include/net/ah.h

   1 #ifndef _NET_AH_H
   2 #define _NET_AH_H
   3
   4 #include <net/xfrm.h>
   5
   6 /* This is the maximum truncated ICV length that we know of. */
   7 #define MAX_AH_AUTH_LEN 12
   8
   9 struct ah_data
  10 {
  11         u8                      *key;
  12         int                     key_len;
  13         u8                      *work_icv;
  14         int                     icv_full_len;
  15         int                     icv_trunc_len;
  16
  17         void                    (*icv)(struct ah_data*,
  18                                        struct sk_buff *skb, u8 *icv);
  19
  20         struct crypto_tfm       *tfm;
  21 };
  22
  23 static inline void
  24 ah_hmac_digest(struct ah_data *ahp, struct sk_buff *skb, u8 *auth_data)
  25 {
  26         struct crypto_tfm *tfm = ahp->tfm;
  27
  28         memset(auth_data, 0, ahp->icv_trunc_len);
  29         crypto_hmac_init(tfm, ahp->key, &ahp->key_len);
  30         skb_icv_walk(skb, tfm, 0, skb->len, crypto_hmac_update);
  31         crypto_hmac_final(tfm, ahp->key, &ahp->key_len, ahp->work_icv);
  32         memcpy(auth_data, ahp->work_icv, ahp->icv_trunc_len);
  33 }
  34
  35 #endif