Implement logic for sign in with QR

changelog.d/7369.feature

@@ -0,0 +1 @@
+Add logic for sign in with QR code

library/ui-strings/src/main/res/values/strings.xml

@@ -3382,9 +3382,16 @@
     <string name="qr_code_login_header_failed_device_is_not_supported_description">Linking with this device is not supported.</string>
     <string name="qr_code_login_header_failed_timeout_description">The linking wasn’t completed in the required time.</string>
     <string name="qr_code_login_header_failed_denied_description">The request was denied on the other device.</string>
-    <string name="qr_code_login_new_device_instruction_1">Open ${app_name} on your other device</string>
-    <string name="qr_code_login_new_device_instruction_2">Go to Settings -> Security &amp; Privacy -> Show All Sessions</string>
-    <string name="qr_code_login_new_device_instruction_3">Select \'Show QR code in this device\'</string>
+    <string name="qr_code_login_header_failed_other_description">The request failed.</string>
+    <string name="qr_code_login_header_failed_e2ee_security_issue_description">A security issue was encountered setting up secure messaging. One of the following may be compromised: Your homeserver; Your intent connection(s); Your device(s);</string>
+    <string name="qr_code_login_header_failed_other_device_already_signed_in_description">The other device is already signed in.</string>
+    <string name="qr_code_login_header_failed_other_device_not_signed_in_description">The other device must be signed in.</string>
+    <string name="qr_code_login_header_failed_invalid_qr_code_description">That QR code is invalid.</string>
+    <string name="qr_code_login_header_failed_user_cancelled_description">The sign in was cancelled on the other device.</string>
+    <string name="qr_code_login_header_failed_homeserver_is_not_supported_description">The homeserver doesn\'t support sign in with QR code.</string>
+    <string name="qr_code_login_new_device_instruction_1">Open the app on your other device</string>
+    <string name="qr_code_login_new_device_instruction_2">Go to Settings -> Security &amp; Privacy</string>
+    <string name="qr_code_login_new_device_instruction_3">Select \'Show QR code\'</string>
     <string name="qr_code_login_link_a_device_scan_qr_code_instruction_1">Start at the sign in screen</string>
     <string name="qr_code_login_link_a_device_scan_qr_code_instruction_2">Select \'Sign in with QR code\'</string>
     <string name="qr_code_login_link_a_device_show_qr_code_instruction_1">Start at the sign in screen</string>

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/logger/LoggerTag.kt

@@ -27,6 +27,7 @@ open class LoggerTag(name: String, parentTag: LoggerTag? = null) {
     object SYNC : LoggerTag("SYNC")
     object VOIP : LoggerTag("VOIP")
     object CRYPTO : LoggerTag("CRYPTO")
+    object RENDEZVOUS : LoggerTag("RZ")
 
     val value: String = if (parentTag == null) {
         name

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/rendezvous/Rendezvous.kt

@@ -0,0 +1,229 @@
+/*
+ * Copyright 2022 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.
+ */
+
+package org.matrix.android.sdk.api.rendezvous
+
+import android.net.Uri
+import org.matrix.android.sdk.api.auth.AuthenticationService
+import org.matrix.android.sdk.api.auth.data.HomeServerConnectionConfig
+import org.matrix.android.sdk.api.logger.LoggerTag
+import org.matrix.android.sdk.api.rendezvous.channels.ECDHRendezvousChannel
+import org.matrix.android.sdk.api.rendezvous.model.ECDHRendezvousCode
+import org.matrix.android.sdk.api.rendezvous.model.Outcome
+import org.matrix.android.sdk.api.rendezvous.model.Payload
+import org.matrix.android.sdk.api.rendezvous.model.PayloadType
+import org.matrix.android.sdk.api.rendezvous.model.Protocol
+import org.matrix.android.sdk.api.rendezvous.model.RendezvousError
+import org.matrix.android.sdk.api.rendezvous.model.RendezvousIntent
+import org.matrix.android.sdk.api.rendezvous.transports.SimpleHttpRendezvousTransport
+import org.matrix.android.sdk.api.session.Session
+import org.matrix.android.sdk.api.session.crypto.crosssigning.DeviceTrustLevel
+import org.matrix.android.sdk.api.session.crypto.crosssigning.KEYBACKUP_SECRET_SSSS_NAME
+import org.matrix.android.sdk.api.session.crypto.crosssigning.MASTER_KEY_SSSS_NAME
+import org.matrix.android.sdk.api.session.crypto.crosssigning.SELF_SIGNING_KEY_SSSS_NAME
+import org.matrix.android.sdk.api.session.crypto.crosssigning.USER_SIGNING_KEY_SSSS_NAME
+import org.matrix.android.sdk.api.util.MatrixJsonParser
+import timber.log.Timber
+
+/**
+ * Implementation of MSC3906 to sign in + E2EE set up using a QR code.
+ */
+class Rendezvous(
+        val channel: RendezvousChannel,
+        val theirIntent: RendezvousIntent,
+) {
+    companion object {
+        private val TAG = LoggerTag(Rendezvous::class.java.simpleName, LoggerTag.RENDEZVOUS).value
+
+        @Throws(RendezvousError::class)
+        fun buildChannelFromCode(code: String): Rendezvous {
+            val parsed = try {
+                // we rely on moshi validating the code and throwing exception if invalid JSON or doesn't
+                MatrixJsonParser.getMoshi().adapter(ECDHRendezvousCode::class.java).fromJson(code)
+            } catch (a: Throwable) {
+                throw RendezvousError("Invalid code", RendezvousFailureReason.InvalidCode)
+            } ?: throw RendezvousError("Invalid code", RendezvousFailureReason.InvalidCode)
+
+            val transport = SimpleHttpRendezvousTransport(parsed.rendezvous.transport.uri)
+
+            return Rendezvous(
+                    ECDHRendezvousChannel(transport, parsed.rendezvous.key),
+                    parsed.intent
+            )
+        }
+    }
+
+    private val adapter = MatrixJsonParser.getMoshi().adapter(Payload::class.java)
+
+    // not yet implemented: RendezvousIntent.RECIPROCATE_LOGIN_ON_EXISTING_DEVICE
+    val ourIntent: RendezvousIntent = RendezvousIntent.LOGIN_ON_NEW_DEVICE
+
+    @Throws(RendezvousError::class)
+    private suspend fun checkCompatibility() {
+        val incompatible = theirIntent == ourIntent
+
+        Timber.tag(TAG).d("ourIntent: $ourIntent, theirIntent: $theirIntent, incompatible: $incompatible")
+
+        if (incompatible) {
+            // inform the other side
+            send(Payload(PayloadType.FINISH, intent = ourIntent))
+            if (ourIntent == RendezvousIntent.LOGIN_ON_NEW_DEVICE) {
+                throw RendezvousError("The other device isn't signed in", RendezvousFailureReason.OtherDeviceNotSignedIn)
+            } else {
+                throw RendezvousError("The other device is already signed in", RendezvousFailureReason.OtherDeviceAlreadySignedIn)
+            }
+        }
+    }
+
+    @Throws(RendezvousError::class)
+    suspend fun startAfterScanningCode(): String {
+        val checksum = channel.connect()
+
+        Timber.tag(TAG).i("Connected to secure channel with checksum: $checksum")
+
+        checkCompatibility()
+
+        // get protocols
+        Timber.tag(TAG).i("Waiting for protocols")
+        val protocolsResponse = receive()
+
+        if (protocolsResponse?.protocols == null || !protocolsResponse.protocols.contains(Protocol.LOGIN_TOKEN)) {
+            send(Payload(PayloadType.FINISH, outcome = Outcome.UNSUPPORTED))
+            throw RendezvousError("Unsupported protocols", RendezvousFailureReason.UnsupportedHomeserver)
+        }
+
+        send(Payload(PayloadType.PROGRESS, protocol = Protocol.LOGIN_TOKEN))
+
+        return checksum
+    }
+
+    @Throws(RendezvousError::class)
+    suspend fun waitForLoginOnNewDevice(authenticationService: AuthenticationService): Session {
+        Timber.tag(TAG).i("Waiting for login_token")
+
+        val loginToken = receive()
+
+        if (loginToken?.type == PayloadType.FINISH) {
+            when (loginToken.outcome) {
+                Outcome.DECLINED -> {
+                    throw RendezvousError("Login declined by other device", RendezvousFailureReason.UserDeclined)
+                }
+                Outcome.UNSUPPORTED -> {
+                    throw RendezvousError("Homeserver lacks support", RendezvousFailureReason.UnsupportedHomeserver)
+                }
+                else -> {
+                    throw RendezvousError("Unknown error", RendezvousFailureReason.Unknown)
+                }
+            }
+        }
+
+        val homeserver = loginToken?.homeserver ?: throw RendezvousError("No homeserver returned", RendezvousFailureReason.ProtocolError)
+        val token = loginToken.loginToken ?: throw RendezvousError("No login token returned", RendezvousFailureReason.ProtocolError)
+
+        Timber.tag(TAG).i("Got login_token now attempting to sign in with $homeserver")
+
+        val hsConfig = HomeServerConnectionConfig(homeServerUri = Uri.parse(homeserver))
+        return authenticationService.loginUsingQrLoginToken(hsConfig, token)
+    }
+
+    @Throws(RendezvousError::class)
+    suspend fun completeVerificationOnNewDevice(session: Session) {
+        val userId = session.myUserId
+        val crypto = session.cryptoService()
+        val deviceId = crypto.getMyDevice().deviceId
+        val deviceKey = crypto.getMyDevice().fingerprint()
+        send(Payload(PayloadType.PROGRESS, outcome = Outcome.SUCCESS, deviceId = deviceId, deviceKey = deviceKey))
+
+        // await confirmation of verification
+        val verificationResponse = receive()
+        if (verificationResponse?.outcome == Outcome.VERIFIED) {
+            val verifyingDeviceId = verificationResponse.verifyingDeviceId
+                    ?: throw RendezvousError("No verifying device id returned", RendezvousFailureReason.ProtocolError)
+            val verifyingDeviceFromServer = crypto.getCryptoDeviceInfo(userId, verifyingDeviceId)
+            if (verifyingDeviceFromServer?.fingerprint() != verificationResponse.verifyingDeviceKey) {
+                Timber.tag(TAG).w(
+                        "Verifying device $verifyingDeviceId key doesn't match: ${
+                            verifyingDeviceFromServer?.fingerprint()
+                        } vs ${verificationResponse.verifyingDeviceKey})"
+                )
+                // inform the other side
+                send(Payload(PayloadType.FINISH, outcome = Outcome.E2EE_SECURITY_ERROR))
+                throw RendezvousError("Key from verifying device doesn't match", RendezvousFailureReason.E2EESecurityIssue)
+            }
+
+            verificationResponse.masterKey?.let { masterKeyFromVerifyingDevice ->
+                // verifying device provided us with a master key, so use it to check integrity
+
+                // see what the homeserver told us
+                val localMasterKey = crypto.crossSigningService().getMyCrossSigningKeys()?.masterKey()
+
+                // n.b. if no local master key this is a problem, as well as it not matching
+                if (localMasterKey?.unpaddedBase64PublicKey != masterKeyFromVerifyingDevice) {
+                    Timber.tag(TAG).w("Master key from verifying device doesn't match: $masterKeyFromVerifyingDevice vs $localMasterKey")
+                    // inform the other side
+                    send(Payload(PayloadType.FINISH, outcome = Outcome.E2EE_SECURITY_ERROR))
+                    throw RendezvousError("Master key from verifying device doesn't match", RendezvousFailureReason.E2EESecurityIssue)
+                }
+
+                // set other device as verified
+                Timber.tag(TAG).i("Setting device $verifyingDeviceId as verified")
+                crypto.setDeviceVerification(DeviceTrustLevel(locallyVerified = true, crossSigningVerified = false), userId, verifyingDeviceId)
+
+                Timber.tag(TAG).i("Setting master key as trusted")
+                crypto.crossSigningService().markMyMasterKeyAsTrusted()
+            } ?: run {
+                // set other device as verified anyway
+                Timber.tag(TAG).i("Setting device $verifyingDeviceId as verified")
+                crypto.setDeviceVerification(DeviceTrustLevel(locallyVerified = true, crossSigningVerified = false), userId, verifyingDeviceId)
+
+                Timber.tag(TAG).i("No master key given by verifying device")
+            }
+
+            // request secrets from the verifying device
+            Timber.tag(TAG).i("Requesting secrets from $verifyingDeviceId")
+
+            session.sharedSecretStorageService().let {
+                it.requestSecret(MASTER_KEY_SSSS_NAME, verifyingDeviceId)
+                it.requestSecret(SELF_SIGNING_KEY_SSSS_NAME, verifyingDeviceId)
+                it.requestSecret(USER_SIGNING_KEY_SSSS_NAME, verifyingDeviceId)
+                it.requestSecret(KEYBACKUP_SECRET_SSSS_NAME, verifyingDeviceId)
+            }
+        } else {
+            Timber.tag(TAG).i("Not doing verification")
+        }
+    }
+
+    @Throws(RendezvousError::class)
+    private suspend fun receive(): Payload? {
+        val data = channel.receive() ?: return null
+        val payload = try {
+            adapter.fromJson(data.toString(Charsets.UTF_8))
+        } catch (e: Exception) {
+            Timber.tag(TAG).w(e, "Failed to parse payload")
+            throw RendezvousError("Invalid payload received", RendezvousFailureReason.Unknown)
+        }
+
+        return payload
+    }
+
+    private suspend fun send(payload: Payload) {
+        channel.send(adapter.toJson(payload).toByteArray(Charsets.UTF_8))
+    }
+
+    suspend fun close() {
+        channel.close()
+    }
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/rendezvous/RendezvousChannel.kt

@@ -0,0 +1,51 @@
+/*
+ * Copyright 2022 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.
+ */
+
+package org.matrix.android.sdk.api.rendezvous
+
+import org.matrix.android.sdk.api.rendezvous.model.RendezvousError
+
+/**
+ * Representation of a rendezvous channel such as that described by MSC3903.
+ */
+interface RendezvousChannel {
+    var transport: RendezvousTransport
+
+    /**
+     * @returns the checksum/confirmation digits to be shown to the user
+     */
+    @Throws(RendezvousError::class)
+    suspend fun connect(): String
+
+    /**
+     * Send a payload via the channel.
+     * @param data payload to send
+     */
+    @Throws(RendezvousError::class)
+    suspend fun send(data: ByteArray)
+
+    /**
+     * Receive a payload from the channel.
+     * @returns the received payload
+     */
+    @Throws(RendezvousError::class)
+    suspend fun receive(): ByteArray?
+
+    /**
+     * @returns closes the channel and cleans up
+     */
+    suspend fun close()
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/rendezvous/RendezvousFailureReason.kt

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2022 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.
+ */
+
+package org.matrix.android.sdk.api.rendezvous
+
+enum class RendezvousFailureReason(val canRetry: Boolean = true) {
+    UserDeclined,
+    OtherDeviceNotSignedIn,
+    OtherDeviceAlreadySignedIn,
+    Unknown,
+    Expired,
+    UserCancelled,
+    InvalidCode,
+    UnsupportedAlgorithm(false),
+    UnsupportedTransport(false),
+    UnsupportedHomeserver(false),
+    ProtocolError,
+    E2EESecurityIssue(false)
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/api/rendezvous/RendezvousTransport.kt

@@ -0,0 +1,36 @@
+/*
+ * Copyright 2022 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.
+ */
+
+package org.matrix.android.sdk.api.rendezvous
+
+import okhttp3.MediaType
+import org.matrix.android.sdk.api.rendezvous.model.RendezvousError
+import org.matrix.android.sdk.api.rendezvous.model.RendezvousTransportDetails
+
+interface RendezvousTransport {
+    var ready: Boolean
+
+    @Throws(RendezvousError::class)
+    suspend fun details(): RendezvousTransportDetails
+
+    @Throws(RendezvousError::class)
+    suspend fun send(contentType: MediaType, data: ByteArray)
+
+    @Throws(RendezvousError::class)
+    suspend fun receive(): ByteArray?
+
+    suspend fun close()
+}