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

NAME

       Authen::Passphrase::PHPass - passphrases using the phpass algorithm

SYNOPSIS

	       use Authen::Passphrase::PHPass;

	       $ppr = Authen::Passphrase::PHPass->new(
		       cost => 10, salt => "NaClNaCl",
		       hash_base64 => "ObRxTm/.EiiYN02xUeAQs/");

	       $ppr = Authen::Passphrase::PHPass->new(
		       cost => 10, salt_random => 1,
		       passphrase => "passphrase");

	       $ppr = Authen::Passphrase::PHPass->from_crypt(
		       '$P$8NaClNaClObRxTm/.EiiYN02xUeAQs/');

	       $ppr = Authen::Passphrase::PHPass->from_rfc2307(
		       '{CRYPT}$P$8NaClNaClObRxTm/.EiiYN02xUeAQs/');

	       $cost = $ppr->cost;
	       $cost_base64 = $ppr->cost_base64;
	       $cost = $ppr->nrounds_log2;
	       $cost_base64 = $ppr->nrounds_log2_base64;
	       $salt = $ppr->salt;
	       $hash = $ppr->hash;
	       $hash_base64 = $ppr->hash_base64;

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

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

DESCRIPTION

       An object of this class encapsulates a passphrase hashed using the phpass algorithm invented by Solar Designer and described at
       <http://www.openwall.com/phpass/>.  This is a subclass of Authen::Passphrase, and this document assumes that the reader is familiar with
       the documentation for that class.

       The phpass algorithm is based on the MD5 message digest algorithm.  There is an eight-byte salt, which is conventionally restricted to
       consist of base 64 digits.  There is also a cost parameter that controls the expense of hashing.  First the salt and passphrase are
       concatenated and hashed by MD5.	Then, 2^cost times, the hash from the previous stage is concatenated with the passphrase and hashed by
       MD5.  The passphrase hash is the output from the final iteration.

       The passphrase hash is represented in ASCII using the crypt format with prefix "$P$".  The first character after the format prefix is a
       base 64 digit giving the cost parameter.  The next eight characters are the salt.  The salt is followed by 22 base 64 digits giving the
       hash.  The base 64 digits are ".", "/", "0" to "9", "A" to "Z", "a" to "z" (in ASCII order).

CONSTRUCTORS

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

	   cost
	       Base-two logarithm of the number of hashing rounds to perform.

	   cost_base64
	       Base-two logarithm of the number of hashing rounds to perform, expressed as a single base 64 digit.

	   nrounds_log2
	       Synonym for cost.

	   nrounds_log2_base64
	       Synonym for cost_base64.

	   salt
	       The salt, as an eight-byte string.

	   salt_random
	       Causes salt to be generated randomly.  The value given for this attribute is ignored.  The salt will be a string of eight base 64
	       digits.	The source of randomness may be controlled by the facility described in Data::Entropy.

	   hash
	       The hash, as a 16-byte string.

	   hash_base64
	       The hash, as a string of 22 base 64 digits.

	   passphrase
	       A passphrase that will be accepted.

	   The cost and salt must be given, and either the hash or the passphrase.

       Authen::Passphrase::PHPass->from_crypt(PASSWD)
	   Generates a new phpass passphrase recogniser object from a crypt string.  The crypt string must consist of "$P$", one base 64 character
	   encoding the cost, the salt, then 22 base 64 digits giving the hash.  The salt must be exactly 8 characters long, and cannot contain
	   any character that cannot appear in a crypt string.

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

METHODS

       $ppr->cost
	   Returns the base-two logarithm of the number of hashing rounds that will be performed.

       $ppr->cost_base64
	   Returns the base-two logarithm of the number of hashing rounds that will be performed, expressed as a single base 64 digit.

       $ppr->nrounds_log2
	   Synonym for "cost".

       $ppr->nrounds_log2_base64
	   Synonym for "cost_base64".

       $ppr->salt
	   Returns the salt, as a string of eight bytes.

       $ppr->hash
	   Returns the hash value, as a string of 16 bytes.

       $ppr->hash_base64
	   Returns the hash value, as a string of 22 base 64 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::MD5

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::PHPass(3pm)