Add new method for DAST site validation

config/feature_flags/development/dast_meta_tag_validation.yml

+---
+name: dast_meta_tag_validation
+introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/67945
+rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/337711
+milestone: '14.2'
+type: development
+group: group::dynamic analysis
+default_enabled: false

ee/app/assets/javascripts/security_configuration/dast_site_validation/components/dast_site_validation_modal.vue

@@ -16,11 +16,13 @@ import download from '~/lib/utils/downloader';
 import { cleanLeadingSeparator, joinPaths, stripPathTail } from '~/lib/utils/url_utility';
 import { __, s__ } from '~/locale';
 import ModalCopyButton from '~/vue_shared/components/modal_copy_button.vue';
+import glFeatureFlagMixin from '~/vue_shared/mixins/gl_feature_flags_mixin';
 import {
   DAST_SITE_VALIDATION_MODAL_ID,
   DAST_SITE_VALIDATION_HTTP_HEADER_KEY,
   DAST_SITE_VALIDATION_METHOD_HTTP_HEADER,
   DAST_SITE_VALIDATION_METHOD_TEXT_FILE,
+  DAST_SITE_VALIDATION_METHOD_META_TAG,
   DAST_SITE_VALIDATION_METHODS,
 } from '../constants';
 import dastSiteTokenCreateMutation from '../graphql/dast_site_token_create.mutation.graphql';
@@ -42,6 +44,7 @@ export default {
     GlSkeletonLoader,
     GlTruncate,
   },
+  mixins: [glFeatureFlagMixin()],
   props: {
     fullPath: {
       type: String,
@@ -82,7 +85,11 @@ export default {
       };
     },
     validationMethodOptions() {
-      return Object.values(DAST_SITE_VALIDATION_METHODS);
+      const options = Object.values(DAST_SITE_VALIDATION_METHODS);
+      if (!this.glFeatures.dastMetaTagValidation) {
+        return options.filter(({ value }) => value !== DAST_SITE_VALIDATION_METHOD_META_TAG);
+      }
+      return options;
     },
     urlObject() {
       try {
@@ -103,6 +110,9 @@ export default {
     isHttpHeaderValidation() {
       return this.validationMethod === DAST_SITE_VALIDATION_METHOD_HTTP_HEADER;
     },
+    isMetaTagValidation() {
+      return this.validationMethod === DAST_SITE_VALIDATION_METHOD_META_TAG;
+    },
     textFileName() {
       return `GitLab-DAST-Site-Validation-${this.token}.txt`;
     },
@@ -112,6 +122,9 @@ export default {
     httpHeader() {
       return `${DAST_SITE_VALIDATION_HTTP_HEADER_KEY}: ${this.token}`;
     },
+    metaTag() {
+      return `<meta name="gitlab-dast-validation" content="${this.token}">`;
+    },
   },
   watch: {
     targetUrl: {
@@ -253,6 +266,17 @@ export default {
           :modal-id="modalProps.id"
         />
       </gl-form-group>
+      <gl-form-group
+        v-else-if="isMetaTagValidation"
+        :label="s__('DastSiteValidation|Step 2 - Add following meta tag to your site')"
+      >
+        <code class="gl-p-3 gl-bg-black gl-text-white">{{ metaTag }}</code>
+        <modal-copy-button
+          :text="metaTag"
+          :title="s__('DastSiteValidation|Copy Meta tag to clipboard')"
+          :modal-id="modalProps.id"
+        />
+      </gl-form-group>
       <gl-form-group :label="locationStepLabel" class="mw-460">
         <gl-form-input-group>
           <template #prepend>

ee/app/assets/javascripts/security_configuration/dast_site_validation/constants.js

@@ -2,6 +2,7 @@ import { s__ } from '~/locale';
 
 export const DAST_SITE_VALIDATION_METHOD_TEXT_FILE = 'TEXT_FILE';
 export const DAST_SITE_VALIDATION_METHOD_HTTP_HEADER = 'HEADER';
+export const DAST_SITE_VALIDATION_METHOD_META_TAG = 'META_TAG';
 
 export const DAST_SITE_VALIDATION_METHODS = {
   [DAST_SITE_VALIDATION_METHOD_TEXT_FILE]: {
@@ -18,6 +19,13 @@ export const DAST_SITE_VALIDATION_METHODS = {
       locationStepLabel: s__('DastSiteValidation|Step 3 - Confirm header location and validate'),
     },
   },
+  [DAST_SITE_VALIDATION_METHOD_META_TAG]: {
+    value: DAST_SITE_VALIDATION_METHOD_META_TAG,
+    text: s__('DastSiteValidation|Meta tag validation'),
+    i18n: {
+      locationStepLabel: s__('DastSiteValidation|Step 3 - Confirm meta tag location and validate'),
+    },
+  },
 };
 
 export const DAST_SITE_VALIDATION_STATUS = {

ee/app/controllers/projects/security/dast_profiles_controller.rb

@@ -8,6 +8,7 @@ module Projects
       before_action do
         authorize_read_on_demand_scans!
         push_frontend_feature_flag(:dast_failed_site_validations, @project, default_enabled: :yaml)
+        push_frontend_feature_flag(:dast_meta_tag_validation, @project, default_enabled: :yaml)
       end
 
       feature_category :dynamic_application_security_testing

ee/spec/frontend/security_configuration/dast_profiles/dast_site_validation/components/dast_site_validation_modal_spec.js

@@ -22,7 +22,7 @@ const targetUrl = 'https://example.com/';
 const tokenId = '1';
 const token = 'validation-token-123';
 
-const validationMethods = ['text file', 'header'];
+const validationMethods = ['text file', 'header', 'meta tag'];
 
 const defaultProps = {
   fullPath,
@@ -57,6 +57,9 @@ describe('DastSiteValidationModal', () => {
             static: true,
             visible: true,
           },
+          provide: {
+            glFeatures: { dastMetaTagValidation: true },
+          },
         },
         mountOptions,
         {
@@ -284,6 +287,57 @@ describe('DastSiteValidationModal', () => {
         });
       });
     });
+
+    describe('meta tag validation', () => {
+      beforeEach(async () => {
+        createFullComponent();
+
+        await waitForPromises();
+
+        enableValidationMethod('meta tag');
+      });
+
+      it.each([
+        /step 2 - add following meta tag to your site/i,
+        /step 3 - confirm meta tag location and validate/i,
+      ])('shows the correct descriptions', (descriptionText) => {
+        expect(withinComponent().getByText(descriptionText)).not.toBe(null);
+      });
+
+      it('shows a code block containing the meta key with the given token', () => {
+        expect(
+          withinComponent().getByText(`<meta name="gitlab-dast-validation" content="${token}">`, {
+            selector: 'code',
+          }),
+        ).not.toBe(null);
+      });
+
+      it('shows a button that copies the meta tag to the clipboard', () => {
+        const clipboardButton = wrapper.find(ModalCopyButton);
+
+        expect(clipboardButton.exists()).toBe(true);
+        expect(clipboardButton.props()).toMatchObject({
+          text: `<meta name="gitlab-dast-validation" content="${token}">`,
+          title: 'Copy Meta tag to clipboard',
+        });
+      });
+    });
+  });
+
+  describe('with the dastMetaTagValidation feature flag disabled', () => {
+    beforeEach(() => {
+      createFullComponent({
+        provide: {
+          glFeatures: {
+            dastMetaTagValidation: false,
+          },
+        },
+      });
+    });
+
+    it('does not render the meta tag validation method', () => {
+      expect(findRadioInputForValidationMethod('meta tag')).toBe(null);
+    });
   });
 
   describe.each(validationMethods)('"%s" validation submission', (validationMethod) => {

locale/gitlab.pot

@@ -10438,6 +10438,9 @@ msgstr ""
 msgid "DastSiteValidation|Copy HTTP header to clipboard"
 msgstr ""
 
+msgid "DastSiteValidation|Copy Meta tag to clipboard"
+msgstr ""
+
 msgid "DastSiteValidation|Could not create validation token. Please try again."
 msgstr ""
 
@@ -10450,6 +10453,9 @@ msgstr ""
 msgid "DastSiteValidation|Header validation"
 msgstr ""
 
+msgid "DastSiteValidation|Meta tag validation"
+msgstr ""
+
 msgid "DastSiteValidation|Retry validation"
 msgstr ""
 
@@ -10462,12 +10468,18 @@ msgstr ""
 msgid "DastSiteValidation|Step 2 - Add following HTTP header to your site"
 msgstr ""
 
+msgid "DastSiteValidation|Step 2 - Add following meta tag to your site"
+msgstr ""
+
 msgid "DastSiteValidation|Step 2 - Add following text to the target site"
 msgstr ""
 
 msgid "DastSiteValidation|Step 3 - Confirm header location and validate"
 msgstr ""
 
+msgid "DastSiteValidation|Step 3 - Confirm meta tag location and validate"
+msgstr ""
+
 msgid "DastSiteValidation|Step 3 - Confirm text file location and validate"
 msgstr ""