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 36