lib/omniauth/strategy.rb
require 'omniauth/key_store'
module OmniAuth
class NoSessionError < StandardError; end
# The Strategy is the base unit of OmniAuth's ability to
# wrangle multiple providers. Each strategy provided by
# OmniAuth includes this mixin to gain the default functionality
# necessary to be compatible with the OmniAuth library.
module Strategy # rubocop:disable ModuleLength
def self.included(base)
OmniAuth.strategies << base
base.extend ClassMethods
base.class_eval do
option :setup, false
option :skip_info, false
option :origin_param, 'origin'
end
end
module ClassMethods
# Returns an inherited set of default options set at the class-level
# for each strategy.
def default_options
# existing = superclass.default_options if superclass.respond_to?(:default_options)
existing = superclass.respond_to?(:default_options) ? superclass.default_options : {}
@default_options ||= OmniAuth::Strategy::Options.new(existing)
end
# This allows for more declarative subclassing of strategies by allowing
# default options to be set using a simple configure call.
#
# @param options [Hash] If supplied, these will be the default options (deep-merged into the superclass's default options).
# @yield [Options] The options Mash that allows you to set your defaults as you'd like.
#
# @example Using a yield to configure the default options.
#
# class MyStrategy
# include OmniAuth::Strategy
#
# configure do |c|
# c.foo = 'bar'
# end
# end
#
# @example Using a hash to configure the default options.
#
# class MyStrategy
# include OmniAuth::Strategy
# configure foo: 'bar'
# end
def configure(options = nil)
if block_given?
yield default_options
else
default_options.deep_merge!(options)
end
end
# Directly declare a default option for your class. This is a useful from
# a documentation perspective as it provides a simple line-by-line analysis
# of the kinds of options your strategy provides by default.
#
# @param name [Symbol] The key of the default option in your configuration hash.
# @param value [Object] The value your object defaults to. Nil if not provided.
#
# @example
#
# class MyStrategy
# include OmniAuth::Strategy
#
# option :foo, 'bar'
# option
# end
def option(name, value = nil)
default_options[name] = value
end
# Sets (and retrieves) option key names for initializer arguments to be
# recorded as. This takes care of 90% of the use cases for overriding
# the initializer in OmniAuth Strategies.
def args(args = nil)
if args
@args = Array(args)
return
end
existing = superclass.respond_to?(:args) ? superclass.args : []
(instance_variable_defined?(:@args) && @args) || existing
end
%w[uid info extra credentials].each do |fetcher|
class_eval <<-RUBY, __FILE__, __LINE__ + 1
attr_reader :#{fetcher}_proc
private :#{fetcher}_proc
def #{fetcher}(&block)
return #{fetcher}_proc unless block_given?
@#{fetcher}_proc = block
end
def #{fetcher}_stack(context)
compile_stack(self.ancestors, :#{fetcher}, context)
end
RUBY
end
def compile_stack(ancestors, method, context)
stack = ancestors.inject([]) do |a, ancestor|
a << context.instance_eval(&ancestor.send(method)) if ancestor.respond_to?(method) && ancestor.send(method)
a
end
stack.reverse!
end
end
attr_reader :app, :env, :options, :response
# Initializes the strategy by passing in the Rack endpoint,
# the unique URL segment name for this strategy, and any
# additional arguments. An `options` hash is automatically
# created from the last argument if it is a hash.
#
# @param app [Rack application] The application on which this middleware is applied.
#
# @overload new(app, options = {})
# If nothing but a hash is supplied, initialized with the supplied options
# overriding the strategy's default options via a deep merge.
# @overload new(app, *args, options = {})
# If the strategy has supplied custom arguments that it accepts, they may
# will be passed through and set to the appropriate values.
#
# @yield [Options] Yields options to block for further configuration.
def initialize(app, *args, &block) # rubocop:disable UnusedMethodArgument
@app = app
@env = nil
@options = self.class.default_options.dup
options.deep_merge!(args.pop) if args.last.is_a?(Hash)
options[:name] ||= self.class.to_s.split('::').last.downcase
self.class.args.each do |arg|
break if args.empty?
options[arg] = args.shift
end
# Make sure that all of the args have been dealt with, otherwise error out.
raise(ArgumentError.new("Received wrong number of arguments. #{args.inspect}")) unless args.empty?
yield options if block_given?
end
def inspect
"#<#{self.class}>"
end
# Direct access to the OmniAuth logger, automatically prefixed
# with this strategy's name.
#
# @example
# log :warn, "This is a warning."
def log(level, message)
OmniAuth.logger.send(level, "(#{name}) #{message}")
end
# Duplicates this instance and runs #call! on it.
# @param [Hash] The Rack environment.
def call(env)
dup.call!(env)
end
# The logic for dispatching any additional actions that need
# to be taken. For instance, calling the request phase if
# the request path is recognized.
#
# @param env [Hash] The Rack environment.
def call!(env) # rubocop:disable CyclomaticComplexity, PerceivedComplexity
unless env['rack.session']
error = OmniAuth::NoSessionError.new('You must provide a session to use OmniAuth.')
raise(error)
end
@env = env
warn_if_using_get_on_request_path
@env['omniauth.strategy'] = self if on_auth_path?
return mock_call!(env) if OmniAuth.config.test_mode
begin
return options_call if on_auth_path? && options_request?
return request_call if on_request_path? && OmniAuth.config.allowed_request_methods.include?(request.request_method.downcase.to_sym)
return callback_call if on_callback_path?
return other_phase if respond_to?(:other_phase)
rescue StandardError => e
raise e if env.delete('omniauth.error.app')
return fail!(e.message, e)
end
@app.call(env)
end
def warn_if_using_get_on_request_path
return unless on_request_path?
return unless OmniAuth.config.allowed_request_methods.include?(:get)
return if OmniAuth.config.silence_get_warning
log :warn, <<-WARN
You are using GET as an allowed request method for OmniAuth. This may leave
you open to CSRF attacks. As of v2.0.0, OmniAuth by default allows only POST
to its own routes. You should review the following resources to guide your
mitigation:
https://github.com/omniauth/omniauth/wiki/Resolving-CVE-2015-9284
https://github.com/omniauth/omniauth/issues/960
https://nvd.nist.gov/vuln/detail/CVE-2015-9284
https://github.com/omniauth/omniauth/pull/809
You can ignore this warning by setting:
OmniAuth.config.silence_get_warning = true
WARN
end
# Responds to an OPTIONS request.
def options_call
OmniAuth.config.before_options_phase.call(env) if OmniAuth.config.before_options_phase
verbs = OmniAuth.config.allowed_request_methods.collect(&:to_s).collect(&:upcase).join(', ')
[200, {'Allow' => verbs}, []]
end
# Performs the steps necessary to run the request phase of a strategy.
def request_call # rubocop:disable CyclomaticComplexity, MethodLength, PerceivedComplexity
setup_phase
log :debug, 'Request phase initiated.'
# store query params from the request url, extracted in the callback_phase
session['omniauth.params'] = request.GET
OmniAuth.config.request_validation_phase.call(env) if OmniAuth.config.request_validation_phase
OmniAuth.config.before_request_phase.call(env) if OmniAuth.config.before_request_phase
if options.form.respond_to?(:call)
log :debug, 'Rendering form from supplied Rack endpoint.'
options.form.call(env)
elsif options.form
log :debug, 'Rendering form from underlying application.'
call_app!
elsif !options.origin_param
request_phase
else
if request.params[options.origin_param]
env['rack.session']['omniauth.origin'] = request.params[options.origin_param]
elsif env['HTTP_REFERER'] && !env['HTTP_REFERER'].match(/#{request_path}$/)
env['rack.session']['omniauth.origin'] = env['HTTP_REFERER']
end
request_phase
end
rescue OmniAuth::AuthenticityError => e
fail!(:authenticity_error, e)
end
# Performs the steps necessary to run the callback phase of a strategy.
def callback_call
setup_phase
log :debug, 'Callback phase initiated.'
@env['omniauth.origin'] = session.delete('omniauth.origin')
@env['omniauth.origin'] = nil if env['omniauth.origin'] == ''
@env['omniauth.params'] = session.delete('omniauth.params') || {}
OmniAuth.config.before_callback_phase.call(@env) if OmniAuth.config.before_callback_phase
callback_phase
end
# Returns true if the environment recognizes either the
# request or callback path.
def on_auth_path?
on_request_path? || on_callback_path?
end
def on_request_path?
if options[:request_path].respond_to?(:call)
options[:request_path].call(env)
else
on_path?(request_path)
end
end
def on_callback_path?
on_path?(callback_path)
end
def on_path?(path)
current_path.casecmp(path).zero?
end
def options_request?
request.request_method == 'OPTIONS'
end
# This is called in lieu of the normal request process
# in the event that OmniAuth has been configured to be
# in test mode.
def mock_call!(*)
begin
return mock_request_call if on_request_path? && OmniAuth.config.allowed_request_methods.include?(request.request_method.downcase.to_sym)
return mock_callback_call if on_callback_path?
rescue StandardError => e
raise e if env.delete('omniauth.error.app')
return fail!(e.message, e)
end
call_app!
end
def mock_request_call
setup_phase
session['omniauth.params'] = request.GET
OmniAuth.config.request_validation_phase.call(env) if OmniAuth.config.request_validation_phase
OmniAuth.config.before_request_phase.call(env) if OmniAuth.config.before_request_phase
if options.origin_param
if request.params[options.origin_param]
session['omniauth.origin'] = request.params[options.origin_param]
elsif env['HTTP_REFERER'] && !env['HTTP_REFERER'].match(/#{request_path}$/)
session['omniauth.origin'] = env['HTTP_REFERER']
end
end
redirect(callback_url)
end
def mock_callback_call
setup_phase
@env['omniauth.origin'] = session.delete('omniauth.origin')
@env['omniauth.origin'] = nil if env['omniauth.origin'] == ''
@env['omniauth.params'] = session.delete('omniauth.params') || {}
mocked_auth = OmniAuth.mock_auth_for(name.to_s)
if mocked_auth.is_a?(Symbol)
fail!(mocked_auth)
else
@env['omniauth.auth'] = mocked_auth
OmniAuth.config.before_callback_phase.call(@env) if OmniAuth.config.before_callback_phase
call_app!
end
end
# The setup phase looks for the `:setup` option to exist and,
# if it is, will call either the Rack endpoint supplied to the
# `:setup` option or it will call out to the setup path of the
# underlying application. This will default to `/auth/:provider/setup`.
def setup_phase
if options[:setup].respond_to?(:call)
log :debug, 'Setup endpoint detected, running now.'
options[:setup].call(env)
elsif options[:setup]
log :debug, 'Calling through to underlying application for setup.'
setup_env = env.merge('PATH_INFO' => setup_path, 'REQUEST_METHOD' => 'GET')
call_app!(setup_env)
end
end
# @abstract This method is called when the user is on the request path. You should
# perform any information gathering you need to be able to authenticate
# the user in this phase.
def request_phase
raise(NotImplementedError)
end
def uid
self.class.uid_stack(self).last
end
def info
merge_stack(self.class.info_stack(self))
end
def credentials
merge_stack(self.class.credentials_stack(self))
end
def extra
merge_stack(self.class.extra_stack(self))
end
def auth_hash
credentials_data = credentials
extra_data = extra
AuthHash.new(:provider => name, :uid => uid).tap do |auth|
auth.info = info unless skip_info?
auth.credentials = credentials_data if credentials_data
auth.extra = extra_data if extra_data
end
end
# Determines whether or not user info should be retrieved. This
# allows some strategies to save a call to an external API service
# for existing users. You can use it either by setting the `:skip_info`
# to true or by setting `:skip_info` to a Proc that takes a uid and
# evaluates to true when you would like to skip info.
#
# @example
#
# use MyStrategy, :skip_info => lambda{|uid| User.find_by_uid(uid)}
def skip_info?
return false unless options.skip_info?
return true unless options.skip_info.respond_to?(:call)
options.skip_info.call(uid)
end
def callback_phase
env['omniauth.auth'] = auth_hash
call_app!
end
def path_prefix
options[:path_prefix] || OmniAuth.config.path_prefix
end
def custom_path(kind)
if options[kind].respond_to?(:call)
result = options[kind].call(env)
return nil unless result.is_a?(String)
result
else
options[kind]
end
end
def request_path
@request_path ||=
if options[:request_path].is_a?(String)
options[:request_path]
else
"#{script_name}#{path_prefix}/#{name}"
end
end
def callback_path
@callback_path ||= begin
path = options[:callback_path] if options[:callback_path].is_a?(String)
path ||= current_path if options[:callback_path].respond_to?(:call) && options[:callback_path].call(env)
path ||= custom_path(:request_path)
path ||= "#{script_name}#{path_prefix}/#{name}/callback"
path
end
end
def setup_path
options[:setup_path] || "#{path_prefix}/#{name}/setup"
end
CURRENT_PATH_REGEX = %r{/$}.freeze
EMPTY_STRING = ''.freeze
def current_path
@current_path ||= request.path.downcase.sub(CURRENT_PATH_REGEX, EMPTY_STRING)
end
def query_string
request.query_string.empty? ? '' : "?#{request.query_string}"
end
def call_app!(env = @env)
@app.call(env)
rescue StandardError => e
env['omniauth.error.app'] = true
raise e
end
def full_host
case OmniAuth.config.full_host
when String
OmniAuth.config.full_host
when Proc
OmniAuth.config.full_host.call(env)
else
# in Rack 1.3.x, request.url explodes if scheme is nil
if request.scheme && request.url.match(URI::ABS_URI)
uri = URI.parse(request.url.gsub(/\?.*$/, ''))
uri.path = ''
# sometimes the url is actually showing http inside rails because the
# other layers (like nginx) have handled the ssl termination.
uri.scheme = 'https' if ssl? # rubocop:disable BlockNesting
uri.to_s
else ''
end
end
end
def callback_url
full_host + callback_path + query_string
end
def script_name
return '' if @env.nil?
@env['SCRIPT_NAME'] || ''
end
def session
@env['rack.session']
end
def request
@request ||= Rack::Request.new(@env)
end
def name
options[:name]
end
def redirect(uri)
r = Rack::Response.new
if options[:iframe]
r.write("<script type='text/javascript' charset='utf-8'>top.location.href = '#{uri}';</script>")
else
r.write("Redirecting to #{uri}...")
r.redirect(uri)
end
r.finish
end
def user_info
{}
end
def fail!(message_key, exception = nil)
env['omniauth.error'] = exception
env['omniauth.error.type'] = message_key.to_sym
env['omniauth.error.strategy'] = self
if exception
log :error, "Authentication failure! #{message_key}: #{exception.class}, #{exception.message}"
else
log :error, "Authentication failure! #{message_key} encountered."
end
OmniAuth.config.on_failure.call(env)
end
class Options < OmniAuth::KeyStore; end
protected
def initialize_copy(*args)
super
@options = @options.dup
end
def merge_stack(stack)
stack.inject({}) do |a, e|
a.merge!(e)
a
end
end
def ssl?
request.env['HTTPS'] == 'on' ||
request.env['HTTP_X_FORWARDED_SSL'] == 'on' ||
request.env['HTTP_X_FORWARDED_SCHEME'] == 'https' ||
(request.env['HTTP_X_FORWARDED_PROTO'] && request.env['HTTP_X_FORWARDED_PROTO'].split(',')[0] == 'https') ||
request.env['rack.url_scheme'] == 'https'
end
end
end