Handle blocked access to local/session storage

client/src/PublicRequest.ts

@@ -230,6 +230,8 @@ export type KeyguardError = {
         CORE: 'Core',
         // used for internal keyguard Errors.
         KEYGUARD: 'Keyguard',
+        // used for errors caused by the browser and its configuration
+        BROWSER: 'Browser',
         // used for the remaining Errors which are not assigned an own type just yet.
         UNCLASSIFIED: 'Unclassified',
     },
@@ -246,5 +248,7 @@ export type KeyguardError = {
         KEY_NOT_FOUND: 'keyId not found',
         // network name does not exist
         INVALID_NETWORK_CONFIG: 'Invalid network config',
+        // when the browser prevents access to LocalStorage or SessionStorage (because of privacy settings)
+        NO_STORAGE_ACCESS: 'Cannot access browser storage because of privacy settings',
     },
 };

src/components/TabWidthSelector.js

@@ -12,7 +12,13 @@ class TabWidthSelector extends Nimiq.Observable {
         this.$el = TabWidthSelector._createElement($el);
 
         // Load last used width from localStorage.
-        this._tabWidth = localStorage.getItem(TabWidthSelector.LOCALSTORAGE_KEY) || TabWidthSelector.DEFAULT_TAB_WIDTH;
+        try {
+            /** @type {string} */
+            this._tabWidth = localStorage.getItem(TabWidthSelector.LOCALSTORAGE_KEY) || '';
+        } catch (error) {
+            // Ignore
+        }
+        this._tabWidth = this._tabWidth || TabWidthSelector.DEFAULT_TAB_WIDTH;
         this._updateClasses();
 
         this.$width2Button = /** @type {HTMLButtonElement} */ (this.$el.querySelector('button[data-width="2"]'));
@@ -67,7 +73,11 @@ class TabWidthSelector extends Nimiq.Observable {
     _updateWidth(width) {
         this._tabWidth = width;
         this._updateClasses();
-        localStorage.setItem(TabWidthSelector.LOCALSTORAGE_KEY, this._tabWidth);
+        try {
+            localStorage.setItem(TabWidthSelector.LOCALSTORAGE_KEY, this._tabWidth);
+        } catch (error) {
+            // Ignore
+        }
         this.fire(TabWidthSelector.Events.INPUT, this._tabWidth);
     }
 

src/lib/ErrorConstants.js

@@ -7,6 +7,8 @@ const ErrorConstants = {
         CORE: 'Core',
         // used for other internal keyguard Errors.
         KEYGUARD: 'Keyguard',
+        // used for errors caused by the browser and its configuration
+        BROWSER: 'Browser',
         // used for the remaining Errors which are not assigned an own type just yet.
         UNCLASSIFIED: 'Unclassified',
     },
@@ -23,6 +25,8 @@ const ErrorConstants = {
         KEY_NOT_FOUND: 'keyId not found',
         // network name does not exist
         INVALID_NETWORK_CONFIG: 'Invalid network config',
+        // when the browser prevents access to LocalStorage or SessionStorage (because of privacy settings)
+        NO_STORAGE_ACCESS: 'Cannot access browser storage because of privacy settings',
     },
 };
 

src/lib/Errors.js

@@ -54,6 +54,15 @@ Errors.KeyguardError = class extends Errors.BaseError {
     }
 };
 
+Errors.BrowserError = class extends Errors.BaseError {
+    /**
+     *  @param {string|Error} [messageOrError]
+     */
+    constructor(messageOrError) {
+        super(ErrorConstants.Types.BROWSER, messageOrError);
+    }
+};
+
 Errors.UnclassifiedError = class extends Errors.BaseError {
     /**
      *  @param {string|Error} [messageOrError]

src/lib/RpcServer.es.js

@@ -250,11 +250,15 @@ class RpcServer { // eslint-disable-line no-unused-vars
         // Check for a stored request referenced by a URL 'id' parameter
         const searchParams = new URLSearchParams(window.location.search);
         if (searchParams.has(UrlRpcEncoder.URL_SEARCHPARAM_NAME)) {
-            const storedRequest = window.sessionStorage.getItem(
-                `request-${searchParams.get(UrlRpcEncoder.URL_SEARCHPARAM_NAME)}`,
-            );
-            if (storedRequest) {
-                return this._receive(JsonUtils.parse(storedRequest), false);
+            try {
+                const storedRequest = window.sessionStorage.getItem(
+                    `request-${searchParams.get(UrlRpcEncoder.URL_SEARCHPARAM_NAME)}`,
+                );
+                if (storedRequest) {
+                    return this._receive(JsonUtils.parse(storedRequest), false);
+                }
+            } catch (error) {
+                // Ignore SessionStorage access error
             }
         }
 
@@ -292,7 +296,11 @@ class RpcServer { // eslint-disable-line no-unused-vars
             console.debug('RpcServer ACCEPT', state.data);
 
             if (persistMessage) {
-                sessionStorage.setItem(`request-${state.data.id}`, JsonUtils.stringify(state.toRequestObject()));
+                try {
+                    sessionStorage.setItem(`request-${state.data.id}`, JsonUtils.stringify(state.toRequestObject()));
+                } catch (error) {
+                    // Ignore SessionStorage access error
+                }
             }
 
             // Call method

src/request/import/ImportApi.js

@@ -2,6 +2,7 @@
 /* global ImportFile */
 /* global ImportWords */
 /* global Errors */
+/* global ErrorConstants */
 
 /** @extends {TopLevelApi<KeyguardRequest.ImportRequest>} */
 class ImportApi extends TopLevelApi {
@@ -14,6 +15,13 @@ class ImportApi extends TopLevelApi {
             throw new Errors.InvalidRequestError('request is required');
         }
 
+        try {
+            sessionStorage.setItem('_test', 'write-access');
+            sessionStorage.removeItem('_test');
+        } catch (e) {
+            throw new Errors.BrowserError(ErrorConstants.Messages.NO_STORAGE_ACCESS);
+        }
+
         const parsedRequest = {};
         parsedRequest.appName = this.parseAppName(request.appName);
         parsedRequest.requestedKeyPaths = this.parsePathsArray(request.requestedKeyPaths, ' requestedKeyPaths');