[APT-9577] Add DRM for downloads for offline usage : code improvement…

…s : use injection for SharedPreferences and DrmSessionManagerProvider
scribd · Feb 13, 2024 · 208aa3f · 208aa3f
1 parent 6f182fc
commit 208aa3f
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Showing 5 changed files with 47 additions and 31 deletions.
diff --git a/Armadillo/src/main/java/com/scribd/armadillo/Constants.kt b/Armadillo/src/main/java/com/scribd/armadillo/Constants.kt
@@ -44,6 +44,9 @@ object Constants {
         const val EXOPLAYER_CACHE_DIRECTORY = "exoplayer_cache_directory"
 
         const val GLOBAL_SCOPE = "global_scope"
+
+        const val STANDARD_STORAGE = "standard_storage"
+        const val DRM_DOWNLOAD_STORAGE = "drm_download_storage"
     }
 
     internal object Exoplayer {

diff --git a/Armadillo/src/main/java/com/scribd/armadillo/di/DownloadModule.kt b/Armadillo/src/main/java/com/scribd/armadillo/di/DownloadModule.kt
@@ -1,6 +1,7 @@
 package com.scribd.armadillo.di
 
 import android.content.Context
+import android.content.SharedPreferences
 import com.google.android.exoplayer2.offline.DownloadManager
 import com.google.android.exoplayer2.offline.DownloadService
 import com.google.android.exoplayer2.offline.DownloaderFactory
@@ -98,6 +99,18 @@ internal class DownloadModule {
     @Provides
     fun secureStorage(secureStorage: ArmadilloSecureStorage): SecureStorage = secureStorage
 
+    @Singleton
+    @Provides
+    @Named(Constants.DI.STANDARD_STORAGE)
+    fun standardStorage(context: Context): SharedPreferences =
+        context.getSharedPreferences("armadillo.storage", Context.MODE_PRIVATE)
+
+    @Singleton
+    @Provides
+    @Named(Constants.DI.DRM_DOWNLOAD_STORAGE)
+    fun drmDownloadStorage(context: Context): SharedPreferences =
+        context.getSharedPreferences("armadillo.download.drm", Context.MODE_PRIVATE)
+
     @Singleton
     @Provides
     fun downloadManagerFactory(downloadManagerFactory: ArmadilloDownloadManagerFactory): DownloadManagerFactory = downloadManagerFactory

diff --git a/Armadillo/src/main/java/com/scribd/armadillo/di/PlaybackModule.kt b/Armadillo/src/main/java/com/scribd/armadillo/di/PlaybackModule.kt
@@ -2,6 +2,8 @@ package com.scribd.armadillo.di
 
 import android.app.Application
 import android.content.Context
+import com.google.android.exoplayer2.drm.DefaultDrmSessionManagerProvider
+import com.google.android.exoplayer2.drm.DrmSessionManagerProvider
 import com.scribd.armadillo.broadcast.ArmadilloNoisyReceiver
 import com.scribd.armadillo.broadcast.ArmadilloNoisySpeakerReceiver
 import com.scribd.armadillo.broadcast.ArmadilloNotificationDeleteReceiver
@@ -68,4 +70,8 @@ internal class PlaybackModule {
     @Provides
     @Singleton
     fun drmMediaSourceHelper(drmMediaSourceHelperImpl: DrmMediaSourceHelperImpl): DrmMediaSourceHelper = drmMediaSourceHelperImpl
+
+    @Provides
+    @Singleton
+    fun drmSessionManagerProvider(): DrmSessionManagerProvider = DefaultDrmSessionManagerProvider()
 }
diff --git a/Armadillo/src/main/java/com/scribd/armadillo/encryption/SecureStorage.kt b/Armadillo/src/main/java/com/scribd/armadillo/encryption/SecureStorage.kt
@@ -1,8 +1,10 @@
 package com.scribd.armadillo.encryption
 
 import android.content.Context
+import android.content.SharedPreferences
 import android.util.Base64
 import android.util.Log
+import com.scribd.armadillo.Constants
 import com.scribd.armadillo.models.DrmDownload
 import com.scribd.armadillo.models.DrmType
 import kotlinx.serialization.decodeFromString
@@ -11,6 +13,7 @@ import kotlinx.serialization.json.Json
 import java.nio.charset.StandardCharsets
 import java.security.MessageDigest
 import javax.inject.Inject
+import javax.inject.Named
 import javax.inject.Singleton
 
 internal interface SecureStorage {
@@ -23,28 +26,28 @@ internal interface SecureStorage {
 }
 
 @Singleton
-internal class ArmadilloSecureStorage @Inject constructor() : SecureStorage {
-    private companion object {
+internal class ArmadilloSecureStorage @Inject constructor(
+    @Named(Constants.DI.STANDARD_STORAGE) private val standardStorage: SharedPreferences,
+    @Named(Constants.DI.DRM_DOWNLOAD_STORAGE) private val drmDownloadStorage: SharedPreferences,
+) : SecureStorage {
+    companion object {
         const val DOWNLOAD_KEY = "download_key"
         const val STRING_LENGTH = 20
         const val ALLOWED_CHARS = "ABCDEFGHIJKLMNOPQRSTUVWXTZabcdefghiklmnopqrstuvwxyz0123456789"
         const val DEFAULT = "82YEDKqPBEqA2qAb4bUU"
-        const val STANDARD_STORAGE_FILENAME = "armadillo.storage"
-        const val DOWNLOAD_FILENAME = "armadillo.download"
         const val TAG = "SecureStorage"
     }
 
     override fun downloadSecretKey(context: Context): ByteArray {
-        val sharedPreferences = context.getSharedPreferences(STANDARD_STORAGE_FILENAME, Context.MODE_PRIVATE)
-        return if (sharedPreferences.contains(DOWNLOAD_KEY)) {
-            val storedKey = sharedPreferences.getString(DOWNLOAD_KEY, DEFAULT)!!
+        return if (standardStorage.contains(DOWNLOAD_KEY)) {
+            val storedKey = standardStorage.getString(DOWNLOAD_KEY, DEFAULT)!!
             if (storedKey == DEFAULT) {
                 Log.e(TAG, "Storage Is Out of Alignment")
             }
             storedKey.toSecretByteArray
         } else {
             createRandomString().also {
-                sharedPreferences.edit().putString(DOWNLOAD_KEY, it).apply()
+                standardStorage.edit().putString(DOWNLOAD_KEY, it).apply()
             }.toSecretByteArray
         }
     }
@@ -56,37 +59,27 @@ internal class ArmadilloSecureStorage @Inject constructor() : SecureStorage {
     }
 
     override fun saveDrmDownload(context: Context, audioUrl: String, drmDownload: DrmDownload) {
-        context.getSharedPreferences(DOWNLOAD_FILENAME, Context.MODE_PRIVATE).also { sharedPrefs ->
-            val key = getDrmDownloadKey(audioUrl, drmDownload.drmType)
-            val value = Base64.encodeToString(Json.encodeToString(drmDownload).toByteArray(StandardCharsets.UTF_8), Base64.NO_WRAP)
-            sharedPrefs.edit().putString(key, value).apply()
-        }
+        val key = getDrmDownloadKey(audioUrl, drmDownload.drmType)
+        val value = Base64.encodeToString(Json.encodeToString(drmDownload).toByteArray(StandardCharsets.UTF_8), Base64.NO_WRAP)
+        drmDownloadStorage.edit().putString(key, value).apply()
     }
 
     override fun getDrmDownload(context: Context, audioUrl: String, drmType: DrmType): DrmDownload? =
-        context.getSharedPreferences(DOWNLOAD_FILENAME, Context.MODE_PRIVATE).let { sharedPrefs ->
-            sharedPrefs.getString(getDrmDownloadKey(audioUrl, drmType), null)?.decodeToDrmDownload()
-        }
+        drmDownloadStorage.getString(getDrmDownloadKey(audioUrl, drmType), null)?.decodeToDrmDownload()
 
     override fun getAllDrmDownloads(context: Context): Map<String, DrmDownload> =
-        context.getSharedPreferences(DOWNLOAD_FILENAME, Context.MODE_PRIVATE).let { sharedPrefs ->
-            sharedPrefs.all.keys.mapNotNull { key ->
-                sharedPrefs.getString(key, null)?.let { drmResult ->
-                    key to drmResult.decodeToDrmDownload()
-                }
-            }.toMap()
-        }
+        drmDownloadStorage.all.keys.mapNotNull { key ->
+            drmDownloadStorage.getString(key, null)?.let { drmResult ->
+                key to drmResult.decodeToDrmDownload()
+            }
+        }.toMap()
 
     override fun removeDrmDownload(context: Context, audioUrl: String, drmType: DrmType) {
-        context.getSharedPreferences(DOWNLOAD_FILENAME, Context.MODE_PRIVATE).also { sharedPrefs ->
-            sharedPrefs.edit().remove(getDrmDownloadKey(audioUrl, drmType)).apply()
-        }
+        drmDownloadStorage.edit().remove(getDrmDownloadKey(audioUrl, drmType)).apply()
     }
 
     override fun removeDrmDownload(context: Context, key: String) {
-        context.getSharedPreferences(DOWNLOAD_FILENAME, Context.MODE_PRIVATE).also { sharedPrefs ->
-            sharedPrefs.edit().remove(key).apply()
-        }
+        drmDownloadStorage.edit().remove(key).apply()
     }
 
     private val String.toSecretByteArray: ByteArray

diff --git a/...dillo/src/main/java/com/scribd/armadillo/playback/mediasource/DashMediaSourceGenerator.kt b/...dillo/src/main/java/com/scribd/armadillo/playback/mediasource/DashMediaSourceGenerator.kt
@@ -1,7 +1,7 @@
 package com.scribd.armadillo.playback.mediasource
 
 import android.content.Context
-import com.google.android.exoplayer2.drm.DefaultDrmSessionManagerProvider
+import com.google.android.exoplayer2.drm.DrmSessionManagerProvider
 import com.google.android.exoplayer2.offline.Download
 import com.google.android.exoplayer2.offline.DownloadHelper
 import com.google.android.exoplayer2.source.MediaSource
@@ -15,6 +15,7 @@ internal class DashMediaSourceGenerator @Inject constructor(
     private val mediaSourceHelper: HeadersMediaSourceHelper,
     private val downloadTracker: DownloadTracker,
     private val drmMediaSourceHelper: DrmMediaSourceHelper,
+    private val drmSessionManagerProvider: DrmSessionManagerProvider,
 ) : MediaSourceGenerator {
 
     override fun generateMediaSource(context: Context, request: AudioPlayable.MediaRequest): MediaSource {
@@ -23,7 +24,7 @@ internal class DashMediaSourceGenerator @Inject constructor(
         downloadTracker.getDownload(request.url.toUri())?.let {
             if (it.state != Download.STATE_FAILED) {
                 val mediaItem = drmMediaSourceHelper.createMediaItem(context = context, request = request, isDownload = true)
-                return DownloadHelper.createMediaSource(it.request, dataSourceFactory, DefaultDrmSessionManagerProvider().get(mediaItem))
+                return DownloadHelper.createMediaSource(it.request, dataSourceFactory, drmSessionManagerProvider.get(mediaItem))
             }
         }