[PATCH 3/3] staging: rtl8712: Use existing arc4 implementation
From: Christophe JAILLET
Date: Sat Apr 10 2021 - 07:57:02 EST
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@xxxxxxxxxx>
---
drivers/staging/rtl8712/rtl871x_security.c | 118 +++++----------------
1 file changed, 29 insertions(+), 89 deletions(-)
diff --git a/drivers/staging/rtl8712/rtl871x_security.c b/drivers/staging/rtl8712/rtl871x_security.c
index 1c7df65db3c9..b546e2f19620 100644
--- a/drivers/staging/rtl8712/rtl871x_security.c
+++ b/drivers/staging/rtl8712/rtl871x_security.c
@@ -16,6 +16,7 @@
#define _RTL871X_SECURITY_C_
+#include <crypto/arc4.h>
#include <linux/compiler.h>
#include <linux/kernel.h>
#include <linux/errno.h>
@@ -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];
@@ -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];
@@ -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));
}
@@ -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;
@@ -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));
}
@@ -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;
@@ -606,11 +547,11 @@ 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 -
@@ -618,12 +559,11 @@ 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);
pframe += pxmitpriv->frag_len;
pframe = (u8 *)RND4((addr_t)(pframe));
}
@@ -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;
@@ -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));
}
--
2.27.0