X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/7b242c1ca24fa8c59512f6c6f5f2a543c7ad3342..dc8ba239fbc1b8f50f572e84adfcfdf52bd0d0da:/armsrc/mifarecmd.c

diff --git a/armsrc/mifarecmd.c b/armsrc/mifarecmd.c
index 939c9002..14d2b68a 100644
--- a/armsrc/mifarecmd.c
+++ b/armsrc/mifarecmd.c
@@ -645,6 +645,9 @@ void MifareNested(uint32_t arg0, uint32_t arg1, uint32_t calibrate, uint8_t *dat
 
 
 	// statistics on nonce distance
+	int16_t isOK = 0;
+	#define NESTED_MAX_TRIES 12
+	uint16_t unsuccessfull_tries = 0;
 	if (calibrate) {	// for first call only. Otherwise reuse previous calibration
 		LED_B_ON();
 		WDT_HIT();
@@ -655,6 +658,12 @@ void MifareNested(uint32_t arg0, uint32_t arg1, uint32_t calibrate, uint8_t *dat
 		
 		for (rtr = 0; rtr < 17; rtr++) {
 
+			// Test if the action was cancelled
+			if(BUTTON_PRESS()) {
+				isOK = -2;
+				break;
+			}
+
 			// prepare next select. No need to power down the card.
 			if(mifare_classic_halt(pcs, cuid)) {
 				if (MF_DBGLEVEL >= 1)	Dbprintf("Nested: Halt error");
@@ -702,14 +711,17 @@ void MifareNested(uint32_t arg0, uint32_t arg1, uint32_t calibrate, uint8_t *dat
 					delta_time = auth2_time - auth1_time + 32;  // allow some slack for proper timing
 				}
 				if (MF_DBGLEVEL >= 3) Dbprintf("Nested: calibrating... ntdist=%d", i);
+			} else {
+				unsuccessfull_tries++;
+				if (unsuccessfull_tries > NESTED_MAX_TRIES) {	// card isn't vulnerable to nested attack (random numbers are not predictable)
+					isOK = -3;
+				}
 			}
 		}
-		
-		if (rtr <= 1)	return;
 
 		davg = (davg + (rtr - 1)/2) / (rtr - 1);
 		
-		if (MF_DBGLEVEL >= 3) Dbprintf("min=%d max=%d avg=%d, delta_time=%d", dmin, dmax, davg, delta_time);
+		if (MF_DBGLEVEL >= 3) Dbprintf("rtr=%d isOK=%d min=%d max=%d avg=%d, delta_time=%d", rtr, isOK, dmin, dmax, davg, delta_time);
 
 		dmin = davg - 2;
 		dmax = davg + 2;
@@ -722,7 +734,7 @@ void MifareNested(uint32_t arg0, uint32_t arg1, uint32_t calibrate, uint8_t *dat
 	LED_C_ON();
 
 	//  get crypted nonces for target sector
-	for(i=0; i < 2; i++) { // look for exactly two different nonces
+	for(i=0; i < 2 && !isOK; i++) { // look for exactly two different nonces
 
 		target_nt[i] = 0;
 		while(target_nt[i] == 0) { // continue until we have an unambiguous nonce
@@ -800,7 +812,7 @@ void MifareNested(uint32_t arg0, uint32_t arg1, uint32_t calibrate, uint8_t *dat
 	memcpy(buf+16, &target_ks[1], 4);
 	
 	LED_B_ON();
-	cmd_send(CMD_ACK, 0, 2, targetBlockNo + (targetKeyType * 0x100), buf, sizeof(buf));
+	cmd_send(CMD_ACK, isOK, 0, targetBlockNo + (targetKeyType * 0x100), buf, sizeof(buf));
 	LED_B_OFF();
 
 	if (MF_DBGLEVEL >= 3)	DbpString("NESTED FINISHED");