John the Ripper's command line syntax.

When invoked with no command line arguments, "john" prints its usage
summary.

The supported command line arguments are password file names and
options.  Many of the supported options accept additional arguments.

You can list any number of password files right on the command line of
"john".  You do not have to specify any options.  If valid password
files are specified but no options are given, John will go through
the default selection of cracking modes with their default settings.

Options may be specified along with password files or on their own,
although some require that password files be specified and some do not
support operation on password files.

All options are case sensitive, can be abbreviated as long as the
abbreviations are unambiguous, can be prefixed with two dashes
(GNU-style) or with one dash, and can use "=" or ":" to indicate an
argument (if supported for a given option).

The supported options are as follows, square brackets denote optional
arguments:

--single			"single crack" mode

Enables the "single crack" mode, using rules from the configuration
file section [List.Rules:Single].

--wordlist=FILE			wordlist mode, read words from FILE,
--stdin				or from stdin

These are used to enable the wordlist mode.

--rules				enable word mangling rules for wordlist mode

Enables word mangling rules that are read from [List.Rules:Wordlist].

--incremental[=MODE]		"incremental" mode [using section MODE]

Enables the "incremental" mode, using the specified configuration file
definition (section [Incremental:MODE], or [Incremental:All] by default
except for LM hashes for which the default is [Incremental:LanMan]).

--external=MODE			external mode or word filter

Enables an external mode, using external functions defined in section
[List.External:MODE].

--stdout[=LENGTH]		just output candidate passwords

When used with a cracking mode, except for "single crack", makes John
output the candidate passwords it generates to stdout instead of
actually trying them against password hashes; no password files may be
specified when this option is used.  If a LENGTH is given, John
assumes that to be the significant password length and only produces
passwords up to that length.

--restore[=NAME]		restore an interrupted session

Continues an interrupted cracking session, reading state information
from the specified session file or from $JOHN/john.rec by default.

--session=NAME			give a new session the NAME

This option can only be used when starting a new cracking session and
its purpose is to give the new session a name (to which John will
append the ".rec" suffix to form the session file name).  This is
useful for running multiple instances of John in parallel or to be
able to later recover a session other than the last one you interrupt.

--status[=NAME]			print status of a session [called NAME]

Prints status of an interrupted or running session.  Note that on a
Unix-like system, you can get a detached running session to update its
session file by sending a SIGHUP to the appropriate "john" process;
then use this option to read in and display the status.

--make-charset=FILE		make a charset, overwriting FILE

Generates a charset file based on character frequencies from
$JOHN/john.pot, for use with the "incremental" mode.  The entire
$JOHN/john.pot will be used for the charset generation by default.  You
may restrict the set of passwords used by specifying some password files
(in which case only the cracked passwords that correspond to those
password files will be used), "--format", or/and "--external" (with an
external mode that defines a filter() function).

--show				show cracked passwords

Shows the cracked passwords for given password files (which you must
specify).  You can use this option while another instance of John is
cracking to see what John did so far; to get the most up to date
information, first send a SIGHUP to the appropriate "john" process.

--test[=TIME]			run tests and benchmarks for TIME seconds each

Tests all of the compiled in hashing algorithms for proper operation and
benchmarks them.  The "--format" option can be used to restrict this to
a specific algorithm.

--users=[-]LOGIN|UID[,..]	[do not] load this (these) user(s)

Allows you to select just a few accounts for cracking or for other
operations.  A dash before the list can be used to invert the check
(that is, load information for all the accounts that are not listed).

--groups=[-]GID[,..]		load users [not] of this (these) group(s)

Tells John to load (or to not load) information for accounts in the
specified group(s) only.

--shells=[-]SHELL[,..]		load users with[out] this (these) shell(s)

This option is useful to load accounts with a valid shell only or to
not load accounts with a bad shell.  You can omit the path before a
shell name, so "--shells=csh" will match both "/bin/csh" and
"/usr/bin/csh", while "--shells=/bin/csh" will only match "/bin/csh".

--salts=[-]COUNT		load salts with[out] at least COUNT passwords

This is a feature which allows to achieve better performance in some
special cases.  For example, you can crack only some salts using
"--salts=2" faster and then crack the rest using "--salts=-2".  Total
cracking time will be about the same, but you will likely get some
passwords cracked earlier.

--format=NAME			force hash type NAME

Allows you to override the hash type detection.  Currently, valid
"format names" are DES, BSDI, MD5, BF, AFS, LM, and crypt (and many more
are added with various patches).  You can use this option when you're
starting a cracking session or along with one of: "--test", "--show",
"--make-charset".  Note that John can't crack hashes of different types
at the same time.  If you happen to get a password file that uses more
than one hash type, then you have to invoke John once for each hash type
and you need to use this option to make John crack hashes of types other
than the one it would autodetect by default.

"--format=crypt" may or may not be supported in a given build of John.
In default builds of John, this support is currently only included on
Linux and Solaris.  When specified (and supported), this option makes
John use the system's crypt(3) or crypt_r(3) function.  This may be
needed to audit password hashes supported by the system, but not yet
supported by John's own optimized cryptographic routines.  Currently,
this is the case for glibc 2.7+ SHA-crypt hashes as used by recent
versions of Fedora and Ubuntu, and for SunMD5 hashes supported (but not
used by default) on recent versions of Solaris.  In fact, you do not
have to explicitly specify "--format=crypt" for hashes of these specific
types unless you have other hash types (those supported by John
natively) in the password file(s) as well (in which case another hash
type may get detected unless you specify this option).

"--format=crypt" is also a way to make John crack crypt(3) hashes of
different types at the same time, but doing so results in poor
performance and in unnecessarily poor results (in terms of passwords
cracked) for hashes of the "faster" types (as compared to the "slower"
ones loaded for cracking at the same time).  So you are advised to use
separate invocations of John, one per hash type.

--save-memory=LEVEL		enable memory saving, at LEVEL 1..3

You might need this option if you don't have enough memory or don't
want John to affect other processes too much.  Level 1 tells John to
not waste memory on login names; it is only supported when a cracking
mode other than "single crack" is explicitly requested.  The only
impact is that you won't see the login names while cracking.  Higher
memory saving levels have a performance impact; you should probably
avoid using them unless John doesn't work or gets into swap otherwise.


	Additional utilities (compiled/installed along with John).

There are some related utilities in John's run directory.  (Depending on
platform, these may be symlinks to the main John program binary.)

	unshadow PASSWORD-FILE SHADOW-FILE

Combines the "passwd" and "shadow" files (when you already have access
to both) for use with John.  You might need this since if you only
used your shadow file, the "Full Name" or "GECOS" information wouldn't
be used by the "single crack" mode (thus reducing its efficiency) and
you wouldn't be able to use the "--groups" and "--shells" options and
to select by UID with "--users".  You probably also want to see all of
the passwd file fields with "--show".

You'll usually want to redirect the output of "unshadow" to a file
which you then pass to John.

	unafs DATABASE-FILE CELL-NAME

Gets password hashes out of the binary AFS database and produces
output usable by John (you should redirect the output to a file).

	unique OUTPUT-FILE

Removes duplicates from a wordlist (read from stdin) without changing
the order of entries.  You might want to use this with John's
"--stdout" option if you've got a lot of disk space to trade for the
reduced cracking time (on possibly trying some duplicates as they
might be produced with word mangling rules).


	Scripts.

There are also some related scripts supplied in John's run directory.
(Binary packages of John may choose to install these along with the
documentation instead.)

	relbench BENCHMARK-FILE-1 BENCHMARK-FILE-2

relbench is a Perl script to compare two "john --test" benchmark runs,
such as for different machines, "make" targets, C compilers,
optimization options, or/and versions of John the Ripper.  To use it,
redirect the output of each "john --test" run to a file, then run the
script on the two files.  Most values output by the script indicate
relative performance seen on the second benchmark run as compared to the
first one, with the value of 1.0 indicating no change, values higher
than 1.0 indicating speedup, and values lower than 1.0 indicating
slowdown.  Specifically, the script outputs the minimum, maximum,
median, and geometric mean for the speedup (or slowdown) seen across the
many individual benchmarks that "john --test" performs.  It also outputs
the median absolute deviation (relative to the median) and geometric
standard deviation (relative to the geometric mean).  Of these two, a
median absolute deviation of 0.0 would indicate that no deviation from
the median is prevalent, whereas a geometric standard deviation of 1.0
would indicate that all benchmarks were sped up or slowed down by the
exact same ratio or their speed remained unchanged.  In practice, these
values will tend to deviate from 0.0 and 1.0, respectively.

	mailer PASSWORD-FILE

A shell script to send mail to all users whose passwords got cracked.
This is not always a good idea, though, since lots of people do not
check their e-mail or ignore such messages, and the messages can be a
hint for crackers.

You should probably deploy proactive password strength checking, such as
with passwdqc, before you ask users to change their passwords - whether
using this script or otherwise.  And you should edit the message inside
the script before possibly using it.

$Owl: Owl/packages/john/john/doc/OPTIONS,v 1.11 2011/11/20 00:51:35 solar Exp $