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require 'casclient'
module RubyCAS
class Railtie < Rails::Railtie
config.rubycas = ActiveSupport::OrderedOptions.new
initializer 'rubycas.initialize' do |app|
RubyCAS::Filter.setup(config.rubycas)
end
end
class Filter
cattr_reader :config, :log, :client
# These are initialized when you call setup.
@@client = nil
@@log = nil
@@fake_user = nil
@@fake_extra_attributes = nil
class << self
def setup(config)
@@config = config
@@config[:logger] = Rails.logger unless @@config[:logger]
@@client = CASClient::Client.new(@@config)
@@log = @@client.log
end
def filter(controller)
raise "Cannot use the CASClient filter because it has not yet been configured." if config.nil?
if @@fake_user
controller.session[client.username_session_key] = @@fake_user
controller.session[:casfilteruser] = @@fake_user
controller.session[client.extra_attributes_session_key] = @@fake_extra_attributes
return true
end
### patch this line to recreate the 2 items from cookie
last_st = controller.session[:cas_last_valid_ticket]
last_st_service = controller.session[:cas_last_valid_ticket_service]
if single_sign_out(controller)
controller.send(:render, :text => "CAS Single-Sign-Out request intercepted.")
return false
end
st = read_ticket(controller)
# is_new_session = true
if st && last_st &&
last_st == st.ticket &&
last_st_service == st.service
# warn() rather than info() because we really shouldn't be re-validating the same ticket.
# The only situation where this is acceptable is if the user manually does a refresh and
# the same ticket happens to be in the URL.
log.warn("Re-using previously validated ticket since the ticket id and service are the same.")
#st = last_st
return true
elsif last_st &&
!config[:authenticate_on_every_request] &&
controller.session[client.username_session_key]
# Re-use the previous ticket if the user already has a local CAS session (i.e. if they were already
# previously authenticated for this service). This is to prevent redirection to the CAS server on every
# request.
#
# This behaviour can be disabled (so that every request is routed through the CAS server) by setting
# the :authenticate_on_every_request config option to true. However, this is not desirable since
# it will almost certainly break POST request, AJAX calls, etc.
log.debug "Existing local CAS session detected for #{controller.session[client.username_session_key].inspect}. "+
"Previous ticket #{last_st_service} will be re-used."
#st = last_st
return true
end
if st
client.validate_service_ticket(st) unless st.has_been_validated?
#vr = st.success
if st.is_valid?
#if is_new_session
log.info("Ticket #{st.ticket.inspect} for service #{st.service.inspect} belonging to user #{st.user.inspect} is VALID.")
controller.session[client.username_session_key] = st.user.dup
controller.session[client.extra_attributes_session_key] = HashWithIndifferentAccess.new(st.extra_attributes) if st.extra_attributes
if st.extra_attributes
log.debug("Extra user attributes provided along with ticket #{st.ticket.inspect}: #{st.extra_attributes.inspect}.")
end
# RubyCAS-Client 1.x used :casfilteruser as it's username session key,
# so we need to set this here to ensure compatibility with configurations
# built around the old client.
controller.session[:casfilteruser] = st.user
if config[:enable_single_sign_out]
f = store_service_session_lookup(st, controller.request.session_options[:id] || controller.session.session_id)
log.debug("Wrote service session lookup file to #{f.inspect} with session id #{controller.request.session_options[:id] || controller.session.session_id.inspect}.")
end
#end
# Store the ticket in the session to avoid re-validating the same service
# ticket with the CAS server.
controller.session[:cas_last_valid_ticket] = st.ticket
controller.session[:cas_last_valid_ticket_service] = st.service
if st.pgt_iou
unless controller.session[:cas_pgt] && controller.session[:cas_pgt].ticket && controller.session[:cas_pgt].iou == st.pgt_iou
log.info("Receipt has a proxy-granting ticket IOU. Attempting to retrieve the proxy-granting ticket...")
pgt = client.retrieve_proxy_granting_ticket(st.pgt_iou)
if pgt
log.debug("Got PGT #{pgt.ticket.inspect} for PGT IOU #{pgt.iou.inspect}. This will be stored in the session.")
controller.session[:cas_pgt] = pgt
# For backwards compatibility with RubyCAS-Client 1.x configurations...
controller.session[:casfilterpgt] = pgt
else
log.error("Failed to retrieve a PGT for PGT IOU #{st.pgt_iou}!")
end
else
log.info("PGT is present in session and PGT IOU #{st.pgt_iou} matches the saved PGT IOU. Not retrieving new PGT.")
end
end
return true
else
log.warn("Ticket #{st.ticket.inspect} failed validation -- #{st.failure_code}: #{st.failure_message}")
unauthorized!(controller, st)
return false
end
else # no service ticket was present in the request
if returning_from_gateway?(controller)
log.info "Returning from CAS gateway without authentication."
# unset, to allow for the next request to be authenticated if necessary
controller.session[:cas_sent_to_gateway] = false
if use_gatewaying?
log.info "This CAS client is configured to use gatewaying, so we will permit the user to continue without authentication."
controller.session[client.username_session_key] = nil
return true
else
log.warn "The CAS client is NOT configured to allow gatewaying, yet this request was gatewayed. Something is not right!"
end
end
unauthorized!(controller)
return false
end
rescue OpenSSL::SSL::SSLError => sslexception
log.error("SSL Error: #{sslexception}")
unauthorized!(controller)
return false
end
# used to allow faking for testing
# with cucumber and other tools.
# use like
# CASClient::Frameworks::Rails::Filter.fake("homer")
# you can also fake extra attributes by including a second parameter
# CASClient::Frameworks::Rails::Filter.fake("homer", {:roles => ['dad', 'husband']})
def fake(username, extra_attributes = nil)
@@fake_user = username
@@fake_extra_attributes = extra_attributes
end
def use_gatewaying?
@@config[:use_gatewaying]
end
# Returns the login URL for the current controller.
# Useful when you want to provide a "Login" link in a GatewayFilter'ed
# action.
def login_url(controller)
service_url = read_service_url(controller)
url = client.add_service_to_login_url(service_url)
log.debug("Generated login url: #{url}")
return url
end
# allow controllers to reuse the existing config to auto-login to
# the service
#
# Use this from within a controller. Pass the controller, the
# login-credentials and the path that you want the user
# resdirected to on success.
#
# When writing a login-action you must check the return-value of
# the response to see if it failed!
#
# If it worked - you need to redirect the user to the service -
# path, because that has the ticket that will *actually* log them
# into your system
#
# example:
# def autologin
# resp = CASClient::Frameworks::Rails::Filter.login_to_service(self, credentials, dashboard_url)
# if resp.is_faiulure?
# flash[:error] = 'Login failed'
# render :action => 'login'
# else
# return redirect_to(@resp.service_redirect_url)
# end
# end
def login_to_service(controller, credentials, return_path)
resp = @@client.login_to_service(credentials, return_path)
if resp.is_failure?
log.info("Validation failed for service #{return_path.inspect} reason: '#{resp.failure_message}'")
else
log.info("Ticket #{resp.ticket.inspect} for service #{return_path.inspect} is VALID.")
end
resp
end
# Clears the given controller's local Rails session, does some local
# CAS cleanup, and redirects to the CAS logout page. Additionally, the
# <tt>request.referer</tt> value from the <tt>controller</tt> instance
# is passed to the CAS server as a 'destination' parameter. This
# allows RubyCAS server to provide a follow-up login page allowing
# the user to log back in to the service they just logged out from
# using a different username and password. Other CAS server
# implemenations may use this 'destination' parameter in different
# ways.
# If given, the optional <tt>service</tt> URL overrides
# <tt>request.referer</tt>.
def logout(controller, service = nil)
referer = service || controller.request.referer
st = controller.session[:cas_last_valid_ticket]
delete_service_session_lookup(st) if st
controller.send(:reset_session)
controller.send(:redirect_to, client.logout_url(referer))
end
def unauthorized!(controller, vr = nil)
if controller.params[:format] == "xml"
if vr
controller.send(:render, :xml => "<errors><error>#{vr.failure_message}</error></errors>", :status => 401)
else
controller.send(:head, 401)
end
else
redirect_to_cas_for_authentication(controller)
end
end
def redirect_to_cas_for_authentication(controller)
redirect_url = login_url(controller)
if use_gatewaying?
controller.session[:cas_sent_to_gateway] = true
redirect_url << "&gateway=true"
else
controller.session[:cas_sent_to_gateway] = false
end
if controller.session[:previous_redirect_to_cas] &&
controller.session[:previous_redirect_to_cas] > (Time.now - 1.second)
log.warn("Previous redirect to the CAS server was less than a second ago. The client at #{controller.request.remote_ip.inspect} may be stuck in a redirection loop!")
controller.session[:cas_validation_retry_count] ||= 0
if controller.session[:cas_validation_retry_count] > 3
log.error("Redirection loop intercepted. Client at #{controller.request.remote_ip.inspect} will be redirected back to login page and forced to renew authentication.")
redirect_url += "&renew=1&redirection_loop_intercepted=1"
end
controller.session[:cas_validation_retry_count] += 1
else
controller.session[:cas_validation_retry_count] = 0
end
controller.session[:previous_redirect_to_cas] = Time.now
log.debug("Redirecting to #{redirect_url.inspect}")
controller.send(:redirect_to, redirect_url)
end
private
def single_sign_out(controller)
# Avoid calling raw_post (which may consume the post body) if
# this seems to be a file upload
if content_type = controller.request.headers["CONTENT_TYPE"] &&
content_type =~ %r{^multipart/}
return false
end
if controller.request.post? &&
controller.params['logoutRequest'] &&
URI.unescape(controller.params['logoutRequest']) =~
%r{^<samlp:LogoutRequest.*?<samlp:SessionIndex>(.*)</samlp:SessionIndex>}m
# TODO: Maybe check that the request came from the registered CAS server? Although this might be
# pointless since it's easily spoofable...
si = $~[1]
unless config[:enable_single_sign_out]
log.warn "Ignoring single-sign-out request for CAS session #{si.inspect} because ssout functionality is not enabled (see the :enable_single_sign_out config option)."
return false
end
log.debug "Intercepted single-sign-out request for CAS session #{si.inspect}."
# Rails 2.3
##required_sess_store = ActiveRecord::SessionStore
##current_sess_store = ActionController::Base.session_store
# Rails 2.2
## required_sess_store = CGI::Session::ActiveRecordStore
## current_sess_store = ActionController::Base.session_options[:database_manager]
# Rails 3.0
required_sess_store = ActiveRecord::SessionStore
current_sess_store = ::Rails.application.config.session_store
if current_sess_store == required_sess_store
session_id = read_service_session_lookup(si)
if session_id
session = current_sess_store::Session.find_by_session_id(session_id)
if session
st = session.data[:cas_last_valid_ticket] || si
delete_service_session_lookup(st) if st
session.destroy
log.debug("Destroyed #{session.inspect} for session #{session_id.inspect} corresponding to service ticket #{si.inspect}.")
else
log.debug("Data for session #{session_id.inspect} was not found. It may have already been cleared by a local CAS logout request.")
end
log.info("Single-sign-out for session #{session_id.inspect} completed successfuly.")
else
log.warn("Couldn't destroy session with SessionIndex #{si} because no corresponding session id could be looked up.")
end
else
log.error "Cannot process logout request because this Rails application's session store is "+
" #{current_sess_store.name.inspect}. Single Sign-Out only works with the "+
" #{required_sess_store.name.inspect} session store."
end
# Return true to indicate that a single-sign-out request was detected
# and that further processing of the request is unnecessary.
return true
end
# This is not a single-sign-out request.
return false
end
def read_ticket(controller)
# Note that we are now deleting the 'ticket' and 'renew' parameters, since they really
# have no business getting passed on to the controller action.
ticket = controller.params.delete(:ticket)
return nil unless ticket
log.debug("Request contains ticket #{ticket.inspect}.")
if ticket =~ /^PT-/
CASClient::ProxyTicket.new(ticket, read_service_url(controller), controller.params.delete(:renew))
else
CASClient::ServiceTicket.new(ticket, read_service_url(controller), controller.params.delete(:renew))
end
end
def returning_from_gateway?(controller)
controller.session[:cas_sent_to_gateway]
end
def read_service_url(controller)
if config[:service_url]
log.debug("Using explicitly set service url: #{config[:service_url]}")
return config[:service_url]
end
params = controller.params.dup
params.delete(:ticket)
service_url = controller.url_for(params)
log.debug("Guessed service url: #{service_url.inspect}")
return service_url
end
# Creates a file in tmp/sessions linking a SessionTicket
# with the local Rails session id. The file is named
# cas_sess.<session ticket> and its text contents is the corresponding
# Rails session id.
# Returns the filename of the lookup file created.
def store_service_session_lookup(st, sid)
st = st.ticket if st.kind_of? CASClient::ServiceTicket
f = File.new(filename_of_service_session_lookup(st), 'w')
f.write(sid)
f.close
return f.path
end
# Returns the local Rails session ID corresponding to the given
# ServiceTicket. This is done by reading the contents of the
# cas_sess.<session ticket> file created in a prior call to
# #store_service_session_lookup.
def read_service_session_lookup(st)
st = st.ticket if st.kind_of? CASClient::ServiceTicket
ssl_filename = filename_of_service_session_lookup(st)
return File.exists?(ssl_filename) && IO.read(ssl_filename)
end
# Removes a stored relationship between a ServiceTicket and a local
# Rails session id. This should be called when the session is being
# closed.
#
# See #store_service_session_lookup.
def delete_service_session_lookup(st)
st = st.ticket if st.kind_of? CASClient::ServiceTicket
ssl_filename = filename_of_service_session_lookup(st)
File.delete(ssl_filename) if File.exists?(ssl_filename)
end
# Returns the path and filename of the service session lookup file.
def filename_of_service_session_lookup(st)
st = st.ticket if st.kind_of? CASClient::ServiceTicket
return "#{Rails.root}/tmp/sessions/cas_sess.#{st}"
end
end
end
class GatewayFilter < Filter
def self.use_gatewaying?
return true unless @@config[:use_gatewaying] == false
end
end
end