CFC6615941378D413CB5ADAF4C5EB293402', paramiko.util.hexify(sum))
            sum = f.check('md5', 0, 512)
            self.assertEquals('93DE4788FCA28D471516963A1FE3856A', paramiko.util.hexify(sum))
            sum = f.check('md5', 0, 0, 510)
            self.assertEquals('EB3B45B8CD55A0707D99B177544A319F373183D241432BB2157AB9E46358C4AC90370B5CADE5D90336FC1716F90B36D6',
                              paramiko.util.hexify(sum))
        finally:
            sftp.unlink(FOLDER + '/kitty.txt')

    def test_O_x_flag(self):
        """
        verify that the 'x' flag works when opening a file.
        """
        f = sftp.open(FOLDER + '/unusual.txt', 'wx')
        f.close()
        
        try:
            try:
                f = sftp.open(FOLDER + '/unusual.txt', 'wx')
                self.fail('expected exception')
            except IOError, x:
                pass
        finally:
            sftp.unlink(FOLDER + '/unusual.txt')
    
    def test_P_utf8(self):
        """
        verify that unicode strings are encoded into utf8 correctly.
        """
        f = sftp.open(FOLDER + '/something', 'w')
        f.write('okay')
        f.close()
        
        try:
            sftp.rename(FOLDER + '/something', FOLDER + u'/\u00fcnic\u00f8de')
            sftp.open(FOLDER + '/\xc3\xbcnic\xc3\xb8\x64\x65', 'r')
        except Exception, e:
            self.fail('exception ' + e)
        sftp.unlink(FOLDER + '/\xc3\xbcnic\xc3\xb8\x64\x65')