linux内核hmac-sha1使用

最近开发IPSec模块时，需要用到内核中hmac-sha1算法下面为hmac-sha1的简单使用方式

#include <linux/crypto.h>#include <linux/init.h>#include <linux/module.h>#include <linux/kernel.h>#include <crypto/hash.h>#include <linux/scatterlist.h>static void hexdump(char *data, int len){int i = 0;for(; i < len; i++){if((len % 16) == 0)printk("\n");printk("%2x ", data[i]);}printk("\n");}static int __init hmac_sha1(void) {struct crypto_hash  *hash;struct hash_desc *desc;char key[20];struct scatterlist sg;char data[100];char digest[20];memset(data, 0 ,100);memset(key, 0 ,20);hash = crypto_alloc_hash("hmac(sha1)", 0, CRYPTO_ALG_ASYNC);if(IS_ERR(hash)){printk(KERN_INFO "Can't alloc hmac\n");return -2;}desc->tfm = hash;desc->flags = 0;if(crypto_hash_setkey(hash, key, 20)){printk(KERN_INFO "crypto_hash_setkey()\n");return -1;}if((crypto_hash_init(desc))){printk("crypto_hash_init failed\n");return -1;}sg_init_table(&sg, 1);sg_set_buf(&sg, data, sizeof(data));if (crypto_hash_update(desc, &sg, sizeof(data))){printk(KERN_INFO "crypto_hash_update()\n");return -1;}if((crypto_hash_final(desc, digest))){printk("crypto_hash_final\n");return -1;}hexdump(digest, 20);}static void __exit hmac_sha1_exit(void){printk("hmac_exit\n");}module_init(hmac_sha1);module_exit(hmac_sha1_exit);MODULE_LICENSE("GPL");