Add initial support for send/receive on CDN2.

app/build.gradle

@@ -115,6 +115,7 @@ android {
         buildConfigField "String", "SIGNAL_URL", "\"https://textsecure-service.whispersystems.org\""
         buildConfigField "String", "STORAGE_URL", "\"https://storage.signal.org\""
         buildConfigField "String", "SIGNAL_CDN_URL", "\"https://cdn.signal.org\""
+        buildConfigField "String", "SIGNAL_CDN2_URL", "\"https://cdn2.signal.org\""
         buildConfigField "String", "SIGNAL_CONTACT_DISCOVERY_URL", "\"https://api.directory.signal.org\""
         buildConfigField "String", "SIGNAL_SERVICE_STATUS_URL", "\"uptime.signal.org\""
         buildConfigField "String", "SIGNAL_KEY_BACKUP_URL", "\"https://api.backup.signal.org\""
@@ -194,6 +195,7 @@ android {
             buildConfigField "String", "SIGNAL_URL", "\"https://textsecure-service-staging.whispersystems.org\""
             buildConfigField "String", "STORAGE_URL", "\"https://storage-staging.signal.org\""
             buildConfigField "String", "SIGNAL_CDN_URL", "\"https://cdn-staging.signal.org\""
+            buildConfigField "String", "SIGNAL_CDN2_URL", "\"https://cdn2-staging.signal.org\""
             buildConfigField "String", "SIGNAL_CONTACT_DISCOVERY_URL", "\"https://api-staging.directory.signal.org\""
             buildConfigField "String", "SIGNAL_KEY_BACKUP_URL", "\"https://api-staging.backup.signal.org\""
             buildConfigField "String", "MRENCLAVE", "\"ba4ebb438bc07713819ee6c98d94037747006d7df63fc9e44d2d6f1fec962a79\""

app/src/main/java/org/thoughtcrime/securesms/attachments/Attachment.java

@@ -19,6 +19,8 @@ public abstract class Attachment {
   @Nullable
   private final String fileName;
 
+  private final int    cdnNumber;
+
   @Nullable
   private final String  location;
 
@@ -53,7 +55,7 @@ public abstract class Attachment {
   private final TransformProperties transformProperties;
 
   public Attachment(@NonNull String contentType, int transferState, long size, @Nullable String fileName,
-                    @Nullable String location, @Nullable String key, @Nullable String relay,
+                    int cdnNumber, @Nullable String location, @Nullable String key, @Nullable String relay,
                     @Nullable byte[] digest, @Nullable String fastPreflightId, boolean voiceNote,
                     int width, int height, boolean quote, long uploadTimestamp, @Nullable String caption,
                     @Nullable StickerLocator stickerLocator, @Nullable BlurHash blurHash,
@@ -63,6 +65,7 @@ public abstract class Attachment {
     this.transferState       = transferState;
     this.size                = size;
     this.fileName            = fileName;
+    this.cdnNumber           = cdnNumber;
     this.location            = location;
     this.key                 = key;
     this.relay               = relay;
@@ -108,6 +111,10 @@ public abstract class Attachment {
     return contentType;
   }
 
+  public int getCdnNumber() {
+    return cdnNumber;
+  }
+
   @Nullable
   public String getLocation() {
     return location;

app/src/main/java/org/thoughtcrime/securesms/attachments/DatabaseAttachment.java

@@ -2,11 +2,9 @@ package org.thoughtcrime.securesms.attachments;
 
 import android.net.Uri;
 
-import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
 import org.thoughtcrime.securesms.blurhash.BlurHash;
-import org.thoughtcrime.securesms.database.AttachmentDatabase;
 import org.thoughtcrime.securesms.database.AttachmentDatabase.TransformProperties;
 import org.thoughtcrime.securesms.mms.PartAuthority;
 import org.thoughtcrime.securesms.stickers.StickerLocator;
@@ -24,14 +22,14 @@ public class DatabaseAttachment extends Attachment {
   public DatabaseAttachment(AttachmentId attachmentId, long mmsId,
                             boolean hasData, boolean hasThumbnail,
                             String contentType, int transferProgress, long size,
-                            String fileName, String location, String key, String relay,
+                            String fileName, int cdnNumber, String location, String key, String relay,
                             byte[] digest, String fastPreflightId, boolean voiceNote,
                             int width, int height, boolean quote, @Nullable String caption,
                             @Nullable StickerLocator stickerLocator, @Nullable BlurHash blurHash,
                             @Nullable TransformProperties transformProperties, int displayOrder,
                             long uploadTimestamp)
   {
-    super(contentType, transferProgress, size, fileName, location, key, relay, digest, fastPreflightId, voiceNote, width, height, quote, uploadTimestamp, caption, stickerLocator, blurHash, transformProperties);
+    super(contentType, transferProgress, size, fileName, cdnNumber, location, key, relay, digest, fastPreflightId, voiceNote, width, height, quote, uploadTimestamp, caption, stickerLocator, blurHash, transformProperties);
     this.attachmentId = attachmentId;
     this.hasData      = hasData;
     this.hasThumbnail = hasThumbnail;

app/src/main/java/org/thoughtcrime/securesms/attachments/MmsNotificationAttachment.java

@@ -10,7 +10,7 @@ import org.thoughtcrime.securesms.database.MmsDatabase;
 public class MmsNotificationAttachment extends Attachment {
 
   public MmsNotificationAttachment(int status, long size) {
-    super("application/mms", getTransferStateFromStatus(status), size, null, null, null, null, null, null, false, 0, 0, false, 0, null, null, null, null);
+    super("application/mms", getTransferStateFromStatus(status), size, null, 0, null, null, null, null, null, false, 0, 0, false, 0, null, null, null, null);
   }
 
   @Nullable

app/src/main/java/org/thoughtcrime/securesms/attachments/PointerAttachment.java

@@ -18,13 +18,13 @@ import java.util.List;
 public class PointerAttachment extends Attachment {
 
   private PointerAttachment(@NonNull String contentType, int transferState, long size,
-                            @Nullable String fileName,  @NonNull String location,
+                            @Nullable String fileName, int cdnNumber, @NonNull String location,
                             @Nullable String key, @Nullable String relay,
                             @Nullable byte[] digest, @Nullable String fastPreflightId, boolean voiceNote,
                             int width, int height, long uploadTimestamp, @Nullable String caption, @Nullable StickerLocator stickerLocator,
                             @Nullable BlurHash blurHash)
   {
-    super(contentType, transferState, size, fileName, location, key, relay, digest, fastPreflightId, voiceNote, width, height, false, uploadTimestamp, caption, stickerLocator, blurHash, null);
+    super(contentType, transferState, size, fileName, cdnNumber, location, key, relay, digest, fastPreflightId, voiceNote, width, height, false, uploadTimestamp, caption, stickerLocator, blurHash, null);
   }
 
   @Nullable
@@ -93,7 +93,8 @@ public class PointerAttachment extends Attachment {
                                       AttachmentDatabase.TRANSFER_PROGRESS_PENDING,
                                       pointer.get().asPointer().getSize().or(0),
                                       pointer.get().asPointer().getFileName().orNull(),
-                                      String.valueOf(pointer.get().asPointer().getId()),
+                                      pointer.get().asPointer().getCdnNumber(),
+                                      pointer.get().asPointer().getRemoteId().toString(),
                                       encodedKey, null,
                                       pointer.get().asPointer().getDigest().orNull(),
                                       fastPreflightId,
@@ -114,7 +115,8 @@ public class PointerAttachment extends Attachment {
                                              AttachmentDatabase.TRANSFER_PROGRESS_PENDING,
                                              thumbnail != null ? thumbnail.asPointer().getSize().or(0) : 0,
                                              pointer.getFileName(),
-                                             String.valueOf(thumbnail != null ? thumbnail.asPointer().getId() : 0),
+                                             thumbnail != null ? thumbnail.asPointer().getCdnNumber() : 0,
+                                             thumbnail != null ? thumbnail.asPointer().getRemoteId().toString() : "0",
                                              thumbnail != null && thumbnail.asPointer().getKey() != null ? Base64.encodeBytes(thumbnail.asPointer().getKey()) : null,
                                              null,
                                              thumbnail != null ? thumbnail.asPointer().getDigest().orNull() : null,

app/src/main/java/org/thoughtcrime/securesms/attachments/TombstoneAttachment.java

@@ -16,7 +16,7 @@ import org.thoughtcrime.securesms.database.AttachmentDatabase;
 public class TombstoneAttachment extends Attachment {
 
   public TombstoneAttachment(@NonNull String contentType, boolean quote) {
-    super(contentType, AttachmentDatabase.TRANSFER_PROGRESS_DONE, 0, null, null, null, null, null, null, false, 0, 0, quote, 0, null, null, null, null);
+    super(contentType, AttachmentDatabase.TRANSFER_PROGRESS_DONE, 0, null, 0, null, null, null, null, null, false, 0, 0, quote, 0, null, null, null, null);
   }
 
   @Override

app/src/main/java/org/thoughtcrime/securesms/attachments/UriAttachment.java

@@ -1,11 +1,11 @@
 package org.thoughtcrime.securesms.attachments;
 
 import android.net.Uri;
+
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 
 import org.thoughtcrime.securesms.blurhash.BlurHash;
-import org.thoughtcrime.securesms.database.AttachmentDatabase;
 import org.thoughtcrime.securesms.database.AttachmentDatabase.TransformProperties;
 import org.thoughtcrime.securesms.stickers.StickerLocator;
 
@@ -27,7 +27,7 @@ public class UriAttachment extends Attachment {
                        boolean voiceNote, boolean quote, @Nullable String caption, @Nullable StickerLocator stickerLocator,
                        @Nullable BlurHash blurHash, @Nullable TransformProperties transformProperties)
   {
-    super(contentType, transferState, size, fileName, null, null, null, null, fastPreflightId, voiceNote, width, height, quote, 0, caption, stickerLocator, blurHash, transformProperties);
+    super(contentType, transferState, size, fileName, 0, null, null, null, null, fastPreflightId, voiceNote, width, height, quote, 0, caption, stickerLocator, blurHash, transformProperties);
     this.dataUri      = dataUri;
     this.thumbnailUri = thumbnailUri;
   }

app/src/main/java/org/thoughtcrime/securesms/database/AttachmentDatabase.java

@@ -124,6 +124,7 @@ public class AttachmentDatabase extends Database {
           static final String TRANSFORM_PROPERTIES   = "transform_properties";
           static final String DISPLAY_ORDER          = "display_order";
           static final String UPLOAD_TIMESTAMP       = "upload_timestamp";
+          static final String CDN_NUMBER             = "cdn_number";
 
   public  static final String DIRECTORY              = "parts";
 
@@ -139,13 +140,14 @@ public class AttachmentDatabase extends Database {
 
   private static final String[] PROJECTION = new String[] {ROW_ID,
                                                            MMS_ID, CONTENT_TYPE, NAME, CONTENT_DISPOSITION,
-                                                           CONTENT_LOCATION, DATA, THUMBNAIL, TRANSFER_STATE,
+                                                           CDN_NUMBER, CONTENT_LOCATION, DATA, THUMBNAIL,
-                                                           SIZE, FILE_NAME, THUMBNAIL, THUMBNAIL_ASPECT_RATIO,
+                                                           TRANSFER_STATE, SIZE, FILE_NAME, THUMBNAIL,
-                                                           UNIQUE_ID, DIGEST, FAST_PREFLIGHT_ID, VOICE_NOTE,
+                                                           THUMBNAIL_ASPECT_RATIO, UNIQUE_ID, DIGEST,
-                                                           QUOTE, DATA_RANDOM, THUMBNAIL_RANDOM, WIDTH, HEIGHT,
+                                                           FAST_PREFLIGHT_ID, VOICE_NOTE, QUOTE, DATA_RANDOM,
-                                                           CAPTION, STICKER_PACK_ID, STICKER_PACK_KEY, STICKER_ID,
+                                                           THUMBNAIL_RANDOM, WIDTH, HEIGHT, CAPTION, STICKER_PACK_ID,
-                                                           DATA_HASH, BLUR_HASH, TRANSFORM_PROPERTIES, TRANSFER_FILE,
+                                                           STICKER_PACK_KEY, STICKER_ID, DATA_HASH, BLUR_HASH,
-                                                           DISPLAY_ORDER, UPLOAD_TIMESTAMP };
+                                                           TRANSFORM_PROPERTIES, TRANSFER_FILE, DISPLAY_ORDER,
+                                                           UPLOAD_TIMESTAMP };
 
   public static final String CREATE_TABLE = "CREATE TABLE " + TABLE_NAME + " (" + ROW_ID                 + " INTEGER PRIMARY KEY, " +
                                                                                   MMS_ID                 + " INTEGER, " +
@@ -184,7 +186,8 @@ public class AttachmentDatabase extends Database {
                                                                                   TRANSFORM_PROPERTIES   + " TEXT DEFAULT NULL, " +
                                                                                   TRANSFER_FILE          + " TEXT DEFAULT NULL, " +
                                                                                   DISPLAY_ORDER          + " INTEGER DEFAULT 0, " +
-                                                                                  UPLOAD_TIMESTAMP       + " INTEGER DEFAULT 0);";
+                                                                                  UPLOAD_TIMESTAMP       + " INTEGER DEFAULT 0, " +
+                                                                                  CDN_NUMBER             + " INTEGER DEFAULT 0);";
 
   public static final String[] CREATE_INDEXS = {
     "CREATE INDEX IF NOT EXISTS part_mms_id_index ON " + TABLE_NAME + " (" + MMS_ID + ");",
@@ -532,6 +535,7 @@ public class AttachmentDatabase extends Database {
     }
 
     values.put(TRANSFER_STATE, TRANSFER_PROGRESS_DONE);
+    values.put(CDN_NUMBER, 0);
     values.put(CONTENT_LOCATION, (String)null);
     values.put(CONTENT_DISPOSITION, (String)null);
     values.put(DIGEST, (byte[])null);
@@ -584,6 +588,7 @@ public class AttachmentDatabase extends Database {
     contentValues.put(DATA_RANDOM, sourceDataInfo.random);
 
     contentValues.put(TRANSFER_STATE, sourceAttachment.getTransferState());
+    contentValues.put(CDN_NUMBER, sourceAttachment.getCdnNumber());
     contentValues.put(CONTENT_LOCATION, sourceAttachment.getLocation());
     contentValues.put(DIGEST, sourceAttachment.getDigest());
     contentValues.put(CONTENT_DISPOSITION, sourceAttachment.getKey());
@@ -630,6 +635,7 @@ public class AttachmentDatabase extends Database {
     ContentValues  values   = new ContentValues();
 
     values.put(TRANSFER_STATE, TRANSFER_PROGRESS_DONE);
+    values.put(CDN_NUMBER, attachment.getCdnNumber());
     values.put(CONTENT_LOCATION, attachment.getLocation());
     values.put(DIGEST, attachment.getDigest());
     values.put(CONTENT_DISPOSITION, attachment.getKey());
@@ -1105,6 +1111,7 @@ public class AttachmentDatabase extends Database {
                                               object.getInt(TRANSFER_STATE),
                                               object.getLong(SIZE),
                                               object.getString(FILE_NAME),
+                                              object.getInt(CDN_NUMBER),
                                               object.getString(CONTENT_LOCATION),
                                               object.getString(CONTENT_DISPOSITION),
                                               object.getString(NAME),
@@ -1138,6 +1145,7 @@ public class AttachmentDatabase extends Database {
                                                                 cursor.getInt(cursor.getColumnIndexOrThrow(TRANSFER_STATE)),
                                                                 cursor.getLong(cursor.getColumnIndexOrThrow(SIZE)),
                                                                 cursor.getString(cursor.getColumnIndexOrThrow(FILE_NAME)),
+                                                                cursor.getInt(cursor.getColumnIndexOrThrow(CDN_NUMBER)),
                                                                 cursor.getString(cursor.getColumnIndexOrThrow(CONTENT_LOCATION)),
                                                                 cursor.getString(cursor.getColumnIndexOrThrow(CONTENT_DISPOSITION)),
                                                                 cursor.getString(cursor.getColumnIndexOrThrow(NAME)),
@@ -1197,6 +1205,7 @@ public class AttachmentDatabase extends Database {
     contentValues.put(CONTENT_TYPE, template.getContentType());
     contentValues.put(TRANSFER_STATE, attachment.getTransferState());
     contentValues.put(UNIQUE_ID, uniqueId);
+    contentValues.put(CDN_NUMBER, useTemplateUpload ? template.getCdnNumber() : attachment.getCdnNumber());
     contentValues.put(CONTENT_LOCATION, useTemplateUpload ? template.getLocation() : attachment.getLocation());
     contentValues.put(DIGEST, useTemplateUpload ? template.getDigest() : attachment.getDigest());
     contentValues.put(CONTENT_DISPOSITION, useTemplateUpload ? template.getKey() : attachment.getKey());

app/src/main/java/org/thoughtcrime/securesms/database/GroupDatabase.java

@@ -282,7 +282,7 @@ public final class GroupDatabase extends Database {
     contentValues.put(MEMBERS, RecipientId.toSerializedList(members));
 
     if (avatar != null) {
-      contentValues.put(AVATAR_ID, avatar.getId());
+      contentValues.put(AVATAR_ID, avatar.getRemoteId().getV2().get());
       contentValues.put(AVATAR_KEY, avatar.getKey());
       contentValues.put(AVATAR_CONTENT_TYPE, avatar.getContentType());
       contentValues.put(AVATAR_DIGEST, avatar.getDigest().orNull());
@@ -326,7 +326,7 @@ public final class GroupDatabase extends Database {
     if (title != null) contentValues.put(TITLE, title);
 
     if (avatar != null) {
-      contentValues.put(AVATAR_ID, avatar.getId());
+      contentValues.put(AVATAR_ID, avatar.getRemoteId().getV2().get());
       contentValues.put(AVATAR_CONTENT_TYPE, avatar.getContentType());
       contentValues.put(AVATAR_KEY, avatar.getKey());
       contentValues.put(AVATAR_DIGEST, avatar.getDigest().orNull());

app/src/main/java/org/thoughtcrime/securesms/database/MediaDatabase.java

@@ -31,6 +31,7 @@ public class MediaDatabase extends Database {
         + AttachmentDatabase.TABLE_NAME + "." + AttachmentDatabase.FILE_NAME + ", "
         + AttachmentDatabase.TABLE_NAME + "." + AttachmentDatabase.DATA + ", "
         + AttachmentDatabase.TABLE_NAME + "." + AttachmentDatabase.THUMBNAIL + ", "
+        + AttachmentDatabase.TABLE_NAME + "." + AttachmentDatabase.CDN_NUMBER + ", "
         + AttachmentDatabase.TABLE_NAME + "." + AttachmentDatabase.CONTENT_LOCATION + ", "
         + AttachmentDatabase.TABLE_NAME + "." + AttachmentDatabase.CONTENT_DISPOSITION + ", "
         + AttachmentDatabase.TABLE_NAME + "." + AttachmentDatabase.DIGEST + ", "

app/src/main/java/org/thoughtcrime/securesms/database/MmsDatabase.java

@@ -198,6 +198,7 @@ public class MmsDatabase extends MessagingDatabase {
           "'" + AttachmentDatabase.DATA + "', " + AttachmentDatabase.TABLE_NAME + "." + AttachmentDatabase.DATA + ", " +
           "'" + AttachmentDatabase.THUMBNAIL + "', " + AttachmentDatabase.TABLE_NAME + "." + AttachmentDatabase.THUMBNAIL + ", " +
           "'" + AttachmentDatabase.CONTENT_TYPE + "', " + AttachmentDatabase.TABLE_NAME + "." + AttachmentDatabase.CONTENT_TYPE + ", " +
+          "'" + AttachmentDatabase.CDN_NUMBER + "', " + AttachmentDatabase.TABLE_NAME + "." + AttachmentDatabase.CDN_NUMBER + ", " +
           "'" + AttachmentDatabase.CONTENT_LOCATION + "', " + AttachmentDatabase.TABLE_NAME + "." + AttachmentDatabase.CONTENT_LOCATION + ", " +
           "'" + AttachmentDatabase.FAST_PREFLIGHT_ID + "', " + AttachmentDatabase.TABLE_NAME + "." + AttachmentDatabase.FAST_PREFLIGHT_ID + "," +
           "'" + AttachmentDatabase.VOICE_NOTE + "', " + AttachmentDatabase.TABLE_NAME + "." + AttachmentDatabase.VOICE_NOTE + "," +

app/src/main/java/org/thoughtcrime/securesms/database/MmsSmsDatabase.java

@@ -346,6 +346,7 @@ public class MmsSmsDatabase extends Database {
                                   "'" + AttachmentDatabase.DATA + "', " + AttachmentDatabase.TABLE_NAME + "." + AttachmentDatabase.DATA + ", " +
                                   "'" + AttachmentDatabase.THUMBNAIL + "', " + AttachmentDatabase.TABLE_NAME + "." + AttachmentDatabase.THUMBNAIL + ", " +
                                   "'" + AttachmentDatabase.CONTENT_TYPE + "', " + AttachmentDatabase.TABLE_NAME + "." + AttachmentDatabase.CONTENT_TYPE + ", " +
+                                  "'" + AttachmentDatabase.CDN_NUMBER + "', " + AttachmentDatabase.TABLE_NAME + "." + AttachmentDatabase.CDN_NUMBER + ", " +
                                   "'" + AttachmentDatabase.CONTENT_LOCATION + "', " + AttachmentDatabase.TABLE_NAME + "." + AttachmentDatabase.CONTENT_LOCATION + ", " +
                                   "'" + AttachmentDatabase.FAST_PREFLIGHT_ID + "', " + AttachmentDatabase.TABLE_NAME + "." + AttachmentDatabase.FAST_PREFLIGHT_ID + ", " +
                                   "'" + AttachmentDatabase.VOICE_NOTE + "', " + AttachmentDatabase.TABLE_NAME + "." + AttachmentDatabase.VOICE_NOTE + ", " +
@@ -455,30 +456,6 @@ public class MmsSmsDatabase extends Database {
     mmsColumnsPresent.add(MmsDatabase.STATUS);
     mmsColumnsPresent.add(MmsDatabase.UNIDENTIFIED);
     mmsColumnsPresent.add(MmsDatabase.NETWORK_FAILURE);
-
-    mmsColumnsPresent.add(AttachmentDatabase.ROW_ID);
-    mmsColumnsPresent.add(AttachmentDatabase.UNIQUE_ID);
-    mmsColumnsPresent.add(AttachmentDatabase.MMS_ID);
-    mmsColumnsPresent.add(AttachmentDatabase.SIZE);
-    mmsColumnsPresent.add(AttachmentDatabase.FILE_NAME);
-    mmsColumnsPresent.add(AttachmentDatabase.DATA);
-    mmsColumnsPresent.add(AttachmentDatabase.THUMBNAIL);
-    mmsColumnsPresent.add(AttachmentDatabase.CONTENT_TYPE);
-    mmsColumnsPresent.add(AttachmentDatabase.CONTENT_LOCATION);
-    mmsColumnsPresent.add(AttachmentDatabase.DIGEST);
-    mmsColumnsPresent.add(AttachmentDatabase.FAST_PREFLIGHT_ID);
-    mmsColumnsPresent.add(AttachmentDatabase.VOICE_NOTE);
-    mmsColumnsPresent.add(AttachmentDatabase.WIDTH);
-    mmsColumnsPresent.add(AttachmentDatabase.HEIGHT);
-    mmsColumnsPresent.add(AttachmentDatabase.QUOTE);
-    mmsColumnsPresent.add(AttachmentDatabase.STICKER_PACK_ID);
-    mmsColumnsPresent.add(AttachmentDatabase.STICKER_PACK_KEY);
-    mmsColumnsPresent.add(AttachmentDatabase.STICKER_ID);
-    mmsColumnsPresent.add(AttachmentDatabase.CAPTION);
-    mmsColumnsPresent.add(AttachmentDatabase.CONTENT_DISPOSITION);
-    mmsColumnsPresent.add(AttachmentDatabase.NAME);
-    mmsColumnsPresent.add(AttachmentDatabase.TRANSFER_STATE);
-    mmsColumnsPresent.add(AttachmentDatabase.ATTACHMENT_JSON_ALIAS);
     mmsColumnsPresent.add(MmsDatabase.QUOTE_ID);
     mmsColumnsPresent.add(MmsDatabase.QUOTE_AUTHOR);
     mmsColumnsPresent.add(MmsDatabase.QUOTE_BODY);

app/src/main/java/org/thoughtcrime/securesms/database/helpers/SQLCipherOpenHelper.java

@@ -126,8 +126,9 @@ public class SQLCipherOpenHelper extends SQLiteOpenHelper {
   private static final int AVATAR_LOCATION_MIGRATION        = 54;
   private static final int GROUPS_V2                        = 55;
   private static final int ATTACHMENT_UPLOAD_TIMESTAMP      = 56;
+  private static final int ATTACHMENT_CDN_NUMBER            = 57;
 
-  private static final int    DATABASE_VERSION = 56;
+  private static final int    DATABASE_VERSION = ATTACHMENT_CDN_NUMBER;
   private static final String DATABASE_NAME    = "signal.db";
 
   private final Context        context;
@@ -863,6 +864,10 @@ public class SQLCipherOpenHelper extends SQLiteOpenHelper {
         db.execSQL("ALTER TABLE part ADD COLUMN upload_timestamp DEFAULT 0");
       }
 
+      if (oldVersion < ATTACHMENT_CDN_NUMBER) {
+        db.execSQL("ALTER TABLE part ADD COLUMN cdn_number INTEGER DEFAULT 0");
+      }
+
       db.setTransactionSuccessful();
     } finally {
       db.endTransaction();

app/src/main/java/org/thoughtcrime/securesms/dependencies/ApplicationDependencies.java

@@ -13,6 +13,7 @@ import org.thoughtcrime.securesms.megaphone.MegaphoneRepository;
 import org.thoughtcrime.securesms.push.SignalServiceNetworkAccess;
 import org.thoughtcrime.securesms.recipients.LiveRecipientCache;
 import org.thoughtcrime.securesms.service.IncomingMessageObserver;
+import org.thoughtcrime.securesms.util.FeatureFlags;
 import org.thoughtcrime.securesms.util.FrameRateTracker;
 import org.thoughtcrime.securesms.util.IasKeyStore;
 import org.thoughtcrime.securesms.util.TextSecurePreferences;
@@ -83,8 +84,11 @@ public class ApplicationDependencies {
     if (messageSender == null) {
       messageSender = provider.provideSignalServiceMessageSender();
     } else {
-      messageSender.setMessagePipe(IncomingMessageObserver.getPipe(), IncomingMessageObserver.getUnidentifiedPipe());
+      messageSender.update(
-      messageSender.setIsMultiDevice(TextSecurePreferences.isMultiDevice(application));
+              IncomingMessageObserver.getPipe(),
+              IncomingMessageObserver.getUnidentifiedPipe(),
+              TextSecurePreferences.isMultiDevice(application),
+              FeatureFlags.attachmentsV3());
     }
 
     return messageSender;

app/src/main/java/org/thoughtcrime/securesms/dependencies/ApplicationDependencyProvider.java

@@ -25,6 +25,7 @@ import org.thoughtcrime.securesms.push.SignalServiceNetworkAccess;
 import org.thoughtcrime.securesms.recipients.LiveRecipientCache;
 import org.thoughtcrime.securesms.service.IncomingMessageObserver;
 import org.thoughtcrime.securesms.util.AlarmSleepTimer;
+import org.thoughtcrime.securesms.util.FeatureFlags;
 import org.thoughtcrime.securesms.util.FrameRateTracker;
 import org.thoughtcrime.securesms.util.TextSecurePreferences;
 import org.whispersystems.libsignal.util.guava.Optional;
@@ -79,6 +80,7 @@ public class ApplicationDependencyProvider implements ApplicationDependencies.Pr
                                             new SignalProtocolStoreImpl(context),
                                             BuildConfig.SIGNAL_AGENT,
                                             TextSecurePreferences.isMultiDevice(context),
+                                            FeatureFlags.attachmentsV3(),
                                             Optional.fromNullable(IncomingMessageObserver.getPipe()),
                                             Optional.fromNullable(IncomingMessageObserver.getUnidentifiedPipe()),
                                             Optional.of(new SecurityEventListener(context)),

app/src/main/java/org/thoughtcrime/securesms/groups/GroupV1MessageProcessor.java

@@ -271,7 +271,7 @@ public final class GroupV1MessageProcessor {
 
     if (group.getAvatar().isPresent() && group.getAvatar().get().isPointer()) {
       builder.setAvatar(AttachmentPointer.newBuilder()
-                                         .setId(group.getAvatar().get().asPointer().getId())
+                                         .setCdnId(group.getAvatar().get().asPointer().getRemoteId().getV2().get())
                                          .setKey(ByteString.copyFrom(group.getAvatar().get().asPointer().getKey()))
                                          .setContentType(group.getAvatar().get().getContentType()));
     }

app/src/main/java/org/thoughtcrime/securesms/jobs/AttachmentDownloadJob.java

@@ -1,8 +1,9 @@
 package org.thoughtcrime.securesms.jobs;
 
+import android.text.TextUtils;
+
 import androidx.annotation.NonNull;
 import androidx.annotation.VisibleForTesting;
-import android.text.TextUtils;
 
 import org.greenrobot.eventbus.EventBus;
 import org.thoughtcrime.securesms.attachments.Attachment;
@@ -27,6 +28,7 @@ import org.thoughtcrime.securesms.util.Util;
 import org.whispersystems.libsignal.InvalidMessageException;
 import org.whispersystems.libsignal.util.guava.Optional;
 import org.whispersystems.signalservice.api.SignalServiceMessageReceiver;
+import org.whispersystems.signalservice.api.messages.SignalServiceAttachmentRemoteId;
 import org.whispersystems.signalservice.api.messages.SignalServiceAttachmentPointer;
 import org.whispersystems.signalservice.api.push.exceptions.NonSuccessfulResponseCodeException;
 import org.whispersystems.signalservice.api.push.exceptions.PushNetworkException;
@@ -182,13 +184,8 @@ public class AttachmentDownloadJob extends BaseJob {
     }
 
     try {
-      long   id    = Long.parseLong(attachment.getLocation());
+      final SignalServiceAttachmentRemoteId remoteId = SignalServiceAttachmentRemoteId.from(attachment.getLocation());
-      byte[] key   = Base64.decode(attachment.getKey());
+      final byte[]                          key      = Base64.decode(attachment.getKey());
-      String relay = null;
-
-      if (TextUtils.isEmpty(attachment.getRelay())) {
-        relay = attachment.getRelay();
-      }
 
       if (attachment.getDigest() != null) {
         Log.i(TAG, "Downloading attachment with digest: " + Hex.toString(attachment.getDigest()));
@@ -196,7 +193,7 @@ public class AttachmentDownloadJob extends BaseJob {
         Log.i(TAG, "Downloading attachment with no digest...");
       }
 
-      return new SignalServiceAttachmentPointer(id, null, key,
+      return new SignalServiceAttachmentPointer(attachment.getCdnNumber(), remoteId, null, key,
                                                 Optional.of(Util.toIntExact(attachment.getSize())),
                                                 Optional.absent(),
                                                 0, 0,

app/src/main/java/org/thoughtcrime/securesms/jobs/AvatarDownloadJob.java

@@ -1,7 +1,5 @@
 package org.thoughtcrime.securesms.jobs;
 
-import android.graphics.Bitmap;
-
 import androidx.annotation.NonNull;
 
 import org.thoughtcrime.securesms.database.DatabaseFactory;
@@ -13,14 +11,12 @@ import org.thoughtcrime.securesms.jobmanager.Data;
 import org.thoughtcrime.securesms.jobmanager.Job;
 import org.thoughtcrime.securesms.jobmanager.impl.NetworkConstraint;
 import org.thoughtcrime.securesms.logging.Log;
-import org.thoughtcrime.securesms.mms.AttachmentStreamUriLoader.AttachmentModel;
 import org.thoughtcrime.securesms.profiles.AvatarHelper;
-import org.thoughtcrime.securesms.util.BitmapDecodingException;
-import org.thoughtcrime.securesms.util.BitmapUtil;
 import org.thoughtcrime.securesms.util.Hex;
 import org.whispersystems.libsignal.InvalidMessageException;
 import org.whispersystems.libsignal.util.guava.Optional;
 import org.whispersystems.signalservice.api.SignalServiceMessageReceiver;
+import org.whispersystems.signalservice.api.messages.SignalServiceAttachmentRemoteId;
 import org.whispersystems.signalservice.api.messages.SignalServiceAttachmentPointer;
 import org.whispersystems.signalservice.api.push.exceptions.NonSuccessfulResponseCodeException;
 
@@ -90,7 +86,7 @@ public class AvatarDownloadJob extends BaseJob {
         attachment.deleteOnExit();
 
         SignalServiceMessageReceiver   receiver    = ApplicationDependencies.getSignalServiceMessageReceiver();
-        SignalServiceAttachmentPointer pointer     = new SignalServiceAttachmentPointer(avatarId, contentType, key, Optional.of(0), Optional.absent(), 0, 0, digest, fileName, false, Optional.absent(), Optional.absent(), System.currentTimeMillis());
+        SignalServiceAttachmentPointer pointer     = new SignalServiceAttachmentPointer(0, new SignalServiceAttachmentRemoteId(avatarId), contentType, key, Optional.of(0), Optional.absent(), 0, 0, digest, fileName, false, Optional.absent(), Optional.absent(), System.currentTimeMillis());
         InputStream                    inputStream = receiver.retrieveAttachment(pointer, attachment, AvatarHelper.AVATAR_DOWNLOAD_FAILSAFE_MAX_SIZE);
 
         AvatarHelper.setAvatar(context, record.get().getRecipientId(), inputStream);

app/src/main/java/org/thoughtcrime/securesms/jobs/PushSendJob.java

@@ -2,9 +2,10 @@ package org.thoughtcrime.securesms.jobs;
 
 import android.content.Context;
 import android.graphics.Bitmap;
+import android.text.TextUtils;
+
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
-import android.text.TextUtils;
 
 import com.annimon.stream.Stream;
 
@@ -43,6 +44,7 @@ import org.thoughtcrime.securesms.util.Util;
 import org.whispersystems.libsignal.util.guava.Optional;
 import org.whispersystems.signalservice.api.crypto.UnidentifiedAccessPair;
 import org.whispersystems.signalservice.api.messages.SignalServiceAttachment;
+import org.whispersystems.signalservice.api.messages.SignalServiceAttachmentRemoteId;
 import org.whispersystems.signalservice.api.messages.SignalServiceAttachmentPointer;
 import org.whispersystems.signalservice.api.messages.SignalServiceDataMessage;
 import org.whispersystems.signalservice.api.messages.SignalServiceDataMessage.Preview;
@@ -184,10 +186,11 @@ public abstract class PushSendJob extends SendJob {
     }
 
     try {
-      long   id  = Long.parseLong(attachment.getLocation());
+      final SignalServiceAttachmentRemoteId remoteId = SignalServiceAttachmentRemoteId.from(attachment.getLocation());
-      byte[] key = Base64.decode(attachment.getKey());
+      final byte[]                          key      = Base64.decode(attachment.getKey());
 
-      return new SignalServiceAttachmentPointer(id,
+      return new SignalServiceAttachmentPointer(attachment.getCdnNumber(),
+                                                remoteId,
                                                 attachment.getContentType(),
                                                 key,
                                                 Optional.of(Util.toIntExact(attachment.getSize())),

app/src/main/java/org/thoughtcrime/securesms/push/SignalServiceNetworkAccess.java

@@ -121,6 +121,16 @@ public class SignalServiceNetworkAccess {
     final SignalCdnUrl              omanGoogleCdn           = new SignalCdnUrl("https://www.google.com.om/cdn", SERVICE_REFLECTOR_HOST, trustStore, GMAIL_CONNECTION_SPEC);
     final SignalCdnUrl              qatarGoogleCdn          = new SignalCdnUrl("https://www.google.com.qa/cdn", SERVICE_REFLECTOR_HOST, trustStore, GMAIL_CONNECTION_SPEC);
 
+    final SignalCdnUrl              baseGoogleCdn2          = new SignalCdnUrl("https://www.google.com/cdn2", SERVICE_REFLECTOR_HOST, trustStore, GMAIL_CONNECTION_SPEC);
+    final SignalCdnUrl              baseAndroidCdn2         = new SignalCdnUrl("https://android.clients.google.com/cdn2", SERVICE_REFLECTOR_HOST, trustStore, PLAY_CONNECTION_SPEC);
+    final SignalCdnUrl              mapsOneAndroidCdn2      = new SignalCdnUrl("https://clients3.google.com/cdn2", SERVICE_REFLECTOR_HOST, trustStore, GMAPS_CONNECTION_SPEC);
+    final SignalCdnUrl              mapsTwoAndroidCdn2      = new SignalCdnUrl("https://clients4.google.com/cdn2", SERVICE_REFLECTOR_HOST, trustStore, GMAPS_CONNECTION_SPEC);
+    final SignalCdnUrl              mailAndroidCdn2         = new SignalCdnUrl("https://inbox.google.com/cdn2", SERVICE_REFLECTOR_HOST, trustStore, GMAIL_CONNECTION_SPEC);
+    final SignalCdnUrl              egyptGoogleCdn2         = new SignalCdnUrl("https://www.google.com.eg/cdn2", SERVICE_REFLECTOR_HOST, trustStore, GMAIL_CONNECTION_SPEC);
+    final SignalCdnUrl              uaeGoogleCdn2           = new SignalCdnUrl("https://www.google.ae/cdn2", SERVICE_REFLECTOR_HOST, trustStore, GMAIL_CONNECTION_SPEC);
+    final SignalCdnUrl              omanGoogleCdn2          = new SignalCdnUrl("https://www.google.com.om/cdn2", SERVICE_REFLECTOR_HOST, trustStore, GMAIL_CONNECTION_SPEC);
+    final SignalCdnUrl              qatarGoogleCdn2         = new SignalCdnUrl("https://www.google.com.qa/cdn2", SERVICE_REFLECTOR_HOST, trustStore, GMAIL_CONNECTION_SPEC);
+
     final SignalContactDiscoveryUrl baseGoogleDiscovery     = new SignalContactDiscoveryUrl("https://www.google.com/directory", SERVICE_REFLECTOR_HOST, trustStore, GMAIL_CONNECTION_SPEC);
     final SignalContactDiscoveryUrl baseAndroidDiscovery    = new SignalContactDiscoveryUrl("https://android.clients.google.com/directory", SERVICE_REFLECTOR_HOST, trustStore, PLAY_CONNECTION_SPEC);
     final SignalContactDiscoveryUrl mapsOneAndroidDiscovery = new SignalContactDiscoveryUrl("https://clients3.google.com/directory", SERVICE_REFLECTOR_HOST, trustStore, GMAPS_CONNECTION_SPEC);
@@ -165,6 +175,7 @@ public class SignalServiceNetworkAccess {
     this.censorshipConfiguration = new HashMap<String, SignalServiceConfiguration>() {{
       put(COUNTRY_CODE_EGYPT, new SignalServiceConfiguration(new SignalServiceUrl[] {egyptGoogleService, baseGoogleService, baseAndroidService, mapsOneAndroidService, mapsTwoAndroidService, mailAndroidService},
                                                              new SignalCdnUrl[] {egyptGoogleCdn, baseAndroidCdn, baseGoogleCdn, mapsOneAndroidCdn, mapsTwoAndroidCdn, mailAndroidCdn, mailAndroidCdn},
+                                                             new SignalCdnUrl[] {egyptGoogleCdn2, baseAndroidCdn2, baseGoogleCdn2, mapsOneAndroidCdn2, mapsTwoAndroidCdn2, mailAndroidCdn2, mailAndroidCdn2},
                                                              new SignalContactDiscoveryUrl[] {egyptGoogleDiscovery, baseGoogleDiscovery, baseAndroidDiscovery, mapsOneAndroidDiscovery, mapsTwoAndroidDiscovery, mailAndroidDiscovery},
                                                              new SignalKeyBackupServiceUrl[] {egyptGoogleKbs, baseGoogleKbs, baseAndroidKbs, mapsOneAndroidKbs, mapsTwoAndroidKbs, mailAndroidKbs},
                                                              new SignalStorageUrl[] {egyptGoogleStorage, baseGoogleStorage, baseAndroidStorage, mapsOneAndroidStorage, mapsTwoAndroidStorage, mailAndroidStorage},
@@ -174,6 +185,7 @@ public class SignalServiceNetworkAccess {
 
       put(COUNTRY_CODE_UAE, new SignalServiceConfiguration(new SignalServiceUrl[] {uaeGoogleService, baseAndroidService, baseGoogleService, mapsOneAndroidService, mapsTwoAndroidService, mailAndroidService},
                                                            new SignalCdnUrl[] {uaeGoogleCdn, baseAndroidCdn, baseGoogleCdn, mapsOneAndroidCdn, mapsTwoAndroidCdn, mailAndroidCdn},
+                                                           new SignalCdnUrl[] {uaeGoogleCdn2, baseAndroidCdn2, baseGoogleCdn2, mapsOneAndroidCdn2, mapsTwoAndroidCdn2, mailAndroidCdn2},
                                                            new SignalContactDiscoveryUrl[] {uaeGoogleDiscovery, baseGoogleDiscovery, baseAndroidDiscovery, mapsOneAndroidDiscovery, mapsTwoAndroidDiscovery, mailAndroidDiscovery},
                                                            new SignalKeyBackupServiceUrl[] {uaeGoogleKbs, baseGoogleKbs, baseAndroidKbs, mapsOneAndroidKbs, mapsTwoAndroidKbs, mailAndroidKbs},
                                                            new SignalStorageUrl[] {uaeGoogleStorage, baseGoogleStorage, baseAndroidStorage, mapsOneAndroidStorage, mapsTwoAndroidStorage, mailAndroidStorage},
@@ -183,6 +195,7 @@ public class SignalServiceNetworkAccess {
 
       put(COUNTRY_CODE_OMAN, new SignalServiceConfiguration(new SignalServiceUrl[] {omanGoogleService, baseAndroidService, baseGoogleService, mapsOneAndroidService, mapsTwoAndroidService, mailAndroidService},
                                                             new SignalCdnUrl[] {omanGoogleCdn, baseAndroidCdn, baseGoogleCdn, mapsOneAndroidCdn, mapsTwoAndroidCdn, mailAndroidCdn},
+                                                            new SignalCdnUrl[] {omanGoogleCdn2, baseAndroidCdn2, baseGoogleCdn2, mapsOneAndroidCdn2, mapsTwoAndroidCdn2, mailAndroidCdn2},
                                                             new SignalContactDiscoveryUrl[] {omanGoogleDiscovery, baseGoogleDiscovery, baseAndroidDiscovery, mapsOneAndroidDiscovery, mapsTwoAndroidDiscovery, mailAndroidDiscovery},
                                                             new SignalKeyBackupServiceUrl[] {omanGoogleKbs, baseGoogleKbs, baseAndroidKbs, mapsOneAndroidKbs, mapsTwoAndroidKbs, mailAndroidKbs},
                                                             new SignalStorageUrl[] {omanGoogleStorage, baseGoogleStorage, baseAndroidStorage, mapsOneAndroidStorage, mapsTwoAndroidStorage, mailAndroidStorage},
@@ -193,6 +206,7 @@ public class SignalServiceNetworkAccess {
 
       put(COUNTRY_CODE_QATAR, new SignalServiceConfiguration(new SignalServiceUrl[] {qatarGoogleService, baseAndroidService, baseGoogleService, mapsOneAndroidService, mapsTwoAndroidService, mailAndroidService},
                                                              new SignalCdnUrl[] {qatarGoogleCdn, baseAndroidCdn, baseGoogleCdn, mapsOneAndroidCdn, mapsTwoAndroidCdn, mailAndroidCdn},
+                                                             new SignalCdnUrl[] {qatarGoogleCdn2, baseAndroidCdn2, baseGoogleCdn2, mapsOneAndroidCdn2, mapsTwoAndroidCdn2, mailAndroidCdn2},
                                                              new SignalContactDiscoveryUrl[] {qatarGoogleDiscovery, baseGoogleDiscovery, baseAndroidDiscovery, mapsOneAndroidDiscovery, mapsTwoAndroidDiscovery, mailAndroidDiscovery},
                                                              new SignalKeyBackupServiceUrl[] {qatarGoogleKbs, baseGoogleKbs, baseAndroidKbs, mapsOneAndroidKbs, mapsTwoAndroidKbs, mailAndroidKbs},
                                                              new SignalStorageUrl[] {qatarGoogleStorage, baseGoogleStorage, baseAndroidStorage, mapsOneAndroidStorage, mapsTwoAndroidStorage, mailAndroidStorage},
@@ -203,6 +217,7 @@ public class SignalServiceNetworkAccess {
 
     this.uncensoredConfiguration = new SignalServiceConfiguration(new SignalServiceUrl[] {new SignalServiceUrl(BuildConfig.SIGNAL_URL, new SignalServiceTrustStore(context))},
                                                                   new SignalCdnUrl[] {new SignalCdnUrl(BuildConfig.SIGNAL_CDN_URL, new SignalServiceTrustStore(context))},
+                                                                  new SignalCdnUrl[] {new SignalCdnUrl(BuildConfig.SIGNAL_CDN2_URL, new SignalServiceTrustStore(context))},
                                                                   new SignalContactDiscoveryUrl[] {new SignalContactDiscoveryUrl(BuildConfig.SIGNAL_CONTACT_DISCOVERY_URL, new SignalServiceTrustStore(context))},
                                                                   new SignalKeyBackupServiceUrl[] { new SignalKeyBackupServiceUrl(BuildConfig.SIGNAL_KEY_BACKUP_URL, new SignalServiceTrustStore(context)) },
                                                                   new SignalStorageUrl[] {new SignalStorageUrl(BuildConfig.STORAGE_URL, new SignalServiceTrustStore(context))},

app/src/main/java/org/thoughtcrime/securesms/util/FeatureFlags.java

@@ -54,6 +54,7 @@ public final class FeatureFlags {
   private static final String PINS_MEGAPHONE_KILL_SWITCH = "android.pinsMegaphoneKillSwitch";
   private static final String PROFILE_NAMES_MEGAPHONE    = "android.profileNamesMegaphone";
   private static final String STORAGE_SERVICE            = "android.storageService.2";
+  private static final String ATTACHMENTS_V3             = "android.attachmentsV3";
 
   /**
    * We will only store remote values for flags in this set. If you want a flag to be controllable
@@ -66,7 +67,8 @@ public final class FeatureFlags {
       PINS_MEGAPHONE_KILL_SWITCH,
       PROFILE_NAMES_MEGAPHONE,
       MESSAGE_REQUESTS,
-      STORAGE_SERVICE
+      STORAGE_SERVICE,
+      ATTACHMENTS_V3
   );
 
   /**
@@ -88,7 +90,8 @@ public final class FeatureFlags {
    */
   private static final Set<String> HOT_SWAPPABLE = Sets.newHashSet(
       PINS_MEGAPHONE_KILL_SWITCH,
-      STORAGE_SERVICE
+      STORAGE_SERVICE,
+      ATTACHMENTS_V3
   );
 
   /**
@@ -213,6 +216,11 @@ public final class FeatureFlags {
     return getValue(STORAGE_SERVICE, false);
   }
 
+  /** Whether or not we use the attachments v3 form. */
+  public static boolean attachmentsV3() {
+    return getValue(ATTACHMENTS_V3, false);
+  }
+
   /** Only for rendering debug info. */
   public static synchronized @NonNull Map<String, Boolean> getMemoryValues() {
     return new TreeMap<>(REMOTE_VALUES);

libsignal/service/src/main/java/org/whispersystems/signalservice/api/SignalServiceMessagePipe.java

@@ -26,7 +26,8 @@ import org.whispersystems.signalservice.api.profiles.ProfileAndCredential;
 import org.whispersystems.signalservice.api.profiles.SignalServiceProfile;
 import org.whispersystems.signalservice.api.push.SignalServiceAddress;
 import org.whispersystems.signalservice.api.util.CredentialsProvider;
-import org.whispersystems.signalservice.internal.push.AttachmentUploadAttributes;
+import org.whispersystems.signalservice.internal.push.AttachmentV2UploadAttributes;
+import org.whispersystems.signalservice.internal.push.AttachmentV3UploadAttributes;
 import org.whispersystems.signalservice.internal.push.OutgoingPushMessageList;
 import org.whispersystems.signalservice.internal.push.SendMessageResponse;
 import org.whispersystems.signalservice.internal.util.JsonUtil;
@@ -219,7 +220,7 @@ public class SignalServiceMessagePipe {
     }
   }
 
-  public AttachmentUploadAttributes getAttachmentUploadAttributes() throws IOException {
+  public AttachmentV2UploadAttributes getAttachmentV2UploadAttributes() throws IOException {
     try {
       WebSocketRequestMessage requestMessage = WebSocketRequestMessage.newBuilder()
                                                                       .setId(new SecureRandom().nextLong())
@@ -233,7 +234,27 @@ public class SignalServiceMessagePipe {
         throw new IOException("Non-successful response: " + response.first());
       }
 
-      return JsonUtil.fromJson(response.second(), AttachmentUploadAttributes.class);
+      return JsonUtil.fromJson(response.second(), AttachmentV2UploadAttributes.class);
+    } catch (InterruptedException | ExecutionException | TimeoutException e) {
+      throw new IOException(e);
+    }
+  }
+
+  public AttachmentV3UploadAttributes getAttachmentV3UploadAttributes() throws IOException {
+    try {
+      WebSocketRequestMessage requestMessage = WebSocketRequestMessage.newBuilder()
+                                                                      .setId(new SecureRandom().nextLong())
+                                                                      .setVerb("GET")
+                                                                      .setPath("/v3/attachments/form/upload")
+                                                                      .build();
+
+      Pair<Integer, String> response = websocket.sendRequest(requestMessage).get(10, TimeUnit.SECONDS);
+
+      if (response.first() < 200 || response.first() >= 300) {
+        throw new IOException("Non-successful response: " + response.first());
+      }
+
+      return JsonUtil.fromJson(response.second(), AttachmentV3UploadAttributes.class);
     } catch (InterruptedException | ExecutionException | TimeoutException e) {
       throw new IOException(e);
     }

libsignal/service/src/main/java/org/whispersystems/signalservice/api/SignalServiceMessageReceiver.java

@@ -178,7 +178,7 @@ public class SignalServiceMessageReceiver {
   {
     if (!pointer.getDigest().isPresent()) throw new InvalidMessageException("No attachment digest!");
 
-    socket.retrieveAttachment(pointer.getId(), destination, maxSizeBytes, listener);
+    socket.retrieveAttachment(pointer.getCdnNumber(), pointer.getRemoteId(), destination, maxSizeBytes, listener);
     return AttachmentCipherInputStream.createForAttachment(destination, pointer.getSize().or(0), pointer.getKey(), pointer.getDigest().get());
   }
 

libsignal/service/src/main/java/org/whispersystems/signalservice/api/SignalServiceMessageSender.java

@@ -25,6 +25,7 @@ import org.whispersystems.signalservice.api.crypto.UntrustedIdentityException;
 import org.whispersystems.signalservice.api.groupsv2.ClientZkOperations;
 import org.whispersystems.signalservice.api.messages.SendMessageResult;
 import org.whispersystems.signalservice.api.messages.SignalServiceAttachment;
+import org.whispersystems.signalservice.api.messages.SignalServiceAttachmentRemoteId;
 import org.whispersystems.signalservice.api.messages.SignalServiceAttachmentPointer;
 import org.whispersystems.signalservice.api.messages.SignalServiceAttachmentStream;
 import org.whispersystems.signalservice.api.messages.SignalServiceDataMessage;
@@ -50,12 +51,14 @@ import org.whispersystems.signalservice.api.messages.multidevice.ViewOnceOpenMes
 import org.whispersystems.signalservice.api.messages.shared.SharedContact;
 import org.whispersystems.signalservice.api.push.SignalServiceAddress;
 import org.whispersystems.signalservice.api.push.exceptions.AuthorizationFailedException;
+import org.whispersystems.signalservice.api.push.exceptions.NonSuccessfulResponseCodeException;
 import org.whispersystems.signalservice.api.push.exceptions.PushNetworkException;
 import org.whispersystems.signalservice.api.push.exceptions.UnregisteredUserException;
 import org.whispersystems.signalservice.api.util.CredentialsProvider;
 import org.whispersystems.signalservice.internal.configuration.SignalServiceConfiguration;
 import org.whispersystems.signalservice.internal.crypto.PaddingInputStream;
-import org.whispersystems.signalservice.internal.push.AttachmentUploadAttributes;
+import org.whispersystems.signalservice.internal.push.AttachmentV2UploadAttributes;
+import org.whispersystems.signalservice.internal.push.AttachmentV3UploadAttributes;
 import org.whispersystems.signalservice.internal.push.MismatchedDevices;
 import org.whispersystems.signalservice.internal.push.OutgoingPushMessage;
 import org.whispersystems.signalservice.internal.push.OutgoingPushMessageList;
@@ -110,6 +113,7 @@ public class SignalServiceMessageSender {
   private final AtomicReference<Optional<SignalServiceMessagePipe>> pipe;
   private final AtomicReference<Optional<SignalServiceMessagePipe>> unidentifiedPipe;
   private final AtomicBoolean                                       isMultiDevice;
+  private final AtomicBoolean                                       attachmentsV3;
 
   /**
    * Construct a SignalServiceMessageSender.
@@ -127,12 +131,13 @@ public class SignalServiceMessageSender {
                                     SignalProtocolStore store,
                                     String signalAgent,
                                     boolean isMultiDevice,
+                                    boolean attachmentsV3,
                                     Optional<SignalServiceMessagePipe> pipe,
                                     Optional<SignalServiceMessagePipe> unidentifiedPipe,
                                     Optional<EventListener> eventListener,
                                     ClientZkProfileOperations clientZkProfileOperations)
   {
-    this(urls, new StaticCredentialsProvider(uuid, e164, password, null), store, signalAgent, isMultiDevice, pipe, unidentifiedPipe, eventListener, clientZkProfileOperations);
+    this(urls, new StaticCredentialsProvider(uuid, e164, password, null), store, signalAgent, isMultiDevice, attachmentsV3, pipe, unidentifiedPipe, eventListener, clientZkProfileOperations);
   }
 
   public SignalServiceMessageSender(SignalServiceConfiguration urls,
@@ -140,6 +145,7 @@ public class SignalServiceMessageSender {
                                     SignalProtocolStore store,
                                     String signalAgent,
                                     boolean isMultiDevice,
+                                    boolean attachmentsV3,
                                     Optional<SignalServiceMessagePipe> pipe,
                                     Optional<SignalServiceMessagePipe> unidentifiedPipe,
                                     Optional<EventListener> eventListener,
@@ -151,6 +157,7 @@ public class SignalServiceMessageSender {
     this.pipe             = new AtomicReference<>(pipe);
     this.unidentifiedPipe = new AtomicReference<>(unidentifiedPipe);
     this.isMultiDevice    = new AtomicBoolean(isMultiDevice);
+    this.attachmentsV3    = new AtomicBoolean(attachmentsV3);
     this.eventListener    = eventListener;
   }
 
@@ -336,13 +343,11 @@ public class SignalServiceMessageSender {
     socket.cancelInFlightRequests();
   }
 
-  public void setMessagePipe(SignalServiceMessagePipe pipe, SignalServiceMessagePipe unidentifiedPipe) {
+  public void update(SignalServiceMessagePipe pipe, SignalServiceMessagePipe unidentifiedPipe, boolean isMultiDevice, boolean attachmentsV3) {
     this.pipe.set(Optional.fromNullable(pipe));
     this.unidentifiedPipe.set(Optional.fromNullable(unidentifiedPipe));
-  }
-
-  public void setIsMultiDevice(boolean isMultiDevice) {
     this.isMultiDevice.set(isMultiDevice);
+    this.attachmentsV3.set(attachmentsV3);
   }
 
   public SignalServiceAttachmentPointer uploadAttachment(SignalServiceAttachmentStream attachment) throws IOException {
@@ -357,26 +362,35 @@ public class SignalServiceMessageSender {
                                                                  attachment.getListener(),
                                                                  attachment.getCancelationSignal());
 
-    AttachmentUploadAttributes         uploadAttributes = null;
+    if (attachmentsV3.get()) {
+      return uploadAttachmentV3(attachment, attachmentKey, attachmentData);
+    } else {
+      return uploadAttachmentV2(attachment, attachmentKey, attachmentData);
+    }
+  }
+
+  private SignalServiceAttachmentPointer uploadAttachmentV2(SignalServiceAttachmentStream attachment, byte[] attachmentKey, PushAttachmentData attachmentData) throws NonSuccessfulResponseCodeException, PushNetworkException {
+    AttachmentV2UploadAttributes       v2UploadAttributes = null;
     Optional<SignalServiceMessagePipe> localPipe          = pipe.get();
 
     if (localPipe.isPresent()) {
       Log.d(TAG, "Using pipe to retrieve attachment upload attributes...");
       try {
-        uploadAttributes = localPipe.get().getAttachmentUploadAttributes();
+        v2UploadAttributes = localPipe.get().getAttachmentV2UploadAttributes();
       } catch (IOException e) {
         Log.w(TAG, "Failed to retrieve attachment upload attributes using pipe. Falling back...");
       }
     }
 
-    if (uploadAttributes == null) {
+    if (v2UploadAttributes == null) {
       Log.d(TAG, "Not using pipe to retrieve attachment upload attributes...");
-      uploadAttributes = socket.getAttachmentUploadAttributes();
+      v2UploadAttributes = socket.getAttachmentV2UploadAttributes();
     }
 
-    Pair<Long, byte[]> attachmentIdAndDigest = socket.uploadAttachment(attachmentData, uploadAttributes);
+    Pair<Long, byte[]> attachmentIdAndDigest = socket.uploadAttachment(attachmentData, v2UploadAttributes);
 
-    return new SignalServiceAttachmentPointer(attachmentIdAndDigest.first(),
+    return new SignalServiceAttachmentPointer(0,
+                                              new SignalServiceAttachmentRemoteId(attachmentIdAndDigest.first()),
                                               attachment.getContentType(),
                                               attachmentKey,
                                               Optional.of(Util.toIntExact(attachment.getLength())),
@@ -390,6 +404,41 @@ public class SignalServiceMessageSender {
                                               attachment.getUploadTimestamp());
   }
 
+  private SignalServiceAttachmentPointer uploadAttachmentV3(SignalServiceAttachmentStream attachment, byte[] attachmentKey, PushAttachmentData attachmentData) throws IOException {
+    AttachmentV3UploadAttributes       v3UploadAttributes = null;
+    Optional<SignalServiceMessagePipe> localPipe          = pipe.get();
+
+    if (localPipe.isPresent()) {
+      Log.d(TAG, "Using pipe to retrieve attachment upload attributes...");
+      try {
+        v3UploadAttributes = localPipe.get().getAttachmentV3UploadAttributes();
+      } catch (IOException e) {
+        Log.w(TAG, "Failed to retrieve attachment upload attributes using pipe. Falling back...");
+      }
+    }
+
+    if (v3UploadAttributes == null) {
+      Log.d(TAG, "Not using pipe to retrieve attachment upload attributes...");
+      v3UploadAttributes = socket.getAttachmentV3UploadAttributes();
+    }
+
+    byte[] digest = socket.uploadAttachment(attachmentData, v3UploadAttributes);
+    return new SignalServiceAttachmentPointer(v3UploadAttributes.getCdn(),
+                                              new SignalServiceAttachmentRemoteId(v3UploadAttributes.getKey()),
+                                              attachment.getContentType(),
+                                              attachmentKey,
+                                              Optional.of(Util.toIntExact(attachment.getLength())),
+                                              attachment.getPreview(),
+                                              attachment.getWidth(),
+                                              attachment.getHeight(),
+                                              Optional.of(digest),
+                                              attachment.getFileName(),
+                                              attachment.getVoiceNote(),
+                                              attachment.getCaption(),
+                                              attachment.getBlurHash(),
+                                              attachment.getUploadTimestamp());
+  }
+
 
   private void sendMessage(VerifiedMessage message, Optional<UnidentifiedAccessPair> unidentifiedAccess)
       throws IOException, UntrustedIdentityException
@@ -1205,12 +1254,20 @@ public class SignalServiceMessageSender {
 
   private AttachmentPointer createAttachmentPointer(SignalServiceAttachmentPointer attachment) {
     AttachmentPointer.Builder builder = AttachmentPointer.newBuilder()
+                                                         .setCdnNumber(attachment.getCdnNumber())
                                                          .setContentType(attachment.getContentType())
-                                                         .setId(attachment.getId())
                                                          .setKey(ByteString.copyFrom(attachment.getKey()))
                                                          .setDigest(ByteString.copyFrom(attachment.getDigest().get()))
                                                          .setSize(attachment.getSize().get());
 
+    if (attachment.getRemoteId().getV2().isPresent()) {
+      builder.setCdnId(attachment.getRemoteId().getV2().get());
+    }
+
+    if (attachment.getRemoteId().getV3().isPresent()) {
+      builder.setCdnKey(attachment.getRemoteId().getV3().get());
+    }
+
     if (attachment.getFileName().isPresent()) {
       builder.setFileName(attachment.getFileName().get());
     }
@@ -1245,8 +1302,7 @@ public class SignalServiceMessageSender {
   private AttachmentPointer createAttachmentPointer(SignalServiceAttachmentStream attachment)
       throws IOException
   {
-    SignalServiceAttachmentPointer pointer = uploadAttachment(attachment);
+    return createAttachmentPointer(uploadAttachment(attachment));
-    return createAttachmentPointer(pointer);
   }
 
 

libsignal/service/src/main/java/org/whispersystems/signalservice/api/messages/SignalServiceAttachmentPointer.java

@@ -18,7 +18,8 @@ import org.whispersystems.signalservice.api.SignalServiceMessageReceiver;
  */
 public class SignalServiceAttachmentPointer extends SignalServiceAttachment {
 
-  private final long              id;
+  private final int                             cdnNumber;
+  private final SignalServiceAttachmentRemoteId remoteId;
   private final byte[]                          key;
   private final Optional<Integer>               size;
   private final Optional<byte[]>                preview;
@@ -31,15 +32,17 @@ public class SignalServiceAttachmentPointer extends SignalServiceAttachment {
   private final Optional<String>                blurHash;
   private final long                            uploadTimestamp;
 
-  public SignalServiceAttachmentPointer(long id, String contentType, byte[] key,
+  public SignalServiceAttachmentPointer(int cdnNumber, SignalServiceAttachmentRemoteId remoteId,
-                                        Optional<Integer> size, Optional<byte[]> preview,
+                                        String contentType, byte[] key,
-                                        int width, int height,
+                                        Optional<Integer> size, Optional<byte[]> preview, int width,
-                                        Optional<byte[]> digest, Optional<String> fileName,
+                                        int height, Optional<byte[]> digest,
-                                        boolean voiceNote, Optional<String> caption,
+                                        Optional<String> fileName, boolean voiceNote,
-                                        Optional<String> blurHash, long uploadTimestamp)
+                                        Optional<String> caption, Optional<String> blurHash,
+                                        long uploadTimestamp)
   {
     super(contentType);
-    this.id              = id;
+    this.cdnNumber       = cdnNumber;
+    this.remoteId        = remoteId;
     this.key             = key;
     this.size            = size;
     this.preview         = preview;
@@ -53,8 +56,12 @@ public class SignalServiceAttachmentPointer extends SignalServiceAttachment {
     this.uploadTimestamp = uploadTimestamp;
   }
 
-  public long getId() {
+  public int getCdnNumber() {
-    return id;
+    return cdnNumber;
+  }
+
+  public SignalServiceAttachmentRemoteId getRemoteId() {
+    return remoteId;
   }
 
   public byte[] getKey() {

libsignal/service/src/main/java/org/whispersystems/signalservice/api/messages/SignalServiceAttachmentRemoteId.java

@@ -0,0 +1,69 @@
+package org.whispersystems.signalservice.api.messages;
+
+import org.signal.libsignal.metadata.ProtocolInvalidMessageException;
+import org.whispersystems.libsignal.InvalidMessageException;
+import org.whispersystems.libsignal.util.guava.Optional;
+import org.whispersystems.signalservice.internal.push.SignalServiceProtos.AttachmentPointer;
+
+/**
+ * Represents a signal service attachment identifier. This can be either a CDN key or a long, but
+ * not both at once. Attachments V2 used a long as an attachment identifier. This lacks sufficient
+ * entropy to reduce the likelihood of any two uploads going to the same location within a 30-day
+ * window. Attachments V3 uses an opaque string as an attachment identifier which provides more
+ * flexibility in the amount of entropy present.
+ */
+public final class SignalServiceAttachmentRemoteId {
+    private final Optional<Long> v2;
+    private final Optional<String> v3;
+
+    public SignalServiceAttachmentRemoteId(long v2) {
+        this.v2 = Optional.of(v2);
+        this.v3 = Optional.absent();
+    }
+
+    public SignalServiceAttachmentRemoteId(String v3) {
+        this.v2 = Optional.absent();
+        this.v3 = Optional.of(v3);
+    }
+
+    public Optional<Long> getV2() {
+        return v2;
+    }
+
+    public Optional<String> getV3() {
+        return v3;
+    }
+
+    @Override
+    public String toString() {
+        if (v2.isPresent()) {
+            return v2.get().toString();
+        } else {
+            return v3.get();
+        }
+    }
+
+    public static SignalServiceAttachmentRemoteId from(AttachmentPointer attachmentPointer) throws ProtocolInvalidMessageException {
+        switch (attachmentPointer.getAttachmentIdentifierCase()) {
+            case CDNID:
+                return new SignalServiceAttachmentRemoteId(attachmentPointer.getCdnId());
+            case CDNKEY:
+                return new SignalServiceAttachmentRemoteId(attachmentPointer.getCdnKey());
+            case ATTACHMENTIDENTIFIER_NOT_SET:
+                throw new ProtocolInvalidMessageException(new InvalidMessageException("AttachmentPointer CDN location not set"), null, 0);
+        }
+        return null;
+    }
+
+    /**
+     * Guesses that strings which contain values parseable to {@code long} should use an id-based
+     * CDN path. Otherwise, use key-based CDN path.
+     */
+    public static SignalServiceAttachmentRemoteId from(String string) {
+        try {
+            return new SignalServiceAttachmentRemoteId(Long.parseLong(string));
+        } catch (NumberFormatException e) {
+            return new SignalServiceAttachmentRemoteId(string);
+        }
+    }
+}

libsignal/service/src/main/java/org/whispersystems/signalservice/api/messages/SignalServiceContent.java

@@ -562,7 +562,7 @@ public final class SignalServiceContent {
                                                                  Optional.<byte[]>absent());
   }
 
-  private static SignalServiceDataMessage.Quote createQuote(SignalServiceProtos.DataMessage content) {
+  private static SignalServiceDataMessage.Quote createQuote(SignalServiceProtos.DataMessage content) throws ProtocolInvalidMessageException {
     if (!content.hasQuote()) return null;
 
     List<SignalServiceDataMessage.Quote.QuotedAttachment> attachments = new LinkedList<>();
@@ -586,7 +586,7 @@ public final class SignalServiceContent {
     }
   }
 
-  private static List<SignalServiceDataMessage.Preview> createPreviews(SignalServiceProtos.DataMessage content) {
+  private static List<SignalServiceDataMessage.Preview> createPreviews(SignalServiceProtos.DataMessage content) throws ProtocolInvalidMessageException {
     if (content.getPreviewCount() <= 0) return null;
 
     List<SignalServiceDataMessage.Preview> results = new LinkedList<>();
@@ -606,7 +606,7 @@ public final class SignalServiceContent {
     return results;
   }
 
-  private static SignalServiceDataMessage.Sticker createSticker(SignalServiceProtos.DataMessage content) {
+  private static SignalServiceDataMessage.Sticker createSticker(SignalServiceProtos.DataMessage content) throws ProtocolInvalidMessageException {
     if (!content.hasSticker()                ||
         !content.getSticker().hasPackId()    ||
         !content.getSticker().hasPackKey()   ||
@@ -641,7 +641,7 @@ public final class SignalServiceContent {
                         reaction.getTargetSentTimestamp());
   }
 
-  private static List<SharedContact> createSharedContacts(SignalServiceProtos.DataMessage content) {
+  private static List<SharedContact> createSharedContacts(SignalServiceProtos.DataMessage content) throws ProtocolInvalidMessageException {
     if (content.getContactCount() <= 0) return null;
 
     List<SharedContact> results = new LinkedList<>();
@@ -736,8 +736,9 @@ public final class SignalServiceContent {
     return results;
   }
 
-  private static SignalServiceAttachmentPointer createAttachmentPointer(SignalServiceProtos.AttachmentPointer pointer) {
+  private static SignalServiceAttachmentPointer createAttachmentPointer(SignalServiceProtos.AttachmentPointer pointer) throws ProtocolInvalidMessageException {
-    return new SignalServiceAttachmentPointer(pointer.getId(),
+    return new SignalServiceAttachmentPointer(pointer.getCdnNumber(),
+                                              SignalServiceAttachmentRemoteId.from(pointer),
                                               pointer.getContentType(),
                                               pointer.getKey().toByteArray(),
                                               pointer.hasSize() ? Optional.of(pointer.getSize()) : Optional.<Integer>absent(),
@@ -795,7 +796,8 @@ public final class SignalServiceContent {
       if (content.getGroup().hasAvatar()) {
         SignalServiceProtos.AttachmentPointer pointer = content.getGroup().getAvatar();
 
-        avatar = new SignalServiceAttachmentPointer(pointer.getId(),
+        avatar = new SignalServiceAttachmentPointer(pointer.getCdnNumber(),
+                                                    SignalServiceAttachmentRemoteId.from(pointer),
                                                     pointer.getContentType(),
                                                     pointer.getKey().toByteArray(),
                                                     Optional.of(pointer.getSize()),

libsignal/service/src/main/java/org/whispersystems/signalservice/internal/configuration/SignalServiceConfiguration.java

@@ -11,6 +11,7 @@ public final class SignalServiceConfiguration {
 
   private final SignalServiceUrl[]          signalServiceUrls;
   private final SignalCdnUrl[]              signalCdnUrls;
+  private final SignalCdnUrl[]              signalCdn2Urls;
   private final SignalContactDiscoveryUrl[] signalContactDiscoveryUrls;
   private final SignalKeyBackupServiceUrl[] signalKeyBackupServiceUrls;
   private final SignalStorageUrl[]          signalStorageUrls;
@@ -20,6 +21,7 @@ public final class SignalServiceConfiguration {
 
   public SignalServiceConfiguration(SignalServiceUrl[] signalServiceUrls,
                                     SignalCdnUrl[] signalCdnUrls,
+                                    SignalCdnUrl[] signalCdn2Urls,
                                     SignalContactDiscoveryUrl[] signalContactDiscoveryUrls,
                                     SignalKeyBackupServiceUrl[] signalKeyBackupServiceUrls,
                                     SignalStorageUrl[] signalStorageUrls,
@@ -29,6 +31,7 @@ public final class SignalServiceConfiguration {
   {
     this.signalServiceUrls          = signalServiceUrls;
     this.signalCdnUrls              = signalCdnUrls;
+    this.signalCdn2Urls             = signalCdn2Urls;
     this.signalContactDiscoveryUrls = signalContactDiscoveryUrls;
     this.signalKeyBackupServiceUrls = signalKeyBackupServiceUrls;
     this.signalStorageUrls          = signalStorageUrls;
@@ -45,6 +48,10 @@ public final class SignalServiceConfiguration {
     return signalCdnUrls;
   }
 
+  public SignalCdnUrl[] getSignalCdn2Urls() {
+    return signalCdn2Urls;
+  }
+
   public SignalContactDiscoveryUrl[] getSignalContactDiscoveryUrls() {
     return signalContactDiscoveryUrls;
   }

libsignal/service/src/main/java/org/whispersystems/signalservice/internal/push/AttachmentV2UploadAttributes.java

@@ -3,7 +3,7 @@ package org.whispersystems.signalservice.internal.push;
 
 import com.fasterxml.jackson.annotation.JsonProperty;
 
-public class AttachmentUploadAttributes {
+public class AttachmentV2UploadAttributes {
   @JsonProperty
   private String url;
 
@@ -34,7 +34,7 @@ public class AttachmentUploadAttributes {
   @JsonProperty
   private String attachmentIdString;
 
-  public AttachmentUploadAttributes() {}
+  public AttachmentV2UploadAttributes() {}
 
   public String getUrl() {
     return url;

libsignal/service/src/main/java/org/whispersystems/signalservice/internal/push/AttachmentV3UploadAttributes.java

@@ -0,0 +1,38 @@
+package org.whispersystems.signalservice.internal.push;
+
+import com.fasterxml.jackson.annotation.JsonProperty;
+
+import java.util.Map;
+
+public final class AttachmentV3UploadAttributes {
+    @JsonProperty
+    private int cdn;
+
+    @JsonProperty
+    private String key;
+
+    @JsonProperty
+    private Map<String, String> headers;
+
+    @JsonProperty
+    private String signedUploadLocation;
+
+    public AttachmentV3UploadAttributes() {
+    }
+
+    public int getCdn() {
+        return cdn;
+    }
+
+    public String getKey() {
+        return key;
+    }
+
+    public Map<String, String> getHeaders() {
+        return headers;
+    }
+
+    public String getSignedUploadLocation() {
+        return signedUploadLocation;
+    }
+}

libsignal/service/src/main/java/org/whispersystems/signalservice/internal/push/PushServiceSocket.java

@@ -35,6 +35,7 @@ import org.whispersystems.signalservice.FeatureFlags;
 import org.whispersystems.signalservice.api.crypto.UnidentifiedAccess;
 import org.whispersystems.signalservice.api.groupsv2.CredentialResponse;
 import org.whispersystems.signalservice.api.messages.SignalServiceAttachment.ProgressListener;
+import org.whispersystems.signalservice.api.messages.SignalServiceAttachmentRemoteId;
 import org.whispersystems.signalservice.api.messages.calls.TurnServerInfo;
 import org.whispersystems.signalservice.api.messages.multidevice.DeviceInfo;
 import org.whispersystems.signalservice.api.profiles.ProfileAndCredential;
@@ -114,6 +115,7 @@ import okhttp3.Call;
 import okhttp3.ConnectionSpec;
 import okhttp3.Credentials;
 import okhttp3.Dns;
+import okhttp3.HttpUrl;
 import okhttp3.Interceptor;
 import okhttp3.MediaType;
 import okhttp3.MultipartBody;
@@ -159,7 +161,8 @@ public class PushServiceSocket {
   private static final String MESSAGE_PATH              = "/v1/messages/%s";
   private static final String SENDER_ACK_MESSAGE_PATH   = "/v1/messages/%s/%d";
   private static final String UUID_ACK_MESSAGE_PATH     = "/v1/messages/uuid/%s";
-  private static final String ATTACHMENT_PATH           = "/v2/attachments/form/upload";
+  private static final String ATTACHMENT_V2_PATH        = "/v2/attachments/form/upload";
+  private static final String ATTACHMENT_V3_PATH        = "/v3/attachments/form/upload";
 
   private static final String PROFILE_PATH              = "/v1/profile/%s";
   private static final String PROFILE_USERNAME_PATH     = "/v1/profile/username/%s";
@@ -169,7 +172,8 @@ public class PushServiceSocket {
 
   private static final String KBS_AUTH_PATH                  = "/v1/backup/auth";
 
-  private static final String ATTACHMENT_DOWNLOAD_PATH  = "attachments/%d";
+  private static final String ATTACHMENT_KEY_DOWNLOAD_PATH   = "attachments/%s";
+  private static final String ATTACHMENT_ID_DOWNLOAD_PATH    = "attachments/%d";
   private static final String ATTACHMENT_UPLOAD_PATH         = "attachments/";
   private static final String AVATAR_UPLOAD_PATH             = "";
 
@@ -189,6 +193,7 @@ public class PushServiceSocket {
 
   private final ServiceConnectionHolder[]  serviceClients;
   private final ConnectionHolder[]         cdnClients;
+  private final ConnectionHolder[]         cdn2Clients;
   private final ConnectionHolder[]         contactDiscoveryClients;
   private final ConnectionHolder[]         keyBackupServiceClients;
   private final ConnectionHolder[]         storageClients;
@@ -207,6 +212,7 @@ public class PushServiceSocket {
     this.signalAgent               = signalAgent;
     this.serviceClients            = createServiceConnectionHolders(configuration.getSignalServiceUrls(), configuration.getNetworkInterceptors(), configuration.getDns());
     this.cdnClients                = createConnectionHolders(configuration.getSignalCdnUrls(), configuration.getNetworkInterceptors(), configuration.getDns());
+    this.cdn2Clients               = createConnectionHolders(configuration.getSignalCdn2Urls(), configuration.getNetworkInterceptors(), configuration.getDns());
     this.contactDiscoveryClients   = createConnectionHolders(configuration.getSignalContactDiscoveryUrls(), configuration.getNetworkInterceptors(), configuration.getDns());
     this.keyBackupServiceClients   = createConnectionHolders(configuration.getSignalKeyBackupServiceUrls(), configuration.getNetworkInterceptors(), configuration.getDns());
     this.storageClients            = createConnectionHolders(configuration.getSignalStorageUrls(), configuration.getNetworkInterceptors(), configuration.getDns());
@@ -516,17 +522,23 @@ public class PushServiceSocket {
     makeServiceRequest(SIGNED_PREKEY_PATH, "PUT", JsonUtil.toJson(signedPreKeyEntity));
   }
 
-  public void retrieveAttachment(long attachmentId, File destination, long maxSizeBytes, ProgressListener listener)
+  public void retrieveAttachment(int cdnNumber, SignalServiceAttachmentRemoteId cdnPath, File destination, long maxSizeBytes, ProgressListener listener)
       throws NonSuccessfulResponseCodeException, PushNetworkException
   {
-    downloadFromCdn(destination, String.format(Locale.US, ATTACHMENT_DOWNLOAD_PATH, attachmentId), maxSizeBytes, listener);
+    final String path;
+    if (cdnPath.getV2().isPresent()) {
+      path = String.format(Locale.US, ATTACHMENT_ID_DOWNLOAD_PATH, cdnPath.getV2().get());
+    } else {
+      path = String.format(Locale.US, ATTACHMENT_KEY_DOWNLOAD_PATH, cdnPath.getV3().get());
+    }
+    downloadFromCdn(destination, cdnNumber, path, maxSizeBytes, listener);
   }
 
   public void retrieveSticker(File destination, byte[] packId, int stickerId)
       throws NonSuccessfulResponseCodeException, PushNetworkException
   {
     String hexPackId = Hex.toStringCondensed(packId);
-    downloadFromCdn(destination, String.format(Locale.US, STICKER_PATH, hexPackId, stickerId), 1024 * 1024, null);
+    downloadFromCdn(destination, 0, String.format(Locale.US, STICKER_PATH, hexPackId, stickerId), 1024 * 1024, null);
   }
 
   public byte[] retrieveSticker(byte[] packId, int stickerId)
@@ -535,7 +547,7 @@ public class PushServiceSocket {
     String                hexPackId = Hex.toStringCondensed(packId);
     ByteArrayOutputStream output    = new ByteArrayOutputStream();
 
-    downloadFromCdn(output, 0, String.format(Locale.US, STICKER_PATH, hexPackId, stickerId), 1024 * 1024, null);
+    downloadFromCdn(output, 0, 0, String.format(Locale.US, STICKER_PATH, hexPackId, stickerId), 1024 * 1024, null);
 
     return output.toByteArray();
   }
@@ -546,7 +558,7 @@ public class PushServiceSocket {
     String                hexPackId = Hex.toStringCondensed(packId);
     ByteArrayOutputStream output    = new ByteArrayOutputStream();
 
-    downloadFromCdn(output, 0, String.format(STICKER_MANIFEST_PATH, hexPackId), 1024 * 1024, null);
+    downloadFromCdn(output, 0, 0, String.format(STICKER_MANIFEST_PATH, hexPackId), 1024 * 1024, null);
 
     return output.toByteArray();
   }
@@ -611,7 +623,7 @@ public class PushServiceSocket {
   public void retrieveProfileAvatar(String path, File destination, long maxSizeBytes)
       throws NonSuccessfulResponseCodeException, PushNetworkException
   {
-    downloadFromCdn(destination, path, maxSizeBytes, null);
+    downloadFromCdn(destination, 0, path, maxSizeBytes, null);
   }
 
   public void setProfileName(String name) throws NonSuccessfulResponseCodeException, PushNetworkException {
@@ -867,10 +879,20 @@ public class PushServiceSocket {
     }
   }
 
-  public AttachmentUploadAttributes getAttachmentUploadAttributes() throws NonSuccessfulResponseCodeException, PushNetworkException {
+  public AttachmentV2UploadAttributes getAttachmentV2UploadAttributes() throws NonSuccessfulResponseCodeException, PushNetworkException {
-    String response = makeServiceRequest(ATTACHMENT_PATH, "GET", null);
+    String response = makeServiceRequest(ATTACHMENT_V2_PATH, "GET", null);
     try {
-      return JsonUtil.fromJson(response, AttachmentUploadAttributes.class);
+      return JsonUtil.fromJson(response, AttachmentV2UploadAttributes.class);
+    } catch (IOException e) {
+      Log.w(TAG, e);
+      throw new NonSuccessfulResponseCodeException("Unable to parse entity");
+    }
+  }
+
+  public AttachmentV3UploadAttributes getAttachmentV3UploadAttributes() throws NonSuccessfulResponseCodeException, PushNetworkException {
+    String response = makeServiceRequest(ATTACHMENT_V3_PATH, "GET", null);
+    try {
+      return JsonUtil.fromJson(response, AttachmentV3UploadAttributes.class);
     } catch (IOException e) {
       Log.w(TAG, e);
       throw new NonSuccessfulResponseCodeException("Unable to parse entity");
@@ -890,7 +912,7 @@ public class PushServiceSocket {
                        null, null);
   }
 
-  public Pair<Long, byte[]> uploadAttachment(PushAttachmentData attachment, AttachmentUploadAttributes uploadAttributes)
+  public Pair<Long, byte[]> uploadAttachment(PushAttachmentData attachment, AttachmentV2UploadAttributes uploadAttributes)
       throws PushNetworkException, NonSuccessfulResponseCodeException
   {
     long   id     = Long.parseLong(uploadAttributes.getAttachmentId());
@@ -905,20 +927,31 @@ public class PushServiceSocket {
     return new Pair<>(id, digest);
   }
 
-  private void downloadFromCdn(File destination, String path, long maxSizeBytes, ProgressListener listener)
+  public byte[] uploadAttachment(PushAttachmentData attachment, AttachmentV3UploadAttributes uploadAttributes) throws IOException {
+    String resumableUploadUrl = getResumableUploadUrl(uploadAttributes.getSignedUploadLocation(), uploadAttributes.getHeaders());
+    return uploadToCdn2(resumableUploadUrl,
+                        attachment.getData(),
+                        "application/octet-stream",
+                        attachment.getDataSize(),
+                        attachment.getOutputStreamFactory(),
+                        attachment.getListener(),
+                        attachment.getCancelationSignal());
+  }
+
+  private void downloadFromCdn(File destination, int cdnNumber, String path, long maxSizeBytes, ProgressListener listener)
       throws PushNetworkException, NonSuccessfulResponseCodeException
   {
     try (FileOutputStream outputStream = new FileOutputStream(destination, true)) {
-      downloadFromCdn(outputStream, destination.length(), path, maxSizeBytes, listener);
+      downloadFromCdn(outputStream, destination.length(), cdnNumber, path, maxSizeBytes, listener);
     } catch (IOException e) {
       throw new PushNetworkException(e);
     }
   }
 
-  private void downloadFromCdn(OutputStream outputStream, long offset, String path, long maxSizeBytes, ProgressListener listener)
+  private void downloadFromCdn(OutputStream outputStream, long offset, int cdnNumber, String path, long maxSizeBytes, ProgressListener listener)
       throws PushNetworkException, NonSuccessfulResponseCodeException
   {
-    ConnectionHolder connectionHolder = getRandom(cdnClients, random);
+    ConnectionHolder connectionHolder = getRandom(cdnNumber == 2 ? cdn2Clients : cdnClients, random);
     OkHttpClient     okHttpClient     = connectionHolder.getClient()
                                                         .newBuilder()
                                                         .connectTimeout(soTimeoutMillis, TimeUnit.MILLISECONDS)
@@ -1046,6 +1079,107 @@ public class PushServiceSocket {
     }
   }
 
+  private String getResumableUploadUrl(String signedUrl, Map<String, String> headers) throws IOException {
+    ConnectionHolder connectionHolder = getRandom(cdn2Clients, random);
+    OkHttpClient     okHttpClient     = connectionHolder.getClient()
+                                                        .newBuilder()
+                                                        .connectTimeout(soTimeoutMillis, TimeUnit.MILLISECONDS)
+                                                        .readTimeout(soTimeoutMillis, TimeUnit.MILLISECONDS)
+                                                        .build();
+    final HttpUrl endpointUrl = HttpUrl.get(connectionHolder.url);
+    final HttpUrl signedHttpUrl;
+    try {
+      signedHttpUrl = HttpUrl.get(signedUrl);
+    } catch (IllegalArgumentException e) {
+      Log.w(TAG, "Server returned a malformed signed url: " + signedUrl);
+      throw new IOException("Server returned a malformed signed url", e);
+    }
+
+    final HttpUrl.Builder urlBuilder = new HttpUrl.Builder().scheme(endpointUrl.scheme())
+                                                            .host(endpointUrl.host())
+                                                            .port(endpointUrl.port())
+                                                            .encodedPath(endpointUrl.encodedPath())
+                                                            .addEncodedPathSegments(signedHttpUrl.encodedPath().substring(1))
+                                                            .encodedQuery(signedHttpUrl.encodedQuery())
+                                                            .encodedFragment(signedHttpUrl.encodedFragment());
+
+    Request.Builder request = new Request.Builder().url(urlBuilder.build())
+                                                   .post(RequestBody.create(null, ""));
+    for (Map.Entry<String, String> header : headers.entrySet()) {
+      request.header(header.getKey(), header.getValue());
+    }
+
+    if (connectionHolder.getHostHeader().isPresent()) {
+      request.header("host", connectionHolder.getHostHeader().get());
+    }
+
+    Call call = okHttpClient.newCall(request.build());
+
+    synchronized (connections) {
+      connections.add(call);
+    }
+
+    try {
+      Response response;
+
+      try {
+        response = call.execute();
+      } catch (IOException e) {
+        throw new PushNetworkException(e);
+      }
+
+      if (response.isSuccessful()) {
+        return response.header("location");
+      } else {
+        throw new NonSuccessfulResponseCodeException("Response: " + response);
+      }
+    } finally {
+      synchronized (connections) {
+        connections.remove(call);
+      }
+    }
+  }
+
+  private byte[] uploadToCdn2(String resumableUrl, InputStream data, String contentType, long length, OutputStreamFactory outputStreamFactory, ProgressListener progressListener, CancelationSignal cancelationSignal) throws IOException {
+    ConnectionHolder connectionHolder = getRandom(cdn2Clients, random);
+    OkHttpClient     okHttpClient     = connectionHolder.getClient()
+                                                        .newBuilder()
+                                                        .connectTimeout(soTimeoutMillis, TimeUnit.MILLISECONDS)
+                                                        .readTimeout(soTimeoutMillis, TimeUnit.MILLISECONDS)
+                                                        .build();
+
+    DigestingRequestBody file = new DigestingRequestBody(data, outputStreamFactory, contentType, length, progressListener, cancelationSignal);
+    Request.Builder request = new Request.Builder().url(resumableUrl)
+                                                   .put(file);
+
+    if (connectionHolder.getHostHeader().isPresent()) {
+      request.header("host", connectionHolder.getHostHeader().get());
+    }
+
+    Call call = okHttpClient.newCall(request.build());
+
+    synchronized (connections) {
+      connections.add(call);
+    }
+
+    try {
+      Response response;
+
+      try {
+        response = call.execute();
+      } catch (IOException e) {
+        throw new PushNetworkException(e);
+      }
+
+      if (response.isSuccessful()) return file.getTransmittedDigest();
+      else                         throw new NonSuccessfulResponseCodeException("Response: " + response);
+    } finally {
+      synchronized (connections) {
+        connections.remove(call);
+      }
+    }
+  }
+
   private String makeServiceRequest(String urlFragment, String method, String jsonBody)
       throws NonSuccessfulResponseCodeException, PushNetworkException
   {

libsignal/service/src/main/proto/SignalService.proto

@@ -377,7 +377,10 @@ message AttachmentPointer {
     VOICE_MESSAGE = 1;
   }
 
-  optional fixed64 id              = 1;
+  oneof attachment_identifier {
+    fixed64        cdnId           = 1;
+    string         cdnKey          = 15;
+  }
   optional string  contentType     = 2;
   optional bytes   key             = 3;
   optional uint32  size            = 4;
@@ -390,6 +393,8 @@ message AttachmentPointer {
   optional string  caption         = 11;
   optional string  blurHash        = 12;
   optional uint64  uploadTimestamp = 13;
+  optional uint32  cdnNumber       = 14;
+  // Next ID: 16
 }
 
 message GroupContext {