Re: resuming swsusp twice

From: Pavel Machek
Date: Sat Jul 16 2005 - 08:59:03 EST


Hi!

> > I of course won't say that this cannot happen, but by design, the
> > swsusp
> > signature is invalidated even before reading the image, so
> > theoretically
> > it should not happen.
>
> Yes, I'd seen that happen on earlier swsusps, so I was quite suprised
> when it blew up like this.
>
> Perhaps the image should be more rigorously checked? I'm wishing that
> it would verify that the header and the image matched, after it finishes
> reading the image. For example, computing the hash
>
> MD5(header || image) (|| denotes "concatenate" in crypto pseudocode.)
>
> and storing that hash in a final trailing block. Additionally, of
> course, as soon as the resume has read the image it should overwrite the
> header; and the header should include jiffies or something along those
> lines to ensure that it won't accidentally have the same contents as the
> previous image's header.
>
> The hash doesn't have to be MD5; even a CRC should suffice I think...

That's quite a lot of complexity... just fix the bug.

Pavel
--
teflon -- maybe it is a trademark, but it should not be.
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