On Mon, May 03, 2021 at 09:56:40AM +0200, Kestrel seventyfour wrote: > Hi, > > I am trying to update the old ifxdeu driver to pass the crypto mgr tests. > However, I continously fail to pass the split tests and I wonder what to do. > > For example, I successfully pass the test vector 0 here: > https://elixir.bootlin.com/linux/latest/source/crypto/testmgr.h#L16654 > if there is no split. > > But if the text "Single block msg" is split into two 8 byte blocks > (single even aligned splits), which end up as separate skcipher walks > in the driver, the second block is wrong and does not compare > correctly, to what is hardcoded in testmgr.h. Same if I try it with > online aes-ctr encoders in the web. > I have tried doing the xor manually with the aes encoded iv, but I get > the same result as the hardware and if I use the next last iv, I still > do not get the second 8 bytes that are hardcoded in cryptomgr.h. > > Can someone shed a light on it? > Is it valid to compare a crypto result that was done on a single walk > with 16byte with two separate walks on the 8 byte splits (of the > original 16)? Is the cryptomgr test on the split tests expecting that > I concat the two walks into a single one? > If yes, how to do that on the uneven splits with separations like 15 > 16 5 byte sequences, etc., fill up the walk up to full block size and > spill over into the next walk? > The split test cases expect the same output (same sequence of bytes) as the non-split test cases. The only difference is how the data is split up into scatterlist elements. Yes, that means that a single 16-byte block of the keystream may need to be XOR'ed with data from multiple scatterlist elements. Take a look at how other drivers handle this. - Eric
