NAME
Mojolicious::Plugin::SecureCORS - Complete control over CORS
VERSION
This document describes Mojolicious::Plugin::SecureCORS version v2.0.5
SYNOPSIS
# in Mojolicious app
sub startup {
my $app = shift;
…
# load and configure
$app->plugin('SecureCORS');
$app->plugin('SecureCORS', { max_age => undef });
# set app-wide CORS defaults
$app->routes->to('cors.credentials'=>1);
# set default CORS options for nested routes
$r = $r->under(…, {'cors.origin' => '*'}, …);
# set CORS options for this route (at least "origin" option must be
# defined to allow CORS, either here or in parent routes)
$r->get(…, {'cors.origin' => '*'}, …);
$r->any(…)->to('cors.origin' => '*');
# allow non-simple (with preflight) CORS on this route
$r->cors(…);
# create under to protect all nested routes
$r = $app->routes->under_strict_cors('/resource');
DESCRIPTION
Mojolicious::Plugin::SecureCORS is a plugin that allow you to configure
Cross Origin Resource Sharing for routes in Mojolicious app.
Implements this spec: http://www.w3.org/TR/2014/REC-cors-20140116/.
SECURITY
Don't use the lazy 'cors.origin'=>'*' for resources which should be
available only for intranet or which behave differently when accessed
from intranet - otherwise malicious website opened in browser running
on workstation in intranet will get access to these resources.
Don't use the lazy 'cors.origin'=>'*' for resources which should be
available only from some known websites - otherwise other malicious
website will be able to attack your site by injecting JavaScript into
the victim's browser.
Consider using under_strict_cors() - it won't "save" you but may helps.
INTERFACE
CORS options
To allow CORS on some route you should define relevant CORS options for
that route. These options will be processed automatically using
"after_render" in Mojolicious hook and result in adding corresponding
HTTP headers to the response.
Options should be added into default parameters for the route or it
parent routes. Defining CORS options on parent route allow you to set
some predefined defaults for their nested routes.
'cors.origin' => '*'
'cors.origin' => 'null'
'cors.origin' => 'http://example.com'
'cors.origin' => 'https://example.com http://example.com:8080 null'
'cors.origin' => qr/\.local\z/ms
'cors.origin' => undef (default)
This option is required to enable CORS support for the route.
Only matched origins will be allowed to process returned response
('*' will match any origin).
When set to false value no origins will match, so it effectively
disable CORS support (may be useful if you've set this option value
on parent route).
'cors.credentials' => 1
'cors.credentials' => undef (default)
While handling preflight request true/false value will tell browser
to send or not send credentials (cookies, http auth, SSL certificate)
with actual request.
While handling simple/actual request if set to false and browser has
sent credentials will disallow to process returned response.
'cors.expose' => 'X-Some'
'cors.expose' => 'X-Some, X-Other, Server'
'cors.expose' => undef (default)
Allow access to these headers while processing returned response.
These headers doesn't need to be included in this option:
Cache-Control
Content-Language
Content-Type
Expires
Last-Modified
Pragma
'cors.headers' => 'X-Requested-With'
'cors.headers' => 'X-Requested-With, Content-Type, X-Some'
'cors.headers' => qr/\AX-|\AContent-Type\z/msi
'cors.headers' => undef (default)
Define headers which browser is allowed to send. Work only for
non-simple CORS because it require preflight.
'cors.methods' => 'POST'
'cors.methods' => 'GET, POST, PUT, DELETE'
This option can be used only for cors() route. It's needed in complex
cases when it's impossible to automatically detect CORS option while
handling preflight - see below for example.
cors
$app->routes->cors(...);
Accept same params as "any" in Mojolicious::Routes::Route.
Add handler for preflight (OPTIONS) CORS request - it's required to
allow non-simple CORS requests on given path.
To be able to respond on preflight request this handler should know
CORS options for requested method/path. In most cases it will be able
to detect them automatically by searching for route defined for same
path and HTTP method given in CORS request. Example:
$r->cors('/rpc');
$r->get('/rpc', { 'cors.origin' => 'http://example.com' });
$r->put('/rpc', { 'cors.origin' => qr/\.local\z/ms });
But in some cases target route can't be detected, for example if you've
defined several routes for same path using different conditions which
can't be checked while processing preflight request because browser
didn't sent enough information yet (like Content-Type: value which will
be used in actual request). In this case you should manually define all
relevant CORS options on preflight route - in addition to CORS options
defined on target routes. Because you can't know which one of defined
routes will be used to handle actual request, in case they use
different CORS options you should use combined in less restrictive way
options for preflight route. Example:
$r->cors('/rpc')->to(
'cors.methods' => 'GET, POST',
'cors.origin' => 'http://localhost http://example.com',
'cors.credentials' => 1,
);
$r->any([qw(GET POST)] => '/rpc',
headers => { 'Content-Type' => 'application/json-rpc' },
)->to('jsonrpc#handler',
'cors.origin' => 'http://localhost',
);
$r->post('/rpc',
headers => { 'Content-Type' => 'application/soap+xml' },
)->to('soaprpc#handler',
'cors.origin' => 'http://example.com',
'cors.credentials' => 1,
);
This route use "headers" condition, so you can add your own handler for
OPTIONS method on same path after this one, to handle non-CORS OPTIONS
requests on same path.
under_strict_cors
$route = $app->routes->under_strict_cors(...)
Accept same params as "under" in Mojolicious::Routes::Route.
Under returned route CORS requests to any route which isn't configured
for CORS (i.e. won't have 'cors.origin' in route's default parameters)
will be rendered as "403 Forbidden".
This feature should make it harder to attack your site by injecting
JavaScript into the victim's browser on vulnerable website. More
details:
https://code.google.com/p/html5security/wiki/CrossOriginRequestSecurity#Processing_rogue_COR:.
OPTIONS
Mojolicious::Plugin::SecureCORS supports the following options.
max_age
$app->plugin('SecureCORS', { max_age => undef });
Value for Access-Control-Max-Age: sent by preflight OPTIONS handler. If
set to undef this header will not be sent.
Default is 1800 (30 minutes).
METHODS
Mojolicious::Plugin::SecureCORS inherits all methods from
Mojolicious::Plugin and implements the following new ones.
register
$plugin->register(Mojolicious->new);
$plugin->register(Mojolicious->new, { max_age => undef });
Register hooks in Mojolicious application.
SEE ALSO
Mojolicious.
SUPPORT
Bugs / Feature Requests
Please report any bugs or feature requests through the issue tracker at
https://github.com/powerman/perl-Mojolicious-Plugin-SecureCORS/issues.
You will be notified automatically of any progress on your issue.
Source Code
This is open source software. The code repository is available for
public review and contribution under the terms of the license. Feel
free to fork the repository and submit pull requests.
https://github.com/powerman/perl-Mojolicious-Plugin-SecureCORS
git clone https://github.com/powerman/perl-Mojolicious-Plugin-SecureCORS.git
Resources
* MetaCPAN Search
https://metacpan.org/search?q=Mojolicious-Plugin-SecureCORS
* CPAN Ratings
http://cpanratings.perl.org/dist/Mojolicious-Plugin-SecureCORS
* AnnoCPAN: Annotated CPAN documentation
http://annocpan.org/dist/Mojolicious-Plugin-SecureCORS
* CPAN Testers Matrix
http://matrix.cpantesters.org/?dist=Mojolicious-Plugin-SecureCORS
* CPANTS: A CPAN Testing Service (Kwalitee)
http://cpants.cpanauthors.org/dist/Mojolicious-Plugin-SecureCORS
AUTHOR
Alex Efros <powerman@cpan.org>
COPYRIGHT AND LICENSE
This software is Copyright (c) 2014- by Alex Efros <powerman@cpan.org>.
This is free software, licensed under:
The MIT (X11) License