1 /*
2 * Copyright 2014-2015, Qualcomm Atheros, Inc.
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License version 2 as
6 * published by the Free Software Foundation.
7 */
8
9 #include <linux/kernel.h>
10 #include <linux/types.h>
11 #include <linux/err.h>
12 #include <crypto/aead.h>
13
14 #include <net/mac80211.h>
15 #include "key.h"
16 #include "aes_gcm.h"
17
ieee80211_aes_gcm_encrypt(struct crypto_aead * tfm,u8 * j_0,u8 * aad,u8 * data,size_t data_len,u8 * mic)18 int ieee80211_aes_gcm_encrypt(struct crypto_aead *tfm, u8 *j_0, u8 *aad,
19 u8 *data, size_t data_len, u8 *mic)
20 {
21 struct scatterlist sg[3];
22 struct aead_request *aead_req;
23 int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm);
24 u8 *__aad;
25
26 aead_req = kzalloc(reqsize + GCM_AAD_LEN, GFP_ATOMIC);
27 if (!aead_req)
28 return -ENOMEM;
29
30 __aad = (u8 *)aead_req + reqsize;
31 memcpy(__aad, aad, GCM_AAD_LEN);
32
33 sg_init_table(sg, 3);
34 sg_set_buf(&sg[0], &__aad[2], be16_to_cpup((__be16 *)__aad));
35 sg_set_buf(&sg[1], data, data_len);
36 sg_set_buf(&sg[2], mic, IEEE80211_GCMP_MIC_LEN);
37
38 aead_request_set_tfm(aead_req, tfm);
39 aead_request_set_crypt(aead_req, sg, sg, data_len, j_0);
40 aead_request_set_ad(aead_req, sg[0].length);
41
42 crypto_aead_encrypt(aead_req);
43 kzfree(aead_req);
44 return 0;
45 }
46
ieee80211_aes_gcm_decrypt(struct crypto_aead * tfm,u8 * j_0,u8 * aad,u8 * data,size_t data_len,u8 * mic)47 int ieee80211_aes_gcm_decrypt(struct crypto_aead *tfm, u8 *j_0, u8 *aad,
48 u8 *data, size_t data_len, u8 *mic)
49 {
50 struct scatterlist sg[3];
51 struct aead_request *aead_req;
52 int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm);
53 u8 *__aad;
54 int err;
55
56 if (data_len == 0)
57 return -EINVAL;
58
59 aead_req = kzalloc(reqsize + GCM_AAD_LEN, GFP_ATOMIC);
60 if (!aead_req)
61 return -ENOMEM;
62
63 __aad = (u8 *)aead_req + reqsize;
64 memcpy(__aad, aad, GCM_AAD_LEN);
65
66 sg_init_table(sg, 3);
67 sg_set_buf(&sg[0], &__aad[2], be16_to_cpup((__be16 *)__aad));
68 sg_set_buf(&sg[1], data, data_len);
69 sg_set_buf(&sg[2], mic, IEEE80211_GCMP_MIC_LEN);
70
71 aead_request_set_tfm(aead_req, tfm);
72 aead_request_set_crypt(aead_req, sg, sg,
73 data_len + IEEE80211_GCMP_MIC_LEN, j_0);
74 aead_request_set_ad(aead_req, sg[0].length);
75
76 err = crypto_aead_decrypt(aead_req);
77 kzfree(aead_req);
78
79 return err;
80 }
81
ieee80211_aes_gcm_key_setup_encrypt(const u8 key[],size_t key_len)82 struct crypto_aead *ieee80211_aes_gcm_key_setup_encrypt(const u8 key[],
83 size_t key_len)
84 {
85 struct crypto_aead *tfm;
86 int err;
87
88 tfm = crypto_alloc_aead("gcm(aes)", 0, CRYPTO_ALG_ASYNC);
89 if (IS_ERR(tfm))
90 return tfm;
91
92 err = crypto_aead_setkey(tfm, key, key_len);
93 if (err)
94 goto free_aead;
95 err = crypto_aead_setauthsize(tfm, IEEE80211_GCMP_MIC_LEN);
96 if (err)
97 goto free_aead;
98
99 return tfm;
100
101 free_aead:
102 crypto_free_aead(tfm);
103 return ERR_PTR(err);
104 }
105
ieee80211_aes_gcm_key_free(struct crypto_aead * tfm)106 void ieee80211_aes_gcm_key_free(struct crypto_aead *tfm)
107 {
108 crypto_free_aead(tfm);
109 }
110