NAME
psk-crack - Crack IKE Aggressive Mode Pre-Shared Keys
SYNOPSIS
psk-crack [options] <psk-parameters-file>
<psk-parameters-file> is a file containing the parameters for the pre-
shared key cracking process in the format generated by ike-scan with
the --pskcrack (-P) option. This file can contain one or more entries.
For multiple entries, each one must be on a separate line.
The program can crack either MD5 or SHA1-based hashes. The type of
hash is automatically determined from the length of the hash (16 bytes
for MD5 or 20 bytes for SHA1). Each entry in the <psk-parameters-file>
is handled separately, so it is possible to crack a mixture of MD5 and
SHA1 hashes.
psk-crack can also crack the proprietary hash format used by Nortel
Contivity / VPN Router systems. When cracking Nortel format hashes,
you need to specify the username of the hash that you are cracking with
the --norteluser (-u) option. When cracking Nortel format hashes, you
can only crack one hash at a time.
By default, psk-crack will perform dictionary cracking using the
default dictionary. The dictionary can be changed with the
--dictionary (-d) option, or brute-force cracking can be selected with
the --bruteforce (-B) option.
DESCRIPTION
psk-crack attempts to crack IKE Aggressive Mode pre-shared keys that
have previously been gathered using ike-scan with the --pskcrack
option.
psk-crack can operate in two different modes:
1) Dictionary cracking mode: this is the default mode in which psk-
crack tries each candidate word from the dictionary file in turn
until it finds a match, or all the words in the dictionary have
been tried.
2) Brute-force cracking mode: in this mode, psk-crack tries all
possible combinations of a specified character set up to a given
length.
OPTIONS
--help or -h
Display this usage message and exit.
--version or -V
Display program version and exit.
--verbose or -v
Display verbose progress messages.
--dictionary=<f> or -d <f>
Set dictionary file to <f>. The default is
/usr/local/share/ike-scan/psk-crack-dictionary.
--norteluser=<u> or -u <u>
Specify the username for Nortel Contivity cracking. This option
is required when cracking pre-shared keys on Nortel Contivity /
VPN Router systems. These systems use a proprietary method to
calculate the hash that includes the username. This option is
only needed when cracking Nortel format hashes, and should not
be used for standard format hashes.
--bruteforce=<n> or -B <n>
Select bruteforce cracking up to <n> characters.
--charset=<s> or -c <s>
Set bruteforce character set to <s> Default is
"0123456789abcdefghijklmnopqrstuvwxyz"
AUTHOR
Roy Hills <Roy.Hills@nta-monitor.com>
February 14, 2005