4 #include <linux/crypto.h>
6 #include <asm/scatterlist.h>
8 #define ESP_NUM_FAST_SG 4
12 struct scatterlist sgbuf[ESP_NUM_FAST_SG];
17 int key_len; /* Key length */
18 u8 *ivec; /* ivec buffer */
19 /* ivlen is offset from enc_data, where encrypted data start.
20 * It is logically different of crypto_tfm_alg_ivsize(tfm).
21 * We assume that it is either zero (no ivec), or
22 * >= crypto_tfm_alg_ivsize(tfm). */
24 int padlen; /* 0..255 */
25 struct crypto_tfm *tfm; /* crypto handle */
28 /* Integrity. It is active when icv_full_len != 0 */
31 int key_len; /* Length of the key */
35 void (*icv)(struct esp_data*,
37 int offset, int len, u8 *icv);
38 struct crypto_tfm *tfm;
42 extern int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len);
43 extern int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer);
44 extern void *pskb_put(struct sk_buff *skb, struct sk_buff *tail, int len);
47 esp_hmac_digest(struct esp_data *esp, struct sk_buff *skb, int offset,
48 int len, u8 *auth_data)
50 struct crypto_tfm *tfm = esp->auth.tfm;
51 char *icv = esp->auth.work_icv;
53 memset(auth_data, 0, esp->auth.icv_trunc_len);
54 crypto_hmac_init(tfm, esp->auth.key, &esp->auth.key_len);
55 skb_icv_walk(skb, tfm, offset, len, crypto_hmac_update);
56 crypto_hmac_final(tfm, esp->auth.key, &esp->auth.key_len, icv);
57 memcpy(auth_data, icv, esp->auth.icv_trunc_len);