Generate temp links

temp_links.pl

#!/usr/bin/env perl

use common::sense;
use lib '/tk/mojo/lib';

package TempLink;

use Mojo::Util qw(b64_decode b64_encode hmac_md5_sum secure_compare);
use Mojo::JSON;

my $expires = 60*60;# 1 hour by default
my $secret  = 'packman';
my $JSON    = Mojo::JSON->new;

sub value {
    my $value  = shift || return;
    my $secret = shift || $secret;
    
    my $data;
    if ($value =~ s/\-\-([^\-]+)$//) {
        my $sig = $1;
        my $check = hmac_md5_sum $value, $secret;
        
        # Verified
        if (secure_compare $sig, $check) {
            $value =~ s/\-/\=/g;
            $data =  $JSON->decode(b64_decode($value))
        }
    }
    
    return $data;
}

sub sign {
    my $data = {@_};
    
    return unless $data->{filename};
    
    my $secret_word  = delete $data->{secret} || $secret;
    $data->{expires} = time + $data->{expires} || $expires;
    
    my $value = $JSON->encode($data);
    b64_encode $value, '';
    $value =~ s/\=/\-/g;
    
    join '--', $value, hmac_md5_sum($value, $secret_word);
}

package main;

use Data::Dumper;

my $secret = 'some word';
my $sign = TempLink::sign(
    filename => 'somefile.zip',
    expires  => 60*60*24,
    secret   => $secret,
    user_id  => 123,
);

say $sign;

# valid
say Dumper( TempLink::value($sign, $secret) );
# failed
say Dumper( TempLink::value($sign.'-', $secret) );

1;