Merge branch 'develop' into florianduros/tooltip-update

src/utils/device/dehydration.ts

@@ -0,0 +1,57 @@
+/*
+Copyright 2024 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import { logger } from "matrix-js-sdk/src/logger";
+import { CryptoApi } from "matrix-js-sdk/src/matrix";
+
+import { MatrixClientPeg } from "../../MatrixClientPeg";
+
+/**
+ * Check if device dehydration is enabled.
+ *
+ * Note that this doesn't necessarily mean that device dehydration has been initialised
+ * (yet) on this client; rather, it means that the server supports it, the crypto backend
+ * supports it, and the application configuration suggests that it *should* be
+ * initialised on this device.
+ *
+ * Dehydration can currently only be enabled by setting a flag in the .well-known file.
+ */
+async function deviceDehydrationEnabled(crypto: CryptoApi | undefined): Promise<boolean> {
+    if (!crypto) {
+        return false;
+    }
+    if (!(await crypto.isDehydrationSupported())) {
+        return false;
+    }
+    const wellknown = await MatrixClientPeg.safeGet().waitForClientWellKnown();
+    return !!wellknown?.["org.matrix.msc3814"];
+}
+
+/**
+ * If dehydration is enabled (i.e., it is supported by the server and enabled in
+ * the configuration), 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 initialiseDehydration(createNewKey: boolean = false): Promise<void> {
+    const crypto = MatrixClientPeg.safeGet().getCrypto();
+    if (await deviceDehydrationEnabled(crypto)) {
+        logger.log("Device dehydration enabled");
+        await crypto!.startDehydration(createNewKey);
+    }
+}