NAME

Authen::Passphrase::LANManager - passphrases using the LAN Manager hash algorithm

SYNOPSIS

        use Authen::Passphrase::LANManager;

        $ppr = Authen::Passphrase::LANManager->new(
                hash_hex => "855c3697d9979e78ac404c4ba2c66533");

        $ppr = Authen::Passphrase::LANManager->new(
                passphrase => "passphrase");

        $ppr = Authen::Passphrase::LANManager->from_rfc2307(
                "{LANMAN}855c3697d9979e78ac404c4ba2c66533");

        $hash = $ppr->hash;
        $hash_hex = $ppr->hash_hex;

        $ppr0 = $ppr->first_half;
        $ppr1 = $ppr->second_half;

        if($ppr->match($passphrase)) { ...

        $userPassword = $ppr->as_rfc2307;

DESCRIPTION

An object of this class encapsulates a passphrase hashed using the Microsoft LAN Manager hash function. This is a subclass of Authen::Passphrase, and this document assumes that the reader is familiar with the documentation for that class.

The hash algorithm can be used on up to fourteen Latin-1 characters of passphrase. First the passphrase is folded to uppercase, and zero-padded to fourteen bytes. Then it is split into two halves. Each seven-byte half is used as a 56-bit DES key, to encrypt the fixed plaintext block "KGS!@#$%". The eight-byte ciphertexts are concatenated to form the sixteen-byte hash. There is no salt.

Because the two halves of the passphrase are hashed separately, it is possible to manipulate (e.g., crack) a half hash in isolation. See Authen::Passphrase::LANManagerHalf.

Warning: Don't even think about using this seriously. It's an exceptionally weak design, flawed in pretty much every respect.

CONSTRUCTORS

Authen::Passphrase::LANManager->new(ATTR => VALUE, ...): Generates a new passphrase recogniser object using the LAN Manager hash algorithm. The following attributes may be given:

hash: The hash, as a string of 16 bytes.
hash_hex: The hash, as a string of 32 hexadecimal digits.
passphrase: A passphrase that will be accepted.

Either the hash or the passphrase must be given.

Authen::Passphrase::LANManager->from_rfc2307(USERPASSWORD): Generates a LAN Manager passphrase recogniser from the supplied RFC2307 encoding. The string must consist of "{LANMAN}" (or its synonym "{LANM}") followed by the hash in hexadecimal; case is ignored.

METHODS

$ppr->hash: Returns the hash value, as a string of 16 bytes.
$ppr->hash_hex: Returns the hash value, as a string of 32 hexadecimal digits.
$ppr->first_half: Returns the hash of the first half of the passphrase, as an Authen::Passphrase::LANManagerHalf passphrase recogniser.
$ppr->second_half: Returns the hash of the second half of the passphrase, as an Authen::Passphrase::LANManagerHalf passphrase recogniser.
$ppr->match(PASSPHRASE)
$ppr->as_rfc2307: These methods are part of the standard Authen::Passphrase interface.

AUTHOR

Andrew Main (Zefram) <zefram@fysh.org>

COPYRIGHT

LICENSE

This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.