STEGBREAK(1) BSD General Commands Manual STEGBREAK(1)NAMEstegbreak — launches brute-force dictionary attacks on JPG image
SYNOPSIS
stegdetect [-qV] [-r rules] [-f wordlist] [-t tests] [-c] [file ...]
DESCRIPTION
The stegbreak states a brute-force dictionary attack against the speci‐
fied JPG images.
The options are as follows:
-q Only reports images for which the dictionary attack suc‐
ceeded.
-V Displays the version number of the software.
-r rules Contains rules with transformations that will be applied to
the words in the wordlist. The rules follow the same syntax
as in Solar Designers password cracking program John the
Ripper. The default is rules.ini.
-f wordlist Specifies the file that contains the words for the dictio‐
nary attack. The default is /usr/share/dict/words.
-t tests Sets the tests that are being run on the image. The follow‐
ing characters are understood:
o The dictionary attack follows the embedding
used by outguess.
p The dictionary attack follows the embedding
used by jphide.
j The dictionary attack follows the embedding
used by jsteg-shell.
The default value is p.
-c Specifies that the JPG images should be converted to a small
sized object that contains all the information necessary for
the dictionary attack. This can be used to reduce the size
of the data set in distributed computing applications.
The stegbreak prints the filename, the embedding system and the password
when the attack succeeded for an image. For jsteg-shell and outguess, it
also prints analysis results from the built in file utility.
Pressing Ctrl-C causes a status line to be displayed, pressing Ctrl-C a
second time within one second aborts the program.
EXAMPLESstegbreak-t p auto.jpg
Launches a brute-force dictionary attack against auto.jpg assuming that
information has been embedded with jphide.
FILES
/usr/share/dict/words default wordfile for the dictionary
attack.
/usr/local/share/stegbreak/rules.ini rules on how to manipulate words
for the dictionary attack, from
John the Ripper.
SEE ALSOstegdetect(1)ACKNOWLEDGEMENTS
This program contains source code from Solar Designer's John the Ripper.
It has been placed under a BSD-license with his permission.
This product includes software developed by Ian F. Darwin and others.
The stegbreak utility uses Darwin's file magic to verify results from
OutGuess key guessing.
Korejwa provided information on the data format used by JSteg Shell.
AUTHORS
The stegbreak utility has been developed by Niels Provos.
BSD July 05, 2001 BSD
