fix: Drop encryption of non-sensitive data

lib/src/androidTest/java/tech/relaycorp/awaladroid/storage/persistence/EncryptedDiskPersistenceTest.kt → lib/src/androidTest/java/tech/relaycorp/awaladroid/storage/persistence/DiskPersistenceTest.kt

@@ -10,20 +10,19 @@ import kotlinx.coroutines.test.runBlockingTest
 import org.junit.After
 import org.junit.Assert.assertEquals
 import org.junit.Assert.assertFalse
-import org.junit.Assert.assertNotEquals
 import org.junit.Assert.assertNotNull
 import org.junit.Assert.assertNull
 import org.junit.Assert.assertTrue
 import org.junit.Test
 import org.junit.runner.RunWith
 
 @RunWith(AndroidJUnit4::class)
-internal class EncryptedDiskPersistenceTest {
+internal class DiskPersistenceTest {
 
     private val context: Context = ApplicationProvider.getApplicationContext()
     private val coroutineScope = TestCoroutineScope()
     private val rootFolder = "relaydroid_test"
-    private val subject = EncryptedDiskPersistence(
+    private val subject = DiskPersistence(
         context,
         coroutineScope.coroutineContext,
         rootFolder
@@ -58,15 +57,15 @@ internal class EncryptedDiskPersistenceTest {
     }
 
     @Test
-    fun setEncryptsContent() = coroutineScope.runBlockingTest {
+    fun setContent() = coroutineScope.runBlockingTest {
         val location = "file"
         val data = "test"
         subject.set(location, data.toByteArray())
         val fileContent =
             File(context.filesDir, "$rootFolder${File.separator}$location")
                 .readBytes()
                 .toString(Charset.defaultCharset())
-        assertNotEquals(data, fileContent)
+        assertEquals(data, fileContent)
     }
 
     @Test

lib/src/main/java/tech/relaycorp/awaladroid/Awala.kt

@@ -6,7 +6,7 @@ import tech.relaycorp.awala.keystores.file.FileKeystoreRoot
 import tech.relaycorp.awala.keystores.file.FileSessionPublicKeystore
 import tech.relaycorp.awaladroid.background.ServiceInteractor
 import tech.relaycorp.awaladroid.storage.StorageImpl
-import tech.relaycorp.awaladroid.storage.persistence.EncryptedDiskPersistence
+import tech.relaycorp.awaladroid.storage.persistence.DiskPersistence
 import tech.relaycorp.relaynet.nodes.EndpointManager
 
 public object Awala {
@@ -31,7 +31,7 @@ public object Awala {
         val androidPrivateKeyStore = AndroidPrivateKeyStore(keystoreRoot, context)
         val fileSessionPublicKeystore = FileSessionPublicKeystore(keystoreRoot)
         this.context = AwalaContext(
-            StorageImpl(EncryptedDiskPersistence(context)),
+            StorageImpl(DiskPersistence(context)),
             GatewayClientImpl(
                 serviceInteractorBuilder = { ServiceInteractor(context) }
             ),

lib/src/main/java/tech/relaycorp/awaladroid/storage/persistence/EncryptedDiskPersistence.kt → lib/src/main/java/tech/relaycorp/awaladroid/storage/persistence/DiskPersistence.kt

@@ -1,15 +1,13 @@
 package tech.relaycorp.awaladroid.storage.persistence
 
 import android.content.Context
-import androidx.security.crypto.EncryptedFile
-import androidx.security.crypto.MasterKey
 import java.io.File
 import java.io.IOException
 import kotlin.coroutines.CoroutineContext
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
 
-internal class EncryptedDiskPersistence(
+internal class DiskPersistence(
     private val context: Context,
     private val coroutineContext: CoroutineContext = Dispatchers.IO,
     private val rootFolder: String = "awaladroid"
@@ -21,8 +19,8 @@ internal class EncryptedDiskPersistence(
         withContext(coroutineContext) {
             deleteIfExists(location)
             try {
-                buildEncryptedFile(location)
-                    .openFileOutput()
+                buildFile(location)
+                    .outputStream()
                     .use { it.write(data) }
             } catch (exception: IOException) {
                 throw PersistenceException("Failed to write to file at $location", exception)
@@ -34,8 +32,8 @@ internal class EncryptedDiskPersistence(
     @Throws(PersistenceException::class)
     override suspend fun get(location: String): ByteArray? = withContext(coroutineContext) {
         try {
-            buildEncryptedFile(location)
-                .openFileInput()
+            buildFile(location)
+                .inputStream()
                 .use { it.readBytes() }
         } catch (exception: IOException) {
             if (buildFile(location).exists()) {
@@ -82,22 +80,4 @@ internal class EncryptedDiskPersistence(
         File(context.filesDir, "$rootFolder${File.separator}$location").also {
             it.parentFile?.mkdirs()
         }
-
-    private fun buildEncryptedFile(location: String) =
-        EncryptedFile.Builder(
-            context,
-            buildFile(location),
-            masterKey,
-            EncryptedFile.FileEncryptionScheme.AES256_GCM_HKDF_4KB
-        ).build()
-
-    private val masterKey by lazy {
-        MasterKey.Builder(context, MASTER_KEY_ALIAS)
-            .setKeyScheme(MasterKey.KeyScheme.AES256_GCM)
-            .build()
-    }
-
-    companion object {
-        private const val MASTER_KEY_ALIAS = "_relaydroid_master_key_"
-    }
 }