diff options
author | Jiri Benc <jbenc@suse.cz> | 2007-05-05 14:45:53 -0400 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2007-05-05 14:45:53 -0400 |
commit | f0706e828e96d0fa4e80c0d25aa98523f6d589a0 (patch) | |
tree | a03c7f94939d74c1e1b82fcd9a215871590d8b35 /net/mac80211/michael.c | |
parent | a9de8ce0943e03b425be18561f51159fcceb873d (diff) |
[MAC80211]: Add mac80211 wireless stack.
Add mac80211, the IEEE 802.11 software MAC layer.
Signed-off-by: Jiri Benc <jbenc@suse.cz>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net/mac80211/michael.c')
-rw-r--r-- | net/mac80211/michael.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/net/mac80211/michael.c b/net/mac80211/michael.c new file mode 100644 index 000000000000..0f844f7895f1 --- /dev/null +++ b/net/mac80211/michael.c | |||
@@ -0,0 +1,104 @@ | |||
1 | /* | ||
2 | * Michael MIC implementation - optimized for TKIP MIC operations | ||
3 | * Copyright 2002-2003, Instant802 Networks, Inc. | ||
4 | * | ||
5 | * This program is free software; you can redistribute it and/or modify | ||
6 | * it under the terms of the GNU General Public License version 2 as | ||
7 | * published by the Free Software Foundation. | ||
8 | */ | ||
9 | |||
10 | #include <linux/types.h> | ||
11 | |||
12 | #include "michael.h" | ||
13 | |||
14 | static inline u32 rotr(u32 val, int bits) | ||
15 | { | ||
16 | return (val >> bits) | (val << (32 - bits)); | ||
17 | } | ||
18 | |||
19 | |||
20 | static inline u32 rotl(u32 val, int bits) | ||
21 | { | ||
22 | return (val << bits) | (val >> (32 - bits)); | ||
23 | } | ||
24 | |||
25 | |||
26 | static inline u32 xswap(u32 val) | ||
27 | { | ||
28 | return ((val & 0xff00ff00) >> 8) | ((val & 0x00ff00ff) << 8); | ||
29 | } | ||
30 | |||
31 | |||
32 | #define michael_block(l, r) \ | ||
33 | do { \ | ||
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 | |||
45 | static inline u32 michael_get32(u8 *data) | ||
46 | { | ||
47 | return data[0] | (data[1] << 8) | (data[2] << 16) | (data[3] << 24); | ||
48 | } | ||
49 | |||
50 | |||
51 | static inline void michael_put32(u32 val, u8 *data) | ||
52 | { | ||
53 | data[0] = val & 0xff; | ||
54 | data[1] = (val >> 8) & 0xff; | ||
55 | data[2] = (val >> 16) & 0xff; | ||
56 | data[3] = (val >> 24) & 0xff; | ||
57 | } | ||
58 | |||
59 | |||
60 | void michael_mic(u8 *key, u8 *da, u8 *sa, u8 priority, | ||
61 | u8 *data, size_t data_len, u8 *mic) | ||
62 | { | ||
63 | u32 l, r, val; | ||
64 | size_t block, blocks, left; | ||
65 | |||
66 | l = michael_get32(key); | ||
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 | |||
80 | /* Real data */ | ||
81 | blocks = data_len / 4; | ||
82 | left = data_len % 4; | ||
83 | |||
84 | for (block = 0; block < blocks; block++) { | ||
85 | l ^= michael_get32(&data[block * 4]); | ||
86 | michael_block(l, r); | ||
87 | } | ||
88 | |||
89 | /* Partial block of 0..3 bytes and padding: 0x5a + 4..7 zeros to make | ||
90 | * total length a multiple of 4. */ | ||
91 | val = 0x5a; | ||
92 | while (left > 0) { | ||
93 | val <<= 8; | ||
94 | left--; | ||
95 | val |= data[blocks * 4 + left]; | ||
96 | } | ||
97 | l ^= val; | ||
98 | michael_block(l, r); | ||
99 | /* last block is zero, so l ^ 0 = l */ | ||
100 | michael_block(l, r); | ||
101 | |||
102 | michael_put32(l, mic); | ||
103 | michael_put32(r, mic + 4); | ||
104 | } | ||