Am Dienstag, 19. Mai 2020, 18:21:01 CEST schrieb Ard Biesheuvel: Hi Ard, > > To be honest, this looks like the API is being used incorrectly. Is > this a similar issue to the one Herbert spotted recently with the CTR > code? > > When you say 'leaving the TFM untouched' do you mean the skcipher > request? The TFM should not retain any per-request state in the first > place. > > The skcipher request struct is not meant to retain any state either - > the API simply does not support incremental encryption if the input is > not a multiple of the chunksize. > > Could you give some sample code on how you are using the API in this case? What I am doing technically is to allocate a new tfm and request at the beginning and then reuse the TFM and request. In that sense, I think I violate that constraint. But in order to implement such repetition, I can surely clear / allocate a new TFM. But in order to get that right, I need the resulting IV after the cipher operation. This IV that I get after the cipher operation completes is different between C and CE. Ciao Stephan
