问题描述

以下代码使用 HMAC SHA256 生成签名哈希.此代码在 Debian Jessie 和 Ubuntu 16.04(OpenSSL 1.0.2g 2016 年 3 月 1 日)上编译并运行良好.

The code below generates a signed hash using HMAC SHA256. This code compiles and works fine on Debian Jessie and Ubuntu 16.04 (OpenSSL 1.0.2g 1 Mar 2016).

#include <openssl/evp.h>
#include <openssl/hmac.h>
#include <iomanip>
#include <iostream>
#include <string>
#include <sstream>

using namespace std;

string HMAC256(string data, string key)
{
        stringstream ss;
        HMAC_CTX ctx;
        unsigned int  len;
        unsigned char out[EVP_MAX_MD_SIZE];
        HMAC_Init(&ctx, key.c_str(), key.length(), EVP_sha256());
        HMAC_Update(&ctx, (unsigned char*)data.c_str(), data.length());
        HMAC_Final(&ctx, out, &len);
        HMAC_cleanup(&ctx); 
        for (unsigned int i = 0;  i < len;  i++)
        {
          ss << setw(2) << setfill('0') << hex << static_cast<int> (out[i]);
        }
        return ss.str();
}

int main()
{
    cout << HMAC256("AAAA","BBBB") << endl;
    return 0;
}

但是....

在 Debian Stretch 上编译时出现以下错误:

When compiling it on Debian Stretch I get the following error:

hmac256.cpp: In function ‘std::__cxx11::string HMAC256(std::__cxx11::string, std::__cxx11::string)’:
hmac256.cpp:14:18: error: aggregate ‘HMAC_CTX ctx’ has incomplete type and cannot be defined
         HMAC_CTX ctx;
                  ^~~
hmac256.cpp:18:9: warning: ‘int HMAC_Init(HMAC_CTX*, const void*, int, const EVP_MD*)’ is deprecated [-Wdeprecated-declarations]
         HMAC_Init(&ctx, key.c_str(), key.length(), EVP_sha256());
         ^~~~~~~~~
In file included from /usr/include/openssl/hmac.h:13:0,
                 from hmac256.cpp:2:
/usr/include/openssl/hmac.h:28:1: note: declared here
 DEPRECATEDIN_1_1_0(__owur int HMAC_Init(HMAC_CTX *ctx, const void *key, int len,
 ^

这与新的 OpenSSL 版本(OpenSSL 1.1.0f 2017 年 5 月 25 日)有关.

And this has to do with the new OpenSSL version (OpenSSL 1.1.0f 25 May 2017).

问题

为什么我会遇到 OpenSSL 1.1 的问题，以及如何以保持与 OpenSSL 1.0 的向后兼容性的方式解决它?

Why am I experiencing the problem with OpenSSL 1.1, and how to fix it in a way that maintains backward compatibility with OpenSSL 1.0?

推荐答案

关于修复错误，请阅读:升级到 OpenSSL 1.1.0.基本上，您需要创建一个新的 HMAC_CTX，如下所示:

For fixing the error, please read: Upgrade To OpenSSL 1.1.0. Basically, you need to create a new HMAC_CTX as follows:

HMAC_CTX *h = HMAC_CTX_new();
HMAC_Init_ex(h, key, keylen, EVP_sha256(), NULL);
...
HMAC_CTX_free(h);

为了向后兼容，可以考虑使用宏来控制代码块进行编译.

For backward compatibility, you can consider using macros to control the code block to compile.

这篇关于使用 OpenSSL 1.1 的 SHA256 HMAC 未编译的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！