mac80211: remove the dependency on crypto_blkcipher
The only thing that using crypto_blkcipher with ecb does over just using
arc4 directly is wrapping the encrypt/decrypt function into a for loop,
looping over each individual character.
To be able to do this, it pulls in around 40 kb worth of unnecessary
kernel modules (at least on a MIPS embedded device).
Using arc4 directly not only eliminates those dependencies, it also makes
the code smaller.
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/net/mac80211/wep.c b/net/mac80211/wep.c
index 2ff6d1e..a1c6bfd 100644
--- a/net/mac80211/wep.c
+++ b/net/mac80211/wep.c
@@ -30,17 +30,15 @@
/* start WEP IV from a random value */
get_random_bytes(&local->wep_iv, WEP_IV_LEN);
- local->wep_tx_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0,
- CRYPTO_ALG_ASYNC);
+ local->wep_tx_tfm = crypto_alloc_cipher("arc4", 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(local->wep_tx_tfm)) {
local->wep_rx_tfm = ERR_PTR(-EINVAL);
return PTR_ERR(local->wep_tx_tfm);
}
- local->wep_rx_tfm = crypto_alloc_blkcipher("ecb(arc4)", 0,
- CRYPTO_ALG_ASYNC);
+ local->wep_rx_tfm = crypto_alloc_cipher("arc4", 0, CRYPTO_ALG_ASYNC);
if (IS_ERR(local->wep_rx_tfm)) {
- crypto_free_blkcipher(local->wep_tx_tfm);
+ crypto_free_cipher(local->wep_tx_tfm);
local->wep_tx_tfm = ERR_PTR(-EINVAL);
return PTR_ERR(local->wep_rx_tfm);
}
@@ -51,9 +49,9 @@
void ieee80211_wep_free(struct ieee80211_local *local)
{
if (!IS_ERR(local->wep_tx_tfm))
- crypto_free_blkcipher(local->wep_tx_tfm);
+ crypto_free_cipher(local->wep_tx_tfm);
if (!IS_ERR(local->wep_rx_tfm))
- crypto_free_blkcipher(local->wep_rx_tfm);
+ crypto_free_cipher(local->wep_rx_tfm);
}
static inline bool ieee80211_wep_weak_iv(u32 iv, int keylen)
@@ -127,12 +125,11 @@
/* Perform WEP encryption using given key. data buffer must have tailroom
* for 4-byte ICV. data_len must not include this ICV. Note: this function
* does _not_ add IV. data = RC4(data | CRC32(data)) */
-int ieee80211_wep_encrypt_data(struct crypto_blkcipher *tfm, u8 *rc4key,
+int ieee80211_wep_encrypt_data(struct crypto_cipher *tfm, u8 *rc4key,
size_t klen, u8 *data, size_t data_len)
{
- struct blkcipher_desc desc = { .tfm = tfm };
- struct scatterlist sg;
__le32 icv;
+ int i;
if (IS_ERR(tfm))
return -1;
@@ -140,9 +137,9 @@
icv = cpu_to_le32(~crc32_le(~0, data, data_len));
put_unaligned(icv, (__le32 *)(data + data_len));
- crypto_blkcipher_setkey(tfm, rc4key, klen);
- sg_init_one(&sg, data, data_len + WEP_ICV_LEN);
- crypto_blkcipher_encrypt(&desc, &sg, &sg, sg.length);
+ crypto_cipher_setkey(tfm, rc4key, klen);
+ for (i = 0; i < data_len + WEP_ICV_LEN; i++)
+ crypto_cipher_encrypt_one(tfm, data + i, data + i);
return 0;
}
@@ -186,19 +183,18 @@
/* Perform WEP decryption using given key. data buffer includes encrypted
* payload, including 4-byte ICV, but _not_ IV. data_len must not include ICV.
* Return 0 on success and -1 on ICV mismatch. */
-int ieee80211_wep_decrypt_data(struct crypto_blkcipher *tfm, u8 *rc4key,
+int ieee80211_wep_decrypt_data(struct crypto_cipher *tfm, u8 *rc4key,
size_t klen, u8 *data, size_t data_len)
{
- struct blkcipher_desc desc = { .tfm = tfm };
- struct scatterlist sg;
__le32 crc;
+ int i;
if (IS_ERR(tfm))
return -1;
- crypto_blkcipher_setkey(tfm, rc4key, klen);
- sg_init_one(&sg, data, data_len + WEP_ICV_LEN);
- crypto_blkcipher_decrypt(&desc, &sg, &sg, sg.length);
+ crypto_cipher_setkey(tfm, rc4key, klen);
+ for (i = 0; i < data_len + WEP_ICV_LEN; i++)
+ crypto_cipher_decrypt_one(tfm, data + i, data + i);
crc = cpu_to_le32(~crc32_le(~0, data, data_len));
if (memcmp(&crc, data + data_len, WEP_ICV_LEN) != 0)