Re: SHA1 collisions found
- From
Joey Hess <id@joeyh.name>
- Date
- Feb 23, 2017, 18:21 UTC
- Message-ID
- <20170223182147.hbsyxsmyijgkqu75@kitenet.net>
- In-Reply-To
- <CA+55aFzFEpi1crykZ33r9f7BsvLt_kiB-CHXOkuCAX=fd4BU-w@mail.gmail.com>
Linus Torvalds wrote:
> What you describe pretty much already requires a pre-image attack, > which the new attack is _not_. > > It's not clear that the "good" object can be anything sane.
Generate a regular commit object; use the entire commit object + NUL as the chosen prefix, and use the identical-prefix collision attack to generate the colliding good/bad objects.
(The size in git's object header is a minor complication. Set the size field to something sufficiently large, and then pad out the colliding objects to that size once they're generated.)
-- see shy jo