LXR linux/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
  10struct 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
  19static 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
  37out:
  38        return err;
  39}
  40
  41struct ip_auth_hdr;
  42
  43static 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
  49