Re: resuming swsusp twice

[Pavel Machek <pavel@suse.cz>]

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.