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#ifndef _NET_ESP_H
#define _NET_ESP_H
#include <linux/crypto.h>
#include <net/xfrm.h>
#include <asm/scatterlist.h>
#define ESP_NUM_FAST_SG 4
struct esp_data
{
struct scatterlist sgbuf[ESP_NUM_FAST_SG];
/* Confidentiality */
struct {
u8 *key; /* Key */
int key_len; /* Key length */
u8 *ivec; /* ivec buffer */
/* ivlen is offset from enc_data, where encrypted data start.
* It is logically different of crypto_tfm_alg_ivsize(tfm).
* We assume that it is either zero (no ivec), or
* >= crypto_tfm_alg_ivsize(tfm). */
int ivlen;
int padlen; /* 0..255 */
struct crypto_tfm *tfm; /* crypto handle */
} conf;
/* Integrity. It is active when icv_full_len != 0 */
struct {
u8 *key; /* Key */
int key_len; /* Length of the key */
u8 *work_icv;
int icv_full_len;
int icv_trunc_len;
void (*icv)(struct esp_data*,
struct sk_buff *skb,
int offset, int len, u8 *icv);
struct crypto_tfm *tfm;
} auth;
};
extern int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len);
extern int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer);
extern void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len);
static inline void
esp_hmac_digest(struct esp_data *esp, struct sk_buff *skb, int offset,
int len, u8 *auth_data)
{
struct crypto_tfm *tfm = esp->auth.tfm;
char *icv = esp->auth.work_icv;
memset(auth_data, 0, esp->auth.icv_trunc_len);
crypto_hmac_init(tfm, esp->auth.key, &esp->auth.key_len);
skb_icv_walk(skb, tfm, offset, len, crypto_hmac_update);
crypto_hmac_final(tfm, esp->auth.key, &esp->auth.key_len, icv);
memcpy(auth_data, icv, esp->auth.icv_trunc_len);
}
#endif
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