Re: [PATCH] crypto: caam: do not register AES-XTS mode on LP units

[Horia Geanta Neag]

On 11/5/2016 1:17 AM, Sven Ebenfeld wrote:
> When using AES-XTS on a Wandboard, we receive a Mode error:
> caam_jr 2102000.jr1: 20001311: CCB: desc idx 19: AES: Mode error.
> 
> Due to the Security Reference Manual, the Low Power AES units
s/Due to/According to

> of the i.MX6 do not support the XTS mode. Therefore we should
> try to provide them them in the API.
> 
Rephrase: Therefore we mustn't register XTS implementations to Crypto
API in this case.

> Signed-off-by: Sven Ebenfeld <sven.ebenfeld@xxxxxxxxx>
Reviewed-by: Horia Geantă <horia.geanta@xxxxxxx>

Please send the patch to -stable and mention the offending commit:
Cc: <stable@xxxxxxxxxxxxxxx> # 4.4+
Fixes: c6415a6016bf "crypto: caam - add support for acipher xts(aes)"

Thanks,
Horia

> ---
>  drivers/crypto/caam/caamalg.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/crypto/caam/caamalg.c b/drivers/crypto/caam/caamalg.c
> index 156aad1..f5a63ba 100644
> --- a/drivers/crypto/caam/caamalg.c
> +++ b/drivers/crypto/caam/caamalg.c
> @@ -4583,6 +4583,15 @@ static int __init caam_algapi_init(void)
>  		if (!aes_inst && (alg_sel == OP_ALG_ALGSEL_AES))
>  				continue;
>  
> +		/*
> +		 * Check support for AES modes not available
> +		 * on LP devices.
> +		 */
> +		if ((cha_vid & CHA_ID_LS_AES_MASK) == CHA_ID_LS_AES_LP)
> +			if ((alg->class1_alg_type & OP_ALG_AAI_MASK) ==
> +			     OP_ALG_AAI_XTS)
> +				continue;
> +
>  		t_alg = caam_alg_alloc(alg);
>  		if (IS_ERR(t_alg)) {
>  			err = PTR_ERR(t_alg);
>