[Box Backup] Store corruption not detected or fixed by bbstoreaccounts

[Chris Wilson]

Hi Alex,

On Thu, 22 Jan 2009, Alex Harper wrote:

>> Yes, please keep the file and a log of what happens when you download it.
>
> You mean the current live revision of the file on the client? Or the file
> restored from bbackupquery?

The file on the server.

>> Can you safely leave it on the store for now?
>
> I can for a bit by just stopping the backup. Sadly I do not have enough 
> disk space to archive the whole bbstored account.

Is it deep in directories? Could you copy it and its parent directories to 
a new account? Otherwise can you leave it in the account that it's in now 
for a few days?

>> Let's have a look at the file. Is it big? Can you send it to me? To be
>> honest it sounds like a crypto error, not a diff error. These happen at
>> different layers, so I think the diff patch could only cause a crypto
>> error by corrupting memory.
>
> Unfortunately, the live file contains data I'm not able to share.

Well if you trust Box Backup's crypto then it's safe to send it to me 
anyway :) (as I don't have your keys) but I understand if you don't want 
to.

> Is there a way for me to reassemble the file enough to get a binary 
> diff?

I don't know yet, will have to look into it, maybe tonight.

> I could at least characterize the corruption for you.

I might need to send you test programs to run against it to try to decrypt 
parts of the file and see whether it works or not.

> Or maybe trace which segment of the diff chain is triggering the 
> exception? If you're correct then that individual segment would fail to 
> decrypt, right?

Yes, the other blocks in the file should decrypt OK.

Cheers, Chris.
-- 
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