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

[Alex Harper]

> 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?

I can't restore the file (old versions fail as well), all attempts result in
the same CipherException,.

> 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.

> But you regularly run compare -a and it didn't pick up this error before?

I tend to run compare -aq periodically. Unfortunately, I don't log when I do
this, so I don't have an exact date. My guess would be that yes, I have run
compare -aq since the last file change. But I can't say for certain.

> Do you back up your boxbackup stores somehow?

No, this is the only copy of the bbstored account.

> Do you have an older stored
> version of this file to compare against, e.g. in a store backup?

No, my secondary manual backup has rolled off the old versions of the file.
I have the current revision on the client and several revisions in bbackup,
none of which can be restored.

> 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. Is there a
way for me to reassemble the file enough to get a binary diff? I could at
least characterize the corruption for you. 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?

Alex 


--
Alex Harper                                         aharper@foobox.net

"Eternity is a terrible thought. I mean, where's it going to end?"
                                                   - Tom Stoppard