X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/cc15a1187b698d185a42fe956c0b68b9384eafdd..8e99ec25edb501c00d1d0a9fc57709ff88f56495:/client/cmdlft55xx.c

diff --git a/client/cmdlft55xx.c b/client/cmdlft55xx.c
index e0f89153..efa6c22d 100644
--- a/client/cmdlft55xx.c
+++ b/client/cmdlft55xx.c
@@ -37,7 +37,7 @@ int usage_t55xx_config(){
 	PrintAndLog("Options:        ");
 	PrintAndLog("       h                        This help");
 	PrintAndLog("       b <8|16|32|40|50|64|100|128>     Set bitrate");
-	PrintAndLog("       d <FSK|FSK1|FSK1a|FSK2|FSK2a|ASK|PSK1|PSK2|NZ|BI|BIa>  Set demodulation FSK / ASK / PSK / NZ / Biphase / Biphase A");
+	PrintAndLog("       d <FSK|FSK1|FSK1a|FSK2|FSK2a|ASK|PSK1|PSK2|NRZ|BI|BIa>  Set demodulation FSK / ASK / PSK / NRZ / Biphase / Biphase A");
 	PrintAndLog("       i [1]                            Invert data signal, defaults to normal");
 	PrintAndLog("       o [offset]                       Set offset, where data should start decode in bitstream");
 	PrintAndLog("");
@@ -49,25 +49,30 @@ int usage_t55xx_config(){
 	return 0;
 }
 int usage_t55xx_read(){
-	PrintAndLog("Usage:  lf t55xx read <block> <password>");
-    PrintAndLog("     <block>, block number to read. Between 0-7");
-    PrintAndLog("     <password>, OPTIONAL password (8 hex characters)");
-    PrintAndLog("");
+	PrintAndLog("Usage:  lf t55xx read <block> <password> <override_safety>");
+	PrintAndLog("     <block>, block number to read. Between 0-7");
+	PrintAndLog("     <password>, OPTIONAL password (8 hex characters)");
+	PrintAndLog("     <override_safety>, OPTIONAL override safety check = 1");
+	PrintAndLog("     ****WARNING****");
+	PrintAndLog("     Use of read with password on a tag not configured for a pwd");
+	PrintAndLog("     can damage the tag");
+	PrintAndLog("");
 	PrintAndLog("Examples:");
-    PrintAndLog("      lf t55xx read 0           - read data from block 0");
-	PrintAndLog("      lf t55xx read 0 feedbeef  - read data from block 0 password feedbeef");
+	PrintAndLog("      lf t55xx read 0            - read data from block 0");
+	PrintAndLog("      lf t55xx read 0 feedbeef   - read data from block 0 password feedbeef");
+	PrintAndLog("      lf t55xx read 0 feedbeef 1 - read data from block 0 password feedbeef safety check");
 	PrintAndLog("");
 	return 0;
 }
 int usage_t55xx_write(){
 	PrintAndLog("Usage:  lf t55xx wr <block> <data> [password]");
-    PrintAndLog("     <block>, block number to read. Between 0-7");
+	PrintAndLog("     <block>, block number to write. Between 0-7");
 	PrintAndLog("     <data>,  4 bytes of data to write (8 hex characters)");
-    PrintAndLog("     [password], OPTIONAL password 4bytes (8 hex characters)");
-    PrintAndLog("");
+	PrintAndLog("     [password], OPTIONAL password 4bytes (8 hex characters)");
+	PrintAndLog("");
 	PrintAndLog("Examples:");
-    PrintAndLog("      lf t55xx wd 3 11223344           - write 11223344 to block 3");
-	PrintAndLog("      lf t55xx wd 3 11223344 feedbeef  - write 11223344 to block 3 password feedbeef");
+	PrintAndLog("      lf t55xx wr 3 11223344           - write 11223344 to block 3");
+	PrintAndLog("      lf t55xx wr 3 11223344 feedbeef  - write 11223344 to block 3 password feedbeef");
 	PrintAndLog("");
 	return 0;
 }
@@ -116,12 +121,12 @@ static int CmdHelp(const char *Cmd);
 int CmdT55xxSetConfig(const char *Cmd) {
 
 	uint8_t offset = 0;
-	bool errors = FALSE;
-	uint8_t cmdp = 0;
 	char modulation[5] = {0x00};
 	char tmp = 0x00;
 	uint8_t bitRate = 0;
 	uint8_t rates[9] = {8,16,32,40,50,64,100,128,0};
+	uint8_t cmdp = 0;
+	bool errors = FALSE;
 	while(param_getchar(Cmd, cmdp) != 0x00 && !errors)
 	{
 		tmp = param_getchar(Cmd, cmdp);
@@ -215,33 +220,76 @@ int CmdT55xxSetConfig(const char *Cmd) {
 }
 
 int CmdT55xxReadBlock(const char *Cmd) {
-	int block = -1;
-	int password = 0xFFFFFFFF; //default to blank Block 7
-
-	char cmdp = param_getchar(Cmd, 0);
-	if (cmdp == 'h' || cmdp == 'H')
-		return usage_t55xx_read();
-
-	int res = sscanf(Cmd, "%d %x", &block, &password);
-
-	if ( res < 1 || res > 2 )
-		return usage_t55xx_read();
-
-	
-	if ((block < 0) | (block > 7)) {
+	uint8_t block = 255;
+	uint8_t wake = 0;
+	uint8_t usepwd = 0;
+	uint32_t password = 0xFFFFFFFF; //default to blank Block 7
+	uint8_t override = 0;
+	uint8_t cmdp = 0;
+	bool errors = false;
+	while(param_getchar(Cmd, cmdp) != 0x00 && !errors) {
+		switch(param_getchar(Cmd, cmdp)) {
+		case 'h':
+		case 'H':
+			return usage_t55xx_read();
+		case 'b':
+		case 'B':
+			errors |= param_getdec(Cmd, cmdp+1, &block);
+			cmdp+=2;
+			break;
+		case 'o':
+		case 'O':
+			override = 1;
+			cmdp++;
+			break;
+		case 'p':
+		case 'P':
+			password = param_get32ex(Cmd, cmdp+1, 0, 10);
+			usepwd = 1;
+			cmdp+=2;
+			break;
+		case 'w':
+		case 'W':
+			wake = 1;
+			cmdp++;
+			break;
+		default:
+			PrintAndLog("Unknown parameter '%c'", param_getchar(Cmd, cmdp));
+			errors = true;
+			break;
+		}
+	}
+	if (errors) return usage_t55xx_read();
+	if (wake && !usepwd) {
+		PrintAndLog("Wake command must use a pwd");
+		return 1;
+	}
+	if ((block > 7) && !wake) {
 		PrintAndLog("Block must be between 0 and 7");
 		return 1;
-	}	
+	}
 
-	UsbCommand c = {CMD_T55XX_READ_BLOCK, {0, block, 0}};
- 	c.d.asBytes[0] = 0x0; 
+	UsbCommand c = {CMD_T55XX_READ_BLOCK, {0, block, password}};
 
 	//Password mode
-	if ( res == 2 ) {
-		c.arg[2] = password;
-		c.d.asBytes[0] = 0x1; 
+	if ( usepwd || wake ) {
+		// try reading the config block and verify that PWD bit is set before doing this!
+		if ( wake || override ) {
+			c.arg[0] = (wake<<8) & usepwd;
+			if ( !wake && override )
+				PrintAndLog("Safety Check Overriden - proceeding despite risk");
+		} else {
+			AquireData( CONFIGURATION_BLOCK );
+			if ( !tryDetectModulation() ) {
+				PrintAndLog("Safety Check: Could not detect if PWD bit is set in config block. Exits.");
+				return 1;
+			} else {
+				PrintAndLog("Safety Check: PWD bit is NOT set in config block. Reading without password...");	
+			}
+		}
 	}
 
+	clearCommandBuffer();
 	SendCommand(&c);
 	if ( !WaitForResponseTimeout(CMD_ACK,NULL,2500) ) {
 		PrintAndLog("command execution time out");
@@ -249,30 +297,32 @@ int CmdT55xxReadBlock(const char *Cmd) {
 	}
 	
 	uint8_t got[12000];
-	GetFromBigBuf(got,sizeof(got),0);
+	GetFromBigBuf(got, sizeof(got), 0);
 	WaitForResponse(CMD_ACK,NULL);
-	setGraphBuf(got, 12000);
-	DemodBufferLen=0;
+	setGraphBuf(got, sizeof(got));
+	//DemodBufferLen=0;
 	if (!DecodeT55xxBlock()) return 3;
 	char blk[10]={0};
-	sprintf(blk,"%d", block);
+	if ( wake ) {
+		sprintf(blk,"wake");
+	} else {
+		sprintf(blk,"%d", block);
+	}
 	printT55xxBlock(blk);
 	return 0;
 }
 
 bool DecodeT55xxBlock(){
 	
-	char buf[10] = {0x00};
+	char buf[30] = {0x00};
 	char *cmdStr = buf;
 	int ans = 0;
 	uint8_t bitRate[8] = {8,16,32,40,50,64,100,128};
-
 	DemodBufferLen = 0x00;
 
 	//trim 1/2 a clock from beginning
-	snprintf(cmdStr, sizeof(buf),"%d", bitRate[config.bitrate]/2 );
-	CmdLtrim(cmdStr);
-
+	//snprintf(cmdStr, sizeof(buf),"%d", bitRate[config.bitrate]/2 );
+	//CmdLtrim(cmdStr);
 	switch( config.modulation ){
 		case DEMOD_FSK:
 			snprintf(cmdStr, sizeof(buf),"%d %d", bitRate[config.bitrate], config.inverted );
@@ -290,7 +340,7 @@ bool DecodeT55xxBlock(){
 			break;
 		case DEMOD_ASK:
 			snprintf(cmdStr, sizeof(buf),"%d %d 0", bitRate[config.bitrate], config.inverted );
-			ans = ASKmanDemod(cmdStr, FALSE, FALSE);
+			ans = ASKDemod(cmdStr, FALSE, FALSE, 1);
 			break;
 		case DEMOD_PSK1:
 			snprintf(cmdStr, sizeof(buf),"%d %d 0", bitRate[config.bitrate], config.inverted );
@@ -334,117 +384,144 @@ int CmdT55xxDetect(const char *Cmd){
 
 // detect configuration?
 bool tryDetectModulation(){
-	char cmdStr[8] = {0};
+	//char cmdStr[8] = {0};
 	uint8_t hits = 0;
 	t55xx_conf_block_t tests[15];
-	
+	int bitRate=0;
+	uint8_t fc1 = 0, fc2 = 0, clk=0;
+	save_restoreGB(1);
 	if (GetFskClock("", FALSE, FALSE)){ 
-		uint8_t fc1 = 0, fc2 = 0, clk=0;
 		fskClocks(&fc1, &fc2, &clk, FALSE);
-		sprintf(cmdStr,"%d", clk/2);
-		CmdLtrim(cmdStr);
-		if ( FSKrawDemod("0 0", FALSE) && test(DEMOD_FSK, &tests[hits].offset)){
+		//sprintf(cmdStr,"%d", clk/2);
+		//CmdLtrim(cmdStr);
+		if ( FSKrawDemod("0 0", FALSE) && test(DEMOD_FSK, &tests[hits].offset, &bitRate)){
 			tests[hits].modulation = DEMOD_FSK;
 			if (fc1==8 && fc2 == 5)
 				tests[hits].modulation = DEMOD_FSK1a;
 			else if (fc1==10 && fc2 == 8)
 				tests[hits].modulation = DEMOD_FSK2;
-
+			tests[hits].bitrate = bitRate;
 			tests[hits].inverted = FALSE;
 			tests[hits].block0 = PackBits(tests[hits].offset, 32, DemodBuffer);
 			++hits;
 		}
-		if ( FSKrawDemod("0 1", FALSE) && test(DEMOD_FSK, &tests[hits].offset)) {
+		if ( FSKrawDemod("0 1", FALSE) && test(DEMOD_FSK, &tests[hits].offset, &bitRate)) {
 			tests[hits].modulation = DEMOD_FSK;
-			if (fc1==8 && fc2 == 5)
+			if (fc1 == 8 && fc2 == 5)
 				tests[hits].modulation = DEMOD_FSK1;
-			else if (fc1==10 && fc2 == 8)
+			else if (fc1 == 10 && fc2 == 8)
 				tests[hits].modulation = DEMOD_FSK2a;
 
+			tests[hits].bitrate = bitRate;
 			tests[hits].inverted = TRUE;
 			tests[hits].block0 = PackBits(tests[hits].offset, 32, DemodBuffer);
 			++hits;
 		}
 	} else {
-		if ( ASKmanDemod("0 0 1", FALSE, FALSE) && test(DEMOD_ASK, &tests[hits].offset)) {
-			tests[hits].modulation = DEMOD_ASK;
-			tests[hits].inverted = FALSE;
-			tests[hits].block0 = PackBits(tests[hits].offset, 32, DemodBuffer);
-			++hits;
+		clk = GetAskClock("", FALSE, FALSE);
+		if (clk>0) {
+			//sprintf(cmdStr,"%d", clk/2);
+			//CmdLtrim(cmdStr);
+			if ( ASKDemod("0 0 0", FALSE, FALSE, 1) && test(DEMOD_ASK, &tests[hits].offset, &bitRate)) {
+				tests[hits].modulation = DEMOD_ASK;
+				tests[hits].bitrate = bitRate;
+				tests[hits].inverted = FALSE;
+				tests[hits].block0 = PackBits(tests[hits].offset, 32, DemodBuffer);
+				++hits;
 			}
-
-		if ( ASKmanDemod("0 1 1", FALSE, FALSE)  && test(DEMOD_ASK, &tests[hits].offset)) {
-			tests[hits].modulation = DEMOD_ASK;
-			tests[hits].inverted = TRUE;
-			tests[hits].block0 = PackBits(tests[hits].offset, 32, DemodBuffer);
-			++hits;
+			if ( ASKDemod("0 1 0", FALSE, FALSE, 1)  && test(DEMOD_ASK, &tests[hits].offset, &bitRate)) {
+				tests[hits].modulation = DEMOD_ASK;
+				tests[hits].bitrate = bitRate;
+				tests[hits].inverted = TRUE;
+				tests[hits].block0 = PackBits(tests[hits].offset, 32, DemodBuffer);
+				++hits;
+			}
+			if ( ASKbiphaseDemod("0 0 0 0", FALSE) && test(DEMOD_BI, &tests[hits].offset, &bitRate) ) {
+				tests[hits].modulation = DEMOD_BI;
+				tests[hits].bitrate = bitRate;
+				tests[hits].inverted = FALSE;
+				tests[hits].block0 = PackBits(tests[hits].offset, 32, DemodBuffer);
+				++hits;
+			}
+			if ( ASKbiphaseDemod("0 0 1 0", FALSE) && test(DEMOD_BIa, &tests[hits].offset, &bitRate) ) {
+				tests[hits].modulation = DEMOD_BIa;
+				tests[hits].bitrate = bitRate;
+				tests[hits].inverted = TRUE;
+				tests[hits].block0 = PackBits(tests[hits].offset, 32, DemodBuffer);
+				++hits;
 			}
-		
-		if ( NRZrawDemod("0 0 1", FALSE)  && test(DEMOD_NRZ, &tests[hits].offset)) {
-			tests[hits].modulation = DEMOD_NRZ;
-			tests[hits].inverted = FALSE;
-			tests[hits].block0 = PackBits(tests[hits].offset, 32, DemodBuffer);
-			++hits;
 		}
+		//undo trim from ask
+		save_restoreGB(0);
+		clk = GetNrzClock("", FALSE, FALSE);
+		if (clk>0) {
+			//sprintf(cmdStr,"%d", clk/2);
+			//CmdLtrim(cmdStr);
+			if ( NRZrawDemod("0 0 1", FALSE)  && test(DEMOD_NRZ, &tests[hits].offset, &bitRate)) {
+				tests[hits].modulation = DEMOD_NRZ;
+				tests[hits].bitrate = bitRate;
+				tests[hits].inverted = FALSE;
+				tests[hits].block0 = PackBits(tests[hits].offset, 32, DemodBuffer);
+				++hits;
+			}
 
-		if ( NRZrawDemod("0 1 1", FALSE)  && test(DEMOD_NRZ, &tests[hits].offset)) {
-			tests[hits].modulation = DEMOD_NRZ;
-			tests[hits].inverted = TRUE;
-			tests[hits].block0 = PackBits(tests[hits].offset, 32, DemodBuffer);
-			++hits;
+			if ( NRZrawDemod("0 1 1", FALSE)  && test(DEMOD_NRZ, &tests[hits].offset, &bitRate)) {
+				tests[hits].modulation = DEMOD_NRZ;
+				tests[hits].bitrate = bitRate;
+				tests[hits].inverted = TRUE;
+				tests[hits].block0 = PackBits(tests[hits].offset, 32, DemodBuffer);
+				++hits;
 			}
-		
-		if ( PSKDemod("0 0 1", FALSE) && test(DEMOD_PSK1, &tests[hits].offset)) {
-			tests[hits].modulation = DEMOD_PSK1;
-			tests[hits].inverted = FALSE;
-			tests[hits].block0 = PackBits(tests[hits].offset, 32, DemodBuffer);
-			++hits;
 		}
 		
-		if ( PSKDemod("0 1 1", FALSE) && test(DEMOD_PSK1, &tests[hits].offset)) {
-			tests[hits].modulation = DEMOD_PSK1;
-			tests[hits].inverted = TRUE;
-			tests[hits].block0 = PackBits(tests[hits].offset, 32, DemodBuffer);
-			++hits;
-		}
-
-		// PSK2 - needs a call to psk1TOpsk2.
-		if ( PSKDemod("0 0 1", FALSE)) {
-			psk1TOpsk2(DemodBuffer, DemodBufferLen);
-			if (test(DEMOD_PSK2, &tests[hits].offset)){
-				tests[hits].modulation = DEMOD_PSK2;
+		//undo trim from nrz
+		save_restoreGB(0);
+		clk = GetPskClock("", FALSE, FALSE);
+		if (clk>0) {
+			//PrintAndLog("clk %d",clk);
+			//sprintf(cmdStr,"%d", clk/2);
+			//CmdLtrim(cmdStr);	
+			if ( PSKDemod("0 0 1", FALSE) && test(DEMOD_PSK1, &tests[hits].offset, &bitRate)) {
+				tests[hits].modulation = DEMOD_PSK1;
+				tests[hits].bitrate = bitRate;
 				tests[hits].inverted = FALSE;
 				tests[hits].block0 = PackBits(tests[hits].offset, 32, DemodBuffer);
 				++hits;
 			}
-		} // inverse waves does not affect this demod
-
-		// PSK3 - needs a call to psk1TOpsk2.
-		if ( PSKDemod("0 0 1", FALSE)) {
-			psk1TOpsk2(DemodBuffer, DemodBufferLen);
-			if (test(DEMOD_PSK3, &tests[hits].offset)){
-				tests[hits].modulation = DEMOD_PSK3;
-				tests[hits].inverted = FALSE;
+			if ( PSKDemod("0 1 1", FALSE) && test(DEMOD_PSK1, &tests[hits].offset, &bitRate)) {
+				tests[hits].modulation = DEMOD_PSK1;
+				tests[hits].bitrate = bitRate;
+				tests[hits].inverted = TRUE;
 				tests[hits].block0 = PackBits(tests[hits].offset, 32, DemodBuffer);
 				++hits;
 			}
-		} // inverse waves does not affect this demod
-	
-		if ( ASKbiphaseDemod("0 0 0 1", FALSE) && test(DEMOD_BI, &tests[hits].offset) ) {
-			tests[hits].modulation = DEMOD_BI;
-			tests[hits].inverted = FALSE;
-			tests[hits].block0 = PackBits(tests[hits].offset, 32, DemodBuffer);
-			++hits;
-		}
-		if ( ASKbiphaseDemod("0 0 1 1", FALSE) && test(DEMOD_BIa, &tests[hits].offset) ) {
-			tests[hits].modulation = DEMOD_BIa;
-			tests[hits].inverted = TRUE;
-			tests[hits].block0 = PackBits(tests[hits].offset, 32, DemodBuffer);
-			++hits;
+			// PSK2 - needs a call to psk1TOpsk2.
+			if ( PSKDemod("0 0 1", FALSE)) {
+				psk1TOpsk2(DemodBuffer, DemodBufferLen);
+				if (test(DEMOD_PSK2, &tests[hits].offset, &bitRate)){
+					tests[hits].modulation = DEMOD_PSK2;
+					tests[hits].bitrate = bitRate;
+					tests[hits].inverted = FALSE;
+					tests[hits].block0 = PackBits(tests[hits].offset, 32, DemodBuffer);
+					++hits;
+				}
+			} // inverse waves does not affect this demod
+			// PSK3 - needs a call to psk1TOpsk2.
+			if ( PSKDemod("0 0 1", FALSE)) {
+				psk1TOpsk2(DemodBuffer, DemodBufferLen);
+				if (test(DEMOD_PSK3, &tests[hits].offset, &bitRate)){
+					tests[hits].modulation = DEMOD_PSK3;
+					tests[hits].bitrate = bitRate;
+					tests[hits].inverted = FALSE;
+					tests[hits].block0 = PackBits(tests[hits].offset, 32, DemodBuffer);
+					++hits;
+				}
+			} // inverse waves does not affect this demod
 		}
 	}		
 	if ( hits == 1) {
 		config.modulation = tests[0].modulation;
+		config.bitrate = tests[0].bitrate;
 		config.inverted = tests[0].inverted;
 		config.offset = tests[0].offset;
 		config.block0 = tests[0].block0;
@@ -504,35 +581,27 @@ bool testBitRate(uint8_t readRate, uint8_t mod){
 		case DEMOD_FSK2:
 		case DEMOD_FSK2a:
 			detRate = GetFskClock("",FALSE, FALSE); 
-			if (expected[readRate] == detRate) {
-				config.bitrate = readRate;
+			if (expected[readRate] == detRate) 
 				return TRUE;
-			}
 			break;
 		case DEMOD_ASK:
 		case DEMOD_BI:
 		case DEMOD_BIa:
 			detRate = GetAskClock("",FALSE, FALSE); 
-			if (expected[readRate] == detRate) {
-				config.bitrate = readRate;
+			if (expected[readRate] == detRate) 
 				return TRUE;
-			}
 			break;
 		case DEMOD_PSK1:
 		case DEMOD_PSK2:
 		case DEMOD_PSK3:
 			detRate = GetPskClock("",FALSE, FALSE); 
-			if (expected[readRate] == detRate) {
-				config.bitrate = readRate;
+			if (expected[readRate] == detRate)
 				return TRUE;
-			}
 			break;
 		case DEMOD_NRZ:
 			detRate = GetNrzClock("",FALSE, FALSE); 
-			if (expected[readRate] == detRate) {
-				config.bitrate = readRate;
+			if (expected[readRate] == detRate)
 				return TRUE;
-			}
 			break;
 		default:
 			return FALSE;
@@ -540,9 +609,9 @@ bool testBitRate(uint8_t readRate, uint8_t mod){
 	return FALSE;
 }
 
-bool test(uint8_t mode, uint8_t *offset){
+bool test(uint8_t mode, uint8_t *offset, int *fndBitRate){
 
-	if ( !DemodBufferLen) return FALSE;
+	if ( DemodBufferLen < 64 ) return FALSE;
 	uint8_t si = 0;
 	for (uint8_t idx = 0; idx < 64; idx++){
 		si = idx;
@@ -555,7 +624,8 @@ bool test(uint8_t mode, uint8_t *offset){
 		if ( resv > 0x00) continue;
 
 		uint8_t xtRate   = PackBits(si, 3, DemodBuffer); si += 3;     //extended mode part of rate
-		uint8_t bitRate  = PackBits(si, 3, DemodBuffer); si += 3;     //bit rate
+		int bitRate  = PackBits(si, 3, DemodBuffer); si += 3;     //bit rate
+		if (bitRate > 7) continue;
 		uint8_t extend   = PackBits(si, 1, DemodBuffer); si += 1;     //bit 15 extended mode
 		uint8_t modread  = PackBits(si, 5, DemodBuffer); si += 5+2+1; 
 		//uint8_t pskcr   = PackBits(si, 2, DemodBuffer); si += 2+1;  //could check psk cr
@@ -571,6 +641,7 @@ bool test(uint8_t mode, uint8_t *offset){
 		//test modulation
 		if (!testModulation(mode, modread)) continue;
 		if (!testBitRate(bitRate, mode)) continue;
+		*fndBitRate = bitRate;
 		*offset = idx;
 		return TRUE;
 	}
@@ -651,6 +722,7 @@ int CmdT55xxWriteBlock(const char *Cmd)
 	}
 	
 	UsbCommand c = {CMD_T55XX_WRITE_BLOCK, {data, block, 0}};
+	UsbCommand resp;
  	c.d.asBytes[0] = 0x0; 
 
 	PrintAndLog("Writing to block: %d  data  : 0x%08X", block, data);
@@ -661,7 +733,12 @@ int CmdT55xxWriteBlock(const char *Cmd)
 		c.d.asBytes[0] = 0x1; 
 		PrintAndLog("pwd   : 0x%08X", password);
 	}
+	clearCommandBuffer();
 	SendCommand(&c);
+	if (!WaitForResponseTimeout(CMD_ACK, &resp, 1000)){
+		PrintAndLog("Error occurred, device did not ACK write operation. (May be due to old firmware)");
+		return -1;
+	}
 	return 0;
 }
 
@@ -760,10 +837,10 @@ int CmdT55xxInfo(const char *Cmd){
 	
 	if (strlen(Cmd)==0)
 		AquireData( CONFIGURATION_BLOCK );
-	
+
 	if (!DecodeT55xxBlock()) return 1;
 
-	if ( !DemodBufferLen) return 1;
+	if ( DemodBufferLen < 32) return 1;
 
 	uint8_t si = config.offset;
 	uint32_t bl0      = PackBits(si, 32, DemodBuffer);
@@ -859,6 +936,7 @@ int AquireData( uint8_t block ){
 		// c.d.asBytes[0] = 0x1; 
 	// }
 
+	clearCommandBuffer();
 	SendCommand(&c);
 	if ( !WaitForResponseTimeout(CMD_ACK,NULL,2500) ) {
 		PrintAndLog("command execution time out");
@@ -873,7 +951,8 @@ int AquireData( uint8_t block ){
 }
 
 char * GetBitRateStr(uint32_t id){
- 	static char buf[20];
+ 	static char buf[25];
+
 	char *retStr = buf;
 		switch (id){
 		case 0: