Le 20/01/2021 à 23:23, Ard Biesheuvel a écrit :
On Wed, 20 Jan 2021 at 19:59, Christophe Leroy <[email protected]> wrote:Talitos Security Engine AESU considers any input data size that is not a multiple of 16 bytes to be an error. This is not a problem in general, except for Counter mode that is a stream cipher and can have an input of any size. Test Manager for ctr(aes) fails on 4th test vector which has a length of 499 while all previous vectors which have a 16 bytes multiple length succeed. As suggested by Freescale, round up the input data length to the nearest 16 bytes. Fixes: 5e75ae1b3cef ("crypto: talitos - add new crypto modes") Signed-off-by: Christophe Leroy <[email protected]>Doesn't this cause the hardware to write outside the given buffer?
Only the input length is modified. Not the output length. The ERRATA says: The input data length (in the descriptor) can be rounded up to the nearest 16B. Set the data-in length (in the descriptor) to include X bytes of data beyond the payload. Set the data-out length to only output the relevant payload (don't need to output the padding). SEC reads from memory are not destructive, so the extra bytes included in the AES-CTR operation can be whatever bytes are contiguously trailing the payload.
