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/crypto.h>
15#include <linux/err.h>
16#include <crypto/aes.h>
17
18#include <net/mac80211.h>
19#include "key.h"
20#include "aes_ccm.h"
21
22void ieee80211_aes_ccm_encrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
23			       u8 *data, size_t data_len, u8 *mic)
24{
25	struct scatterlist assoc, pt, ct[2];
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_one(&pt, data, data_len);
35	sg_init_one(&assoc, &aad[2], be16_to_cpup((__be16 *)aad));
36	sg_init_table(ct, 2);
37	sg_set_buf(&ct[0], data, data_len);
38	sg_set_buf(&ct[1], mic, IEEE80211_CCMP_MIC_LEN);
39
40	aead_request_set_tfm(aead_req, tfm);
41	aead_request_set_assoc(aead_req, &assoc, assoc.length);
42	aead_request_set_crypt(aead_req, &pt, ct, data_len, b_0);
43
44	crypto_aead_encrypt(aead_req);
45}
46
47int ieee80211_aes_ccm_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
48			      u8 *data, size_t data_len, u8 *mic)
49{
50	struct scatterlist assoc, pt, ct[2];
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_one(&pt, data, data_len);
62	sg_init_one(&assoc, &aad[2], be16_to_cpup((__be16 *)aad));
63	sg_init_table(ct, 2);
64	sg_set_buf(&ct[0], data, data_len);
65	sg_set_buf(&ct[1], mic, IEEE80211_CCMP_MIC_LEN);
66
67	aead_request_set_tfm(aead_req, tfm);
68	aead_request_set_assoc(aead_req, &assoc, assoc.length);
69	aead_request_set_crypt(aead_req, ct, &pt,
70			       data_len + IEEE80211_CCMP_MIC_LEN, b_0);
71
72	return crypto_aead_decrypt(aead_req);
73}
74
75struct crypto_aead *ieee80211_aes_key_setup_encrypt(const u8 key[])
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, WLAN_KEY_LEN_CCMP);
85	if (!err)
86		err = crypto_aead_setauthsize(tfm, IEEE80211_CCMP_MIC_LEN);
87	if (!err)
88		return tfm;
89
90	crypto_free_aead(tfm);
91	return ERR_PTR(err);
92}
93
94void ieee80211_aes_key_free(struct crypto_aead *tfm)
95{
96	crypto_free_aead(tfm);
97}
98