Feature/aris/issue 465 scrub exif data (#4248)

Implement ImageExifTagRemover to scrub user sensitive data while sending original size photos
- Return a not scrubbed file when there is an exception while scrubbing the jpeg file
- Improve error handling on image compression

changelog.d/4264.misc

@@ -0,0 +1 @@
+Uppon sharing image compression fails, return the original image

changelog.d/465.misc

@@ -0,0 +1 @@
+Scrub user sensitive data like gps location from images when sending on original quality

dependencies.gradle

@@ -130,6 +130,9 @@ ext.libs = [
                 'emojiMaterial'          : "com.vanniktech:emoji-material:$vanniktechEmoji",
                 'emojiGoogle'            : "com.vanniktech:emoji-google:$vanniktechEmoji"
         ],
+        apache:[
+                'commonsImaging'         : "org.apache.sanselan:sanselan:0.97-incubator"
+        ],
         tests       : [
                 'kluent'                 : "org.amshove.kluent:kluent-android:1.68",
                 'timberJunitRule'        : "net.lachlanmckee:timber-junit-rule:1.0.1",

matrix-sdk-android/build.gradle

@@ -154,6 +154,9 @@ dependencies {
     // Video compression
     implementation 'com.otaliastudios:transcoder:0.10.4'
 
+    // Exif data handling
+    implementation libs.apache.commonsImaging
+
     // Phone number https://github.com/google/libphonenumber
     implementation 'com.googlecode.libphonenumber:libphonenumber:8.12.35'
 

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/content/ImageCompressor.kt

@@ -20,22 +20,23 @@ import android.graphics.Bitmap
 import android.graphics.BitmapFactory
 import android.graphics.Matrix
 import androidx.exifinterface.media.ExifInterface
-import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.withContext
+import org.matrix.android.sdk.api.MatrixCoroutineDispatchers
 import org.matrix.android.sdk.internal.util.TemporaryFileCreator
 import timber.log.Timber
 import java.io.File
 import javax.inject.Inject
 
 internal class ImageCompressor @Inject constructor(
-        private val temporaryFileCreator: TemporaryFileCreator
+        private val temporaryFileCreator: TemporaryFileCreator,
+        private val coroutineDispatchers: MatrixCoroutineDispatchers
 ) {
     suspend fun compress(
             imageFile: File,
             desiredWidth: Int,
             desiredHeight: Int,
             desiredQuality: Int = 80): File {
-        return withContext(Dispatchers.IO) {
+        return withContext(coroutineDispatchers.io) {
             val compressedBitmap = BitmapFactory.Options().run {
                 inJustDecodeBounds = true
                 decodeBitmap(imageFile, this)
@@ -52,6 +53,8 @@ internal class ImageCompressor @Inject constructor(
                 destinationFile.outputStream().use {
                     compressedBitmap.compress(Bitmap.CompressFormat.JPEG, desiredQuality, it)
                 }
+            }.onFailure {
+                return@withContext imageFile
             }
 
             destinationFile

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/content/ImageExifTagRemover.kt

@@ -0,0 +1,86 @@
+/*
+ * Copyright 2021 The Matrix.org Foundation C.I.C.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.matrix.android.sdk.internal.session.content
+
+import kotlinx.coroutines.withContext
+import org.apache.sanselan.Sanselan
+import org.apache.sanselan.formats.jpeg.JpegImageMetadata
+import org.apache.sanselan.formats.jpeg.exifRewrite.ExifRewriter
+import org.apache.sanselan.formats.tiff.constants.ExifTagConstants
+import org.apache.sanselan.formats.tiff.constants.GPSTagConstants
+import org.matrix.android.sdk.api.MatrixCoroutineDispatchers
+import org.matrix.android.sdk.api.extensions.tryOrNull
+import org.matrix.android.sdk.internal.util.TemporaryFileCreator
+import java.io.BufferedOutputStream
+import java.io.File
+import java.io.FileOutputStream
+import javax.inject.Inject
+
+/**
+ * This class is responsible for removing Exif tags from image files
+ */
+
+internal class ImageExifTagRemover @Inject constructor(
+        private val temporaryFileCreator: TemporaryFileCreator,
+        private val coroutineDispatchers: MatrixCoroutineDispatchers
+) {
+
+    /**
+     * Remove sensitive exif tags from a jpeg image file.
+     * Scrubbing exif tags like GPS location and user comments
+     * @param jpegImageFile The image file to be scrubbed
+     * @return the new scrubbed image file, or the original file if the operation failed
+     */
+    suspend fun removeSensitiveJpegExifTags(jpegImageFile: File): File = withContext(coroutineDispatchers.io) {
+        val outputSet = tryOrNull("Unable to read JpegImageMetadata") {
+            (Sanselan.getMetadata(jpegImageFile) as? JpegImageMetadata)?.exif?.outputSet
+        } ?: return@withContext jpegImageFile
+
+        tryOrNull("Unable to remove ExifData") {
+            outputSet.removeField(ExifTagConstants.EXIF_TAG_GPSINFO)
+            outputSet.removeField(ExifTagConstants.EXIF_TAG_SUBJECT_LOCATION_1)
+            outputSet.removeField(ExifTagConstants.EXIF_TAG_SUBJECT_LOCATION_2)
+            outputSet.removeField(ExifTagConstants.EXIF_TAG_USER_COMMENT)
+            outputSet.removeField(GPSTagConstants.GPS_TAG_GPS_ALTITUDE)
+            outputSet.removeField(GPSTagConstants.GPS_TAG_GPS_ALTITUDE_REF)
+            outputSet.removeField(GPSTagConstants.GPS_TAG_GPS_LONGITUDE)
+            outputSet.removeField(GPSTagConstants.GPS_TAG_GPS_LONGITUDE_REF)
+            outputSet.removeField(GPSTagConstants.GPS_TAG_GPS_DEST_LONGITUDE)
+            outputSet.removeField(GPSTagConstants.GPS_TAG_GPS_DEST_LONGITUDE_REF)
+            outputSet.removeField(GPSTagConstants.GPS_TAG_GPS_LATITUDE)
+            outputSet.removeField(GPSTagConstants.GPS_TAG_GPS_LATITUDE_REF)
+            outputSet.removeField(GPSTagConstants.GPS_TAG_GPS_DEST_LATITUDE)
+            outputSet.removeField(GPSTagConstants.GPS_TAG_GPS_DEST_LATITUDE_REF)
+        } ?: return@withContext jpegImageFile
+
+        val scrubbedFile = temporaryFileCreator.create()
+        return@withContext runCatching {
+            FileOutputStream(scrubbedFile).use { fos ->
+                val outputStream = BufferedOutputStream(fos)
+                ExifRewriter().updateExifMetadataLossless(jpegImageFile, outputStream, outputSet)
+            }
+        }.fold(
+                onSuccess = {
+                    scrubbedFile
+                },
+                onFailure = {
+                    scrubbedFile.delete()
+                    jpegImageFile
+                }
+        )
+    }
+}

matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/content/UploadContentWorker.kt

@@ -64,7 +64,7 @@ private data class NewAttachmentAttributes(
  * Possible next worker    : Always [MultipleEventSendingDispatcherWorker]
  */
 internal class UploadContentWorker(val context: Context, params: WorkerParameters) :
-    SessionSafeCoroutineWorker<UploadContentWorker.Params>(context, params, Params::class.java) {
+        SessionSafeCoroutineWorker<UploadContentWorker.Params>(context, params, Params::class.java) {
 
     @JsonClass(generateAdapter = true)
     internal data class Params(
@@ -81,6 +81,7 @@ internal class UploadContentWorker(val context: Context, params: WorkerParameter
     @Inject lateinit var fileService: DefaultFileService
     @Inject lateinit var cancelSendTracker: CancelSendTracker
     @Inject lateinit var imageCompressor: ImageCompressor
+    @Inject lateinit var imageExitTagRemover: ImageExifTagRemover
     @Inject lateinit var videoCompressor: VideoCompressor
     @Inject lateinit var thumbnailExtractor: ThumbnailExtractor
     @Inject lateinit var localEchoRepository: LocalEchoRepository
@@ -114,7 +115,7 @@ internal class UploadContentWorker(val context: Context, params: WorkerParameter
         }
 
         val attachment = params.attachment
-        val filesToDelete = mutableListOf<File>()
+        val filesToDelete = hashSetOf<File>()
 
         return try {
             val inputStream = context.contentResolver.openInputStream(attachment.queryUri)
@@ -219,6 +220,10 @@ internal class UploadContentWorker(val context: Context, params: WorkerParameter
                                     }
                                 }
                             }
+                } else if (attachment.type == ContentAttachmentData.Type.IMAGE && !params.compressBeforeSending) {
+                    fileToUpload = imageExitTagRemover.removeSensitiveJpegExifTags(workingFile)
+                            .also { filesToDelete.add(it) }
+                    newAttachmentAttributes = newAttachmentAttributes.copy(newFileSize = fileToUpload.length())
                 } else {
                     fileToUpload = workingFile
                     // Fix: OpenableColumns.SIZE may return -1 or 0