drivers/net/wireless/orinoco/mic.c

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