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staging: rtl8723bs: Use existing arc4 implementation
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Use functions provided by <crypto/arc4.h> instead of hand writing them.

The implementations are slightly different, but are equivalent. It has
been checked with a test program which compares the output of the 2 sets of
functions.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
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@tititiou36 @intel-lab-lkp
tititiou36 authored and intel-lab-lkp committed Apr 10, 2021
1 parent f962296 commit e0f0911
Showing 1 changed file with 21 additions and 80 deletions.
101 changes: 21 additions & 80 deletions drivers/staging/rtl8723bs/core/rtw_security.c
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Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,7 @@
******************************************************************************/
#define _RTW_SECURITY_C_

#include <crypto/arc4.h>
#include <linux/crc32poly.h>
#include <drv_types.h>
#include <rtw_debug.h>
Expand All @@ -31,66 +32,6 @@ const char *security_type_str(u8 value)

/* WEP related ===== */

struct arc4context {
u32 x;
u32 y;
u8 state[256];
};


static void arcfour_init(struct arc4context *parc4ctx, u8 *key, u32 key_len)
{
u32 t, u;
u32 keyindex;
u32 stateindex;
u8 *state;
u32 counter;

state = parc4ctx->state;
parc4ctx->x = 0;
parc4ctx->y = 0;
for (counter = 0; counter < 256; counter++)
state[counter] = (u8)counter;
keyindex = 0;
stateindex = 0;
for (counter = 0; counter < 256; counter++) {
t = state[counter];
stateindex = (stateindex + key[keyindex] + t) & 0xff;
u = state[stateindex];
state[stateindex] = (u8)t;
state[counter] = (u8)u;
if (++keyindex >= key_len)
keyindex = 0;
}
}

static u32 arcfour_byte(struct arc4context *parc4ctx)
{
u32 x;
u32 y;
u32 sx, sy;
u8 *state;

state = parc4ctx->state;
x = (parc4ctx->x + 1) & 0xff;
sx = state[x];
y = (sx + parc4ctx->y) & 0xff;
sy = state[y];
parc4ctx->x = x;
parc4ctx->y = y;
state[y] = (u8)sx;
state[x] = (u8)sy;
return state[(sx + sy) & 0xff];
}

static void arcfour_encrypt(struct arc4context *parc4ctx, u8 *dest, u8 *src, u32 len)
{
u32 i;

for (i = 0; i < len; i++)
dest[i] = src[i] ^ (unsigned char)arcfour_byte(parc4ctx);
}

static signed int bcrc32initialized;
static u32 crc32_table[256];

Expand Down Expand Up @@ -150,7 +91,7 @@ void rtw_wep_encrypt(struct adapter *padapter, u8 *pxmitframe)
{ /* exclude ICV */

unsigned char crc[4];
struct arc4context mycontext;
struct arc4_ctx mycontext;

signed int curfragnum, length;
u32 keylength;
Expand Down Expand Up @@ -184,16 +125,16 @@ void rtw_wep_encrypt(struct adapter *padapter, u8 *pxmitframe)

*((__le32 *)crc) = getcrc32(payload, length);

arcfour_init(&mycontext, wepkey, 3+keylength);
arcfour_encrypt(&mycontext, payload, payload, length);
arcfour_encrypt(&mycontext, payload+length, crc, 4);
arc4_setkey(&mycontext, wepkey, 3 + keylength);
arc4_crypt(&mycontext, payload, payload, length);
arc4_crypt(&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);
arc4_setkey(&mycontext, wepkey, 3 + keylength);
arc4_crypt(&mycontext, payload, payload, length);
arc4_crypt(&mycontext, payload + length, crc, 4);

pframe += pxmitpriv->frag_len;
pframe = (u8 *)round_up((SIZE_PTR)(pframe), 4);
Expand All @@ -206,7 +147,7 @@ void rtw_wep_decrypt(struct adapter *padapter, u8 *precvframe)
{
/* exclude ICV */
u8 crc[4];
struct arc4context mycontext;
struct arc4_ctx mycontext;
signed int length;
u32 keylength;
u8 *pframe, *payload, *iv, wepkey[16];
Expand All @@ -230,8 +171,8 @@ void rtw_wep_decrypt(struct adapter *padapter, u8 *precvframe)
payload = pframe+prxattrib->iv_len+prxattrib->hdrlen;

/* decrypt payload include icv */
arcfour_init(&mycontext, wepkey, 3+keylength);
arcfour_encrypt(&mycontext, payload, payload, length);
arc4_setkey(&mycontext, wepkey, 3 + keylength);
arc4_crypt(&mycontext, payload, payload, length);

/* calculate icv and compare the icv */
*((u32 *)crc) = le32_to_cpu(getcrc32(payload, length-4));
Expand Down Expand Up @@ -579,7 +520,7 @@ u32 rtw_tkip_encrypt(struct adapter *padapter, u8 *pxmitframe)
u8 ttkey[16];
u8 crc[4];
u8 hw_hdr_offset = 0;
struct arc4context mycontext;
struct arc4_ctx mycontext;
signed int curfragnum, length;

u8 *pframe, *payload, *iv, *prwskey;
Expand Down Expand Up @@ -621,16 +562,16 @@ u32 rtw_tkip_encrypt(struct adapter *padapter, u8 *pxmitframe)
length = pattrib->last_txcmdsz-pattrib->hdrlen-pattrib->iv_len-pattrib->icv_len;
*((__le32 *)crc) = getcrc32(payload, length);/* modified by Amy*/

arcfour_init(&mycontext, rc4key, 16);
arcfour_encrypt(&mycontext, payload, payload, length);
arcfour_encrypt(&mycontext, payload+length, crc, 4);
arc4_setkey(&mycontext, rc4key, 16);
arc4_crypt(&mycontext, payload, payload, length);
arc4_crypt(&mycontext, payload + length, crc, 4);

} else {
length = pxmitpriv->frag_len-pattrib->hdrlen-pattrib->iv_len-pattrib->icv_len;
*((__le32 *)crc) = getcrc32(payload, length);/* modified by Amy*/
arcfour_init(&mycontext, rc4key, 16);
arcfour_encrypt(&mycontext, payload, payload, length);
arcfour_encrypt(&mycontext, payload+length, crc, 4);
arc4_setkey(&mycontext, rc4key, 16);
arc4_crypt(&mycontext, payload, payload, length);
arc4_crypt(&mycontext, payload + length, crc, 4);

pframe += pxmitpriv->frag_len;
pframe = (u8 *)round_up((SIZE_PTR)(pframe), 4);
Expand All @@ -650,7 +591,7 @@ u32 rtw_tkip_decrypt(struct adapter *padapter, u8 *precvframe)
u8 rc4key[16];
u8 ttkey[16];
u8 crc[4];
struct arc4context mycontext;
struct arc4_ctx mycontext;
signed int length;

u8 *pframe, *payload, *iv, *prwskey;
Expand Down Expand Up @@ -721,8 +662,8 @@ u32 rtw_tkip_decrypt(struct adapter *padapter, u8 *precvframe)

/* 4 decrypt payload include icv */

arcfour_init(&mycontext, rc4key, 16);
arcfour_encrypt(&mycontext, payload, payload, length);
arc4_setkey(&mycontext, rc4key, 16);
arc4_crypt(&mycontext, payload, payload, length);

*((u32 *)crc) = le32_to_cpu(getcrc32(payload, length-4));

Expand Down

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