On Tue, Jul 28, 2020 at 05:18:39PM +1000, Herbert Xu wrote: > Crypto skcipher algorithms in general allow chaining to break > large operations into smaller ones based on multiples of the chunk > size. However, some algorithms don't support chaining while others > (such as cts) only support chaining for the leading blocks. > > This patch adds the necessary API support for these algorithms. In > particular, a new request flag CRYPTO_TFM_REQ_MORE is added to allow > chaining for algorithms such as cts that cannot otherwise be chained. > > A new algorithm attribute final_chunksize has also been added to > indicate how many blocks at the end of a request that cannot be > chained and therefore must be withheld if chaining is attempted. > > This attribute can also be used to indicate that no chaining is > allowed. Its value should be set to -1 in that case. Shouldn't chaining be disabled by default? This is inviting bugs where drivers don't implement chaining, but leave final_chunksize unset (0) which apparently indicates that chaining is supported. - Eric
