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			       size_t mic_len)
25{
26	struct scatterlist assoc, pt, ct[2];
27
28	char aead_req_data[sizeof(struct aead_request) +
29			   crypto_aead_reqsize(tfm)]
30		__aligned(__alignof__(struct aead_request));
31	struct aead_request *aead_req = (void *) aead_req_data;
32
33	memset(aead_req, 0, sizeof(aead_req_data));
34
35	sg_init_one(&pt, data, data_len);
36	sg_init_one(&assoc, &aad[2], be16_to_cpup((__be16 *)aad));
37	sg_init_table(ct, 2);
38	sg_set_buf(&ct[0], data, data_len);
39	sg_set_buf(&ct[1], mic, mic_len);
40
41	aead_request_set_tfm(aead_req, tfm);
42	aead_request_set_assoc(aead_req, &assoc, assoc.length);
43	aead_request_set_crypt(aead_req, &pt, ct, data_len, b_0);
44
45	crypto_aead_encrypt(aead_req);
46}
47
48int ieee80211_aes_ccm_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad,
49			      u8 *data, size_t data_len, u8 *mic,
50			      size_t mic_len)
51{
52	struct scatterlist assoc, pt, ct[2];
53	char aead_req_data[sizeof(struct aead_request) +
54			   crypto_aead_reqsize(tfm)]
55		__aligned(__alignof__(struct aead_request));
56	struct aead_request *aead_req = (void *) aead_req_data;
57
58	if (data_len == 0)
59		return -EINVAL;
60
61	memset(aead_req, 0, sizeof(aead_req_data));
62
63	sg_init_one(&pt, data, data_len);
64	sg_init_one(&assoc, &aad[2], be16_to_cpup((__be16 *)aad));
65	sg_init_table(ct, 2);
66	sg_set_buf(&ct[0], data, data_len);
67	sg_set_buf(&ct[1], mic, mic_len);
68
69	aead_request_set_tfm(aead_req, tfm);
70	aead_request_set_assoc(aead_req, &assoc, assoc.length);
71	aead_request_set_crypt(aead_req, ct, &pt, data_len + mic_len, b_0);
72
73	return crypto_aead_decrypt(aead_req);
74}
75
76struct crypto_aead *ieee80211_aes_key_setup_encrypt(const u8 key[],
77						    size_t key_len,
78						    size_t mic_len)
79{
80	struct crypto_aead *tfm;
81	int err;
82
83	tfm = crypto_alloc_aead("ccm(aes)", 0, CRYPTO_ALG_ASYNC);
84	if (IS_ERR(tfm))
85		return tfm;
86
87	err = crypto_aead_setkey(tfm, key, key_len);
88	if (err)
89		goto free_aead;
90	err = crypto_aead_setauthsize(tfm, mic_len);
91	if (err)
92		goto free_aead;
93
94	return tfm;
95
96free_aead:
97	crypto_free_aead(tfm);
98	return ERR_PTR(err);
99}
100
101void ieee80211_aes_key_free(struct crypto_aead *tfm)
102{
103	crypto_free_aead(tfm);
104}
105