xref: /linux/net/mac80211/aead_api.c (revision 7effbd18e496a954540fb6319db0d87d28a70496)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright 2003-2004, Instant802 Networks, Inc.
4  * Copyright 2005-2006, Devicescape Software, Inc.
5  * Copyright 2014-2015, Qualcomm Atheros, Inc.
6  *
7  * Rewrite: Copyright (C) 2013 Linaro Ltd <ard.biesheuvel@linaro.org>
8  */
9 
10 #include <linux/kernel.h>
11 #include <linux/types.h>
12 #include <linux/err.h>
13 #include <linux/scatterlist.h>
14 #include <crypto/aead.h>
15 
16 #include "aead_api.h"
17 
18 int aead_encrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad, size_t aad_len,
19 		 u8 *data, size_t data_len, u8 *mic)
20 {
21 	size_t mic_len = crypto_aead_authsize(tfm);
22 	struct scatterlist sg[3];
23 	struct aead_request *aead_req;
24 	int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm);
25 	u8 *__aad;
26 	int ret;
27 
28 	aead_req = kzalloc(reqsize + aad_len, GFP_ATOMIC);
29 	if (!aead_req)
30 		return -ENOMEM;
31 
32 	__aad = (u8 *)aead_req + reqsize;
33 	memcpy(__aad, aad, aad_len);
34 
35 	sg_init_table(sg, 3);
36 	sg_set_buf(&sg[0], __aad, aad_len);
37 	sg_set_buf(&sg[1], data, data_len);
38 	sg_set_buf(&sg[2], mic, mic_len);
39 
40 	aead_request_set_tfm(aead_req, tfm);
41 	aead_request_set_crypt(aead_req, sg, sg, data_len, b_0);
42 	aead_request_set_ad(aead_req, sg[0].length);
43 
44 	ret = crypto_aead_encrypt(aead_req);
45 	kfree_sensitive(aead_req);
46 
47 	return ret;
48 }
49 
50 int aead_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad, size_t aad_len,
51 		 u8 *data, size_t data_len, u8 *mic)
52 {
53 	size_t mic_len = crypto_aead_authsize(tfm);
54 	struct scatterlist sg[3];
55 	struct aead_request *aead_req;
56 	int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm);
57 	u8 *__aad;
58 	int err;
59 
60 	if (data_len == 0)
61 		return -EINVAL;
62 
63 	aead_req = kzalloc(reqsize + aad_len, GFP_ATOMIC);
64 	if (!aead_req)
65 		return -ENOMEM;
66 
67 	__aad = (u8 *)aead_req + reqsize;
68 	memcpy(__aad, aad, aad_len);
69 
70 	sg_init_table(sg, 3);
71 	sg_set_buf(&sg[0], __aad, aad_len);
72 	sg_set_buf(&sg[1], data, data_len);
73 	sg_set_buf(&sg[2], mic, mic_len);
74 
75 	aead_request_set_tfm(aead_req, tfm);
76 	aead_request_set_crypt(aead_req, sg, sg, data_len + mic_len, b_0);
77 	aead_request_set_ad(aead_req, sg[0].length);
78 
79 	err = crypto_aead_decrypt(aead_req);
80 	kfree_sensitive(aead_req);
81 
82 	return err;
83 }
84 
85 struct crypto_aead *
86 aead_key_setup_encrypt(const char *alg, const u8 key[],
87 		       size_t key_len, size_t mic_len)
88 {
89 	struct crypto_aead *tfm;
90 	int err;
91 
92 	tfm = crypto_alloc_aead(alg, 0, CRYPTO_ALG_ASYNC);
93 	if (IS_ERR(tfm))
94 		return tfm;
95 
96 	err = crypto_aead_setkey(tfm, key, key_len);
97 	if (err)
98 		goto free_aead;
99 	err = crypto_aead_setauthsize(tfm, mic_len);
100 	if (err)
101 		goto free_aead;
102 
103 	return tfm;
104 
105 free_aead:
106 	crypto_free_aead(tfm);
107 	return ERR_PTR(err);
108 }
109 
110 void aead_key_free(struct crypto_aead *tfm)
111 {
112 	crypto_free_aead(tfm);
113 }
114