Root/
1 | /* |
2 | * AES-128-CMAC with TLen 16 for IEEE 802.11w BIP |
3 | * Copyright 2008, Jouni Malinen <j@w1.fi> |
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/kernel.h> |
11 | #include <linux/types.h> |
12 | #include <linux/crypto.h> |
13 | #include <linux/err.h> |
14 | |
15 | #include <net/mac80211.h> |
16 | #include "key.h" |
17 | #include "aes_cmac.h" |
18 | |
19 | #define AES_BLOCK_SIZE 16 |
20 | #define AES_CMAC_KEY_LEN 16 |
21 | #define CMAC_TLEN 8 /* CMAC TLen = 64 bits (8 octets) */ |
22 | #define AAD_LEN 20 |
23 | |
24 | |
25 | static void gf_mulx(u8 *pad) |
26 | { |
27 | int i, carry; |
28 | |
29 | carry = pad[0] & 0x80; |
30 | for (i = 0; i < AES_BLOCK_SIZE - 1; i++) |
31 | pad[i] = (pad[i] << 1) | (pad[i + 1] >> 7); |
32 | pad[AES_BLOCK_SIZE - 1] <<= 1; |
33 | if (carry) |
34 | pad[AES_BLOCK_SIZE - 1] ^= 0x87; |
35 | } |
36 | |
37 | |
38 | static void aes_128_cmac_vector(struct crypto_cipher *tfm, u8 *scratch, |
39 | size_t num_elem, |
40 | const u8 *addr[], const size_t *len, u8 *mac) |
41 | { |
42 | u8 *cbc, *pad; |
43 | const u8 *pos, *end; |
44 | size_t i, e, left, total_len; |
45 | |
46 | cbc = scratch; |
47 | pad = scratch + AES_BLOCK_SIZE; |
48 | |
49 | memset(cbc, 0, AES_BLOCK_SIZE); |
50 | |
51 | total_len = 0; |
52 | for (e = 0; e < num_elem; e++) |
53 | total_len += len[e]; |
54 | left = total_len; |
55 | |
56 | e = 0; |
57 | pos = addr[0]; |
58 | end = pos + len[0]; |
59 | |
60 | while (left >= AES_BLOCK_SIZE) { |
61 | for (i = 0; i < AES_BLOCK_SIZE; i++) { |
62 | cbc[i] ^= *pos++; |
63 | if (pos >= end) { |
64 | e++; |
65 | pos = addr[e]; |
66 | end = pos + len[e]; |
67 | } |
68 | } |
69 | if (left > AES_BLOCK_SIZE) |
70 | crypto_cipher_encrypt_one(tfm, cbc, cbc); |
71 | left -= AES_BLOCK_SIZE; |
72 | } |
73 | |
74 | memset(pad, 0, AES_BLOCK_SIZE); |
75 | crypto_cipher_encrypt_one(tfm, pad, pad); |
76 | gf_mulx(pad); |
77 | |
78 | if (left || total_len == 0) { |
79 | for (i = 0; i < left; i++) { |
80 | cbc[i] ^= *pos++; |
81 | if (pos >= end) { |
82 | e++; |
83 | pos = addr[e]; |
84 | end = pos + len[e]; |
85 | } |
86 | } |
87 | cbc[left] ^= 0x80; |
88 | gf_mulx(pad); |
89 | } |
90 | |
91 | for (i = 0; i < AES_BLOCK_SIZE; i++) |
92 | pad[i] ^= cbc[i]; |
93 | crypto_cipher_encrypt_one(tfm, pad, pad); |
94 | memcpy(mac, pad, CMAC_TLEN); |
95 | } |
96 | |
97 | |
98 | void ieee80211_aes_cmac(struct crypto_cipher *tfm, u8 *scratch, const u8 *aad, |
99 | const u8 *data, size_t data_len, u8 *mic) |
100 | { |
101 | const u8 *addr[3]; |
102 | size_t len[3]; |
103 | u8 zero[CMAC_TLEN]; |
104 | |
105 | memset(zero, 0, CMAC_TLEN); |
106 | addr[0] = aad; |
107 | len[0] = AAD_LEN; |
108 | addr[1] = data; |
109 | len[1] = data_len - CMAC_TLEN; |
110 | addr[2] = zero; |
111 | len[2] = CMAC_TLEN; |
112 | |
113 | aes_128_cmac_vector(tfm, scratch, 3, addr, len, mic); |
114 | } |
115 | |
116 | |
117 | struct crypto_cipher * ieee80211_aes_cmac_key_setup(const u8 key[]) |
118 | { |
119 | struct crypto_cipher *tfm; |
120 | |
121 | tfm = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC); |
122 | if (IS_ERR(tfm)) |
123 | return NULL; |
124 | |
125 | crypto_cipher_setkey(tfm, key, AES_CMAC_KEY_LEN); |
126 | |
127 | return tfm; |
128 | } |
129 | |
130 | |
131 | void ieee80211_aes_cmac_key_free(struct crypto_cipher *tfm) |
132 | { |
133 | if (tfm) |
134 | crypto_free_cipher(tfm); |
135 | } |
136 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9