Strip EXIF metadata from all JPEG images.

Strip all EXIF metadata from all JPEGs by re-encoding the JPEG. This
will keep all of the necessary visual effects of the tags (by encoding
them directly in the image data) while stripped the EXIF tags
themselves.

src/org/thoughtcrime/securesms/jobs/MmsSendJob.java

@@ -175,7 +175,7 @@ public class MmsSendJob extends SendJob {
     String           lineNumber        = getMyNumber(context);
     Address          destination       = message.getRecipient().getAddress();
     MediaConstraints mediaConstraints  = MediaConstraints.getMmsMediaConstraints(message.getSubscriptionId());
-    List<Attachment> scaledAttachments = scaleAttachments(mediaConstraints, message.getAttachments());
+    List<Attachment> scaledAttachments = scaleAndStripExifFromAttachments(mediaConstraints, message.getAttachments());
 
     if (!TextUtils.isEmpty(lineNumber)) {
       req.setFrom(new EncodedStringValue(lineNumber));

src/org/thoughtcrime/securesms/jobs/PushGroupSendJob.java

@@ -141,7 +141,7 @@ public class PushGroupSendJob extends PushSendJob implements InjectableType {
     Optional<byte[]>              profileKey        = getProfileKey(message.getRecipient());
     List<Address>                 recipients        = getGroupMessageRecipients(groupId, messageId);
     MediaConstraints              mediaConstraints  = MediaConstraints.getPushMediaConstraints();
-    List<Attachment>              scaledAttachments = scaleAttachments(mediaConstraints, message.getAttachments());
+    List<Attachment>              scaledAttachments = scaleAndStripExifFromAttachments(mediaConstraints, message.getAttachments());
     List<SignalServiceAttachment> attachmentStreams = getAttachmentsFor(scaledAttachments);
 
     List<SignalServiceAddress>    addresses;

src/org/thoughtcrime/securesms/jobs/PushMediaSendJob.java

@@ -107,7 +107,7 @@ public class PushMediaSendJob extends PushSendJob implements InjectableType {
     try {
       SignalServiceAddress          address           = getPushAddress(message.getRecipient().getAddress());
       MediaConstraints              mediaConstraints  = MediaConstraints.getPushMediaConstraints();
-      List<Attachment>              scaledAttachments = scaleAttachments(mediaConstraints, message.getAttachments());
+      List<Attachment>              scaledAttachments = scaleAndStripExifFromAttachments(mediaConstraints, message.getAttachments());
       List<SignalServiceAttachment> attachmentStreams = getAttachmentsFor(scaledAttachments);
       Optional<byte[]>              profileKey        = getProfileKey(message.getRecipient());
       SignalServiceDataMessage      mediaMessage      = SignalServiceDataMessage.newBuilder()

src/org/thoughtcrime/securesms/jobs/SendJob.java

@@ -13,6 +13,7 @@ import org.thoughtcrime.securesms.mms.MediaConstraints;
 import org.thoughtcrime.securesms.mms.MediaStream;
 import org.thoughtcrime.securesms.mms.MmsException;
 import org.thoughtcrime.securesms.transport.UndeliverableMessageException;
+import org.thoughtcrime.securesms.util.MediaUtil;
 import org.thoughtcrime.securesms.util.Util;
 import org.whispersystems.jobqueue.JobParameters;
 
@@ -50,8 +51,8 @@ public abstract class SendJob extends MasterSecretJob {
     }
   }
 
-  protected List<Attachment> scaleAttachments(@NonNull MediaConstraints constraints,
-                                              @NonNull List<Attachment> attachments)
+  protected List<Attachment> scaleAndStripExifFromAttachments(@NonNull MediaConstraints constraints,
+                                                              @NonNull List<Attachment> attachments)
       throws UndeliverableMessageException
   {
     AttachmentDatabase attachmentDatabase = DatabaseFactory.getAttachmentDatabase(context);
@@ -60,7 +61,12 @@ public abstract class SendJob extends MasterSecretJob {
     for (Attachment attachment : attachments) {
       try {
         if (constraints.isSatisfied(context, attachment)) {
-          results.add(attachment);
+          if (MediaUtil.isJpeg(attachment)) {
+            MediaStream stripped = constraints.getResizedMedia(context, attachment);
+            results.add(attachmentDatabase.updateAttachmentData(attachment, stripped));
+          } else {
+            results.add(attachment);
+          }
         } else if (constraints.canResize(attachment)) {
           MediaStream resized = constraints.getResizedMedia(context, attachment);
           results.add(attachmentDatabase.updateAttachmentData(attachment, resized));

src/org/thoughtcrime/securesms/util/MediaUtil.java

@@ -149,6 +149,10 @@ public class MediaUtil {
     return isGif(attachment.getContentType());
   }
 
+  public static boolean isJpeg(Attachment attachment) {
+    return isJpegType(attachment.getContentType());
+  }
+
   public static boolean isImage(Attachment attachment) {
     return isImageType(attachment.getContentType());
   }
@@ -169,6 +173,10 @@ public class MediaUtil {
     return !TextUtils.isEmpty(contentType) && contentType.trim().equals("image/gif");
   }
 
+  public static boolean isJpegType(String contentType) {
+    return !TextUtils.isEmpty(contentType) && contentType.trim().equals(IMAGE_JPEG);
+  }
+
   public static boolean isFile(Attachment attachment) {
     return !isGif(attachment) && !isImage(attachment) && !isAudio(attachment) && !isVideo(attachment);
   }