Merge pull request #1387 from Bilb/fix-pre-key-errors-bad-mac

fix restoring of session after restore from seed

js/models/conversations.d.ts

@@ -92,7 +92,7 @@ export interface ConversationModel
   makeQuote: any;
   unblock: any;
   deleteContact: any;
-  endSession: any;
+  endSession: () => Promise<void>;
   block: any;
   copyPublicKey: any;
   getAvatar: any;

js/models/conversations.js

@@ -1547,14 +1547,6 @@
     },
     async onSessionResetReceived() {
       await this.setSessionResetStatus(SessionResetEnum.request_received);
-      // send empty message, this will trigger the new session to propagate
-      // to the reset initiator.
-      const user = new libsession.Types.PubKey(this.id);
-
-      const sessionEstablished = new window.libsession.Messages.Outgoing.SessionEstablishedMessage(
-        { timestamp: Date.now() }
-      );
-      await libsession.getMessageQueue().send(user, sessionEstablished);
     },
 
     isSessionResetReceived() {

js/signal_protocol_store.js

@@ -232,8 +232,7 @@
         };
       }
 
-      window.log.error('Failed to fetch prekey:', keyId);
-      return undefined;
+      throw new textsecure.PreKeyMissing();
     },
     async loadPreKeyForContact(contactPubKey) {
       const key = await window.Signal.Data.getPreKeyByRecipient(contactPubKey);

js/views/conversation_view.js

@@ -928,10 +928,6 @@
       }
     },
 
-    endSession() {
-      this.model.endSession();
-    },
-
     setDisappearingMessages(seconds) {
       if (seconds > 0) {
         this.model.updateExpirationTimer(seconds);

libtextsecure/errors.js

@@ -226,6 +226,18 @@
     }
   }
 
+  function PreKeyMissing() {
+    this.name = 'PreKeyMissing';
+
+    Error.call(this, this.name);
+
+    // Maintains proper stack trace, where our error was thrown (only available on V8)
+    //   via https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Error
+    if (Error.captureStackTrace) {
+      Error.captureStackTrace(this);
+    }
+  }
+
   window.textsecure.SendMessageNetworkError = SendMessageNetworkError;
   window.textsecure.IncomingIdentityKeyError = IncomingIdentityKeyError;
   window.textsecure.OutgoingIdentityKeyError = OutgoingIdentityKeyError;
@@ -243,4 +255,5 @@
   window.textsecure.PublicChatError = PublicChatError;
   window.textsecure.PublicTokenError = PublicTokenError;
   window.textsecure.SenderKeyMissing = SenderKeyMissing;
+  window.textsecure.PreKeyMissing = PreKeyMissing;
 })();

libtextsecure/index.d.ts

@@ -21,5 +21,6 @@ export interface LibTextsecure {
   PublicChatError: any;
   PublicTokenError: any;
   SenderKeyMissing: any;
+  PreKeyMissing: any;
   createTaskWithTimeout(task: any, id: any, options?: any): Promise<any>;
 }

ts/components/session/conversation/SessionConversation.tsx

@@ -447,7 +447,7 @@ export class SessionConversation extends React.Component<Props, State> {
       },
       onDeleteContact: () => conversation.deleteContact(),
       onResetSession: () => {
-        conversation.endSession();
+        void conversation.endSession();
       },
 
       onShowSafetyNumber: () => {

ts/receiver/contentMessage.ts

@@ -6,7 +6,10 @@ import { removeFromCache, updateCache } from './cache';
 import { SignalService } from '../protobuf';
 import * as Lodash from 'lodash';
 import * as libsession from '../session';
-import { handleSessionRequestMessage } from './sessionHandling';
+import {
+  handleEndSession,
+  handleSessionRequestMessage,
+} from './sessionHandling';
 import { handlePairingAuthorisationMessage } from './multidevice';
 import { MediumGroupRequestKeysMessage } from '../session/messages/outgoing';
 import { MultiDeviceProtocol, SessionProtocol } from '../session/protocols';
@@ -169,16 +172,16 @@ async function decryptUnidentifiedSender(
         window.log.info(
           'Dropping blocked message with error after sealed sender decryption'
         );
+        await removeFromCache(envelope);
         return null;
       }
 
-      // eslint-disable-next-line no-param-reassign
+      // eslint-disable no-param-reassign
       envelope.source = source.getName();
-      // eslint-disable-next-line no-param-reassign
       envelope.sourceDevice = source.getDeviceId();
-      // eslint-disable-next-line no-param-reassign
       envelope.unidentifiedDeliveryReceived = !originalSource;
-
+      // eslint-enable no-param-reassign
+      await removeFromCache(envelope);
       throw error;
     }
 
@@ -257,6 +260,7 @@ async function doDecrypt(
   }
 }
 
+// tslint:disable-next-line: max-func-body-length
 async function decrypt(
   envelope: EnvelopePlus,
   ciphertext: ArrayBuffer
@@ -309,6 +313,17 @@ async function decrypt(
 
         return;
       }
+    } else if (error instanceof window.textsecure.PreKeyMissing) {
+      const convo = window.ConversationController.get(envelope.source);
+      if (!convo) {
+        window.console.warn(
+          'PreKeyMissing but convo is missing too. Dropping...'
+        );
+        return;
+      }
+      void convo.endSession();
+
+      return;
     }
 
     let errorToThrow = error;

ts/receiver/dataMessage.ts

@@ -286,14 +286,16 @@ export async function handleDataMessage(
     return;
   }
 
-  // tslint:disable-next-line no-bitwise
+  // tslint:disable no-bitwise
   if (
     dataMessage.flags &&
     dataMessage.flags & SignalService.DataMessage.Flags.END_SESSION
   ) {
     await handleEndSession(envelope.source);
-    return;
+    return removeFromCache(envelope);
   }
+  // tslint:enable no-bitwise
+
   const message = await processDecrypted(envelope, dataMessage);
   const ourPubKey = window.textsecure.storage.user.getNumber();
   const senderPubKey = envelope.senderIdentity || envelope.source;
@@ -302,7 +304,7 @@ export async function handleDataMessage(
 
   const { UNPAIRING_REQUEST } = SignalService.DataMessage.Flags;
 
-  // eslint-disable-next-line no-bitwise
+  // tslint:disable-next-line: no-bitwise
   const isUnpairingRequest = Boolean(message.flags & UNPAIRING_REQUEST);
 
   if (isUnpairingRequest) {

ts/receiver/sessionHandling.ts

@@ -14,6 +14,8 @@ export async function handleEndSession(number: string): Promise<void> {
   try {
     const conversation = ConversationController.get(number);
     if (conversation) {
+      // this just marks the conversation as being waiting for a new session
+      // it does trigger a message to be sent. (the message is sent from handleSessionRequestMessage())
       await conversation.onSessionResetReceived();
     } else {
       throw new Error();
@@ -27,7 +29,7 @@ export async function handleSessionRequestMessage(
   envelope: EnvelopePlus,
   preKeyBundleMessage: SignalService.IPreKeyBundleMessage
 ) {
-  const { libsignal, libloki, StringView, textsecure, dcodeIO, log } = window;
+  const { libsignal, StringView, textsecure, dcodeIO, log } = window;
 
   window.console.log(
     `Received SESSION_REQUEST from source: ${envelope.source}`

ts/session/messages/outgoing/content/SessionRequestMessage.ts

@@ -2,6 +2,7 @@ import { ContentMessage } from './ContentMessage';
 import { SignalService } from '../../../../protobuf';
 import { MessageParams } from '../Message';
 import { Constants } from '../../..';
+import * as crypto from 'crypto';
 
 export interface PreKeyBundleType {
   identityKey: Uint8Array;
@@ -19,10 +20,19 @@ interface SessionRequestParams extends MessageParams {
 
 export class SessionRequestMessage extends ContentMessage {
   private readonly preKeyBundle: PreKeyBundleType;
+  private readonly padding: Buffer;
 
   constructor(params: SessionRequestParams) {
     super({ timestamp: params.timestamp, identifier: params.identifier });
     this.preKeyBundle = params.preKeyBundle;
+    // Generate a random int from 1 and 512
+    const buffer = crypto.randomBytes(1);
+
+    // tslint:disable-next-line: no-bitwise
+    const paddingLength = (new Uint8Array(buffer)[0] & 0x1ff) + 1;
+
+    // Generate a random padding buffer of the chosen size
+    this.padding = crypto.randomBytes(paddingLength);
   }
 
   public ttl(): number {
@@ -36,7 +46,7 @@ export class SessionRequestMessage extends ContentMessage {
   protected contentProto(): SignalService.Content {
     const nullMessage = new SignalService.NullMessage({});
     const preKeyBundleMessage = this.getPreKeyBundleMessage();
-
+    nullMessage.padding = this.padding;
     return new SignalService.Content({
       nullMessage,
       preKeyBundleMessage,