NAME

Authen::Passphrase::SaltedDigest - passphrases using the generic salted digest algorithm

SYNOPSIS

use Authen::Passphrase::SaltedDigest;

$ppr = Authen::Passphrase::SaltedDigest->new(
	algorithm => "SHA-1", salt => "my",
	hash_hex => "301ce40d1b5ceb0919c9".
		    "f26e1d7aff880a886f7b");

$algorithm = $ppr->algorithm;
$salt = $ppr->salt;
$salt_hex = $ppr->salt_hex;
$hash = $ppr->hash;
$hash_hex = $ppr->hash_hex;

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

$userPassword = $ppr->as_rfc2307;

DESCRIPTION

An object of this class encapsulates a passphrase hashed using a generic digest-algorithm-based scheme. This is a subclass of Authen::Passphrase, and this document assumes that the reader is familiar with the documentation for that class.

The salt is an arbitrary string of bytes. It is appended to passphrase, and the combined string is passed through a specified message digest algorithm. The output of the message digest algorithm is the passphrase hash.

The use of this passphrase scheme is recommended for new systems. The strength depends entirely on the choice of digest algorithm, so choose according to the level of security required. SHA-1 is suitable for most applications, but recent work has revealed weaknesses in the basic structure of MD5, SHA-1, SHA-256, and all similar digest algorithms. A new generation of digest algorithms will probably emerge sometime around 2008.

CONSTRUCTOR

Authen::Passphrase::SaltedDigest->new(ATTR => VALUE, ...)

Generates a new passphrase recogniser object using the generic salted digest algorithm. The following attributes may be given:

algorithm

A string identifying the message digest algorithm to use. It must be understood by Digest->new.

salt

The salt, as a raw string of bytes. Defaults to the empty string, yielding an unsalted scheme.

salt_hex

The salt, as a string of hexadecimal digits. Defaults to the empty string, yielding an unsalted scheme.

hash

The hash, as a string of bytes.

hash_hex

The hash, as a string of hexadecimal digits.

The digest algorithm and hash must both be given.

METHODS

$ppr->algorithm

Returns the digest algorithm, as a string that can be passed to Digest->new.

$ppr->salt

Returns the salt, in raw form.

$ppr->salt_hex

Returns the salt, as a string of hexadecimal digits.

$ppr->hash

Returns the hash value, in raw form.

$ppr->hash_hex

Returns the hash value, as a string of hexadecimal digits.

$ppr->match(PASSPHRASE)

$ppr->as_rfc2307

These methods are part of the standard Authen::Passphrase interface. Only passphrase recognisers using certain well-known digest algorithms can be represented in RFC 2307 form.

SEE ALSO

Authen::Passphrase, Crypt::Passwd

AUTHOR

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

COPYRIGHT

Copyright (C) 2006 Andrew Main (Zefram) <zefram@fysh.org>

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