Connection working, auth received, control packets parsed. TODO: Cleanup/filesplit and create login + terminal code.

1 files changed, 147 insertions, 73 deletions

diff --git a/main.c b/main.c
index f5f67fd..5decc47 100644
--- a/main.c
+++ b/main.c
@@ -3,32 +3,149 @@
 #include <netinet/in.h>
 #include <sys/types.h>
 #include <sys/socket.h>
+#include <string.h>
 #include <linux/if_ether.h>
 #include "udp.h"
 
-struct mactelnet_cli_hdr {
+#define DEBUG 0
+
+#define MT_PTYPE_SESSIONSTART 0
+#define MT_PTYPE_DATA 1
+#define MT_PTYPE_ACK 2
+#define MT_PTYPE_END 255
+
+#define MT_CPTYPE_BEGINAUTH 0
+#define MT_CPTYPE_ENCRYPTIONKEY 1
+#define MT_CPTYPE_PASSWORD 2
+#define MT_CPTYPE_USERNAME 3
+#define MT_CPTYPE_TERM_TYPE 4
+#define MT_CPTYPE_TERM_WIDTH 5
+#define MT_CPTYPE_TERM_HEIGHT 6
+#define MT_CPTYPE_PACKET_ERROR 7
+#define MT_CPTYPE_END_AUTH 9
+
+int initPacket(unsigned char *data, unsigned char ptype, unsigned char *src, unsigned char *dst, unsigned short sessionkey, unsigned short counter) {
+
+	// PACKET VERSION
+	data[0] = 1;
+
+	// PACKET TYPE
+	data[1] = ptype;
+
+	// src ethernet address
+	etherAddrton(data + 2, src);
+
+	// dst ethernet address
+	etherAddrton(data + 8, dst);
+
+	data[14] = sessionkey >> 8;
+	data[15] = sessionkey & 0xff;
+
+	data[16] = 0x00;
+	data[17] = 0x15;
+
+	data[18] = (counter >> 24) & 0xff;
+	data[19] = (counter >> 16) & 0xff;
+	data[20] = (counter >> 8) & 0xff;
+	data[21] = counter & 0xff;
+
+	return 22;
+}
+
+int addControlPacket(unsigned char *data, unsigned char cptype, unsigned char *cpdata, int data_len) {
+	data[0] = 0x56;
+	data[1] = 0x34;
+	data[2] = 0x12;
+	data[3] = 0xff;
+
+	// Control packet type
+	data[4] = cptype;
+
+	// Data length
+	data[5] = (data_len >> 24) & 0xff;
+	data[6] = (data_len >> 16) & 0xff;
+	data[7] = (data_len >> 8) & 0xff;
+	data[8] = data_len & 0xff;
+
+	if (data_len) {
+		memcpy(data+9, cpdata, data_len);
+	}
+
+	return 9+data_len;
+}
+
+struct mt_mactelnet_hdr {
 	unsigned char ver;
-	unsigned char packet_type;
+	unsigned char ptype;
 	unsigned char srcaddr[6];
 	unsigned char dstaddr[6];
-	unsigned short sessionkey;
-	unsigned short magic;
+	unsigned short seskey;
 	unsigned int counter;
+	unsigned char *data;
 };
 
-#define MT_PTYPE_SESSIONSTART 0
-#define MT_PTYPE_DATA 1
-#define MT_PTYPE_ACK 2
-#define MT_PTYPE_END 255
+void parsePacket(unsigned char *data, struct mt_mactelnet_hdr *pkthdr) {
+	pkthdr->ver = data[0];
+	pkthdr->ptype = data[1];
+	memcpy(pkthdr->srcaddr, data+2,6);
+	memcpy(pkthdr->dstaddr, data+8,6);
+	pkthdr->seskey = data[16] << 8 | data[17];
+	pkthdr->counter = data[18] << 24 | data[19] << 16 | data[20] << 8 | data[21];
+	pkthdr->data = data + 22;
+}
+
+int sockfd;
+int counter=0;
+unsigned char *src = "00:e0:81:b5:ac:8e";
+unsigned char *dst = "00:0c:42:43:58:a4";
+
+void parseControlPacket(unsigned char *data, int data_len) {
+	unsigned char magic[] = { 0x56, 0x34, 0x12, 0xff };
+	if (memcmp(data,&magic,4) == 0) {
+		if (DEBUG)
+			printf("\tControl packet:\n\t\tType: %d\n\t\tLength: %d\n", data[4], data[5]<<24|data[6]<<16|data[7]<<8|data[8]);
+		if (data_len - 9 - (data[4], data[5]<<24|data[6]<<16|data[7]<<8|data[8]) > 0) {
+			parseControlPacket(data + 9 + (data[4], data[5]<<24|data[6]<<16|data[7]<<8|data[8]), data_len - 9 - (data[4], data[5]<<24|data[6]<<16|data[7]<<8|data[8]));
+		}
+
+		if (data[4] == 1) {
+			printf("Connected. Enter username & password.\n\n"); // TODOD: Teh good shiat
+		}
+	}
+}
+
+void handlePacket(unsigned char *data, int data_len) {
+	struct mt_mactelnet_hdr pkthdr;
+	parsePacket(data, &pkthdr);
+
+	if (DEBUG)
+		printf("Received packet:\n\tVersion %d\n\tType: %d\n\tSesskey: %d\n\tCounter: %d\n\n", pkthdr.ver, pkthdr.ptype, pkthdr.seskey, pkthdr.counter);
+
+	if (pkthdr.ptype == MT_PTYPE_DATA) {
+		char odata[200];
+		int plen=0,result=0;
+		counter += data_len - 22;
+		plen = initPacket(odata, MT_PTYPE_ACK, src, dst, pkthdr.seskey, counter);
+		result = sendCustomUDP(sockfd, src, dst, "213.236.240.252", 20561, "255.255.255.255", 20561, odata, plen);
+		if (DEBUG)
+			printf("ACK: Plen = %d, Send result: %d\n", plen, result);
+
+		if (data_len - 22 > 0) {
+			parseControlPacket(data + 22, data_len - 22);
+		}
+	}
+}
 
 int main (int argc, char **argv) {
-	int sockfd;
 	int outsockfd;
 	int result;
 	char data[200];
 	struct sockaddr_in si_me;
 	char buff[1500];
-	struct mactelnet_cli_hdr outpacket;
+	int plen = 0;
+	int sessionkey=0;
+
+	srand(time(NULL));
 
 	sockfd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
 	outsockfd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
@@ -38,82 +155,39 @@ int main (int argc, char **argv) {
 	si_me.sin_port = htons(20561);
 	si_me.sin_addr.s_addr = htonl(INADDR_ANY);
 
-	if (bind(outsockfd, &si_me, sizeof(si_me))==-1) {
+	if (bind(outsockfd, (struct sockaddr *)&si_me, sizeof(si_me))==-1) {
 		fprintf(stderr, "Error binding to port 20561\n");
 		return 1;
 	}
 
-	outpacket.ver = 1;
-	outpacket.packet_type = MT_PTYPE_SESSIONSTART;
-	etherAddrton(outpacket.srcaddr, "00:e0:81:b5:ac:8e");
-	etherAddrton(outpacket.dstaddr, "00:0c:42:43:58:a4");
-	outpacket.sessionkey = 1234;
-	outpacket.magic = 0x1500;
-	outpacket.counter = 0;
-/*
-	data[0] = 1;
-	data[1] = 0;
-
-	etherAddrton(&data[2], "00:e0:81:b5:ac:8e");
-	etherAddrton(&data[8], "00:0c:42:43:58:a4");
-
-	data[14] = 22;
-	data[15] = 12;
-	data[16] = 0;
-	data[17] = 0x15;
-
-	data[18] = 0;
-	data[19] = 0;
+	sessionkey = rand() % 65535;
 
-	data[20] = 0;
-	data[21] = 0;
-	data[22] = 0;
+	printf("Connecting to %s...\n", dst);
 
-	data[23] = 0;
-*/	
-	result = sendCustomUDP(sockfd, "00:e0:81:b5:ac:8e", "00:0c:42:43:58:a4", "213.236.240.252", 20561, "255.255.255.255", 20561, (unsigned char *)&outpacket, sizeof(outpacket));
-	printf("Send result: %d\n", result);
+	plen = initPacket(data, MT_PTYPE_SESSIONSTART, src, dst, sessionkey, 0);
+	result = sendCustomUDP(sockfd, src, dst, "213.236.240.252", 20561, "255.255.255.255", 20561, data, plen);
+	if (DEBUG)
+		printf("Plen = %d, Send result: %d\n", plen, result);
+	if (DEBUG)
+		printf("Sessionkey: %d\n", sessionkey);
 
 	result = recvfrom(outsockfd, buff, 1400, 0, 0, 0);
-	printf("receive result: %d\n", result);
+	handlePacket(buff, result);
 
+	// TODO: Should resubmit whenever a PTYPE_DATA packet is sent, and an ACK packet with correct datacounter is received
+	// or time out the connection, in all other cases.
+	plen = initPacket(data, MT_PTYPE_DATA, src, dst, sessionkey, 0);
+	plen += addControlPacket(data + plen, MT_CPTYPE_BEGINAUTH, NULL, 0);
 
-	data[0] = 1;
-	data[1] = 1;
-
-	etherAddrton(&data[2], "00:e0:81:b5:ac:8e");
-	etherAddrton(&data[8], "00:0c:42:43:58:a4");
-
-	data[14] = 22;
-	data[15] = 12;
-	data[16] = 0;
-	data[17] = 0x15;
-
-	data[18] = 0;
-	data[19] = 0;
-	data[20] = 0;
-	data[21] = 1;
-
-	data[22] = 0x56;
-	data[23] = 0x34;
-	data[24] = 0x12;
-	data[25] = 0xff;
-
-	// type
-	data[26] = 0;
-
-	//len
-	data[27] = 0;
-	data[28] = 0;
-	data[29] = 0;
-	data[30] = 0;
-	
-	result = sendCustomUDP(sockfd, "00:e0:81:b5:ac:8e", "00:0c:42:43:58:a4", "213.236.240.252", 20561, "255.255.255.255", 20561, data, 31);
-	printf("Send result: %d\n", result);
+	result = sendCustomUDP(sockfd, src, dst, "213.236.240.252", 20561, "255.255.255.255", 20561, data, plen);
+	if (DEBUG)
+		printf("Plen = %d, Send result: %d\n", plen, result);
 
 	result = recvfrom(outsockfd, buff, 1400, 0, 0, 0);
-	printf("receive result: %d\n", result);
+	handlePacket(buff, result);
 
+	result = recvfrom(outsockfd, buff, 1400, 0, 0, 0);
+	handlePacket(buff, result);
 
 	close(sockfd);