Authen::Passphrase::LANManager3pm

Usage

        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;

Overview

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.