Re: [PATCH 1/2] crypto: fix cfb mode decryption

Ard Biesheuvel
2018-10-21T15:19:19Z

(+ James)

On 20 October 2018 at 01:01, Dmitry Eremin-Solenikov
<dbaryshkov@gmail.com> wrote:
> crypto_cfb_decrypt_segment() incorrectly XOR'ed generated keystream with
> IV, rather than with data stream, resulting in incorrect decryption.
> Test vectors will be added in the next patch.
>
> Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
> Cc: stable@vger.kernel.org
> ---
> crypto/cfb.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/crypto/cfb.c b/crypto/cfb.c
> index a0d68c09e1b9..fd4e8500e121 100644
> --- a/crypto/cfb.c
> +++ b/crypto/cfb.c
> @@ -144,7 +144,7 @@ static int crypto_cfb_decrypt_segment(struct skcipher_walk *walk,
>
> do {
> crypto_cfb_encrypt_one(tfm, iv, dst);
> - crypto_xor(dst, iv, bsize);
> + crypto_xor(dst, src, bsize);
> iv = src;
>
> src += bsize;
> --
> 2.19.1
>