oss-sec mailing list archives
Re: Reproducible Builds for Fedora
From: Dhiru Kholia <dhiru.kholia () gmail com>
Date: Fri, 27 Sep 2013 12:00:54 +0530
On 09/25/13 at 06:55pm, Solar Designer wrote:
Dhiru, all - Ensuring that "objdump -d" has stayed the same between a known-good and another build of a binary is not sufficient to tell that the new build is not trojaned. Changes to other sections (e.g., to embedded data that the program uses or/and to relocations) or/and to the ELF header may be sufficient to introduce meaningful backdoors. Recent research: https://www.usenix.org/conference/woot13/weird-machines-elf-spotlight-underappreciated-metadata "Our proof-of-concept toolkit highlights how important it is that defenders expand their focus beyond the code and data sections of untrusted binaries" [ Dhiru, weren't you there in person? ;-) ]
I was there but the talk was too technical ;)
December 2006 paper saying that a related technique has "been used in the virus world many years prior to this paper": http://uninformed.org/?v=6&a=3&t=sumry Besides ELF being Turing-complete on its own, the ELF header may contain native executable code too: http://www.muppetlabs.com/~breadbox/software/tiny/teensy.html
After some thinking (and after reading Alexander's emails) I think that producing byte-for-byte identical builds is the only sane choice we are left with. I had this "byte-for-byte" clause in my initial version of the proposal but I dropped it, thinking that it was too "ambitious" for an initial proof-of-concept. It was probably a bad decision on my part. That being said, we have started working towards getting byte-for-byte identical builds. -- Dhiru
Current thread:
- Re: Reproducible Builds for Fedora, (continued)
- Re: Reproducible Builds for Fedora Steve Grubb (Sep 25)
- Re: Reproducible Builds for Fedora Nicolas Vigier (Sep 25)
- Re: Reproducible Builds for Fedora Sebastian Krahmer (Sep 25)
- Re: Reproducible Builds for Fedora Solar Designer (Sep 25)
- Re: Reproducible Builds for Fedora Alexander Cherepanov (Sep 26)
- Re: Reproducible Builds for Fedora Steve Grubb (Sep 26)
- Re: Reproducible Builds for Fedora Alexander Cherepanov (Sep 26)
- Re: Reproducible Builds for Fedora Paul Pluzhnikov (Sep 26)
- Re: Reproducible Builds for Fedora Kurt Seifried (Sep 26)
- Re: Reproducible Builds for Fedora Paul Pluzhnikov (Sep 27)
- Re: Reproducible Builds for Fedora Steve Grubb (Sep 25)
- Re: Reproducible Builds for Fedora Dhiru Kholia (Sep 26)
- Re: Reproducible Builds for Fedora Moritz Muehlenhoff (Sep 25)
- Re: Reproducible Builds for Fedora Dhiru Kholia (Sep 26)