ssize_t Rio_readp(int fd, void *ptr, size_t nbytes) {
ssize_t n;
if ((n = rio_readp(fd, ptr, nbytes)) < 0) {
if (errno != EPIPE)
unix_error("Rio_readp error");
else {
// printf("Rio_readp: socket has closed with EPIPE\n");
return -1;
}
}
return n;
}
void *nodeTalk(void* args){
int numBytes,clientfd,Bport;
rio_t client;
int num;
clientfd = ((int*)args)[0];
Bport = ((int*)args)[1];
num = ((int*)args)[2];
rio_readinitb(&client,clientfd);
char request[MAXLINE];
numBytes = rio_readp(clientfd,request,MAXLINE);
printf("message received through listening port is %s\n",request);
char ans[MAXLINE];
sprintf(ans,"hello client this is server");
rio_writen(clientfd,ans,sizeof(ans));
close(clientfd);
return NULL;
}
int main(int argc, char *argv[]){
int target_port,local_port;
char *target_ip,*local_ip;
if(argc !=5){
printf("please enter arguments in format:./name target_ip,target_port,local_ip,local_port\n");
}
target_ip = argv[1]; // reserver ip information for future extension
target_port = atoi(argv[2]);
local_ip =argv[3];
local_port = atoi(argv[4]);
// printf("the target ip is :%s\nthe target port is:%d\n",target_ip,target_port);
//start listening
int args[2];
args[0] = local_port;
args[1] = target_port;
pthread_t hear;
Pthread_create(&hear,NULL,start_listen,(void*)args);
Pthread_detach(hear);
//create connectionfd with server
int targetfd;
targetfd = open_clientfd(target_ip,target_port);
if(targetfd < 0){
printf("targetfd error!\n");
return EXIT_FAILURE;
}
char *cmd, *signature;
//hand shake start
//_____________send client hello infromation to server with protocol infromation_______________
char content[MAXLINE];
sprintf(content, "ClientHello,sslv2.0");
rio_writen(targetfd,content,strlen(content));
//receive response from server, confirm protocol
int len;
char answer[MAXLINE];
len = rio_readp(targetfd,answer,MAXLINE);
printf("content received from server is: %s\n",answer);
if(strstr(answer,"ServerHello")!=NULL){
printf("hello ends\n");
}
//______________________DH exchange___________________________
int dh_g = 3;
int dh_b = 7;
int dh_a = 0;
int *g_ptr = &dh_g;
int *a_ptr = &dh_a;
int *b_ptr = &dh_b;
DH_change_client (targetfd, g_ptr, a_ptr,b_ptr);
printf("After DH function: g is %d,a is %d,b is %d\n", dh_g, dh_a, dh_b);
//receive ditial singature from server and authenticate
len = rio_readp(targetfd,answer,MAXLINE);
for(int i = 0;i<strlen(answer)-1;i++){
answer[i] = answer[i]+dh_a;
}
cmd = strtok_r(answer,",",&signature);
printf("signature is %s\n",signature);
if(strcmp(signature,target_ip) == 0){
printf("digital signature verified\n");
}
//create private key-public key pair and send public key to server uisng DH method
int p = 11;
int q = 19;
int public_n;
int public_e;
int private_n;
int private_d;
int *public_n_ptr = &public_n;
int *private_n_ptr = &private_n;
int *public_e_ptr = &public_e;
int *private_d_ptr = &private_d;
RSA_generate(p,q,public_n_ptr,private_n_ptr,public_e_ptr,private_d_ptr);
printf("public <n,e> = <%d,%d>\n", public_n, public_e);
printf("private <n,d> = <%d,%d>\n", private_n, private_d);
memset(content,0,sizeof(content));
sprintf(content,"ClientKeyExchange,RSA %d %d,TLSv1",p,q);
for (int i = 0; i<strlen(content);i++){
content[i] = content[i]+dh_a;
}
rio_writen(targetfd,content,strlen(content));
//__________________first talk______________________
//receive infromation from server and decryption by RSA method
memset(answer, 0, sizeof(answer));
len = rio_readp(targetfd,answer,MAXLINE);
char count_buffer[MAXLINE];
memset(count_buffer, 0, sizeof(count_buffer));
len = rio_readp(targetfd, count_buffer, MAXLINE);
int word_count = atoi(count_buffer);
printf("word count is: %d\n", word_count);
char *decrypt = NULL;
long long *ip2 = (long long *)answer;
decrypt = decryption(ip2, word_count, private_n);
printf("After decryption:%s\n", decrypt);
//______________second talk_______________________
memset(content,0,sizeof(content));
sprintf(content,"ClientFinish");
//encryption
int ans_len = strlen(content);
long long *ip = NULL;
word_count = 0;
int *word_count_ptr = &word_count;
ip = encryption(content,ans_len, word_count_ptr, public_e, public_n);
printf("Before encryption: %s\n", content);
printf("After encryption,send:");
char *ch = (char*)ip;
printf("%s\n", ch);
//send content
rio_writen(targetfd,ch,sizeof(ch)*word_count);
//send word count
memset(content, 0, sizeof(content));
sprintf(content, "%d", word_count);
printf("word count: %s\n", content);
rio_writen(targetfd, content, sizeof(content));
memset(content, 0, sizeof(content));
printf("===============hand shake ends==================\n");
printf("please input your message now\n\n");
//start talking
while (1){
//send information to server
printf("Client:");
memset(content, 0, sizeof(content));
scanf("%s", content);
ans_len = strlen(content);
ip = NULL;
word_count = 0;
word_count_ptr = &word_count;
ip = encryption(content, ans_len, word_count_ptr, public_e, public_n);;
char *ch = (char*)ip;
//send content
rio_writen(targetfd, ch, sizeof(ch)*word_count);
//send word count
memset(content, 0, sizeof(content));
sprintf(content, "%d", word_count);
rio_writen(targetfd, content, sizeof(content));
memset(content, 0, sizeof(content));
//receive information from server
printf("Server:");
memset(answer, 0, sizeof(answer));
len = rio_readp(targetfd, answer, MAXLINE);
if (strcmp(answer, "You end the talk. Sever disconnect.") == 0){
printf("%s\n", answer);
break;
}
memset(count_buffer, 0, sizeof(count_buffer));
len = rio_readp(targetfd, count_buffer, MAXLINE);
word_count = atoi(count_buffer);
decrypt = NULL;
ip2 = (long long *)answer;
decrypt = decryption(ip2, word_count, private_n);
printf("%s\n", decrypt);
}
close (targetfd);
return EXIT_SUCCESS;
}
