File Coverage

blib/lib/LINE/Bot/API/Event.pm

Criterion	Covered	Total	%
statement	76	77	98.7
branch	3	6	50.0
condition	4	6	66.6
subroutine	20	20	100.0
pod	0	2	0.0
total	103	111	92.7

package LINE::Bot::API::Event;
use strict;
use warnings;

use Carp 'carp';
our @CARP_NOT = qw( LINE::Bot::API::Event LINE::Bot::API);

use Digest::SHA 'hmac_sha256';
use JSON::XS 'decode_json';
use MIME::Base64 'decode_base64';

use LINE::Bot::API::Event::Message;
use LINE::Bot::API::Event::Follow;
use LINE::Bot::API::Event::Unfollow;
use LINE::Bot::API::Event::Join;
use LINE::Bot::API::Event::Leave;
use LINE::Bot::API::Event::MemberJoin;
use LINE::Bot::API::Event::MemberLeave;
use LINE::Bot::API::Event::Postback;
use LINE::Bot::API::Event::BeaconDetection;
use LINE::Bot::API::Event::Things;
use LINE::Bot::API::Event::AccountLink;

my %TYPE2CLASS = (
    message      => 'LINE::Bot::API::Event::Message',
    follow       => 'LINE::Bot::API::Event::Follow',
    unfollow     => 'LINE::Bot::API::Event::Unfollow',
    join         => 'LINE::Bot::API::Event::Join',
    leave        => 'LINE::Bot::API::Event::Leave',
    memberJoined => 'LINE::Bot::API::Event::MemberJoin',
    memberLeft   => 'LINE::Bot::API::Event::MemberLeave',
    postback     => 'LINE::Bot::API::Event::Postback',
    beacon       => 'LINE::Bot::API::Event::BeaconDetection',
    things       => 'LINE::Bot::API::Event::Things',
    accountLink  => 'LINE::Bot::API::Event::AccountLink',
);

sub parse_events_json {
    my($self, $json) = @_;
    my $events = [];

    my $data = decode_json $json;
    for my $event_data (@{ $data->{events} }) {
        my $type = $event_data->{type};
        my $event_class = $TYPE2CLASS{$type};
        unless ($event_class) {
            carp 'Unsupported event type: ' . $type;
        }

        my $event = $event_class->new(%{ $event_data });
        push @{ $events }, $event;
    }

    $events;
}

sub validate_signature {
    my($class, $json, $channel_secret, $signature) = @_;
    return unless $signature && $json && $channel_secret;
    my $json_signature = hmac_sha256($json, $channel_secret);
    _secure_compare(decode_base64($signature), $json_signature);
}

# Constant time string comparison for timing attacks.
sub _secure_compare {
    my($x, $y) = @_;
    return unless length $x == length $y;
    my @a = unpack 'C*', $x;
    my @b = unpack 'C*', $y;
    my $compare = 0;
    for my $i (0..(scalar(@a) - 1)) {
        $compare |= $a[$i] ^ $b[$i];
    }
    return !$compare;
}

1;
__END__