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/aes_ccm.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/aes_ccm.c')
-rw-r--r-- | net/mac80211/aes_ccm.c | 155 |
1 files changed, 155 insertions, 0 deletions
diff --git a/net/mac80211/aes_ccm.c b/net/mac80211/aes_ccm.c new file mode 100644 index 000000000000..e55569bee7d0 --- /dev/null +++ b/net/mac80211/aes_ccm.c | |||
@@ -0,0 +1,155 @@ | |||
1 | /* | ||
2 | * Copyright 2003-2004, Instant802 Networks, Inc. | ||
3 | * Copyright 2005-2006, Devicescape Software, 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 | #include <linux/crypto.h> | ||
12 | #include <linux/err.h> | ||
13 | #include <asm/scatterlist.h> | ||
14 | |||
15 | #include <net/mac80211.h> | ||
16 | #include "ieee80211_key.h" | ||
17 | #include "aes_ccm.h" | ||
18 | |||
19 | |||
20 | static void ieee80211_aes_encrypt(struct crypto_cipher *tfm, | ||
21 | const u8 pt[16], u8 ct[16]) | ||
22 | { | ||
23 | crypto_cipher_encrypt_one(tfm, ct, pt); | ||
24 | } | ||
25 | |||
26 | |||
27 | static inline void aes_ccm_prepare(struct crypto_cipher *tfm, u8 *b_0, u8 *aad, | ||
28 | u8 *b, u8 *s_0, u8 *a) | ||
29 | { | ||
30 | int i; | ||
31 | |||
32 | ieee80211_aes_encrypt(tfm, b_0, b); | ||
33 | |||
34 | /* Extra Authenticate-only data (always two AES blocks) */ | ||
35 | for (i = 0; i < AES_BLOCK_LEN; i++) | ||
36 | aad[i] ^= b[i]; | ||
37 | ieee80211_aes_encrypt(tfm, aad, b); | ||
38 | |||
39 | aad += AES_BLOCK_LEN; | ||
40 | |||
41 | for (i = 0; i < AES_BLOCK_LEN; i++) | ||
42 | aad[i] ^= b[i]; | ||
43 | ieee80211_aes_encrypt(tfm, aad, a); | ||
44 | |||
45 | /* Mask out bits from auth-only-b_0 */ | ||
46 | b_0[0] &= 0x07; | ||
47 | |||
48 | /* S_0 is used to encrypt T (= MIC) */ | ||
49 | b_0[14] = 0; | ||
50 | b_0[15] = 0; | ||
51 | ieee80211_aes_encrypt(tfm, b_0, s_0); | ||
52 | } | ||
53 | |||
54 | |||
55 | void ieee80211_aes_ccm_encrypt(struct crypto_cipher *tfm, u8 *scratch, | ||
56 | u8 *b_0, u8 *aad, u8 *data, size_t data_len, | ||
57 | u8 *cdata, u8 *mic) | ||
58 | { | ||
59 | int i, j, last_len, num_blocks; | ||
60 | u8 *pos, *cpos, *b, *s_0, *e; | ||
61 | |||
62 | b = scratch; | ||
63 | s_0 = scratch + AES_BLOCK_LEN; | ||
64 | e = scratch + 2 * AES_BLOCK_LEN; | ||
65 | |||
66 | num_blocks = (data_len + AES_BLOCK_LEN - 1) / AES_BLOCK_LEN; | ||
67 | last_len = data_len % AES_BLOCK_LEN; | ||
68 | aes_ccm_prepare(tfm, b_0, aad, b, s_0, b); | ||
69 | |||
70 | /* Process payload blocks */ | ||
71 | pos = data; | ||
72 | cpos = cdata; | ||
73 | for (j = 1; j <= num_blocks; j++) { | ||
74 | int blen = (j == num_blocks && last_len) ? | ||
75 | last_len : AES_BLOCK_LEN; | ||
76 | |||
77 | /* Authentication followed by encryption */ | ||
78 | for (i = 0; i < blen; i++) | ||
79 | b[i] ^= pos[i]; | ||
80 | ieee80211_aes_encrypt(tfm, b, b); | ||
81 | |||
82 | b_0[14] = (j >> 8) & 0xff; | ||
83 | b_0[15] = j & 0xff; | ||
84 | ieee80211_aes_encrypt(tfm, b_0, e); | ||
85 | for (i = 0; i < blen; i++) | ||
86 | *cpos++ = *pos++ ^ e[i]; | ||
87 | } | ||
88 | |||
89 | for (i = 0; i < CCMP_MIC_LEN; i++) | ||
90 | mic[i] = b[i] ^ s_0[i]; | ||
91 | } | ||
92 | |||
93 | |||
94 | int ieee80211_aes_ccm_decrypt(struct crypto_cipher *tfm, u8 *scratch, | ||
95 | u8 *b_0, u8 *aad, u8 *cdata, size_t data_len, | ||
96 | u8 *mic, u8 *data) | ||
97 | { | ||
98 | int i, j, last_len, num_blocks; | ||
99 | u8 *pos, *cpos, *b, *s_0, *a; | ||
100 | |||
101 | b = scratch; | ||
102 | s_0 = scratch + AES_BLOCK_LEN; | ||
103 | a = scratch + 2 * AES_BLOCK_LEN; | ||
104 | |||
105 | num_blocks = (data_len + AES_BLOCK_LEN - 1) / AES_BLOCK_LEN; | ||
106 | last_len = data_len % AES_BLOCK_LEN; | ||
107 | aes_ccm_prepare(tfm, b_0, aad, b, s_0, a); | ||
108 | |||
109 | /* Process payload blocks */ | ||
110 | cpos = cdata; | ||
111 | pos = data; | ||
112 | for (j = 1; j <= num_blocks; j++) { | ||
113 | int blen = (j == num_blocks && last_len) ? | ||
114 | last_len : AES_BLOCK_LEN; | ||
115 | |||
116 | /* Decryption followed by authentication */ | ||
117 | b_0[14] = (j >> 8) & 0xff; | ||
118 | b_0[15] = j & 0xff; | ||
119 | ieee80211_aes_encrypt(tfm, b_0, b); | ||
120 | for (i = 0; i < blen; i++) { | ||
121 | *pos = *cpos++ ^ b[i]; | ||
122 | a[i] ^= *pos++; | ||
123 | } | ||
124 | |||
125 | ieee80211_aes_encrypt(tfm, a, a); | ||
126 | } | ||
127 | |||
128 | for (i = 0; i < CCMP_MIC_LEN; i++) { | ||
129 | if ((mic[i] ^ s_0[i]) != a[i]) | ||
130 | return -1; | ||
131 | } | ||
132 | |||
133 | return 0; | ||
134 | } | ||
135 | |||
136 | |||
137 | struct crypto_cipher * ieee80211_aes_key_setup_encrypt(const u8 key[]) | ||
138 | { | ||
139 | struct crypto_cipher *tfm; | ||
140 | |||
141 | tfm = crypto_alloc_cipher("aes", 0, CRYPTO_ALG_ASYNC); | ||
142 | if (IS_ERR(tfm)) | ||
143 | return NULL; | ||
144 | |||
145 | crypto_cipher_setkey(tfm, key, ALG_CCMP_KEY_LEN); | ||
146 | |||
147 | return tfm; | ||
148 | } | ||
149 | |||
150 | |||
151 | void ieee80211_aes_key_free(struct crypto_cipher *tfm) | ||
152 | { | ||
153 | if (tfm) | ||
154 | crypto_free_cipher(tfm); | ||
155 | } | ||