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
21void 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
46int 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
73struct 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
93free_aead:
94	crypto_free_aead(tfm);
95	return ERR_PTR(err);
96}
97
98void ieee80211_aes_key_free(struct crypto_aead *tfm)
99{
100	crypto_free_aead(tfm);
101}
102