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/********************************************************************/
17int 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
38void 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
46int 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}