Authen::Passphrase::LANManagerHalf(3pm) 		User Contributed Perl Documentation		   Authen::Passphrase::LANManagerHalf(3pm)

NAME

       Authen::Passphrase::LANManagerHalf - passphrases using half the LAN Manager algorithm

SYNOPSIS

	       use Authen::Passphrase::LANManagerHalf;

	       $ppr = Authen::Passphrase::LANManagerHalf->new(
		       hash_hex => "855c3697d9979e78");

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

	       $ppr = Authen::Passphrase::LANManagerHalf->from_crypt(
		       '$LM$855c3697d9979e78');

	       $ppr = Authen::Passphrase::LANManagerHalf->from_rfc2307(
		       '{CRYPT}$LM$855c3697d9979e78');

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

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

	       $passwd = $ppr->as_crypt;
	       $userPassword = $ppr->as_rfc2307;

DESCRIPTION

       An object of this class encapsulates half of 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.  For the complete LAN
       Manager hash function, see Authen::Passphrase::LANManager.

       In a spectacularly bad design decision, the Microsoft LAN Manager hash function splits the passphrase into two parts and hashes them
       separately.  It is therefore possible to separate the halves of a LAN Manager hash, and do things with them (such as crack them)
       separately.  This class is about using such a hash half on its own.

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

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

CONSTRUCTORS

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

	   hash
	       The hash, as a string of 8 bytes.

	   hash_hex
	       The hash, as a string of 16 hexadecimal digits.

	   passphrase
	       A passphrase that will be accepted.

	   Either the hash or the passphrase must be given.

       Authen::Passphrase::LANManagerHalf->from_crypt(PASSWD)
	   Generates a new LAN Manager half passphrase recogniser object from a crypt string.  The crypt string must consist of "$LM$" followed by
	   the hash in lowercase hexadecimal.

       Authen::Passphrase::LANManagerHalf->from_rfc2307(USERPASSWORD)
	   Generates a new LAN Manager half passphrase recogniser object from an RFC 2307 string.  The string must consist of "{CRYPT}" (case
	   insensitive) followed by an acceptable crypt string.

METHODS

       $ppr->hash
	   Returns the hash value, as a string of 8 bytes.

       $ppr->hash_hex
	   Returns the hash value, as a string of 16 hexadecimal digits.

       $ppr->match(PASSPHRASE)
       $ppr->as_crypt
       $ppr->as_rfc2307
	   These methods are part of the standard Authen::Passphrase interface.

SEE ALSO

       Authen::Passphrase, Authen::Passphrase::LANManager, Crypt::DES

AUTHOR

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

COPYRIGHT

       Copyright (C) 2006, 2007, 2009, 2010, 2012 Andrew Main (Zefram) <zefram@fysh.org>

LICENSE

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

perl v5.14.2							    2012-02-07				   Authen::Passphrase::LANManagerHalf(3pm)