1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * AES-GMAC for IEEE 802.11 BIP-GMAC-128 and BIP-GMAC-256
4 * Copyright 2015, Qualcomm Atheros, Inc.
5 */
6
7 #include <linux/kernel.h>
8 #include <linux/types.h>
9 #include <linux/err.h>
10 #include <crypto/aead.h>
11 #include <crypto/aes.h>
12
13 #include <net/mac80211.h>
14 #include "key.h"
15 #include "aes_gmac.h"
16
ieee80211_aes_gmac(struct crypto_aead * tfm,const u8 * aad,u8 * nonce,const u8 * data,size_t data_len,u8 * mic)17 int ieee80211_aes_gmac(struct crypto_aead *tfm, const u8 *aad, u8 *nonce,
18 const u8 *data, size_t data_len, u8 *mic)
19 {
20 struct scatterlist sg[4];
21 u8 *zero, *__aad, iv[AES_BLOCK_SIZE];
22 struct aead_request *aead_req;
23 int reqsize = sizeof(*aead_req) + crypto_aead_reqsize(tfm);
24
25 if (data_len < GMAC_MIC_LEN)
26 return -EINVAL;
27
28 aead_req = kzalloc(reqsize + GMAC_MIC_LEN + GMAC_AAD_LEN, GFP_ATOMIC);
29 if (!aead_req)
30 return -ENOMEM;
31
32 zero = (u8 *)aead_req + reqsize;
33 __aad = zero + GMAC_MIC_LEN;
34 memcpy(__aad, aad, GMAC_AAD_LEN);
35
36 sg_init_table(sg, 4);
37 sg_set_buf(&sg[0], __aad, GMAC_AAD_LEN);
38 sg_set_buf(&sg[1], data, data_len - GMAC_MIC_LEN);
39 sg_set_buf(&sg[2], zero, GMAC_MIC_LEN);
40 sg_set_buf(&sg[3], mic, GMAC_MIC_LEN);
41
42 memcpy(iv, nonce, GMAC_NONCE_LEN);
43 memset(iv + GMAC_NONCE_LEN, 0, sizeof(iv) - GMAC_NONCE_LEN);
44 iv[AES_BLOCK_SIZE - 1] = 0x01;
45
46 aead_request_set_tfm(aead_req, tfm);
47 aead_request_set_crypt(aead_req, sg, sg, 0, iv);
48 aead_request_set_ad(aead_req, GMAC_AAD_LEN + data_len);
49
50 crypto_aead_encrypt(aead_req);
51 kzfree(aead_req);
52
53 return 0;
54 }
55
ieee80211_aes_gmac_key_setup(const u8 key[],size_t key_len)56 struct crypto_aead *ieee80211_aes_gmac_key_setup(const u8 key[],
57 size_t key_len)
58 {
59 struct crypto_aead *tfm;
60 int err;
61
62 tfm = crypto_alloc_aead("gcm(aes)", 0, CRYPTO_ALG_ASYNC);
63 if (IS_ERR(tfm))
64 return tfm;
65
66 err = crypto_aead_setkey(tfm, key, key_len);
67 if (!err)
68 err = crypto_aead_setauthsize(tfm, GMAC_MIC_LEN);
69 if (!err)
70 return tfm;
71
72 crypto_free_aead(tfm);
73 return ERR_PTR(err);
74 }
75
ieee80211_aes_gmac_key_free(struct crypto_aead * tfm)76 void ieee80211_aes_gmac_key_free(struct crypto_aead *tfm)
77 {
78 crypto_free_aead(tfm);
79 }
80