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From:   Ivan Safonov <insafonov@gmail.com>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Dan Carpenter <dan.carpenter@oracle.com>,
        devel@driverdev.osuosl.org,
        Santha Meena Ramamoorthy <santhameena13@gmail.com>,
        Janani Sankara Babu <jananis37@gmail.com>,
        linux-kernel@vger.kernel.org, Ivan Safonov <insafonov@gmail.com>
Subject: [PATCH v2] staging:r8188eu: Use lib80211 to encrypt (WEP) tx frames
Date:   Sat, 30 Jun 2018 18:01:23 +0300
Message-Id: <20180630150123.32539-1-insafonov@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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

---
v2:
  - refactor error handling.

Signed-off-by: Ivan Safonov <insafonov@gmail.com>
---
 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