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