- 环境配置
- SSL的初始化
这一步主要使用OpenSSL提供的函数设置算法、证书等,一般步骤都固定了的,初始化流程示意图如下所示:
SSL初始化流程图
主要代码为:
[cpp] view plain copy
- SSL_load_error_strings(); /*为打印调试信息作准备*/
- OpenSSL_add_ssl_algorithms(); /*初始化*/
- //meth = TLSv1_server_method(); /*采用什么协议(SSLv2/SSLv3/TLSv1)在此指定*/
- //注意这里是server,客户端那里会是client
- ctx = SSL_CTX_new (TLSv1_server_method());
- CHK_NULL(ctx);
- SSL_CTX_set_verify(ctx,SSL_VERIFY_PEER,NULL); /*验证与否*/
- SSL_CTX_load_verify_locations(ctx,CACERT,NULL); /*若验证,则放置CA证书*/
- if (SSL_CTX_use_certificate_file(ctx, CERTF, SSL_FILETYPE_PEM) <= 0) {
- ERR_print_errors_fp(stderr);
- getchar();
- exit(3);
- }
- if (SSL_CTX_use_PrivateKey_file(ctx, KEYF, SSL_FILETYPE_PEM) <= 0) {
- ERR_print_errors_fp(stdout);
- getchar();
- exit(4);
- }
- if (!SSL_CTX_check_private_key(ctx)) {
- printf("Private key does not match the certificate public keyn");
- getchar();
- exit(5);
- }
- SSL_CTX_set_cipher_list(ctx,"RC4-MD5");
3.SSL连接通信
建立TCP套接字,并且进入监听,当接收到客户端连接请求后,使用accept建立和客户端通信的套接字s,从初始化的SSL_CTX创建一个SSL,将该SSL和与客户端通信的套接字s绑定,然后使用SSL_accept建立和客户端的SSL连接,如果建立成功就可以检查客户端的证书并获取客户端的证书信息,实现相互认证。之后,可以使用异步通信机制处理该SSL连接的消息。原理图如下图所示:
控制台的非异步通信的SSL通信代码如下所示。(非异步通信的代码原理看起来原理更好理解)
服务器端代码
[cpp] view plain copy
- //创建监听套接字
- sListen = socket (AF_INET, SOCK_STREAM, 0);
- if(sListen == INVALID_SOCKET)
- {
- cout << "监听套接字创建失败" << endl;
- exit(0);
- }
- //创建地址
- sockaddr_in sin = {0};
- sin.sin_family = AF_INET;
- sin.sin_addr.s_addr = INADDR_ANY;
- sin.sin_port = htons (PORT);
- //套接字绑定
- err = bind(sListen, (struct sockaddr*) &sin,sizeof(sin));
- if(err == -1)
- {
- cout << "监听套接字绑定失败" << endl;
- exit(0);
- }
- /*接受TCP链接*/
- err = listen (sListen, 5);
- if(err == -1)
- {
- cout << "监听套接字开启监听失败" << endl;
- exit(0);
- }
- //接受客户端连接
- SOCKET sd = accept(sListen, (struct sockaddr *)&sa_cli, (socklen_t*)&client_len);
- if(err == -1)
- {
- cout << "监听套接字accept失败" << endl;
- exit(0);
- }
- closesocket (sListen);
- /*TCP连接已建立,进行服务端的SSL过程. */
- cout << "TCP连接建立,创建SSL连接中....\n" << endl;
- //从初始化的ctx新建SSL
- ssl = SSL_new (ctx);
- if(ssl == NULL)
- {
- cout << "SSL创建失败" << endl;
- exit(0);
- }
- //套接字和SSL绑定
- SSL_set_fd (ssl, sd);
- //SSL连接建立
- err = SSL_accept (ssl);
- if(err == -1)
- {
- cout << "创建SSL连接失败" << endl;
- exit(0);
- }
- else
- {
- cout << "创建SSL连接成功" << endl;
- exit(0);
- }
- /*打印所有加密算法的信息(可选)*/
- cout << "SSL连接算法信息:" << SL_get_cipher (ssl) << endl;
- /*得到服务端的证书并打印些信息(可选) */
- client_cert = SSL_get_peer_certificate (ssl);
- if (client_cert != NULL) {
- cout << "客户端证书:" << endl;
- cout << "subject:" << X509_get_subject_name (client_cert), 0, 0) << endl;
- cout << "issuer:" << X509_NAME_oneline (X509_get_issuer_name (client_cert),0,0) << endl;
- CHK_NULL(str);
- X509_free (client_cert);/*如不再需要,需将证书释放 */
- }
- else cout << "客户端没有证书信息!" << endl; //客户端认证失败
- //SSL通信,用SSL_write,SSL_read代替send和recv
- while(true)
- {
- //接收消息
- err = SSL_read (ssl, buf, sizeof(buf) - 1);
- if(err == -1)
- {
- cout << "SSL_read接收消息失败" << endl;
- exit(0);
- }
- buf[err] = ‘\0‘;
- cout << "【客户端】:" << buf << endl;
- cin >> buf;
- //发送消息
- err = SSL_write(ssl, buf, strlen(ssl));
- if(err == -1)
- {
- cout << "SSL_write发送消息失败" << endl;
- exit(0);
- }
- cout << "【服务器】:" << buf << endl;
- }
- //关闭套接字和ssl
- shutdown (sd,2);
- SSL_free (ssl);
- SSL_CTX_free (ctx);
客户端代码
[cpp] view plain copy
- //
- #include "openssl/rsa.h"
- #include "openssl/crypto.h"
- #include "openssl/x509.h"
- #include "openssl/pem.h"
- #include "openssl/ssl.h"
- #include "openssl/err.h"
- #include "openssl/rand.h"
- #pragma comment(lib, "libeay32.lib")
- #pragma comment(lib, "ssleay32.lib")
- /*所有需要的参数信息都在此处以#define的形式提供*/
- #define CERTF "C:\\client.crt" /*服务端的证书(需经CA签名)*/
- #define KEYF "C:\\client.key" /*服务端的私钥(建议加密存储)*/
- #define CACERT "C:\\ca.crt" /*CA 的证书*/
- #define PORT 7758 /*服务端的端口*/
- int main ()
- {
- int err;
- int sd;
- struct sockaddr_in sa;
- SSL_CTX* ctx;
- SSL* ssl;
- X509* server_cert;
- char* str;
- char buf [4096] = {0};
- char szMsg[4096] = {0};
- //SSL_METHOD *meth;
- int seed_int[100]; /*存放随机序列*/
- WSADATA wsaData;
- if(WSAStartup(MAKEWORD(2,2),&wsaData) != 0){
- printf("WSAStartup()fail:%d\n",GetLastError());
- return -1;
- }
- OpenSSL_add_ssl_algorithms(); /*初始化*/
- SSL_load_error_strings(); /*为打印调试信息作准备*/
- //注意这里是client和和服务器不同
- ctx = SSL_CTX_new (TLSv1_client_method());
- CHK_NULL(ctx);
- SSL_CTX_set_verify(ctx,SSL_VERIFY_PEER,NULL); /*验证与否*/
- SSL_CTX_load_verify_locations(ctx,CACERT,NULL); /*若验证,则放置CA证书*/
- if (SSL_CTX_use_certificate_file(ctx, CERTF, SSL_FILETYPE_PEM) <= 0)
- {
- cout << "客户端证书检查失败!" << endl;
- exit(0);
- }
- if (SSL_CTX_use_PrivateKey_file(ctx, KEYF, SSL_FILETYPE_PEM) <= 0)
- {
- cout << "客户端key检查失败!" << endl;
- exit(0);
- }
- if (!SSL_CTX_check_private_key(ctx))
- {
- cout << "客户端证书和key不匹配!" << endl;
- exit(0);
- }
- /*构建随机数生成机制,WIN32平台必需*/
- srand( (unsigned)time( NULL ) );
- for( int i = 0; i < 100;i++ ) seed_int[i] = rand();
- RAND_seed(seed_int, sizeof(seed_int));
- //创建TCP连接请求
- sd = socket (AF_INET, SOCK_STREAM, 0);
- if(sd == INVALID_SOCKET)
- {
- cout << "套接字创建失败!" << endl;
- exit(0);
- }
- memset(&sa,‘\0‘, sizeof(sa));
- sa.sin_family = AF_INET;
- sa.sin_addr.s_addr = inet_addr ("127.0.0.1");
- sa.sin_port = htons (PORT); /* Server Port number */
- //TCP连接
- err = connect(sd, (struct sockaddr*) &sa,
- if(err == -1)
- {
- cout << "TCP连接失败!" << endl;
- exit(0);
- }
- else
- {
- cout << "SSL连接成功!" << endl;
- exit(0);
- }
- //SSL连接
- //新建SSL
- ssl = SSL_new (ctx);
- if(ssl == NULL)
- {
- cout << "新建SSL失败!" << endl;
- exit(0);
- }
- //套接字和SSL绑定
- SSL_set_fd (ssl, sd);
- //SLL连接
- err = SSL_connect (ssl);
- if(err == -1)
- {
- cout << "SSL连接失败" << endl;
- exit(0);
- }
- else
- {
- cout << "SSL连接成功" << endl;
- exit(0);
- }
- //打印连接信息
- cout << "SSL连接算法信息:" << SSL_get_cipher (ssl) << endl;
- /*得到服务端的证书并打印些信息(可选) */
- server_cert = SSL_get_peer_certificate (ssl);
- if (server_cert != NULL) {
- cout << "服务器证书:" << endl;
- cout << "subject:" << X509_get_subject_name (server_cert), 0, 0) << endl;
- cout << "issuer:" << X509_NAME_oneline (X509_get_issuer_name (server_cert),0,0) << endl;
- CHK_NULL(str);
- X509_free (server_cert);/*如不再需要,需将证书释放 */
- }
- else cout << "服务器没有证书信息!" << endl; //服务器端认证失败
- //SSL通信,用SSL_write,SSL_read代替send和recv
- while(true)
- {
- cout << "请输入要发送的消息:";
- cin >> buf;
- //发送消息
- err = SSL_write(ssl, buf, strlen(ssl));
- if(err == -1)
- {
- cout << "SSL_write发送消息失败" << endl;
- exit(0);
- }
- cout << "【客户端】:" << buf << endl;
- //接收消息
- err = SSL_read (ssl, buf, sizeof(buf) - 1);
- if(err == -1)
- {
- cout << "SSL_read接收消息失败" << endl;
- exit(0);
- }
- buf[err] = ‘\0‘;
- cout << "【服务器】:" << buf << endl;
- }
- /* 收尾工作 */
- SSL_shutdown (ssl);
- shutdown (sd,2);
- SSL_free (ssl);
- SSL_CTX_free (ctx);
- return 0;
- }
时间: 2024-10-27 08:26:40