A HTTP feature policy is Yet Another HTTP header for instructing the
browser about which features the application intends to make use of and
to lock down access to others. This is a new security mechanism that
ensures that should an application become compromised or a third party
attempts an unexpected action, the browser will override it and maintain
the intended UX.
WICG specification: https://wicg.github.io/feature-policy/
The end result is a HTTP header that looks like the following:
```
Feature-Policy: geolocation 'none'; autoplay https://example.com
```
This will prevent the browser from using geolocation and only allow
autoplay on `https://example.com`. Full feature list can be found over
in the WICG repository[1].
As of today Chrome and Safari have public support[2] for this
functionality with Firefox working on support[3] and Edge still pending
acceptance of the suggestion[4].
#### Examples
Using an initializer
```rb
# config/initializers/feature_policy.rb
Rails.application.config.feature_policy do |f|
f.geolocation :none
f.camera :none
f.payment "https://secure.example.com"
f.fullscreen :self
end
```
In a controller
```rb
class SampleController < ApplicationController
def index
feature_policy do |f|
f.geolocation "https://example.com"
end
end
end
```
Some of you might realise that the HTTP feature policy looks pretty
close to that of a Content Security Policy; and you're right. So much so
that I used the Content Security Policy DSL from #31162 as the starting
point for this change.
This change *doesn't* introduce support for defining a feature policy on
an iframe and this has been intentionally done to split the HTTP header
and the HTML element (`iframe`) support. If this is successful, I'll
look to add that on it's own.
Full documentation on HTTP feature policies can be found at
https://wicg.github.io/feature-policy/. Google have also published[5] a
great in-depth write up of this functionality.
[1]: https://github.com/WICG/feature-policy/blob/master/features.md
[2]: https://www.chromestatus.com/feature/5694225681219584
[3]: https://bugzilla.mozilla.org/show_bug.cgi?id=1390801
[4]: https://wpdev.uservoice.com/forums/257854-microsoft-edge-developer/suggestions/33507907-support-feature-policy
[5]: https://developers.google.com/web/updates/2018/06/feature-policy
Actionable errors let's you dispatch actions from Rails' error pages. This
can help you save time if you have a clear action for the resolution of
common development errors.
The de-facto example are pending migrations. Every time pending migrations
are found, a middleware raises an error. With actionable errors, you can
run the migrations right from the error page. Other examples include Rails
plugins that need to run a rake task to setup themselves. They can now
raise actionable errors to run the setup straight from the error pages.
Here is how to define an actionable error:
```ruby
class PendingMigrationError < MigrationError #:nodoc:
include ActiveSupport::ActionableError
action "Run pending migrations" do
ActiveRecord::Tasks::DatabaseTasks.migrate
end
end
```
To make an error actionable, include the `ActiveSupport::ActionableError`
module and invoke the `action` class macro to define the action. An action
needs a name and a procedure to execute. The name is shown as the name of a
button on the error pages. Once clicked, it will invoke the given
procedure.
The ActionDispatch::HostAuthorization is a new middleware that prevent
against DNS rebinding and other Host header attacks. By default it is
included only in the development environment with the following
configuration:
Rails.application.config.hosts = [
IPAddr.new("0.0.0.0/0"), # All IPv4 addresses.
IPAddr.new("::/0"), # All IPv6 addresses.
"localhost" # The localhost reserved domain.
]
In other environments, `Rails.application.config.hosts` is empty and no
Host header checks will be done. If you want to guard against header
attacks on production, you have to manually permit the allowed hosts
with:
Rails.application.config.hosts << "product.com"
The host of a request is checked against the hosts entries with the case
operator (#===), which lets hosts support entries of type RegExp,
Proc and IPAddr to name a few. Here is an example with a regexp.
# Allow requests from subdomains like `www.product.com` and
# `beta1.product.com`.
Rails.application.config.hosts << /.*\.product\.com/
A special case is supported that allows you to permit all sub-domains:
# Allow requests from subdomains like `www.product.com` and
# `beta1.product.com`.
Rails.application.config.hosts << ".product.com"
* Move system tests back into Action Pack
* Rename `ActionSystemTest` to `ActionDispatch::SystemTestCase`
* Remove private base module and only make file for public
`SystemTestCase` class, name private module `SystemTesting`
* Rename `ActionSystemTestCase` to `ApplicationSystemTestCase`
* Update corresponding documentation and guides
* Delete old `ActionSystemTest` files
ActionDispatch::ParamsParser class was removed in favor of
ActionDispatch::Http::Parameters so it is better to move the error
constant to the new class.
These should allow external code to run blocks of user code to do
"work", at a similar unit size to a web request, without needing to get
intimate with ActionDipatch.
MessageEncryptor has :serializer option, where any serializer object can
be passed. This commit make it possible to set this serializer from configuration
level.
There are predefined serializers (:marshal_serializer, :json_serialzier)
and custom serializer can be passed as String, Symbol (camelized and
constantized in ActionDispatch::Session namepspace) or serializer object.
Default :json_serializer was also added to generators to provide secure
defalt.
Move the Journey code underneath the ActionDispatch namespace so
that we don't pollute the global namespace with names that may
be used for models.
Fixesrails/journey#49.
This allows easy upgrading from the old signed Cookie Store <= 3.2
or the deprecated one in 4.0 (the ones that doesn't use key derivation)
to the new one that signs using key derivation
AV::Template::Types is a small abstraction to allow to specify template types
that can be used in ActionView. When Action Pack is loaded it's replaced with
Mime::Type.
default_formats array is used by LookupContext in order to allow
rendering templates when :formats option is not passed. Previously it
was always set to Mime::SET, which created dependency on Action Pack. In
order to remove this dependency, Mime::SET is used only if
ActionController is loaded.
The new option allows any Ruby namespace to be registered and set
up for eager load. We are effectively exposing the structure existing
in Rails since v3.0 for all developers in order to make their applications
thread-safe and CoW friendly.
Since we removed the ActiveModel dependenxy from ActionPack at
166dbaa7526a96fdf046f093f25b0a134b277a68 we don't need to require it
anymore.
Closes#7370
This is a private place to put those AS features that are used
by every component. Nowadays we cherry-pick individual files
wherever they are used, but that it is not worth the effort
for stuff that is going to be loaded for sure sooner or later,
like blank?, autoload, concern, etc.
