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,
20					      CRYPTO_ALG_ASYNC);
21	if (IS_ERR(priv->tx_tfm_mic)) {
22		printk(KERN_DEBUG "orinoco_mic_init: could not allocate "
23		       "crypto API michael_mic\n");
24		priv->tx_tfm_mic = NULL;
25		return -ENOMEM;
26	}
27
28	priv->rx_tfm_mic = crypto_alloc_shash("michael_mic", 0,
29					      CRYPTO_ALG_ASYNC);
30	if (IS_ERR(priv->rx_tfm_mic)) {
31		printk(KERN_DEBUG "orinoco_mic_init: could not allocate "
32		       "crypto API michael_mic\n");
33		priv->rx_tfm_mic = NULL;
34		return -ENOMEM;
35	}
36
37	return 0;
38}
39
40void orinoco_mic_free(struct orinoco_private *priv)
41{
42	if (priv->tx_tfm_mic)
43		crypto_free_shash(priv->tx_tfm_mic);
44	if (priv->rx_tfm_mic)
45		crypto_free_shash(priv->rx_tfm_mic);
46}
47
48int orinoco_mic(struct crypto_shash *tfm_michael, u8 *key,
49		u8 *da, u8 *sa, u8 priority,
50		u8 *data, size_t data_len, u8 *mic)
51{
52	SHASH_DESC_ON_STACK(desc, tfm_michael);
53	u8 hdr[ETH_HLEN + 2]; /* size of header + padding */
54	int err;
55
56	if (tfm_michael == NULL) {
57		printk(KERN_WARNING "orinoco_mic: tfm_michael == NULL\n");
58		return -1;
59	}
60
61	/* Copy header into buffer. We need the padding on the end zeroed */
62	memcpy(&hdr[0], da, ETH_ALEN);
63	memcpy(&hdr[ETH_ALEN], sa, ETH_ALEN);
64	hdr[ETH_ALEN * 2] = priority;
65	hdr[ETH_ALEN * 2 + 1] = 0;
66	hdr[ETH_ALEN * 2 + 2] = 0;
67	hdr[ETH_ALEN * 2 + 3] = 0;
68
69	desc->tfm = tfm_michael;
70	desc->flags = 0;
71
72	err = crypto_shash_setkey(tfm_michael, key, MIC_KEYLEN);
73	if (err)
74		return err;
75
76	err = crypto_shash_init(desc);
77	if (err)
78		return err;
79
80	err = crypto_shash_update(desc, hdr, sizeof(hdr));
81	if (err)
82		return err;
83
84	err = crypto_shash_update(desc, data, data_len);
85	if (err)
86		return err;
87
88	err = crypto_shash_final(desc, mic);
89	shash_desc_zero(desc);
90
91	return err;
92}