Added rcon password hashing to prevent them from being sent as plain-text.

Commands+results are still plain-text so ideally use dtls/tls/wss/ssh/https for rcon instead, but this should be compatible with ezquake+mvdsv.


git-svn-id: https://svn.code.sf.net/p/fteqw/code/trunk@5295 fc73d0e0-1445-4013-8a0c-d673dee63da5

engine/client/cl_main.c

@@ -46,6 +46,7 @@ int startuppending;
 void Host_FinishLoading(void);
 
 
+cvar_t	cl_crypt_rcon = CVARFD("cl_crypt_rcon", "1", CVAR_ARCHIVE, "Controls whether to send a hash instead of sending rcon passwords as plain-text. Set to 1 for security, or 0 for backwards compatibility.\nYour command and any responses will still be sent as plain text.\nInstead, it is recommended to use rcon ONLY via dtls/tls/wss connections.");
 cvar_t	rcon_password = CVARF("rcon_password", "", CVAR_NOUNSAFEEXPAND);
 
 cvar_t	rcon_address = CVARF("rcon_address", "", CVAR_NOUNSAFEEXPAND);
@@ -147,6 +148,9 @@ cvar_t	noaim		= CVARF("noaim",		"",			CVAR_ARCHIVE | CVAR_USERINFO);
 cvar_t	msg			= CVARFD("msg",			"1",		CVAR_ARCHIVE | CVAR_USERINFO, "Filter console prints/messages. Only functions on QuakeWorld servers. 0=pickup messages. 1=death messages. 2=critical messages. 3=chat.");
 cvar_t	b_switch	= CVARF("b_switch",		"",			CVAR_ARCHIVE | CVAR_USERINFO);
 cvar_t	w_switch	= CVARF("w_switch",		"",			CVAR_ARCHIVE | CVAR_USERINFO);
+#ifdef HEXEN2
+cvar_t	cl_playerclass=CVARF("cl_playerclass","",		CVAR_ARCHIVE | CVAR_USERINFO);
+#endif
 cvar_t	cl_nofake	= CVARD("cl_nofake",		"2", "value 0: permits \\r chars in chat messages\nvalue 1: blocks all \\r chars\nvalue 2: allows \\r chars, but only from teammates");
 cvar_t	cl_chatsound	= CVAR("cl_chatsound","1");
 cvar_t	cl_enemychatsound	= CVAR("cl_enemychatsound", "misc/talk.wav");
@@ -1437,7 +1441,49 @@ void CL_Rcon_f (void)
 	message[4] = 0;
 
 	Q_strncatz (message, "rcon ", sizeof(message));
-	Q_strncatz (message, password, sizeof(message));
+	if (cl_crypt_rcon.ival)
+	{
+		char	cryptpass[1024], crypttime[64];
+		const char *hex = "0123456789ABCDEF";	//must be upper-case for compat with mvdsv.
+		time_t clienttime;
+		time(&clienttime);
+		size_t digestsize;
+		unsigned char digest[64];
+		const unsigned char **tokens = alloca(sizeof(*tokens)*(4+Cmd_Argc()*2));
+		size_t *tokensizes = alloca(sizeof(*tokensizes)*(4+Cmd_Argc()*2));
+		int j, k;
+
+		for (j = 0; j < sizeof(time_t); j++)
+		{	//little-endian byte order, but big-endian nibble order. just screwed. for compat with ezquake.
+			crypttime[j*2+0] = hex[(clienttime>>(j*8+4))&0xf];
+			crypttime[j*2+1] = hex[(clienttime>>(j*8))&0xf];
+		}
+		crypttime[j*2] = 0;
+
+		tokens[0] = "rcon ";
+		tokens[1] = password;
+		tokens[2] = crypttime;
+		tokens[3] = " ";
+		for (j=0 ; j<Cmd_Argc()-i ; j++)
+		{
+			tokens[4+j*2+0] = Cmd_Argv(i+j);
+			tokens[4+j*2+1] = " ";
+		}
+		for (k = 0; k < 4+j*2; k++)
+			tokensizes[k] = strlen(tokens[k]);
+		digestsize = SHA1_m(digest, sizeof(digest), k, tokens, tokensizes);
+
+		for (j = 0; j < digestsize; j++)
+		{
+			cryptpass[j*2+0] = hex[digest[j]>>4];
+			cryptpass[j*2+1] = hex[digest[j]&0xf];
+		}
+		cryptpass[j*2] = 0;
+		Q_strncatz (message, cryptpass, sizeof(message));
+		Q_strncatz (message, crypttime, sizeof(message));
+	}
+	else
+		Q_strncatz (message, password, sizeof(message));
 	Q_strncatz (message, " ", sizeof(message));
 
 	for ( ; i<Cmd_Argc() ; i++)
@@ -4242,6 +4288,7 @@ void CL_Init (void)
 	Cvar_Register (&m_forward, cl_inputgroup);
 	Cvar_Register (&m_side, cl_inputgroup);
 
+	Cvar_Register (&cl_crypt_rcon,	cl_controlgroup);
 	Cvar_Register (&rcon_password,	cl_controlgroup);
 	Cvar_Register (&rcon_address,	cl_controlgroup);
 
@@ -4309,6 +4356,9 @@ void CL_Init (void)
 	Cvar_Register (&noaim,						cl_controlgroup);
 	Cvar_Register (&b_switch,					cl_controlgroup);
 	Cvar_Register (&w_switch,					cl_controlgroup);
+#ifdef HEXEN2
+	Cvar_Register (&cl_playerclass,				cl_controlgroup);
+#endif
 
 	Cvar_Register (&cl_demoreel,				cl_controlgroup);
 	Cvar_Register (&record_flush,					cl_controlgroup);

engine/server/sv_main.c

@@ -60,7 +60,9 @@ cvar_t	fraglog_details				= CVARD("fraglog_details", "1", "Bitmask\n1: killer+ki
 
 cvar_t	timeout						= CVAR("timeout","65");		// seconds without any message
 cvar_t	zombietime					= CVAR("zombietime", "2");	// seconds to sink messages
-											// after disconnect
+
+cvar_t	sv_crypt_rcon				= CVARFD("sv_crypt_rcon", "", CVAR_ARCHIVE, "Controls whether the rcon password must be hashed or not. Hashed passwords also partially prevent replay attacks, but does NOT prevent malicious actors from reading the commands/results.\n0: completely insecure. ONLY allows plain-text passwords. Do not use.\n1: Mandatory hashing (recommended).\nEmpty: Allow either, whether the password is secure or not is purely the client's responsibility/fault. Only use this for comptibility with old clients.");
+cvar_t	sv_crypt_rcon_clockskew		= CVARFD("sv_timestamplen", "60", CVAR_ARCHIVE, "Limits clock skew to reduce (delayed) replay attacks");
 #ifdef SERVERONLY
 cvar_t	developer					= CVAR("developer","0");		// show extra messages
 
@@ -3328,16 +3330,83 @@ client_t *SVC_DirectConnect(void)
 	return newcl;
 }
 
-
+static int dehex(int i)
+{
+	if      (i >= '0' && i <= '9')
+		return (i-'0');
+	else if (i >= 'A' && i <= 'F')
+		return (i-'A'+10);
+	else
+		return (i-'a'+10);
+}
 int Rcon_Validate (void)
 {
-	if (!strlen (rcon_password.string))
+	const char *realpass = rcon_password.string;
+	const char *pass = Cmd_Argv(1);
+	if (!strlen (realpass))
 		return 0;
 
-	if (strcmp (Cmd_Argv(1), rcon_password.string) )
+	if (!sv_crypt_rcon.ival)
-		return 0;
+	{	//vanilla-compatible
+		if (!strcmp (pass, realpass) )
+			return 1;
+	}
+	if (sv_crypt_rcon.ival || !*sv_crypt_rcon.string)
+	{	//ezquake-compatible
+		//the password arg is "[SHA1Digest][unixtime-in-hex]" where the digest is "[arg0] password[unixtime] arg0 arg1 argn "
+		time_t clienttime = 0;
+		time_t servertime = 0;
+		intptr_t timediff;
+		qbyte b;
 
-	return 1;
+		const size_t digestsize = 20;
+		size_t i, k;
+		unsigned char digest[digestsize];
+		const unsigned char **tokens = alloca(sizeof(*tokens)*(Cmd_Argc()*2+5));	//overallocation in case argc is 0.
+		size_t *toksizes = alloca(sizeof(*toksizes)*(Cmd_Argc()*2+5));	//overallocation in case argc is 0.
+		if (strlen(pass) > digestsize*2)
+		{
+			for (i = 0; pass[digestsize*2+i] && i < sizeof(time_t)*2; i++)
+			{	//mixed endian for compat with ezquake
+				if (!(i & 1))
+					clienttime |= dehex(pass[digestsize*2+i]) << (((i/2)*8)+4);
+				else
+					clienttime |= dehex(pass[digestsize*2+i]) << (((i/2)*8)+0);
+			}
+			time(&servertime);
+			timediff = servertime-clienttime;
+			//make sure the client's time is within our allowed bounds, to prevent (extreme) replay attacks.
+			if (!sv_crypt_rcon_clockskew.value || (timediff >= -sv_crypt_rcon_clockskew.ival && timediff <= sv_crypt_rcon_clockskew.ival))
+			{
+				tokens[0] = Cmd_Argv(0);
+				tokens[1] = " ";
+				tokens[2] = realpass;
+				tokens[3] = pass+digestsize*2;
+				tokens[4] = " ";
+				for (i = 0; i < Cmd_Argc()-2; i++)
+				{
+					tokens[5+i*2+0] = Cmd_Argv(i+2);
+					tokens[5+i*2+1] = " ";	//a trailing space is required.
+				}
+				for (k = 0; k < 5+i*2; k++)
+					toksizes[k] = strlen(tokens[k]);
+				if (digestsize > 0 && digestsize == SHA1_m(digest, sizeof(digest), k, tokens, toksizes))
+				{
+					for (i = 0;;i++)
+					{
+						if (i == digestsize)
+							return 1;
+						if (!pass[i*2+0] || !pass[i*2+1])
+							break;	//premature termination
+						b = dehex(pass[i*2+0])*16+dehex(pass[i*2+1]);
+						if (b != digest[i])
+							break;
+					}
+				}
+			}
+		}
+	}
+	return 0;
 }
 
 /*
@@ -5077,6 +5146,7 @@ void SV_InitLocal (void)
 		Log_Init();
 	}
 	rcon_password.restriction = RESTRICT_MAX;	//no cheatie rconers changing rcon passwords...
+	Cvar_Register (&sv_crypt_rcon,	cvargroup_servercontrol);
 	Cvar_Register (&spectator_password,	cvargroup_servercontrol);
 
 	Cvar_Register (&sv_mintic,	cvargroup_servercontrol);