]>
iEval git - authen-passphrase-scrypt.git/blob - lib/Authen/Passphrase/Scrypt.pm
1 package Authen
:: Passphrase
:: Scrypt
;
8 use parent qw
/Exporter Authen::Passphrase/ ;
10 our @EXPORT = qw
/crypto_scrypt/ ;
11 our @EXPORT_OK = @EXPORT ;
12 our $VERSION = '0.001001' ;
14 use Data
:: Entropy
:: Algorithms qw
/rand_bits/ ;
15 use Digest
:: SHA qw
/sha256 hmac_sha256/ ;
19 XSLoader
:: load
( 'Authen::Passphrase::Scrypt' , $VERSION );
21 use Object
:: Tiny qw
/data logN r p salt hmac passphrase/ ;
24 my ( $self , $passphrase ) = @_ ;
25 crypto_scrypt
( $passphrase , $self -> salt , ( 1 << $self -> logN ), $self -> r , $self -> p , 64 );
28 sub truncated_sha256
{
29 my $sha = sha256
shift ;
38 my ( $class , @args ) = @_ ;
39 if ( 'HASH' eq ref $args [ 0 ]) { # we were given a hash
42 unshift @args , logN
=> 14 , r
=> 16 , p
=> 1 ; # default values
44 $args { salt
} = rand_bits
256 unless exists $args { salt
};
45 my $self = bless \
%args , $class ;
47 croak
"passphrase not set" unless defined $self -> passphrase ;
49 my $data = "scrypt \x00 " . pack 'CNNa32' ,
50 $self -> logN , $self -> r , $self -> p , $self -> salt ;
51 $data .= truncated_sha256
$data ;
52 $self ->{ data
} = $data ;
53 $self ->{ hmac
} = hmac_sha256
$self -> data , truncate_hash
$self -> compute_hash ( $self -> passphrase );
58 my ( $class , $rfc2307 ) = @_ ;
59 croak
"Invalid Scrypt RFC2307" unless $rfc2307 =~ m
,^{ SCRYPT
}([ A
- Za
- z0
- 9 +/]{ 128 })$,;
60 my $data = decode_base64
$1 ;
61 my ( $scrypt , $logN , $r , $p , $salt , $cksum , $hmac ) =
62 unpack 'Z7CNNa32a16a32' , $data ;
63 croak
'Invalid Scrypt hash: should start with "scrypt"' unless $scrypt eq 'scrypt' ;
64 croak
'Invalid Scrypt hash: bad checksum' , unless $cksum eq truncated_sha256
( substr $data , 0 , 48 );
65 bless { data
=> ( substr $data , 0 , 64 ), logN
=> $logN , r
=> $r , p
=> $p , salt
=> $salt , hmac
=> $hmac }, $class ;
69 my ( $self , $passphrase ) = @_ ;
70 my $correct_hmac = hmac_sha256
$self -> data , truncate_hash
$self -> compute_hash ( $passphrase );
71 $self -> hmac eq $correct_hmac
76 '{SCRYPT}' . encode_base64
( $self -> data . $self -> hmac , '' )
80 croak __PACKAGE__
. " does not support crypt strings, use from_rfc2307 instead" ;
84 croak __PACKAGE__
. " does not support crypt strings, use as_rfc2307 instead" ;
94 Authen::Passphrase::Scrypt - passphrases using Tarsnap's scrypt algorithm
98 use Authen::Passphrase::Scrypt;
101 my $sc = Authen::Passphrase::Scrypt->new({
102 passphrase => 'correcthorsebatterystaple'
104 my $hash = $sc->as_rfc2307;
105 say "The given password hashes to $hash";
108 $sc = Authen::Passphrase::Scrypt->from_rfc2307($hash);
109 say 'The password was "correcthorsebatterystaple"'
110 if $sc->match('correcthorsebatterystaple');
111 say 'The password was "xkcd"' if $sc->match('xkcd');
114 my $sc = Authen::Passphrase::Scrypt->new({
115 passphrase => 'xkcd',
116 logN => 14, # General work factor
117 r => 16, # Memory work factor
118 p => 1, # CPU (parallellism) work factor
119 salt => 'SodiumChloride && sODIUMcHLORIDE', # Must be 32 bytes
121 say 'The given password now hashes to ', $sc->as_rfc2307;
125 B<This is experimental code, DO NOT USE in security-critical software>.
127 Scrypt is a key derivation function that was originally developed for
128 use in the Tarsnap online backup system and is designed to be far more
129 secure against hardware brute-force attacks than alternative functions
130 such as PBKDF2 or bcrypt.
132 Authen::Passphrase::Scrypt is a module for hashing and verifying
133 passphrases using scrypt. It offers the same interface as
134 L<Authen::Passphrase>. It is not however possible to use this module
135 from within L<Authen::Passphrase>. The methods are:
139 =item Authen::Passphrase::Scrypt->B<new>(I<\%args>)
141 Creates a new L<Authen::Passphrase::Scrypt> from a given passphrase
142 and parameters. Use this to hash a passphrase. The arguments are:
148 The passphrase. Mandatory.
152 The general work factor (affects both CPU and memory cost). Defaults to 14
156 The blocksize (affects memory cost). Defaults to 16.
160 The parallelization factor (affects CPU cost). Defaults to 1.
164 A 32-byte string used as a salt. By default it is randomly generated
165 using L<Data::Entropy>.
169 All of the parameters change the result of the hash. They are all
170 stored in the hash, so there is no need to store them separately (or
171 provide them to the hash verification methods).
173 It is normally sufficient to only use the B<logN> parameter to control
174 the speed of scrypt. B<r> and B<p> are intended to be used only for
175 fine-tuning: if scrypt uses too much memory but not enough CPU,
176 decrease logN and increase p; if scrypt uses too much CPU but not
177 enough memory, decrease logN and increase r.
179 =item $sc->B<as_rfc2307>
181 Returns the hash of the passphrase, in RFC2307 format. This is
182 "{SCRYPT}" followed by the base64-encoded 96-byte result described here: L<https://security.stackexchange.com/questions/88678/why-does-node-js-scrypt-function-use-hmac-this-way/91050>
184 =item Authen::Passphrase::Scrypt->B<from_rfc2307>(I<$rfc2307>)
186 Creates a new L<Authen::Passphrase::Scrypt> from a hash in RFC2307
187 format. Use this to verify if a passphrase matches a hash.
189 =item $sc->B<match>(I<$passphrase>)
191 Returns true if the given passphrase matches the hash, false
194 =item Authen::Passphrase::Scrypt->from_crypt
197 These functions both croak. They are provided for compatibility with
198 the Authen::Passphrase interface.
204 L<Authen::Passphrase>,
205 L<https://www.tarsnap.com/scrypt.html>,
206 L<https://www.npmjs.com/package/scrypt>
210 Marius Gavrilescu, E<lt>marius@ieval.roE<gt>
212 =head1 COPYRIGHT AND LICENSE
214 Copyright (C) 2017 by Marius Gavrilescu
216 This library is free software; you can redistribute it and/or modify
217 it under the same terms as Perl itself, either Perl version 5.24.1 or,
218 at your option, any later version of Perl 5 you may have available.
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