move various angular bits into shared jslib

src/angular/services/auth-guard.service.ts

@@ -0,0 +1,31 @@
+import { Injectable } from '@angular/core';
+import {
+    CanActivate,
+    Router,
+} from '@angular/router';
+
+import { CryptoService } from '../../abstractions/crypto.service';
+import { MessagingService } from '../../abstractions/messaging.service';
+import { UserService } from '../../abstractions/user.service';
+
+@Injectable()
+export class AuthGuardService implements CanActivate {
+    constructor(private cryptoService: CryptoService, private userService: UserService, private router: Router,
+        private messagingService: MessagingService) { }
+
+    async canActivate() {
+        const isAuthed = await this.userService.isAuthenticated();
+        if (!isAuthed) {
+            this.messagingService.send('logout');
+            return false;
+        }
+
+        const key = await this.cryptoService.getKey();
+        if (key == null) {
+            this.router.navigate(['lock']);
+            return false;
+        }
+
+        return true;
+    }
+}