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-rw-r--r--net/mac80211/michael.c116
1 files changed, 49 insertions, 67 deletions
diff --git a/net/mac80211/michael.c b/net/mac80211/michael.c
index 0f844f7895f1..408649bd4702 100644
--- a/net/mac80211/michael.c
+++ b/net/mac80211/michael.c
@@ -6,85 +6,68 @@
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 <linux/ieee80211.h>
12#include <asm/unaligned.h>
11 13
12#include "michael.h" 14#include "michael.h"
13 15
14static inline u32 rotr(u32 val, int bits) 16static 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{ 17{
47 return data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24); 18 mctx->l ^= val;
19 mctx->r ^= rol32(mctx->l, 17);
20 mctx->l += mctx->r;
21 mctx->r ^= ((mctx->l & 0xff00ff00) >> 8) |
22 ((mctx->l & 0x00ff00ff) << 8);
23 mctx->l += mctx->r;
24 mctx->r ^= rol32(mctx->l, 3);
25 mctx->l += mctx->r;
26 mctx->r ^= ror32(mctx->l, 2);
27 mctx->l += mctx->r;
48} 28}
49 29
50 30static void michael_mic_hdr(struct michael_mic_ctx *mctx, const u8 *key,
51static inline void michael_put32(u32 val, u8 *data) 31 struct ieee80211_hdr *hdr)
52{ 32{
53 data[0] = val & 0xff; 33 u8 *da, *sa, tid;
54 data[1] = (val >> 8) & 0xff; 34
55 data[2] = (val >> 16) & 0xff; 35 da = ieee80211_get_DA(hdr);
56 data[3] = (val >> 24) & 0xff; 36 sa = ieee80211_get_SA(hdr);
37 if (ieee80211_is_data_qos(hdr->frame_control))
38 tid = *ieee80211_get_qos_ctl(hdr) & IEEE80211_QOS_CTL_TID_MASK;
39 else
40 tid = 0;
41
42 mctx->l = get_unaligned_le32(key);
43 mctx->r = get_unaligned_le32(key + 4);
44
45 /*
46 * A pseudo header (DA, SA, Priority, 0, 0, 0) is used in Michael MIC
47 * calculation, but it is _not_ transmitted
48 */
49 michael_block(mctx, get_unaligned_le32(da));
50 michael_block(mctx, get_unaligned_le16(&da[4]) |
51 (get_unaligned_le16(sa) << 16));
52 michael_block(mctx, get_unaligned_le32(&sa[2]));
53 michael_block(mctx, tid);
57} 54}
58 55
59 56void michael_mic(const u8 *key, struct ieee80211_hdr *hdr,
60void michael_mic(u8 *key, u8 *da, u8 *sa, u8 priority, 57 const u8 *data, size_t data_len, u8 *mic)
61 u8 *data, size_t data_len, u8 *mic)
62{ 58{
63 u32 l, r, val; 59 u32 val;
64 size_t block, blocks, left; 60 size_t block, blocks, left;
61 struct michael_mic_ctx mctx;
65 62
66 l = michael_get32(key); 63 michael_mic_hdr(&mctx, key, hdr);
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 64
80 /* Real data */ 65 /* Real data */
81 blocks = data_len / 4; 66 blocks = data_len / 4;
82 left = data_len % 4; 67 left = data_len % 4;
83 68
84 for (block = 0; block < blocks; block++) { 69 for (block = 0; block < blocks; block++)
85 l ^= michael_get32(&data[block * 4]); 70 michael_block(&mctx, get_unaligned_le32(&data[block * 4]));
86 michael_block(l, r);
87 }
88 71
89 /* Partial block of 0..3 bytes and padding: 0x5a + 4..7 zeros to make 72 /* Partial block of 0..3 bytes and padding: 0x5a + 4..7 zeros to make
90 * total length a multiple of 4. */ 73 * total length a multiple of 4. */
@@ -94,11 +77,10 @@ void michael_mic(u8 *key, u8 *da, u8 *sa, u8 priority,
94 left--; 77 left--;
95 val |= data[blocks * 4 + left]; 78 val |= data[blocks * 4 + left];
96 } 79 }
97 l ^= val;
98 michael_block(l, r);
99 /* last block is zero, so l ^ 0 = l */
100 michael_block(l, r);
101 80
102 michael_put32(l, mic); 81 michael_block(&mctx, val);
103 michael_put32(r, mic + 4); 82 michael_block(&mctx, 0);
83
84 put_unaligned_le32(mctx.l, mic);
85 put_unaligned_le32(mctx.r, mic + 4);
104} 86}