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Date: Sun, 28 Jun 2015 17:06:46 +0200
From: Frank Dittrich <frank.dittrich@...lbox.org>
To: john-dev@...ts.openwall.com
Subject: Re: more robustness
On 06/28/2015 01:54 PM, Kai Zhao wrote:
>> I think more people might try out and comment on your new --fuzz option
>> if you would push your changes to (a separate branch of) your own github
>> repository and provide a link to that repository/branch.
>
> Thanks, here is the link:
>
> https://github.com/loverszhaokai/JohnTheRipper/tree/fuzz_option
1.
I think you should mention the --fuzz[=DICTFILE] option in the
--list=hidden-options output, if only to make the option known to john's
bash completion.
I would add it after the --stress-test[=TIME] option.
2.
I did:
(fuzz_option)src $ ./configure --disable-openmp --enable-asan
(fuzz_option)src $ make -s -j 16
(fuzz_option)src $ cd ../run
(fuzz_option)run $ ./john --fuzz --format=MSCHAPv2
Fuzzing: MSCHAPv2, C/R [MD4 DES (ESS MD5) 128/128 AVX 4x3] in UTF-8 mode...
=================================================================
==19657==ERROR: AddressSanitizer: global-buffer-overflow on address
0x0000008099ff at pc 0x0000006b88c6 bp 0x7ffd10c110d0 sp 0x7ffd10c110c0
READ of size 1 at 0x0000008099ff thread T0
#0 0x6b88c5 in append_last_char /home/fd/git/fuzz-JtR/src/formats.c:858
#1 0x6b92a5 in get_next_fuzz_case
/home/fd/git/fuzz-JtR/src/formats.c:1114
#2 0x6bd2fd in fuzz_test /home/fd/git/fuzz-JtR/src/formats.c:1147
#3 0x6a4d2e in fuzz /home/fd/git/fuzz-JtR/src/bench.c:829
#4 0x6c995d in john_run /home/fd/git/fuzz-JtR/src/john.c:1367
#5 0x6cae5c in main /home/fd/git/fuzz-JtR/src/john.c:1753
#6 0x7f714bdeb78f in __libc_start_main (/lib64/libc.so.6+0x2078f)
#7 0x406878 in _start (/home/fd/git/fuzz-JtR/run/john+0x406878)
0x0000008099ff is located 1 bytes to the left of global variable
'*.LC22' defined in 'ntlmv1_mschapv2_fmt_plug.c' (0x809a00) of size 1
'*.LC22' is ascii string ''
0x0000008099ff is located 61 bytes to the right of global variable
'*.LC21' defined in 'ntlmv1_mschapv2_fmt_plug.c' (0x8099a0) of size 34
'*.LC21' is ascii string 'MD4 DES (ESS MD5) 128/128 AVX 4x3'
SUMMARY: AddressSanitizer: global-buffer-overflow
/home/fd/git/fuzz-JtR/src/formats.c:858 append_last_char
Shadow bytes around the buggy address:
0x0000800f92e0: 00 00 00 00 00 03 f9 f9 f9 f9 f9 f9 00 02 f9 f9
0x0000800f92f0: f9 f9 f9 f9 00 00 01 f9 f9 f9 f9 f9 00 00 01 f9
0x0000800f9300: f9 f9 f9 f9 00 00 00 00 00 00 01 f9 f9 f9 f9 f9
0x0000800f9310: 00 00 00 00 01 f9 f9 f9 f9 f9 f9 f9 00 00 01 f9
0x0000800f9320: f9 f9 f9 f9 00 f9 f9 f9 f9 f9 f9 f9 00 03 f9 f9
=>0x0000800f9330: f9 f9 f9 f9 00 00 00 00 02 f9 f9 f9 f9 f9 f9[f9]
0x0000800f9340: 01 f9 f9 f9 f9 f9 f9 f9 00 01 f9 f9 f9 f9 f9 f9
0x0000800f9350: 04 f9 f9 f9 f9 f9 f9 f9 00 00 00 00 00 00 00 00
0x0000800f9360: 00 03 f9 f9 f9 f9 f9 f9 00 00 f9 f9 f9 f9 f9 f9
0x0000800f9370: 00 00 00 00 00 00 00 00 00 00 00 03 f9 f9 f9 f9
0x0000800f9380: 00 01 f9 f9 f9 f9 f9 f9 00 00 00 00 00 00 00 00
Shadow byte legend (one shadow byte represents 8 application bytes):
Addressable: 00
Partially addressable: 01 02 03 04 05 06 07
Heap left redzone: fa
Heap right redzone: fb
Freed heap region: fd
Stack left redzone: f1
Stack mid redzone: f2
Stack right redzone: f3
Stack partial redzone: f4
Stack after return: f5
Stack use after scope: f8
Global redzone: f9
Global init order: f6
Poisoned by user: f7
Container overflow: fc
Array cookie: ac
Intra object redzone: bb
ASan internal: fe
==19657==ABORTING
This looks like a buffer overflow in your fuzzer, doesn't it?
(It took almost half an hour until I got this ASan error.)
3.
(fuzz_option)run $ ./john --list=build-info
Version: 1.8.0.6-jumbo-1-bleeding_asan
Build: linux-gnu 64-bit AVX-autoconf
Time stamp: Sun Jun 28 14:02:04 2015
You could rebase your git repository on magnum's latest bleeding-jumbo.
It might have some bugs fixed, and it reports much more useful version
info than that "time stamp" (actually, the time listconf.c changed):
(bleeding-jumbo)run $ ./john --list=build-info
Version: 1.8.0.6-jumbo-1-154-g96aeffc
Build: linux-gnu 64-bit AVX-autoconf OMP
That version string tells you that my git repository is 154 commits
ahead of 1.8.0.6-jumbo, my latest commit is 96aeffc.
This is a local commit, as
$ git show 96aeffc
will tell you.
And, I have no uncommitted changes in my git repository, otherwise the
version string would be 1.8.0.6-jumbo-1-154-g96aeffc+ instead.
While a git push --force (and thus, changing history) isn't a good idea
for public repositories that are supposed to be pulled by others (e.g.,
magnum's JohnTheRipper repository or Shinnok's johnny repository, I
think it wouldn't be much of a problem for your repository, so I think
it is up to you whether you merge or rebase.
Frank
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