updated the security guide on the updated mass-assignment security scopes addition, and assign_attributes in AR

This commit is contained in:
Josh Kalderimis 2011-04-23 15:20:19 +02:00
parent a08d04bedf
commit b3ba36830b

@ -418,10 +418,17 @@ To avoid this, Rails provides two class methods in your Active Record class to c
attr_protected :admin
</ruby>
+attr_protected+ also optionally takes a scope option using :as which allows you to define multiple mass-assignment groupings. If no scope is defined then attributes will be added to the default group.
<ruby>
attr_protected :last_login, :as => :admin
</ruby>
A much better way, because it follows the whitelist-principle, is the +attr_accessible+ method. It is the exact opposite of +attr_protected+, because _(highlight)it takes a list of attributes that will be accessible_. All other attributes will be protected. This way you won't forget to protect attributes when adding new ones in the course of development. Here is an example:
<ruby>
attr_accessible :name
attr_accessible :name, :is_admin, :as => :admin
</ruby>
If you want to set a protected attribute, you will to have to assign it individually:
@ -434,7 +441,25 @@ params[:user] # => {:name => "ow3ned", :admin => true}
@user.admin # => true
</ruby>
A more paranoid technique to protect your whole project would be to enforce that all models whitelist their accessible attributes. This can be easily achieved with a very simple initializer:
When assigning attributes in Active Record using +new+, +attributes=+, or +update_attributes+ the :default scope will be used. To assign attributes using different scopes you should use +assign_attributes+ which accepts an optional :as options parameter. If no :as option is provided then the :default scope will be used. You can also bypass mass-assignment security by using the +:without_protection+ option. Here is an example:
<ruby>
@user = User.new
@user.assign_attributes({ :name => 'Josh', :is_admin => true })
@user.name # => Josh
@user.is_admin # => false
@user.assign_attributes({ :name => 'Josh', :is_admin => true }, :as => :admin)
@user.name # => Josh
@user.is_admin # => true
@user.assign_attributes({ :name => 'Josh', :is_admin => true }, :without_protection => true)
@user.name # => Josh
@user.is_admin # => true
</ruby>
A more paranoid technique to protect your whole project would be to enforce that all models whitelist their accessible attributes. This can be easily achieved with a very simple initializer:
<ruby>
ActiveRecord::Base.send(:attr_accessible, nil)