From 7cbfd48873c0f0039e3371d1a68b29adc088cc1a Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <richard@matrix.org>
Date: Wed, 24 May 2023 15:14:48 +0100
Subject: [PATCH] Fixes and comments

---
 src/components/views/settings/devices/types.ts |  8 +++++++-
 src/utils/device/isDeviceVerified.ts           | 10 +++++++---
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/src/components/views/settings/devices/types.ts b/src/components/views/settings/devices/types.ts
index 36343cf22c03..5b073831733d 100644
--- a/src/components/views/settings/devices/types.ts
+++ b/src/components/views/settings/devices/types.ts
@@ -18,7 +18,13 @@ import { IMyDevice } from "matrix-js-sdk/src/matrix";
 
 import { ExtendedDeviceInformation } from "../../../../utils/device/parseUserAgent";
 
-export type DeviceWithVerification = IMyDevice & { isVerified: boolean | null };
+export type DeviceWithVerification = IMyDevice & {
+    /**
+     * `null` if the device is unknown or has not published encryption keys; otherwise a boolean
+     * indicating whether the device has been cross-signed by a cross-signing key we trust.
+     */
+    isVerified: boolean | null;
+};
 export type ExtendedDeviceAppInfo = {
     // eg Element Web
     appName?: string;
diff --git a/src/utils/device/isDeviceVerified.ts b/src/utils/device/isDeviceVerified.ts
index 1671fa01a303..3aabf264db14 100644
--- a/src/utils/device/isDeviceVerified.ts
+++ b/src/utils/device/isDeviceVerified.ts
@@ -22,13 +22,17 @@ import { MatrixClient } from "matrix-js-sdk/src/matrix";
  * @param client - reference to the MatrixClient
  * @param deviceId - ID of the device to be checked
  *
- * @returns `true` if the device has been correctly cross-signed. `false` if the device is unknown or not correctly
- *    cross-signed. `null` if there was an error fetching the device info.
+ * @returns `null` if the device is unknown or has not published encryption keys; otherwise a boolean
+ *    indicating whether the device has been cross-signed by a cross-signing key we trust.
  */
 export const isDeviceVerified = async (client: MatrixClient, deviceId: string): Promise<boolean | null> => {
     try {
         const trustLevel = await client.getCrypto()?.getDeviceVerificationStatus(client.getSafeUserId(), deviceId);
-        return trustLevel?.crossSigningVerified ?? false;
+        if (!trustLevel) {
+            // either no crypto, or an unknown/no-e2e device
+            return null;
+        }
+        return trustLevel.crossSigningVerified;
     } catch (e) {
         console.error("Error getting device cross-signing info", e);
         return null;