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 int 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 struct aead_request *aead_req;
27 int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm);
28 u8 *__aad;
29
30 aead_req = kzalloc(reqsize + CCM_AAD_LEN, GFP_ATOMIC);
31 if (!aead_req)
32 return -ENOMEM;
33
34 __aad = (u8 *)aead_req + reqsize;
35 memcpy(__aad, aad, CCM_AAD_LEN);
36
37 sg_init_table(sg, 3);
38 sg_set_buf(&sg[0], &__aad[2], be16_to_cpup((__be16 *)__aad));
39 sg_set_buf(&sg[1], data, data_len);
40 sg_set_buf(&sg[2], mic, mic_len);
41
42 aead_request_set_tfm(aead_req, tfm);
43 aead_request_set_crypt(aead_req, sg, sg, data_len, b_0);
44 aead_request_set_ad(aead_req, sg[0].length);
45
46 crypto_aead_encrypt(aead_req);
47 kzfree(aead_req);
48
49 return 0;
50 }
51
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)52 int ieee80211_aes_ccm_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
53 u8 *data, size_t data_len, u8 *mic,
54 size_t mic_len)
55 {
56 struct scatterlist sg[3];
57 struct aead_request *aead_req;
58 int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm);
59 u8 *__aad;
60 int err;
61
62 if (data_len == 0)
63 return -EINVAL;
64
65 aead_req = kzalloc(reqsize + CCM_AAD_LEN, GFP_ATOMIC);
66 if (!aead_req)
67 return -ENOMEM;
68
69 __aad = (u8 *)aead_req + reqsize;
70 memcpy(__aad, aad, CCM_AAD_LEN);
71
72 sg_init_table(sg, 3);
73 sg_set_buf(&sg[0], &__aad[2], be16_to_cpup((__be16 *)__aad));
74 sg_set_buf(&sg[1], data, data_len);
75 sg_set_buf(&sg[2], mic, mic_len);
76
77 aead_request_set_tfm(aead_req, tfm);
78 aead_request_set_crypt(aead_req, sg, sg, data_len + mic_len, b_0);
79 aead_request_set_ad(aead_req, sg[0].length);
80
81 err = crypto_aead_decrypt(aead_req);
82 kzfree(aead_req);
83
84 return err;
85 }
86
ieee80211_aes_key_setup_encrypt(const u8 key[],size_t key_len,size_t mic_len)87 struct crypto_aead *ieee80211_aes_key_setup_encrypt(const u8 key[],
88 size_t key_len,
89 size_t mic_len)
90 {
91 struct crypto_aead *tfm;
92 int err;
93
94 tfm = crypto_alloc_aead("ccm(aes)", 0, CRYPTO_ALG_ASYNC);
95 if (IS_ERR(tfm))
96 return tfm;
97
98 err = crypto_aead_setkey(tfm, key, key_len);
99 if (err)
100 goto free_aead;
101 err = crypto_aead_setauthsize(tfm, mic_len);
102 if (err)
103 goto free_aead;
104
105 return tfm;
106
107 free_aead:
108 crypto_free_aead(tfm);
109 return ERR_PTR(err);
110 }
111
ieee80211_aes_key_free(struct crypto_aead * tfm)112 void ieee80211_aes_key_free(struct crypto_aead *tfm)
113 {
114 crypto_free_aead(tfm);
115 }
116