2018-2019-1 20165227 20165228 20165237 实验五 通讯协议设计
Linux下OpenSSL的安装与使用
1.两人一组
2.基于Socket实现TCP通信，一人实现服务器，一人实现客户端
3.研究OpenSSL算法，测试对称算法中的AES，非对称算法中的RSA，Hash算法中的MD5
4.选用合适的算法，基于混合密码系统实现对TCP通信进行机密性、完整性保护。
实验步骤
- 在OpenSSL下载地址下载OpenSSL
- 解压OpenSSL源代码
tar xzvf openssl-1.1.0j.tar.gz - 进入源代码目录后
$ ./config
$ make
$ make test
$ make install
- 编写测试代码 test_openssl.c
#include <stdio.h>
#include <openssl/evp.h>
int main(){
OpenSSL_add_all_algorithms();
return 0;
}
- 编译和执行
**L**指定链接库的文件夹地址；
**lcrypto**导入OpenSSL所需包；
**ldl**加载动态库；
**lpthread**：链接POSIX thread库
gcc -o test_openssl test_openssl.c -L/usr/local/ssl/lib -lcrypto -ldl -lpthread
echo $?
结果打印0则表示安装成功
实现TCP通信
server.c：
#include<stdlib.h>
#include<pthread.h>
#include<sys/socket.h>
#include<sys/types.h> //pthread_t , pthread_attr_t and so on.
#include<stdio.h>
#include<netinet/in.h> //structure sockaddr_in
#include<arpa/inet.h> //Func : htonl; htons; ntohl; ntohs
#include<assert.h> //Func :assert
#include<string.h> //Func :memset
#include<unistd.h> //Func :close,write,read
#define SOCK_PORT 9988
#define BUFFER_LENGTH 1024
#define MAX_CONN_LIMIT 512 //MAX connection limit
static void Data_handle(void * sock_fd); //Only can be seen in the file
int main()
{
int sockfd_server;
int sockfd;
int fd_temp;
struct sockaddr_in s_addr_in;
struct sockaddr_in s_addr_client;
int client_length;
sockfd_server = socket(AF_INET,SOCK_STREAM,0); //ipv4,TCP
assert(sockfd_server != -1);
//before bind(), set the attr of structure sockaddr.
memset(&s_addr_in,0,sizeof(s_addr_in));
s_addr_in.sin_family = AF_INET;
s_addr_in.sin_addr.s_addr = htonl(INADDR_ANY); //trans addr from uint32_t host byte order to network byte order.
s_addr_in.sin_port = htons(SOCK_PORT); //trans port from uint16_t host byte order to network byte order.
fd_temp = bind(sockfd_server,(struct scokaddr *)(&s_addr_in),sizeof(s_addr_in));
if(fd_temp == -1)
{
fprintf(stderr,"bind error!
");
exit(1);
}
fd_temp = listen(sockfd_server,MAX_CONN_LIMIT);
if(fd_temp == -1)
{
fprintf(stderr,"listen error!
");
exit(1);
}
while(1)
{
printf("waiting for new connection...
");
pthread_t thread_id;
client_length = sizeof(s_addr_client);
//Block here. Until server accpets a new connection.
sockfd = accept(sockfd_server,(struct sockaddr_*)(&s_addr_client),(socklen_t *)(&client_length));
if(sockfd == -1)
{
fprintf(stderr,"Accept error!
");
continue; //ignore current socket ,continue while loop.
}
printf("A new connection occurs!
");
if(pthread_create(&thread_id,NULL,(void *)(&Data_handle),(void *)(&sockfd)) == -1)
{
fprintf(stderr,"pthread_create error!
");
break; //break while loop
}
}
//Clear
int ret = shutdown(sockfd_server,SHUT_WR); //shut down the all or part of a full-duplex connection.
assert(ret != -1);
printf("Server shuts down
");
return 0;
}
static void Data_handle(void * sock_fd)
{
int fd = *((int *)sock_fd);
int i_recvBytes;
char data_recv[BUFFER_LENGTH];
const char * data_send = "Server has received your request!
";
while(1)
{
printf("waiting for request...
");
//Reset data.
memset(data_recv,0,BUFFER_LENGTH);
i_recvBytes = read(fd,data_recv,BUFFER_LENGTH);
if(i_recvBytes == 0)
{
printf("Maybe the client has closed
");
break;
}
if(i_recvBytes == -1)
{
fprintf(stderr,"read error!
");
break;
}
if(strcmp(data_recv,"quit")==0)
{
printf("Quit command!
");
break; //Break the while loop.
}
printf("read from client : %s
",data_recv);
if(write(fd,data_send,strlen(data_send)) == -1)
{
break;
}
}
//Clear
printf("terminating current client_connection...
");
close(fd); //close a file descriptor.
pthread_exit(NULL); //terminate calling thread!
}
client.c:
#include<stdlib.h>
#include<sys/socket.h>
#include<sys/types.h> //pthread_t , pthread_attr_t and so on.
#include<stdio.h>
#include<netinet/in.h> //structure sockaddr_in
#include<arpa/inet.h> //Func : htonl; htons; ntohl; ntohs
#include<assert.h> //Func :assert
#include<string.h> //Func :memset
#include<unistd.h> //Func :close,write,read
#define SOCK_PORT 9988
#define BUFFER_LENGTH 1024
int main()
{
int sockfd;
int tempfd;
struct sockaddr_in s_addr_in;
char data_send[BUFFER_LENGTH];
char data_recv[BUFFER_LENGTH];
memset(data_send,0,BUFFER_LENGTH);
memset(data_recv,0,BUFFER_LENGTH);
sockfd = socket(AF_INET,SOCK_STREAM,0); //ipv4,TCP
if(sockfd == -1)
{
fprintf(stderr,"socket error!
");
exit(1);
}
//before func connect, set the attr of structure sockaddr.
memset(&s_addr_in,0,sizeof(s_addr_in));
s_addr_in.sin_addr.s_addr = inet_addr("127.0.0.1"); //trans char * to in_addr_t
s_addr_in.sin_family = AF_INET;
s_addr_in.sin_port = htons(SOCK_PORT);
tempfd = connect(sockfd,(struct sockaddr *)(&s_addr_in),sizeof(s_addr_in));
if(tempfd == -1)
{
fprintf(stderr,"Connect error!
");
exit(1);
}
while(1)
{
printf("Please input something you wanna say(input "quit" to quit):
");
gets(data_send);
//scanf("%[^
]",data_send); //or you can also use this
tempfd = write(sockfd,data_send,BUFFER_LENGTH);
if(tempfd == -1)
{
fprintf(stderr,"write error
");
exit(0);
}
if(strcmp(data_send,"quit") == 0) //quit,write the quit request and shutdown client
{
break;
}
else
{
tempfd = read(sockfd,data_recv,BUFFER_LENGTH);
assert(tempfd != -1);
printf("%s
",data_recv);
memset(data_send,0,BUFFER_LENGTH);
memset(data_recv,0,BUFFER_LENGTH);
}
}
int ret = shutdown(sockfd,SHUT_WR); //or you can use func close()--<unistd.h> to close the fd
assert(ret != -1);
return 0;
}
运行结果
在Ubuntu中实现对实验二中的“wc服务器”通过混合密码系统进行防护
- 头文件：
#include <openssl/ssl.h>
#include <openssl/err.h>
- OpenSSL初始化：
int SSL_library_int(void); - 选择会话协议
- 创建会话环境
- 申请SSL会话环境的OpenSSL函数：
SSL_CTX *SSL_CTX_new(SSL_METHOD * method); - 制定证书验证方式的函数：
int SSL_CTX_set_verify(SSL_CTX *ctx,int mode,int(*verify_callback),int(X509_STORE_CTX *)); - 为SSL会话环境加载CA证书的函数:
SSL_CTX_load_verify_location(SSL_CTX *ctx,const char *Cafile,const char *Capath); - 为SSL会话加载用户证书的函数:
SSL_CTX_use_certificate_file(SSL_CTX *ctx, const char *file,int type); - 为SSL会话加载用户私钥的函数:
SSL_CTX_use_PrivateKey_file(SSL_CTX *ctx,const char* file,int type); - 验证私钥和证书是否相符:
int SSL_CTX_check_private_key(SSL_CTX *ctx); - 建立SSL套接字
SSL *SSl_new(SSL_CTX *ctx);//申请一个SSL套接字
int SSL_set_fd(SSL *ssl,int fd);)//绑定读写套接字
int SSL_set_rfd(SSL *ssl,int fd);//绑定只读套接字
int SSL_set_wfd(SSL *ssl,int fd);//绑定只写套接字
- 完成SSL握手
- 进行数据传输
- 结束SSL通信
实验步骤
server.c
#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#include <netinet/in.h>
#include <sys/socket.h>
#include <sys/wait.h>
#include <unistd.h>
#include <arpa/inet.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#define MAXBUF 1024
int main(int argc, char **argv)
{
int sockfd, new_fd;
socklen_t len;
struct sockaddr_in my_addr, their_addr;
unsigned int myport, lisnum;
char buf[MAXBUF + 1];
SSL_CTX *ctx;
if (argv[1])
myport = atoi(argv[1]);
else
myport = 5227;
if (argv[2])
lisnum = atoi(argv[2]);
else
lisnum = 2;
/* SSL 库初始化 */
SSL_library_init();
/* 载入所有 SSL 算法 */
OpenSSL_add_all_algorithms();
/* 载入所有 SSL 错误消息
* */
SSL_load_error_strings();
/* 以 SSL V2 和 V3
* 标准兼容方式产生一个
* SSL_CTX ，即 SSL
* Content Text */
ctx = SSL_CTX_new(SSLv23_server_method());
/* 也可以用
* SSLv2_server_method()
* 或
* SSLv3_server_method()
* 单独表示 V2
* 或 V3标准 */
if (ctx == NULL) {
ERR_print_errors_fp(stdout);
exit(1);
}
/* 载入用户的数字证书，
* 此证书用来发送给客户端。
* 证书里包含有公钥
* */
if (SSL_CTX_use_certificate_file(ctx, argv[3], SSL_FILETYPE_PEM) <= 0) {
ERR_print_errors_fp(stdout);
exit(1);
}
/* 载入用户私钥
* */
if (SSL_CTX_use_PrivateKey_file(ctx, argv[4], SSL_FILETYPE_PEM) <= 0){
ERR_print_errors_fp(stdout);
exit(1);
}
/* 检查用户私钥是否正确
* */
if (!SSL_CTX_check_private_key(ctx)) {
ERR_print_errors_fp(stdout);
exit(1);
}
/* 开启一个
* socket
* 监听
* */
if ((sockfd = socket(PF_INET, SOCK_STREAM, 0)) == -1) {
perror("socket");
exit(1);
} else
printf("socket created
");
bzero(&my_addr, sizeof(my_addr));
my_addr.sin_family = PF_INET;
my_addr.sin_port = htons(myport);
my_addr.sin_addr.s_addr = INADDR_ANY;
if (bind(sockfd, (struct sockaddr *) &my_addr, sizeof(struct sockaddr))
== -1) {
perror("bind");
exit(1);
} else
printf("binded
");
if (listen(sockfd, lisnum) == -1) {
perror("listen");
exit(1);
} else
printf("begin listen
");
while (1) {
SSL *ssl;
len = sizeof(struct sockaddr);
/* 等待客户端连上来
* */
if ((new_fd =
accept(sockfd, (struct sockaddr *) &their_addr,
&len)) == -1) {
perror("accept");
exit(errno);
} else
printf("server: got connection from %s, port %d, socket %d
",
inet_ntoa(their_addr.sin_addr),
ntohs(their_addr.sin_port), new_fd);
/* 基于
* ctx
* 产生一个新的
* SSL
* */
ssl = SSL_new(ctx);
/* 将连接用户的
* socket
* 加入到
* SSL
* */
SSL_set_fd(ssl, new_fd);
/* 建立
* SSL
* 连接
* */
if (SSL_accept(ssl) == -1) {
perror("accept");
close(new_fd);
break;
}
/* 开始处理每个新连接上的数据收发
* */
bzero(buf, MAXBUF + 1);
strcpy(buf, "hello");
/* 发消息给客户端
* */
len = SSL_write(ssl, buf, strlen(buf));
if (len <= 0) {
printf
("消息'%s'发送失败！错误代码是%d，错误信息是'%s'
",
buf, errno, strerror(errno));
goto finish;
} else
printf("消息'%s'发送成功，共发送了%d个字节！
",
buf, len);
bzero(buf, MAXBUF + 1);
/* 接收客户端的消息
* */
len = SSL_read(ssl, buf, MAXBUF);
if (len > 0)
printf("接收消息成功:'%s'，共%d个字节的数据
",
buf, len);
else
printf
("消息接收失败！错误代码是%d，错误信息是'%s'
",
errno, strerror(errno));
/* 处理每个新连接上的数据收发结束
* */
finish:
/* 关闭
* SSL
* 连接
* */
SSL_shutdown(ssl);
/* 释放
* SSL
* */
SSL_free(ssl);
/* 关闭
* socket
* */
close(new_fd);
}
/* 关闭监听的
* socket
* */
close(sockfd);
/* 释放
* CTX
* */
SSL_CTX_free(ctx);
return 0;
}
telent.c:
#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <sys/socket.h>
#include <resolv.h>
#include <stdlib.h>
#include <netinet/in.h>
#include <arpa/inet.h>
#include <unistd.h>
#include <openssl/ssl.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#define MAXBUF 1024
void ShowCerts(SSL * ssl)
{
X509 *cert;
char *line;
cert = SSL_get_peer_certificate(ssl);
if (cert != NULL) {
printf("数字证书信息:
");
line = X509_NAME_oneline(X509_get_subject_name(cert), 0, 0);
printf("证书: %s
", line);
free(line);
line = X509_NAME_oneline(X509_get_issuer_name(cert), 0, 0);
printf("颁发者: %s
", line);
free(line);
X509_free(cert);
} else
printf("无证书信息！
");
}
int main(int argc, char **argv)
{
int sockfd, len;
struct sockaddr_in dest;
char buffer[MAXBUF + 1];
SSL_CTX *ctx;
SSL *ssl;
if (argc != 3) {
printf("参数格式错误！正确用法如下：
%s IP地址 端口
比如: %s 127.0.0.1 80
此程序用来从某个"
"IP 地址的服务器某个端口接收最多 MAXBUF 个字节的消息",
argv[0], argv[0]);
exit(0);
}
/* SSL 库初始化，参看 ssl-server.c 代码 */
SSL_library_init();
OpenSSL_add_all_algorithms();
SSL_load_error_strings();
ctx = SSL_CTX_new(SSLv23_client_method());
if (ctx == NULL) {
ERR_print_errors_fp(stdout);
exit(1);
}
/* 创建一个 socket 用于 tcp
* 通信 */
if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
perror("Socket");
exit(errno);
}
printf("socket created
");
/* 初始化服务器端（对方）的地址和端口信息
* */
bzero(&dest, sizeof(dest));
dest.sin_family = AF_INET;
dest.sin_port = htons(atoi(argv[2]));
if (inet_aton(argv[1], (struct in_addr *) &dest.sin_addr.s_addr) == 0) {
perror(argv[1]);
exit(errno);
}
printf("address created
");
/* 连接服务器
* */
if (connect(sockfd, (struct sockaddr *) &dest, sizeof(dest)) != 0) {
perror("Connect ");
exit(errno);
}
printf("server connected
");
/* 基于
* ctx
* 产生一个新的
* SSL
* */
ssl = SSL_new(ctx);
SSL_set_fd(ssl, sockfd);
/* 建立
* SSL
* 连接
* */
if (SSL_connect(ssl) == -1)
ERR_print_errors_fp(stderr);
else {
printf("Connected with %s encryption
", SSL_get_cipher(ssl));
ShowCerts(ssl);
}
/* 接收对方发过来的消息，最多接收
* MAXBUF
* 个字节
* */
bzero(buffer, MAXBUF + 1);
/* 接收服务器来的消息
* */
len = SSL_read(ssl, buffer, MAXBUF);
if (len > 0)
printf("接收消息成功:'%s'，共%d个字节的数据
",
buffer, len);
else {
printf
("消息接收失败！错误代码是%d，错误信息是'%s'
",
errno, strerror(errno));
goto finish;
}
bzero(buffer, MAXBUF + 1);
strcpy(buffer, "nihao");
/* 发消息给服务器
* */
len = SSL_write(ssl, buffer, strlen(buffer));
if (len < 0)
printf
("消息'%s'发送失败！错误代码是%d，错误信息是'%s'
",
buffer, errno, strerror(errno));
else
printf("消息'%s'发送成功，共发送了%d个字节！
",
buffer, len);
finish:
/* 关闭连接
* */
SSL_shutdown(ssl);
SSL_free(ssl);
close(sockfd);
SSL_CTX_free(ctx);
return 0;
}
- 编译
gcc -o server server.c -I /usr/local/ssl/include -L/usr/local/ssl/lib -lssl -lcrypto -ldl -lpthread
gcc -o telent telent.c -I /usr/local/ssl/include -L/usr/local/ssl/lib -lssl -lcrypto -ldl -lpthread
- 生产私钥和证书
openssl genrsa -out privkey.pem 1024
openssl req -new -x509 -key privkey.pem -out CAcert.pem -days 1095
- 运行
./server 7838 1 CAcert.pem privkey.pem
./telent 127.0.0.1 7838
实验中的问题和解决过程
- 问题1:编译时出现
openssl/evpp.h:错误提示 - 解决方法：原因是在运行
make install命令时没有使用root权限，在运行命令时加上sudo后，重新编译即可。或者通过su直接获取权限运行
实验体会
本次实验让我对OpenSSL的使用有了更为深入的了解。