Negotiate E2E by default for DMs (#907)

CHANGES.md

@@ -3,6 +3,7 @@ Changes in RiotX 0.14.0 (2020-XX-XX)
 
 Features ✨:
  - Enable encryption in unencrypted rooms, from the room settings (#212)
+ - Negotiate E2E by default for DMs (#907)
 
 Improvements 🙌:
  - Sharing things to RiotX: sort list by recent room first (#771)

matrix-sdk-android/src/main/java/im/vector/matrix/android/api/extensions/Booleans.kt

@@ -0,0 +1,22 @@
+/*
+ * Copyright 2020 New Vector Ltd
+ *
+ * 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.
+ */
+
+package im.vector.matrix.android.api.extensions
+
+fun Boolean?.orTrue() = this ?: true
+
+fun Boolean?.orFalse() = this ?: false
+

matrix-sdk-android/src/main/java/im/vector/matrix/android/api/session/room/model/create/CreateRoomParams.kt

@@ -120,12 +120,19 @@ data class CreateRoomParams(
         @Json(name = "power_level_content_override")
         val powerLevelContentOverride: PowerLevelsContent? = null
 ) {
+    /**
+     * Set to true means that if cross-signing is enabled and we can get keys for every invited users,
+     * the encryption will be enabled on the created room
+     */
+    @Transient
+    var enableEncryptionIfInvitedUsersSupportIt: Boolean = false
+
     /**
      * Add the crypto algorithm to the room creation parameters.
      *
      * @param algorithm the algorithm
      */
-    fun enableEncryptionWithAlgorithm(algorithm: String): CreateRoomParams {
+    fun enableEncryptionWithAlgorithm(algorithm: String = MXCRYPTO_ALGORITHM_MEGOLM): CreateRoomParams {
         return if (algorithm == MXCRYPTO_ALGORITHM_MEGOLM) {
             val contentMap = mapOf("algorithm" to algorithm)
 

matrix-sdk-android/src/main/java/im/vector/matrix/android/internal/session/room/create/CreateRoomTask.kt

@@ -17,9 +17,12 @@
 package im.vector.matrix.android.internal.session.room.create
 
 import com.zhuinden.monarchy.Monarchy
+import im.vector.matrix.android.api.extensions.orTrue
+import im.vector.matrix.android.api.session.crypto.crosssigning.CrossSigningService
 import im.vector.matrix.android.api.session.room.failure.CreateRoomFailure
 import im.vector.matrix.android.api.session.room.model.create.CreateRoomParams
 import im.vector.matrix.android.api.session.room.model.create.CreateRoomResponse
+import im.vector.matrix.android.internal.crypto.DeviceListManager
 import im.vector.matrix.android.internal.database.awaitNotEmptyResult
 import im.vector.matrix.android.internal.database.model.RoomEntity
 import im.vector.matrix.android.internal.database.model.RoomEntityFields
@@ -49,12 +52,41 @@ internal class DefaultCreateRoomTask @Inject constructor(
         private val readMarkersTask: SetReadMarkersTask,
         @SessionDatabase
         private val realmConfiguration: RealmConfiguration,
+        private val crossSigningService: CrossSigningService,
+        private val deviceListManager: DeviceListManager,
         private val eventBus: EventBus
 ) : CreateRoomTask {
 
     override suspend fun execute(params: CreateRoomParams): String {
+        val createRoomParams = params
+                .takeIf { it.enableEncryptionIfInvitedUsersSupportIt }
+                .takeIf { crossSigningService.isCrossSigningEnabled() }
+                ?.takeIf { it.invite3pids.isNullOrEmpty() }
+                ?.invitedUserIds
+                ?.let { userIds ->
+                    val keys = deviceListManager.downloadKeys(userIds, forceDownload = false)
+
+                    userIds.any { userId ->
+                        if (keys.map[userId].isNullOrEmpty()) {
+                            // A user has no device, so do not enable encryption
+                            true
+                        } else {
+                            // Check that every user's device have at least one key
+                            keys.map[userId]?.values?.any { it.keys.isNullOrEmpty() } ?: true
+                        }
+                    }
+                }
+                .orTrue()
+                .let { cannotEnableEncryption ->
+                    if (!cannotEnableEncryption) {
+                        params.enableEncryptionWithAlgorithm()
+                    } else {
+                        params
+                    }
+                }
+
         val createRoomResponse = executeRequest<CreateRoomResponse>(eventBus) {
-            apiCall = roomAPI.createRoom(params)
+            apiCall = roomAPI.createRoom(createRoomParams)
         }
         val roomId = createRoomResponse.roomId!!
         // Wait for room to come back from the sync (but it can maybe be in the DB if the sync response is received before)
@@ -66,8 +98,8 @@ internal class DefaultCreateRoomTask @Inject constructor(
         } catch (exception: TimeoutCancellationException) {
             throw CreateRoomFailure.CreatedWithTimeout
         }
-        if (params.isDirect()) {
-            handleDirectChatCreation(params, roomId)
+        if (createRoomParams.isDirect()) {
+            handleDirectChatCreation(createRoomParams, roomId)
         }
         setReadMarkers(roomId)
         return roomId

vector/src/main/java/im/vector/riotx/features/createdirect/CreateDirectRoomViewModel.kt

@@ -92,14 +92,12 @@ class CreateDirectRoomViewModel @AssistedInject constructor(@Assisted
     }
 
     private fun createRoomAndInviteSelectedUsers() = withState { currentState ->
-        val isDirect = currentState.selectedUsers.size == 1
         val roomParams = CreateRoomParams(
-                invitedUserIds = ArrayList(currentState.selectedUsers.map { it.userId })
-        ).apply {
-            if (isDirect) {
-                setDirectMessage()
-            }
-        }
+                invitedUserIds = currentState.selectedUsers.map { it.userId }
+        )
+                .setDirectMessage()
+                .also { it.enableEncryptionIfInvitedUsersSupportIt = true }
+
         session.rx()
                 .createRoom(roomParams)
                 .execute {

vector/src/main/java/im/vector/riotx/features/crypto/verification/VerificationBottomSheetViewModel.kt

@@ -128,9 +128,11 @@ class VerificationBottomSheetViewModel @AssistedInject constructor(@Assisted ini
                         )
                     }
                     val roomParams = CreateRoomParams(
-                            invitedUserIds = listOf(otherUserId).toMutableList()
+                            invitedUserIds = listOf(otherUserId)
                     )
                             .setDirectMessage()
+                            .also { it.enableEncryptionIfInvitedUsersSupportIt = true }
+
                     session.createRoom(roomParams, object : MatrixCallback<String> {
                         override fun onSuccess(data: String) {
                             setState {