From ec7e69adc01309e5970bcdd9bde398c3284bcbdc Mon Sep 17 00:00:00 2001
From: hc-github-team-secure-vault-core
 <82990506+hc-github-team-secure-vault-core@users.noreply.github.com>
Date: Fri, 7 Jul 2023 14:01:33 -0400
Subject: [PATCH] backport of commit 9c8a7422ade1b46f413274c5eb6d5306c9e3e563
 (#21665)

Co-authored-by: Angel Garbarino <Monkeychip@users.noreply.github.com>
---
 changelog/21503.txt            |  3 +++
 ui/app/lib/local-storage.js    | 16 +++++++++++++++-
 ui/app/routes/vault/cluster.js |  4 ++++
 3 files changed, 22 insertions(+), 1 deletion(-)
 create mode 100644 changelog/21503.txt

diff --git a/changelog/21503.txt b/changelog/21503.txt
new file mode 100644
index 000000000..a61b22ba8
--- /dev/null
+++ b/changelog/21503.txt
@@ -0,0 +1,3 @@
+```release-note:bug
+ui: Surface DOMException error when browser settings prevent localStorage.
+```
diff --git a/ui/app/lib/local-storage.js b/ui/app/lib/local-storage.js
index e3be3447b..b7aeb70b5 100644
--- a/ui/app/lib/local-storage.js
+++ b/ui/app/lib/local-storage.js
@@ -4,8 +4,22 @@
  */
 
 export default {
+  isLocalStorageSupported() {
+    try {
+      const key = `__storage__test`;
+      window.localStorage.setItem(key, null);
+      window.localStorage.removeItem(key);
+      return true;
+    } catch (e) {
+      // modify the e object so we can customize the error message.
+      // e.message is readOnly.
+      e.errors = [`This is likely due to your browser's cookie settings.`];
+      throw e;
+    }
+  },
+
   getItem(key) {
-    var item = window.localStorage.getItem(key);
+    const item = window.localStorage.getItem(key);
     return item && JSON.parse(item);
   },
 
diff --git a/ui/app/routes/vault/cluster.js b/ui/app/routes/vault/cluster.js
index 303bcc0b9..3e52da982 100644
--- a/ui/app/routes/vault/cluster.js
+++ b/ui/app/routes/vault/cluster.js
@@ -10,6 +10,7 @@ import Route from '@ember/routing/route';
 import { task, timeout } from 'ember-concurrency';
 import Ember from 'ember';
 import getStorage from '../../lib/token-storage';
+import localStorage from 'vault/lib/local-storage';
 import ClusterRoute from 'vault/mixins/cluster-route';
 import ModelBoundaryRoute from 'vault/mixins/model-boundary-route';
 
@@ -87,6 +88,9 @@ export default Route.extend(ModelBoundaryRoute, ClusterRoute, {
   },
 
   model(params) {
+    // if a user's browser settings block localStorage they will be unable to use Vault. The method will throw the error and the rest of the application will not load.
+    localStorage.isLocalStorageSupported();
+
     const id = this.getClusterId(params);
     return this.store.findRecord('cluster', id);
   },