> On Jul 2, 2015, at 1:42 PM, Sascha Hauer <s.hauer@xxxxxxxxxxxxxx> wrote: > > Hi Philippe, > > On Wed, Jul 01, 2015 at 09:02:28AM +0200, Philippe Leduc wrote: >> Hello, >> >> I have a uImage saved in a memory partition and I am able to boot on >> it with bootm command. I would like to add a digest (like a >> hmac(sha1)) in order to check the integrity of the binary before >> booting on it. >> >> Because my partition is bigger than my uImage, I don't know how to use >> digest on it. >> In fact there are two problems that I don't know how to solve: I can't >> get the size of my file and I can't ask digest to work on COUNT bytes. >> >> For the size problem: I can extract the size of the uImage in binary >> form since this information is present in the uImage header (via >> memcpy), but I don't know how to convert it in a format compatible >> with Hush. >> >> For digest, I can copy the binary in the RAM, but I fear that it is >> longer than working on the flash: it takes 4,8s to memcpy the uImage >> in a RAM file, and less than 3s to bootm on the flash. But >> >> >> Do you know a way to get the size of a file? Or to convert a binary >> size into a "human readable format" for Hush? Or should I develop a >> kind of "stat" utility for barebox? >> Thank you in advance, > > I can't think of a way on the shell to accomplish this. Something that > might come close is uImagefs. You can mount an uImage as a filesystem, > then you can run digest on the individual contents of the image, but not > of the whole image itself. > > Also extracting the size from the image via memcpy and somehow convert > the value to hex, then memcpy the uImage to a file sounds fragile. I > would probably add a option to the uimage command, like -c for copy. > In C it's easy to sanity check the size you read and to verify the > header checksum before doing anything else. You can't do that in shell. uImageFS was design exactly for this case Best Regards, J. > > Sascha > > -- > Pengutronix e.K. | | > Industrial Linux Solutions | http://www.pengutronix.de/ | > Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | > Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | > > _______________________________________________ > barebox mailing list > barebox@xxxxxxxxxxxxxxxxxxx > http://lists.infradead.org/mailman/listinfo/barebox _______________________________________________ barebox mailing list barebox@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
