From c772fb98d178ab3f5ecb71bae051996d46daf541 Mon Sep 17 00:00:00 2001
From: Alibek Omarov <a1ba.omarov@gmail.com>
Date: Sat, 7 Feb 2026 20:34:52 +0500
Subject: [PATCH] engine: client: salt xashid with server address

---
 engine/client/cl_main.c        | 15 ++++++-----
 engine/client/client.h         |  2 +-
 engine/client/identification.c | 46 +++++++++++++++++++++++-----------
 3 files changed, 41 insertions(+), 22 deletions(-)

diff --git a/engine/client/cl_main.c b/engine/client/cl_main.c
index d7eba21b..6e7a1ef7 100644
--- a/engine/client/cl_main.c
+++ b/engine/client/cl_main.c
@@ -1054,7 +1054,8 @@ static void CL_GetCDKey( char *protinfo, size_t protinfosize )
 
 static void CL_WriteSteamTicket( sizebuf_t *send )
 {
-	const char *s;
+	string key;
+	netadr_t adr = { .type = NA_LOOPBACK, }; // goldsrc servers don't get unique key as xashid isn't sent raw to them
 	uint32_t crc;
 	char buf[768] = { 0 }; // setti and steamemu return 768
 	int i = sizeof( buf );
@@ -1072,11 +1073,11 @@ static void CL_WriteSteamTicket( sizebuf_t *send )
 	//	return;
 	//}
 
-	s = ID_GetMD5();
+	ID_GetMD5ForAddress( key, adr, sizeof( key ));
 	CRC32_Init( &crc );
-	CRC32_ProcessBuffer( &crc, s, Q_strlen( s ));
+	CRC32_ProcessBuffer( &crc, key, Q_strlen( key ));
 	crc = CRC32_Final( crc );
-	i = GenerateRevEmu2013( buf, s, crc );
+	i = GenerateRevEmu2013( buf, key, crc );
 	MSG_WriteBytes( send, buf, i );
 
 	// RevEmu2013: pTicket[1] = revHash (low), pTicket[5] = 0x01100001 (high)
@@ -1095,7 +1096,6 @@ connect.
 static void CL_SendConnectPacket( connprotocol_t proto, int challenge )
 {
 	char protinfo[MAX_INFO_STRING];
-	const char *key = ID_GetMD5();
 	netadr_t adr = { 0 };
 	int input_devices;
 	netadrtype_t adrtype;
@@ -1158,6 +1158,9 @@ static void CL_SendConnectPacket( connprotocol_t proto, int challenge )
 	{
 		const char *qport = Cvar_VariableString( "net_qport" );
 		int extensions = NET_EXT_SPLITSIZE;
+		string key;
+
+		ID_GetMD5ForAddress( key, adr, sizeof( key ));
 
 		// reset nickname from cvar value
 		Info_SetValueForKey( cls.userinfo, "name", name.string, sizeof( cls.userinfo ));
@@ -1167,7 +1170,7 @@ static void CL_SendConnectPacket( connprotocol_t proto, int challenge )
 
 		Info_SetValueForKey( protinfo, "uuid", key, sizeof( protinfo ));
 		Info_SetValueForKey( protinfo, "qport", qport, sizeof( protinfo ));
-		Info_SetValueForKeyf( protinfo, "ext", sizeof( protinfo ), "%d", extensions);
+		Info_SetValueForKeyf( protinfo, "ext", sizeof( protinfo ), "%d", extensions );
 
 		Netchan_OutOfBandPrint( NS_CLIENT, adr, C2S_CONNECT" %i %i \"%s\" \"%s\"\n", PROTOCOL_VERSION, challenge, protinfo, cls.userinfo );
 		Con_Printf( "Trying to connect with modern protocol\n" );
diff --git a/engine/client/client.h b/engine/client/client.h
index 808dc52a..73dbb624 100644
--- a/engine/client/client.h
+++ b/engine/client/client.h
@@ -1228,7 +1228,7 @@ void OSK_Draw( void );
 // identification.c
 //
 void ID_Init( void );
-const char *ID_GetMD5( void );
+void ID_GetMD5ForAddress( char *key, netadr_t adr, size_t size );
 
 extern rgba_t g_color_table[8];
 extern triangleapi_t gTriApi;
diff --git a/engine/client/identification.c b/engine/client/identification.c
index fefbaee7..336205cf 100644
--- a/engine/client/identification.c
+++ b/engine/client/identification.c
@@ -22,8 +22,6 @@ GNU General Public License for more details.
 #include <io.h>
 #endif
 
-static char id_md5[33];
-
 /*
 ==========================================================
 
@@ -634,17 +632,42 @@ static void ID_Check( void )
 #endif
 }
 
-const char *ID_GetMD5( void )
+void ID_GetMD5ForAddress( char *key, netadr_t adr, size_t size )
 {
-	return id_md5;
+	MD5Context_t ctx;
+	byte buf[32], md5[16];
+	size_t bufsize = 0;
+	bloomfilter_t value = id;
+
+	switch( NET_NetadrType( &adr ))
+	{
+	// local server case
+	case NA_IP:
+		memcpy( buf, adr.ip, sizeof( adr.ip ));
+		memcpy( buf + sizeof( adr.ip ), &adr.port, sizeof( adr.port ));
+		bufsize = sizeof( adr.ip ) + sizeof( adr.port );
+		break;
+	case NA_IP6:
+		NET_NetadrToIP6Bytes( buf, &adr );
+		memcpy( buf + 16, &adr.port, sizeof( adr.port ));
+		bufsize = 16 + sizeof( adr.port );
+		break;
+	default:
+		bufsize = 0;
+		break;
+	}
+
+	if( bufsize != 0 )
+		value = BloomFilter_Process( buf, bufsize );
+
+	MD5Init( &ctx );
+	MD5Update( &ctx, (byte *)&value, sizeof( value ));
+	MD5Final( md5, &ctx );
+	Q_strnlwr( MD5_Print( md5 ), key, size );
 }
 
 void ID_Init( void )
 {
-	MD5Context_t hash = { 0 };
-	byte md5[16];
-	int i;
-
 	Cmd_AddRestrictedCommand( "bloomfilter", ID_BloomFilter_f, "print bloomfilter raw value of arguments set");
 	Cmd_AddRestrictedCommand( "verifyhex", ID_VerifyHEX_f, "check if id source seems to be fake" );
 #if XASH_LINUX
@@ -703,13 +726,6 @@ void ID_Init( void )
 	if( !id )
 		id = ID_GenerateRawId();
 
-	MD5Init( &hash );
-	MD5Update( &hash, (byte *)&id, sizeof( id ) );
-	MD5Final( (byte*)md5, &hash );
-
-	for( i = 0; i < 16; i++ )
-		Q_snprintf( &id_md5[i*2], sizeof( id_md5 ) - i * 2, "%02hhx", md5[i] );
-
 #if XASH_ANDROID && !XASH_DEDICATED
 	Android_SaveID( va("%016"PRIX64, id^SYSTEM_XOR_MASK ) );
 #elif XASH_WIN32