Digest::Bcrypt - Perl interface to the bcrypt digest algorithm
#!/usr/bin/env perl
use strict;
use warnings;
use utf8;
use Digest; # via the Digest module (recommended)
my $bcrypt = Digest->new('Bcrypt', cost => 12, salt => 'abcdefgh♥stuff');
# You can forego the cost and salt in favor of settings strings:
my $bcrypt = Digest->new('Bcrypt', settings => '$2a$20$GA.eY03tb02ea0DqbA.eG.');
# $cost is an integer between 5 and 31
$bcrypt->cost(12);
# $type is a selection between 2a, 2b, 2x, and 2y
$bcrypt->type('2b');
# $salt must be exactly 16 octets long
$bcrypt->salt('abcdefgh♥stuff');
# OR, for good, random salts:
use Data::Entropy::Algorithms qw(rand_bits);
$bcrypt->salt(rand_bits(16*8)); # 16 octets
# You can forego the cost and salt in favor of settings strings:
$bcrypt->settings('$2a$20$GA.eY03tb02ea0DqbA.eG.');
# add some strings we want to make a secret of
$bcrypt->add('some stuff', 'here and', 'here');
my $digest = $bcrypt->digest;
$digest = $bcrypt->hexdigest;
$digest = $bcrypt->b64digest;
# bcrypt's own non-standard base64 dictionary
$digest = $bcrypt->bcrypt_b64digest;
# Now, let's create a password hash and check it later:
use Data::Entropy::Algorithms qw(rand_bits);
my $bcrypt = Digest->new('Bcrypt', type => '2b', cost => 20, salt => rand_bits(16*8));
my $settings = $bcrypt->settings(); # save for later checks.
my $pass_hash = $bcrypt->add('Some secret password')->digest;
# much later, we can check a password against our hash via:
my $bcrypt = Digest->new('Bcrypt', settings => $settings);
if ($bcrypt->add($value_from_user)->digest eq $known_pass_hash) {
say "Your password matched";
}
else {
say "Try again!";
}
# Now that you've seen how cumbersome/silly that is,
# please use Crypt::Bcrypt instead of this module.While maintenance for Digest::Bcrypt will continue, there's no reason to use Digest::Bcrypt when Crypt::Bcrypt already exists. We strongly suggest that you use Crypt::Bcrypt instead.
This Digest::Bcrypt interface is crufty and laborious to use when compared
to that of Crypt::Bcrypt.
Digest::Bcrypt provides a Digest-based interface to the Crypt::Bcrypt library.
Please note that you must set a salt of exactly 16 octets in length,
and you must provide a cost in the range 1..31.
Digest::Bcrypt implements the following attributes.
$bcrypt = $bcrypt->cost(20); # allows for method chaining
my $cost = $bcrypt->cost();An integer in the range 5..31, this is required.
See Crypt::Eksblowfish::Bcrypt for a detailed description of cost
in the context of the bcrypt algorithm.
When called with no arguments, it will return the current cost.
$bcrypt = $bcrypt->salt('abcdefgh♥stuff'); # allows for method chaining
my $salt = $bcrypt->salt();
# OR, for good, random salts:
use Data::Entropy::Algorithms qw(rand_bits);
$bcrypt->salt(rand_bits(16*8)); # 16 octetsSets the value to be used as a salt. Bcrypt requires exactly 16 octets of salt.
It is recommenced that you use a module like Data::Entropy::Algorithms to provide a truly randomized salt.
When called with no arguments, it will return the current salt.
$bcrypt = $bcrypt->settings('$2a$20$GA.eY03tb02ea0DqbA.eG.'); # allows for method chaining
my $settings = $bcrypt->settings();A settings string can be used to set the "salt" in Digest::Bcrypt and
"cost" in Digest::Bcrypt automatically. Setting the settings will override any
current values in your cost and salt attributes.
For details on the settings string requirements, please see Crypt::Eksblowfish::Bcrypt.
When called with no arguments, it will return the current settings string.
$bcrypt = $bcrypt->type('2b');
# method chaining on mutations
say $bcrypt->type(); # 2b
This sets the subtype of bcrypt used. These subtypes are as defined in Crypt::Bcrypt.
The available types are:
2b which is the current standard,
2a which is older; it's the one used in Crypt::Eksblowfish,
2y which is considered equivalent to 2b and used in PHP.
2x which is very broken and only needed to work with ancient PHP versions.
Digest::Bcrypt inherits all methods from Digest::base and implements/overrides the following methods as well.
my $bcrypt = Digest->new('Bcrypt', %params);
my $bcrypt = Digest::Bcrypt->new(%params);
my $bcrypt = Digest->new('Bcrypt', \%params);
my $bcrypt = Digest::Bcrypt->new(\%params);Creates a new Digest::Bcrypt object. It is recommended that you use the Digest
module in the first example rather than using Digest::Bcrypt directly.
Any of the "ATTRIBUTES" in Digest::Bcrypt above can be passed in as a parameter.
$bcrypt->add("a"); $bcrypt->add("b"); $bcrypt->add("c");
$bcrypt->add("a")->add("b")->add("c");
$bcrypt->add("a", "b", "c");
$bcrypt->add("abc");
Adds data to the message we are calculating the digest for. All the above examples have the same effect.
my $digest = $bcrypt->b64digest;Same as "digest", but will return the digest base64 encoded.
The length of the returned string will be 31 and will only contain characters
from the ranges '0'..'9', 'A'..'Z', 'a'..'z', '+', and '/'
The base64 encoded string returned is not padded to be a multiple of 4 bytes long.
my $digest = $bcrypt->bcrypt_b64digest;Same as "digest", but will return the digest base64 encoded using the alphabet that is commonly used with bcrypt.
The length of the returned string will be 31 and will only contain characters
from the ranges '0'..'9', 'A'..'Z', 'a'..'z', '+', and '.'
The base64 encoded string returned is not padded to be a multiple of 4 bytes long.
Note: This is bcrypt's own non-standard base64 alphabet, It is not compatible with the standard MIME base64 encoding.
my $clone = $bcrypt->clone;Creates a clone of the Digest::Bcrypt object, and returns it.
my $digest = $bcrypt->digest;Returns the binary digest for the message. The returned string will be 23 bytes long.
my $digest = $bcrypt->hexdigest;Same as "digest", but will return the digest in hexadecimal form.
The length of the returned string will be 46 and will only contain
characters from the ranges '0'..'9' and 'a'..'f'.
$bcrypt->reset;
Resets the object to the same internal state it was in when it was constructed.
Digest, Crypt::Eksblowfish::Bcrypt, Data::Entropy::Algorithms
James Aitken jaitken@cpan.org
- Chase Whitener
capoeira@cpan.org
This software is copyright (c) 2012 by James Aitken.
This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.