On Tue, Jun 11, 2019 at 03:47:46PM +0200, Ard Biesheuvel wrote:
> The crypto API abstraction is not very useful for invoking ciphers
> directly, especially in the case of arc4, which only has a generic
> implementation in C. So let's invoke the library code directly.
>
> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@xxxxxxxxxx>
> ---
> net/wireless/Kconfig | 1 +
> net/wireless/lib80211_crypt_wep.c | 49 +++++---------------
> 2 files changed, 13 insertions(+), 37 deletions(-)
>
> diff --git a/net/wireless/Kconfig b/net/wireless/Kconfig
> index 6310ddede220..6d9c48cea07e 100644
> --- a/net/wireless/Kconfig
> +++ b/net/wireless/Kconfig
> @@ -213,6 +213,7 @@ config LIB80211
>
> config LIB80211_CRYPT_WEP
> tristate
> + select CRYPTO_LIB_ARC4
>
> config LIB80211_CRYPT_CCMP
> tristate
> diff --git a/net/wireless/lib80211_crypt_wep.c b/net/wireless/lib80211_crypt_wep.c
> index 20c1ad63ad44..9a4e4653fe64 100644
> --- a/net/wireless/lib80211_crypt_wep.c
> +++ b/net/wireless/lib80211_crypt_wep.c
> @@ -11,6 +11,7 @@
> */
>
> #include <linux/err.h>
> +#include <linux/fips.h>
> #include <linux/module.h>
> #include <linux/init.h>
> #include <linux/slab.h>
> @@ -22,7 +23,7 @@
>
> #include <net/lib80211.h>
>
> -#include <linux/crypto.h>
> +#include <crypto/arc4.h>
> #include <linux/crc32.h>
>
> MODULE_AUTHOR("Jouni Malinen");
> @@ -35,51 +36,30 @@ struct lib80211_wep_data {
> u8 key[WEP_KEY_LEN + 1];
> u8 key_len;
> u8 key_idx;
> - struct crypto_cipher *tx_tfm;
> - struct crypto_cipher *rx_tfm;
> + struct arc4_ctx tx_ctx;
> + struct arc4_ctx rx_ctx;
> };
>
> static void *lib80211_wep_init(int keyidx)
> {
> struct lib80211_wep_data *priv;
>
> + if (fips_enabled)
> + return NULL;
> +
> priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
> if (priv == NULL)
> - goto fail;
> + return NULL;
> priv->key_idx = keyidx;
>
> - priv->tx_tfm = crypto_alloc_cipher("arc4", 0, 0);
> - if (IS_ERR(priv->tx_tfm)) {
> - priv->tx_tfm = NULL;
> - goto fail;
> - }
> -
> - priv->rx_tfm = crypto_alloc_cipher("arc4", 0, 0);
> - if (IS_ERR(priv->rx_tfm)) {
> - priv->rx_tfm = NULL;
> - goto fail;
> - }
> /* start WEP IV from a random value */
> get_random_bytes(&priv->iv, 4);
>
> return priv;
> -
> - fail:
> - if (priv) {
> - crypto_free_cipher(priv->tx_tfm);
> - crypto_free_cipher(priv->rx_tfm);
> - kfree(priv);
> - }
> - return NULL;
> }
>
> static void lib80211_wep_deinit(void *priv)
> {
> - struct lib80211_wep_data *_priv = priv;
> - if (_priv) {
> - crypto_free_cipher(_priv->tx_tfm);
> - crypto_free_cipher(_priv->rx_tfm);
> - }
> kfree(priv);
> }
How about changing lib80211_wep_deinit() to use kzfree()? As a result of
changing to the ARC4 library, the arc4_ctx is no longer zeroed. Of course it's
not any worse than it was before since the raw key is already in
lib80211_wep_data too, but it really ought to be kzfree()...
- Eric
