feat: support per-technique filtering of custom context menu items (#92)

README.md

@@ -169,6 +169,23 @@ Example custom context menu objects:
 }
 ```
 
+By default a custom context menu option is shown for every technique. To restrict an option to specific techniques, add a `limit_techniques` array to the object. Each entry can be either:
+
+* a bare ATT&CK ID string, e.g. `"T1059"`, which applies the option to that technique under any tactic it appears in, or
+* an object of the form `{ "id": "T1059", "tactic": "execution" }`, which applies the option to that technique only when viewed under the given tactic (tactic in shortname/phase-name format, same convention used by the optional `tactic` field on technique objects in the [layer format](layers/README.md)). This is useful for multi-tactic techniques where the option should only make sense under one of their tactics.
+
+If `limit_techniques` is omitted (or empty), the option applies to every technique, matching the previous default behavior.
+
+Example restricted to one technique under all of its tactics, and one technique under a single tactic:
+
+```json
+{
+    "label": "example restricted option",
+    "url": "https://test.com",
+    "limit_techniques": ["T1098", { "id": "T1059", "tactic": "execution" }]
+}
+```
+
 ## Methods for loading content
 
 ### Loading content from a Collection Index

nav-app/src/app/classes/context-menu-item.spec.ts

@@ -0,0 +1,60 @@
+import { ContextMenuItem } from './context-menu-item';
+import { Technique } from './stix/technique';
+import { Tactic } from './stix/tactic';
+
+// appliesTo() only reads technique.attackID and tactic.shortname, so lightweight
+// fixtures are cast rather than constructing full StixObject/DataService graphs.
+function fakeTechnique(attackID: string): Technique {
+    return { attackID } as unknown as Technique;
+}
+
+function fakeTactic(shortname: string): Tactic {
+    return { shortname } as unknown as Tactic;
+}
+
+describe('ContextMenuItem.appliesTo', () => {
+    const t1059 = fakeTechnique('T1059');
+    const t1098 = fakeTechnique('T1098');
+    const execution = fakeTactic('execution');
+    const persistence = fakeTactic('persistence');
+
+    it('applies to every technique when limit_techniques is not set', () => {
+        const item = new ContextMenuItem('label', 'url');
+        expect(item.appliesTo(t1059, execution)).toBeTrue();
+        expect(item.appliesTo(t1098, persistence)).toBeTrue();
+    });
+
+    it('applies to every technique when limit_techniques is an empty array', () => {
+        const item = new ContextMenuItem('label', 'url', null, []);
+        expect(item.appliesTo(t1059, execution)).toBeTrue();
+    });
+
+    it('matches a bare ATT&CK ID entry regardless of tactic', () => {
+        const item = new ContextMenuItem('label', 'url', null, ['T1059']);
+        expect(item.appliesTo(t1059, execution)).toBeTrue();
+        expect(item.appliesTo(t1059, persistence)).toBeTrue();
+    });
+
+    it('does not match a bare ATT&CK ID entry for a different technique', () => {
+        const item = new ContextMenuItem('label', 'url', null, ['T1059']);
+        expect(item.appliesTo(t1098, execution)).toBeFalse();
+    });
+
+    it('matches an { id, tactic } entry only under the specified tactic', () => {
+        const item = new ContextMenuItem('label', 'url', null, [{ id: 'T1059', tactic: 'execution' }]);
+        expect(item.appliesTo(t1059, execution)).toBeTrue();
+        expect(item.appliesTo(t1059, persistence)).toBeFalse();
+    });
+
+    it('does not match an { id, tactic } entry for a different technique', () => {
+        const item = new ContextMenuItem('label', 'url', null, [{ id: 'T1059', tactic: 'execution' }]);
+        expect(item.appliesTo(t1098, execution)).toBeFalse();
+    });
+
+    it('supports a mixed list of bare IDs and { id, tactic } entries', () => {
+        const item = new ContextMenuItem('label', 'url', null, ['T1098', { id: 'T1059', tactic: 'execution' }]);
+        expect(item.appliesTo(t1098, persistence)).toBeTrue(); // bare ID, any tactic
+        expect(item.appliesTo(t1059, execution)).toBeTrue(); // scoped match
+        expect(item.appliesTo(t1059, persistence)).toBeFalse(); // scoped, wrong tactic
+    });
+});

nav-app/src/app/classes/context-menu-item.ts

@@ -1,15 +1,47 @@
 import { Tactic } from './stix/tactic';
 import { Technique } from './stix/technique';
 
+/**
+ * A single entry in a ContextMenuItem's limit_techniques filter.
+ * A bare ATT&CK ID (e.g. "T1059") applies to that technique under any tactic it
+ * appears in. An { id, tactic } pair scopes the entry to that technique under
+ * one specific tactic (tactic given in shortname/phase-name format, matching
+ * the optional `tactic` field on technique objects in the layer format).
+ */
+export type ContextMenuTechniqueFilter = string | { id: string; tactic: string };
+
 export class ContextMenuItem {
     public readonly label: string;
     private readonly url: string;
     private readonly subtechnique_url: string;
+    private readonly limit_techniques: ContextMenuTechniqueFilter[];
 
-    constructor(label, url, subtechnique_url = null) {
+    constructor(label, url, subtechnique_url = null, limit_techniques: ContextMenuTechniqueFilter[] = null) {
         this.label = label;
         this.url = url;
         this.subtechnique_url = subtechnique_url;
+        this.limit_techniques = limit_techniques;
+    }
+
+    /**
+     * Determine whether this custom context menu item should be shown for the
+     * given technique/tactic combination.
+     *
+     * If limit_techniques is not set (or empty), the item applies to every
+     * technique, preserving the existing default behavior. Otherwise the item
+     * only applies if the technique matches a bare-ID entry, or matches an
+     * { id, tactic } entry under the specific tactic being viewed.
+     * @param {Technique} technique the technique the context menu was opened on
+     * @param {Tactic} tactic the tactic column the technique is being viewed under
+     * @returns {boolean} true if this item should be shown for this technique/tactic
+     */
+    public appliesTo(technique: Technique, tactic: Tactic): boolean {
+        if (!this.limit_techniques || this.limit_techniques.length === 0) return true;
+
+        return this.limit_techniques.some((entry) => {
+            if (typeof entry === 'string') return entry === technique.attackID;
+            return entry.id === technique.attackID && entry.tactic === tactic.shortname;
+        });
     }
 
     public getReplacedURL(technique: Technique, tactic: Tactic): string {

nav-app/src/app/matrix/technique-cell/contextmenu/contextmenu.component.html

@@ -31,10 +31,10 @@
             <div class="contextMenu-button" (click)="viewTechnique()">view technique</div>
             <div class="contextMenu-button" (click)="viewTactic()">view tactic</div>
         </div>
-        <div class="contextMenu-section" *ngIf="configService.contextMenuItems.length > 0">
+        <div class="contextMenu-section" *ngIf="applicableContextMenuItems.length > 0">
             <div
                 class="contextMenu-button"
-                *ngFor="let contextMenuItem of configService.contextMenuItems"
+                *ngFor="let contextMenuItem of applicableContextMenuItems"
                 (click)="openCustomContextMenuItem(contextMenuItem)">
                 {{ contextMenuItem.label }}
             </div>

nav-app/src/app/matrix/technique-cell/contextmenu/contextmenu.component.ts

@@ -28,6 +28,15 @@ export class ContextmenuComponent extends CellPopover implements OnInit {
         return this.techniqueVM.links;
     }
 
+    /**
+     * Custom context menu items configured in assets/config.json, filtered down to
+     * the ones applicable to the technique/tactic this menu was opened on (see
+     * ContextMenuItem#appliesTo and the optional limit_techniques config field).
+     */
+    public get applicableContextMenuItems(): ContextMenuItem[] {
+        return this.configService.contextMenuItems.filter((item) => item.appliesTo(this.technique, this.tactic));
+    }
+
     constructor(
         private element: ElementRef,
         public configService: ConfigService,

nav-app/src/app/services/config.service.ts

@@ -208,7 +208,9 @@ export class ConfigService {
                     console.debug('loaded app configuration settings');
 
                     config['custom_context_menu_items'].forEach((item) => {
-                        this.contextMenuItems.push(new ContextMenuItem(item.label, item.url, item.subtechnique_url));
+                        this.contextMenuItems.push(
+                            new ContextMenuItem(item.label, item.url, item.subtechnique_url, item.limit_techniques)
+                        );
                     });
                     this.defaultLayers = config['default_layers'];
                     this.commentColor = config['comment_color'];