NAME
    Digest::Bcrypt - Perl interface to the bcrypt digest algorithm

SYNOPSIS
        #!/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 1 and 31
        $bcrypt->cost(12);

        # $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', 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!";
        }

NOTICE
    While maintenance for Digest::Bcrypt will continue, there's no reason to
    use Digest::Bcrypt when Crypt::Bcrypt already exists. We suggest that
    you use Crypt::Bcrypt instead.

DESCRIPTION
    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.

ATTRIBUTES
    Digest::Bcrypt implements the following attributes.

  cost
        $bcrypt = $bcrypt->cost(20); # allows for method chaining
        my $cost = $bcrypt->cost();

    An integer in the range 1..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.

  salt
        $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 octets

    Sets 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.

  type
        # method chaining on mutations as invocant is returned
        $bcrypt = $bcrypt->type('2b');
        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 considerd equivalent to "2b" and used in PHP. "2x" which
    is very broken and only needed to work with ancient PHP versions.

  settings
        $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.

METHODS
    Digest::Bcrypt inherits all methods from Digest::base and
    implements/overrides the following methods as well.

  new
        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.

  add
        $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.

  b64digest
        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.

  bcrypt_b64digest
        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.

  clone
        my $clone = $bcrypt->clone;

    Creates a clone of the "Digest::Bcrypt" object, and returns it.

  digest
        my $digest = $bcrypt->digest;

    Returns the binary digest for the message. The returned string will be
    23 bytes long.

  hexdigest
        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'.

  reset
        $bcrypt->reset;

    Resets the object to the same internal state it was in when it was
    constructed.

SEE ALSO
    Digest, Crypt::Eksblowfish::Bcrypt, Data::Entropy::Algorithms

AUTHOR
    James Aitken "jaitken@cpan.org"

CONTRIBUTORS
    *   Chase Whitener "capoeira@cpan.org"

COPYRIGHT AND LICENSE
    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.

