[darcs-users] Data Integrity

[Nicolas Pouillard]

Excerpts from Daniel Carrera's message of Thu Apr 09 16:36:14 +0200 2009:
> Nicolas Pouillard wrote:
> > Although making a checksum when tagging is fairly easy and darcs should
> > have an option to insert the hash in the tag description (or make it
> > the default).
> > 
> > I would guess that using the pristine hash for this purpose would be fine,
> > in this case this is as simple as :
> > 
> > darcs tag $(head -n 1 _darcs/hashed_inventory | cut -d: -f2)
> 
> That sounds good. And the 'tag' command could sign the hash. For 
> signatures, Darcs could either use GPG or perhaps better, the Haskell 
> Cryptographic Library: http://www.haskell.org/crypto/
> 
> You could store keys in ~/.darcs/keys so they are not attached to the 
> repository.
> 
> In fact, Darcs could sign all patches, so that tags are not "special". I 
> just took a look at the Darcs 2 format. It looks like it should be easy 
> to add an RSA signature. This is what a patch looks like:

Tags are kind of special. This is due to patch commutation that can change
their representation. But by definition a tag patch constrain all patches
that it depends upon to no longer change. So one can store a hash in there.

-- 
Nicolas Pouillard