Authen::Passphrase::NTHash(3)

NAME
Authen::Passphrase::NTHash - passphrases using the NT-Hash algorithm

SYNOPSIS
        use Authen::Passphrase::NTHash;

        $ppr = Authen::Passphrase::NTHash->new(
                hash_hex => "7f8fe03093cc84b267b109625f6bbf4b");

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

        $ppr = Authen::Passphrase::NTHash->from_crypt(
                '$3$$7f8fe03093cc84b267b109625f6bbf4b');

        $ppr = Authen::Passphrase::NTHash->from_rfc2307(
                '{MSNT}7f8fe03093cc84b267b109625f6bbf4b');

        $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 a passphrase hashed using the NT-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 NT-Hash scheme is based on the MD4 digest algorithm. Up to 128 characters of passphrase (characters beyond the 128th are ignored) are represented in Unicode, and hashed using MD4. No salt is used.

Warning: MD4 is a weak hash algorithm by current standards, and the lack of salt is a design flaw in this scheme. Use this for compatibility only, not by choice.

CONSTRUCTORS

Authen::Passphrase::NTHash->new(ATTR => VALUE, ...)
    Generates a new passphrase recogniser object using the NT-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::NTHash->from_crypt(PASSWD)
    Generates a new NT-Hash passphrase recogniser object from a crypt string. Two forms are accepted. In the first form, the he crypt string must consist of "$3$$" (note the extra "$") followed by the hash in lowercase hexadecimal. In the second form, the he crypt string must consist of "$NT$" followed by the hash in lowercase hexadecimal.

Authen::Passphrase::NTHash->from_rfc2307(USERPASSWORD)
    Generates a new NT-Hash passphrase recogniser object from an RFC 2307 string. Two forms are accepted. In the first form, the string must consist of "{MSNT}" followed by the hash in hexadecimal; case is ignored. In the second form, 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 16 bytes.

$ppr->hash_hex
    Returns the hash value, as a string of 32 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, Digest::MD4

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.