1 /*
2 * Copyright 2003-2004, Instant802 Networks, Inc.
3 * Copyright 2005-2006, Devicescape Software, Inc.
4 *
5 * Rewrite: Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
12 #include <linux/kernel.h>
13 #include <linux/types.h>
14 #include <linux/err.h>
15 #include <crypto/aead.h>
16
17 #include <net/mac80211.h>
18 #include "key.h"
19 #include "aes_ccm.h"
20
ieee80211_aes_ccm_encrypt(struct crypto_aead * tfm,u8 * b_0,u8 * aad,u8 * data,size_t data_len,u8 * mic,size_t mic_len)21 void ieee80211_aes_ccm_encrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
22 u8 *data, size_t data_len, u8 *mic,
23 size_t mic_len)
24 {
25 struct scatterlist sg[3];
26
27 char aead_req_data[sizeof(struct aead_request) +
28 crypto_aead_reqsize(tfm)]
29 __aligned(__alignof__(struct aead_request));
30 struct aead_request *aead_req = (void *) aead_req_data;
31
32 memset(aead_req, 0, sizeof(aead_req_data));
33
34 sg_init_table(sg, 3);
35 sg_set_buf(&sg[0], &aad[2], be16_to_cpup((__be16 *)aad));
36 sg_set_buf(&sg[1], data, data_len);
37 sg_set_buf(&sg[2], mic, mic_len);
38
39 aead_request_set_tfm(aead_req, tfm);
40 aead_request_set_crypt(aead_req, sg, sg, data_len, b_0);
41 aead_request_set_ad(aead_req, sg[0].length);
42
43 crypto_aead_encrypt(aead_req);
44 }
45
ieee80211_aes_ccm_decrypt(struct crypto_aead * tfm,u8 * b_0,u8 * aad,u8 * data,size_t data_len,u8 * mic,size_t mic_len)46 int ieee80211_aes_ccm_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
47 u8 *data, size_t data_len, u8 *mic,
48 size_t mic_len)
49 {
50 struct scatterlist sg[3];
51 char aead_req_data[sizeof(struct aead_request) +
52 crypto_aead_reqsize(tfm)]
53 __aligned(__alignof__(struct aead_request));
54 struct aead_request *aead_req = (void *) aead_req_data;
55
56 if (data_len == 0)
57 return -EINVAL;
58
59 memset(aead_req, 0, sizeof(aead_req_data));
60
61 sg_init_table(sg, 3);
62 sg_set_buf(&sg[0], &aad[2], be16_to_cpup((__be16 *)aad));
63 sg_set_buf(&sg[1], data, data_len);
64 sg_set_buf(&sg[2], mic, mic_len);
65
66 aead_request_set_tfm(aead_req, tfm);
67 aead_request_set_crypt(aead_req, sg, sg, data_len + mic_len, b_0);
68 aead_request_set_ad(aead_req, sg[0].length);
69
70 return crypto_aead_decrypt(aead_req);
71 }
72
ieee80211_aes_key_setup_encrypt(const u8 key[],size_t key_len,size_t mic_len)73 struct crypto_aead *ieee80211_aes_key_setup_encrypt(const u8 key[],
74 size_t key_len,
75 size_t mic_len)
76 {
77 struct crypto_aead *tfm;
78 int err;
79
80 tfm = crypto_alloc_aead("ccm(aes)", 0, CRYPTO_ALG_ASYNC);
81 if (IS_ERR(tfm))
82 return tfm;
83
84 err = crypto_aead_setkey(tfm, key, key_len);
85 if (err)
86 goto free_aead;
87 err = crypto_aead_setauthsize(tfm, mic_len);
88 if (err)
89 goto free_aead;
90
91 return tfm;
92
93 free_aead:
94 crypto_free_aead(tfm);
95 return ERR_PTR(err);
96 }
97
ieee80211_aes_key_free(struct crypto_aead * tfm)98 void ieee80211_aes_key_free(struct crypto_aead *tfm)
99 {
100 crypto_free_aead(tfm);
101 }
102