[PATCH v3] staging:r8188eu: Use lib80211 to encrypt (WEP) tx frames

From: Ivan Safonov
Date: Sat Jun 30 2018 - 13:24:30 EST


Put data to skb, decrypt with lib80211_crypt_wep, and place back to tx buffer.

Signed-off-by: Ivan Safonov <insafonov@xxxxxxxxx>
---
v2:
- refactor error handling,
v3:
- fix commit message.

drivers/staging/rtl8188eu/core/rtw_security.c | 82 +++++++++++++++------------
1 file changed, 47 insertions(+), 35 deletions(-)

diff --git a/drivers/staging/rtl8188eu/core/rtw_security.c b/drivers/staging/rtl8188eu/core/rtw_security.c
index 5b8d7288a4e7..a01290467c64 100644
--- a/drivers/staging/rtl8188eu/core/rtw_security.c
+++ b/drivers/staging/rtl8188eu/core/rtw_security.c
@@ -131,60 +131,72 @@ static __le32 getcrc32(u8 *buf, int len)
Need to consider the fragment situation
*/
void rtw_wep_encrypt(struct adapter *padapter, u8 *pxmitframe)
-{ /* exclude ICV */
-
- unsigned char crc[4];
- struct arc4context mycontext;
-
+{
int curfragnum, length;
- u32 keylength;
-
- u8 *pframe, *payload, *iv; /* wepkey */
- u8 wepkey[16];
- u8 hw_hdr_offset = 0;
+ u8 *pframe;
+ u8 hw_hdr_offset = 0;
struct pkt_attrib *pattrib = &((struct xmit_frame *)pxmitframe)->attrib;
struct security_priv *psecuritypriv = &padapter->securitypriv;
struct xmit_priv *pxmitpriv = &padapter->xmitpriv;
-
+ const int keyindex = psecuritypriv->dot11PrivacyKeyIndex;
+ void *crypto_private;
+ struct sk_buff *skb;
+ struct lib80211_crypto_ops *crypto_ops;

if (((struct xmit_frame *)pxmitframe)->buf_addr == NULL)
return;

+ if ((pattrib->encrypt != _WEP40_) && (pattrib->encrypt != _WEP104_))
+ return;
+
hw_hdr_offset = TXDESC_SIZE +
(((struct xmit_frame *)pxmitframe)->pkt_offset * PACKET_OFFSET_SZ);

pframe = ((struct xmit_frame *)pxmitframe)->buf_addr + hw_hdr_offset;

- /* start to encrypt each fragment */
- if ((pattrib->encrypt == _WEP40_) || (pattrib->encrypt == _WEP104_)) {
- keylength = psecuritypriv->dot11DefKeylen[psecuritypriv->dot11PrivacyKeyIndex];
+ crypto_ops = try_then_request_module(lib80211_get_crypto_ops("WEP"), "lib80211_crypt_wep");

- for (curfragnum = 0; curfragnum < pattrib->nr_frags; curfragnum++) {
- iv = pframe+pattrib->hdrlen;
- memcpy(&wepkey[0], iv, 3);
- memcpy(&wepkey[3], &psecuritypriv->dot11DefKey[psecuritypriv->dot11PrivacyKeyIndex].skey[0], keylength);
- payload = pframe+pattrib->iv_len+pattrib->hdrlen;
+ if (!crypto_ops)
+ return;

- if ((curfragnum+1) == pattrib->nr_frags) { /* the last fragment */
- length = pattrib->last_txcmdsz-pattrib->hdrlen-pattrib->iv_len-pattrib->icv_len;
+ crypto_private = crypto_ops->init(keyindex);
+ if (!crypto_private)
+ return;

- *((__le32 *)crc) = getcrc32(payload, length);
+ if (crypto_ops->set_key(psecuritypriv->dot11DefKey[keyindex].skey,
+ psecuritypriv->dot11DefKeylen[keyindex], NULL, crypto_private) < 0)
+ goto free_crypto_private;

- arcfour_init(&mycontext, wepkey, 3+keylength);
- arcfour_encrypt(&mycontext, payload, payload, length);
- arcfour_encrypt(&mycontext, payload+length, crc, 4);
- } else {
- length = pxmitpriv->frag_len-pattrib->hdrlen-pattrib->iv_len-pattrib->icv_len;
- *((__le32 *)crc) = getcrc32(payload, length);
- arcfour_init(&mycontext, wepkey, 3+keylength);
- arcfour_encrypt(&mycontext, payload, payload, length);
- arcfour_encrypt(&mycontext, payload+length, crc, 4);
-
- pframe += pxmitpriv->frag_len;
- pframe = (u8 *)round_up((size_t)(pframe), 4);
- }
+ for (curfragnum = 0; curfragnum < pattrib->nr_frags; curfragnum++) {
+ if (curfragnum + 1 == pattrib->nr_frags)
+ length = pattrib->last_txcmdsz;
+ else
+ length = pxmitpriv->frag_len;
+ skb = dev_alloc_skb(length);
+ if (!skb)
+ goto free_crypto_private;
+
+ skb_put_data(skb, pframe, length);
+
+ memmove(skb->data + 4, skb->data, pattrib->hdrlen);
+ skb_pull(skb, 4);
+ skb_trim(skb, skb->len - 4);
+
+ if (crypto_ops->encrypt_mpdu(skb, pattrib->hdrlen, crypto_private)) {
+ kfree_skb(skb);
+ goto free_crypto_private;
}
+
+ memcpy(pframe, skb->data, skb->len);
+
+ pframe += skb->len;
+ pframe = (u8 *)round_up((size_t)(pframe), 4);
+
+ kfree_skb(skb);
}
+
+free_crypto_private:
+ crypto_ops->deinit(crypto_private);
}

int rtw_wep_decrypt(struct adapter *padapter, u8 *precvframe)
--
2.16.4