2018-2019-1 20165227 20165228 20165237 實驗五 通訊協議設計
阿新 • • 發佈：2018-12-16
2018-2019-1 20165227 20165228 20165237 實驗五 通訊協議設計
##Linux下OpenSSL的安裝與使用 1.兩人一組 2.基於Socket實現TCP通訊，一人實現伺服器，一人實現客戶端 3.研究OpenSSL演算法，測試對稱演算法中的AES，非對稱演算法中的RSA，Hash演算法中的MD5 4.選用合適的演算法，基於混合密碼系統實現對TCP通訊進行機密性、完整性保護。 ###實驗步驟
- 在OpenSSL下載地址下載OpenSSL
- 解壓OpenSSL原始碼
tar xzvf openssl-1.1.0j.tar.gz - 進入原始碼目錄後
$ ./config $ make $ make test $ make install
- 編寫測試程式碼 test_openssl.c
#include <stdio.h>
#include <openssl/evp.h>
int main(){
OpenSSL_add_all_algorithms();
return 0;
}
- 編譯和執行
**L**指定連結庫的資料夾地址；
**lcrypto**匯入OpenSSL所需包；
**ldl**載入動態庫；
**lpthread**：連結POSIX thread庫
gcc -o test_openssl test_openssl.c -L/usr/local/ssl/lib -lcrypto -ldl -lpthread echo $?
結果列印0則表示安裝成功 
####實現TCP通訊 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!\n"); exit(1); } fd_temp = listen(sockfd_server,MAX_CONN_LIMIT); if(fd_temp == -1) { fprintf(stderr,"listen error!\n"); exit(1); } while(1) { printf("waiting for new connection...\n"); 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!\n"); continue; //ignore current socket ,continue while loop. } printf("A new connection occurs!\n"); if(pthread_create(&thread_id,NULL,(void *)(&Data_handle),(void *)(&sockfd)) == -1) { fprintf(stderr,"pthread_create error!\n"); 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\n"); 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!\n"; while(1) { printf("waiting for request...\n"); //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\n"); break; } if(i_recvBytes == -1) { fprintf(stderr,"read error!\n"); break; } if(strcmp(data_recv,"quit")==0) { printf("Quit command!\n"); break; //Break the while loop. } printf("read from client : %s\n",data_recv); if(write(fd,data_send,strlen(data_send)) == -1) { break; } } //Clear printf("terminating current client_connection...\n"); 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!\n");
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! \n");
exit(1);
}
while(1)
{
printf("Please input something you wanna say(input \"quit\" to quit):\n");
gets(data_send);
//scanf("%[^\n]",data_send); //or you can also use this
tempfd = write(sockfd,data_send,BUFFER_LENGTH);
if(tempfd == -1)
{
fprintf(stderr,"write error\n");
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\n",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;
}
###執行結果 
##在Ubuntu中實現對實驗二中的“wc伺服器”通過混合密碼系統進行防護
- 標頭檔案：
#include <openssl/ssl.h>
#include <openssl/err.h>
- OpenSSL初始化：
int SSL_library_int(void); - 選擇會話協議
- 建立會話環境
- 申請SSL會話環境的OpenSSL函式：
SSL_CTX *SSL_CTX_new(SSL_METHOD * method); - 制定證書驗證方式的函式：
int SSL_CTX_set_verify(SSL_CTX *ctx,int mode,int(*verify_callback),int(X509_STORE_CTX *)); - 為SSL會話環境載入CA證書的函式:
SSL_CTX_load_verify_location(SSL_CTX *ctx,const char *Cafile,const char *Capath); - 為SSL會話載入使用者證書的函式:
SSL_CTX_use_certificate_file(SSL_CTX *ctx, const char *file,int type); - 為SSL會話載入使用者私鑰的函式:
SSL_CTX_use_PrivateKey_file(SSL_CTX *ctx,const char* file,int type); - 驗證私鑰和證書是否相符:
int SSL_CTX_check_private_key(SSL_CTX *ctx); - 建立SSL套接字
SSL *SSl_new(SSL_CTX *ctx);//申請一個SSL套接字
int SSL_set_fd(SSL *ssl,int fd);)//繫結讀寫套接字
int SSL_set_rfd(SSL *ssl,int fd);//繫結只讀套接字
int SSL_set_wfd(SSL *ssl,int fd);//繫結只寫套接字
- 完成SSL握手
- 進行資料傳輸
- 結束SSL通訊 ###實驗步驟 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 庫初始化 */
SSL_library_init();
/* 載入所有 SSL 演算法 */
OpenSSL_add_all_algorithms();
/* 載入所有 SSL 錯誤訊息
* */
SSL_load_error_strings();
/* 以 SSL V2 和 V3
* 標準相容方式產生一個
* SSL_CTX ，即 SSL
* Content Text */
ctx = SSL_CTX_new(SSLv23_server_method());
/* 也可以用
* SSLv2_server_method()
* 或
* SSLv3_server_method()
* 單獨表示 V2
* 或 V3標準 */
if (ctx == NULL) {
ERR_print_errors_fp(stdout);
exit(1);
}
/* 載入使用者的數字證書，
* 此證書用來發送給客戶端。
* 證書裡包含有公鑰
* */
if (SSL_CTX_use_certificate_file(ctx, argv[3], SSL_FILETYPE_PEM) <= 0) {
ERR_print_errors_fp(stdout);
exit(1);
}
/* 載入使用者私鑰
* */
if (SSL_CTX_use_PrivateKey_file(ctx, argv[4], SSL_FILETYPE_PEM) <= 0){
ERR_print_errors_fp(stdout);
exit(1);
}
/* 檢查使用者私鑰是否正確
* */
if (!SSL_CTX_check_private_key(ctx)) {
ERR_print_errors_fp(stdout);
exit(1);
}
/* 開啟一個
* socket
* 監聽
* */
if ((sockfd = socket(PF_INET, SOCK_STREAM, 0)) == -1) {
perror("socket");
exit(1);
} else
printf("socket created\n");
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\n");
if (listen(sockfd, lisnum) == -1) {
perror("listen");
exit(1);
} else
printf("begin listen\n");
while (1) {
SSL *ssl;
len = sizeof(struct sockaddr);
/* 等待客戶端連上來
* */
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\n",
inet_ntoa(their_addr.sin_addr),
ntohs(their_addr.sin_port), new_fd);
/* 基於
* ctx
* 產生一個新的
* SSL
* */
ssl = SSL_new(ctx);
/* 將連線使用者的
* socket
* 加入到
* SSL
* */
SSL_set_fd(ssl, new_fd);
/* 建立
* SSL
* 連線
* */
if (SSL_accept(ssl) == -1) {
perror("accept");
close(new_fd);
break;
}
/* 開始處理每個新連線上的資料收發
* */
bzero(buf, MAXBUF + 1);
strcpy(buf, "hello");
/* 發訊息給客戶端
* */
len = SSL_write(ssl, buf, strlen(buf));
if (len <= 0) {
printf
("訊息'%s'傳送失敗！錯誤程式碼是%d，錯誤資訊是'%s'\n",
buf, errno, strerror(errno));
goto finish;
} else
printf("訊息'%s'傳送成功，共傳送了%d個位元組！\n",
buf, len);
bzero(buf, MAXBUF + 1);
/* 接收客戶端的訊息
* */
len = SSL_read(ssl, buf, MAXBUF);
if (len > 0)
printf("接收訊息成功:'%s'，共%d個位元組的資料\n",
buf, len);
else
printf
("訊息接收失敗！錯誤程式碼是%d，錯誤資訊是'%s'\n",
errno, strerror(errno));
/* 處理每個新連線上的資料收發結束
* */
finish:
/* 關閉
* SSL
* 連線
* */
SSL_shutdown(ssl);
/* 釋放
* SSL
* */
SSL_free(ssl);
/* 關閉
* socket
* */
close(new_fd);
}
/* 關閉監聽的
* socket
* */
close(sockfd);
/* 釋放
* 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("數字證書資訊:\n");
line = X509_NAME_oneline(X509_get_subject_name(cert), 0, 0);
printf("證書: %s\n", line);
free(line);
line = X509_NAME_oneline(X509_get_issuer_name(cert), 0, 0);
printf("頒發者: %s\n", line);
free(line);
X509_free(cert);
} else
printf("無證書資訊！\n");
}
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("引數格式錯誤！正確用法如下：\n\t\t%s IP地址 埠\n\t比如:\t%s 127.0.0.1 80\n此程式用來從某個"
"IP 地址的伺服器某個埠接收最多 MAXBUF 個位元組的訊息",
argv[0], argv[0]);
exit(0);
}
/* SSL 庫初始化，參看 ssl-server.c 程式碼 */
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);
}
/* 建立一個 socket 用於 tcp
* 通訊 */
if ((sockfd = socket(AF_INET, SOCK_STREAM, 0)) < 0) {
perror("Socket");
exit(errno);
}
printf("socket created\n");
/* 初始化伺服器端（對方）的地址和埠資訊
* */
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\n");
/* 連線伺服器
* */
if (connect(sockfd, (struct sockaddr *) &dest, sizeof(dest)) != 0) {
perror("Connect ");
exit(errno);
}
printf("server connected\n");
/* 基於
* ctx
* 產生一個新的
* SSL
* */
ssl = SSL_new(ctx);
SSL_set_fd(ssl, sockfd);
/* 建立
* SSL
* 連線
* */
if (SSL_connect(ssl) == -1)
ERR_print_errors_fp(stderr);
else {
printf("Connected with %s encryption\n", SSL_get_cipher(ssl));
ShowCerts(ssl);
}
/* 接收對方發過來的訊息，最多接收
* MAXBUF
* 個位元組
* */
bzero(buffer, MAXBUF + 1);
/* 接收伺服器來的訊息
* */
len = SSL_read(ssl, buffer, MAXBUF);
if (len > 0)
printf("接收訊息成功:'%s'，共%d個位元組的資料\n",
buffer, len);
else {
printf
("訊息接收失敗！錯誤程式碼是%d，錯誤資訊是'%s'\n",
errno, strerror(errno));
goto finish;
}
bzero(buffer, MAXBUF + 1);
strcpy(buffer, "nihao");
/* 發訊息給伺服器
* */
len = SSL_write(ssl, buffer, strlen(buffer));
if (len < 0)
printf
("訊息'%s'傳送失敗！錯誤程式碼是%d，錯誤資訊是'%s'\n",
buffer, errno, strerror(errno));
else
printf("訊息'%s'傳送成功，共傳送了%d個位元組！\n",
buffer, len);
finish:
/* 關閉連線
* */
SSL_shutdown(ssl);
SSL_free(ssl);
close(sockfd);
SSL_CTX_free(ctx);
return 0;
}
- 編譯
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
- 生產私鑰和證書
openssl genrsa -out privkey.pem 1024
openssl req -new -x509 -key privkey.pem -out CAcert.pem -days 1095
- 執行
./server 7838 1 CAcert.pem privkey.pem
./telent 127.0.0.1 7838
實驗中的問題和解決過程
- 問題1:編譯時出現
openssl/evpp.h:錯誤提示 - 解決方法：原因是在執行
make install命令時沒有使用root許可權，在執行命令時加上sudo後，重新編譯即可。或者通過su直接獲取許可權執行
實驗體會
本次實驗讓我對OpenSSL的使用有了更為深入的瞭解。