openssl 基本算法小例

openssl

openssl支持各种算法,在网络传输中我们需要用到各类算法，尤其是在安全协议里面，hmac算法是必须要用得，dtls协议里面也会用到各类对称算法，下面定义一个类，使用openssl得常用算法中得基本算法。

#pragma once

#include 
#include 
#include 
#include 
#include 
using namespace std;
class c_hmac
{

	string v_key;
	string v_data;
	string v_name;

public:
	c_hmac(string alo_name,string key, string data)
	{
		v_key = key;
		v_data = data;
		v_name = alo_name;
	}
	uint8_t * hmac_algo(unsigned int &len);


};

实现

实现比较简单，版本使用openssl 1.1.1 版

#include "hmac.h"
#include 
#include 
#include 

#pragma comment(lib,"libcrypto.lib")
using namespace std;
#define strcasecmp _stricmp
uint8_t * c_hmac::hmac_algo(unsigned int &len) {
	const EVP_MD * engine = NULL;
	const char *name = v_name.c_str();
	if (strcasecmp("sha512", name) == 0) {
		engine = EVP_sha512();
	}
	else if (strcasecmp("sha256", name) == 0) {
		engine = EVP_sha256();
	}
	else if (strcasecmp("sha1", name) == 0) {
		engine = EVP_sha1();
	}
	else if (strcasecmp("md5", name) == 0) {
		engine = EVP_md5();
	}
	else if (strcasecmp("sha224", name) == 0) {
		engine = EVP_sha224();
	}
	else if (strcasecmp("sha384", name) == 0) {
		engine = EVP_sha384();
	}
	else {
		cout