4 * Michael MIC (IEEE 802.11i/TKIP) keyed digest
6 * Copyright (c) 2004 Jouni Malinen <jkmaline@cc.hut.fi>
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/string.h>
16 //#include <linux/crypto.h>
17 #include "rtl_crypto.h"
20 struct michael_mic_ctx
{
28 static inline u32
rotl(u32 val
, int bits
)
30 return (val
<< bits
) | (val
>> (32 - bits
));
34 static inline u32
rotr(u32 val
, int bits
)
36 return (val
>> bits
) | (val
<< (32 - bits
));
40 static inline u32
xswap(u32 val
)
42 return ((val
& 0x00ff00ff) << 8) | ((val
& 0xff00ff00) >> 8);
46 #define michael_block(l, r) \
59 static inline u32
get_le32(const u8
*p
)
61 return p
[0] | (p
[1] << 8) | (p
[2] << 16) | (p
[3] << 24);
65 static inline void put_le32(u8
*p
, u32 v
)
74 static void michael_init(void *ctx
)
76 struct michael_mic_ctx
*mctx
= ctx
;
77 mctx
->pending_len
= 0;
81 static void michael_update(void *ctx
, const u8
*data
, unsigned int len
)
83 struct michael_mic_ctx
*mctx
= ctx
;
85 if (mctx
->pending_len
) {
86 int flen
= 4 - mctx
->pending_len
;
89 memcpy(&mctx
->pending
[mctx
->pending_len
], data
, flen
);
90 mctx
->pending_len
+= flen
;
94 if (mctx
->pending_len
< 4)
97 mctx
->l
^= get_le32(mctx
->pending
);
98 michael_block(mctx
->l
, mctx
->r
);
99 mctx
->pending_len
= 0;
103 mctx
->l
^= get_le32(data
);
104 michael_block(mctx
->l
, mctx
->r
);
110 mctx
->pending_len
= len
;
111 memcpy(mctx
->pending
, data
, len
);
116 static void michael_final(void *ctx
, u8
*out
)
118 struct michael_mic_ctx
*mctx
= ctx
;
119 u8
*data
= mctx
->pending
;
121 /* Last block and padding (0x5a, 4..7 x 0) */
122 switch (mctx
->pending_len
) {
127 mctx
->l
^= data
[0] | 0x5a00;
130 mctx
->l
^= data
[0] | (data
[1] << 8) | 0x5a0000;
133 mctx
->l
^= data
[0] | (data
[1] << 8) | (data
[2] << 16) |
137 michael_block(mctx
->l
, mctx
->r
);
139 michael_block(mctx
->l
, mctx
->r
);
141 put_le32(out
, mctx
->l
);
142 put_le32(out
+ 4, mctx
->r
);
146 static int michael_setkey(void *ctx
, const u8
*key
, unsigned int keylen
,
149 struct michael_mic_ctx
*mctx
= ctx
;
152 *flags
= CRYPTO_TFM_RES_BAD_KEY_LEN
;
155 mctx
->l
= get_le32(key
);
156 mctx
->r
= get_le32(key
+ 4);
161 static struct crypto_alg michael_mic_alg
= {
162 .cra_name
= "michael_mic",
163 .cra_flags
= CRYPTO_ALG_TYPE_DIGEST
,
165 .cra_ctxsize
= sizeof(struct michael_mic_ctx
),
166 .cra_module
= THIS_MODULE
,
167 .cra_list
= LIST_HEAD_INIT(michael_mic_alg
.cra_list
),
168 .cra_u
= { .digest
= {
170 .dia_init
= michael_init
,
171 .dia_update
= michael_update
,
172 .dia_final
= michael_final
,
173 .dia_setkey
= michael_setkey
} }
177 static int __init
michael_mic_init(void)
179 return crypto_register_alg(&michael_mic_alg
);
183 static void __exit
michael_mic_exit(void)
185 crypto_unregister_alg(&michael_mic_alg
);
189 module_init(michael_mic_init
);
190 module_exit(michael_mic_exit
);
192 MODULE_LICENSE("GPL v2");
193 MODULE_DESCRIPTION("Michael MIC");
194 MODULE_AUTHOR("Jouni Malinen <jkmaline@cc.hut.fi>");