From 1c2e05e925529afe71910fa43cc6257c15f6cd03 Mon Sep 17 00:00:00 2001
From: Hubert Chathi <hubert@uhoreg.ca>
Date: Mon, 31 Aug 2020 14:40:16 -0400
Subject: [PATCH] initial version of device rehydration support

---
 src/CrossSigningManager.js |  2 +-
 src/Login.js               | 60 +++++++++++++++++++++++++++++++++++++-
 src/MatrixClientPeg.ts     | 28 ++++++++++++++++--
 3 files changed, 85 insertions(+), 5 deletions(-)

diff --git a/src/CrossSigningManager.js b/src/CrossSigningManager.js
index 676c41d7d7..43d089010c 100644
--- a/src/CrossSigningManager.js
+++ b/src/CrossSigningManager.js
@@ -40,7 +40,7 @@ export class AccessCancelledError extends Error {
     }
 }
 
-async function confirmToDismiss() {
+export async function confirmToDismiss() {
     const QuestionDialog = sdk.getComponent("dialogs.QuestionDialog");
     const [sure] = await Modal.createDialog(QuestionDialog, {
         title: _t("Cancel entering passphrase?"),
diff --git a/src/Login.js b/src/Login.js
index 04805b4af9..4e46fc3665 100644
--- a/src/Login.js
+++ b/src/Login.js
@@ -18,7 +18,12 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+import Modal from './Modal';
+import * as sdk from './index';
+import { AccessCancelledError, confirmToDismiss } from "./CrossSigningManager";
 import Matrix from "matrix-js-sdk";
+import { deriveKey } from 'matrix-js-sdk/src/crypto/key_passphrase';
+import { decodeRecoveryKey } from 'matrix-js-sdk/src/crypto/recoverykey';
 
 export default class Login {
     constructor(hsUrl, isUrl, fallbackHsUrl, opts) {
@@ -159,12 +164,18 @@ export default class Login {
  * @returns {MatrixClientCreds}
  */
 export async function sendLoginRequest(hsUrl, isUrl, loginType, loginParams) {
+    let rehydrationKeyInfo;
+    let rehydrationKey;
+
     const client = Matrix.createClient({
         baseUrl: hsUrl,
         idBaseUrl: isUrl,
+        cryptoCallbacks: {
+            getDehydrationKey
+        }
     });
 
-    const data = await client.login(loginType, loginParams);
+    const data = await client.loginWithRehydration(null, loginType, loginParams);
 
     const wellknown = data.well_known;
     if (wellknown) {
@@ -185,5 +196,52 @@ export async function sendLoginRequest(hsUrl, isUrl, loginType, loginParams) {
         userId: data.user_id,
         deviceId: data.device_id,
         accessToken: data.access_token,
+        rehydrationKeyInfo,
+        rehydrationKey,
+        olmAccount: data._olm_account,
     };
 }
+
+async function getDehydrationKey(keyInfo) {
+    const inputToKey = async ({ passphrase, recoveryKey }) => {
+        if (passphrase) {
+            return deriveKey(
+                passphrase,
+                keyInfo.passphrase.salt,
+                keyInfo.passphrase.iterations,
+            );
+        } else {
+            return decodeRecoveryKey(recoveryKey);
+        }
+    };
+    const AccessSecretStorageDialog =
+        sdk.getComponent("dialogs.secretstorage.AccessSecretStorageDialog");
+    const { finished } = Modal.createTrackedDialog("Access Secret Storage dialog", "",
+        AccessSecretStorageDialog,
+        /* props= */
+        {
+            keyInfo,
+            checkPrivateKey: async (input) => {
+                // FIXME:
+                return true;
+            },
+        },
+        /* className= */ null,
+        /* isPriorityModal= */ false,
+        /* isStaticModal= */ false,
+        /* options= */ {
+            onBeforeClose: async (reason) => {
+                if (reason === "backgroundClick") {
+                    return confirmToDismiss();
+                }
+                return true;
+            },
+        },
+    );
+    const [input] = await finished;
+    if (!input) {
+        throw new AccessCancelledError();
+    }
+    const key = await inputToKey(input);
+    return key;
+}
diff --git a/src/MatrixClientPeg.ts b/src/MatrixClientPeg.ts
index be16f5fe10..61b7a04069 100644
--- a/src/MatrixClientPeg.ts
+++ b/src/MatrixClientPeg.ts
@@ -42,6 +42,9 @@ export interface IMatrixClientCreds {
     accessToken: string;
     guest: boolean;
     pickleKey?: string;
+    rehydrationKey?: Uint8Array;
+    rehydrationKeyInfo?: {[props: string]: any};
+    olmAccount?: any;
 }
 
 // TODO: Move this to the js-sdk
@@ -248,12 +251,10 @@ class _MatrixClientPeg implements IMatrixClientPeg {
 
     private createClient(creds: IMatrixClientCreds): void {
         // TODO: Make these opts typesafe with the js-sdk
-        const opts = {
+        const opts: any = {
             baseUrl: creds.homeserverUrl,
             idBaseUrl: creds.identityServerUrl,
             accessToken: creds.accessToken,
-            userId: creds.userId,
-            deviceId: creds.deviceId,
             pickleKey: creds.pickleKey,
             timelineSupport: true,
             forceTURN: !SettingsStore.getValue('webRtcAllowPeerToPeer'),
@@ -268,6 +269,23 @@ class _MatrixClientPeg implements IMatrixClientPeg {
             cryptoCallbacks: {},
         };
 
+        if (creds.olmAccount) {
+            opts.deviceToImport = {
+                olmDevice: {
+                    pickledAccount: creds.olmAccount.pickle("DEFAULT_KEY"),
+                    sessions: [],
+                    pickleKey: "DEFAULT_KEY",
+                },
+                userId: creds.userId,
+                deviceId: creds.deviceId,
+            };
+        } else {
+            opts.userId = creds.userId;
+            opts.deviceId = creds.deviceId;
+        }
+
+        // FIXME: modify crossSigningCallbacks.getSecretStorageKey so that it tries using rehydrationkey and/or saves the passphrase info
+
         // These are always installed regardless of the labs flag so that
         // cross-signing features can toggle on without reloading and also be
         // accessed immediately after login.
@@ -275,6 +293,10 @@ class _MatrixClientPeg implements IMatrixClientPeg {
 
         this.matrixClient = createMatrixClient(opts);
 
+        if (creds.rehydrationKey) {
+            this.matrixClient.cacheDehydrationKey(creds.rehydrationKey, creds.rehydrationKeyInfo || {});
+        }
+
         // we're going to add eventlisteners for each matrix event tile, so the
         // potential number of event listeners is quite high.
         this.matrixClient.setMaxListeners(500);