Add multiplatform BLE stack for ISO/IEC 18013-5:2021 proximity.

This adds new multiplatform API to the identity-mdoc library for
ISO/IEC 18013-5:2021 proximity presentations. It works on both Android
and iOS and both operating systems share a lot of common code.

Also add support two new pages - "ISO mdoc Proximity Sharing" and "ISO
mdoc Proximity Reading" - to the multi-platform test app. This only
includes QR engagement, NFC engagement will be added in a future
change. These two pages represent feature complete mDL and mDL reader
functionality and are designed to work with other implementations as
well as with itself.

Also introduce `rememberBluetoothPermissionState` composable function
and `BluetoothPermissionState` object which can be used to obtain the
required permissions on BLE on both Android and iOS.

Also devise a new multi-testing framework for automatically testing a
number of mDL presentations between two devices. This is available in
a new "ISO mdc Multi-Device Testing" page in the test app and the way
it works is that the 1st device offers a QR code that the 2nd device
scans. This sets up a TCP/IP control plane used for initiating tests,
including sharing `DeviceEngagement`. This helps ensure the code is
robust and well-tested both for happy paths and with all the various
termination options available in the standard.

Also modify existing L2CAP support so it follows the latest draft of
the upcoming second edition of ISO 18013-5:2021. In particular, this
means framing the `SessionData` / `SessionEstablishment` packets sent
over the L2CAP socket.

Modify `ScanQrCodeDialog` and `ShowQrCodeDialog` so they are easy to
extend.

Include portrait ans signature images in sample data in
identity-doctypes.

Test: Manually tested against wallet app and well-known readers.

Signed-off-by: David Zeuthen <[email protected]>

gradle/libs.versions.toml

@@ -55,7 +55,8 @@ navigation-plugin = "2.7.7"
 androidx-preference = "1.2.1"
 exif = "1.3.7"
 ausweis-sdk = "2.1.1"
-jetbrains-navigation = "2.7.0-alpha07"
+jetbrains-navigation = "2.8.0-alpha10"
+jetbrains-lifecycle = "2.8.2"
 cameraLifecycle = "1.3.4"
 buildconfig = "5.3.5"
 qrose = "1.0.1"
@@ -99,12 +100,14 @@ androidx-navigation-runtime = { group = "androidx.navigation", name = "navigatio
 androidx-navigation-compose = { group = "androidx.navigation", name = "navigation-compose", version.ref = "androidx-navigation" }
 code-scanner = { module = "com.github.yuriy-budiyev:code-scanner", version.ref = "code-scanner" }
 ktor-client-android = { module = "io.ktor:ktor-client-android", version.ref = "ktor" }
+ktor-client-darwin = { module = "io.ktor:ktor-client-darwin", version.ref = "ktor" }
 ktor-client-core = { module = "io.ktor:ktor-client-core", version.ref = "ktor" }
 ktor-client-java = { module = "io.ktor:ktor-client-java", version.ref = "ktor" }
 ktor-client-content-negotiation = { module = "io.ktor:ktor-client-content-negotiation", version.ref = "ktor" }
 ktor-serialization-kotlinx-json = { module = "io.ktor:ktor-serialization-kotlinx-json", version.ref = "ktor" }
 ktor-client-mock = { module = "io.ktor:ktor-client-mock", version.ref = "ktor" }
 javax-servlet-api = { module = "javax.servlet:javax.servlet-api", version.ref = "javax-servlet-api" }
+ktor-network = { module = "io.ktor:ktor-network", version.ref = "ktor" }
 androidx-lifecycle-extensions = { module = "androidx.lifecycle:lifecycle-extensions", version.ref = "androidx-lifecycle" }
 androidx-lifecycle-livedata = { module = "androidx.lifecycle:lifecycle-livedata-ktx", version.ref = "androidx-lifecycle-ktx" }
 androidx-lifecycle-viewmodel = { module = "androidx.lifecycle:lifecycle-viewmodel-ktx", version.ref = "androidx-lifecycle-ktx" }
@@ -127,6 +130,7 @@ exifinterface = { module = "androidx.exifinterface:exifinterface", version.ref =
 ausweis-sdk = { module = "com.governikus:ausweisapp", version.ref = "ausweis-sdk"}
 jetbrains-navigation-compose = { module = "org.jetbrains.androidx.navigation:navigation-compose", version.ref="jetbrains-navigation" }
 jetbrains-navigation-runtime = { module = "org.jetbrains.androidx.navigation:navigation-runtime", version.ref="jetbrains-navigation" }
+jetbrains-lifecycle-viewmodel-compose = { module = "org.jetbrains.androidx.lifecycle:lifecycle-viewmodel-compose", version.ref="jetbrains-lifecycle" }
 camera-lifecycle = { group = "androidx.camera", name = "camera-lifecycle", version.ref = "cameraLifecycle" }
 qrose = { group = "io.github.alexzhirkevich", name = "qrose", version.ref="qrose"}
 easyqrscan = { module = "io.github.kalinjul.easyqrscan:scanner", version.ref = "easyqrscan" }

identity-android/src/main/java/com/android/identity/android/mdoc/transport/L2CAPClient.kt

@@ -21,10 +21,10 @@ import android.bluetooth.BluetoothSocket
 import android.content.Context
 import android.os.Build
 import androidx.annotation.RequiresApi
-import com.android.identity.cbor.Cbor
 import com.android.identity.util.Logger
-import java.io.ByteArrayOutputStream
+import kotlinx.io.bytestring.ByteStringBuilder
 import java.io.IOException
+import java.io.InputStream
 import java.util.concurrent.BlockingQueue
 import java.util.concurrent.LinkedTransferQueue
 import java.util.concurrent.TimeUnit
@@ -121,7 +121,6 @@ internal class L2CAPClient(private val context: Context, val listener: Listener)
 
     private fun readFromSocket() {
         Logger.d(TAG, "Start reading socket input")
-        val pendingDataBaos = ByteArrayOutputStream()
 
         // Keep listening to the InputStream until an exception occurs.
         val inputStream = try {
@@ -131,24 +130,19 @@ internal class L2CAPClient(private val context: Context, val listener: Listener)
             return
         }
         while (true) {
-            val buf = ByteArray(DataTransportBle.L2CAP_BUF_SIZE)
             try {
-                val numBytesRead = inputStream.read(buf)
-                if (numBytesRead == -1) {
+                val length = try {
+                    val encodedLength = inputStream.readNOctets(4U)
+                    (encodedLength[0].toUInt().and(0xffU) shl 24) +
+                            (encodedLength[1].toUInt().and(0xffU) shl 16) +
+                            (encodedLength[2].toUInt().and(0xffU) shl 8) +
+                            (encodedLength[3].toUInt().and(0xffU) shl 0)
+                } catch (e: Throwable) {
                     reportPeerDisconnected()
                     break
                 }
-                pendingDataBaos.write(buf, 0, numBytesRead)
-                try {
-                    val pendingData = pendingDataBaos.toByteArray()
-                    val (endOffset, _) = Cbor.decode(pendingData, 0)
-                    val dataItemBytes = pendingData.sliceArray(IntRange(0, endOffset - 1))
-                    pendingDataBaos.reset()
-                    pendingDataBaos.write(pendingData, endOffset, pendingData.size - endOffset)
-                    reportMessageReceived(dataItemBytes)
-                } catch (e: Exception) {
-                    /* not enough data to decode item, do nothing */
-                }
+                val message = inputStream.readNOctets(length)
+                reportMessageReceived(message)
             } catch (e: IOException) {
                 reportError(Error("Error on listening input stream from socket L2CAP", e))
                 break
@@ -157,7 +151,16 @@ internal class L2CAPClient(private val context: Context, val listener: Listener)
     }
 
     fun sendMessage(data: ByteArray) {
-        writerQueue.add(data)
+        val bsb = ByteStringBuilder()
+        val length = data.size.toUInt()
+        bsb.apply {
+            append((length shr 24).and(0xffU).toByte())
+            append((length shr 16).and(0xffU).toByte())
+            append((length shr 8).and(0xffU).toByte())
+            append((length shr 0).and(0xffU).toByte())
+        }
+        bsb.append(data)
+        writerQueue.add(bsb.toByteString().toByteArray())
     }
 
     fun reportPeerConnected() {
@@ -194,4 +197,22 @@ internal class L2CAPClient(private val context: Context, val listener: Listener)
     companion object {
         private const val TAG = "L2CAPClient"
     }
-}
+}
+
+// Cannot call it readNBytes() b/c that's taken on API >= 33
+//
+internal fun InputStream.readNOctets(len: UInt): ByteArray {
+    val bsb = ByteStringBuilder()
+    var remaining = len
+    while (remaining > 0U) {
+        val buf = ByteArray(remaining.toInt())
+        val numBytesRead = this.read(buf, 0, remaining.toInt())
+        if (numBytesRead == -1) {
+            throw IllegalStateException("Failed reading from input stream")
+        }
+        bsb.append(buf)
+        remaining -= buf.size.toUInt()
+    }
+    return bsb.toByteString().toByteArray()
+}
+

identity-android/src/main/java/com/android/identity/android/mdoc/transport/L2CAPServer.kt

@@ -22,6 +22,8 @@ import android.os.Build
 import androidx.annotation.RequiresApi
 import com.android.identity.cbor.Cbor
 import com.android.identity.util.Logger
+import kotlinx.io.bytestring.ByteString
+import kotlinx.io.bytestring.ByteStringBuilder
 import java.io.ByteArrayOutputStream
 import java.io.IOException
 import java.util.concurrent.BlockingQueue
@@ -130,7 +132,6 @@ internal class L2CAPServer(val listener: Listener) {
 
     private fun readFromSocket() {
         Logger.d(TAG, "Start reading socket input")
-        val pendingDataBaos = ByteArrayOutputStream()
 
         // Keep listening to the InputStream until an exception occurs.
         val inputStream = try {
@@ -140,25 +141,19 @@ internal class L2CAPServer(val listener: Listener) {
             return
         }
         while (true) {
-            val buf = ByteArray(DataTransportBle.L2CAP_BUF_SIZE)
             try {
-                val numBytesRead = inputStream.read(buf)
-                if (numBytesRead == -1) {
-                    Logger.d(TAG, "End of stream reading from socket")
+                val length = try {
+                    val encodedLength = inputStream.readNOctets(4U)
+                    (encodedLength[0].toUInt().and(0xffU) shl 24) +
+                            (encodedLength[1].toUInt().and(0xffU) shl 16) +
+                            (encodedLength[2].toUInt().and(0xffU) shl 8) +
+                            (encodedLength[3].toUInt().and(0xffU) shl 0)
+                } catch (e: Throwable) {
                     reportPeerDisconnected()
                     break
                 }
-                pendingDataBaos.write(buf, 0, numBytesRead)
-                try {
-                    val pendingData = pendingDataBaos.toByteArray()
-                    val (endOffset, _) = Cbor.decode(pendingData, 0)
-                    val dataItemBytes = pendingData.sliceArray(IntRange(0, endOffset - 1))
-                    pendingDataBaos.reset()
-                    pendingDataBaos.write(pendingData, endOffset, pendingData.size - endOffset)
-                    reportMessageReceived(dataItemBytes)
-                } catch (e: Exception) {
-                    /* not enough data to decode item, do nothing */
-                }
+                val message = inputStream.readNOctets(length)
+                reportMessageReceived(message)
             } catch (e: IOException) {
                 reportError(Error("Error on listening input stream from socket L2CAP", e))
                 break
@@ -167,7 +162,16 @@ internal class L2CAPServer(val listener: Listener) {
     }
 
     fun sendMessage(data: ByteArray) {
-        writerQueue.add(data)
+        val bsb = ByteStringBuilder()
+        val length = data.size.toUInt()
+        bsb.apply {
+            append((length shr 24).and(0xffU).toByte())
+            append((length shr 16).and(0xffU).toByte())
+            append((length shr 8).and(0xffU).toByte())
+            append((length shr 0).and(0xffU).toByte())
+        }
+        bsb.append(data)
+        writerQueue.add(bsb.toByteString().toByteArray())
     }
 
     fun reportPeerConnected() {

identity-appsupport/build.gradle.kts

@@ -1,3 +1,4 @@
+import org.gradle.kotlin.dsl.implementation
 import org.jetbrains.kotlin.gradle.ExperimentalKotlinGradlePluginApi
 import org.jetbrains.kotlin.gradle.dsl.JvmTarget
 
@@ -11,8 +12,6 @@ plugins {
 kotlin {
     jvmToolchain(17)
 
-    jvm()
-
     androidTarget {
         @OptIn(ExperimentalKotlinGradlePluginApi::class)
         compilerOptions {
@@ -60,19 +59,12 @@ kotlin {
             }
         }
 
-        val jvmMain by getting {
-            dependencies {
-                implementation(libs.bouncy.castle.bcprov)
-                implementation(libs.bouncy.castle.bcpkix)
-                implementation(libs.tink)
-            }
-        }
-
         val androidMain by getting {
             dependencies {
                 implementation(libs.bouncy.castle.bcprov)
                 implementation(libs.bouncy.castle.bcpkix)
                 implementation(libs.tink)
+                implementation(libs.accompanist.permissions)
             }
         }
     }

identity-appsupport/src/androidMain/kotlin/com/android/identity/appsupport/ui/Util.android.kt

@@ -1,5 +1,6 @@
 package com.android.identity.appsupport.ui
 
+import android.graphics.BitmapFactory
 import android.os.Build
 import androidx.compose.foundation.isSystemInDarkTheme
 import androidx.compose.material3.MaterialTheme
@@ -8,6 +9,8 @@ import androidx.compose.material3.dynamicDarkColorScheme
 import androidx.compose.material3.dynamicLightColorScheme
 import androidx.compose.material3.lightColorScheme
 import androidx.compose.runtime.Composable
+import androidx.compose.ui.graphics.ImageBitmap
+import androidx.compose.ui.graphics.asImageBitmap
 import androidx.compose.ui.platform.LocalContext
 
 @Composable
@@ -31,4 +34,8 @@ actual fun AppTheme(content: @Composable () -> Unit) {
         colorScheme = colorScheme,
         content = content
     )
-}
+}
+
+actual fun decodeImage(encodedData: ByteArray): ImageBitmap {
+    return BitmapFactory.decodeByteArray(encodedData, 0, encodedData.size).asImageBitmap()
+}

identity-appsupport/src/androidMain/kotlin/com/android/identity/appsupport/ui/permissions/BluetoothPermissionState.android.kt

@@ -0,0 +1,34 @@
+package com.android.identity.appsupport.ui.permissions
+
+import android.Manifest
+import androidx.compose.runtime.Composable
+import com.google.accompanist.permissions.ExperimentalPermissionsApi
+import com.google.accompanist.permissions.MultiplePermissionsState
+import com.google.accompanist.permissions.rememberMultiplePermissionsState
+
+@OptIn(ExperimentalPermissionsApi::class)
+private class AccompanistBluetoothPermissionState(
+    val multiplePermissionsState: MultiplePermissionsState
+) : BluetoothPermissionState {
+
+    override val isGranted: Boolean
+        get() = multiplePermissionsState.allPermissionsGranted
+
+    override fun launchPermissionRequest() {
+        multiplePermissionsState.launchMultiplePermissionRequest()
+    }
+}
+
+@OptIn(ExperimentalPermissionsApi::class)
+@Composable
+actual fun rememberBluetoothPermissionState(): BluetoothPermissionState {
+    return AccompanistBluetoothPermissionState(
+        rememberMultiplePermissionsState(
+            listOf(
+                Manifest.permission.BLUETOOTH_SCAN,
+                Manifest.permission.BLUETOOTH_CONNECT,
+                Manifest.permission.BLUETOOTH_ADVERTISE,
+            )
+        )
+    )
+}

identity-appsupport/src/commonMain/kotlin/com/android/identity/appsupport/ui/Util.kt

@@ -5,6 +5,7 @@ import androidx.compose.material3.MaterialTheme
 import androidx.compose.material3.darkColorScheme
 import androidx.compose.material3.lightColorScheme
 import androidx.compose.runtime.Composable
+import androidx.compose.ui.graphics.ImageBitmap
 
 @Composable
 expect fun AppTheme(content: @Composable () -> Unit)
@@ -16,3 +17,5 @@ fun AppThemeDefault(content: @Composable () -> Unit) {
         content = content
     )
 }
+
+expect fun decodeImage(encodedData: ByteArray): ImageBitmap

identity-appsupport/src/commonMain/kotlin/com/android/identity/appsupport/ui/permissions/BluetoothPermissionState.kt

@@ -0,0 +1,13 @@
+package com.android.identity.appsupport.ui.permissions
+
+import androidx.compose.runtime.Composable
+
+interface BluetoothPermissionState {
+
+    val isGranted: Boolean
+
+    fun launchPermissionRequest()
+}
+
+@Composable
+expect fun rememberBluetoothPermissionState(): BluetoothPermissionState

identity-appsupport/src/commonMain/kotlin/com/android/identity/appsupport/ui/qrcode/ScanQrCodeDialog.kt

@@ -18,7 +18,8 @@ import org.publicvalue.multiplatform.qrcode.ScannerWithPermissions
  * If the application doesn't have the necessary permission, the user is prompted to grant it.
  *
  * @param title The title of the dialog.
- * @param description The description text to include in the dialog.
+ * @param text The description to include in the dialog, displayed above the QR scanner window.
+ * @param additionalContent Content which is displayed below the QR scanner window.
  * @param dismissButton The text for the dismiss button.
  * @param onCodeScanned called when a QR code is scanned, the parameter is the parsed data. Should
  *   return `true` to stop scanning, `false` to continue scanning.
@@ -27,21 +28,22 @@ import org.publicvalue.multiplatform.qrcode.ScannerWithPermissions
  */
 @Composable
 fun ScanQrCodeDialog(
-    title: String,
-    description: String,
+    title: (@Composable () -> Unit)? = null,
+    text: (@Composable () -> Unit)? = null,
+    additionalContent: (@Composable () -> Unit)? = null,
     dismissButton: String,
     onCodeScanned: (data: String) -> Boolean,
     onDismiss: () -> Unit,
     modifier: Modifier? = null
 ) {
     AlertDialog(
         modifier = modifier ?: Modifier,
-        title = { Text(text = title) },
+        title = title,
         text = {
             Column(
                 verticalArrangement = Arrangement.spacedBy(16.dp),
             ) {
-                Text(text = description)
+                text?.invoke()
 
                 ScannerWithPermissions(
                     modifier = Modifier.height(300.dp),
@@ -50,6 +52,8 @@ fun ScanQrCodeDialog(
                     },
                     types = listOf(CodeType.QR)
                 )
+
+                additionalContent?.invoke()
             }
         },
         onDismissRequest = onDismiss,