C++ Linux网络通信如何加密

<code>sudo apt-get update
sudo apt-get install libssl-dev</code>

<code>#include <iostream>
#include <cstring>
#include <sys/socket.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
<p>// 初始化OpenSSL库
void InitializeSSL() {
SSL_load_error_strings();
OpenSSL_add_ssl_algorithms();
}</p><p>// 清理OpenSSL库
void CleanupSSL() {
EVP_cleanup();
}</p><p>// 创建SSL上下文
SSL_CTX <em>CreateContext() {
const SSL_METHOD </em>method;
SSL_CTX *ctx;</p><pre class="brush:php;toolbar:false;"><code>method = TLS_client_method();

ctx = SSL_CTX_new(method);
if (!ctx) {
    perror("无法创建SSL上下文");
    ERR_print_errors_fp(stderr);
    exit(EXIT_FAILURE);
}

return ctx;</code>

<code>InitializeSSL();

ctx = CreateContext();

// 设置SSL上下文的选项
SSL_CTX_set_ecdh_auto(ctx, 1);

// 创建套接字
sock = socket(AF_INET, SOCK_STREAM, 0);
if (sock < 0) {
    perror("无法创建套接字");
    exit(EXIT_FAILURE);
}

// 设置服务器地址
memset(&addr, 0, sizeof(addr));
addr.sin_family = AF_INET;
addr.sin_port = htons(atoi(port));
inet_pton(AF_INET, hostname, &addr.sin_addr);

// 连接到服务器
if (connect(sock, (struct sockaddr *)&addr, sizeof(addr)) < 0) {
    perror("连接失败");
    close(sock);
    exit(EXIT_FAILURE);
}

// 创建SSL对象
ssl = SSL_new(ctx);
SSL_set_fd(ssl, sock);

// 建立SSL连接
if (SSL_connect(ssl) <= 0) {
    ERR_print_errors_fp(stderr);
    close(sock);
    exit(EXIT_FAILURE);
}

// 发送和接收数据
const char *message = "Hello, SSL!";
SSL_write(ssl, message, strlen(message));

char buffer[1024];
int bytes_received = SSL_read(ssl, buffer, sizeof(buffer) - 1);
if (bytes_received > 0) {
    buffer[bytes_received] = '\0';
    std::cout << "Received: " << buffer << std::endl;
}

// 关闭连接
SSL_shutdown(ssl);
close(sock);
SSL_free(ssl);
SSL_CTX_free(ctx);
CleanupSSL();

return 0;</code>

<code>g++ -o my_ssl_client my_ssl_client.cpp -lssl -lcrypto</code>