On Fri, Jan 4, 2019 at 6:20 AM Eric Biggers <ebiggers@xxxxxxxxxx> wrote: > > From: Eric Biggers <ebiggers@xxxxxxxxxx> > > Fix multiple bugs in the OFB implementation: > > 1. It stored the per-request state 'cnt' in the tfm context, which can be > used by multiple threads concurrently (e.g. via AF_ALG). > 2. It didn't support messages not a multiple of the block cipher size, > despite being a stream cipher. > 3. It didn't set cra_blocksize to 1 to indicate it is a stream cipher. > > To fix these, set the 'chunksize' property to the cipher block size to > guarantee that when walking through the scatterlist, a partial block can > only occur at the end. Then change the implementation to XOR a block at > a time at first, then XOR the partial block at the end if needed. This > is the same way CTR and CFB are implemented. As a bonus, this also > improves performance in most cases over the current approach. Well, it certainly looks like my implementation had a lot of room for improvement :-) Thank you for doing this, Eric Reviewed-by: Gilad Ben-Yossef <gilad@xxxxxxxxxxxxx> Gilad -- Gilad Ben-Yossef Chief Coffee Drinker values of β will give rise to dom!
