Ignore unknown authncontext

app/controllers/openid_connect/authorization_controller.rb

@@ -174,6 +174,7 @@ def pre_validate_authorize_form
           user_fully_authenticated: user_fully_authenticated?,
           referer: request.referer,
           vtr_param: params[:vtr],
+          unknown_authn_contexts:,
         ),
       )
       return if result.success?
@@ -258,5 +259,12 @@ def redirect_user(redirect_uri, issuer, user_uuid)
     def sp_handoff_bouncer
       @sp_handoff_bouncer ||= SpHandoffBouncer.new(sp_session)
     end
+
+    def unknown_authn_contexts
+      return nil if params[:vtr].present? || params[:acr_values].blank?
+
+      (params[:acr_values].split - Saml::Idp::Constants::VALID_AUTHN_CONTEXTS).
+        join(' ').presence
+    end
   end
 end

app/controllers/saml_idp_controller.rb

@@ -131,6 +131,7 @@ def capture_analytics
       request_signed: saml_request.signed?,
       matching_cert_serial:,
       requested_nameid_format: saml_request.name_id_format,
+      unknown_authn_contexts:,
     )
 
     if result.success? && saml_request.signed?
@@ -151,12 +152,13 @@ def log_external_saml_auth_request
 
     analytics.saml_auth_request(
       requested_ial: requested_ial,
-      authn_context: saml_request&.requested_authn_contexts,
+      authn_context: requested_authn_contexts,
       requested_aal_authn_context: FederatedProtocols::Saml.new(saml_request).aal,
       requested_vtr_authn_contexts: saml_request&.requested_vtr_authn_contexts.presence,
       force_authn: saml_request&.force_authn?,
       final_auth_request: sp_session[:final_auth_request],
       service_provider: saml_request&.issuer,
+      unknown_authn_contexts:,
       user_fully_authenticated: user_fully_authenticated?,
     )
   end
@@ -227,4 +229,25 @@ def resolved_authn_context_int_ial
   def require_path_year
     render_not_found if params[:path_year].blank?
   end
+
+  def unknown_authn_contexts
+    return nil if saml_request.requested_vtr_authn_contexts.present?
+    return nil if requested_authn_contexts.blank?
+
+    unmatched_authn_contexts.reject do |authn_context|
+      authn_context.match(req_attrs_regexp)
+    end.join(' ').presence
+  end
+
+  def unmatched_authn_contexts
+    requested_authn_contexts - Saml::Idp::Constants::VALID_AUTHN_CONTEXTS
+  end
+
+  def requested_authn_contexts
+    @request_authn_contexts || saml_request&.requested_authn_contexts
+  end
+
+  def req_attrs_regexp
+    Regexp.escape(Saml::Idp::Constants::REQUESTED_ATTRIBUTES_CLASSREF)
+  end
 end

app/services/analytics_events.rb

@@ -5526,6 +5526,7 @@ def openid_connect_bearer_token(success:, ial:, client_id:, errors:, error_detai
   # @param [String, nil] vtr_param
   # @param [Boolean] unauthorized_scope
   # @param [Boolean] user_fully_authenticated
+  # @param [String] unknown_authn_contexts space separated list of unknown contexts
   def openid_connect_request_authorization(
     success:,
     errors:,
@@ -5542,6 +5543,7 @@ def openid_connect_request_authorization(
     unauthorized_scope:,
     user_fully_authenticated:,
     error_details: nil,
+    unknown_authn_contexts: nil,
     **extra
   )
     track_event(
@@ -5561,6 +5563,7 @@ def openid_connect_request_authorization(
       vtr_param:,
       unauthorized_scope:,
       user_fully_authenticated:,
+      unknown_authn_contexts:,
       **extra,
     )
   end
@@ -6337,6 +6340,7 @@ def rules_of_use_visit
   # matches the request certificate in a successful, signed request
   # @param [Hash] cert_error_details Details for errors that occurred because of an invalid
   # signature
+  # @param [String] unknown_authn_contexts space separated list of unknown contexts
   def saml_auth(
     success:,
     errors:,
@@ -6353,6 +6357,7 @@ def saml_auth(
     matching_cert_serial:,
     error_details: nil,
     cert_error_details: nil,
+    unknown_authn_contexts: nil,
     **extra
   )
     track_event(
@@ -6372,6 +6377,7 @@ def saml_auth(
       request_signed:,
       matching_cert_serial:,
       cert_error_details:,
+      unknown_authn_contexts:,
       **extra,
     )
   end
@@ -6383,6 +6389,7 @@ def saml_auth(
   # @param [Boolean] force_authn
   # @param [Boolean] final_auth_request
   # @param [String] service_provider
+  # @param [String] unknown_authn_contexts space separated list of unknown contexts
   # @param [Boolean] user_fully_authenticated
   # An external request for SAML Authentication was received
   def saml_auth_request(
@@ -6393,6 +6400,7 @@ def saml_auth_request(
     force_authn:,
     final_auth_request:,
     service_provider:,
+    unknown_authn_contexts:,
     user_fully_authenticated:,
     **extra
   )
@@ -6405,6 +6413,7 @@ def saml_auth_request(
       force_authn:,
       final_auth_request:,
       service_provider:,
+      unknown_authn_contexts:,
       user_fully_authenticated:,
       **extra,
     )

app/services/saml_request_validator.rb

@@ -88,7 +88,10 @@ def valid_authn_context?
       next true if classref.match?(SamlIdp::Request::VTR_REGEXP) &&
                    IdentityConfig.store.use_vot_in_sp_requests
     end
-    authn_contexts.all? do |classref|
+    # SAML requests are allowed to "default" to the integration's IAL default.
+    return true if authn_contexts.empty?
+
+    authn_contexts.any? do |classref|
       valid_contexts.include?(classref)
     end
   end

app/services/vot/parser.rb

@@ -4,8 +4,6 @@ module Vot
   class Parser
     class ParseException < StandardError; end
 
-    class UnsupportedComponentsException < ParseException; end
-
     class DuplicateComponentsException < ParseException; end
 
     Result = Data.define(
@@ -87,8 +85,7 @@ def initial_components
       @initial_components ||= component_string.split(component_separator).map do |component_name|
         component_map.fetch(component_name)
       rescue KeyError
-        raise_unsupported_component_exception(component_name)
-      end
+      end.compact
     end
 
     def component_separator
@@ -113,16 +110,6 @@ def validate_component_uniqueness!(component_values)
       end
     end
 
-    def raise_unsupported_component_exception(component_value_name)
-      if vector_of_trust.present?
-        raise UnsupportedComponentsException,
-              "'#{vector_of_trust}' contains unknown component '#{component_value_name}'"
-      else
-        raise UnsupportedComponentsException,
-              "'#{acr_values}' contains unknown acr value '#{component_value_name}'"
-      end
-    end
-
     def raise_duplicate_component_exception
       if vector_of_trust.present?
         raise DuplicateComponentsException, "'#{vector_of_trust}' contains duplicate components"

spec/controllers/application_controller_spec.rb

@@ -477,7 +477,7 @@ def index
       let(:vtr) { nil }
       let(:acr_values) do
         [
-          'http://idmanagement.gov/ns/assurance/aal/1',
+          Saml::Idp::Constants::DEFAULT_AAL_AUTHN_CONTEXT_CLASSREF,
         ].join(' ')
       end
 
@@ -486,6 +486,31 @@ def index
         expect(result.identity_proofing?).to eq(true)
       end
 
+      context 'when an unknown acr value is passed in' do
+        let(:acr_values) { 'unknown-acr-value' }
+
+        it 'raises an exception' do
+          expect { result }.to raise_exception(
+            Vot::Parser::ParseException,
+            'VoT parser called without VoT or ACR values',
+          )
+        end
+
+        context 'with a known acr value' do
+          let(:acr_values) do
+            [
+              Saml::Idp::Constants::DEFAULT_AAL_AUTHN_CONTEXT_CLASSREF,
+              'unknown-acr-value',
+            ].join(' ')
+          end
+
+          it 'returns a resolved authn context result' do
+            expect(result.aal2?).to eq(true)
+            expect(result.identity_proofing?).to eq(true)
+          end
+        end
+      end
+
       context 'without an SP' do
         let(:sp) { nil }
         let(:sp_session) { nil }

spec/controllers/openid_connect/authorization_controller_spec.rb

@@ -2029,6 +2029,65 @@
         end
       end
 
+      context 'when there are unknown acr_values params' do
+        let(:unknown_value) { 'unknown-acr-value' }
+        let(:acr_values) { unknown_value }
+
+        context 'when there is only an unknown acr_value' do
+          it 'tracks the event with errors' do
+            stub_analytics
+
+            action
+
+            expect(@analytics).to have_logged_event(
+              'OpenID Connect: authorization request',
+              success: false,
+              client_id:,
+              prompt:,
+              allow_prompt_login: true,
+              unauthorized_scope: false,
+              errors: hash_including(:acr_values),
+              error_details: hash_including(:acr_values),
+              user_fully_authenticated: true,
+              acr_values: '',
+              code_challenge_present: false,
+              scope: 'openid profile',
+              unknown_authn_contexts: unknown_value,
+            )
+          end
+
+          context 'when there is also a valid acr_value' do
+            let(:known_value) { Saml::Idp::Constants::IAL2_AUTHN_CONTEXT_CLASSREF }
+            let(:acr_values) do
+              [
+                unknown_value,
+                known_value,
+              ].join(' ')
+            end
+
+            it 'tracks the event' do
+              stub_analytics
+
+              action
+              expect(@analytics).to have_logged_event(
+                'OpenID Connect: authorization request',
+                success: true,
+                client_id:,
+                prompt:,
+                allow_prompt_login: true,
+                unauthorized_scope: false,
+                user_fully_authenticated: true,
+                acr_values: known_value,
+                code_challenge_present: false,
+                scope: 'openid profile',
+                unknown_authn_contexts: unknown_value,
+                errors: {},
+              )
+            end
+          end
+        end
+      end
+
       context 'vtr with invalid params that do not interfere with the redirect_uri' do
         let(:acr_values) { nil }
         let(:vtr) { ['C1'].to_json }

spec/controllers/saml_idp_controller_spec.rb

@@ -970,15 +970,22 @@ def name_id_version(format_urn)
     end
 
     context 'authn_context is invalid' do
-      it 'renders an error page' do
+      let(:unknown_value) do
+        'http://idmanagement.gov/ns/assurance/loa/5'
+      end
+      let(:authn_context) { unknown_value }
+
+      before do
         stub_analytics
 
         saml_get_auth(
           saml_settings(
-            overrides: { authn_context: 'http://idmanagement.gov/ns/assurance/loa/5' },
+            overrides: { authn_context: },
           ),
         )
+      end
 
+      it 'renders an error page' do
         expect(controller).to render_template('saml_idp/auth/error')
         expect(response.status).to eq(400)
         expect(response.body).to include(t('errors.messages.unauthorized_authn_context'))
@@ -989,7 +996,7 @@ def name_id_version(format_urn)
             errors: { authn_context: [t('errors.messages.unauthorized_authn_context')] },
             error_details: { authn_context: { unauthorized_authn_context: true } },
             nameid_format: Saml::Idp::Constants::NAME_ID_FORMAT_PERSISTENT,
-            authn_context: ['http://idmanagement.gov/ns/assurance/loa/5'],
+            authn_context: [unknown_value],
             authn_context_comparison: 'exact',
             service_provider: 'http://localhost:3000',
             request_signed: true,
@@ -998,9 +1005,49 @@ def name_id_version(format_urn)
             idv: false,
             finish_profile: false,
             matching_cert_serial: saml_test_sp_cert_serial,
+            unknown_authn_contexts: unknown_value,
           ),
         )
       end
+
+      context 'there is also a valid authn_context' do
+        let(:authn_context) do
+          [
+            Saml::Idp::Constants::IAL1_AUTHN_CONTEXT_CLASSREF,
+            unknown_value,
+          ]
+        end
+
+        it 'logs the unknown authn_context value' do
+          expect(response.status).to eq(302)
+          expect(@analytics).to have_logged_event(
+            'SAML Auth Request',
+            hash_including(
+              unknown_authn_contexts: unknown_value,
+            ),
+          )
+        end
+
+        context 'when it includes the ReqAttributes AuthnContext' do
+          let(:authn_context) do
+            [
+              Saml::Idp::Constants::REQUESTED_ATTRIBUTES_CLASSREF,
+              Saml::Idp::Constants::IAL1_AUTHN_CONTEXT_CLASSREF,
+              unknown_value,
+            ]
+          end
+
+          it 'logs the unknown authn_context value' do
+            expect(response.status).to eq(302)
+            expect(@analytics).to have_logged_event(
+              'SAML Auth Request',
+              hash_including(
+                unknown_authn_contexts: unknown_value,
+              ),
+            )
+          end
+        end
+      end
     end
 
     context 'authn_context scenarios' do