extern int ah4_output(struct mbuf *, struct secasvar *);
extern int ah4_calccksum(struct mbuf *, caddr_t, size_t,
const struct ah_algorithm *, struct secasvar *);
extern int ah4_output(struct mbuf *, struct secasvar *);
extern int ah4_calccksum(struct mbuf *, caddr_t, size_t,
const struct ah_algorithm *, struct secasvar *);