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Re: push race

From
Nguyen Thai Ngoc Duy <pclouds@gmail.com>
Date
Oct 16, 2012, 05:15 UTC
Message-ID
<CACsJy8AJVAoUHft6+rdOjWCpLWWj3m0NgvFd9pToQRQ5uD8_gg@mail.gmail.com>
In-Reply-To
<20121016045118.GA21359@sigill.intra.peff.net>
On Tue, Oct 16, 2012 at 11:51 AM, Jeff King <peff@peff.net> wrote:
Show 9 quoted lines
>> Its worth nothing that a SHA-1 collision can be identified at the
>> server because the server performs a byte-for-byte compare of both
>> copies of the object to make sure they match exactly in every way. Its
>> not fast, but its safe. :-)
>
> Do we? I thought early versions of git did that, but we did not
> double-check collisions any more for performance reasons. You don't
> happen to remember where that code is, do you (not that it really
> matters, but I am just curious)?

We do. I touched that sha-1 collision code last time I updated index-pack, to support large blobs. We only do that when we receive an object that we already have, which should not happen often unless you're under attack, so little performance impact normally. Search "collision" in index-pack.c

-- 
Duy
Previous: Jeff KingNext: Jeff King
Message 12 of 20 in “push race”
  1. Angelo BorsottiOct 15, 2012
  2. Matthieu MoyOct 15, 2012
  3. Nguyen Thai Ngoc DuyOct 15, 2012
  4. Ævar Arnfjörð BjarmasonOct 15, 2012
  5. demerphqOct 15, 2012
  6. Marc BranchaudOct 15, 2012
  7. Angelo BorsottiOct 15, 2012
  8. Jeff KingOct 15, 2012
  9. Jeff KingOct 15, 2012
  10. Shawn PearceOct 16, 2012
  11. Jeff KingOct 16, 2012
  12. Nguyen Thai Ngoc DuyOct 16, 2012
  13. Jeff KingOct 16, 2012
  14. Nguyen Thai Ngoc DuyOct 16, 2012
  15. Jeff KingOct 16, 2012
  16. Junio C HamanoOct 16, 2012
  17. Jeff KingOct 16, 2012
  18. Junio C HamanoOct 16, 2012
  19. Angelo BorsottiOct 16, 2012
  20. Angelo BorsottiOct 15, 2012

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