1 /* Orinoco MIC helpers
2 *
3 * See copyright notice in main.c
4 */
5 #include <linux/kernel.h>
6 #include <linux/string.h>
7 #include <linux/if_ether.h>
8 #include <linux/scatterlist.h>
9 #include <crypto/hash.h>
10
11 #include "orinoco.h"
12 #include "mic.h"
13
14 /********************************************************************/
15 /* Michael MIC crypto setup */
16 /********************************************************************/
orinoco_mic_init(struct orinoco_private * priv)17 int orinoco_mic_init(struct orinoco_private *priv)
18 {
19 priv->tx_tfm_mic = crypto_alloc_shash("michael_mic", 0, 0);
20 if (IS_ERR(priv->tx_tfm_mic)) {
21 printk(KERN_DEBUG "%s: could not allocate "
22 "crypto API michael_mic\n", __func__);
23 priv->tx_tfm_mic = NULL;
24 return -ENOMEM;
25 }
26
27 priv->rx_tfm_mic = crypto_alloc_shash("michael_mic", 0, 0);
28 if (IS_ERR(priv->rx_tfm_mic)) {
29 printk(KERN_DEBUG "%s: could not allocate "
30 "crypto API michael_mic\n", __func__);
31 priv->rx_tfm_mic = NULL;
32 return -ENOMEM;
33 }
34
35 return 0;
36 }
37
orinoco_mic_free(struct orinoco_private * priv)38 void orinoco_mic_free(struct orinoco_private *priv)
39 {
40 if (priv->tx_tfm_mic)
41 crypto_free_shash(priv->tx_tfm_mic);
42 if (priv->rx_tfm_mic)
43 crypto_free_shash(priv->rx_tfm_mic);
44 }
45
orinoco_mic(struct crypto_shash * tfm_michael,u8 * key,u8 * da,u8 * sa,u8 priority,u8 * data,size_t data_len,u8 * mic)46 int orinoco_mic(struct crypto_shash *tfm_michael, u8 *key,
47 u8 *da, u8 *sa, u8 priority,
48 u8 *data, size_t data_len, u8 *mic)
49 {
50 SHASH_DESC_ON_STACK(desc, tfm_michael);
51 u8 hdr[ETH_HLEN + 2]; /* size of header + padding */
52 int err;
53
54 if (tfm_michael == NULL) {
55 printk(KERN_WARNING "%s: tfm_michael == NULL\n", __func__);
56 return -1;
57 }
58
59 /* Copy header into buffer. We need the padding on the end zeroed */
60 memcpy(&hdr[0], da, ETH_ALEN);
61 memcpy(&hdr[ETH_ALEN], sa, ETH_ALEN);
62 hdr[ETH_ALEN * 2] = priority;
63 hdr[ETH_ALEN * 2 + 1] = 0;
64 hdr[ETH_ALEN * 2 + 2] = 0;
65 hdr[ETH_ALEN * 2 + 3] = 0;
66
67 desc->tfm = tfm_michael;
68
69 err = crypto_shash_setkey(tfm_michael, key, MIC_KEYLEN);
70 if (err)
71 return err;
72
73 err = crypto_shash_init(desc);
74 if (err)
75 return err;
76
77 err = crypto_shash_update(desc, hdr, sizeof(hdr));
78 if (err)
79 return err;
80
81 err = crypto_shash_update(desc, data, data_len);
82 if (err)
83 return err;
84
85 err = crypto_shash_final(desc, mic);
86 shash_desc_zero(desc);
87
88 return err;
89 }
90