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path: root/net/ieee80211/ieee80211_crypt_wep.c
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Diffstat (limited to 'net/ieee80211/ieee80211_crypt_wep.c')
-rw-r--r--net/ieee80211/ieee80211_crypt_wep.c61
1 files changed, 43 insertions, 18 deletions
diff --git a/net/ieee80211/ieee80211_crypt_wep.c b/net/ieee80211/ieee80211_crypt_wep.c
index 073aebdf0f6..f8dca31be5d 100644
--- a/net/ieee80211/ieee80211_crypt_wep.c
+++ b/net/ieee80211/ieee80211_crypt_wep.c
@@ -75,22 +75,14 @@ static void prism2_wep_deinit(void *priv)
kfree(priv);
}
-/* Perform WEP encryption on given skb that has at least 4 bytes of headroom
- * for IV and 4 bytes of tailroom for ICV. Both IV and ICV will be transmitted,
- * so the payload length increases with 8 bytes.
- *
- * WEP frame payload: IV + TX key idx, RC4(data), ICV = RC4(CRC32(data))
- */
-static int prism2_wep_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
+/* Add WEP IV/key info to a frame that has at least 4 bytes of headroom */
+static int prism2_wep_build_iv(struct sk_buff *skb, int hdr_len, void *priv)
{
struct prism2_wep_data *wep = priv;
- u32 crc, klen, len;
- u8 key[WEP_KEY_LEN + 3];
- u8 *pos, *icv;
- struct scatterlist sg;
-
- if (skb_headroom(skb) < 4 || skb_tailroom(skb) < 4 ||
- skb->len < hdr_len)
+ u32 klen, len;
+ u8 *pos;
+
+ if (skb_headroom(skb) < 4 || skb->len < hdr_len)
return -1;
len = skb->len - hdr_len;
@@ -112,15 +104,47 @@ static int prism2_wep_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
}
/* Prepend 24-bit IV to RC4 key and TX frame */
- *pos++ = key[0] = (wep->iv >> 16) & 0xff;
- *pos++ = key[1] = (wep->iv >> 8) & 0xff;
- *pos++ = key[2] = wep->iv & 0xff;
+ *pos++ = (wep->iv >> 16) & 0xff;
+ *pos++ = (wep->iv >> 8) & 0xff;
+ *pos++ = wep->iv & 0xff;
*pos++ = wep->key_idx << 6;
+ return 0;
+}
+
+/* Perform WEP encryption on given skb that has at least 4 bytes of headroom
+ * for IV and 4 bytes of tailroom for ICV. Both IV and ICV will be transmitted,
+ * so the payload length increases with 8 bytes.
+ *
+ * WEP frame payload: IV + TX key idx, RC4(data), ICV = RC4(CRC32(data))
+ */
+static int prism2_wep_encrypt(struct sk_buff *skb, int hdr_len, void *priv)
+{
+ struct prism2_wep_data *wep = priv;
+ u32 crc, klen, len;
+ u8 *pos, *icv;
+ struct scatterlist sg;
+ u8 key[WEP_KEY_LEN + 3];
+
+ /* other checks are in prism2_wep_build_iv */
+ if (skb_tailroom(skb) < 4)
+ return -1;
+
+ /* add the IV to the frame */
+ if (prism2_wep_build_iv(skb, hdr_len, priv))
+ return -1;
+
+ /* Copy the IV into the first 3 bytes of the key */
+ memcpy(key, skb->data + hdr_len, 3);
+
/* Copy rest of the WEP key (the secret part) */
memcpy(key + 3, wep->key, wep->key_len);
+
+ len = skb->len - hdr_len - 4;
+ pos = skb->data + hdr_len + 4;
+ klen = 3 + wep->key_len;
- /* Append little-endian CRC32 and encrypt it to produce ICV */
+ /* Append little-endian CRC32 over only the data and encrypt it to produce ICV */
crc = ~crc32_le(~0, pos, len);
icv = skb_put(skb, 4);
icv[0] = crc;
@@ -231,6 +255,7 @@ static struct ieee80211_crypto_ops ieee80211_crypt_wep = {
.name = "WEP",
.init = prism2_wep_init,
.deinit = prism2_wep_deinit,
+ .build_iv = prism2_wep_build_iv,
.encrypt_mpdu = prism2_wep_encrypt,
.decrypt_mpdu = prism2_wep_decrypt,
.encrypt_msdu = NULL,