[PATCH 09/15] crypto: zynqmp-aes-gcm: Fix setkey operation to select HW keys

[Herbert Xu]

On Wed, Oct 29, 2025 at 03:51:52PM +0530, Harsh Jain wrote:
> Currently keylen 1 is used to select hw key. There are -ve self test
> which can fail for setkey length 1. Update driver to use 4 bytes
> with magic number to select H/W key type.
> 
> Signed-off-by: Harsh Jain <h.jain at amd.com>
> ---
>  drivers/crypto/xilinx/zynqmp-aes-gcm.c | 94 ++++++++++++++++----------
>  1 file changed, 60 insertions(+), 34 deletions(-)

The hardware key support should be registered under the name paes
instead of aes.  Grep for paes in drivers/crypto for examples.

> @@ -218,32 +220,42 @@ static int zynqmp_aes_aead_setkey(struct crypto_aead *aead, const u8 *key,
>  				  unsigned int keylen)
>  {
>  	struct crypto_tfm *tfm = crypto_aead_tfm(aead);
> -	struct zynqmp_aead_tfm_ctx *tfm_ctx =
> -			(struct zynqmp_aead_tfm_ctx *)crypto_tfm_ctx(tfm);
> +	struct zynqmp_aead_tfm_ctx *tfm_ctx = crypto_tfm_ctx(tfm);
> +	struct xilinx_hwkey_info hwkey;
>  	unsigned char keysrc;
> +	int err;
>  
> -	if (keylen == ZYNQMP_KEY_SRC_SEL_KEY_LEN) {
> -		keysrc = *key;
> +	if (keylen == sizeof(struct xilinx_hwkey_info)) {
> +		memcpy(&hwkey, key, sizeof(struct xilinx_hwkey_info));
> +		if (hwkey.magic != XILINX_KEY_MAGIC)
> +			return -EINVAL;
> +		keysrc = hwkey.type;
>  		if (keysrc == ZYNQMP_AES_KUP_KEY ||
>  		    keysrc == ZYNQMP_AES_DEV_KEY ||
>  		    keysrc == ZYNQMP_AES_PUF_KEY) {
> -			tfm_ctx->keysrc = (enum zynqmp_aead_keysrc)keysrc;
> -		} else {
> -			tfm_ctx->keylen = keylen;
> +			tfm_ctx->keysrc = keysrc;
> +			tfm_ctx->keylen = sizeof(struct xilinx_hwkey_info);
> +			return 0;
>  		}
> -	} else {
> +		return -EINVAL;
> +	}
> +
> +	if (keylen == ZYNQMP_AES_KEY_SIZE && tfm_ctx->keysrc == ZYNQMP_AES_KUP_KEY) {
>  		tfm_ctx->keylen = keylen;
> -		if (keylen == ZYNQMP_AES_KEY_SIZE) {
> -			tfm_ctx->keysrc = ZYNQMP_AES_KUP_KEY;
> -			memcpy(tfm_ctx->key, key, keylen);
> -		}
> +		memcpy(tfm_ctx->key, key, keylen);
> +	} else if (tfm_ctx->keysrc != ZYNQMP_AES_KUP_KEY) {
> +		return -EINVAL;
>  	}
>  
>  	tfm_ctx->fbk_cipher->base.crt_flags &= ~CRYPTO_TFM_REQ_MASK;
>  	tfm_ctx->fbk_cipher->base.crt_flags |= (aead->base.crt_flags &
>  					CRYPTO_TFM_REQ_MASK);
>  
> -	return crypto_aead_setkey(tfm_ctx->fbk_cipher, key, keylen);
> +	err = crypto_aead_setkey(tfm_ctx->fbk_cipher, key, keylen);
> +	if (!err)
> +		tfm_ctx->keylen = keylen;

You can't have a fallback when there is a hardware key.  How did
the fallback not return an error here?

Cheers,
-- 
Email: Herbert Xu <herbert at gondor.apana.org.au>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt