// ---- rsa非对称加解密 ---- //    
#define KEY_LENGTH  1024               // 密钥长度  
#define PUB_KEY_FILE "pubkey.pem"    // 公钥路径  
#define PRI_KEY_FILE "prikey.pem"    // 私钥路径  
  
// 函数方法生成密钥对   
void generateRSAKey(std::string strKey[2])  
{  
    // 公私密钥对    
    size_t pri_len;  
    size_t pub_len;  
    char *pri_key = NULL;  
    char *pub_key = NULL;  
  
    // 生成密钥对    
    RSA *keypair = RSA_generate_key(KEY_LENGTH, RSA_F4, NULL, NULL);  
  
    BIO *pri = BIO_new(BIO_s_mem());
    BIO *pub = BIO_new(BIO_s_mem()); 
  
    PEM_write_bio_RSAPrivateKey(pri, keypair, NULL, NULL, 0, NULL, NULL);  
    PEM_write_bio_RSAPublicKey(pub, keypair);  
  
    // 获取长度    
    pri_len = BIO_pending(pri);  
    pub_len = BIO_pending(pub); 
  
    // 密钥对读取到字符串
    pri_key = (char *)malloc(pri_len + 1);  
    pub_key = (char *)malloc(pub_len + 1);  
  
    BIO_read(pri, pri_key, pri_len);  
    BIO_read(pub, pub_key, pub_len);  
  
    pri_key[pri_len] = '\0';  
    pub_key[pub_len] = '\0';  
  
    // 存储密钥对    
    strKey[0] = pub_key;  
    strKey[1] = pri_key;  
  
    // 存储到磁盘（这种方式存储的是begin rsa public key/ begin rsa private key开头的）  
    FILE *pubFile = fopen(PUB_KEY_FILE, "w");  
    if (pubFile == NULL)  
    {  
        assert(false);  
        return;  
    }  
    fputs(pub_key, pubFile);  
    fclose(pubFile);  
  
    FILE *priFile = fopen(PRI_KEY_FILE, "w");  
    if (priFile == NULL)  
    {  
        assert(false);  
        return;  
    }  
    fputs(pri_key, priFile);  
    fclose(priFile);  
  
    // 内存释放  
    RSA_free(keypair);  
    BIO_free_all(pub);  
    BIO_free_all(pri);  
  
    free(pri_key);  
    free(pub_key);  
}