From 3e4811c8b77f4e3d84ed681f6b49704a18c2b3c4 Mon Sep 17 00:00:00 2001
From: iceman1001 <iceman@iuse.se>
Date: Thu, 12 Mar 2015 23:04:02 +0100
Subject: [PATCH] FIX:  adding a test to see if we managed to get the correct
 demodulation from an unknown t55x7 tag.    By checking if the configuration
 data (page 0, block 0)  has some settings that must be the same.   think 
 reserved 7bits, This is a trail and error approach. But together with setting
 a manual configuration to read a tag and this automatic verification it will
 help out alot I think.

---
 client/cmdlft55xx.c | 52 ++++++++++++++++++++++++++++++++-------------
 client/cmdlft55xx.h |  1 +
 2 files changed, 38 insertions(+), 15 deletions(-)

diff --git a/client/cmdlft55xx.c b/client/cmdlft55xx.c
index 7a377cc9..29b8032e 100644
--- a/client/cmdlft55xx.c
+++ b/client/cmdlft55xx.c
@@ -218,45 +218,67 @@ int CmdReadBlk(const char *Cmd)
 	
 	if (CmdDetectClockRate("f")){ //wave is almost certainly FSK
 	  	// FSK
-		if ( FSKrawDemod("0 0", FALSE))
+		if ( FSKrawDemod("0 0", FALSE) && test())
 			printT55xx("FSK");
 		// FSK inverted
-		if ( FSKrawDemod("0 1", FALSE)) 
+		if ( FSKrawDemod("0 1", FALSE) && test()) 
 			printT55xx("FSK inv");
     } else {
 		// ASK/MAN (autoclock, normal, maxerrors 1)
-		if ( ASKmanDemod("0 0 1", FALSE, FALSE) )
+		if ( ASKmanDemod("0 0 1", FALSE, FALSE) && test()) 
 			printT55xx("ASK/MAN");
 		
 		// ASK/MAN (autoclock, inverted, maxerrors 1)
-		if ( ASKmanDemod("0 1 1", FALSE, FALSE) )
+		if ( ASKmanDemod("0 1 1", FALSE, FALSE)  && test()) 
 			printT55xx("ASK/MAN Inv");
 
 		// NZR (autoclock, normal, maxerrors 1)
-		if  ( NRZrawDemod("0 0 1", FALSE) )
+		if ( NRZrawDemod("0 0 1", FALSE)  && test()) 
 			printT55xx("NZR");
 		// NZR (autoclock, inverted, maxerrors 1)
-		if  ( NRZrawDemod("0 1 1", FALSE) )
+		if ( NRZrawDemod("0 1 1", FALSE)  && test()) 
 			printT55xx("NZR inv");
 		
 		// PSK (autoclock, normal, maxerrors 1)
-		if (!PSKDemod("0 0 1", FALSE))
+		if ( PSKDemod("0 0 1", FALSE)  && test()) 
 			printT55xx("PSK");
 
 		// PSK (autoclock, inverted, maxerrors 1)
-		if (!PSKDemod("0 1 1", FALSE))
+		if ( PSKDemod("0 1 1", FALSE) && test()) 
 			printT55xx("PSK inv");
 		
 		//PSK2?
 		
-		// if (!BiphaseRawDecode("0",FALSE))
+		// if (!BiphaseRawDecode("0",FALSE)  && test()) 
 			// printT55xx("BIPHASE");
 		
-		// if (!BiphaseRawDecode("1",FALSE))
+		// if (!BiphaseRawDecode("1",FALSE) && test()) 
 			// printT55xx("BIPHASE inv");
 	}
 	return 0;
 }
+bool test(){
+
+	if ( !DemodBufferLen) 
+		return false;
+	
+	uint8_t si = 1;
+	uint8_t safer    = PackBits(si, 4, DemodBuffer); si += 4;	
+	uint8_t resv     = PackBits(si, 7, DemodBuffer); si += 7+3;
+	uint8_t extend   = PackBits(si, 1, DemodBuffer); si += 1;
+
+	//PrintAndLog("test: %X %X %X ", safer, resv, extend);
+	
+	// 2nibble must be zeroed.
+	if ( resv > 0x00) return FALSE;
+
+	if ( safer == 0x6 || safer == 0x9){
+		if ( extend == 0x00)
+			return TRUE;
+	}
+	if ( resv== 0x00) return TRUE;
+	return FALSE;
+}
 
 void printT55xx(const char *demodStr){
 	
@@ -434,7 +456,7 @@ int CmdInfo(const char *Cmd){
 	uint32_t resv     = PackBits(si, 7, bits); si += 7;
 	uint32_t dbr      = PackBits(si, 3, bits); si += 3;
 	uint32_t extend   = PackBits(si, 1, bits); si += 1;
-	uint32_t datamodulation   = PackBits(si, 5, bits); si += 5;
+	uint32_t datamod  = PackBits(si, 5, bits); si += 5;
 	uint32_t pskcf    = PackBits(si, 2, bits); si += 2;
 	uint32_t aor      = PackBits(si, 1, bits); si += 1;	
 	uint32_t otp      = PackBits(si, 1, bits); si += 1;	
@@ -452,14 +474,14 @@ int CmdInfo(const char *Cmd){
 	PrintAndLog(" reserved                  : %d", resv);
 	PrintAndLog(" Data bit rate             : %s", GetBitRateStr(dbr));
 	PrintAndLog(" eXtended mode             : %s", (extend) ? "Yes - Warning":"No");
-	PrintAndLog(" Modulation                : %s", GetModulationStr(datamodulation) );
+	PrintAndLog(" Modulation                : %s", GetModulationStr(datamod));
 	PrintAndLog(" PSK clock freq            : %d", pskcf);
 	PrintAndLog(" AOR - Answer on Request   : %s", (aor) ? "Yes":"No");
 	PrintAndLog(" OTP - One Time Pad        : %s", (otp) ? "Yes - Warning":"No" );
 	PrintAndLog(" Max block                 : %d", maxblk);
 	PrintAndLog(" Password mode             : %s", (pwd) ? "Yes":"No");
 	PrintAndLog(" Sequence Start Terminator : %s", (sst) ? "Yes":"No");
-	PrintAndLog(" Fast Write                : %s", (fw) ? "Yes":"No");
+	PrintAndLog(" Fast Write                : %s", (fw)  ? "Yes":"No");
 	PrintAndLog(" Inverse data              : %s", (inv) ? "Yes":"No");
 	PrintAndLog(" POR-Delay                 : %s", (por) ? "Yes":"No");
 	PrintAndLog("-------------------------------------------------------------");
@@ -543,10 +565,10 @@ char * GetSaferStr(uint32_t id){
 	
 	sprintf(retStr,"%d",id);
 	if (id == 6) {
-		sprintf(retStr,"%d - pasdwd",id);
+		sprintf(retStr,"%d - passwd",id);
 	}
 	if (id == 9 ){
-		sprintf(retStr,"%d - testmode ",id);
+		sprintf(retStr,"%d - testmode",id);
 	}
 	
 	return buf;
diff --git a/client/cmdlft55xx.h b/client/cmdlft55xx.h
index 7ae0159b..31ffa499 100644
--- a/client/cmdlft55xx.h
+++ b/client/cmdlft55xx.h
@@ -22,4 +22,5 @@ char * GetSaferStr(uint32_t id);
 char * GetModulationStr( uint32_t id);
 uint32_t PackBits(uint8_t start, uint8_t len, uint8_t* bitstream);
 void printT55xx(const char *demodStr);
+bool test();
 #endif
-- 
2.39.5