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staging:r8188eu: use lib80211 CCMP decrypt
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Custom AES decrypt implementation replaced with lib80211 library.

Signed-off-by: Ivan Safonov <insafonov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Ivan Safonov authored and Greg Kroah-Hartman committed Mar 1, 2018
1 parent a3d2ae0 commit 6bd082a
Showing 2 changed files with 51 additions and 216 deletions.
1 change: 1 addition & 0 deletions drivers/staging/rtl8188eu/Kconfig
View file
Original file line number Diff line number Diff line change
@@ -6,6 +6,7 @@ config R8188EU
select WEXT_PRIV
select LIB80211
select LIB80211_CRYPT_WEP
select LIB80211_CRYPT_CCMP
---help---
This option adds the Realtek RTL8188EU USB device such as TP-Link TL-WN725N.
If built as a module, it will be called r8188eu.
266 changes: 50 additions & 216 deletions drivers/staging/rtl8188eu/core/rtw_security.c
View file
Original file line number Diff line number Diff line change
@@ -1275,217 +1275,24 @@ u32 rtw_aes_encrypt(struct adapter *padapter, u8 *pxmitframe)
return res;
}

static int aes_decipher(u8 *key, uint hdrlen,
u8 *pframe, uint plen)
u32 rtw_aes_decrypt(struct adapter *padapter, u8 *precvframe)
{
static u8 message[MAX_MSG_SIZE];
uint qc_exists, a4_exists, i, j, payload_remainder,
num_blocks, payload_index;
int res = _SUCCESS;

u8 pn_vector[6];
u8 mic_iv[16];
u8 mic_header1[16];
u8 mic_header2[16];
u8 ctr_preload[16];

/* Intermediate Buffers */
u8 chain_buffer[16];
u8 aes_out[16];
u8 padded_buffer[16];
u8 mic[8];

/* uint offset = 0; */
uint frtype = GetFrameType(pframe);
uint frsubtype = GetFrameSubType(pframe);
frsubtype >>= 4;

memset(mic_iv, 0, 16);
memset(mic_header1, 0, 16);
memset(mic_header2, 0, 16);
memset(ctr_preload, 0, 16);
memset(chain_buffer, 0, 16);
memset(aes_out, 0, 16);
memset(padded_buffer, 0, 16);

/* start to decrypt the payload */

num_blocks = (plen-8) / 16; /* plen including llc, payload_length and mic) */

payload_remainder = (plen-8) % 16;

pn_vector[0] = pframe[hdrlen];
pn_vector[1] = pframe[hdrlen+1];
pn_vector[2] = pframe[hdrlen+4];
pn_vector[3] = pframe[hdrlen+5];
pn_vector[4] = pframe[hdrlen+6];
pn_vector[5] = pframe[hdrlen+7];

if ((hdrlen == WLAN_HDR_A3_LEN) || (hdrlen == WLAN_HDR_A3_QOS_LEN))
a4_exists = 0;
else
a4_exists = 1;

if ((frtype == WIFI_DATA_CFACK) || (frtype == WIFI_DATA_CFPOLL) ||
(frtype == WIFI_DATA_CFACKPOLL)) {
qc_exists = 1;
if (hdrlen != WLAN_HDR_A3_QOS_LEN)
hdrlen += 2;
} else if ((frsubtype == 0x08) || (frsubtype == 0x09) ||
(frsubtype == 0x0a) || (frsubtype == 0x0b)) {
if (hdrlen != WLAN_HDR_A3_QOS_LEN)
hdrlen += 2;
qc_exists = 1;
} else {
qc_exists = 0;
}

/* now, decrypt pframe with hdrlen offset and plen long */

payload_index = hdrlen + 8; /* 8 is for extiv */

for (i = 0; i < num_blocks; i++) {
construct_ctr_preload(ctr_preload, a4_exists, qc_exists, pframe, pn_vector, i+1);

aes128k128d(key, ctr_preload, aes_out);
bitwise_xor(aes_out, &pframe[payload_index], chain_buffer);

for (j = 0; j < 16; j++)
pframe[payload_index++] = chain_buffer[j];
}

if (payload_remainder > 0) { /* If there is a short final block, then pad it,*/
/* encrypt it and copy the unpadded part back */
construct_ctr_preload(ctr_preload, a4_exists, qc_exists, pframe, pn_vector, num_blocks+1);

for (j = 0; j < 16; j++)
padded_buffer[j] = 0x00;
for (j = 0; j < payload_remainder; j++)
padded_buffer[j] = pframe[payload_index+j];
aes128k128d(key, ctr_preload, aes_out);
bitwise_xor(aes_out, padded_buffer, chain_buffer);
for (j = 0; j < payload_remainder; j++)
pframe[payload_index++] = chain_buffer[j];
}

/* start to calculate the mic */
if ((hdrlen+plen+8) <= MAX_MSG_SIZE)
memcpy(message, pframe, (hdrlen + plen+8)); /* 8 is for ext iv len */

pn_vector[0] = pframe[hdrlen];
pn_vector[1] = pframe[hdrlen+1];
pn_vector[2] = pframe[hdrlen+4];
pn_vector[3] = pframe[hdrlen+5];
pn_vector[4] = pframe[hdrlen+6];
pn_vector[5] = pframe[hdrlen+7];
construct_mic_iv(mic_iv, qc_exists, a4_exists, message, plen-8, pn_vector);

construct_mic_header1(mic_header1, hdrlen, message);
construct_mic_header2(mic_header2, message, a4_exists, qc_exists);

payload_remainder = (plen-8) % 16;
num_blocks = (plen-8) / 16;

/* Find start of payload */
payload_index = hdrlen + 8;

/* Calculate MIC */
aes128k128d(key, mic_iv, aes_out);
bitwise_xor(aes_out, mic_header1, chain_buffer);
aes128k128d(key, chain_buffer, aes_out);
bitwise_xor(aes_out, mic_header2, chain_buffer);
aes128k128d(key, chain_buffer, aes_out);

for (i = 0; i < num_blocks; i++) {
bitwise_xor(aes_out, &message[payload_index], chain_buffer);

payload_index += 16;
aes128k128d(key, chain_buffer, aes_out);
}

/* Add on the final payload block if it needs padding */
if (payload_remainder > 0) {
for (j = 0; j < 16; j++)
padded_buffer[j] = 0x00;
for (j = 0; j < payload_remainder; j++)
padded_buffer[j] = message[payload_index++];
bitwise_xor(aes_out, padded_buffer, chain_buffer);
aes128k128d(key, chain_buffer, aes_out);
}

for (j = 0 ; j < 8; j++)
mic[j] = aes_out[j];

/* Insert MIC into payload */
for (j = 0; j < 8; j++)
message[payload_index+j] = mic[j];

payload_index = hdrlen + 8;
for (i = 0; i < num_blocks; i++) {
construct_ctr_preload(ctr_preload, a4_exists, qc_exists, message, pn_vector, i+1);
aes128k128d(key, ctr_preload, aes_out);
bitwise_xor(aes_out, &message[payload_index], chain_buffer);
for (j = 0; j < 16; j++)
message[payload_index++] = chain_buffer[j];
}

if (payload_remainder > 0) { /* If there is a short final block, then pad it,*/
/* encrypt it and copy the unpadded part back */
construct_ctr_preload(ctr_preload, a4_exists, qc_exists, message, pn_vector, num_blocks+1);

for (j = 0; j < 16; j++)
padded_buffer[j] = 0x00;
for (j = 0; j < payload_remainder; j++)
padded_buffer[j] = message[payload_index+j];
aes128k128d(key, ctr_preload, aes_out);
bitwise_xor(aes_out, padded_buffer, chain_buffer);
for (j = 0; j < payload_remainder; j++)
message[payload_index++] = chain_buffer[j];
}

/* Encrypt the MIC */
construct_ctr_preload(ctr_preload, a4_exists, qc_exists, message, pn_vector, 0);

for (j = 0; j < 16; j++)
padded_buffer[j] = 0x00;
for (j = 0; j < 8; j++)
padded_buffer[j] = message[j+hdrlen+8+plen-8];

aes128k128d(key, ctr_preload, aes_out);
bitwise_xor(aes_out, padded_buffer, chain_buffer);
for (j = 0; j < 8; j++)
message[payload_index++] = chain_buffer[j];

/* compare the mic */
for (i = 0; i < 8; i++) {
if (pframe[hdrlen+8+plen-8+i] != message[hdrlen+8+plen-8+i]) {
RT_TRACE(_module_rtl871x_security_c_, _drv_err_,
("aes_decipher:mic check error mic[%d]: pframe(%x)!=message(%x)\n",
i, pframe[hdrlen+8+plen-8+i], message[hdrlen+8+plen-8+i]));
DBG_88E("aes_decipher:mic check error mic[%d]: pframe(%x)!=message(%x)\n",
i, pframe[hdrlen+8+plen-8+i], message[hdrlen+8+plen-8+i]);
res = _FAIL;
}
}
return res;
}

u32 rtw_aes_decrypt(struct adapter *padapter, u8 *precvframe)
{ /* exclude ICV */
/* Intermediate Buffers */
int length;
u8 *pframe, *prwskey; /* *payload,*iv */
struct sta_info *stainfo;
struct rx_pkt_attrib *prxattrib = &((struct recv_frame *)precvframe)->attrib;
struct security_priv *psecuritypriv = &padapter->securitypriv;
u32 res = _SUCCESS;
struct rx_pkt_attrib *prxattrib = &((struct recv_frame *)precvframe)->attrib;
u32 res = _SUCCESS;

pframe = (unsigned char *)((struct recv_frame *)precvframe)->pkt->data;
/* 4 start to encrypt each fragment */
if (prxattrib->encrypt == _AES_) {
stainfo = rtw_get_stainfo(&padapter->stapriv, &prxattrib->ta[0]);
struct sta_info *stainfo = rtw_get_stainfo(&padapter->stapriv, &prxattrib->ta[0]);

if (stainfo != NULL) {
RT_TRACE(_module_rtl871x_security_c_, _drv_err_, ("rtw_aes_decrypt: stainfo!= NULL!!!\n"));
int key_idx;
const int key_length = 16, iv_len = 8, icv_len = 8;
struct sk_buff *skb = ((struct recv_frame *)precvframe)->pkt;
void *crypto_private = NULL;
u8 *key, *pframe = skb->data;
struct lib80211_crypto_ops *crypto_ops = try_then_request_module(lib80211_get_crypto_ops("CCMP"), "lib80211_crypt_ccmp");
struct security_priv *psecuritypriv = &padapter->securitypriv;
char iv[8], icv[8];

if (IS_MCAST(prxattrib->ra)) {
/* in concurrent we should use sw descrypt in group key, so we remove this message */
@@ -1494,18 +1301,45 @@ u32 rtw_aes_decrypt(struct adapter *padapter, u8 *precvframe)
DBG_88E("%s:rx bc/mc packets, but didn't install group key!!!!!!!!!!\n", __func__);
goto exit;
}
prwskey = psecuritypriv->dot118021XGrpKey[prxattrib->key_index].skey;
if (psecuritypriv->dot118021XGrpKeyid != prxattrib->key_index) {
DBG_88E("not match packet_index=%d, install_index=%d\n",
prxattrib->key_index, psecuritypriv->dot118021XGrpKeyid);
res = _FAIL;
goto exit;
}
key_idx = psecuritypriv->dot118021XGrpKeyid;
key = psecuritypriv->dot118021XGrpKey[key_idx].skey;
} else {
prwskey = &stainfo->dot118021x_UncstKey.skey[0];
key_idx = 0;
key = stainfo->dot118021x_UncstKey.skey;
}
length = ((struct recv_frame *)precvframe)->pkt->len-prxattrib->hdrlen-prxattrib->iv_len;
res = aes_decipher(prwskey, prxattrib->hdrlen, pframe, length);

if (!crypto_ops) {
res = _FAIL;
goto exit_lib80211_ccmp;
}

memcpy(iv, pframe + prxattrib->hdrlen, iv_len);
memcpy(icv, pframe + skb->len - icv_len, icv_len);

crypto_private = crypto_ops->init(key_idx);
if (!crypto_private) {
res = _FAIL;
goto exit_lib80211_ccmp;
}
if (crypto_ops->set_key(key, key_length, NULL, crypto_private) < 0) {
res = _FAIL;
goto exit_lib80211_ccmp;
}
if (crypto_ops->decrypt_mpdu(skb, prxattrib->hdrlen, crypto_private)) {
res = _FAIL;
goto exit_lib80211_ccmp;
}

memmove(pframe, pframe + iv_len, prxattrib->hdrlen);
skb_push(skb, iv_len);
skb_put(skb, icv_len);

memcpy(pframe + prxattrib->hdrlen, iv, iv_len);
memcpy(pframe + skb->len - icv_len, icv, icv_len);

exit_lib80211_ccmp:
if (crypto_ops && crypto_private)
crypto_ops->deinit(crypto_private);
} else {
RT_TRACE(_module_rtl871x_security_c_, _drv_err_, ("rtw_aes_encrypt: stainfo==NULL!!!\n"));
res = _FAIL;

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