blob: f1321b7d650675b725b3e96bdbf7611d3d0b1b42 [file] [log] [blame]
Jouni Malinen8ade5382015-01-24 19:52:09 +02001/*
2 * AES-GMAC for IEEE 802.11 BIP-GMAC-128 and BIP-GMAC-256
3 * Copyright 2015, Qualcomm Atheros, Inc.
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 */
9
10#include <linux/kernel.h>
11#include <linux/types.h>
12#include <linux/crypto.h>
13#include <linux/err.h>
14#include <crypto/aes.h>
15
16#include <net/mac80211.h>
17#include "key.h"
18#include "aes_gmac.h"
19
20#define GMAC_MIC_LEN 16
21#define GMAC_NONCE_LEN 12
22#define AAD_LEN 20
23
24int ieee80211_aes_gmac(struct crypto_aead *tfm, const u8 *aad, u8 *nonce,
25 const u8 *data, size_t data_len, u8 *mic)
26{
27 struct scatterlist sg[3], ct[1];
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 u8 zero[GMAC_MIC_LEN], iv[AES_BLOCK_SIZE];
33
34 if (data_len < GMAC_MIC_LEN)
35 return -EINVAL;
36
37 memset(aead_req, 0, sizeof(aead_req_data));
38
39 memset(zero, 0, GMAC_MIC_LEN);
40 sg_init_table(sg, 3);
41 sg_set_buf(&sg[0], aad, AAD_LEN);
42 sg_set_buf(&sg[1], data, data_len - GMAC_MIC_LEN);
43 sg_set_buf(&sg[2], zero, GMAC_MIC_LEN);
44
45 memcpy(iv, nonce, GMAC_NONCE_LEN);
46 memset(iv + GMAC_NONCE_LEN, 0, sizeof(iv) - GMAC_NONCE_LEN);
47 iv[AES_BLOCK_SIZE - 1] = 0x01;
48
49 sg_init_table(ct, 1);
50 sg_set_buf(&ct[0], mic, GMAC_MIC_LEN);
51
52 aead_request_set_tfm(aead_req, tfm);
53 aead_request_set_assoc(aead_req, sg, AAD_LEN + data_len);
54 aead_request_set_crypt(aead_req, NULL, ct, 0, iv);
55
56 crypto_aead_encrypt(aead_req);
57
58 return 0;
59}
60
61struct crypto_aead *ieee80211_aes_gmac_key_setup(const u8 key[],
62 size_t key_len)
63{
64 struct crypto_aead *tfm;
65 int err;
66
67 tfm = crypto_alloc_aead("gcm(aes)", 0, CRYPTO_ALG_ASYNC);
68 if (IS_ERR(tfm))
69 return tfm;
70
71 err = crypto_aead_setkey(tfm, key, key_len);
72 if (!err)
Jouni Malinen8ade5382015-01-24 19:52:09 +020073 err = crypto_aead_setauthsize(tfm, GMAC_MIC_LEN);
Jouni Malinen82ca6ef2015-03-23 15:41:15 +020074 if (!err)
75 return tfm;
Jouni Malinen8ade5382015-01-24 19:52:09 +020076
77 crypto_free_aead(tfm);
78 return ERR_PTR(err);
79}
80
81void ieee80211_aes_gmac_key_free(struct crypto_aead *tfm)
82{
83 crypto_free_aead(tfm);
84}