1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
|
/*
* Cryptographic API
*
* Michael MIC (IEEE 802.11i/TKIP) keyed digest
*
* Copyright (c) 2004 Jouni Malinen <jkmaline@cc.hut.fi>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/init.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/crypto.h>
struct michael_mic_ctx {
u8 pending[4];
size_t pending_len;
u32 l, r;
};
static inline u32 xswap(u32 val)
{
return ((val & 0x00ff00ff) << 8) | ((val & 0xff00ff00) >> 8);
}
#define michael_block(l, r) \
do { \
r ^= rol32(l, 17); \
l += r; \
r ^= xswap(l); \
l += r; \
r ^= rol32(l, 3); \
l += r; \
r ^= ror32(l, 2); \
l += r; \
} while (0)
static inline u32 get_le32(const u8 *p)
{
return p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24);
}
static inline void put_le32(u8 *p, u32 v)
{
p[0] = v;
p[1] = v >> 8;
p[2] = v >> 16;
p[3] = v >> 24;
}
static void michael_init(void *ctx)
{
struct michael_mic_ctx *mctx = ctx;
mctx->pending_len = 0;
}
static void michael_update(void *ctx, const u8 *data, unsigned int len)
{
struct michael_mic_ctx *mctx = ctx;
if (mctx->pending_len) {
int flen = 4 - mctx->pending_len;
if (flen > len)
flen = len;
memcpy(&mctx->pending[mctx->pending_len], data, flen);
mctx->pending_len += flen;
data += flen;
len -= flen;
if (mctx->pending_len < 4)
return;
mctx->l ^= get_le32(mctx->pending);
michael_block(mctx->l, mctx->r);
mctx->pending_len = 0;
}
while (len >= 4) {
mctx->l ^= get_le32(data);
michael_block(mctx->l, mctx->r);
data += 4;
len -= 4;
}
if (len > 0) {
mctx->pending_len = len;
memcpy(mctx->pending, data, len);
}
}
static void michael_final(void *ctx, u8 *out)
{
struct michael_mic_ctx *mctx = ctx;
u8 *data = mctx->pending;
/* Last block and padding (0x5a, 4..7 x 0) */
switch (mctx->pending_len) {
case 0:
mctx->l ^= 0x5a;
break;
case 1:
mctx->l ^= data[0] | 0x5a00;
break;
case 2:
mctx->l ^= data[0] | (data[1] << 8) | 0x5a0000;
break;
case 3:
mctx->l ^= data[0] | (data[1] << 8) | (data[2] << 16) |
0x5a000000;
break;
}
michael_block(mctx->l, mctx->r);
/* l ^= 0; */
michael_block(mctx->l, mctx->r);
put_le32(out, mctx->l);
put_le32(out + 4, mctx->r);
}
static int michael_setkey(void *ctx, const u8 *key, unsigned int keylen,
u32 *flags)
{
struct michael_mic_ctx *mctx = ctx;
if (keylen != 8) {
if (flags)
*flags = CRYPTO_TFM_RES_BAD_KEY_LEN;
return -EINVAL;
}
mctx->l = get_le32(key);
mctx->r = get_le32(key + 4);
return 0;
}
static struct crypto_alg michael_mic_alg = {
.cra_name = "michael_mic",
.cra_flags = CRYPTO_ALG_TYPE_DIGEST,
.cra_blocksize = 8,
.cra_ctxsize = sizeof(struct michael_mic_ctx),
.cra_module = THIS_MODULE,
.cra_list = LIST_HEAD_INIT(michael_mic_alg.cra_list),
.cra_u = { .digest = {
.dia_digestsize = 8,
.dia_init = michael_init,
.dia_update = michael_update,
.dia_final = michael_final,
.dia_setkey = michael_setkey } }
};
static int __init michael_mic_init(void)
{
return crypto_register_alg(&michael_mic_alg);
}
static void __exit michael_mic_exit(void)
{
crypto_unregister_alg(&michael_mic_alg);
}
module_init(michael_mic_init);
module_exit(michael_mic_exit);
MODULE_LICENSE("GPL v2");
MODULE_DESCRIPTION("Michael MIC");
MODULE_AUTHOR("Jouni Malinen <jkmaline@cc.hut.fi>");
|
