Remove feature_dehydration

src/Lifecycle.ts

@@ -799,18 +799,6 @@ async function doSetLoggedIn(
         PosthogAnalytics.instance.startListeningToSettingsChanges(client);
     }
 
-    if (credentials.freshLogin && SettingsStore.getValue("feature_dehydration")) {
-        // If we just logged in, try to rehydrate a device instead of using a
-        // new device.  If it succeeds, we'll get a new device ID, so make sure
-        // we persist that ID to localStorage
-        const newDeviceId = await client.rehydrateDevice();
-        if (newDeviceId) {
-            credentials.deviceId = newDeviceId;
-        }
-
-        delete credentials.freshLogin;
-    }
-
     if (localStorage) {
         try {
             await persistCredentials(credentials);

src/SecurityManager.ts

@@ -16,7 +16,6 @@ import { MatrixClientPeg } from "./MatrixClientPeg";
 import { _t } from "./languageHandler";
 import { isSecureBackupRequired } from "./utils/WellKnownUtils";
 import AccessSecretStorageDialog, { KeyParams } from "./components/views/dialogs/security/AccessSecretStorageDialog";
-import SettingsStore from "./settings/SettingsStore";
 import { ModuleRunner } from "./modules/ModuleRunner";
 import QuestionDialog from "./components/views/dialogs/QuestionDialog";
 import InteractiveAuthDialog from "./components/views/dialogs/InteractiveAuthDialog";
@@ -278,14 +277,7 @@ async function doAccessSecretStorage(func: () => Promise<void>, forceReset: bool
             await crypto.bootstrapSecretStorage({});
 
             const keyId = Object.keys(secretStorageKeys)[0];
-            if (keyId && SettingsStore.getValue("feature_dehydration")) {
-                let dehydrationKeyInfo = {};
-                if (secretStorageKeyInfo[keyId] && secretStorageKeyInfo[keyId].passphrase) {
-                    dehydrationKeyInfo = { passphrase: secretStorageKeyInfo[keyId].passphrase };
-                }
-                logger.log("accessSecretStorage: Setting dehydration key");
-                await cli.setDehydrationKey(secretStorageKeys[keyId], dehydrationKeyInfo, "Backup device");
-            } else if (!keyId) {
+            if (!keyId) {
                 logger.warn("accessSecretStorage: Not setting dehydration key: no SSSS key found");
             } else {
                 logger.log("accessSecretStorage: Not setting dehydration key: feature disabled");

src/settings/Settings.tsx

@@ -303,14 +303,6 @@ export const SETTINGS: { [setting: string]: ISetting } = {
         supportedLevelsAreOrdered: true,
         default: false,
     },
-    "feature_dehydration": {
-        isFeature: true,
-        labsGroup: LabGroup.Encryption,
-        displayName: _td("labs|dehydration"),
-        supportedLevels: LEVELS_DEVICE_ONLY_SETTINGS_WITH_CONFIG_PRIORITISED,
-        supportedLevelsAreOrdered: true,
-        default: false,
-    },
     "feature_exclude_insecure_devices": {
         isFeature: true,
         labsGroup: LabGroup.Encryption,