ruby-on-rails - 使用 declarative_authorization 保护敏感属性

Question

使用 declarative_authorization 按角色保护属性的好方法是什么？ ？例如，用户可以编辑他的联系信息，但不能编辑他的角色。

我的第一个想法是为不同的场景创建多个 Controller 操作。我很快意识到随着 protected 属性数量的增加，这会变得多么笨拙。为用户角色执行此操作是一回事，但我可以想象多个 protected 属性。添加很多 Controller 操作和路由感觉不对。

我的第二个倾向是围绕特定的敏感属性创建权限，然后使用 declarative_authorizations 提供的 View hepers 包装表单元素。但是，在我看来，模型和 Controller 这方面有点模糊。建议会很棒。

请建议使用 declarative_authorizations 按角色保护属性的最佳方法。

Answer 1

编辑 2011-05-22
从 3.1RC 开始，Rails 中现在有类似的东西 https://github.com/rails/rails/blob/master/activerecord/test/cases/mass_assignment_security_test.rb所以我建议现在就走那条路。

原始答案
我只需要将我以前使用的内容移植到 Rails 3。我从来没有专门使用过声明式授权，但这非常简单明了，您应该能够适应它。

添加了 Rails 3 mass_assignment_authorizer ，这让这一切变得非常简单。我以该链接教程为基础，通过类继承和将属性分组到角色中，使其更适合我的领域模型。

在模型中

acts_as_accessible :admin => :all, :moderator => [:is_spam, :is_featured]
attr_accessible :title, :body # :admin, :moderator, and anyone else can set these

在 Controller 中

post.accessed_by(current_user.roles.collect(&:code)) # or however yours works
post.attributes = params[:post]

lib/active_record/acts_as_accessible.rb

# A way to have different attr_accessible attributes based on a Role
# @see ActsAsAccessible::ActMethods#acts_as_accessible
module ActiveRecord
  module ActsAsAccessible
    module ActMethods
      # In model
      # acts_as_accessible :admin => :all, :moderator => [:is_spam]
      # attr_accessible :title, :body
      #
      # In controller
      # post.accessed_by(current_user.roles.collect(&:code))
      # post.attributes = params[:post]
      #
      # Warning: This frequently wouldn't be the concern of the model where this is declared in,
      # but it is so much more useful to have it in there with the attr_accessible declaration.
      # OHWELL.
      #
      # @param [Hash] roles Hash of { :role => [:attr, :attr] }
      # @see acts_as_accessible_attributes
      def acts_as_accessible(*roles)
        roles_attributes_hash = Hash.new {|h,k| h[k] ||= [] }
        roles_attributes_hash = roles_attributes_hash.merge(roles.extract_options!).symbolize_keys

        if !self.respond_to? :acts_as_accessible_attributes
          attr_accessible
          write_inheritable_attribute :acts_as_accessible_attributes, roles_attributes_hash.symbolize_keys
          class_inheritable_reader    :acts_as_accessible_attributes

          # extend ClassMethods unless (class << self; included_modules; end).include?(ClassMethods)
          include InstanceMethods unless included_modules.include?(InstanceMethods)
        else # subclass
          new_acts_as_accessible_attributes = self.acts_as_accessible_attributes.dup
          roles_attributes_hash.each do |role,attrs|
            new_acts_as_accessible_attributes[role] += attrs
          end
          write_inheritable_attribute :acts_as_accessible_attributes, new_acts_as_accessible_attributes.symbolize_keys
        end
      end
    end

    module InstanceMethods
      # @param [Array, NilClass] roles Array of Roles or nil to reset
      # @return [Array, NilClass]
      def accessed_by(*roles)
        if roles.any?
          case roles.first
          when NilClass
            @accessed_by = nil
          when Array
            @accessed_by = roles.first.flatten.collect(&:to_sym)
          else
            @accessed_by = roles.flatten.flatten.collect(&:to_sym)
          end
        end
        @accessed_by
      end

      private
      # This is what really does the work in attr_accessible/attr_protected.
      # This override adds the acts_as_accessible_attributes for the current accessed_by roles.
      # @see http://asciicasts.com/episodes/237-dynamic-attr-accessible
      def mass_assignment_authorizer
        attrs = []
        if self.accessed_by
          self.accessed_by.each do |role|
            if self.acts_as_accessible_attributes.include? role
              if self.acts_as_accessible_attributes[role] == :all
                return self.class.protected_attributes
              else
                attrs += self.acts_as_accessible_attributes[role]
              end
            end
          end
        end
        super + attrs
      end
    end
  end
end

ActiveRecord::Base.send(:extend, ActiveRecord::ActsAsAccessible::ActMethods)

spec/lib/active_record/acts_as_accessible.rb

require 'spec_helper'

class TestActsAsAccessible
  include ActiveModel::MassAssignmentSecurity
  extend ActiveRecord::ActsAsAccessible::ActMethods
  attr_accessor :foo, :bar, :baz, :qux
  acts_as_accessible :dude => [:bar], :bra => [:baz, :qux], :admin => :all
  attr_accessible :foo
  def attributes=(values)
    sanitize_for_mass_assignment(values).each do |k, v|
      send("#{k}=", v)
    end
  end
end

describe TestActsAsAccessible do
  it "should still allow mass assignment to accessible attributes by default" do
    subject.attributes = {:foo => 'fooo'}
    subject.foo.should == 'fooo'
  end
  it "should not allow mass assignment to non-accessible attributes by default" do
    subject.attributes = {:bar => 'baaar'}
    subject.bar.should be_nil
  end
  it "should allow mass assignment to acts_as_accessible attributes when passed appropriate accessed_by" do
    subject.accessed_by :dude
    subject.attributes = {:bar => 'baaar'}
    subject.bar.should == 'baaar'
  end
  it "should allow mass assignment to multiple acts_as_accessible attributes when passed appropriate accessed_by" do
    subject.accessed_by :bra
    subject.attributes = {:baz => 'baaaz', :qux => 'quuux'}
    subject.baz.should == 'baaaz'
    subject.qux.should == 'quuux'
  end
  it "should allow multiple accessed_by to be specified" do
    subject.accessed_by :dude, :bra
    subject.attributes = {:bar => 'baaar', :baz => 'baaaz', :qux => 'quuux'}
    subject.bar.should == 'baaar'
    subject.baz.should == 'baaaz'
    subject.qux.should == 'quuux'
  end
  it "should allow :all access" do
    subject.accessed_by :admin
    subject.attributes = {:bar => 'baaar', :baz => 'baaaz', :qux => 'quuux'}
    subject.bar.should == 'baaar'
    subject.baz.should == 'baaaz'
    subject.qux.should == 'quuux'
  end
end