Re: [Qemu-devel] [PATCH] virtio-crypto: use the correct length for cipher operation

[Gonglei (Arei)]

Hi Michael,

Ping...



Regards,
-Gonglei


> -----Original Message-----
> From: Gonglei (Arei)
> Sent: Thursday, December 22, 2016 11:37 AM
> To: address@hidden
> Cc: address@hidden; Gonglei (Arei)
> Subject: [PATCH] virtio-crypto: use the correct length for cipher operation
> 
> In some modes of cipher algorithms, the length of destination data
> maybe larger then source data, such as ciphertext stealing (CTS).
> 
> For symmetric algorithms, the length of ciphertext is definitly
> equal to the plaintext for each crypto operation. So we should
> use the src_len instead of dst_len avoid to pass the incorrect
> cryptographical results to the frontend driver.
> 
> Signed-off-by: Gonglei <address@hidden>
> ---
>  hw/virtio/virtio-crypto.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/virtio/virtio-crypto.c b/hw/virtio/virtio-crypto.c
> index 4f11fee..978bb98 100644
> --- a/hw/virtio/virtio-crypto.c
> +++ b/hw/virtio/virtio-crypto.c
> @@ -355,7 +355,7 @@ virtio_crypto_sym_input_data_helper(VirtIODevice
> *vdev,
>          return;
>      }
> 
> -    len = sym_op_info->dst_len;
> +    len = sym_op_info->src_len;
>      /* Save the cipher result */
>      s = iov_from_buf(req->in_iov, req->in_num, 0, sym_op_info->dst, len);
>      if (s != len) {
> --
> 1.8.3.1
>