This repository has been archived by the owner on Jun 7, 2018. It is now read-only.
-
Notifications
You must be signed in to change notification settings - Fork 62
/
afl_collect.py
executable file
·518 lines (406 loc) · 21 KB
/
afl_collect.py
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
"""
Copyright 2015-2016 @_rc0r <hlt99@blinkenshell.org>
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
"""
import argparse
import exploitable
import os
import queue
import shutil
import sys
import threading
import afl_utils
from afl_utils import SampleIndex, AflThread
from afl_utils.AflPrettyPrint import clr, print_ok, print_err, print_warn
from db_connectors import con_sqlite
# afl-collect global settings
global_crash_subdirs = "crashes"
global_queue_subdirs = "queue"
global_exclude_files = [
"README.txt",
]
fuzzer_stats_filename = "fuzzer_stats"
# gdb settings
# Path to gdb binary
gdb_binary = shutil.which("gdb")
# afl-collect database table spec
db_table_spec = """`Sample` TEXT PRIMARY KEY NOT NULL, `Classification` TEXT NOT NULL,
`Classification_Description` TEXT NOT NULL, `Hash` TEXT, `User_Comment` TEXT"""
def check_gdb():
if gdb_binary is None:
print_err("gdb binary not found!")
sys.exit(1)
def show_info():
print(clr.CYA + "afl-collect " + clr.BRI + "%s" % afl_utils.__version__ + clr.RST + " by %s" % afl_utils.__author__)
print("Crash sample collection and processing utility for afl-fuzz.")
print("")
def get_fuzzer_instances(sync_dir, crash_dirs=True):
if not os.path.isabs(sync_dir):
sync_dir = os.path.abspath(sync_dir)
fuzzer_inst = []
fuzzer_stats_file = os.path.join(sync_dir, fuzzer_stats_filename)
if os.path.exists(fuzzer_stats_file) and os.path.isfile(fuzzer_stats_file):
# we're inside a single instance output dir
fuzzer_inst.append((sync_dir, []))
else:
# we're inside a multi instance sync dir
for fdir in os.listdir(sync_dir):
if os.path.isdir(os.path.join(sync_dir, fdir)):
fuzzer_inst.append((fdir, []))
if crash_dirs:
fuzzer_inst = get_crash_directories(sync_dir, fuzzer_inst)
else:
fuzzer_inst = get_queue_directories(sync_dir, fuzzer_inst)
return fuzzer_inst
def get_crash_directories(sync_dir, fuzzer_instances):
for fi in fuzzer_instances:
fuzz_dir = os.path.join(sync_dir, fi[0])
for cdir in os.listdir(fuzz_dir):
if os.path.isdir(os.path.join(fuzz_dir, cdir)) and global_crash_subdirs in cdir:
fi[1].append(cdir)
return fuzzer_instances
def get_queue_directories(sync_dir, fuzzer_instances):
for fi in fuzzer_instances:
fuzz_dir = os.path.join(sync_dir, fi[0])
for qdir in os.listdir(fuzz_dir):
if os.path.isdir(os.path.join(fuzz_dir, qdir)) and global_queue_subdirs in qdir:
fi[1].append(qdir)
return fuzzer_instances
def get_samples_from_dir(sample_subdir, abs_path=False):
samples = []
num_samples = 0
for f in os.listdir(sample_subdir):
if os.path.isfile(os.path.join(sample_subdir, f)) and f not in global_exclude_files:
if abs_path:
samples.append(os.path.join(sample_subdir, f))
else:
samples.append(f)
num_samples += 1
return num_samples, samples
def collect_samples(sync_dir, fuzzer_instances):
samples = []
num_samples = 0
for fi in fuzzer_instances:
fuzz_dir = os.path.join(sync_dir, fi[0])
fuzz_samples = []
for cd in fi[1]:
tmp_num_samples, tmp_samples = get_samples_from_dir(os.path.join(fuzz_dir, cd))
fuzz_samples.append((cd, sorted(tmp_samples)))
num_samples += tmp_num_samples
samples.append((fi[0], fuzz_samples))
return num_samples, samples
def build_sample_index(sync_dir, out_dir, fuzzer_instances, db=None, min_filename=False, omit_fuzzer_name=False):
sample_num, samples = collect_samples(sync_dir, fuzzer_instances)
sample_index = SampleIndex.SampleIndex(out_dir, min_filename=min_filename, omit_fuzzer_name=omit_fuzzer_name)
for fuzzer in samples:
for sample_dir in fuzzer[1]:
for sample in sample_dir[1]:
sample_file = os.path.join(sync_dir, "%s/%s/%s" % (fuzzer[0], sample_dir[0], sample))
sample_name = sample_index.__generate_output__(fuzzer[0], sample_file)
if not db or not db.dataset_exists('Data', {'Sample': sample_name, 'Classification': '%',
'Classification_Description': '%',
'Hash': '%', 'User_Comment': '%'}, ['Sample']):
sample_index.add(fuzzer[0], sample_file)
return sample_index
def copy_samples(sample_index):
files_collected = []
for sample in sample_index.index:
dst_file = shutil.copyfile(sample['input'], os.path.join(sample_index.output_dir, sample['output']))
files_collected.append(dst_file)
return files_collected
def generate_sample_list(list_filename, files_collected):
list_filename = os.path.abspath(os.path.expanduser(list_filename))
try:
fd = open(list_filename, "w")
for f in files_collected:
fd.writelines("%s\n" % f)
fd.close()
except (FileExistsError, PermissionError):
print_err("Could not create file list '%s'!" % list_filename)
def stdin_mode(target_cmd):
return not ("@@" in target_cmd)
def generate_gdb_exploitable_script(script_filename, sample_index, target_cmd, script_id=0, intermediate=False):
target_cmd = target_cmd.split()
gdb_target_binary = target_cmd[0]
gdb_run_cmd = " ".join(target_cmd[1:])
if not intermediate:
script_filename = os.path.abspath(os.path.expanduser(script_filename))
print_ok("Generating final gdb+exploitable script '%s' for %d samples..." % (script_filename,
len(sample_index.outputs())))
else:
script_filename = os.path.abspath(os.path.expanduser("%s.%d" % (script_filename, script_id)))
print_ok("Generating intermediate gdb+exploitable script '%s' for %d samples..." %
(script_filename, len(sample_index.outputs())))
gdb_exploitable_path = None
gdbinit = os.path.expanduser("~/.gdbinit")
if not os.path.exists(gdbinit) or b"exploitable.py" not in open(gdbinit, "rb").read():
gdb_exploitable_path = os.path.join(exploitable.__path__[0], "exploitable.py")
try:
fd = open(script_filename, "w")
# <script header>
# source exploitable.py if necessary
if gdb_exploitable_path:
fd.writelines("source %s\n" % gdb_exploitable_path)
# load executable
fd.writelines("file %s\n" % gdb_target_binary)
# </script_header>
# fill script with content
for f in sample_index.index:
fd.writelines("echo Crash\ sample:\ '%s'\\n\n" % f['output'])
if not stdin_mode(target_cmd):
run_cmd = "run " + gdb_run_cmd + "\n"
else:
run_cmd = "run " + gdb_run_cmd + "< @@" + "\n"
if intermediate:
run_cmd = run_cmd.replace("@@", "'{}'".format(f['input']))
else:
run_cmd = run_cmd.replace("@@", os.path.join(sample_index.output_dir, "'{}'".format(f['output'])))
fd.writelines(run_cmd)
fd.writelines("exploitable\n")
# <script_footer>
fd.writelines("quit")
# </script_footer>
fd.close()
except (FileExistsError, PermissionError):
print_err("Could not open script file '%s' for writing!" % script_filename)
# ok, this needs improvement!!!
def execute_gdb_script(out_dir, script_filename, num_samples, num_threads):
classification_data = []
out_dir = os.path.expanduser(out_dir) + "/"
grep_for = [
"Crash sample: '",
"Exploitability Classification: ",
"Short description: ",
"Hash: ",
]
queue_list = []
thread_list = []
for n in range(0, num_threads, 1):
script_args = [
str(gdb_binary),
"-x",
str(os.path.join(out_dir, "%s.%d" % (script_filename, n))),
]
out_queue = queue.Queue()
out_queue_lock = threading.Lock()
queue_list.append((out_queue, out_queue_lock))
t = AflThread.GdbThread(n, script_args, out_dir, grep_for, out_queue, out_queue_lock)
thread_list.append(t)
print_ok("Executing gdb+exploitable script '%s.%d'..." % (script_filename, n))
t.daemon = True
t.start()
for t in thread_list:
t.join()
grepped_output = []
for q in queue_list:
q[1].acquire()
while not q[0].empty():
grepped_output.append(q[0].get())
q[1].release()
i = 1
print("*** GDB+EXPLOITABLE SCRIPT OUTPUT ***")
for g in range(0, len(grepped_output)-len(grep_for)+1, len(grep_for)):
if grepped_output[g+3] == "EXPLOITABLE":
cex = clr.RED
ccl = clr.BRI
elif grepped_output[g+3] == "PROBABLY_EXPLOITABLE":
cex = clr.YEL
ccl = clr.BRI
elif grepped_output[g+3] == "PROBABLY_NOT_EXPLOITABLE":
cex = clr.BRN
ccl = clr.RST
elif grepped_output[g+3] == "NOT_EXPLOITABLE":
cex = clr.GRN
ccl = clr.GRA
elif grepped_output[g+3] == "UNKNOWN":
cex = clr.BLU
ccl = clr.GRA
else:
cex = clr.GRA
ccl = clr.GRA
if len(grepped_output[g]) < 24:
# Assume simplified sample file names,
# so save some output space.
ljust_width = 24
else:
ljust_width = 64
print("%s[%05d]%s %s: %s%s%s %s[%s]%s" % (clr.GRA, i, clr.RST, grepped_output[g].ljust(ljust_width, '.'), cex,
grepped_output[g+3], clr.RST, ccl, grepped_output[g+1], clr.RST))
classification_data.append({'Sample': grepped_output[g], 'Classification': grepped_output[g+3],
'Classification_Description': grepped_output[g+1], 'Hash': grepped_output[g+2],
'User_Comment': ''})
i += 1
if i > 1 and i < num_samples:
print("%s[%05d]%s %s: %sINVALID SAMPLE (Aborting!)%s" % (clr.GRA, i, clr.RST,
grepped_output[-1].ljust(ljust_width, '.'),
clr.LRD, clr.RST))
print(clr.LRD + "Returned data may be incomplete!" + clr.RST)
print("*** ***************************** ***")
# remove intermediate gdb scripts...
for n in range(0, num_threads, 1):
os.remove(os.path.join(out_dir, "%s.%d" % (script_filename, n)))
return classification_data
def main(argv):
show_info()
check_gdb()
parser = argparse.ArgumentParser(description="afl-collect copies all crash sample files from an afl sync dir used \
by multiple fuzzers when fuzzing in parallel into a single location providing easy access for further crash analysis.",
usage="afl-collect [-d DATABASE] [-e|-g GDB_EXPL_SCRIPT_FILE] [-f LIST_FILENAME]\n \
[-h] [-j THREADS] [-m] [-r [-rt TIMEOUT]] [-rr] sync_dir collection_dir -- target_cmd")
parser.add_argument("sync_dir", help="afl synchronisation directory crash samples will be collected from.")
parser.add_argument("collection_dir",
help="Output directory that will hold a copy of all crash samples and other generated files. \
Existing files in the collection directory will be overwritten!")
parser.add_argument("-d", "--database", dest="database_file", help="Submit sample data into an sqlite3 database (\
only when used together with '-e'). afl-collect skips processing of samples already found in existing database.",
default=None)
parser.add_argument("-e", "--execute-gdb-script", dest="gdb_expl_script_file",
help="Generate and execute a gdb+exploitable script after crash sample collection for crash \
classification. (Like option '-g', plus script execution.)",
default=None)
parser.add_argument("-f", "--filelist", dest="list_filename", default=None,
help="Writes all collected crash sample filenames into a file in the collection directory.")
parser.add_argument("-g", "--generate-gdb-script", dest="gdb_script_file",
help="Generate gdb script to run 'exploitable.py' on all collected crash samples. Generated \
script will be placed into collection directory.", default=None)
parser.add_argument("-j", "--threads", dest="num_threads", default=1,
help="Enable parallel analysis by specifying the number of threads afl-collect will utilize.")
parser.add_argument("-m", "--minimize-filenames", dest="min_filename", action="store_const", const=True,
default=False, help="Minimize crash sample file names by only keeping fuzzer name and ID.")
parser.add_argument("-r", "--remove-invalid", dest="remove_invalid", action="store_const", const=True,
default=False, help="Verify collected crash samples and remove samples that do not lead to \
crashes or cause timeouts (runs 'afl-vcrash.py -r' on collection directory). This step is done prior to any script \
file execution or file list generation.")
parser.add_argument("-rr", "--remove-unexploitable", dest="remove_unexploitable", action="store_const", const=True,
default=False, help="Remove crash samples that have an exploitable classification of \
'NOT_EXPLOITABLE' or 'PROBABLY_NOT_EXPLOITABLE'. Sample file removal will take place after gdb+exploitable \
script execution. Has no effect without '-e'.")
parser.add_argument("-rt", "--remove-timeout", dest="remove_timeout", default=10,
help="Specifies the maximum processing time in seconds for each sample during verification \
phase. Samples that cause the target to run longer are marked as timeouts and are removed from the index. Has no \
effect without '-r'.")
parser.add_argument("target_cmd", nargs="+", help="Path to the target binary and its command line arguments. \
Use '@@' to specify crash sample input file position (see afl-fuzz usage).")
args = parser.parse_args(argv[1:])
sync_dir = os.path.abspath(os.path.expanduser(args.sync_dir))
if not os.path.exists(sync_dir):
print_err("No valid directory provided for <SYNC_DIR>!")
return
out_dir = os.path.abspath(os.path.expanduser(args.collection_dir))
if not os.path.exists(out_dir):
os.makedirs(out_dir, exist_ok=True)
args.target_cmd = " ".join(args.target_cmd).split()
args.target_cmd[0] = os.path.abspath(os.path.expanduser(args.target_cmd[0]))
if not os.path.exists(args.target_cmd[0]):
print_err("Target binary not found!")
return
args.target_cmd = " ".join(args.target_cmd)
if args.database_file:
db_file = os.path.abspath(os.path.expanduser(args.database_file))
else:
db_file = None
print_ok("Going to collect crash samples from '%s'." % sync_dir)
# initialize database
if db_file:
lite_db = con_sqlite.sqliteConnector(db_file)
lite_db.init_database('Data', db_table_spec)
else:
lite_db = None
fuzzers = get_fuzzer_instances(sync_dir)
print_ok("Found %d fuzzers, collecting crash samples." % len(fuzzers))
sample_index = build_sample_index(sync_dir, out_dir, fuzzers, lite_db, args.min_filename)
if len(sample_index.index) > 0:
print_ok("Successfully indexed %d crash samples." % len(sample_index.index))
elif db_file:
print_warn("No unseen samples found. Check your database for results!")
return
else:
print_warn("No samples found. Check directory settings!")
return
if args.remove_invalid:
from afl_utils import afl_vcrash
invalid_samples, timeout_samples = afl_vcrash.verify_samples(int(args.num_threads), sample_index.inputs(),
args.target_cmd, timeout_secs=float(args.remove_timeout))
# store invalid samples in db
if args.gdb_expl_script_file and db_file:
print_ok("Saving invalid sample info to database.")
for sample in invalid_samples:
sample_name = sample_index.outputs(input_file=sample)
dataset = {'Sample': sample_name[0], 'Classification': 'INVALID',
'Classification_Description': 'Sample does not cause a crash in the target.', 'Hash': '',
'User_Comment': ''}
if not lite_db.dataset_exists('Data', dataset, ['Sample']):
lite_db.insert_dataset('Data', dataset)
for sample in timeout_samples:
sample_name = sample_index.outputs(input_file=sample)
dataset = {'Sample': sample_name[0], 'Classification': 'TIMEOUT',
'Classification_Description': 'Sample caused a target execution timeout.', 'Hash': '',
'User_Comment': ''}
if not lite_db.dataset_exists('Data', dataset, ['Sample']):
lite_db.insert_dataset('Data', dataset)
# remove invalid samples from sample index
sample_index.remove_inputs(invalid_samples+timeout_samples)
print_warn("Removed %d invalid crash samples from index." % len(invalid_samples))
print_warn("Removed %d timed out samples from index." % len(timeout_samples))
# generate gdb+exploitable script
if args.gdb_expl_script_file:
divided_index = sample_index.divide(int(args.num_threads))
for i in range(0, int(args.num_threads), 1):
generate_gdb_exploitable_script(os.path.join(out_dir, args.gdb_expl_script_file), divided_index[i],
args.target_cmd, i, intermediate=True)
# execute gdb+exploitable script
classification_data = execute_gdb_script(out_dir, args.gdb_expl_script_file, len(sample_index.inputs()),
int(args.num_threads))
# Submit crash classification data into database
if db_file:
print_ok("Saving sample classification info to database.")
for dataset in classification_data:
if not lite_db.dataset_exists('Data', dataset, ['Sample']):
lite_db.insert_dataset('Data', dataset)
# de-dupe by exploitable hash
seen = set()
seen_add = seen.add
classification_data_dedupe = [x for x in classification_data
if x['Hash'] not in seen and not seen_add(x['Hash'])]
# remove dupe samples identified by exploitable hash
uninteresting_samples = [x['Sample'] for x in classification_data
if x not in classification_data_dedupe]
sample_index.remove_outputs(uninteresting_samples)
print_warn("Removed %d duplicate samples from index. Will continue with %d remaining samples." %
(len(uninteresting_samples), len(sample_index.index)))
# remove crash samples that are classified uninteresting
if args.remove_unexploitable:
classification_unexploitable = [
'NOT_EXPLOITABLE',
'PROBABLY_NOT_EXPLOITABLE',
]
uninteresting_samples = []
for c in classification_data_dedupe:
if c['Classification'] in classification_unexploitable:
uninteresting_samples.append(c['Sample'])
sample_index.remove_outputs(uninteresting_samples)
print_warn("Removed %d uninteresting crash samples from index." % len(uninteresting_samples))
# generate output gdb script
generate_gdb_exploitable_script(os.path.join(out_dir, args.gdb_expl_script_file), sample_index,
args.target_cmd, 0)
elif args.gdb_script_file:
generate_gdb_exploitable_script(os.path.join(out_dir, args.gdb_script_file), sample_index, args.target_cmd)
print_ok("Copying %d samples into output directory..." % len(sample_index.index))
files_collected = copy_samples(sample_index)
# generate filelist of collected crash samples
if args.list_filename:
generate_sample_list(os.path.abspath(os.path.expanduser(args.list_filename)), files_collected)
print_ok("Generated crash sample list '%s'." % os.path.abspath(os.path.expanduser(args.list_filename)))
# write db contents to file and close db connection
if db_file:
lite_db.commit_close()
if __name__ == "__main__":
main(sys.argv)