Add support for device dehydration v2

src/async-components/views/dialogs/security/CreateSecretStorageDialog.tsx

@@ -398,7 +398,7 @@ export default class CreateSecretStorageDialog extends React.PureComponent<IProp
                     },
                 });
             }
-            initializeDehydration(true);
+            await initializeDehydration(true);
 
             this.setState({
                 phase: Phase.Stored,

src/components/views/right_panel/UserInfo.tsx

@@ -296,6 +296,11 @@ function DevicesSection({
             dehydratedDeviceIds.push(device.deviceId);
         }
     }
+    // If the user has exactly one device marked as dehydrated, we consider
+    // that as the dehydrated device, and hide it as a normal device (but
+    // indicate that the user is using a dehydrated device).  If the user has
+    // more than one, that is anomalous, and we show all the devices so that
+    // nothing is hidden.
     const dehydratedDeviceId: string | undefined = dehydratedDeviceIds.length == 1 ? dehydratedDeviceIds[0] : undefined;
     let dehydratedDeviceInExpandSection = false;
 

src/components/views/settings/devices/useOwnDevices.ts

@@ -138,10 +138,14 @@ export const useOwnDevices = (): DevicesState => {
             const dehydratedDeviceIds: string[] = [];
             for (const device of userDevices?.values() ?? []) {
                 if (device.dehydrated) {
-                    logger.debug("Found dehydrated device", device.deviceId);
                     dehydratedDeviceIds.push(device.deviceId);
                 }
             }
+            // If the user has exactly one device marked as dehydrated, we consider
+            // that as the dehydrated device, and hide it as a normal device (but
+            // indicate that the user is using a dehydrated device).  If the user has
+            // more than one, that is anomalous, and we show all the devices so that
+            // nothing is hidden.
             setDehydratedDeviceId(dehydratedDeviceIds.length == 1 ? dehydratedDeviceIds[0] : undefined);
 
             setIsLoadingDeviceList(false);

src/stores/SetupEncryptionStore.ts

@@ -112,11 +112,12 @@ export class SetupEncryptionStore extends EventEmitter {
         const userDevices: Iterable<Device> =
             (await crypto.getUserDeviceInfo([ownUserId])).get(ownUserId)?.values() ?? [];
         this.hasDevicesToVerifyAgainst = await asyncSome(userDevices, async (device) => {
-            // ignore the dehydrated device
+            // Ignore dehydrated devices.  `dehydratedDevice` is set by the
+            // implementation of MSC2697, whereas MSC3814 proposes that devices
+            // should set a `dehydrated` flag in the device key.  We ignore
+            // both types of dehydrated devices.
             if (dehydratedDevice && device.deviceId == dehydratedDevice?.device_id) return false;
-            if (device.dehydrated) {
-                return false;
-            }
+            if (device.dehydrated) return false;
 
             // ignore devices without an identity key
             if (!device.getIdentityKey()) return false;

src/utils/device/dehydration.ts

@@ -18,40 +18,37 @@ import { logger } from "matrix-js-sdk/src/logger";
 
 import { MatrixClientPeg } from "../../MatrixClientPeg";
 
-// the interval between creating dehydrated devices
-const DEHYDRATION_INTERVAL = 7 * 24 * 60 * 60 * 1000;
-
-// check if device dehydration is enabled
-export async function deviceDehydrationEnabled(): Promise<boolean> {
+/**
+ * Check if device dehydration is enabled.
+ *
+ * Dehydration can only be enabled if encryption is available, and the crypto
+ * backend supports dehydration.
+ *
+ * Dehydration can currently only enabled by setting a flag in the .well-known file.
+ */
+async function deviceDehydrationEnabled(): Promise<boolean> {
     const crypto = MatrixClientPeg.safeGet().getCrypto();
     if (!crypto) {
         return false;
     }
     if (!(await crypto.isDehydrationSupported())) {
         return false;
     }
-    if (await crypto.isDehydrationKeyStored()) {
-        return true;
-    }
     const wellknown = await MatrixClientPeg.safeGet().waitForClientWellKnown();
     return !!wellknown?.["org.matrix.msc3814"];
 }
 
-// if dehydration is enabled, rehydrate a device (if available) and create
-// a new dehydrated device
-export async function initializeDehydration(reset?: boolean): Promise<void> {
+/**
+ * If dehydration is enabled, rehydrate a device (if available) and create
+ * a new dehydrated device.
+ *
+ * @param createNewKey: force a new dehydration key to be created, even if one
+ *   already exists.  This is used when we reset secret storage.
+ */
+export async function initializeDehydration(createNewKey: boolean = false): Promise<void> {
     const crypto = MatrixClientPeg.safeGet().getCrypto();
     if (crypto && (await deviceDehydrationEnabled())) {
         logger.log("Device dehydration enabled");
-        if (reset) {
-            await crypto.resetDehydrationKey();
-        } else {
-            try {
-                await crypto.rehydrateDeviceIfAvailable();
-            } catch (e) {
-                logger.error("Error rehydrating device:", e);
-            }
-        }
-        await crypto.scheduleDeviceDehydration(DEHYDRATION_INTERVAL);
+        await crypto.startDehydration(createNewKey);
     }
 }

test/components/views/settings/tabs/user/SecurityUserSettingsTab-test.tsx

@@ -26,6 +26,7 @@ import {
     mockClientMethodsDevice,
     mockPlatformPeg,
 } from "../../../../../test-utils";
+import { SDKContext, SdkContextClass } from "../../../../../../src/contexts/SDKContext";
 
 describe("<SecurityUserSettingsTab />", () => {
     const defaultProps = {
@@ -44,9 +45,14 @@ describe("<SecurityUserSettingsTab />", () => {
         getKeyBackupVersion: jest.fn(),
     });
 
+    const sdkContext = new SdkContextClass();
+    sdkContext.client = mockClient;
+
     const getComponent = () => (
         <MatrixClientContext.Provider value={mockClient}>
-            <SecurityUserSettingsTab {...defaultProps} />
+            <SDKContext.Provider value={sdkContext}>
+                <SecurityUserSettingsTab {...defaultProps} />
+            </SDKContext.Provider>
         </MatrixClientContext.Provider>
     );