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.
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:
- 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.
- Brute-force cracking mode: in this mode, psk-crack tries all possible combinations of a specified character set up to a given length.