Skip to content

Commit

Permalink
staging: rtl8712: Use existing arc4 implementation
Browse files Browse the repository at this point in the history 
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>
  • Loading branch information
@tititiou36 @intel-lab-lkp
tititiou36 authored and intel-lab-lkp committed Apr 10, 2021
1 parent e0f0911 commit ea2709e
Showing 1 changed file with 29 additions and 89 deletions.
118 changes: 29 additions & 89 deletions drivers/staging/rtl8712/rtl871x_security.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,7 @@

#define _RTL871X_SECURITY_C_

#include <crypto/arc4.h>
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/errno.h>
Expand All @@ -38,66 +39,6 @@

/* =====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 sint bcrc32initialized;
static u32 crc32_table[256];

Expand Down Expand Up @@ -151,7 +92,7 @@ static u32 getcrc32(u8 *buf, u32 len)
void r8712_wep_encrypt(struct _adapter *padapter, u8 *pxmitframe)
{ /* exclude ICV */
unsigned char crc[4];
struct arc4context mycontext;
struct arc4_ctx mycontext;
u32 curfragnum, length, keylength, pki;
u8 *pframe, *payload, *iv; /*,*wepkey*/
u8 wepkey[16];
Expand Down Expand Up @@ -182,22 +123,22 @@ void r8712_wep_encrypt(struct _adapter *padapter, u8 *pxmitframe)
pattrib->icv_len;
*((__le32 *)crc) = cpu_to_le32(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) = cpu_to_le32(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 *)RND4((addr_t)(pframe));
}
Expand All @@ -209,7 +150,7 @@ void r8712_wep_decrypt(struct _adapter *padapter, u8 *precvframe)
{
/* exclude ICV */
u8 crc[4];
struct arc4context mycontext;
struct arc4_ctx mycontext;
u32 length, keylength;
u8 *pframe, *payload, *iv, wepkey[16];
u8 keyindex;
Expand All @@ -233,8 +174,8 @@ void r8712_wep_decrypt(struct _adapter *padapter, u8 *precvframe)
u.hdr.len - prxattrib->hdrlen - prxattrib->iv_len;
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 */
*((__le32 *)crc) = cpu_to_le32(getcrc32(payload, length - 4));
}
Expand Down Expand Up @@ -563,7 +504,7 @@ u32 r8712_tkip_encrypt(struct _adapter *padapter, u8 *pxmitframe)
u8 rc4key[16];
u8 ttkey[16];
u8 crc[4];
struct arc4context mycontext;
struct arc4_ctx mycontext;
u32 curfragnum, length;

u8 *pframe, *payload, *iv, *prwskey;
Expand Down Expand Up @@ -606,24 +547,23 @@ u32 r8712_tkip_encrypt(struct _adapter *padapter, u8 *pxmitframe)
pattrib->icv_len;
*((__le32 *)crc) = cpu_to_le32(
getcrc32(payload, length));
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) = cpu_to_le32(getcrc32(
payload, length));
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 *)RND4((addr_t)(pframe));
}
Expand All @@ -643,7 +583,7 @@ void r8712_tkip_decrypt(struct _adapter *padapter, u8 *precvframe)
u8 rc4key[16];
u8 ttkey[16];
u8 crc[4];
struct arc4context mycontext;
struct arc4_ctx mycontext;
u32 length;
u8 *pframe, *payload, *iv, *prwskey, idx = 0;
union pn48 txpn;
Expand Down Expand Up @@ -682,8 +622,8 @@ void r8712_tkip_decrypt(struct _adapter *padapter, u8 *precvframe)
phase2(&rc4key[0], prwskey, (unsigned short *)
&ttkey[0], pnl);
/* 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);
*((__le32 *)crc) = cpu_to_le32(getcrc32(payload,
length - 4));
}
Expand Down

0 comments on commit ea2709e

Please sign in to comment.