include/net/ah.h

   1 #ifndef _NET_AH_H
   2 #define _NET_AH_H
   3
   4 #include <linux/crypto.h>
   5 #include <net/xfrm.h>
   6
   7 /* This is the maximum truncated ICV length that we know of. */
   8 #define MAX_AH_AUTH_LEN 12
   9
  10 struct ah_data
  11 {
  12         u8                      *key;
  13         int                     key_len;
  14         u8                      *work_icv;
  15         int                     icv_full_len;
  16         int                     icv_trunc_len;
  17
  18         struct crypto_hash      *tfm;
  19 };
  20
  21 static inline int ah_mac_digest(struct ah_data *ahp, struct sk_buff *skb,
  22                                 u8 *auth_data)
  23 {
  24         struct hash_desc desc;
  25         int err;
  26
  27         desc.tfm = ahp->tfm;
  28         desc.flags = 0;
  29
  30         memset(auth_data, 0, ahp->icv_trunc_len);
  31         err = crypto_hash_init(&desc);
  32         if (unlikely(err))
  33                 goto out;
  34         err = skb_icv_walk(skb, &desc, 0, skb->len, crypto_hash_update);
  35         if (unlikely(err))
  36                 goto out;
  37         err = crypto_hash_final(&desc, ahp->work_icv);
  38
  39 out:
  40         return err;
  41 }
  42
  43 #endif