File Coverage

blib/lib/Vigil/Token.pm

Criterion	Covered	Total	%
statement	42	42	100.0
branch	1	2	50.0
condition			n/a
subroutine	12	12	100.0
pod	2	4	50.0
total	57	60	95.0

package Vigil::Token;

use strict;
use warnings;
use 5.010;
use MIME::Base64 qw(encode_base64);
use Bytes::Random::Secure qw(random_bytes);
use Math::BigInt;

our $VERSION = '2.0.0';

sub new { bless {}, shift }

#Token of digits only
sub otp {
    my ($self) = @_;

    my $min = 100_000;
    my $max = 999_999;
    my $range = $max - $min + 1;

    my $num;
    do {
        my $bytes = random_bytes(4);          # 32-bit random
        $num = unpack("N", $bytes);           # big-endian 32-bit integer
    } while ($num >= int(2**32 / $range) * $range);  # rejection sampling

    return $num % $range + $min;
}

sub custom_token {
    my ($self, $length) = @_;
    die "custom_token requires a positive length" unless $length > 0;
    # Compute bytes needed to get at least $length Base64 chars
    my $num_bytes = int(($length * 6 + 7) / 8);  # ceil(length*6/8)
    my $bytes = random_bytes($num_bytes);
    my $token = encode_base64($bytes, '');
    $token =~ tr[+/][-_];  # Base64URL
    $token =~ s/=+$//;     # remove padding
    return substr($token, 0, $length);  # exact length
}

use overload
    '&{}' => \&as_coderef,
    fallback => 1;

sub as_coderef {
    my ($self) = @_;
    return sub {
        my @args = @_;
        return $self->custom_token(@args);
    };
}

1;

__END__