Re: [Lzip-bug] Tarlz 0.4: Use of 'ustar' format instead of 'posix'; question about future of Tarlz utility

[Antonio Diaz Diaz]

Juan Francisco Cantero Hurtado wrote:
> > I think I have found an unexpected difficulty. It seems that the pax
> > format has a serious flaw not present in the ustar format. The
> > extended records in the pax extended header are not protected by any
> > checksum in spite of containing critical metadata (file size,
> > filename, file time,...). This may lead to several kinds of undetected
> > corruption.
>
> You can use a comment entry for the checksum of the headers or whatever
> you want. Other tar tools will ignore the entry.

Exactly, *other tar tools will ignore the entry*, leading to a 
fragmented format[1] where, depending on how the file was created and on 
what unarchiver is used, the integrity check will be sometimes performed 
and sometimes not.

[1] http://www.nongnu.org/lzip/xz_inadequate.html#fragmented