使用OpenSSL进行RSA非对称加密(C++版本)

末蓝、 2022-10-12 12:17 180阅读 0赞

### 使用OpenSSL进行RSA非对称加密（C++版本） ###

*   *  运行环境
     *  环境准备
     *  源代码

## 运行环境 ##

源代码运行环境，Widows 10，Qt Creator 5.14.1 MingW。

## 环境准备 ##

关于OpenSSL，既可以下载源代码自己编译，也可以下载已经编译好的库，参见文章：[https://blog.csdn.net/liang19890820/article/details/51658574][https_blog.csdn.net_liang19890820_article_details_51658574]

编译好之后，有如下目录结果：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3JsNTI5MDE0_size_16_color_FFFFFF_t_70_pic_center]  
需在 .pro工程文件中配置引用库和依赖路径：

INCLUDEPATH += $$PWD/openssl/include
    DEPENDPATH += $$PWD/openssl/include
    
    win32:CONFIG(release, debug|release): LIBS += -L$$PWD/openssl/lib/ -llibcrypto
    else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/openssl/lib/ -llibcrypto

## 源代码 ##

#include "openssl/ssl.h"
    #include "openssl/rsa.h"
    
    #define BEGIN_RSA_PUBLIC_KEY    "BEGIN RSA PUBLIC KEY"
    #define BEGIN_PUBLIC_KEY        "BEGIN PUBLIC KEY"
    
    #define PUBLIC_KEY "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCYN5V1VTcOsHxBgccNPgujoNim5wpEaIy4q1zniuth23yKj+kiIJ47ltxBske7FfX4mTzxGKTfAXUacSWlXZ6oihd/wKjPvkjV4RyJjN9sejlofyaZDBXffWE8EL6UhBu3k9O+fPR/7USgqZ5JJE1QkeztigkR8d3Z5gmN7n8K3wIDAQAB"
    
    
    QString rsa_pub_encrypt(const QString &cleardata)
    {
        
        QString pubkey=PUBLIC_KEY;
        pubkey.insert(0, "-----BEGIN PUBLIC KEY-----\n");
        pubkey.append("\n-----END PUBLIC KEY-----\n");
    
        QByteArray pubKeyArry = pubkey.toUtf8();
        uchar* pPubKey = (uchar*)pubKeyArry.data();
        BIO* pKeyBio = BIO_new_mem_buf(pPubKey, pubKeyArry.length());
        if (pKeyBio == NULL){
        
            return "";
        }
    
        RSA* pRsa = RSA_new();
        if ( pubkey.contains(BEGIN_RSA_PUBLIC_KEY) ){
        
            pRsa = PEM_read_bio_RSAPublicKey(pKeyBio, &pRsa, NULL, NULL);
        }else{
        
            pRsa = PEM_read_bio_RSA_PUBKEY(pKeyBio, &pRsa, NULL, NULL);
        }
        if ( pRsa == NULL ){
        
            BIO_free_all(pKeyBio);
            return "";
        }
    
        int nLen = RSA_size(pRsa);
        char* pEncryptBuf = new char[nLen];
        memset(pEncryptBuf, 0, nLen);
    
        QByteArray clearDataArry = cleardata.toUtf8();
        int nClearDataLen = clearDataArry.length();
        uchar* pClearData = (uchar*)clearDataArry.data();
        int nSize = RSA_public_encrypt(nClearDataLen,
                                       pClearData,
                                       (uchar*)pEncryptBuf,
                                       pRsa,
                                       RSA_PKCS1_PADDING);
        QString strEncryptData = "";
        if ( nSize >= 0 ){
        
            QByteArray arry(pEncryptBuf, nSize);
            strEncryptData = arry.toBase64();
        }
    
        // 释放内存
        delete[] pEncryptBuf;
        BIO_free_all(pKeyBio);
        RSA_free(pRsa);
        return strEncryptData;
    }

[https_blog.csdn.net_liang19890820_article_details_51658574]: https://blog.csdn.net/liang19890820/article/details/51658574
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3JsNTI5MDE0_size_16_color_FFFFFF_t_70_pic_center]: /images/20221005/697fcd6040674b18b6d6f35daf5a5506.png