Re-use standard attachments on edit

ts/jobs/helpers/sendNormalMessage.ts

@@ -4,6 +4,7 @@
 import lodash from 'lodash';
 import PQueue from 'p-queue';
 import { ContentHint } from '@signalapp/libsignal-client';
+import Long from 'long';
 
 import * as Errors from '../../types/errors.js';
 import { strictAssert } from '../../util/assert.js';
@@ -33,6 +34,7 @@ import type {
   OutgoingStickerType,
 } from '../../textsecure/SendMessage.js';
 import type {
+  AttachmentDownloadableFromTransitTier,
   AttachmentType,
   UploadedAttachmentType,
 } from '../../types/Attachment.js';
@@ -74,6 +76,11 @@ import {
 } from '../../test-node/util/messageFailures.js';
 import { getMessageIdForLogging } from '../../util/idForLogging.js';
 import { send, sendSyncMessageOnly } from '../../messages/send.js';
+import type { SignalService } from '../../protobuf/index.js';
+import { uuidToBytes } from '../../util/uuidToBytes.js';
+import { fromBase64 } from '../../Bytes.js';
+import { MIMETypeToString } from '../../types/MIME.js';
+import { canReuseExistingTransitCdnPointerForEditedMessage } from '../../util/Attachment.js';
 
 const { isNumber } = lodash;
 
@@ -220,7 +227,12 @@ export async function sendNormalMessage(
       sticker,
       storyMessage,
       storyContext,
-    } = await getMessageSendData({ log, message, targetTimestamp });
+    } = await getMessageSendData({
+      log,
+      message,
+      targetTimestamp,
+      isEditedMessageSend: editedMessageTimestamp != null,
+    });
 
     if (reaction) {
       strictAssert(
@@ -584,12 +596,14 @@ async function getMessageSendData({
   log,
   message,
   targetTimestamp,
+  isEditedMessageSend,
 }: Readonly<{
   log: LoggerType;
   message: MessageModel;
   targetTimestamp: number;
+  isEditedMessageSend: boolean;
 }>): Promise<{
-  attachments: Array<UploadedAttachmentType>;
+  attachments: Array<SignalService.IAttachmentPointer>;
   body: undefined | string;
   contact?: Array<EmbeddedContactWithUploadedAvatar>;
   deletedForEveryoneTimestamp: undefined | number;
@@ -652,15 +666,21 @@ async function getMessageSendData({
     storyMessage,
   ] = await Promise.all([
     uploadQueue.addAll(
-      preUploadAttachments.map(
-        attachment => () =>
-          uploadSingleAttachment({
+      preUploadAttachments.map(attachment => async () => {
+        if (isEditedMessageSend) {
+          if (canReuseExistingTransitCdnPointerForEditedMessage(attachment)) {
+            return convertAttachmentToPointer(attachment);
+          }
+          log.error('Unable to reuse attachment pointer for edited message');
+        }
+
+        return uploadSingleAttachment({
           attachment,
           log,
           message,
           targetTimestamp,
+        });
       })
-      )
     ),
     uploadQueue.add(async () =>
       maybeLongAttachment
@@ -1258,3 +1278,47 @@ function didSendToEveryone({
     }
   );
 }
+
+function convertAttachmentToPointer(
+  attachment: AttachmentDownloadableFromTransitTier
+): SignalService.IAttachmentPointer {
+  const {
+    cdnKey,
+    cdnNumber,
+    clientUuid,
+    key,
+    size,
+    digest,
+    incrementalMac,
+    chunkSize,
+    uploadTimestamp,
+    contentType,
+    fileName,
+    flags,
+    width,
+    height,
+    caption,
+    blurHash,
+  } = attachment;
+
+  return {
+    cdnKey,
+    cdnNumber,
+    clientUuid: clientUuid ? uuidToBytes(clientUuid) : undefined,
+    key: fromBase64(key),
+    size,
+    digest: fromBase64(digest),
+    incrementalMac: incrementalMac ? fromBase64(incrementalMac) : undefined,
+    chunkSize,
+    uploadTimestamp: uploadTimestamp
+      ? Long.fromNumber(uploadTimestamp)
+      : undefined,
+    contentType: MIMETypeToString(contentType),
+    fileName,
+    flags,
+    width,
+    height,
+    caption,
+    blurHash,
+  };
+}

ts/textsecure/SendMessage.ts

@@ -189,7 +189,7 @@ export const singleProtoJobDataSchema = z.object({
 export type SingleProtoJobData = z.infer<typeof singleProtoJobDataSchema>;
 
 export type MessageOptionsType = {
-  attachments?: ReadonlyArray<UploadedAttachmentType>;
+  attachments?: ReadonlyArray<Proto.IAttachmentPointer>;
   body?: string;
   bodyRanges?: ReadonlyArray<RawBodyRange>;
   contact?: ReadonlyArray<EmbeddedContactWithUploadedAvatar>;
@@ -215,7 +215,7 @@ export type MessageOptionsType = {
   storyContext?: StoryContextType;
 };
 export type GroupSendOptionsType = {
-  attachments?: ReadonlyArray<UploadedAttachmentType>;
+  attachments?: ReadonlyArray<Proto.IAttachmentPointer>;
   bodyRanges?: ReadonlyArray<RawBodyRange>;
   contact?: ReadonlyArray<EmbeddedContactWithUploadedAvatar>;
   deletedForEveryoneTimestamp?: number;
@@ -235,7 +235,7 @@ export type GroupSendOptionsType = {
 };
 
 class Message {
-  attachments: ReadonlyArray<UploadedAttachmentType>;
+  attachments: ReadonlyArray<Proto.IAttachmentPointer>;
 
   body?: string;
 
@@ -1211,7 +1211,7 @@ export class MessageSender {
     urgent,
     includePniSignatureMessage,
   }: Readonly<{
-    attachments: ReadonlyArray<UploadedAttachmentType> | undefined;
+    attachments: ReadonlyArray<Proto.IAttachmentPointer> | undefined;
     bodyRanges?: ReadonlyArray<RawBodyRange>;
     contact?: ReadonlyArray<EmbeddedContactWithUploadedAvatar>;
     contentHint: number;

ts/types/Attachment.ts

@@ -127,13 +127,11 @@ export type UploadedAttachmentType = Proto.IAttachmentPointer &
   Readonly<{
     // Required fields
     cdnKey: string;
-    iv: Uint8Array;
     key: Uint8Array;
     size: number;
     digest: Uint8Array;
     contentType: string;
     plaintextHash: string;
-    isReencryptableToSameDigest: true;
   }>;
 
 export type AttachmentWithHydratedData = AttachmentType & {

ts/util/Attachment.ts

@@ -60,6 +60,8 @@ const MIN_TIMELINE_IMAGE_HEIGHT = 50;
 const MAX_DISPLAYABLE_IMAGE_WIDTH = 8192;
 const MAX_DISPLAYABLE_IMAGE_HEIGHT = 8192;
 
+const MAX_DURATION_TO_REUSE_ATTACHMENT_CDN_POINTER = 3 * DAY;
+
 // // Incoming message attachment fields
 // {
 //   id: string
@@ -1173,6 +1175,23 @@ export function partitionBodyAndNormalAttachments<
   };
 }
 
+export function canReuseExistingTransitCdnPointerForEditedMessage(
+  attachment: AttachmentType
+): attachment is AttachmentDownloadableFromTransitTier {
+  // In practice, this should always return true, since the timeframe for editing a
+  // message is less than MAX_DURATION_TO_REUSE_ATTACHMENT_CDN_POINTER
+  return (
+    isValidDigest(attachment.digest) &&
+    isValidAttachmentKey(attachment.key) &&
+    attachment.cdnKey != null &&
+    attachment.cdnNumber != null &&
+    isMoreRecentThan(
+      attachment.uploadTimestamp ?? 0,
+      MAX_DURATION_TO_REUSE_ATTACHMENT_CDN_POINTER
+    )
+  );
+}
+
 const MESSAGE_ATTACHMENT_TYPES_NEEDING_THUMBNAILS: Set<MessageAttachmentType> =
   new Set(['attachment', 'sticker']);
 

ts/util/uploadAttachment.ts

@@ -54,7 +54,6 @@ export async function uploadAttachment(
     cdnNumber,
     clientUuid: clientUuid ? uuidToBytes(clientUuid) : undefined,
     key: keys,
-    iv: encrypted.iv,
     size: attachment.data.byteLength,
     digest: encrypted.digest,
     plaintextHash: encrypted.plaintextHash,
@@ -69,7 +68,6 @@ export async function uploadAttachment(
     height,
     caption,
     blurHash,
-    isReencryptableToSameDigest: true,
   };
 }