xref: /linux/net/mac80211/aead_api.c (revision 088e88be5a380cc4e81963a9a02815da465d144f)
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 
27 	aead_req = kzalloc(reqsize + aad_len, GFP_ATOMIC);
28 	if (!aead_req)
29 		return -ENOMEM;
30 
31 	__aad = (u8 *)aead_req + reqsize;
32 	memcpy(__aad, aad, aad_len);
33 
34 	sg_init_table(sg, 3);
35 	sg_set_buf(&sg[0], __aad, aad_len);
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 	kzfree(aead_req);
45 
46 	return 0;
47 }
48 
49 int aead_decrypt(struct crypto_aead *tfm, u8 *b_0, u8 *aad, size_t aad_len,
50 		 u8 *data, size_t data_len, u8 *mic)
51 {
52 	size_t mic_len = crypto_aead_authsize(tfm);
53 	struct scatterlist sg[3];
54 	struct aead_request *aead_req;
55 	int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm);
56 	u8 *__aad;
57 	int err;
58 
59 	if (data_len == 0)
60 		return -EINVAL;
61 
62 	aead_req = kzalloc(reqsize + aad_len, GFP_ATOMIC);
63 	if (!aead_req)
64 		return -ENOMEM;
65 
66 	__aad = (u8 *)aead_req + reqsize;
67 	memcpy(__aad, aad, aad_len);
68 
69 	sg_init_table(sg, 3);
70 	sg_set_buf(&sg[0], __aad, aad_len);
71 	sg_set_buf(&sg[1], data, data_len);
72 	sg_set_buf(&sg[2], mic, mic_len);
73 
74 	aead_request_set_tfm(aead_req, tfm);
75 	aead_request_set_crypt(aead_req, sg, sg, data_len + mic_len, b_0);
76 	aead_request_set_ad(aead_req, sg[0].length);
77 
78 	err = crypto_aead_decrypt(aead_req);
79 	kzfree(aead_req);
80 
81 	return err;
82 }
83 
84 struct crypto_aead *
85 aead_key_setup_encrypt(const char *alg, const u8 key[],
86 		       size_t key_len, size_t mic_len)
87 {
88 	struct crypto_aead *tfm;
89 	int err;
90 
91 	tfm = crypto_alloc_aead(alg, 0, CRYPTO_ALG_ASYNC);
92 	if (IS_ERR(tfm))
93 		return tfm;
94 
95 	err = crypto_aead_setkey(tfm, key, key_len);
96 	if (err)
97 		goto free_aead;
98 	err = crypto_aead_setauthsize(tfm, mic_len);
99 	if (err)
100 		goto free_aead;
101 
102 	return tfm;
103 
104 free_aead:
105 	crypto_free_aead(tfm);
106 	return ERR_PTR(err);
107 }
108 
109 void aead_key_free(struct crypto_aead *tfm)
110 {
111 	crypto_free_aead(tfm);
112 }
113