Hi Melissa,
That definitely is interesting.
I assume you have read
http://blogs.collab.net/subversion/subversion-sha1-collision-problem-statement-prevention-remediation-options
If you do an svnsync to another location and attempt the commit there, does
the problem replicate itself?
--Matt
On Thu, Feb 22, 2018 at 12:30 PM, Myria <myriachan_at_gmail.com> wrote:
> When we try to commit a very specific version of a very specific
> binary file, we get a SHA-1 collision error from the Subversion
> repository:
>
> D:\confidential>svn commit secret.bin -m "Testing broken commit"
> Sending secret.bin
> Transmitting file data .svn: E160000: Commit failed (details follow):
> svn: E160000: SHA1 of reps '604440 34 134255 136680
> c9f4fabc4d093612fece03c339401058
> db11617ef1454332336e00abc311d44bc698f3b3 605556-czmh/_8' and '-1 0
> 134255 136680 c9f4fabc4d093612fece03c339401058
> db11617ef1454332336e00abc311d44bc698f3b3 605556-czmh/_8' matches
> (db11617ef1454332336e00abc311d44bc698f3b3) but contents differ
>
>
> What can cause this? This file is a binary pixel shader compiled from
> a build process. It's most certainly not Google's SHA-1 collision PDF
> files. We also scanned the repository to confirm that nobody has
> committed Google's collision files.
>
> Occam's Razor suggests that something is wrong with our repository or
> Subversion itself, rather than this being a true SHA-1 collision. In
> that case, what is wrong with our repository?
>
> If this really is a SHA-1 collision, it would be major cryptography
> news that someone randomly ran into a second collision without even
> trying. In that case, is there a method by which we could recover the
> two files that supposedly have the same SHA-1? The collision doesn't
> appear to be in the file itself, but in some sort of diff or revision
> output?
>
> Thanks,
>
> Melissa
>
--
"Today, vegetables... Tomorrow, the world!"
Received on 2018-02-22 23:04:34 CET