net/lib80211: move TKIP handling to ARC4 library code

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@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

2 files changed, 18 insertions, 31 deletions

diff --git a/net/wireless/Kconfig b/net/wireless/Kconfig
index abff3c6a5b50..2cfc5b7800e9 100644
--- a/net/wireless/Kconfig
+++ b/net/wireless/Kconfig
@@ -219,6 +219,7 @@ config LIB80211_CRYPT_CCMP
 
 config LIB80211_CRYPT_TKIP
         tristate
+        select CRYPTO_LIB_ARC4
 
 config LIB80211_DEBUG
         bool "lib80211 debugging messages"
diff --git a/net/wireless/lib80211_crypt_tkip.c b/net/wireless/lib80211_crypt_tkip.c
index 11eaa5956f00..0fd155c4e0a6 100644
--- a/net/wireless/lib80211_crypt_tkip.c
+++ b/net/wireless/lib80211_crypt_tkip.c
@@ -13,6 +13,7 @@
 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
 
 #include <linux/err.h>
+#include <linux/fips.h>
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/slab.h>
@@ -29,6 +30,7 @@
 #include <linux/ieee80211.h>
 #include <net/iw_handler.h>
 
+#include <crypto/arc4.h>
 #include <crypto/hash.h>
 #include <linux/crypto.h>
 #include <linux/crc32.h>
@@ -64,9 +66,9 @@ struct lib80211_tkip_data {
 
         int key_idx;
 
-        struct crypto_cipher *rx_tfm_arc4;
+        struct arc4_ctx rx_ctx_arc4;
+        struct arc4_ctx tx_ctx_arc4;
         struct crypto_shash *rx_tfm_michael;
-        struct crypto_cipher *tx_tfm_arc4;
         struct crypto_shash *tx_tfm_michael;
 
         /* scratch buffers for virt_to_page() (crypto API) */
@@ -93,30 +95,21 @@ static void *lib80211_tkip_init(int key_idx)
 {
         struct lib80211_tkip_data *priv;
 
+        if (fips_enabled)
+                return NULL;
+
         priv = kzalloc(sizeof(*priv), GFP_ATOMIC);
         if (priv == NULL)
                 goto fail;
 
         priv->key_idx = key_idx;
 
-        priv->tx_tfm_arc4 = crypto_alloc_cipher("arc4", 0, 0);
-        if (IS_ERR(priv->tx_tfm_arc4)) {
-                priv->tx_tfm_arc4 = NULL;
-                goto fail;
-        }
-
         priv->tx_tfm_michael = crypto_alloc_shash("michael_mic", 0, 0);
         if (IS_ERR(priv->tx_tfm_michael)) {
                 priv->tx_tfm_michael = NULL;
                 goto fail;
         }
 
-        priv->rx_tfm_arc4 = crypto_alloc_cipher("arc4", 0, 0);
-        if (IS_ERR(priv->rx_tfm_arc4)) {
-                priv->rx_tfm_arc4 = NULL;
-                goto fail;
-        }
-
         priv->rx_tfm_michael = crypto_alloc_shash("michael_mic", 0, 0);
         if (IS_ERR(priv->rx_tfm_michael)) {
                 priv->rx_tfm_michael = NULL;
@@ -128,9 +121,7 @@ static void *lib80211_tkip_init(int key_idx)
       fail:
         if (priv) {
                 crypto_free_shash(priv->tx_tfm_michael);
-                crypto_free_cipher(priv->tx_tfm_arc4);
                 crypto_free_shash(priv->rx_tfm_michael);
-                crypto_free_cipher(priv->rx_tfm_arc4);
                 kfree(priv);
         }
 
@@ -142,11 +133,9 @@ static void lib80211_tkip_deinit(void *priv)
         struct lib80211_tkip_data *_priv = priv;
         if (_priv) {
                 crypto_free_shash(_priv->tx_tfm_michael);
-                crypto_free_cipher(_priv->tx_tfm_arc4);
                 crypto_free_shash(_priv->rx_tfm_michael);
-                crypto_free_cipher(_priv->rx_tfm_arc4);
         }
-        kfree(priv);
+        kzfree(priv);
 }
 
 static inline u16 RotR1(u16 val)
@@ -345,7 +334,6 @@ static int lib80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
         int len;
         u8 rc4key[16], *pos, *icv;
         u32 crc;
-        int i;
 
         if (tkey->flags & IEEE80211_CRYPTO_TKIP_COUNTERMEASURES) {
                 struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)skb->data;
@@ -370,9 +358,9 @@ static int lib80211_tkip_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
         icv[2] = crc >> 16;
         icv[3] = crc >> 24;
 
-        crypto_cipher_setkey(tkey->tx_tfm_arc4, rc4key, 16);
-        for (i = 0; i < len + 4; i++)
-                crypto_cipher_encrypt_one(tkey->tx_tfm_arc4, pos + i, pos + i);
+        arc4_setkey(&tkey->tx_ctx_arc4, rc4key, 16);
+        arc4_crypt(&tkey->tx_ctx_arc4, pos, pos, len + 4);
+
         return 0;
 }
 
@@ -400,7 +388,6 @@ static int lib80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
         u8 icv[4];
         u32 crc;
         int plen;
-        int i;
 
         hdr = (struct ieee80211_hdr *)skb->data;
 
@@ -453,9 +440,8 @@ static int lib80211_tkip_decrypt(struct sk_buff *skb, int hdr_len, void *priv)
 
         plen = skb->len - hdr_len - 12;
 
-        crypto_cipher_setkey(tkey->rx_tfm_arc4, rc4key, 16);
-        for (i = 0; i < plen + 4; i++)
-                crypto_cipher_decrypt_one(tkey->rx_tfm_arc4, pos + i, pos + i);
+        arc4_setkey(&tkey->rx_ctx_arc4, rc4key, 16);
+        arc4_crypt(&tkey->rx_ctx_arc4, pos, pos, plen + 4);
 
         crc = ~crc32_le(~0, pos, plen);
         icv[0] = crc;
@@ -640,17 +626,17 @@ static int lib80211_tkip_set_key(void *key, int len, u8 * seq, void *priv)
         struct lib80211_tkip_data *tkey = priv;
         int keyidx;
         struct crypto_shash *tfm = tkey->tx_tfm_michael;
-        struct crypto_cipher *tfm2 = tkey->tx_tfm_arc4;
+        struct arc4_ctx *tfm2 = &tkey->tx_ctx_arc4;
         struct crypto_shash *tfm3 = tkey->rx_tfm_michael;
-        struct crypto_cipher *tfm4 = tkey->rx_tfm_arc4;
+        struct arc4_ctx *tfm4 = &tkey->rx_ctx_arc4;
 
         keyidx = tkey->key_idx;
         memset(tkey, 0, sizeof(*tkey));
         tkey->key_idx = keyidx;
         tkey->tx_tfm_michael = tfm;
-        tkey->tx_tfm_arc4 = tfm2;
+        tkey->tx_ctx_arc4 = *tfm2;
         tkey->rx_tfm_michael = tfm3;
-        tkey->rx_tfm_arc4 = tfm4;
+        tkey->rx_ctx_arc4 = *tfm4;
         if (len == TKIP_KEY_LEN) {
                 memcpy(tkey->key, key, TKIP_KEY_LEN);
                 tkey->key_set = 1;