Add key storage toggle to Encryption settings

playwright/e2e/settings/encryption-user-tab/encryption-tab.spec.ts

@@ -17,9 +17,7 @@ import {
 } from "../../crypto/utils";
 
 test.describe("Encryption tab", () => {
-    test.use({
-        displayName: "Alice",
-    });
+    test.use({ displayName: "Alice" });
 
     let recoveryKey: GeneratedSecretStorageKey;
     let expectedBackupVersion: string;
@@ -111,4 +109,36 @@ test.describe("Encryption tab", () => {
         // The user is prompted to reset their identity
         await expect(dialog.getByText("Forgot your recovery key? You’ll need to reset your identity.")).toBeVisible();
     });
+
+    test("should warn before turning off key storage", { tag: "@screenshot" }, async ({ page, app, util }) => {
+        await verifySession(app, recoveryKey.encodedPrivateKey);
+        await util.openEncryptionTab();
+
+        await page.getByRole("checkbox", { name: "Allow key storage" }).click();
+
+        await expect(
+            page.getByRole("heading", { name: "Are you sure you want to turn off key storage and delete it?" }),
+        ).toBeVisible();
+
+        await expect(util.getEncryptionTabContent()).toMatchScreenshot("delete-key-storage-confirm.png");
+
+        const deleteRequestPromises = [
+            page.waitForRequest((req) => req.url().endsWith("/account_data/m.cross_signing.master")),
+            page.waitForRequest((req) => req.url().endsWith("/account_data/m.cross_signing.self_signing")),
+            page.waitForRequest((req) => req.url().endsWith("/account_data/m.cross_signing.user_signing")),
+            page.waitForRequest((req) => req.url().endsWith("/account_data/m.megolm_backup.v1")),
+            page.waitForRequest((req) => req.url().endsWith("/account_data/m.secret_storage.default_key")),
+            page.waitForRequest((req) => req.url().includes("/account_data/m.secret_storage.key.")),
+        ];
+
+        await page.getByRole("button", { name: "Delete key storage" }).click();
+
+        await expect(page.getByRole("checkbox", { name: "Allow key storage" })).not.toBeChecked();
+
+        for (const prom of deleteRequestPromises) {
+            const request = await prom;
+            expect(request.method()).toBe("PUT");
+            expect(request.postData()).toBe(JSON.stringify({}));
+        }
+    });
 });

res/css/_components.pcss

@@ -48,6 +48,7 @@
 @import "./components/views/settings/devices/_FilteredDeviceListHeader.pcss";
 @import "./components/views/settings/devices/_SecurityRecommendations.pcss";
 @import "./components/views/settings/devices/_SelectableDeviceTile.pcss";
+@import "./components/views/settings/encryption/_KeyStoragePanel.pcss";
 @import "./components/views/settings/shared/_SettingsSubsection.pcss";
 @import "./components/views/settings/shared/_SettingsSubsectionHeading.pcss";
 @import "./components/views/spaces/_QuickThemeSwitcher.pcss";

res/css/components/views/settings/encryption/_KeyStoragePanel.pcss

@@ -0,0 +1,10 @@
+/*
+ * Copyright 2025 New Vector Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+.mx_KeyStoragePanel_toggleRow {
+    flex-direction: row;
+}

src/DeviceListener.ts

@@ -49,10 +49,13 @@ import { asyncSomeParallel } from "./utils/arrays.ts";
 
 const KEY_BACKUP_POLL_INTERVAL = 5 * 60 * 1000;
 
-// Unfortunately named account data key used by Element X to indicate that the user
-// has chosen to disable server side key backups. We need to set and honour this
-// to prevent Element X from automatically turning key backup back on.
-const BACKUP_DISABLED_ACCOUNT_DATA_KEY = "m.org.matrix.custom.backup_disabled";
+/**
+ * Unfortunately-named account data key used by Element X to indicate that the user
+ * has chosen to disable server side key backups.
+ *
+ * We need to set and honour this to prevent Element X from automatically turning key backup back on.
+ */
+export const BACKUP_DISABLED_ACCOUNT_DATA_KEY = "m.org.matrix.custom.backup_disabled";
 
 const logger = baseLogger.getChild("DeviceListener:");
 

src/components/viewmodels/settings/encryption/KeyStoragePanelViewModel.ts

@@ -0,0 +1,116 @@
+/*
+Copyright 2025 New Vector Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE files in the repository root for full details.
+*/
+
+import { useCallback, useEffect, useState } from "react";
+import { logger } from "matrix-js-sdk/src/logger";
+
+import { useMatrixClientContext } from "../../../../contexts/MatrixClientContext";
+import DeviceListener, { BACKUP_DISABLED_ACCOUNT_DATA_KEY } from "../../../../DeviceListener";
+
+interface KeyStoragePanelState {
+    /**
+     * Whether the app's "key storage" option should show as enabled to the user,
+     * or 'undefined' if the state is still loading.
+     */
+    isEnabled: boolean | undefined;
+
+    /**
+     * A function that can be called to enable or disable key storage.
+     * @param enable True to turn key storage on or false to turn it off
+     */
+    setEnabled: (enable: boolean) => void;
+
+    /**
+     * True if the state is still loading for the first time
+     */
+    loading: boolean;
+
+    /**
+     * True if the status is in the process of being changed
+     */
+    busy: boolean;
+}
+
+/** Returns a ViewModel for use in {@link KeyStoragePanel} and {@link DeleteKeyStoragePanel}. */
+export function useKeyStoragePanelViewModel(): KeyStoragePanelState {
+    const [isEnabled, setIsEnabled] = useState<boolean | undefined>(undefined);
+    const [loading, setLoading] = useState(true);
+    // Whilst the change is being made, the toggle will reflect the pending value rather than the actual state
+    const [pendingValue, setPendingValue] = useState<boolean | undefined>(undefined);
+
+    const matrixClient = useMatrixClientContext();
+
+    const checkStatus = useCallback(async () => {
+        const crypto = matrixClient.getCrypto();
+        if (!crypto) {
+            logger.error("Can't check key backup status: no crypto module available");
+            return;
+        }
+        // The toggle is enabled only if this device will upload megolm keys to the backup.
+        // This is consistent with EX.
+        const activeBackupVersion = await crypto.getActiveSessionBackupVersion();
+        setIsEnabled(activeBackupVersion !== null);
+    }, [matrixClient]);
+
+    useEffect(() => {
+        (async () => {
+            await checkStatus();
+            setLoading(false);
+        })();
+    }, [checkStatus]);
+
+    const setEnabled = useCallback(
+        async (enable: boolean) => {
+            setPendingValue(enable);
+            try {
+                // stop the device listener since enabling or (especially) disabling key storage must be
+                // done with a sequence of API calls that will put the account in a slightly different
+                // state each time, so suppress any warning toasts until the process is finished (when
+                // we'll turn it back on again.)
+                DeviceListener.sharedInstance().stop();
+
+                const crypto = matrixClient.getCrypto();
+                if (!crypto) {
+                    logger.error("Can't change key backup status: no crypto module available");
+                    return;
+                }
+                if (enable) {
+                    // If there is no existing key backup on the server, create one.
+                    // `resetKeyBackup` will delete any existing backup, so we only do this if there is no existing backup.
+                    const currentKeyBackup = await crypto.checkKeyBackupAndEnable();
+                    if (currentKeyBackup === null) {
+                        await crypto.resetKeyBackup();
+
+                        // resetKeyBackup fires this off in the background without waiting, so we need to do it
+                        // explicitly and wait for it, otherwise it won't be enabled yet when we check again.
+                        await crypto.checkKeyBackupAndEnable();
+                    }
+
+                    // Set the flag so that EX no longer thinks the user wants backup disabled
+                    await matrixClient.setAccountData(BACKUP_DISABLED_ACCOUNT_DATA_KEY, { disabled: false });
+                } else {
+                    // This method will delete the key backup as well as server side recovery keys and other
+                    // server-side crypto data.
+                    await crypto.disableKeyStorage();
+
+                    // Set a flag to say that the user doesn't want key backup.
+                    // Element X uses this to determine whether to set up automatically,
+                    // so this will stop EX turning it back on spontaneously.
+                    await matrixClient.setAccountData(BACKUP_DISABLED_ACCOUNT_DATA_KEY, { disabled: true });
+                }
+
+                await checkStatus();
+            } finally {
+                setPendingValue(undefined);
+                DeviceListener.sharedInstance().start(matrixClient);
+            }
+        },
+        [setPendingValue, checkStatus, matrixClient],
+    );
+
+    return { isEnabled: pendingValue ?? isEnabled, setEnabled, loading, busy: pendingValue !== undefined };
+}

src/components/views/settings/encryption/DeleteKeyStoragePanel.tsx

@@ -0,0 +1,79 @@
+/*
+ * Copyright 2025 New Vector Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+import { Breadcrumb, Button, VisualList, VisualListItem } from "@vector-im/compound-web";
+import CrossIcon from "@vector-im/compound-design-tokens/assets/web/icons/close";
+import ErrorIcon from "@vector-im/compound-design-tokens/assets/web/icons/error-solid";
+import React, { useCallback, useState } from "react";
+
+import { _t } from "../../../../languageHandler";
+import { EncryptionCard } from "./EncryptionCard";
+import { useKeyStoragePanelViewModel } from "../../../viewmodels/settings/encryption/KeyStoragePanelViewModel";
+import SdkConfig from "../../../../SdkConfig";
+import { EncryptionCardButtons } from "./EncryptionCardButtons";
+import { EncryptionCardEmphasisedContent } from "./EncryptionCardEmphasisedContent";
+
+interface Props {
+    /**
+     * Called when the user either cancels the operation or key storage has been disabled
+     */
+    onFinish: () => void;
+}
+
+/**
+ * Confirms that the user really wants to turn off and delete their key storage.  Part of the "Encryption" settings tab.
+ */
+export function DeleteKeyStoragePanel({ onFinish }: Props): JSX.Element {
+    const { setEnabled } = useKeyStoragePanelViewModel();
+    const [busy, setBusy] = useState(false);
+
+    const onDeleteClick = useCallback(async () => {
+        setBusy(true);
+        try {
+            await setEnabled(false);
+        } finally {
+            setBusy(false);
+        }
+        onFinish();
+    }, [setEnabled, onFinish]);
+
+    return (
+        <>
+            <Breadcrumb
+                backLabel={_t("action|back")}
+                onBackClick={onFinish}
+                pages={[_t("settings|encryption|title"), _t("settings|encryption|delete_key_storage|breadcrumb_page")]}
+                onPageClick={onFinish}
+            />
+            <EncryptionCard
+                Icon={ErrorIcon}
+                destructive={true}
+                title={_t("settings|encryption|delete_key_storage|title")}
+            >
+                <EncryptionCardEmphasisedContent>
+                    {_t("settings|encryption|delete_key_storage|description")}
+                    <VisualList>
+                        <VisualListItem Icon={CrossIcon} destructive={true}>
+                            {_t("settings|encryption|delete_key_storage|list_first")}
+                        </VisualListItem>
+                        <VisualListItem Icon={CrossIcon} destructive={true}>
+                            {_t("settings|encryption|delete_key_storage|list_second", { brand: SdkConfig.get().brand })}
+                        </VisualListItem>
+                    </VisualList>
+                </EncryptionCardEmphasisedContent>
+                <EncryptionCardButtons>
+                    <Button destructive={true} onClick={onDeleteClick} disabled={busy}>
+                        {_t("settings|encryption|delete_key_storage|confirm")}
+                    </Button>
+                    <Button kind="tertiary" onClick={onFinish}>
+                        {_t("action|cancel")}
+                    </Button>
+                </EncryptionCardButtons>
+            </EncryptionCard>
+        </>
+    );
+}

src/components/views/settings/encryption/KeyStoragePanel.tsx

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2025 New Vector Ltd.
+ *
+ * SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+ * Please see LICENSE files in the repository root for full details.
+ */
+
+import React, { useCallback } from "react";
+import { InlineField, InlineSpinner, Label, Root, ToggleControl } from "@vector-im/compound-web";
+
+import type { FormEvent } from "react";
+import { SettingsSection } from "../shared/SettingsSection";
+import { _t } from "../../../../languageHandler";
+import { SettingsHeader } from "../SettingsHeader";
+import { useKeyStoragePanelViewModel } from "../../../viewmodels/settings/encryption/KeyStoragePanelViewModel";
+
+interface Props {
+    /**
+     * Called when the user turns off the "allow key storage" toggle
+     */
+    onKeyStorageDisableClick: () => void;
+}
+
+/**
+ * This component allows the user to set up or change their recovery key.
+ *
+ * It is used within the "Encryption" settings tab.
+ */
+export const KeyStoragePanel: React.FC<Props> = ({ onKeyStorageDisableClick }) => {
+    const { isEnabled, setEnabled, loading, busy } = useKeyStoragePanelViewModel();
+
+    const onKeyBackupChange = useCallback(
+        (e: FormEvent<HTMLInputElement>) => {
+            if (e.currentTarget.checked) {
+                setEnabled(true);
+            } else {
+                onKeyStorageDisableClick();
+            }
+        },
+        [setEnabled, onKeyStorageDisableClick],
+    );
+
+    if (loading) {
+        return <InlineSpinner aria-label={_t("common|loading")} />;
+    }
+
+    return (
+        <SettingsSection
+            legacy={false}
+            heading={
+                <SettingsHeader
+                    hasRecommendedTag={isEnabled === false}
+                    label={_t("settings|encryption|key_storage|title")}
+                />
+            }
+            subHeading={_t("settings|encryption|key_storage|description", undefined, {
+                a: (sub) => (
+                    <a href="https://element.io/help#encryption5" target="_blank" rel="noreferrer noopener">
+                        {sub}
+                    </a>
+                ),
+            })}
+        >
+            <Root className="mx_KeyStoragePanel_toggleRow">
+                <InlineField
+                    name="keyStorage"
+                    control={<ToggleControl name="keyStorage" checked={isEnabled} onChange={onKeyBackupChange} />}
+                >
+                    <Label>{_t("settings|encryption|key_storage|allow_key_storage")}</Label>
+                </InlineField>
+                {busy && <InlineSpinner />}
+            </Root>
+        </SettingsSection>
+    );
+};