Permalink
Fetching contributors…
Cannot retrieve contributors at this time
448 lines (362 sloc) 13.3 KB
# frozen_string_literal: true
# AUTHOR: blink <blinketje@gmail.com>; blink#ruby-lang@irc.freenode.net
# bugrep: Andreas Zehnder
require 'rack'
require 'time'
require 'rack/request'
require 'rack/response'
require 'securerandom'
module Rack
module Session
module Abstract
# SessionHash is responsible to lazily load the session from store.
class SessionHash
include Enumerable
attr_writer :id
Unspecified = Object.new
def self.find(req)
req.get_header RACK_SESSION
end
def self.set(req, session)
req.set_header RACK_SESSION, session
end
def self.set_options(req, options)
req.set_header RACK_SESSION_OPTIONS, options.dup
end
def initialize(store, req)
@store = store
@req = req
@loaded = false
end
def id
return @id if @loaded or instance_variable_defined?(:@id)
@id = @store.send(:extract_session_id, @req)
end
def options
@req.session_options
end
def each(&block)
load_for_read!
@data.each(&block)
end
def [](key)
load_for_read!
@data[key.to_s]
end
def fetch(key, default = Unspecified, &block)
load_for_read!
if default == Unspecified
@data.fetch(key.to_s, &block)
else
@data.fetch(key.to_s, default, &block)
end
end
def has_key?(key)
load_for_read!
@data.has_key?(key.to_s)
end
alias :key? :has_key?
alias :include? :has_key?
def []=(key, value)
load_for_write!
@data[key.to_s] = value
end
alias :store :[]=
def clear
load_for_write!
@data.clear
end
def destroy
clear
@id = @store.send(:delete_session, @req, id, options)
end
def to_hash
load_for_read!
@data.dup
end
def update(hash)
load_for_write!
@data.update(stringify_keys(hash))
end
alias :merge! :update
def replace(hash)
load_for_write!
@data.replace(stringify_keys(hash))
end
def delete(key)
load_for_write!
@data.delete(key.to_s)
end
def inspect
if loaded?
@data.inspect
else
"#<#{self.class}:0x#{self.object_id.to_s(16)} not yet loaded>"
end
end
def exists?
return @exists if instance_variable_defined?(:@exists)
@data = {}
@exists = @store.send(:session_exists?, @req)
end
def loaded?
@loaded
end
def empty?
load_for_read!
@data.empty?
end
def keys
load_for_read!
@data.keys
end
def values
load_for_read!
@data.values
end
private
def load_for_read!
load! if !loaded? && exists?
end
def load_for_write!
load! unless loaded?
end
def load!
@id, session = @store.send(:load_session, @req)
@data = stringify_keys(session)
@loaded = true
end
def stringify_keys(other)
hash = {}
other.each do |key, value|
hash[key.to_s] = value
end
hash
end
end
# ID sets up a basic framework for implementing an id based sessioning
# service. Cookies sent to the client for maintaining sessions will only
# contain an id reference. Only #find_session and #write_session are
# required to be overwritten.
#
# All parameters are optional.
# * :key determines the name of the cookie, by default it is
# 'rack.session'
# * :path, :domain, :expire_after, :secure, and :httponly set the related
# cookie options as by Rack::Response#set_cookie
# * :skip will not a set a cookie in the response nor update the session state
# * :defer will not set a cookie in the response but still update the session
# state if it is used with a backend
# * :renew (implementation dependent) will prompt the generation of a new
# session id, and migration of data to be referenced at the new id. If
# :defer is set, it will be overridden and the cookie will be set.
# * :sidbits sets the number of bits in length that a generated session
# id will be.
#
# These options can be set on a per request basis, at the location of
# <tt>env['rack.session.options']</tt>. Additionally the id of the
# session can be found within the options hash at the key :id. It is
# highly not recommended to change its value.
#
# Is Rack::Utils::Context compatible.
#
# Not included by default; you must require 'rack/session/abstract/id'
# to use.
class Persisted
DEFAULT_OPTIONS = {
key: RACK_SESSION,
path: '/',
domain: nil,
expire_after: nil,
secure: false,
httponly: true,
defer: false,
renew: false,
sidbits: 128,
cookie_only: true,
secure_random: ::SecureRandom
}.freeze
attr_reader :key, :default_options, :sid_secure
def initialize(app, options = {})
@app = app
@default_options = self.class::DEFAULT_OPTIONS.merge(options)
@key = @default_options.delete(:key)
@cookie_only = @default_options.delete(:cookie_only)
initialize_sid
end
def call(env)
context(env)
end
def context(env, app = @app)
req = make_request env
prepare_session(req)
status, headers, body = app.call(req.env)
res = Rack::Response::Raw.new status, headers
commit_session(req, res)
[status, headers, body]
end
private
def make_request(env)
Rack::Request.new env
end
def initialize_sid
@sidbits = @default_options[:sidbits]
@sid_secure = @default_options[:secure_random]
@sid_length = @sidbits / 4
end
# Generate a new session id using Ruby #rand. The size of the
# session id is controlled by the :sidbits option.
# Monkey patch this to use custom methods for session id generation.
def generate_sid(secure = @sid_secure)
if secure
secure.hex(@sid_length)
else
"%0#{@sid_length}x" % Kernel.rand(2**@sidbits - 1)
end
rescue NotImplementedError
generate_sid(false)
end
# Sets the lazy session at 'rack.session' and places options and session
# metadata into 'rack.session.options'.
def prepare_session(req)
session_was = req.get_header RACK_SESSION
session = session_class.new(self, req)
req.set_header RACK_SESSION, session
req.set_header RACK_SESSION_OPTIONS, @default_options.dup
session.merge! session_was if session_was
end
# Extracts the session id from provided cookies and passes it and the
# environment to #find_session.
def load_session(req)
sid = current_session_id(req)
sid, session = find_session(req, sid)
[sid, session || {}]
end
# Extract session id from request object.
def extract_session_id(request)
sid = request.cookies[@key]
sid ||= request.params[@key] unless @cookie_only
sid
end
# Returns the current session id from the SessionHash.
def current_session_id(req)
req.get_header(RACK_SESSION).id
end
# Check if the session exists or not.
def session_exists?(req)
value = current_session_id(req)
value && !value.empty?
end
# Session should be committed if it was loaded, any of specific options like :renew, :drop
# or :expire_after was given and the security permissions match. Skips if skip is given.
def commit_session?(req, session, options)
if options[:skip]
false
else
has_session = loaded_session?(session) || forced_session_update?(session, options)
has_session && security_matches?(req, options)
end
end
def loaded_session?(session)
!session.is_a?(session_class) || session.loaded?
end
def forced_session_update?(session, options)
force_options?(options) && session && !session.empty?
end
def force_options?(options)
options.values_at(:max_age, :renew, :drop, :defer, :expire_after).any?
end
def security_matches?(request, options)
return true unless options[:secure]
request.ssl?
end
# Acquires the session from the environment and the session id from
# the session options and passes them to #write_session. If successful
# and the :defer option is not true, a cookie will be added to the
# response with the session's id.
def commit_session(req, res)
session = req.get_header RACK_SESSION
options = session.options
if options[:drop] || options[:renew]
session_id = delete_session(req, session.id || generate_sid, options)
return unless session_id
end
return unless commit_session?(req, session, options)
session.send(:load!) unless loaded_session?(session)
session_id ||= session.id
session_data = session.to_hash.delete_if { |k, v| v.nil? }
if not data = write_session(req, session_id, session_data, options)
req.get_header(RACK_ERRORS).puts("Warning! #{self.class.name} failed to save session. Content dropped.")
elsif options[:defer] and not options[:renew]
req.get_header(RACK_ERRORS).puts("Deferring cookie for #{session_id}") if $VERBOSE
else
cookie = Hash.new
cookie[:value] = data
cookie[:expires] = Time.now + options[:expire_after] if options[:expire_after]
cookie[:expires] = Time.now + options[:max_age] if options[:max_age]
set_cookie(req, res, cookie.merge!(options))
end
end
public :commit_session
# Sets the cookie back to the client with session id. We skip the cookie
# setting if the value didn't change (sid is the same) or expires was given.
def set_cookie(request, res, cookie)
if request.cookies[@key] != cookie[:value] || cookie[:expires]
res.set_cookie_header =
Utils.add_cookie_to_header(res.set_cookie_header, @key, cookie)
end
end
# Allow subclasses to prepare_session for different Session classes
def session_class
SessionHash
end
# All thread safety and session retrieval procedures should occur here.
# Should return [session_id, session].
# If nil is provided as the session id, generation of a new valid id
# should occur within.
def find_session(env, sid)
raise '#find_session not implemented.'
end
# All thread safety and session storage procedures should occur here.
# Must return the session id if the session was saved successfully, or
# false if the session could not be saved.
def write_session(req, sid, session, options)
raise '#write_session not implemented.'
end
# All thread safety and session destroy procedures should occur here.
# Should return a new session id or nil if options[:drop]
def delete_session(req, sid, options)
raise '#delete_session not implemented'
end
end
class ID < Persisted
def self.inherited(klass)
k = klass.ancestors.find { |kl| kl.respond_to?(:superclass) && kl.superclass == ID }
unless k.instance_variable_defined?(:"@_rack_warned")
warn "#{klass} is inheriting from #{ID}. Inheriting from #{ID} is deprecated, please inherit from #{Persisted} instead" if $VERBOSE
k.instance_variable_set(:"@_rack_warned", true)
end
super
end
# All thread safety and session retrieval procedures should occur here.
# Should return [session_id, session].
# If nil is provided as the session id, generation of a new valid id
# should occur within.
def find_session(req, sid)
get_session req.env, sid
end
# All thread safety and session storage procedures should occur here.
# Must return the session id if the session was saved successfully, or
# false if the session could not be saved.
def write_session(req, sid, session, options)
set_session req.env, sid, session, options
end
# All thread safety and session destroy procedures should occur here.
# Should return a new session id or nil if options[:drop]
def delete_session(req, sid, options)
destroy_session req.env, sid, options
end
end
end
end
end