Fix / reset cross signing not well supported

2024-07-24 03:26:53 +00:00 · 2020-10-12 17:03:28 +02:00 · 2020-10-12 17:03:28 +02:00 · 840c8e0b91
parent 40aa012588
commit 840c8e0b91
7 changed files with 88 additions and 7 deletions
--- a/CHANGES.md
+++ b/CHANGES.md
@ -26,6 +26,7 @@ Bugfix 🐛:
 - Invalid popup when pressing back (#1635)
 - Simplifies draft management and should fix bunch of draft issues (#952, #683)
 - Very long topic cannot be fully visible (#1957)
+ - Properly detect cross signing keys reset

 Translations 🗣:
 -
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/DeviceListManager.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/DeviceListManager.kt
@ -359,7 +359,6 @@ internal class DeviceListManager @Inject constructor(private val cryptoStore: IM
                cryptoStore.storeUserDevices(userId, workingCopy)
            }

-            // Handle cross signing keys update
            val masterKey = response.masterKeys?.get(userId)?.toCryptoModel().also {
                Timber.v("## CRYPTO | CrossSigning : Got keys for $userId : MSK ${it?.unpaddedBase64PublicKey}")
            }
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/store/db/RealmCryptoStore.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/crypto/store/db/RealmCryptoStore.kt
@ -302,22 +302,42 @@ internal class RealmCryptoStore @Inject constructor(
                            userEntity.crossSigningInfoEntity?.deleteFromRealm()
                            userEntity.crossSigningInfoEntity = null
                        } else {
+                            var shouldResetMyDevicesLocalTrust = false
                            CrossSigningInfoEntity.getOrCreate(realm, userId).let { signingInfo ->
                                // What should we do if we detect a change of the keys?
                                val existingMaster = signingInfo.getMasterKey()
                                if (existingMaster != null && existingMaster.publicKeyBase64 == masterKey.unpaddedBase64PublicKey) {
                                    crossSigningKeysMapper.update(existingMaster, masterKey)
                                } else {
+                                    Timber.d("## CrossSigning  MSK change for $userId")
                                    val keyEntity = crossSigningKeysMapper.map(masterKey)
                                    signingInfo.setMasterKey(keyEntity)
+                                    if (userId == credentials.userId) {
+                                        shouldResetMyDevicesLocalTrust = true
+                                        // my msk has changed! clear my private key
+                                        // Could we have some race here? e.g I am the one that did change the keys
+                                        // could i get this update to early and clear the private keys?
+                                        // -> initializeCrossSigning is guarding for that by storing all at once
+                                        realm.where<CryptoMetadataEntity>().findFirst()?.apply {
+                                            xSignMasterPrivateKey = null
+                                        }
+                                    }
                                }

                                val existingSelfSigned = signingInfo.getSelfSignedKey()
                                if (existingSelfSigned != null && existingSelfSigned.publicKeyBase64 == selfSigningKey.unpaddedBase64PublicKey) {
                                    crossSigningKeysMapper.update(existingSelfSigned, selfSigningKey)
                                } else {
+                                    Timber.d("## CrossSigning  SSK change for $userId")
                                    val keyEntity = crossSigningKeysMapper.map(selfSigningKey)
                                    signingInfo.setSelfSignedKey(keyEntity)
+                                    if (userId == credentials.userId) {
+                                        shouldResetMyDevicesLocalTrust = true
+                                        // my ssk has changed! clear my private key
+                                        realm.where<CryptoMetadataEntity>().findFirst()?.apply {
+                                            xSignSelfSignedPrivateKey = null
+                                        }
+                                    }
                                }

                                // Only for me
@ -326,10 +346,29 @@ internal class RealmCryptoStore @Inject constructor(
                                    if (existingUSK != null && existingUSK.publicKeyBase64 == userSigningKey.unpaddedBase64PublicKey) {
                                        crossSigningKeysMapper.update(existingUSK, userSigningKey)
                                    } else {
+                                        Timber.d("## CrossSigning  USK change for $userId")
                                        val keyEntity = crossSigningKeysMapper.map(userSigningKey)
                                        signingInfo.setUserSignedKey(keyEntity)
+                                        if (userId == credentials.userId) {
+                                            shouldResetMyDevicesLocalTrust = true
+                                            // my usk has changed! clear my private key
+                                            realm.where<CryptoMetadataEntity>().findFirst()?.apply {
+                                                xSignUserPrivateKey = null
+                                            }
+                                        }
                                    }
                                }
+
+                                // When my cross signing keys are reset, we consider clearing all existing device trust
+                                if (shouldResetMyDevicesLocalTrust) {
+                                    realm.where<UserEntity>()
+                                            .equalTo(UserEntityFields.USER_ID, credentials.userId)
+                                            .findFirst()
+                                            ?.devices?.forEach {
+                                                it?.trustLevelEntity?.crossSignedVerified = false
+                                                it?.trustLevelEntity?.locallyVerified = it.deviceId == credentials.deviceId
+                                            }
+                                }
                                userEntity.crossSigningInfoEntity = signingInfo
                            }
                        }
@ -1197,7 +1236,7 @@ internal class RealmCryptoStore @Inject constructor(
                    .findAll()
                    .mapNotNull { entity ->
                        when (entity.type) {
-                            GossipRequestType.KEY -> {
+                            GossipRequestType.KEY    -> {
                                IncomingRoomKeyRequest(
                                        userId = entity.otherUserId,
                                        deviceId = entity.otherDeviceId,
--- a/vector/src/main/java/im/vector/app/features/home/HomeActivity.kt
+++ b/vector/src/main/java/im/vector/app/features/home/HomeActivity.kt
@ -138,6 +138,7 @@ class HomeActivity : VectorBaseActivity(), ToolbarConfigurable, UnknownDeviceDet
                is HomeActivityViewEvents.AskPasswordToInitCrossSigning -> handleAskPasswordToInitCrossSigning(it)
                is HomeActivityViewEvents.OnNewSession                  -> handleOnNewSession(it)
                HomeActivityViewEvents.PromptToEnableSessionPush        -> handlePromptToEnablePush()
+                is HomeActivityViewEvents.OnCrossSignedInvalidated      -> handleCrossSigningInvalidated(it)
            }.exhaustive
        }
        homeActivityViewModel.subscribe(this) { renderState(it) }
@ -182,6 +183,17 @@ class HomeActivity : VectorBaseActivity(), ToolbarConfigurable, UnknownDeviceDet
        }
    }

+    private fun handleCrossSigningInvalidated(event: HomeActivityViewEvents.OnCrossSignedInvalidated) {
+        // We need to ask
+        promptSecurityEvent(
+                event.userItem,
+                R.string.crosssigning_verify_this_session,
+                R.string.confirm_your_identity
+        ) {
+            it.navigator.waitSessionVerification(it)
+        }
+    }
+
    private fun handleOnNewSession(event: HomeActivityViewEvents.OnNewSession) {
        // We need to ask
        promptSecurityEvent(
--- a/vector/src/main/java/im/vector/app/features/home/HomeActivityViewEvents.kt
+++ b/vector/src/main/java/im/vector/app/features/home/HomeActivityViewEvents.kt
@ -22,5 +22,6 @@ import org.matrix.android.sdk.api.util.MatrixItem
 sealed class HomeActivityViewEvents : VectorViewEvents {
    data class AskPasswordToInitCrossSigning(val userItem: MatrixItem.UserItem?) : HomeActivityViewEvents()
    data class OnNewSession(val userItem: MatrixItem.UserItem?, val waitForIncomingRequest: Boolean = true) : HomeActivityViewEvents()
+    data class OnCrossSignedInvalidated(val userItem: MatrixItem.UserItem?) : HomeActivityViewEvents()
    object PromptToEnableSessionPush : HomeActivityViewEvents()
 }
--- a/vector/src/main/java/im/vector/app/features/home/HomeActivityViewModel.kt
+++ b/vector/src/main/java/im/vector/app/features/home/HomeActivityViewModel.kt
@ -27,6 +27,9 @@ import im.vector.app.core.extensions.exhaustive
 import im.vector.app.core.platform.VectorViewModel
 import im.vector.app.features.login.ReAuthHelper
 import im.vector.app.features.settings.VectorPreferences
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.delay
+import kotlinx.coroutines.launch
 import org.matrix.android.sdk.api.MatrixCallback
 import org.matrix.android.sdk.api.NoOpMatrixCallback
 import org.matrix.android.sdk.api.pushrules.RuleIds
@ -38,9 +41,7 @@ import org.matrix.android.sdk.internal.crypto.model.CryptoDeviceInfo
 import org.matrix.android.sdk.internal.crypto.model.MXUsersDevicesMap
 import org.matrix.android.sdk.internal.crypto.model.rest.UserPasswordAuth
 import org.matrix.android.sdk.rx.asObservable
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.delay
-import kotlinx.coroutines.launch
+import org.matrix.android.sdk.rx.rx
 import timber.log.Timber

 class HomeActivityViewModel @AssistedInject constructor(
@ -67,11 +68,39 @@ class HomeActivityViewModel @AssistedInject constructor(
    }

    private var checkBootstrap = false
+    private var onceTrusted = false

    init {
        observeInitialSync()
        mayBeInitializeCrossSigning()
        checkSessionPushIsOn()
+        observeCrossSigningReset()
+    }
+
+    private fun observeCrossSigningReset() {
+        val safeActiveSession = activeSessionHolder.getSafeActiveSession()
+        val crossSigningService = safeActiveSession
+                ?.cryptoService()
+                ?.crossSigningService()
+        onceTrusted = crossSigningService
+                ?.allPrivateKeysKnown() ?: false
+
+        safeActiveSession
+                ?.rx()
+                ?.liveCrossSigningInfo(safeActiveSession.myUserId)
+                ?.subscribe {
+                    val isVerified = it.getOrNull()?.isTrusted() ?: false
+                    if (!isVerified && onceTrusted) {
+                        // cross signing keys have been reset
+                        // Tigger a popup to re-verify
+                        _viewEvents.post(
+                                HomeActivityViewEvents.OnCrossSignedInvalidated(
+                                        safeActiveSession.getUser(safeActiveSession.myUserId)?.toMatrixItem()
+                                )
+                        )
+                    }
+                    onceTrusted = isVerified
+                }?.disposeOnClear()
    }

    private fun observeInitialSync() {
--- a/vector/src/main/java/im/vector/app/features/home/UnknownDeviceDetectorSharedViewModel.kt
+++ b/vector/src/main/java/im/vector/app/features/home/UnknownDeviceDetectorSharedViewModel.kt
@ -30,6 +30,8 @@ import im.vector.app.core.platform.EmptyViewEvents
 import im.vector.app.core.platform.VectorViewModel
 import im.vector.app.core.platform.VectorViewModelAction
 import im.vector.app.features.settings.VectorPreferences
+import io.reactivex.Observable
+import io.reactivex.functions.Function3
 import org.matrix.android.sdk.api.NoOpMatrixCallback
 import org.matrix.android.sdk.api.extensions.orFalse
 import org.matrix.android.sdk.api.session.Session
@ -39,8 +41,6 @@ import org.matrix.android.sdk.api.util.toMatrixItem
 import org.matrix.android.sdk.internal.crypto.model.CryptoDeviceInfo
 import org.matrix.android.sdk.internal.crypto.model.rest.DeviceInfo
 import org.matrix.android.sdk.internal.crypto.store.PrivateKeysInfo
-import io.reactivex.Observable
-import io.reactivex.functions.Function3
 import org.matrix.android.sdk.rx.rx
 import timber.log.Timber
 import java.util.concurrent.TimeUnit