NAME

HTTP::Session2 - HTTP session management

SYNOPSIS

package MyApp;
use HTTP::Session2;

sub session {
    my $self = shift;
    if (!exists $self->{session}) {
        $self->{session} = HTTP::Session2::ClientStore->new(env => $env, secret => 'very long secret string');
    }
    $self->{session};
}

__PACKAGE__->add_trigger(
    AFTER_DISPATCH => sub {
        my ($c, $res) = @_;
        if ($c->{session}) {
            $c->{session}->finalize_plack_response($res);
        }
    },
);

DESCRIPTION

HTTP::Session2 is yet another HTTP session data management library.

RELEASE STATE

Alpha. Any API will change without notice.

MOTIVATION

We need a thrifty session management library.

What's different from HTTP::Session 1?

Generate XSRF protection token by session management library

Most of web application needs XSRF protection library.

tokuhirom guess XSRF token is closely related with session management.

Dropped StickyQuery support

In Japan, old DoCoMo's phone does not support cookie. Then, we need to support query parameter based session management.

But today, Japanese people are using smart phone :) We don't have to support legacy phones on new project.

Automatic XSRF token sending.

This is an example code for filling XSRF token. This code requires jQuery.

$(function () {
    "use strict";

    var xsrf_token = getXSRFToken();
    $("form").each(function () {
        var form = $(this);
        var method = form.attr('method');
        if (method === 'get' || method === 'GET') {
            return;
        }

        var input = $(document.createElement('input'));
        input.attr('type',  'hidden');
        input.attr('name',  'XSRF-TOKEN');
        input.attr('value',  xsrf_token);
        form.prepend(input);
    });

    function getXSRFToken() {
        var cookies = document.cookie.split(/\s*;\s*/);
        for (var i=0,l=cookies.length; i<l; i++) {
            var matched = cookies[i].match(/^XSRF-TOKEN=(.*)$/);
            if (matched) {
                return matched[1];
            }
        }
        return undefined;
    }
});

Validate XSRF token in your application

You need to call XSRF validator.

__PACKAGE__->add_trigger(
    BEFORE_DISPATCH => sub {
        my $c = shift;
        my $req = $c->req;

        if ($req->method ne 'GET' && $req->method ne 'HEAD') {
            my $xsrf_token = $req->header('X-XSRF-TOKEN') || $req->param('xsrf-token');
            unless ($session->validate_xsrf_token($xsrf_token)) {
                return [
                    403,
                    [],
                    ['XSRF detected'],
                ];
            }
        }
        return;
    }
);

pros/cons for ServerStore/ClientStore

ServerStore

pros

• It was used well.
• User can't see anything.
• You can store large data in session.

cons

• Setup is hard.

  You need to setup some configuration for your application.

ClientStore

pros

• You don't need to store anything on your server

  It makes easy to setup your server environment.

• Less server side disk

  It helps your wallet.

cons

• Security

  I hope this module is secure. Because the data was signed by HMAC. But security thing is hard.

• Session data is readable by users

  You can't store the any secret data to the session. Because this library signed to the data, but not encrypted.

• Bandwidth

  If you store the large data to the session, your session data is send to the server per every request. It may hits band-width issue. If you are writing high traffic web site, you should use server side store.

• Capacity

  Cookies are usually limited to 4096 bytes. You can't store large data to the session. You should care the cookie size, or checking cookie size by the Plack::Middleware layer.

  Ref. RFC2965

FAQ

• How can I implement "Keep me signed in" checkbox?

  You can implement it like following:

  sub dispatch_login {
      my $c = shift;
      if ($c->request->parameters->{'keep_me_signed_in'}) {
          $c->session->session_cookie->{expires} = '+1M';
      }
      $c->session->regenerate_id();
      my $user = User->login($c->request->parameters);
      $c->session->set('user_id' => $user->id);
  }
  

LICENSE

Copyright (C) tokuhirom.

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

AUTHOR

tokuhirom tokuhirom@gmail.com

CONTRIBUTORS

magai