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 <linux/crypto.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_hash("michael_mic", 0, 0);
20	if (IS_ERR(priv->tx_tfm_mic)) {
21		printk(KERN_DEBUG "orinoco_mic_init: could not allocate "
22		       "crypto API michael_mic\n");
23		priv->tx_tfm_mic = NULL;
24		return -ENOMEM;
25	}
26
27	priv->rx_tfm_mic = crypto_alloc_hash("michael_mic", 0, 0);
28	if (IS_ERR(priv->rx_tfm_mic)) {
29		printk(KERN_DEBUG "orinoco_mic_init: could not allocate "
30		       "crypto API michael_mic\n");
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_hash(priv->tx_tfm_mic);
42	if (priv->rx_tfm_mic)
43		crypto_free_hash(priv->rx_tfm_mic);
44}
45
46int orinoco_mic(struct crypto_hash *tfm_michael, u8 *key,
47		u8 *da, u8 *sa, u8 priority,
48		u8 *data, size_t data_len, u8 *mic)
49{
50	struct hash_desc desc;
51	struct scatterlist sg[2];
52	u8 hdr[ETH_HLEN + 2]; /* size of header + padding */
53
54	if (tfm_michael == NULL) {
55		printk(KERN_WARNING "orinoco_mic: tfm_michael == NULL\n");
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	/* Use scatter gather to MIC header and data in one go */
68	sg_init_table(sg, 2);
69	sg_set_buf(&sg[0], hdr, sizeof(hdr));
70	sg_set_buf(&sg[1], data, data_len);
71
72	if (crypto_hash_setkey(tfm_michael, key, MIC_KEYLEN))
73		return -1;
74
75	desc.tfm = tfm_michael;
76	desc.flags = 0;
77	return crypto_hash_digest(&desc, sg, data_len + sizeof(hdr),
78				  mic);
79}
80