On 29 December 2016 at 02:23, Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> wrote: > On Wed, Dec 28, 2016 at 07:50:44PM +0000, Ard Biesheuvel wrote: >> >> So about this chunksize, is it ever expected to assume other values >> than 1 (for stream ciphers) or the block size (for block ciphers)? >> Having block size, IV size *and* chunk size fields may be confusing to >> some already, so if the purpose of chunk size can be fulfilled by a >> single 'stream cipher' flag, perhaps we should change that first. > > For users (such as algif) it's much more convenient to have a size > rather than a flag because that's what they need to determine the > minimum size for partial updates. > > For implementors you don't need to specify the chunksize at all > unless you're a stream cipher (or some other case in future where > the minimum partial update size is not equal to your block size). > OK, fair enough. So I will add a field 'walksize' to the skcipher_alg struct in my proposal. I think the walk logic itself needs to change very little, though: we can simply set the walk's chunksize to the skcipher's walksize if it exceeds its chunksize (and walksize % chunksize should be 0 in any case, and walksize should default to the chunksize if not supplied) If this sounds reasonable to you, I will hack something up next week. -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
