Merge pull request #6541 from ThomasWaldmann/more-robust-iterator-1.1

borg check improvements (1.1)

src/borg/archive.py

@@ -1591,20 +1591,25 @@ class ArchiveChecker:
                 if state > 0:
                     unpacker.resync()
                 for chunk_id, cdata in zip(items, repository.get_many(items)):
-                    data = self.key.decrypt(chunk_id, cdata)
-                    unpacker.feed(data)
                     try:
+                        data = self.key.decrypt(chunk_id, cdata)
+                        unpacker.feed(data)
                         for item in unpacker:
                             valid, reason = valid_item(item)
                             if valid:
                                 yield Item(internal_dict=item)
                             else:
                                 report('Did not get expected metadata dict when unpacking item metadata (%s)' % reason, chunk_id, i)
+                    except IntegrityError as integrity_error:
+                        # key.decrypt() detected integrity issues.
+                        # maybe the repo gave us a valid cdata, but not for the chunk_id we wanted.
+                        # or the authentication of cdata failed, meaning the encrypted data was corrupted.
+                        report(str(integrity_error), chunk_id, i)
                     except RobustUnpacker.UnpackerCrashed:
                         report('Unpacker crashed while unpacking item metadata, trying to resync...', chunk_id, i)
                         unpacker.resync()
                     except Exception:
-                        report('Exception while unpacking item metadata', chunk_id, i)
+                        report('Exception while decrypting or unpacking item metadata', chunk_id, i)
                         raise
                     i += 1
 
@@ -1638,13 +1643,19 @@ class ArchiveChecker:
                 logger.info('Analyzing archive {} ({}/{})'.format(info.name, i + 1, num_archives))
                 archive_id = info.id
                 if archive_id not in self.chunks:
-                    logger.error('Archive metadata block is missing!')
+                    logger.error('Archive metadata block %s is missing!', bin_to_hex(archive_id))
                     self.error_found = True
                     del self.manifest.archives[info.name]
                     continue
                 mark_as_possibly_superseded(archive_id)
                 cdata = self.repository.get(archive_id)
-                data = self.key.decrypt(archive_id, cdata)
+                try:
+                    data = self.key.decrypt(archive_id, cdata)
+                except IntegrityError as integrity_error:
+                    logger.error('Archive metadata block %s is corrupted: %s', bin_to_hex(archive_id), integrity_error)
+                    self.error_found = True
+                    del self.manifest.archives[info.name]
+                    continue
                 archive = ArchiveItem(internal_dict=msgpack.unpackb(data))
                 if archive.version != 1:
                     raise Exception('Unknown archive metadata version')