.\"	$OpenBSD: mdoc.template,v 1.6 2001/02/03 08:22:44 niklas Exp $
.\"
.\" The following requests are required for all man pages.
.Dd July 05, 2001
.Dt STEGBREAK 1
.Os
.Sh NAME
.Nm stegbreak
.Nd launches brute-force dictionary attacks on JPG image
.Sh SYNOPSIS
.\" For a program:  program [-abc] file ...
.Nm stegdetect
.Op Fl qV
.Op Fl r Ar rules
.Op Fl f Ar wordlist
.Op Fl t Ar tests
.Op Fl c
.Op Ar file ...
.Sh DESCRIPTION
The
.Nm
states a brute-force dictionary attack against the specified JPG
images.
.Pp
The options are as follows:
.Bl -tag -width Df_wordlist
.It Fl q
Only reports images for which the dictionary attack succeeded.
.It Fl V
Displays the version number of the software.
.It Fl r Ar 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
.Pa rules.ini .
.It Fl f Ar wordlist
Specifies the file that contains the words for the dictionary attack.
The default is
.Pa /usr/share/dict/words .
.It Fl t Ar tests
Sets the tests that are being run on the image.  The following characters
are understood:
.Bl -tag -width Do
.It o
The dictionary attack follows the embedding used by
.Tn outguess .
.It p
The dictionary attack follows the embedding used by
.Tn jphide .
.It j
The dictionary attack follows the embedding used by
.Tn jsteg-shell .
.El
.Pp
The default value is
.Va p .
.It Fl 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.
.El
.Pp
The
.Nm
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
.Pa file
utility.
.Pp
Pressing Ctrl-C causes a status line to be displayed, pressing
Ctrl-C a second time within one second aborts the program.
.Pp

.Sh EXAMPLES
.Cm stegbreak -t p auto.jpg
.Pp
Launches a brute-force dictionary attack against
.Fa auto.jpg
assuming that information has been embedded with
.Tn jphide .
.Sh FILES
.Bl -tag -width /usr/local/share/stegbreak/rules.ini -compact
.It Pa /usr/share/dict/words
default wordfile for the dictionary attack.
.It Pa /usr/local/share/stegbreak/rules.ini
rules on how to manipulate words for the dictionary attack, from
John the Ripper.
.El
.Sh SEE ALSO
.Xr stegdetect 1
.Sh ACKNOWLEDGEMENTS
This program contains source code from Solar Designer's John the
Ripper.  It has been placed under a BSD-license with his permission.
.Pp
This product includes software developed by Ian F. Darwin and others.
The
.Nm
utility uses Darwin's file magic to verify results from OutGuess key guessing.

.Pp
Korejwa provided information on the data format used by JSteg Shell.
.Sh AUTHORS
The
.Nm
utility has been developed by Niels Provos.
.\" .Sh HISTORY
.\" .Sh BUGS
.\" .Sh CAVEATS