Re: Verifiable git archives?

[Michael Haggerty <mhagger@alum.mit.edu>]

On 01/09/2014 09:11 PM, Junio C Hamano wrote:
> Andy Lutomirski <luto@amacapital.net> writes:
> 
>> It's possible, in principle, to shove enough metadata into the output
>> of 'git archive' to allow anyone to verify (without cloning the repo)
>> to verify that the archive is a correct copy of a given commit.  Would
>> this be considered a useful feature?
>>
>> Presumably there would be a 'git untar' command that would report
>> failure if it fails to verify the archive contents.
>>
>> This could be as simple as including copies of the commit object and
>> all relevant tree objects and checking all of the hashes when
>> untarring.
> 
> You only need the object name of the top-level tree.  After "untar"
> the archive into an empty directory, make it a new repository and
> "git add . && git write-tree"---the result should match the
> top-level tree the archive was supposed to contain.
> [...]

This wouldn't work if any files were excluded from the archive using
gitattribute "export-ignore" (or "export-subst", which you already
mentioned in a follow-up email).

Michael

-- 
Michael Haggerty
mhagger@alum.mit.edu
http://softwareswirl.blogspot.com/