1 files changed, 106 insertions, 0 deletions

diff --git a/src/client/cl_net_chan.c b/src/client/cl_net_chan.c
index 395c2d75..45dc56be 100644
--- a/src/client/cl_net_chan.c
+++ b/src/client/cl_net_chan.c
@@ -26,6 +26,108 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 #include "client.h"
 
 /*
+==============
+CL_Netchan_Encode
+
+	// first 12 bytes of the data are always:
+	long serverId;
+	long messageAcknowledge;
+	long reliableAcknowledge;
+
+==============
+*/
+static void CL_Netchan_Encode( msg_t *msg ) {
+	int serverId, messageAcknowledge, reliableAcknowledge;
+	int i, index, srdc, sbit, soob;
+	byte key, *string;
+
+	if ( msg->cursize <= CL_ENCODE_START ) {
+		return;
+	}
+
+	srdc = msg->readcount;
+	sbit = msg->bit;
+	soob = msg->oob;
+
+	msg->bit = 0;
+	msg->readcount = 0;
+	msg->oob = 0;
+
+	serverId = MSG_ReadLong(msg);
+	messageAcknowledge = MSG_ReadLong(msg);
+	reliableAcknowledge = MSG_ReadLong(msg);
+
+	msg->oob = soob;
+	msg->bit = sbit;
+	msg->readcount = srdc;
+
+	string = (byte *)clc.serverCommands[ reliableAcknowledge & (MAX_RELIABLE_COMMANDS-1) ];
+	index = 0;
+	//
+	key = clc.challenge ^ serverId ^ messageAcknowledge;
+	for (i = CL_ENCODE_START; i < msg->cursize; i++) {
+		// modify the key with the last received now acknowledged server command
+		if (!string[index])
+			index = 0;
+		if (string[index] > 127 || (string[index] == '%' && clc.netchan.alternateProtocol == 2)) {
+			key ^= '.' << (i & 1);
+		}
+		else {
+			key ^= string[index] << (i & 1);
+		}
+		index++;
+		// encode the data with this key
+		*(msg->data + i) = (*(msg->data + i)) ^ key;
+	}
+}
+
+/*
+==============
+CL_Netchan_Decode
+
+	// first four bytes of the data are always:
+	long reliableAcknowledge;
+
+==============
+*/
+static void CL_Netchan_Decode( msg_t *msg ) {
+	long reliableAcknowledge, i, index;
+	byte key, *string;
+	int srdc, sbit, soob;
+
+	srdc = msg->readcount;
+	sbit = msg->bit;
+	soob = msg->oob;
+
+	msg->oob = 0;
+
+	reliableAcknowledge = MSG_ReadLong(msg);
+
+	msg->oob = soob;
+	msg->bit = sbit;
+	msg->readcount = srdc;
+
+	string = (byte *) clc.reliableCommands[ reliableAcknowledge & (MAX_RELIABLE_COMMANDS-1) ];
+	index = 0;
+	// xor the client challenge with the netchan sequence number (need something that changes every message)
+	key = clc.challenge ^ LittleLong( *(unsigned *)msg->data );
+	for (i = msg->readcount + CL_DECODE_START; i < msg->cursize; i++) {
+		// modify the key with the last sent and with this message acknowledged client command
+		if (!string[index])
+			index = 0;
+		if (string[index] > 127 || (string[index] == '%' && clc.netchan.alternateProtocol == 2)) {
+			key ^= '.' << (i & 1);
+		}
+		else {
+			key ^= string[index] << (i & 1);
+		}
+		index++;
+		// decode the data with this key
+		*(msg->data + i) = *(msg->data + i) ^ key;
+	}
+}
+
+/*
 =================
 CL_Netchan_TransmitNextFragment
 =================
@@ -49,6 +151,8 @@ CL_Netchan_Transmit
 void CL_Netchan_Transmit( netchan_t *chan, msg_t* msg ) {
 	MSG_WriteByte( msg, clc_EOF );
 
+	if(chan->alternateProtocol != 0)
+		CL_Netchan_Encode( msg );
 	Netchan_Transmit(chan, msg->cursize, msg->data);
 	
 	// Transmit all fragments without delay
@@ -69,6 +173,8 @@ qboolean CL_Netchan_Process( netchan_t *chan, msg_t *msg ) {
 	ret = Netchan_Process( chan, msg );
 	if (!ret)
 		return qfalse;
+	if(chan->alternateProtocol != 0)
+		CL_Netchan_Decode( msg );
 
 	return qtrue;
 }