class SingleSignOn ACCESSORS = [:nonce, :name, :username, :email, :avatar_url, :avatar_force_update, :require_activation, :bio, :external_id, :return_sso_url, :admin, :moderator, :suppress_welcome_message, :title, :add_groups, :remove_groups, :groups, :profile_background_url, :card_background_url] FIXNUMS = [] BOOLS = [:avatar_force_update, :admin, :moderator, :require_activation, :suppress_welcome_message] NONCE_EXPIRY_TIME = 10.minutes attr_accessor(*ACCESSORS) attr_writer :sso_secret, :sso_url def self.sso_secret raise RuntimeError, "sso_secret not implemented on class, be sure to set it on instance" end def self.sso_url raise RuntimeError, "sso_url not implemented on class, be sure to set it on instance" end def self.parse(payload, sso_secret = nil) sso = new sso.sso_secret = sso_secret if sso_secret parsed = Rack::Utils.parse_query(payload) if sso.sign(parsed["sso"]) != parsed["sig"] diags = "\n\nsso: #{parsed["sso"]}\n\nsig: #{parsed["sig"]}\n\nexpected sig: #{sso.sign(parsed["sso"])}" if parsed["sso"] =~ /[^a-zA-Z0-9=\r\n\/+]/m raise RuntimeError, "The SSO field should be Base64 encoded, using only A-Z, a-z, 0-9, +, /, and = characters. Your input contains characters we don't understand as Base64, see http://en.wikipedia.org/wiki/Base64 #{diags}" else raise RuntimeError, "Bad signature for payload #{diags}" end end decoded = Base64.decode64(parsed["sso"]) decoded_hash = Rack::Utils.parse_query(decoded) ACCESSORS.each do |k| val = decoded_hash[k.to_s] val = val.to_i if FIXNUMS.include? k if BOOLS.include? k val = ["true", "false"].include?(val) ? val == "true" : nil end sso.send("#{k}=", val) end decoded_hash.each do |k, v| if field = k[/^custom\.(.+)$/, 1] sso.custom_fields[field] = v end end sso end def diagnostics SingleSignOn::ACCESSORS.map { |a| "#{a}: #{send(a)}" }.join("\n") end def sso_secret @sso_secret || self.class.sso_secret end def sso_url @sso_url || self.class.sso_url end def custom_fields @custom_fields ||= {} end def sign(payload) OpenSSL::HMAC.hexdigest("sha256", sso_secret, payload) end def to_url(base_url = nil) base = "#{base_url || sso_url}" "#{base}#{base.include?('?') ? '&' : '?'}#{payload}" end def payload payload = Base64.strict_encode64(unsigned_payload) "sso=#{CGI::escape(payload)}&sig=#{sign(payload)}" end def unsigned_payload payload = {} ACCESSORS.each do |k| next if (val = send k) == nil payload[k] = val end @custom_fields&.each do |k, v| payload["custom.#{k}"] = v.to_s end Rack::Utils.build_query(payload) end end