Complete Android adaptive and accessibility hardening (#105)

android/platform/src/androidTest/kotlin/de/rfc1437/ironstorage/platform/AndroidKeystoreTest.kt

@@ -1,5 +1,6 @@
 package de.rfc1437.ironstorage.platform
 
+import android.os.Build
 import android.security.keystore.KeyInfo
 import androidx.test.core.app.ActivityScenario
 import androidx.test.filters.SdkSuppress
@@ -35,7 +36,7 @@ class AndroidKeystoreTest {
     ) = KeystoreKeySpecification(
         alias,
         auth,
-        true,
+        Build.VERSION.SDK_INT >= 28,
         auth == KeystoreAuthorization.StrongBiometric,
         false
     )
@@ -51,6 +52,23 @@ class AndroidKeystoreTest {
         }
     }
 
+    @Test
+    @SdkSuppress(maxSdkVersion = 27)
+    fun unsupportedUnlockedDeviceFlagDoesNotCreateAKey() {
+        val os = AndroidKeystoreAdapter(context)
+        val alias = alias()
+        try {
+            failure(KeystoreFailure.UnsupportedProtection) {
+                os.createKey(
+                    KeystoreKeySpecification(alias, KeystoreAuthorization.None, true, false, false)
+                )
+            }
+            assertFalse(os.aliases().contains(alias))
+        } finally {
+            os.deleteKey(alias)
+        }
+    }
+
     @Test fun deviceUnlockedRoundtripReplaceDeleteAndTamper() {
         val os = AndroidKeystoreAdapter(context)
         assertFalse(os.deviceState().locked)

android/platform/src/androidTest/kotlin/de/rfc1437/ironstorage/platform/AndroidQrCameraTest.kt

@@ -2,16 +2,51 @@ package de.rfc1437.ironstorage.platform
 
 import android.Manifest
 import android.content.pm.PackageManager
+import androidx.lifecycle.Lifecycle
 import androidx.test.core.app.ActivityScenario
 import androidx.test.platform.app.InstrumentationRegistry
 import java.util.concurrent.CountDownLatch
 import java.util.concurrent.TimeUnit
+import java.util.concurrent.atomic.AtomicInteger
+import java.util.concurrent.atomic.AtomicReference
 import org.junit.Assert.assertEquals
 import org.junit.Assert.assertFalse
 import org.junit.Assert.assertTrue
 import org.junit.Test
 
 class AndroidQrCameraTest {
+    @Test fun backgroundStopsAnalysisAndResumeRestartsPreview() {
+        val frames = AtomicInteger()
+        val received = AtomicReference(CountDownLatch(1))
+        ActivityScenario.launch(KeystoreTestActivity::class.java).use { activity ->
+            var camera: AndroidQrCamera? = null
+            activity.onActivity { host ->
+                camera = AndroidQrCamera(host, { frame ->
+                    try {
+                        frames.incrementAndGet()
+                        received.get().countDown()
+                    } finally {
+                        frame.pixels.fill(0)
+                    }
+                }, { throw AssertionError("CameraX failed to bind") })
+                host.setContentView(requireNotNull(camera).view)
+            }
+            try {
+                assertTrue(received.get().await(15, TimeUnit.SECONDS))
+                activity.moveToState(Lifecycle.State.CREATED)
+                Thread.sleep(500)
+                val stopped = frames.get()
+                Thread.sleep(500)
+                assertEquals("Background camera analysis must stop", stopped, frames.get())
+                received.set(CountDownLatch(1))
+                activity.moveToState(Lifecycle.State.RESUMED)
+                assertTrue("Camera preview must resume", received.get().await(15, TimeUnit.SECONDS))
+            } finally {
+                activity.onActivity { camera?.close() }
+            }
+        }
+    }
+
     @Test fun livePreviewDeliversBoundedPlanesAndCanBeClosedAndReopened() {
         val context = InstrumentationRegistry.getInstrumentation().targetContext
         assertEquals(