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 [at] nta-monitor.com>