init repo

client/client.c

@@ -0,0 +1,159 @@
+#include <memory.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include "Diffie_hellman.c"
+#include "aes.h"
+#include <unistd.h>
+
+
+#define AES_DEBUG
+#define MAX_size 256
+#define PORT 8080
+#define Sockaddr struct sockaddr
+
+void recv_msg(int sockfd, char * buf, unsigned char *key){
+    char buff[MAX_size];
+    //add(16)+iv(12)+tag(16)+data
+    unsigned char iv[12],add[16],tag[16];
+    int l=read(sockfd, buff, sizeof(buff));
+    memcpy(add,buff+4,16);
+    memcpy(iv,buff+16+4,12);
+    memset(tag,0,16);
+    int tmp=aes_gcm_ad(key, 32, iv, 12,buff+44+4, l-44-4, add, 16, tag, buf);
+
+}
+
+void send_msg(int sockfd, char * buff, int con_len, unsigned char *key){
+    //add(16)+iv(12)+tag(16)+data
+    unsigned char * cryptbuf=(unsigned char*)malloc(con_len + 44 + 4);
+    memset(cryptbuf, 0, con_len + 44 + 4);
+    //add+iv
+    unsigned char iv[12],add[16],tag[16];
+    memset(tag,0,16);
+    for(int j=0;j<16;j++)
+        add[j]=rand()%256;
+    for(int j=0;j<12;j++)
+        iv[j]=rand()%256;
+    //encrypt
+    int tmp;
+    tmp = aes_gcm_ae(key, 32, iv, 12, buff, con_len, add, 16, cryptbuf + 44 + 4, tag);
+    memcpy(cryptbuf + 4, add, 16);
+    memcpy(cryptbuf + 20, iv, 12);
+    memcpy(cryptbuf + 32, tag, 16);
+    memcpy(cryptbuf, "data", 4);
+    int f;
+    f = write(sockfd, cryptbuf, con_len + 44 + 4);
+}
+
+
+void DH_key_exchange_for_client(int sockfd, unsigned char * key_aes){
+	Dh_key client_key;
+    init_numbers(&client_key);
+	client_key.urand = fopen("/dev/urandom","r");
+    mpz_set_ui(client_key.base, (unsigned long)2);
+	char buff[MAX_size];
+	memset(buff, 0, MAX_size);
+
+	//receive p
+	memset(buff, 0, MAX_size);
+	read(sockfd,buff,sizeof(buff));
+    mpz_set_str(client_key.prime,buff+3,16);
+	gmp_printf("p:%Zd\n",client_key.prime);
+
+    //generate private key a
+	generate_key(32, &client_key);
+	gmp_printf("a:%Zd\n",client_key.private_key);
+
+	//calculate public key A=g^a(mod p)
+	mpz_powm(client_key.public_key, client_key.base, client_key.private_key, client_key.prime);
+	gmp_printf("A:%Zd\n",client_key.public_key);
+
+	//send A
+	bzero(buff, MAX_size);
+	memcpy(buff,"pub",3);
+	mpz_get_str(buff+3,16,client_key.public_key);
+	write(sockfd,buff,sizeof(buff));
+
+	//receive B
+	bzero(buff, MAX_size);
+	read(sockfd,buff,sizeof(buff));
+	mpz_t key_from_s;
+	mpz_init(key_from_s);
+	mpz_set_str(key_from_s,buff+3,16);
+	gmp_printf("B:%Zd\n",key_from_s);
+
+	//calc s=g^(ab)
+    mpz_powm(client_key.key, key_from_s, client_key.private_key, client_key.prime);
+
+	//key -> char*
+	bzero(buff, MAX_size);
+	mpz_get_str(buff,16,client_key.key);
+	memcpy(key_aes,str2hex(buff),32);
+	fclose(client_key.urand);
+	clear_numbers(&client_key);
+}
+
+void func(int sockfd)
+{
+	char buff[MAX_size];
+	int n=0;
+	unsigned char aes_key[32];
+
+    DH_key_exchange_for_client(sockfd, aes_key);
+	printf("\n");
+	print_hex(aes_key, 32);
+	for (;;) {
+		bzero(buff, sizeof(buff));
+		printf("Enter str : ");
+		n = 0;
+		while ((buff[n++] = getchar()) != '\n');
+		send_msg(sockfd, buff, strlen(buff),aes_key);
+
+		bzero(buff, sizeof(buff));
+
+		recv_msg(sockfd, buff, aes_key);
+		printf("From Server : %s", buff);
+
+		if ((strncmp(buff, "exit", 4)) == 0) {
+			printf("Client Exit\n");
+			break;
+		}
+	}
+}
+
+int main(int argc,char **argv)
+{
+	int sockfd, connfd;
+	struct sockaddr_in servaddr, cli;
+
+	//<2F><><EFBFBD><EFBFBD><EFBFBD>׽<EFBFBD><D7BD><EFBFBD>
+	sockfd = socket(AF_INET, SOCK_STREAM, 0);
+	if (sockfd == -1) {
+		printf("socket creation failed\n");
+		exit(0);
+	}
+	else
+		printf("Socket successfully created\n");
+	bzero(&servaddr, sizeof(servaddr));
+
+	//<2F>󶨵<EFBFBD>ַ
+	servaddr.sin_family = AF_INET;
+	servaddr.sin_addr.s_addr = inet_addr(argv[1]);
+	servaddr.sin_port = htons(atoi(argv[2]));
+
+	//<2F><><EFBFBD><EFBFBD>
+	if (connect(sockfd, (Sockaddr*)&servaddr, sizeof(servaddr)) != 0) {
+		printf("connection with the server failed\n");
+		exit(0);
+	}
+	else
+		printf("connected to the server\n");
+
+	//<2F><><EFBFBD><EFBFBD>
+	func(sockfd);
+	close(sockfd);
+}