Better POD

[authen-passphrase-scrypt.git] / lib / Authen / Passphrase / Scrypt.pm

diff --git a/lib/Authen/Passphrase/Scrypt.pm b/lib/Authen/Passphrase/Scrypt.pm
index 213d4136f9242c14ed6e2e3f9f39b99aa625d452..3a43e25b3632d83f0a1a9cdb3e406b86b65db56f 100644 (file)
--- a/lib/Authen/Passphrase/Scrypt.pm
+++ b/lib/Authen/Passphrase/Scrypt.pm
@@ -5,7 +5,7 @@ use strict;
 use warnings;
 use Carp;
 
-use parent qw/Exporter Authen::Passphrase Class::Accessor::Fast/;
+use parent qw/Exporter Authen::Passphrase/;
 
 our @EXPORT = qw/crypto_scrypt/;
 our @EXPORT_OK = @EXPORT;
@@ -18,7 +18,7 @@ use MIME::Base64;
 require XSLoader;
 XSLoader::load('Authen::Passphrase::Scrypt', $VERSION);
 
-__PACKAGE__->mk_accessors(qw/data logN r p salt hmac passphrase/);
+use Object::Tiny qw/data logN r p salt hmac passphrase/;
 
 sub compute_hash {
        my ($self, $passphrase) = @_;
@@ -36,19 +36,21 @@ sub truncate_hash {
 
 sub new {
        my ($class, @args) = @_;
-       my $self = $class->SUPER::new(@args);
+       if ('HASH' eq ref $args[0]) { # we were given a hash
+               @args = %{$args[0]}
+       }
+       unshift @args, logN => 14, r => 16, p => 1; # default values
+       my %args = @args;
+       $args{salt} = rand_bits 256 unless exists $args{salt};
+       my $self = bless \%args, $class;
 
-       $self->logN(14) unless defined $self->logN;
-       $self->r(16) unless defined $self->r;
-       $self->p(1) unless defined $self->p;
        croak "passphrase not set" unless defined $self->passphrase;
-       $self->salt(rand_bits 256) unless $self->salt;
 
        my $data = "scrypt\x00" . pack 'CNNa32',
          $self->logN, $self->r, $self->p, $self->salt;
        $data .= truncated_sha256 $data;
-       $self->data($data);
-       $self->hmac(hmac_sha256 $self->data, truncate_hash $self->compute_hash($self->passphrase));
+       $self->{data} = $data;
+       $self->{hmac} = hmac_sha256 $self->data, truncate_hash $self->compute_hash($self->passphrase);
        $self
 }
 
@@ -60,7 +62,7 @@ sub from_rfc2307 {
          unpack 'Z7CNNa32a16a32', $data;
        croak 'Invalid Scrypt hash: should start with "scrypt"' unless $scrypt eq 'scrypt';
        croak 'Invalid Scrypt hash: bad checksum', unless $cksum eq truncated_sha256 (substr $data, 0, 48);
-       $class->SUPER::new({data => (substr $data, 0, 64), logN => $logN, r => $r, p => $p, salt => $salt, hmac => $hmac});
+       bless { data => (substr $data, 0, 64), logN => $logN, r => $r, p => $p, salt => $salt, hmac => $hmac }, $class;
 }
 
 sub match {
@@ -96,9 +98,9 @@ Authen::Passphrase::Scrypt - passphrases using Tarsnap's scrypt algorithm
   use Authen::Passphrase::Scrypt;
 
   # Hash a password
-  my $sc = Authen::Passphrase::Scrypt->new({
+  my $sc = Authen::Passphrase::Scrypt->new(
       passphrase => 'correcthorsebatterystaple'
-  });
+  );
   my $hash = $sc->as_rfc2307;
   say "The given password hashes to $hash";
 
@@ -109,13 +111,13 @@ Authen::Passphrase::Scrypt - passphrases using Tarsnap's scrypt algorithm
   say 'The password was "xkcd"' if $sc->match('xkcd');
 
   # Advanced hashing
-  my $sc = Authen::Passphrase::Scrypt->new({
+  my $sc = Authen::Passphrase::Scrypt->new(
       passphrase => 'xkcd',
       logN       => 14, # General work factor
       r          => 16, # Memory work factor
       p          => 1,  # CPU (parallellism) work factor
       salt       => 'SodiumChloride && sODIUMcHLORIDE', # Must be 32 bytes
-  });
+  );
   say 'The given password now hashes to ', $sc->as_rfc2307;
 
 =head1 DESCRIPTION
@@ -134,10 +136,11 @@ from within L<Authen::Passphrase>. The methods are:
 
 =over
 
-=item Authen::Passphrase::Scrypt->B<new>(I<\%args>)
+=item Authen::Passphrase::Scrypt->B<new>(I<%args>)
 
 Creates a new L<Authen::Passphrase::Scrypt> from a given passphrase
-and parameters. Use this to hash a passphrase. The arguments are:
+and parameters. Use this to hash a passphrase. This function takes
+either a key value list or a hashref. The arguments are:
 
 =over
 
@@ -174,6 +177,8 @@ fine-tuning: if scrypt uses too much memory but not enough CPU,
 decrease logN and increase p; if scrypt uses too much CPU but not
 enough memory, decrease logN and increase r.
 
+Note that C<< 2^logN >> must fit in 64 bits and C<< r * p < 2^30 >>.
+
 =item $sc->B<as_rfc2307>
 
 Returns the hash of the passphrase, in RFC2307 format. This is
@@ -190,6 +195,7 @@ Returns true if the given passphrase matches the hash, false
 otherwise.
 
 =item Authen::Passphrase::Scrypt->from_crypt
+
 =item $sc->as_crypt
 
 These functions both croak. They are provided for compatibility with