On 8/10/2020 8:03 PM, Eric Biggers wrote: > On Mon, Aug 10, 2020 at 05:33:39PM +0300, Horia Geantă wrote: >> On 8/10/2020 4:45 PM, Herbert Xu wrote: >>> On Mon, Aug 10, 2020 at 10:20:20AM +0000, Van Leeuwen, Pascal wrote: >>>> >>>> With all due respect, but this makes no sense. >>> >>> I agree. This is a lot of churn for no gain. >>> >> I would say the gain is that all skcipher algorithms would behave the same >> when input length equals zero - i.e. treat the request as a no-op. >> >> We can't say "no input" has any meaning to the other skcipher algorithms, >> but the convention is to accept this case and just return 0. >> I don't see why XTS has to be handled differently. >> > > CTS also rejects empty inputs. > > The rule it follows is just that all input lengths >= blocksize are allowed. > Input lengths < blocksize aren't allowed. > Indeed, thanks. What about, for example, CBC? AFAICT cbc(aes) with input length = 0 is valid. Same for CTR (with the note that blocksize = 1) and several other algorithms mentioned in the cover letter. What's the rule in these cases? Thanks, Horia
