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                      *work_icv;
  13         int                     icv_full_len;
  14         int                     icv_trunc_len;
  15
  16         struct crypto_hash      *tfm;
  17 };
  18
  19 static inline int ah_mac_digest(struct ah_data *ahp, struct sk_buff *skb,
  20                                 u8 *auth_data)
  21 {
  22         struct hash_desc desc;
  23         int err;
  24
  25         desc.tfm = ahp->tfm;
  26         desc.flags = 0;
  27
  28         memset(auth_data, 0, ahp->icv_trunc_len);
  29         err = crypto_hash_init(&desc);
  30         if (unlikely(err))
  31                 goto out;
  32         err = skb_icv_walk(skb, &desc, 0, skb->len, crypto_hash_update);
  33         if (unlikely(err))
  34                 goto out;
  35         err = crypto_hash_final(&desc, ahp->work_icv);
  36
  37 out:
  38         return err;
  39 }
  40
  41 struct ip_auth_hdr;
  42
  43 static inline struct ip_auth_hdr *ip_auth_hdr(const struct sk_buff *skb)
  44 {
  45         return (struct ip_auth_hdr *)skb_transport_header(skb);
  46 }
  47
  48 #endif