2 * Michael MIC implementation - optimized for TKIP MIC operations
3 * Copyright 2002-2003, Instant802 Networks, Inc.
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.
10 #include <linux/types.h>
14 static inline u32
rotr(u32 val
, int bits
)
16 return (val
>> bits
) | (val
<< (32 - bits
));
20 static inline u32
rotl(u32 val
, int bits
)
22 return (val
<< bits
) | (val
>> (32 - bits
));
26 static inline u32
xswap(u32 val
)
28 return ((val
& 0xff00ff00) >> 8) | ((val
& 0x00ff00ff) << 8);
32 #define michael_block(l, r) \
45 static inline u32
michael_get32(u8
*data
)
47 return data
[0] | (data
[1] << 8) | (data
[2] << 16) | (data
[3] << 24);
51 static inline void michael_put32(u32 val
, u8
*data
)
54 data
[1] = (val
>> 8) & 0xff;
55 data
[2] = (val
>> 16) & 0xff;
56 data
[3] = (val
>> 24) & 0xff;
60 void michael_mic(u8
*key
, u8
*da
, u8
*sa
, u8 priority
,
61 u8
*data
, size_t data_len
, u8
*mic
)
64 size_t block
, blocks
, left
;
66 l
= michael_get32(key
);
67 r
= michael_get32(key
+ 4);
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
);
73 l
^= da
[4] | (da
[5] << 8) | (sa
[0] << 16) | (sa
[1] << 24);
75 l
^= michael_get32(&sa
[2]);
81 blocks
= data_len
/ 4;
84 for (block
= 0; block
< blocks
; block
++) {
85 l
^= michael_get32(&data
[block
* 4]);
89 /* Partial block of 0..3 bytes and padding: 0x5a + 4..7 zeros to make
90 * total length a multiple of 4. */
95 val
|= data
[blocks
* 4 + left
];
99 /* last block is zero, so l ^ 0 = l */
102 michael_put32(l
, mic
);
103 michael_put32(r
, mic
+ 4);
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