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-rw-r--r--net/mac80211/michael.c106
1 files changed, 39 insertions, 67 deletions
diff --git a/net/mac80211/michael.c b/net/mac80211/michael.c
index 0f844f7895f1..1fcdf38cf60c 100644
--- a/net/mac80211/michael.c
+++ b/net/mac80211/michael.c
@@ -6,85 +6,58 @@
6 * it under the terms of the GNU General Public License version 2 as 6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation. 7 * published by the Free Software Foundation.
8 */ 8 */
9
10#include <linux/types.h> 9#include <linux/types.h>
10#include <linux/bitops.h>
11#include <asm/unaligned.h>
11 12
12#include "michael.h" 13#include "michael.h"
13 14
14static inline u32 rotr(u32 val, int bits) 15static void michael_block(struct michael_mic_ctx *mctx, u32 val)
15{
16 return (val >> bits) | (val << (32 - bits));
17}
18
19
20static inline u32 rotl(u32 val, int bits)
21{
22 return (val << bits) | (val >> (32 - bits));
23}
24
25
26static inline u32 xswap(u32 val)
27{
28 return ((val & 0xff00ff00) >> 8) | ((val & 0x00ff00ff) << 8);
29}
30
31
32#define michael_block(l, r) \
33do { \
34 r ^= rotl(l, 17); \
35 l += r; \
36 r ^= xswap(l); \
37 l += r; \
38 r ^= rotl(l, 3); \
39 l += r; \
40 r ^= rotr(l, 2); \
41 l += r; \
42} while (0)
43
44
45static inline u32 michael_get32(u8 *data)
46{ 16{
47 return data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24); 17 mctx->l ^= val;
18 mctx->r ^= rol32(mctx->l, 17);
19 mctx->l += mctx->r;
20 mctx->r ^= ((mctx->l & 0xff00ff00) >> 8) |
21 ((mctx->l & 0x00ff00ff) << 8);
22 mctx->l += mctx->r;
23 mctx->r ^= rol32(mctx->l, 3);
24 mctx->l += mctx->r;
25 mctx->r ^= ror32(mctx->l, 2);
26 mctx->l += mctx->r;
48} 27}
49 28
50 29static void michael_mic_hdr(struct michael_mic_ctx *mctx,
51static inline void michael_put32(u32 val, u8 *data) 30 const u8 *key, const u8 *da, const u8 *sa, u8 priority)
52{ 31{
53 data[0] = val & 0xff; 32 mctx->l = get_unaligned_le32(key);
54 data[1] = (val >> 8) & 0xff; 33 mctx->r = get_unaligned_le32(key + 4);
55 data[2] = (val >> 16) & 0xff; 34
56 data[3] = (val >> 24) & 0xff; 35 /*
36 * A pseudo header (DA, SA, Priority, 0, 0, 0) is used in Michael MIC
37 * calculation, but it is _not_ transmitted
38 */
39 michael_block(mctx, get_unaligned_le32(da));
40 michael_block(mctx, get_unaligned_le16(&da[4]) |
41 (get_unaligned_le16(sa) << 16));
42 michael_block(mctx, get_unaligned_le32(&sa[2]));
43 michael_block(mctx, priority);
57} 44}
58 45
59 46void michael_mic(const u8 *key, const u8 *da, const u8 *sa, u8 priority,
60void michael_mic(u8 *key, u8 *da, u8 *sa, u8 priority, 47 const u8 *data, size_t data_len, u8 *mic)
61 u8 *data, size_t data_len, u8 *mic)
62{ 48{
63 u32 l, r, val; 49 u32 val;
64 size_t block, blocks, left; 50 size_t block, blocks, left;
51 struct michael_mic_ctx mctx;
65 52
66 l = michael_get32(key); 53 michael_mic_hdr(&mctx, key, da, sa, priority);
67 r = michael_get32(key + 4);
68
69 /* A pseudo header (DA, SA, Priority, 0, 0, 0) is used in Michael MIC
70 * calculation, but it is _not_ transmitted */
71 l ^= michael_get32(da);
72 michael_block(l, r);
73 l ^= da[4] | (da[5] << 8) | (sa[0] << 16) | (sa[1] << 24);
74 michael_block(l, r);
75 l ^= michael_get32(&sa[2]);
76 michael_block(l, r);
77 l ^= priority;
78 michael_block(l, r);
79 54
80 /* Real data */ 55 /* Real data */
81 blocks = data_len / 4; 56 blocks = data_len / 4;
82 left = data_len % 4; 57 left = data_len % 4;
83 58
84 for (block = 0; block < blocks; block++) { 59 for (block = 0; block < blocks; block++)
85 l ^= michael_get32(&data[block * 4]); 60 michael_block(&mctx, get_unaligned_le32(&data[block * 4]));
86 michael_block(l, r);
87 }
88 61
89 /* Partial block of 0..3 bytes and padding: 0x5a + 4..7 zeros to make 62 /* Partial block of 0..3 bytes and padding: 0x5a + 4..7 zeros to make
90 * total length a multiple of 4. */ 63 * total length a multiple of 4. */
@@ -94,11 +67,10 @@ void michael_mic(u8 *key, u8 *da, u8 *sa, u8 priority,
94 left--; 67 left--;
95 val |= data[blocks * 4 + left]; 68 val |= data[blocks * 4 + left];
96 } 69 }
97 l ^= val;
98 michael_block(l, r);
99 /* last block is zero, so l ^ 0 = l */
100 michael_block(l, r);
101 70
102 michael_put32(l, mic); 71 michael_block(&mctx, val);
103 michael_put32(r, mic + 4); 72 michael_block(&mctx, 0);
73
74 put_unaligned_le32(mctx.l, mic);
75 put_unaligned_le32(mctx.r, mic + 4);
104} 76}