# AUTHOR: blink <blinketje@gmail.com>; blink#ruby-lang@irc.freenode.net
gem 'ruby-openid', '~> 2' if defined? Gem
require 'rack/request'
require 'rack/utils'
require 'rack/auth/abstract/handler'
require 'uri'
require 'openid' #gem
require 'openid/extension' #gem
require 'openid/store/memory' #gem
module Rack
class Request
def openid_request
@env['rack.auth.openid.request']
end
def openid_response
@env['rack.auth.openid.response']
end
end
module Auth
# Rack::Auth::OpenID provides a simple method for setting up an OpenID
# Consumer. It requires the ruby-openid library from janrain to operate,
# as well as a rack method of session management.
#
# The ruby-openid home page is at http://openidenabled.com/ruby-openid/.
#
# The OpenID specifications can be found at
# http://openid.net/specs/openid-authentication-1_1.html
# and
# http://openid.net/specs/openid-authentication-2_0.html. Documentation
# for published OpenID extensions and related topics can be found at
# http://openid.net/developers/specs/.
#
# It is recommended to read through the OpenID spec, as well as
# ruby-openid's documentation, to understand what exactly goes on. However
# a setup as simple as the presented examples is enough to provide
# Consumer functionality.
#
# This library strongly intends to utilize the OpenID 2.0 features of the
# ruby-openid library, which provides OpenID 1.0 compatiblity.
#
# NOTE: Due to the amount of data that this library stores in the
# session, Rack::Session::Cookie may fault.
class OpenID
class NoSession < RuntimeError; end
class BadExtension < RuntimeError; end
# Required for ruby-openid
ValidStatus = [:success, :setup_needed, :cancel, :failure]
# = Arguments
#
# The first argument is the realm, identifying the site they are trusting
# with their identity. This is required, also treated as the trust_root
# in OpenID 1.x exchanges.
#
# The optional second argument is a hash of options.
#
# == Options
#
# <tt>:return_to</tt> defines the url to return to after the client
# authenticates with the openid service provider. This url should point
# to where Rack::Auth::OpenID is mounted. If <tt>:return_to</tt> is not
# provided, return_to will be the current url which allows flexibility
# with caveats.
#
# <tt>:session_key</tt> defines the key to the session hash in the env.
# It defaults to 'rack.session'.
#
# <tt>:openid_param</tt> defines at what key in the request parameters to
# find the identifier to resolve. As per the 2.0 spec, the default is
# 'openid_identifier'.
#
# <tt>:store</tt> defined what OpenID Store to use for persistant
# information. By default a Store::Memory will be used.
#
# <tt>:immediate</tt> as true will make initial requests to be of an
# immediate type. This is false by default. See OpenID specification
# documentation.
#
# <tt>:extensions</tt> should be a hash of openid extension
# implementations. The key should be the extension main module, the value
# should be an array of arguments for extension::Request.new.
# The hash is iterated over and passed to #add_extension for processing.
# Please see #add_extension for further documentation.
#
# == Examples
#
# simple_oid = OpenID.new('http://mysite.com/')
#
# return_oid = OpenID.new('http://mysite.com/', {
# :return_to => 'http://mysite.com/openid'
# })
#
# complex_oid = OpenID.new('http://mysite.com/',
# :immediate => true,
# :extensions => {
# ::OpenID::SReg => [['email'],['nickname']]
# }
# )
#
# = Advanced
#
# Most of the functionality of this library is encapsulated such that
# expansion and overriding functions isn't difficult nor tricky.
# Alternately, to avoid opening up singleton objects or subclassing, a
# wrapper rack middleware can be composed to act upon Auth::OpenID's
# responses. See #check and #finish for locations of pertinent data.
#
# == Responses
#
# To change the responses that Auth::OpenID returns, override the methods
# #redirect, #bad_request, #unauthorized, #access_denied, and
# #foreign_server_failure.
#
# Additionally #confirm_post_params is used when the URI would exceed
# length limits on a GET request when doing the initial verification
# request.
#
# == Processing
#
# To change methods of processing completed transactions, override the
# methods #success, #setup_needed, #cancel, and #failure. Please ensure
# the returned object is a rack compatible response.
#
# The first argument is an OpenID::Response, the second is a
# Rack::Request of the current request, the last is the hash used in
# ruby-openid handling, which can be found manually at
# env['rack.session'][:openid].
#
# This is useful if you wanted to expand the processing done, such as
# setting up user accounts.
#
# oid_app = Rack::Auth::OpenID.new realm, :return_to => return_to
# def oid_app.success oid, request, session
# user = Models::User[oid.identity_url]
# user ||= Models::User.create_from_openid oid
# request['rack.session'][:user] = user.id
# redirect MyApp.site_home
# end
#
# site_map['/openid'] = oid_app
# map = Rack::URLMap.new site_map
# ...
def initialize(realm, options={})
realm = URI(realm)
raise ArgumentError, "Invalid realm: #{realm}" \
unless realm.absolute? \
and realm.fragment.nil? \
and realm.scheme =~ /^https?$/ \
and realm.host =~ /^(\*\.)?#{URI::REGEXP::PATTERN::URIC_NO_SLASH}+/
realm.path = '/' if realm.path.empty?
@realm = realm.to_s
if ruri = options[:return_to]
ruri = URI(ruri)
raise ArgumentError, "Invalid return_to: #{ruri}" \
unless ruri.absolute? \
and ruri.scheme =~ /^https?$/ \
and ruri.fragment.nil?
raise ArgumentError, "return_to #{ruri} not within realm #{realm}" \
unless self.within_realm?(ruri)
@return_to = ruri.to_s
end
@session_key = options[:session_key] || 'rack.session'
@openid_param = options[:openid_param] || 'openid_identifier'
@store = options[:store] || ::OpenID::Store::Memory.new
@immediate = !!options[:immediate]
@extensions = {}
if extensions = options.delete(:extensions)
extensions.each do |ext, args|
add_extension ext, *args
end
end
# Undocumented, semi-experimental
@anonymous = !!options[:anonymous]
end
attr_reader :realm, :return_to, :session_key, :openid_param, :store,
:immediate, :extensions
# Sets up and uses session data at <tt>:openid</tt> within the session.
# Errors in this setup will raise a NoSession exception.
#
# If the parameter 'openid.mode' is set, which implies a followup from
# the openid server, processing is passed to #finish and the result is
# returned. However, if there is no appropriate openid information in the
# session, a 400 error is returned.
#
# If the parameter specified by <tt>options[:openid_param]</tt> is
# present, processing is passed to #check and the result is returned.
#
# If neither of these conditions are met, #unauthorized is called.
def call(env)
env['rack.auth.openid'] = self
env_session = env[@session_key]
unless env_session and env_session.is_a?(Hash)
raise NoSession, 'No compatible session'
end
# let us work in our own namespace...
session = (env_session[:openid] ||= {})
unless session and session.is_a?(Hash)
raise NoSession, 'Incompatible openid session'
end
request = Rack::Request.new(env)
consumer = ::OpenID::Consumer.new(session, @store)
if mode = request.GET['openid.mode']
if session.key?(:openid_param)
finish(consumer, session, request)
else
bad_request
end
elsif request.GET[@openid_param]
check(consumer, session, request)
else
unauthorized
end
end
# As the first part of OpenID consumer action, #check retrieves the data
# required for completion.
#
# If all parameters fit within the max length of a URI, a 303 redirect
# will be returned. Otherwise #confirm_post_params will be called.
#
# Any messages from OpenID's request are logged to env['rack.errors']
#
# <tt>env['rack.auth.openid.request']</tt> is the openid checkid request
# instance.
#
# <tt>session[:openid_param]</tt> is set to the openid identifier
# provided by the user.
#
# <tt>session[:return_to]</tt> is set to the return_to uri given to the
# identity provider.
def check(consumer, session, req)
oid = consumer.begin(req.GET[@openid_param], @anonymous)
req.env['rack.auth.openid.request'] = oid
req.env['rack.errors'].puts(oid.message)
p oid if $DEBUG
## Extension support
extensions.each do |ext,args|
oid.add_extension(ext::Request.new(*args))
end
session[:openid_param] = req.GET[openid_param]
return_to_uri = return_to ? return_to : req.url
session[:return_to] = return_to_uri
immediate = session.key?(:setup_needed) ? false : immediate
if oid.send_redirect?(realm, return_to_uri, immediate)
uri = oid.redirect_url(realm, return_to_uri, immediate)
redirect(uri)
else
confirm_post_params(oid, realm, return_to_uri, immediate)
end
rescue ::OpenID::DiscoveryFailure => e
# thrown from inside OpenID::Consumer#begin by yadis stuff
req.env['rack.errors'].puts([e.message, *e.backtrace]*"\n")
return foreign_server_failure
end
# This is the final portion of authentication.
# If successful, a redirect to the realm is be returned.
# Data gathered from extensions are stored in session[:openid] with the
# extension's namespace uri as the key.
#
# Any messages from OpenID's response are logged to env['rack.errors']
#
# <tt>env['rack.auth.openid.response']</tt> will contain the openid
# response.
def finish(consumer, session, req)
oid = consumer.complete(req.GET, req.url)
req.env['rack.auth.openid.response'] = oid
req.env['rack.errors'].puts(oid.message)
p oid if $DEBUG
raise unless ValidStatus.include?(oid.status)
__send__(oid.status, oid, req, session)
end
# The first argument should be the main extension module.
# The extension module should contain the constants:
# * class Request, should have OpenID::Extension as an ancestor
# * class Response, should have OpenID::Extension as an ancestor
# * string NS_URI, which defining the namespace of the extension
#
# All trailing arguments will be passed to extension::Request.new in
# #check.
# The openid response will be passed to
# extension::Response#from_success_response, #get_extension_args will be
# called on the result to attain the gathered data.
#
# This method returns the key at which the response data will be found in
# the session, which is the namespace uri by default.
def add_extension(ext, *args)
raise BadExtension unless valid_extension?(ext)
extensions[ext] = args
return ext::NS_URI
end
# Checks the validitity, in the context of usage, of a submitted
# extension.
def valid_extension?(ext)
if not %w[NS_URI Request Response].all?{|c| ext.const_defined?(c) }
raise ArgumentError, 'Extension is missing constants.'
elsif not ext::Response.respond_to?(:from_success_response)
raise ArgumentError, 'Response is missing required method.'
end
return true
rescue
return false
end
# Checks the provided uri to ensure it'd be considered within the realm.
# is currently not compatible with wildcard realms.
def within_realm? uri
uri = URI.parse(uri.to_s)
realm = URI.parse(self.realm)
return false unless uri.absolute?
return false unless uri.path[0, realm.path.size] == realm.path
return false unless uri.host == realm.host or realm.host[/^\*\./]
# for wildcard support, is awkward with URI limitations
realm_match = Regexp.escape(realm.host).
sub(/^\*\./,"^#{URI::REGEXP::PATTERN::URIC_NO_SLASH}+.")+'$'
return false unless uri.host.match(realm_match)
return true
end
alias_method :include?, :within_realm?
protected
### These methods define some of the boilerplate responses.
# Returns an html form page for posting to an Identity Provider if the
# GET request would exceed the upper URI length limit.
def confirm_post_params(oid, realm, return_to, immediate)
Rack::Response.new.finish do |r|
r.write '<html><head><title>Confirm...</title></head><body>'
r.write oid.form_markup(realm, return_to, immediate)
r.write '</body></html>'
end
end
# Returns a 303 redirect with the destination of that provided by the
# argument.
def redirect(uri)
[ 303, {'Content-Length'=>'0', 'Content-Type'=>'text/plain',
'Location' => uri},
[] ]
end
# Returns an empty 400 response.
def bad_request
[ 400, {'Content-Type'=>'text/plain', 'Content-Length'=>'0'},
[''] ]
end
# Returns a basic unauthorized 401 response.
def unauthorized
[ 401, {'Content-Type' => 'text/plain', 'Content-Length' => '13'},
['Unauthorized.'] ]
end
# Returns a basic access denied 403 response.
def access_denied
[ 403, {'Content-Type' => 'text/plain', 'Content-Length' => '14'},
['Access denied.'] ]
end
# Returns a 503 response to be used if communication with the remote
# OpenID server fails.
def foreign_server_failure
[ 503, {'Content-Type'=>'text/plain', 'Content-Length' => '23'},
['Foreign server failure.'] ]
end
private
### These methods are called after a transaction is completed, depending
# on its outcome. These should all return a rack compatible response.
# You'd want to override these to provide additional functionality.
# Called to complete processing on a successful transaction.
# Within the openid session, :openid_identity and :openid_identifier are
# set to the user friendly and the standard representation of the
# validated identity. All other data in the openid session is cleared.
def success(oid, request, session)
session.clear
session[:openid_identity] = oid.display_identifier
session[:openid_identifier] = oid.identity_url
extensions.keys.each do |ext|
label = ext.name[/[^:]+$/].downcase
response = ext::Response.from_success_response(oid)
session[label] = response.data
end
redirect(realm)
end
# Called if the Identity Provider indicates further setup by the user is
# required.
# The identifier is retrived from the openid session at :openid_param.
# And :setup_needed is set to true to prevent looping.
def setup_needed(oid, request, session)
identifier = session[:openid_param]
session[:setup_needed] = true
redirect req.script_name + '?' + openid_param + '=' + identifier
end
# Called if the user indicates they wish to cancel identification.
# Data within openid session is cleared.
def cancel(oid, request, session)
session.clear
access_denied
end
# Called if the Identity Provider indicates the user is unable to confirm
# their identity. Data within the openid session is left alone, in case
# of swarm auth attacks.
def failure(oid, request, session)
unauthorized
end
end
# A class developed out of the request to use OpenID as an authentication
# middleware. The request will be sent to the OpenID instance unless the
# block evaluates to true. For example in rackup, you can use it as such:
#
# use Rack::Session::Pool
# use Rack::Auth::OpenIDAuth, realm, openid_options do |env|
# env['rack.session'][:authkey] == a_string
# end
# run RackApp
#
# Or simply:
#
# app = Rack::Auth::OpenIDAuth.new app, realm, openid_options, &auth
class OpenIDAuth < Rack::Auth::AbstractHandler
attr_reader :oid
def initialize(app, realm, options={}, &auth)
@oid = OpenID.new(realm, options)
super(app, &auth)
end
def call(env)
to = auth.call(env) ? @app : @oid
to.call env
end
end
end
end