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-rw-r--r--actionpack/lib/action_controller/request_forgery_protection.rb75
1 files changed, 41 insertions, 34 deletions
diff --git a/actionpack/lib/action_controller/request_forgery_protection.rb b/actionpack/lib/action_controller/request_forgery_protection.rb
index 75f9c0b284..beb987f7ca 100644
--- a/actionpack/lib/action_controller/request_forgery_protection.rb
+++ b/actionpack/lib/action_controller/request_forgery_protection.rb
@@ -13,33 +13,46 @@ module ActionController #:nodoc:
base.extend(ClassMethods)
end
+ # Protecting controller actions from CSRF attacks by ensuring that all forms are coming from the current web application, not a
+ # forged link from another site, is done by embedding a token based on the session (which an attacker wouldn't know) in all
+ # forms and Ajax requests generated by Rails and then verifying the authenticity of that token in the controller. Only
+ # HTML/JavaScript requests are checked, so this will not protect your XML API (presumably you'll have a different authentication
+ # scheme there anyway). Also, GET requests are not protected as these should be indempotent anyway.
+ #
+ # This is turned on with the <tt>protect_from_forgery</tt> method, which will check the token and raise an
+ # ActionController::InvalidAuthenticityToken if it doesn't match what was expected. You can customize the error message in
+ # production by editing public/422.html. A call to this method in ApplicationController is generated by default in post-Rails 2.0
+ # applications.
+ #
+ # The token parameter is named <tt>authenticity_token</tt> by default. If you are generating an HTML form manually (without the
+ # use of Rails' <tt>form_for</tt>, <tt>form_tag</tt> or other helpers), you have to include a hidden field named like that and
+ # set its value to what is returned by <tt>form_authenticity_token</tt>. Same applies to manually constructed Ajax requests. To
+ # make the token available through a global variable to scripts on a certain page, you could add something like this to a view:
+ #
+ # <%= javascript_tag "window._token = '#{form_authenticity_token}'" %>
+ #
+ # Request forgery protection is disabled by default in test environment. If you are upgrading from Rails 1.x, add this to
+ # config/environments/test.rb:
+ #
+ # # Disable request forgery protection in test environment
+ # config.action_controller.allow_forgery_protection = false
+ #
+ # == Learn more about CSRF (Cross-Site Request Forgery) attacks
+ #
+ # Here are some resources:
+ # * http://isc.sans.org/diary.html?storyid=1750
+ # * http://en.wikipedia.org/wiki/Cross-site_request_forgery
+ #
+ # Keep in mind, this is NOT a silver-bullet, plug 'n' play, warm security blanket for your rails application.
+ # There are a few guidelines you should follow:
+ #
+ # * Keep your GET requests safe and idempotent. More reading material:
+ # * http://www.xml.com/pub/a/2002/04/24/deviant.html
+ # * http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html#sec9.1.1
+ # * Make sure the session cookies that Rails creates are non-persistent. Check in Firefox and look for "Expires: at end of session"
+ #
module ClassMethods
- # Protect a controller's actions from CSRF attacks by ensuring that all forms are coming from the current web application, not
- # a forged link from another site. This is done by embedding a token based on the session (which an attacker wouldn't know) in
- # all forms and Ajax requests generated by Rails and then verifying the authenticity of that token in the controller. Only
- # HTML/JavaScript requests are checked, so this will not protect your XML API (presumably you'll have a different authentication
- # scheme there anyway). Also, GET requests are not protected as these should be indempotent anyway.
- #
- # You turn this on with the #protect_from_forgery method, which will perform the check and raise
- # an ActionController::InvalidAuthenticityToken if the token doesn't match what was expected. And it will add
- # a _authenticity_token parameter to all forms that are automatically generated by Rails. You can customize the error message
- # given through public/422.html.
- #
- # Learn more about CSRF (Cross-Site Request Forgery) attacks:
- #
- # * http://isc.sans.org/diary.html?storyid=1750
- # * http://en.wikipedia.org/wiki/Cross-site_request_forgery
- #
- # Keep in mind, this is NOT a silver-bullet, plug 'n' play, warm security blanket for your rails application.
- # There are a few guidelines you should follow:
- #
- # * Keep your GET requests safe and idempotent. More reading material:
- # * http://www.xml.com/pub/a/2002/04/24/deviant.html
- # * http://www.w3.org/Protocols/rfc2616/rfc2616-sec9.html#sec9.1.1
- # * Make sure the session cookies that Rails creates are non-persistent. Check in Firefox and look for "Expires: at end of session"
- #
- # If you need to construct a request yourself, but still want to take advantage of forgery protection, you can grab the
- # authenticity_token using the form_authenticity_token helper method and make it part of the parameters yourself.
+ # Turn on request forgery protection. Bear in mind that only non-GET, HTML/JavaScript requests are checked.
#
# Example:
#
@@ -54,16 +67,10 @@ module ActionController #:nodoc:
# skip_before_filter :verify_authenticity_token
# end
#
- # If you are upgrading from Rails 1.x, disable forgery protection to
- # simplify your tests. Add this to config/environments/test.rb:
- #
- # # Disable request forgery protection in test environment
- # config.action_controller.allow_forgery_protection = false
- #
# Valid Options:
#
- # * <tt>:only/:except</tt> - passed to the before_filter call. Set which actions are verified.
- # * <tt>:secret</tt> - Custom salt used to generate the form_authenticity_token.
+ # * <tt>:only/:except</tt> - passed to the <tt>before_filter</tt> call. Set which actions are verified.
+ # * <tt>:secret</tt> - Custom salt used to generate the <tt>form_authenticity_token</tt>.
# Leave this off if you are using the cookie session store.
# * <tt>:digest</tt> - Message digest used for hashing. Defaults to 'SHA1'
def protect_from_forgery(options = {})