fix: switch to stream implementation of base64url encoding

Author: loggerz

app/build.gradle.kts

@@ -199,6 +199,7 @@ dependencies {
     implementation(libs.play.services.location)
     implementation(libs.firebase.messaging.ktx)
     implementation(libs.androidx.datastore.preferences)
+    implementation(libs.firebase.crashlytics.buildtools)
 
     testImplementation(libs.junit)
     globalTestImplementation(libs.androidx.junit)

app/src/main/java/com/github/se/travelpouch/model/documents/DocumentRepository.kt

@@ -4,13 +4,17 @@ package com.github.se.travelpouch.model.documents
 import android.util.Log
 import com.github.se.travelpouch.model.FirebasePaths
 import com.github.se.travelpouch.model.activity.Activity
-import com.google.android.gms.common.util.Base64Utils
 import com.google.firebase.Timestamp
 import com.google.firebase.auth.FirebaseAuth
+import com.google.firebase.crashlytics.buildtools.reloc.org.apache.commons.codec.binary.BaseNCodecOutputStream
 import com.google.firebase.firestore.DocumentSnapshot
 import com.google.firebase.firestore.FirebaseFirestore
 import com.google.firebase.functions.FirebaseFunctions
 import com.google.firebase.storage.FirebaseStorage
+import java.io.ByteArrayOutputStream
+import kotlin.io.encoding.Base64
+import kotlin.io.encoding.ExperimentalEncodingApi
+import kotlin.math.min
 
 /** Interface for the DocumentRepository. */
 interface DocumentRepository {
@@ -30,7 +34,7 @@ interface DocumentRepository {
       bytes: ByteArray,
       format: DocumentFileFormat,
       onSuccess: () -> Unit,
-      onFailure: () -> Int
+      onFailure: (e: Exception) -> Unit
   )
 }
 
@@ -128,20 +132,63 @@ class DocumentRepositoryFirestore(
         }
   }
 
+  /**
+   * Encodes a byte array to a base64URL string using a stream.
+   *
+   * @param bytes The byte array to encode.
+   * @return The base64 encoded string.
+   */
+  @OptIn(ExperimentalEncodingApi::class)
+  private fun base64StreamUploadEncoding(bytes: ByteArray): String? {
+    val byteArrayOutputStream = ByteArrayOutputStream()
+    val base64OutputStream =
+        BaseNCodecOutputStream(
+            byteArrayOutputStream,
+            com.google.firebase.crashlytics.buildtools.reloc.org.apache.commons.codec.binary.Base64(
+                true),
+            true) // urlSafe is a must
+
+    try {
+      val buffer = ByteArray(8192)
+      var offset = 0
+      while (offset < bytes.size) {
+        val chunkSize = min(buffer.size, bytes.size - offset)
+        System.arraycopy(bytes, offset, buffer, 0, chunkSize)
+        base64OutputStream.write(buffer, 0, chunkSize)
+        offset += chunkSize
+      }
+      base64OutputStream.close() // closes but also flushes the stream
+      return byteArrayOutputStream.toString("UTF-8")
+    } catch (e: Exception) {
+      Log.e("DocumentRepositoryFirestore", "Error encoding document", e)
+      return null
+    }
+  }
+
+  /**
+   * Uploads a document to the Firestore database.
+   *
+   * @param travelId The id of the travel the document is linked to.
+   * @param bytes The content of the document.
+   * @param format The format of the document.
+   * @param onSuccess Callback function to be called when the document is uploaded successfully.
+   * @param onFailure Callback function to be called when an error occurs.
+   */
   override fun uploadDocument(
       travelId: String,
       bytes: ByteArray,
       format: DocumentFileFormat,
       onSuccess: () -> Unit,
-      onFailure: () -> Int
+      onFailure: (e: Exception) -> Unit
   ) {
-    val bytes64 = Base64Utils.encodeUrlSafe(bytes)
+    val encodedContent =
+        base64StreamUploadEncoding(bytes) ?: return onFailure(Exception("Error encoding document"))
     val scanTimestamp = Timestamp.now().seconds
     functions
         .getHttpsCallable("storeDocument")
         .call(
             mapOf(
-                "content" to bytes64,
+                "content" to encodedContent,
                 "fileFormat" to format.mimeType,
                 "title" to "Scan $scanTimestamp",
                 "travelId" to travelId,
@@ -152,7 +199,7 @@ class DocumentRepositoryFirestore(
             onSuccess()
           } else {
             Log.e("DocumentRepositoryFirestore", "Error uploading document", task.exception)
-            onFailure()
+            onFailure(task.exception!!)
           }
         }
   }

app/src/main/java/com/github/se/travelpouch/model/documents/DocumentViewModel.kt

@@ -156,7 +156,13 @@ constructor(
     }
   }
 
-  fun uploadDocument(travelId: String, bytes: ByteArray, format: DocumentFileFormat) {
+  fun uploadDocument(
+      travelId: String,
+      bytes: ByteArray,
+      format: DocumentFileFormat,
+      onSuccess: () -> Unit,
+      onFailure: (e: Exception) -> Unit
+  ) {
     _isLoading.value = true // set as loading for spinner
     repository.uploadDocument(
         travelId,
@@ -169,6 +175,7 @@ constructor(
         onFailure = {
           _isLoading.value = false // set as not loading
           Log.e("DocumentsViewModel", "Failed to upload Document")
+          onFailure(it)
         })
   }
 
@@ -179,7 +186,12 @@ constructor(
    * @param selectedTravel The travel to which the file should be uploaded.
    * @param mimeType The mime type of the file.
    */
-  fun uploadFile(inputStream: InputStream?, selectedTravel: TravelContainer?, mimeType: String?) {
+  fun uploadFile(
+      inputStream: InputStream?,
+      selectedTravel: TravelContainer?,
+      mimeType: String?,
+      onFailure: (e: Exception) -> Unit
+  ) {
     if (inputStream == null) {
       Log.e("DocumentViewModel", "No input stream")
       return
@@ -198,7 +210,15 @@ constructor(
     inputStream.copyTo(byteArrayOutputStream)
     val bytes: ByteArray = byteArrayOutputStream.toByteArray()
 
-    uploadDocument(travelId, bytes, format)
+    uploadDocument(
+        travelId,
+        bytes,
+        format,
+        {},
+        {
+          Log.e("DocumentViewModel", "Failed to upload file", it)
+          onFailure(it)
+        })
   }
 
   companion object {

app/src/main/java/com/github/se/travelpouch/ui/documents/DocumentList.kt

@@ -7,6 +7,7 @@ import android.content.ContextWrapper
 import android.net.Uri
 import android.util.Log
 import android.webkit.MimeTypeMap
+import android.widget.Toast
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.rememberLauncherForActivityResult
 import androidx.activity.result.IntentSenderRequest
@@ -103,13 +104,27 @@ fun DocumentListScreen(
                   val bytes = scanningResult.pages?.firstOrNull()?.imageUri?.toFile()?.readBytes()
                   if (bytes != null && selectedTravel.value != null) {
                     documentViewModel.uploadDocument(
-                        selectedTravel.value!!.fsUid, bytes, DocumentFileFormat.JPEG)
+                        selectedTravel.value!!.fsUid,
+                        bytes,
+                        DocumentFileFormat.JPEG,
+                        {},
+                        {
+                          Toast.makeText(context, "Document upload failed", Toast.LENGTH_SHORT)
+                              .show()
+                        })
                   }
                 } else if (size > 1 && selectedTravel.value != null) {
                   scanningResult.pdf?.let { pdf ->
                     val bytes = pdf.uri.toFile().readBytes()
                     documentViewModel.uploadDocument(
-                        selectedTravel.value!!.fsUid, bytes, DocumentFileFormat.PDF)
+                        selectedTravel.value!!.fsUid,
+                        bytes,
+                        DocumentFileFormat.PDF,
+                        {},
+                        {
+                          Toast.makeText(context, "Document upload failed", Toast.LENGTH_SHORT)
+                              .show()
+                        })
                   }
                 }
               }
@@ -125,7 +140,9 @@ fun DocumentListScreen(
                 context.contentResolver.openInputStream(uri),
                 selectedTravel.value,
                 MimeTypeMap.getSingleton()
-                    .getMimeTypeFromExtension(uri.path?.substringAfterLast(".") ?: ""))
+                    .getMimeTypeFromExtension(uri.path?.substringAfterLast(".") ?: "")) {
+                  Toast.makeText(context, "Document upload failed", Toast.LENGTH_SHORT).show()
+                }
         else Log.d("DocumentList", "No file selected")
       }
 

gradle/libs.versions.toml

@@ -78,6 +78,7 @@ playServicesMlkitDocumentScanner = "16.0.0-beta1"
 coil = "2.1.0"
 bouquet = "1.1.2"
 playServicesLocation = "21.3.0"
+firebaseCrashlyticsBuildtools = "3.0.2"
 
 [libraries]
 androidx-concurrent-futures = { module = "androidx.concurrent:concurrent-futures", version.ref = "concurrentFutures" }
@@ -169,6 +170,7 @@ play-services-location = { group = "com.google.android.gms", name = "play-servic
 
 #Permissions
 accompanist-permissions = { group = "com.google.accompanist", name = "accompanist-permissions", version = "0.30.0" }
+firebase-crashlytics-buildtools = { group = "com.google.firebase", name = "firebase-crashlytics-buildtools", version.ref = "firebaseCrashlyticsBuildtools" }
 
 [plugins]
 androidApplication = { id = "com.android.application", version.ref = "agp" }