Encrypted Bazaar branches?

[John Arbash Meinel]

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Nicholas Allen wrote:
> Hi,
> 
> I had an idea for something that would be really useful. I think it
> would be great if Bazaar could encrypt a repository so the revisions
> can only be viewed if the user knows the private key. This would allow
> Bazaar to be used as a great backup system to FTP servers. SFTP does
> not solve the safe backup problem because the data is stored
> unencrypted on the server and the root user of that system would
> easily be able to examine the data. It could also work as a form of
> access control to the Bazaar repository. When branching or pushing you
> would have to enter the private key to update or view the server's branch.
> 
> How hard would that be to implement in Bazaar?
> 
> Cheers,
> 
> Nick

IIRC it was proposed as a GSoC project last summer, but not much came out of it.

It wouldn't be terribly hard to do so (especially with 'pack' repositories, as
they are write-once.) Probably the hardest part would be getting the key
management worked out.

You would also need to take some care as to how blocks are encrypted for
efficiency. Specifically, bzr likes to read parts of a pack file, rather than
reading the whole thing. So you would probably want to have encryption that
would allow you to read just sections and decrypt them.

Also, how deep do you need encryption? Do you need to encrypt the revision_ids
and file_ids? or is just having the texts themselves be encrypted enough.

In the end, I would say you need a real document describing what is encrypted,
and what security level you are trying to provide. (What class of attacks are
you preventing, etc.) Otherwise it is just something that "sounds neat" but
unless you really audit the security of it, it is a bit bogus to claim
everything is actually secure.

John
=:->
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