require 'active_support/core_ext/hash/keys' require 'active_support/core_ext/object/blank' module ActionDispatch module Session # This cookie-based session store is the Rails default. Sessions typically # contain at most a user_id and flash message; both fit within the 4K cookie # size limit. Cookie-based sessions are dramatically faster than the # alternatives. # # If you have more than 4K of session data or don't want your data to be # visible to the user, pick another session store. # # CookieOverflow is raised if you attempt to store more than 4K of data. # # A message digest is included with the cookie to ensure data integrity: # a user cannot alter his +user_id+ without knowing the secret key # included in the hash. New apps are generated with a pregenerated secret # in config/environment.rb. Set your own for old apps you're upgrading. # # Session options: # # * :secret: An application-wide key string or block returning a # string called per generated digest. The block is called with the # CGI::Session instance as an argument. It's important that the secret # is not vulnerable to a dictionary attack. Therefore, you should choose # a secret consisting of random numbers and letters and more than 30 # characters. Examples: # # :secret => '449fe2e7daee471bffae2fd8dc02313d' # :secret => Proc.new { User.current_user.secret_key } # # * :digest: The message digest algorithm used to verify session # integrity defaults to 'SHA1' but may be any digest provided by OpenSSL, # such as 'MD5', 'RIPEMD160', 'SHA256', etc. # # To generate a secret key for an existing application, run # "rake secret" and set the key in config/environment.rb. # # Note that changing digest or secret invalidates all existing sessions! class CookieStore < AbstractStore def initialize(app, options = {}) super(app, options.merge!(:cookie_only => true)) freeze end private def load_session(env) data = unpacked_cookie_data(env) data = persistent_session_id!(data) [data["session_id"], data] end def extract_session_id(env) if data = unpacked_cookie_data(env) data["session_id"] else nil end end def unpacked_cookie_data(env) env["action_dispatch.request.unsigned_session_cookie"] ||= begin request = ActionDispatch::Request.new(env) if data = request.cookie_jar.signed[@key] data.stringify_keys! end data || {} end end def set_cookie(request, options) request.cookie_jar.signed[@key] = options end def set_session(env, sid, session_data) persistent_session_id!(session_data, sid) end def destroy(env) # session data is stored on client; nothing to do here end def persistent_session_id!(data, sid=nil) data ||= {} data["session_id"] ||= sid || generate_sid data end end end end