get_uuid.m

- (NSString *)executableUUID {
  const struct mach_header *executableHeader = NULL;
  for (uint32_t i = 0; i < _dyld_image_count(); i++) {
    const struct mach_header *header = _dyld_get_image_header(i);
    if (header->filetype == MH_EXECUTE) {
      executableHeader = header;
      break;
    }
  }
  
  if (!executableHeader)
    return @"";
  
  BOOL is64bit = executableHeader->magic == MH_MAGIC_64 || executableHeader->magic == MH_CIGAM_64;
  uintptr_t cursor = (uintptr_t)executableHeader + (is64bit ? sizeof(struct mach_header_64) : sizeof(struct mach_header));
  const struct segment_command *segmentCommand = NULL;
  for (uint32_t i = 0; i < executableHeader->ncmds; i++, cursor += segmentCommand->cmdsize) {
    segmentCommand = (struct segment_command *)cursor;
    if (segmentCommand->cmd == LC_UUID) {
      const struct uuid_command *uuidCommand = (const struct uuid_command *)segmentCommand;
      const uint8_t *uuid = uuidCommand->uuid;
      return [[NSString stringWithFormat:@"%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X",
               uuid[0], uuid[1], uuid[2], uuid[3],
               uuid[4], uuid[5], uuid[6], uuid[7],
               uuid[8], uuid[9], uuid[10], uuid[11],
               uuid[12], uuid[13], uuid[14], uuid[15]]
              lowercaseString];
    }
  }
  
  return @"";
}