X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/28fdb04fd8d62e46c36f959b373d662f1a146448..0d2624a0cc13dbe34392da1f8495af6c64a84ddb:/client/mifarehost.c

diff --git a/client/mifarehost.c b/client/mifarehost.c
index 14674b16..9be04b4d 100644
--- a/client/mifarehost.c
+++ b/client/mifarehost.c
@@ -8,189 +8,424 @@
 // mifare commands
 //-----------------------------------------------------------------------------
 
-#include <stdio.h>
-#include <stdlib.h> 
-#include <string.h>
 #include "mifarehost.h"
-#include "proxmark3.h"
 
-// MIFARE
-int compar_int(const void * a, const void * b) {
-	return (*(uint64_t*)b - *(uint64_t*)a);
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <pthread.h>
+
+#include "crapto1/crapto1.h"
+#include "comms.h"
+#include "usb_cmd.h"
+#include "cmdmain.h"
+#include "ui.h"
+#include "parity.h"
+#include "util.h"
+#include "iso14443crc.h"
+
+#include "mifare.h"
+
+// mifare tracer flags used in mfTraceDecode()
+#define TRACE_IDLE		 				0x00
+#define TRACE_AUTH1		 				0x01
+#define TRACE_AUTH2		 				0x02
+#define TRACE_AUTH_OK	 				0x03
+#define TRACE_READ_DATA 				0x04
+#define TRACE_WRITE_OK					0x05
+#define TRACE_WRITE_DATA				0x06
+#define TRACE_ERROR		 				0xFF
+
+
+static int compare_uint64(const void *a, const void *b) {
+	// didn't work: (the result is truncated to 32 bits)
+	//return (*(int64_t*)b - *(int64_t*)a);
+
+	// better:
+	if (*(uint64_t*)b == *(uint64_t*)a) return 0;
+	else if (*(uint64_t*)b < *(uint64_t*)a) return 1;
+	else return -1;
 }
 
-// Compare countKeys structure
-int compar_special_int(const void * a, const void * b) {
-	return (((countKeys *)b)->count - ((countKeys *)a)->count);
-}
 
-countKeys * uniqsort(uint64_t * possibleKeys, uint32_t size) {
-	int i, j = 0;
-	int count = 0;
-	countKeys *our_counts;
-	
-	qsort(possibleKeys, size, sizeof (uint64_t), compar_int);
-	
-	our_counts = calloc(size, sizeof(countKeys));
-	if (our_counts == NULL) {
-		PrintAndLog("Memory allocation error for our_counts");
-		return NULL;
+// create the intersection (common members) of two sorted lists. Lists are terminated by -1. Result will be in list1. Number of elements is returned.
+static uint32_t intersection(uint64_t *list1, uint64_t *list2)
+{
+	if (list1 == NULL || list2 == NULL) {
+		return 0;
 	}
-	
-	for (i = 0; i < size; i++) {
-        if (possibleKeys[i+1] == possibleKeys[i]) { 
-			count++;
-		} else {
-			our_counts[j].key = possibleKeys[i];
-			our_counts[j].count = count;
-			j++;
-			count=0;
+	uint64_t *p1, *p2, *p3;
+	p1 = p3 = list1;
+	p2 = list2;
+
+	while ( *p1 != -1 && *p2 != -1 ) {
+		if (compare_uint64(p1, p2) == 0) {
+			*p3++ = *p1++;
+			p2++;
+		}
+		else {
+			while (compare_uint64(p1, p2) < 0) ++p1;
+			while (compare_uint64(p1, p2) > 0) ++p2;
+		}
+	}
+	*p3 = -1;
+	return p3 - list1;
+}
+
+
+// Darkside attack (hf mf mifare)
+static uint32_t nonce2key(uint32_t uid, uint32_t nt, uint32_t nr, uint32_t ar, uint64_t par_info, uint64_t ks_info, uint64_t **keys) {
+	struct Crypto1State *states;
+	uint32_t i, pos;
+	uint8_t bt, ks3x[8], par[8][8];
+	uint64_t key_recovered;
+	uint64_t *keylist;
+
+	// Reset the last three significant bits of the reader nonce
+	nr &= 0xffffff1f;
+
+	for (pos=0; pos<8; pos++) {
+		ks3x[7-pos] = (ks_info >> (pos*8)) & 0x0f;
+		bt = (par_info >> (pos*8)) & 0xff;
+		for (i=0; i<8; i++)	{
+				par[7-pos][i] = (bt >> i) & 0x01;
 		}
 	}
-	qsort(our_counts, j, sizeof(countKeys), compar_special_int);
-	return (our_counts);
+
+	states = lfsr_common_prefix(nr, ar, ks3x, par, (par_info == 0));
+
+	if (states == NULL) {
+		*keys = NULL;
+		return 0;
+	}
+
+	keylist = (uint64_t*)states;
+
+	for (i = 0; keylist[i]; i++) {
+		lfsr_rollback_word(states+i, uid^nt, 0);
+		crypto1_get_lfsr(states+i, &key_recovered);
+		keylist[i] = key_recovered;
+	}
+	keylist[i] = -1;
+
+	*keys = keylist;
+	return i;
 }
 
-int mfnested(uint8_t blockNo, uint8_t keyType, uint8_t * key, uint8_t trgBlockNo, uint8_t trgKeyType, uint8_t * resultKeys) 
+
+int mfDarkside(uint64_t *key)
 {
-	int i, m, len;
-	uint8_t isEOF;
-	uint32_t uid;
-	fnVector * vector = NULL;
-	countKeys	*ck;
-	int lenVector = 0;
-	UsbCommand resp;
-	
-	memset(resultKeys, 0x00, 16 * 6);
+	uint32_t uid = 0;
+	uint32_t nt = 0, nr = 0, ar = 0;
+	uint64_t par_list = 0, ks_list = 0;
+	uint64_t *keylist = NULL, *last_keylist = NULL;
+	uint32_t keycount = 0;
+	int16_t isOK = 0;
 
-	// flush queue
-	WaitForResponseTimeout(CMD_ACK,NULL,100);
-	
-  UsbCommand c = {CMD_MIFARE_NESTED, {blockNo, keyType, trgBlockNo + trgKeyType * 0x100}};
-	memcpy(c.d.asBytes, key, 6);
-  SendCommand(&c);
+	UsbCommand c = {CMD_READER_MIFARE, {true, 0, 0}};
+
+	// message
+	printf("-------------------------------------------------------------------------\n");
+	printf("Executing command. Expected execution time: 25sec on average\n");
+	printf("Press button on the proxmark3 device to abort both proxmark3 and client.\n");
+	printf("-------------------------------------------------------------------------\n");
 
-	PrintAndLog("\n");
 
-	// wait cycle
 	while (true) {
-		printf(".");
-		if (ukbhit()) {
-			getchar();
-			printf("\naborted via keyboard!\n");
-			break;
+		clearCommandBuffer();
+		SendCommand(&c);
+
+		//flush queue
+		while (ukbhit()) {
+			int c = getchar(); (void) c;
 		}
 
-		if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
-			isEOF  = resp.arg[0] & 0xff;
-
-			if (isEOF) break;
-			
-			len = resp.arg[1] & 0xff;
-			if (len == 0) continue;
-			
-			memcpy(&uid, resp.d.asBytes, 4);
-			PrintAndLog("uid:%08x len=%d trgbl=%d trgkey=%x", uid, len, resp.arg[2] & 0xff, (resp.arg[2] >> 8) & 0xff);
-			vector = (fnVector *) realloc((void *)vector, (lenVector + len) * sizeof(fnVector) + 200);
-			if (vector == NULL) {
-				PrintAndLog("Memory allocation error for fnVector. len: %d bytes: %d", lenVector + len, (lenVector + len) * sizeof(fnVector)); 
+		// wait cycle
+		while (true) {
+			printf(".");
+			fflush(stdout);
+			if (ukbhit()) {
+				return -5;
 				break;
 			}
-			
-			for (i = 0; i < len; i++) {
-				vector[lenVector + i].blockNo = resp.arg[2] & 0xff;
-				vector[lenVector + i].keyType = (resp.arg[2] >> 8) & 0xff;
-				vector[lenVector + i].uid = uid;
-
-				memcpy(&vector[lenVector + i].nt,  (void *)(resp.d.asBytes + 8 + i * 8 + 0), 4);
-				memcpy(&vector[lenVector + i].ks1, (void *)(resp.d.asBytes + 8 + i * 8 + 4), 4);
+
+			UsbCommand resp;
+			if (WaitForResponseTimeout(CMD_ACK, &resp, 1000)) {
+				isOK  = resp.arg[0];
+				if (isOK < 0) {
+					return isOK;
+				}
+				uid = (uint32_t)bytes_to_num(resp.d.asBytes +  0, 4);
+				nt =  (uint32_t)bytes_to_num(resp.d.asBytes +  4, 4);
+				par_list = bytes_to_num(resp.d.asBytes +  8, 8);
+				ks_list = bytes_to_num(resp.d.asBytes +  16, 8);
+				nr = (uint32_t)bytes_to_num(resp.d.asBytes + 24, 4);
+				ar = (uint32_t)bytes_to_num(resp.d.asBytes + 28, 4);
+				break;
 			}
+		}
 
-			lenVector += len;
+		if (par_list == 0 && c.arg[0] == true) {
+			PrintAndLog("Parity is all zero. Most likely this card sends NACK on every failed authentication.");
 		}
-	}
-	
-	if (!lenVector) {
-		PrintAndLog("Got 0 keys from proxmark."); 
-		return 1;
-	}
-	printf("------------------------------------------------------------------\n");
-	
-	// calc keys
-	struct Crypto1State* revstate = NULL;
-	struct Crypto1State* revstate_start = NULL;
-	uint64_t lfsr;
-	int kcount = 0;
-	pKeys		*pk;
-	
-	if ((pk = (void *) malloc(sizeof(pKeys))) == NULL) return 1;
-	memset(pk, 0x00, sizeof(pKeys));
-	
-	for (m = 0; m < lenVector; m++) {
-		// And finally recover the first 32 bits of the key
-		revstate = lfsr_recovery32(vector[m].ks1, vector[m].nt ^ vector[m].uid);
-		if (revstate_start == NULL) revstate_start = revstate;
-	
-		while ((revstate->odd != 0x0) || (revstate->even != 0x0)) {
-			lfsr_rollback_word(revstate, vector[m].nt ^ vector[m].uid, 0);
-			crypto1_get_lfsr(revstate, &lfsr);
-
-			// Allocate a new space for keys
-			if (((kcount % MEM_CHUNK) == 0) || (kcount >= pk->size)) {
-				pk->size += MEM_CHUNK;
-//fprintf(stdout, "New chunk by %d, sizeof %d\n", kcount, pk->size * sizeof(uint64_t));
-				pk->possibleKeys = (uint64_t *) realloc((void *)pk->possibleKeys, pk->size * sizeof(uint64_t));
-				if (pk->possibleKeys == NULL) {
-					PrintAndLog("Memory allocation error for pk->possibleKeys"); 
-					return 1;
+		c.arg[0] = false;
+
+		keycount = nonce2key(uid, nt, nr, ar, par_list, ks_list, &keylist);
+
+		if (keycount == 0) {
+			PrintAndLog("Key not found (lfsr_common_prefix list is null). Nt=%08x", nt);
+			PrintAndLog("This is expected to happen in 25%% of all cases. Trying again with a different reader nonce...");
+			continue;
+		}
+
+		if (par_list == 0) {
+			qsort(keylist, keycount, sizeof(*keylist), compare_uint64);
+			keycount = intersection(last_keylist, keylist);
+			if (keycount == 0) {
+				free(last_keylist);
+				last_keylist = keylist;
+				continue;
+			}
+		}
+
+		if (keycount > 1) {
+			PrintAndLog("Found %u possible keys. Trying to authenticate with each of them ...\n", keycount);
+		} else {
+			PrintAndLog("Found a possible key. Trying to authenticate...\n");
+		}
+
+		*key = -1;
+		uint8_t keyBlock[USB_CMD_DATA_SIZE];
+		int max_keys = USB_CMD_DATA_SIZE/6;
+		for (int i = 0; i < keycount; i += max_keys) {
+			int size = keycount - i > max_keys ? max_keys : keycount - i;
+			for (int j = 0; j < size; j++) {
+				if (par_list == 0) {
+					num_to_bytes(last_keylist[i*max_keys + j], 6, keyBlock+(j*6));
+				} else {
+					num_to_bytes(keylist[i*max_keys + j], 6, keyBlock+(j*6));
 				}
 			}
-			pk->possibleKeys[kcount] = lfsr;
-			kcount++;
-			revstate++;
+			if (!mfCheckKeys(0, 0, false, size, keyBlock, key)) {
+				break;
+			}
 		}
-	free(revstate_start);
-	revstate_start = NULL;
 
-	}
-	
-	// Truncate
-	if (kcount != 0) {
-		pk->size = --kcount;
-		if ((pk->possibleKeys = (uint64_t *) realloc((void *)pk->possibleKeys, pk->size * sizeof(uint64_t))) == NULL) {
-			PrintAndLog("Memory allocation error for pk->possibleKeys"); 
-			return 1;
-		}		
+		if (*key != -1) {
+			free(last_keylist);
+			free(keylist);
+			break;
+		} else {
+			PrintAndLog("Authentication failed. Trying again...");
+			free(last_keylist);
+			last_keylist = keylist;
+		}
 	}
 
-	PrintAndLog("Total keys count:%d", kcount);
-	ck = uniqsort(pk->possibleKeys, pk->size);
+	return 0;
+}
 
-	// fill key array
-	for (i = 0; i < 16 ; i++) {
-		num_to_bytes(ck[i].key, 6, (uint8_t*)(resultKeys + i * 6));
-	}
 
-	// finalize
-	free(pk->possibleKeys);
-	free(pk);
-	free(ck);
-	free(vector);
+int mfCheckKeys (uint8_t blockNo, uint8_t keyType, bool clear_trace, uint8_t keycnt, uint8_t * keyBlock, uint64_t * key){
 
+	*key = -1;
+
+	UsbCommand c = {CMD_MIFARE_CHKKEYS, {((blockNo & 0xff) | ((keyType & 0xff) << 8)), clear_trace, keycnt}}; 
+	memcpy(c.d.asBytes, keyBlock, 6 * keycnt);
+	SendCommand(&c);
+
+	UsbCommand resp;
+	if (!WaitForResponseTimeout(CMD_ACK,&resp,3000)) return 1; 
+	if ((resp.arg[0] & 0xff) != 0x01) return 2;
+	*key = bytes_to_num(resp.d.asBytes, 6);
 	return 0;
 }
 
-int mfCheckKeys (uint8_t blockNo, uint8_t keyType, uint8_t keycnt, uint8_t * keyBlock, uint64_t * key){
-	*key = 0;
+int mfCheckKeysSec(uint8_t sectorCnt, uint8_t keyType, uint8_t timeout14a, bool clear_trace, uint8_t keycnt, uint8_t * keyBlock, sector_t * e_sector){
+
+	uint8_t keyPtr = 0;
+
+	if (e_sector == NULL)
+		return -1;
 
-  UsbCommand c = {CMD_MIFARE_CHKKEYS, {blockNo, keyType, keycnt}};
+	UsbCommand c = {CMD_MIFARE_CHKKEYS, {((sectorCnt & 0xff) | ((keyType & 0xff) << 8)), (clear_trace | 0x02)|((timeout14a & 0xff) << 8), keycnt}}; 
 	memcpy(c.d.asBytes, keyBlock, 6 * keycnt);
-  SendCommand(&c);
+	SendCommand(&c);
 
 	UsbCommand resp;
-	if (!WaitForResponseTimeout(CMD_ACK,&resp,3000)) return 1;
+	if (!WaitForResponseTimeoutW(CMD_ACK, &resp, MAX(3000, 1000 + 13 * sectorCnt * keycnt * (keyType == 2 ? 2 : 1)), false)) return 1; // timeout: 13 ms / fail auth
 	if ((resp.arg[0] & 0xff) != 0x01) return 2;
-	*key = bytes_to_num(resp.d.asBytes, 6);
+	
+	bool foundAKey = false;
+	for(int sec = 0; sec < sectorCnt; sec++){
+		for(int keyAB = 0; keyAB < 2; keyAB++){
+			keyPtr = *(resp.d.asBytes + keyAB * 40 + sec);
+			if (keyPtr){
+				e_sector[sec].foundKey[keyAB] = true;
+				e_sector[sec].Key[keyAB] = bytes_to_num(keyBlock + (keyPtr - 1) * 6, 6);
+				foundAKey = true;
+			}
+		}
+	}
+	return foundAKey ? 0 : 3;
+}
+
+// Compare 16 Bits out of cryptostate
+int Compare16Bits(const void * a, const void * b) {
+	if ((*(uint64_t*)b & 0x00ff000000ff0000) == (*(uint64_t*)a & 0x00ff000000ff0000)) return 0;
+	else if ((*(uint64_t*)b & 0x00ff000000ff0000) > (*(uint64_t*)a & 0x00ff000000ff0000)) return 1;
+	else return -1;
+}
+
+typedef
+	struct {
+		union {
+			struct Crypto1State *slhead;
+			uint64_t *keyhead;
+		} head;
+		union {
+			struct Crypto1State *sltail;
+			uint64_t *keytail;
+		} tail;
+		uint32_t len;
+		uint32_t uid;
+		uint32_t blockNo;
+		uint32_t keyType;
+		uint32_t nt;
+		uint32_t ks1;
+	} StateList_t;
+
+
+// wrapper function for multi-threaded lfsr_recovery32
+void
+#ifdef __has_attribute
+#if __has_attribute(force_align_arg_pointer)
+__attribute__((force_align_arg_pointer)) 
+#endif
+#endif
+*nested_worker_thread(void *arg)
+{
+	struct Crypto1State *p1;
+	StateList_t *statelist = arg;
+
+	statelist->head.slhead = lfsr_recovery32(statelist->ks1, statelist->nt ^ statelist->uid);
+	for (p1 = statelist->head.slhead; *(uint64_t *)p1 != 0; p1++);
+	statelist->len = p1 - statelist->head.slhead;
+	statelist->tail.sltail = --p1;
+	qsort(statelist->head.slhead, statelist->len, sizeof(uint64_t), Compare16Bits);
+
+	return statelist->head.slhead;
+}
+
+
+int mfnested(uint8_t blockNo, uint8_t keyType, uint8_t *key, uint8_t trgBlockNo, uint8_t trgKeyType, uint8_t *resultKey, bool calibrate)
+{
+	uint16_t i;
+	uint32_t uid;
+	UsbCommand resp;
+
+	StateList_t statelists[2];
+	struct Crypto1State *p1, *p2, *p3, *p4;
+
+	// flush queue
+	(void)WaitForResponseTimeout(CMD_ACK,NULL,100);
+
+	UsbCommand c = {CMD_MIFARE_NESTED, {blockNo + keyType * 0x100, trgBlockNo + trgKeyType * 0x100, calibrate}};
+	memcpy(c.d.asBytes, key, 6);
+	SendCommand(&c);
+
+	if (!WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {
+		return -1;
+	}
+
+	if (resp.arg[0]) {
+		return resp.arg[0];  // error during nested
+	}
+
+	memcpy(&uid, resp.d.asBytes, 4);
+	PrintAndLog("uid:%08x trgbl=%d trgkey=%x", uid, (uint16_t)resp.arg[2] & 0xff, (uint16_t)resp.arg[2] >> 8);
+
+	for (i = 0; i < 2; i++) {
+		statelists[i].blockNo = resp.arg[2] & 0xff;
+		statelists[i].keyType = (resp.arg[2] >> 8) & 0xff;
+		statelists[i].uid = uid;
+		memcpy(&statelists[i].nt,  (void *)(resp.d.asBytes + 4 + i * 8 + 0), 4);
+		memcpy(&statelists[i].ks1, (void *)(resp.d.asBytes + 4 + i * 8 + 4), 4);
+	}
+
+	// calc keys
+
+	pthread_t thread_id[2];
+
+	// create and run worker threads
+	for (i = 0; i < 2; i++) {
+		pthread_create(thread_id + i, NULL, nested_worker_thread, &statelists[i]);
+	}
+
+	// wait for threads to terminate:
+	for (i = 0; i < 2; i++) {
+		pthread_join(thread_id[i], (void*)&statelists[i].head.slhead);
+	}
+
+
+	// the first 16 Bits of the cryptostate already contain part of our key.
+	// Create the intersection of the two lists based on these 16 Bits and
+	// roll back the cryptostate
+	p1 = p3 = statelists[0].head.slhead;
+	p2 = p4 = statelists[1].head.slhead;
+	while (p1 <= statelists[0].tail.sltail && p2 <= statelists[1].tail.sltail) {
+		if (Compare16Bits(p1, p2) == 0) {
+			struct Crypto1State savestate, *savep = &savestate;
+			savestate = *p1;
+			while(Compare16Bits(p1, savep) == 0 && p1 <= statelists[0].tail.sltail) {
+				*p3 = *p1;
+				lfsr_rollback_word(p3, statelists[0].nt ^ statelists[0].uid, 0);
+				p3++;
+				p1++;
+			}
+			savestate = *p2;
+			while(Compare16Bits(p2, savep) == 0 && p2 <= statelists[1].tail.sltail) {
+				*p4 = *p2;
+				lfsr_rollback_word(p4, statelists[1].nt ^ statelists[1].uid, 0);
+				p4++;
+				p2++;
+			}
+		}
+		else {
+			while (Compare16Bits(p1, p2) == -1) p1++;
+			while (Compare16Bits(p1, p2) == 1) p2++;
+		}
+	}
+	*(uint64_t*)p3 = -1;
+	*(uint64_t*)p4 = -1;
+	statelists[0].len = p3 - statelists[0].head.slhead;
+	statelists[1].len = p4 - statelists[1].head.slhead;
+	statelists[0].tail.sltail=--p3;
+	statelists[1].tail.sltail=--p4;
+
+	// the statelists now contain possible keys. The key we are searching for must be in the
+	// intersection of both lists. Create the intersection:
+	qsort(statelists[0].head.keyhead, statelists[0].len, sizeof(uint64_t), compare_uint64);
+	qsort(statelists[1].head.keyhead, statelists[1].len, sizeof(uint64_t), compare_uint64);
+	statelists[0].len = intersection(statelists[0].head.keyhead, statelists[1].head.keyhead);
+
+	memset(resultKey, 0, 6);
+	// The list may still contain several key candidates. Test each of them with mfCheckKeys
+	for (i = 0; i < statelists[0].len; i++) {
+		uint8_t keyBlock[6];
+		uint64_t key64;
+		crypto1_get_lfsr(statelists[0].head.slhead + i, &key64);
+		num_to_bytes(key64, 6, keyBlock);
+		key64 = 0;
+		if (!mfCheckKeys(statelists[0].blockNo, statelists[0].keyType, false, 1, keyBlock, &key64)) {
+			num_to_bytes(key64, 6, resultKey);
+			break;
+		}
+	}
+
+	free(statelists[0].head.slhead);
+	free(statelists[1].head.slhead);
+
 	return 0;
 }
 
@@ -208,37 +443,23 @@ int mfEmlGetMem(uint8_t *data, int blockNum, int blocksCount) {
 
 int mfEmlSetMem(uint8_t *data, int blockNum, int blocksCount) {
 	UsbCommand c = {CMD_MIFARE_EML_MEMSET, {blockNum, blocksCount, 0}};
-	memcpy(c.d.asBytes, data, blocksCount * 16); 
+	memcpy(c.d.asBytes, data, blocksCount * 16);
 	SendCommand(&c);
 	return 0;
 }
 
 // "MAGIC" CARD
 
-int mfCSetUID(uint8_t *uid, uint8_t *oldUID, int wantWipe) {
-	uint8_t block0[16];
-	memset(block0, 0, 16);
-	memcpy(block0, uid, 4); 
-	block0[4] = block0[0]^block0[1]^block0[2]^block0[3]; // Mifare UID BCC
-	// mifare classic SAK(byte 5) and ATQA(byte 6 and 7)
-	block0[5] = 0x88;
-	block0[6] = 0x04;
-	block0[7] = 0x00;
-	
-	return mfCSetBlock(0, block0, oldUID, wantWipe, CSETBLOCK_SINGLE_OPER);
-}
-
-int mfCSetBlock(uint8_t blockNo, uint8_t *data, uint8_t *uid, int wantWipe, uint8_t params) {
+int mfCGetBlock(uint8_t blockNo, uint8_t *data, uint8_t params) {
 	uint8_t isOK = 0;
 
-	UsbCommand c = {CMD_MIFARE_EML_CSETBLOCK, {wantWipe, params & (0xFE | (uid == NULL ? 0:1)), blockNo}};
-	memcpy(c.d.asBytes, data, 16); 
+	UsbCommand c = {CMD_MIFARE_CGETBLOCK, {params, 0, blockNo}};
 	SendCommand(&c);
 
-  UsbCommand resp;
+	UsbCommand resp;
 	if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
 		isOK  = resp.arg[0] & 0xff;
-		if (uid != NULL) memcpy(uid, resp.d.asBytes, 4);
+		memcpy(data, resp.d.asBytes, 16);
 		if (!isOK) return 2;
 	} else {
 		PrintAndLog("Command execute timeout");
@@ -247,33 +468,113 @@ int mfCSetBlock(uint8_t blockNo, uint8_t *data, uint8_t *uid, int wantWipe, uint
 	return 0;
 }
 
-int mfCGetBlock(uint8_t blockNo, uint8_t *data, uint8_t params) {
-	uint8_t isOK = 0;
+int mfCSetBlock(uint8_t blockNo, uint8_t *data, uint8_t *uid, bool wantWipe, uint8_t params) {
 
-	UsbCommand c = {CMD_MIFARE_EML_CGETBLOCK, {params, 0, blockNo}};
+	uint8_t isOK = 0;
+	UsbCommand c = {CMD_MIFARE_CSETBLOCK, {wantWipe, params & (0xFE | (uid == NULL ? 0:1)), blockNo}};
+	memcpy(c.d.asBytes, data, 16);
 	SendCommand(&c);
 
-  UsbCommand resp;
-	if (WaitForResponseTimeout(CMD_ACK,&resp,1500)) {
+	UsbCommand resp;
+	if (WaitForResponseTimeout(CMD_ACK, &resp, 1500)) {
 		isOK  = resp.arg[0] & 0xff;
-		memcpy(data, resp.d.asBytes, 16);
-		if (!isOK) return 2;
+		if (uid != NULL)
+			memcpy(uid, resp.d.asBytes, 4);
+		if (!isOK)
+			return 2;
 	} else {
 		PrintAndLog("Command execute timeout");
 		return 1;
 	}
+
+	return 0;
+}
+
+int mfCWipe(uint32_t numSectors, bool gen1b, bool wantWipe, bool wantFill) {
+	uint8_t isOK = 0;
+	uint8_t cmdParams = wantWipe + wantFill * 0x02 + gen1b * 0x04;
+	UsbCommand c = {CMD_MIFARE_CWIPE, {numSectors, cmdParams, 0}};
+	SendCommand(&c);
+
+	UsbCommand resp;
+	WaitForResponse(CMD_ACK,&resp);
+	isOK  = resp.arg[0] & 0xff;
+	
+	return isOK;
+}
+
+int mfCSetUID(uint8_t *uid, uint8_t *atqa, uint8_t *sak, uint8_t *oldUID) {
+	uint8_t oldblock0[16] = {0x00};
+	uint8_t block0[16] = {0x00};
+	int gen = 0, res;
+
+	gen = mfCIdentify();
+
+	/* generation 1a magic card by default */
+	uint8_t cmdParams = CSETBLOCK_SINGLE_OPER;
+	if (gen == 2) {
+		/* generation 1b magic card */
+		cmdParams = CSETBLOCK_SINGLE_OPER | CSETBLOCK_MAGIC_1B;
+	}
+	
+	res = mfCGetBlock(0, oldblock0, cmdParams);
+
+	if (res == 0) {
+		memcpy(block0, oldblock0, 16);
+		PrintAndLog("old block 0:  %s", sprint_hex(block0,16));
+	} else {
+		PrintAndLog("Couldn't get old data. Will write over the last bytes of Block 0.");
+	}
+
+	// fill in the new values
+	// UID
+	memcpy(block0, uid, 4);
+	// Mifare UID BCC
+	block0[4] = block0[0] ^ block0[1] ^ block0[2] ^ block0[3];
+	// mifare classic SAK(byte 5) and ATQA(byte 6 and 7, reversed)
+	if (sak != NULL)
+		block0[5] = sak[0];
+	if (atqa != NULL) {
+		block0[6] = atqa[1];
+		block0[7] = atqa[0];
+	}
+	PrintAndLog("new block 0:  %s", sprint_hex(block0, 16));
+
+	res = mfCSetBlock(0, block0, oldUID, false, cmdParams);
+	if (res) {
+		PrintAndLog("Can't set block 0. Error: %d", res);
+		return res;
+	}
+	
 	return 0;
 }
 
+int mfCIdentify() {
+	UsbCommand c = {CMD_MIFARE_CIDENT, {0, 0, 0}};
+	SendCommand(&c);
+	UsbCommand resp;
+	WaitForResponse(CMD_ACK,&resp);
+
+	uint8_t isGeneration = resp.arg[0] & 0xff;
+	switch( isGeneration ){
+		case 1: PrintAndLog("Chinese magic backdoor commands (GEN 1a) detected"); break;
+		case 2: PrintAndLog("Chinese magic backdoor command (GEN 1b) detected"); break;
+		default: PrintAndLog("No chinese magic backdoor command detected"); break;
+	}
+
+	return (int) isGeneration;
+}
+
+
 // SNIFFER
 
 // constants
 static uint8_t trailerAccessBytes[4] = {0x08, 0x77, 0x8F, 0x00};
 
 // variables
-char logHexFileName[200] = {0x00};
+char logHexFileName[FILE_PATH_SIZE] = {0x00};
 static uint8_t traceCard[4096] = {0x00};
-static char traceFileName[20];
+static char traceFileName[FILE_PATH_SIZE] = {0x00};
 static int traceState = TRACE_IDLE;
 static uint8_t traceCurBlock = 0;
 static uint8_t traceCurKey = 0;
@@ -282,24 +583,26 @@ struct Crypto1State *traceCrypto1 = NULL;
 
 struct Crypto1State *revstate;
 uint64_t lfsr;
+uint64_t ui64Key;
 uint32_t ks2;
 uint32_t ks3;
 
-uint32_t uid;     // serial number
-uint32_t nt;      // tag challenge
-uint32_t nt_par; 
-uint32_t nr_enc;  // encrypted reader challenge
-uint32_t ar_enc;  // encrypted reader response
-uint32_t nr_ar_par; 
-uint32_t at_enc;  // encrypted tag response
-uint32_t at_par; 
+uint32_t uid;       // serial number
+uint32_t nt;        // tag challenge
+uint32_t nt_enc;    // encrypted tag challenge
+uint8_t nt_enc_par; // encrypted tag challenge parity
+uint32_t nr_enc;    // encrypted reader challenge
+uint32_t ar_enc;    // encrypted reader response
+uint8_t ar_enc_par; // encrypted reader response parity
+uint32_t at_enc;    // encrypted tag response
+uint8_t at_enc_par; // encrypted tag response parity
 
 int isTraceCardEmpty(void) {
 	return ((traceCard[0] == 0) && (traceCard[1] == 0) && (traceCard[2] == 0) && (traceCard[3] == 0));
 }
 
 int isBlockEmpty(int blockN) {
-	for (int i = 0; i < 16; i++) 
+	for (int i = 0; i < 16; i++)
 		if (traceCard[blockN * 16 + i] != 0) return 0;
 
 	return 1;
@@ -309,28 +612,56 @@ int isBlockTrailer(int blockN) {
  return ((blockN & 0x03) == 0x03);
 }
 
+int saveTraceCard(void) {
+	FILE * f;
+
+	if ((!strlen(traceFileName)) || (isTraceCardEmpty())) return 0;
+
+	f = fopen(traceFileName, "w+");
+	if ( !f ) return 1;
+
+	for (int i = 0; i < 64; i++) {  // blocks
+		for (int j = 0; j < 16; j++)  // bytes
+			fprintf(f, "%02x", *(traceCard + i * 16 + j));
+		if (i < 63)
+			fprintf(f,"\n");
+	}
+	fclose(f);
+	return 0;
+}
+
 int loadTraceCard(uint8_t *tuid) {
 	FILE * f;
-	char buf[64];
-	uint8_t buf8[64];
+	char buf[64] = {0x00};
+	uint8_t buf8[64] = {0x00};
 	int i, blockNum;
-	
-	if (!isTraceCardEmpty()) saveTraceCard();
+
+	if (!isTraceCardEmpty())
+		saveTraceCard();
+
 	memset(traceCard, 0x00, 4096);
 	memcpy(traceCard, tuid + 3, 4);
+
 	FillFileNameByUID(traceFileName, tuid, ".eml", 7);
 
 	f = fopen(traceFileName, "r");
 	if (!f) return 1;
-	
+
 	blockNum = 0;
+
 	while(!feof(f)){
+
 		memset(buf, 0, sizeof(buf));
-		fgets(buf, sizeof(buf), f);
+		if (fgets(buf, sizeof(buf), f) == NULL) {
+			PrintAndLog("File reading error.");
+			fclose(f);
+			return 2;
+    	}
 
 		if (strlen(buf) < 32){
 			if (feof(f)) break;
 			PrintAndLog("File content error. Block data must include 32 HEX symbols");
+			fclose(f);
 			return 2;
 		}
 		for (i = 0; i < 32; i += 2)
@@ -345,34 +676,22 @@ int loadTraceCard(uint8_t *tuid) {
 	return 0;
 }
 
-int saveTraceCard(void) {
-	FILE * f;
-	
-	if ((!strlen(traceFileName)) || (isTraceCardEmpty())) return 0;
-	
-	f = fopen(traceFileName, "w+");
-	for (int i = 0; i < 64; i++) {  // blocks
-		for (int j = 0; j < 16; j++)  // bytes
-			fprintf(f, "%02x", *(traceCard + i * 16 + j)); 
-		fprintf(f,"\n");
-	}
-	fclose(f);
-
-	return 0;
-}
-
 int mfTraceInit(uint8_t *tuid, uint8_t *atqa, uint8_t sak, bool wantSaveToEmlFile) {
 
-	if (traceCrypto1) crypto1_destroy(traceCrypto1);
+	if (traceCrypto1)
+		crypto1_destroy(traceCrypto1);
+
 	traceCrypto1 = NULL;
 
-	if (wantSaveToEmlFile) loadTraceCard(tuid);
+	if (wantSaveToEmlFile)
+		loadTraceCard(tuid);
+
 	traceCard[4] = traceCard[0] ^ traceCard[1] ^ traceCard[2] ^ traceCard[3];
 	traceCard[5] = sak;
 	memcpy(&traceCard[6], atqa, 2);
 	traceCurBlock = 0;
 	uid = bytes_to_num(tuid + 3, 4);
-	
+
 	traceState = TRACE_IDLE;
 
 	return 0;
@@ -381,7 +700,7 @@ int mfTraceInit(uint8_t *tuid, uint8_t *atqa, uint8_t sak, bool wantSaveToEmlFil
 void mf_crypto1_decrypt(struct Crypto1State *pcs, uint8_t *data, int len, bool isEncrypted){
 	uint8_t	bt = 0;
 	int i;
-	
+
 	if (len != 1) {
 		for (i = 0; i < len; i++)
 			data[i] = crypto1_byte(pcs, 0x00, isEncrypted) ^ data[i];
@@ -389,14 +708,42 @@ void mf_crypto1_decrypt(struct Crypto1State *pcs, uint8_t *data, int len, bool i
 		bt = 0;
 		for (i = 0; i < 4; i++)
 			bt |= (crypto1_bit(pcs, 0, isEncrypted) ^ BIT(data[0], i)) << i;
-				
+
 		data[0] = bt;
 	}
 	return;
 }
 
+bool NTParityCheck(uint32_t ntx) {
+	if (
+		(oddparity8(ntx >> 8 & 0xff) ^ (ntx & 0x01) ^ ((nt_enc_par >> 5) & 0x01) ^ (nt_enc & 0x01)) ||
+		(oddparity8(ntx >> 16 & 0xff) ^ (ntx >> 8 & 0x01) ^ ((nt_enc_par >> 6) & 0x01) ^ (nt_enc >> 8 & 0x01)) ||
+		(oddparity8(ntx >> 24 & 0xff) ^ (ntx >> 16 & 0x01) ^ ((nt_enc_par >> 7) & 0x01) ^ (nt_enc >> 16 & 0x01))
+		)
+		return false;
+	
+	uint32_t ar = prng_successor(ntx, 64);
+	if (
+		(oddparity8(ar >> 8 & 0xff) ^ (ar & 0x01) ^ ((ar_enc_par >> 5) & 0x01) ^ (ar_enc & 0x01)) ||
+		(oddparity8(ar >> 16 & 0xff) ^ (ar >> 8 & 0x01) ^ ((ar_enc_par >> 6) & 0x01) ^ (ar_enc >> 8 & 0x01)) ||
+		(oddparity8(ar >> 24 & 0xff) ^ (ar >> 16 & 0x01) ^ ((ar_enc_par >> 7) & 0x01) ^ (ar_enc >> 16 & 0x01))
+		)
+		return false;
+
+	uint32_t at = prng_successor(ntx, 96);
+	if (
+		(oddparity8(ar & 0xff) ^ (at >> 24 & 0x01) ^ ((ar_enc_par >> 4) & 0x01) ^ (at_enc >> 24 & 0x01)) ||
+		(oddparity8(at >> 8 & 0xff) ^ (at & 0x01) ^ ((at_enc_par >> 5) & 0x01) ^ (at_enc & 0x01)) ||
+		(oddparity8(at >> 16 & 0xff) ^ (at >> 8 & 0x01) ^ ((at_enc_par >> 6) & 0x01) ^ (at_enc >> 8 & 0x01)) ||
+		(oddparity8(at >> 24 & 0xff) ^ (at >> 16 & 0x01) ^ ((at_enc_par >> 7) & 0x01) ^ (at_enc >> 16 & 0x01))
+		)
+		return false;
+		
+	return true;
+}
+
 
-int mfTraceDecode(uint8_t *data_src, int len, uint32_t parity, bool wantSaveToEmlFile) {
+int mfTraceDecode(uint8_t *data_src, int len, uint8_t parity, bool wantSaveToEmlFile) {
 	uint8_t data[64];
 
 	if (traceState == TRACE_ERROR) return 1;
@@ -404,24 +751,26 @@ int mfTraceDecode(uint8_t *data_src, int len, uint32_t parity, bool wantSaveToEm
 		traceState = TRACE_ERROR;
 		return 1;
 	}
-	
+
 	memcpy(data, data_src, len);
 	if ((traceCrypto1) && ((traceState == TRACE_IDLE) || (traceState > TRACE_AUTH_OK))) {
 		mf_crypto1_decrypt(traceCrypto1, data, len, 0);
-		PrintAndLog("dec> %s", sprint_hex(data, len));
-		AddLogHex(logHexFileName, "dec> ", data, len); 
+		uint8_t parity[16];
+		oddparitybuf(data, len, parity);
+		PrintAndLog("dec> %s [%s]", sprint_hex(data, len), printBitsPar(parity, len));
+		AddLogHex(logHexFileName, "dec> ", data, len);
 	}
-	
+
 	switch (traceState) {
-	case TRACE_IDLE: 
+	case TRACE_IDLE:
 		// check packet crc16!
 		if ((len >= 4) && (!CheckCrc14443(CRC_14443_A, data, len))) {
 			PrintAndLog("dec> CRC ERROR!!!");
-			AddLogLine(logHexFileName, "dec> ", "CRC ERROR!!!"); 
+			AddLogLine(logHexFileName, "dec> ", "CRC ERROR!!!");
 			traceState = TRACE_ERROR;  // do not decrypt the next commands
 			return 1;
 		}
-		
+
 		// AUTHENTICATION
 		if ((len ==4) && ((data[0] == 0x60) || (data[0] == 0x61))) {
 			traceState = TRACE_AUTH1;
@@ -449,11 +798,11 @@ int mfTraceDecode(uint8_t *data_src, int len, uint32_t parity, bool wantSaveToEm
 			traceState = TRACE_ERROR;  // do not decrypt the next commands
 			return 0;
 		}
-		
+
 		return 0;
 	break;
-	
-	case TRACE_READ_DATA: 
+
+	case TRACE_READ_DATA:
 		if (len == 18) {
 			traceState = TRACE_IDLE;
 
@@ -470,8 +819,8 @@ int mfTraceDecode(uint8_t *data_src, int len, uint32_t parity, bool wantSaveToEm
 		}
 	break;
 
-	case TRACE_WRITE_OK: 
-		if ((len == 1) && (data[0] = 0x0a)) {
+	case TRACE_WRITE_OK:
+		if ((len == 1) && (data[0] == 0x0a)) {
 			traceState = TRACE_WRITE_DATA;
 
 			return 0;
@@ -481,7 +830,7 @@ int mfTraceDecode(uint8_t *data_src, int len, uint32_t parity, bool wantSaveToEm
 		}
 	break;
 
-	case TRACE_WRITE_DATA: 
+	case TRACE_WRITE_DATA:
 		if (len == 18) {
 			traceState = TRACE_IDLE;
 
@@ -494,12 +843,15 @@ int mfTraceDecode(uint8_t *data_src, int len, uint32_t parity, bool wantSaveToEm
 		}
 	break;
 
-	case TRACE_AUTH1: 
+	case TRACE_AUTH1:
 		if (len == 4) {
 			traceState = TRACE_AUTH2;
-
-			nt = bytes_to_num(data, 4);
-			nt_par = parity;
+			if (!traceCrypto1) {
+				nt = bytes_to_num(data, 4);
+			} else {
+				nt_enc = bytes_to_num(data, 4);
+				nt_enc_par = parity;
+			}
 			return 0;
 		} else {
 			traceState = TRACE_ERROR;
@@ -507,13 +859,13 @@ int mfTraceDecode(uint8_t *data_src, int len, uint32_t parity, bool wantSaveToEm
 		}
 	break;
 
-	case TRACE_AUTH2: 
+	case TRACE_AUTH2:
 		if (len == 8) {
 			traceState = TRACE_AUTH_OK;
 
 			nr_enc = bytes_to_num(data, 4);
 			ar_enc = bytes_to_num(data + 4, 4);
-			nr_ar_par = parity;
+			ar_enc_par = parity << 4;
 			return 0;
 		} else {
 			traceState = TRACE_ERROR;
@@ -521,15 +873,15 @@ int mfTraceDecode(uint8_t *data_src, int len, uint32_t parity, bool wantSaveToEm
 		}
 	break;
 
-	case TRACE_AUTH_OK: 
+	case TRACE_AUTH_OK:
 		if (len ==4) {
 			traceState = TRACE_IDLE;
 
 			at_enc = bytes_to_num(data, 4);
-			at_par = parity;
-			
-			//  decode key here)
+			at_enc_par = parity;
 			if (!traceCrypto1) {
+
+				//  decode key here)
 				ks2 = ar_enc ^ prng_successor(nt, 64);
 				ks3 = at_enc ^ prng_successor(nt, 96);
 				revstate = lfsr_recovery64(ks2, ks3);
@@ -537,22 +889,83 @@ int mfTraceDecode(uint8_t *data_src, int len, uint32_t parity, bool wantSaveToEm
 				lfsr_rollback_word(revstate, 0, 0);
 				lfsr_rollback_word(revstate, nr_enc, 1);
 				lfsr_rollback_word(revstate, uid ^ nt, 0);
-			}else{
-				ks2 = ar_enc ^ prng_successor(nt, 64);
-				ks3 = at_enc ^ prng_successor(nt, 96);
-				revstate = lfsr_recovery64(ks2, ks3);
-				lfsr_rollback_word(revstate, 0, 0);
-				lfsr_rollback_word(revstate, 0, 0);
-				lfsr_rollback_word(revstate, nr_enc, 1);
-				lfsr_rollback_word(revstate, uid ^ nt, 0);
+
+				crypto1_get_lfsr(revstate, &lfsr);
+				crypto1_destroy(revstate);
+				ui64Key = lfsr;
+				printf("key> probable key:%x%x Prng:%s ks2:%08x ks3:%08x\n", 
+					(unsigned int)((lfsr & 0xFFFFFFFF00000000) >> 32), (unsigned int)(lfsr & 0xFFFFFFFF), 
+					validate_prng_nonce(nt) ? "WEAK": "HARDEND",
+					ks2,
+					ks3);
+				AddLogUint64(logHexFileName, "key> ", lfsr);
+			} else {
+				if (validate_prng_nonce(nt)) {
+					struct Crypto1State *pcs;
+					pcs = crypto1_create(ui64Key);
+					uint32_t nt1 = crypto1_word(pcs, nt_enc ^ uid, 1) ^ nt_enc;
+					uint32_t ar = prng_successor(nt1, 64);
+					uint32_t at = prng_successor(nt1, 96);
+					printf("key> nested auth uid: %08x nt: %08x nt_parity: %s ar: %08x at: %08x\n", uid, nt1, printBitsPar(&nt_enc_par, 4), ar, at);
+					uint32_t nr1 = crypto1_word(pcs, nr_enc, 1) ^ nr_enc;
+					uint32_t ar1 = crypto1_word(pcs, 0, 0) ^ ar_enc;
+					uint32_t at1 = crypto1_word(pcs, 0, 0) ^ at_enc;
+					crypto1_destroy(pcs);
+					printf("key> the same key test. nr1: %08x ar1: %08x at1: %08x \n", nr1, ar1, at1);
+
+					if (NTParityCheck(nt1))
+						printf("key> the same key test OK. key=%x%x\n", (unsigned int)((ui64Key & 0xFFFFFFFF00000000) >> 32), (unsigned int)(ui64Key & 0xFFFFFFFF));
+					else
+						printf("key> the same key test. check nt parity error.\n");
+					
+					uint32_t ntc = prng_successor(nt, 90);
+					uint32_t ntx = 0;
+					int ntcnt = 0;
+					for (int i = 0; i < 16383; i++) {
+						ntc = prng_successor(ntc, 1);
+						if (NTParityCheck(ntc)){
+							if (!ntcnt)
+								ntx = ntc;
+							ntcnt++;
+						}						
+					}
+					if (ntcnt)
+						printf("key> nt candidate=%08x nonce distance=%d candidates count=%d\n", ntx, nonce_distance(nt, ntx), ntcnt);
+					else
+						printf("key> don't have any nt candidate( \n");
+
+					nt = ntx;
+					ks2 = ar_enc ^ prng_successor(ntx, 64);
+					ks3 = at_enc ^ prng_successor(ntx, 96);
+
+					// decode key
+					revstate = lfsr_recovery64(ks2, ks3);
+					lfsr_rollback_word(revstate, 0, 0);
+					lfsr_rollback_word(revstate, 0, 0);
+					lfsr_rollback_word(revstate, nr_enc, 1);
+					lfsr_rollback_word(revstate, uid ^ nt, 0);
+
+					crypto1_get_lfsr(revstate, &lfsr);
+					crypto1_destroy(revstate);
+					ui64Key = lfsr;
+					printf("key> probable key:%x%x  ks2:%08x ks3:%08x\n", 
+						(unsigned int)((lfsr & 0xFFFFFFFF00000000) >> 32), (unsigned int)(lfsr & 0xFFFFFFFF),
+						ks2,
+						ks3);
+					AddLogUint64(logHexFileName, "key> ", lfsr);
+				} else {				
+					printf("key> hardnested not implemented!\n");
+				
+					crypto1_destroy(traceCrypto1);
+
+					// not implemented
+					traceState = TRACE_ERROR;
+				}
 			}
-			crypto1_get_lfsr(revstate, &lfsr);
-			printf("key> %x%x\n", (unsigned int)((lfsr & 0xFFFFFFFF00000000) >> 32), (unsigned int)(lfsr & 0xFFFFFFFF));
-			AddLogUint64(logHexFileName, "key> ", lfsr); 
-			
+
 			int blockShift = ((traceCurBlock & 0xFC) + 3) * 16;
 			if (isBlockEmpty((traceCurBlock & 0xFC) + 3)) memcpy(traceCard + blockShift + 6, trailerAccessBytes, 4);
-			
+
 			if (traceCurKey) {
 				num_to_bytes(lfsr, 6, traceCard + blockShift + 10);
 			} else {
@@ -563,18 +976,9 @@ int mfTraceDecode(uint8_t *data_src, int len, uint32_t parity, bool wantSaveToEm
 			if (traceCrypto1) {
 				crypto1_destroy(traceCrypto1);
 			}
-			
+
 			// set cryptosystem state
 			traceCrypto1 = lfsr_recovery64(ks2, ks3);
-			
-//	nt = crypto1_word(traceCrypto1, nt ^ uid, 1) ^ nt;
-
-	/*	traceCrypto1 = crypto1_create(lfsr); // key in lfsr
-		crypto1_word(traceCrypto1, nt ^ uid, 0);
-		crypto1_word(traceCrypto1, ar, 1);
-		crypto1_word(traceCrypto1, 0, 0);
-		crypto1_word(traceCrypto1, 0, 0);*/
-	
 			return 0;
 		} else {
 			traceState = TRACE_ERROR;
@@ -582,10 +986,102 @@ int mfTraceDecode(uint8_t *data_src, int len, uint32_t parity, bool wantSaveToEm
 		}
 	break;
 
-	default: 
+	default:
 		traceState = TRACE_ERROR;
 		return 1;
 	}
 
 	return 0;
 }
+
+// DECODING
+
+int tryDecryptWord(uint32_t nt, uint32_t ar_enc, uint32_t at_enc, uint8_t *data, int len){
+	/*
+	uint32_t nt;      // tag challenge
+	uint32_t ar_enc;  // encrypted reader response
+	uint32_t at_enc;  // encrypted tag response
+	*/
+	if (traceCrypto1) {
+		crypto1_destroy(traceCrypto1);
+	}
+	ks2 = ar_enc ^ prng_successor(nt, 64);
+	ks3 = at_enc ^ prng_successor(nt, 96);
+	traceCrypto1 = lfsr_recovery64(ks2, ks3);
+
+	mf_crypto1_decrypt(traceCrypto1, data, len, 0);
+
+	PrintAndLog("Decrypted data: [%s]", sprint_hex(data,len) );
+	crypto1_destroy(traceCrypto1);
+	return 0;
+}
+
+/** validate_prng_nonce
+ * Determine if nonce is deterministic. ie: Suspectable to Darkside attack.
+ * returns
+ *   true = weak prng
+ *   false = hardend prng
+ */
+bool validate_prng_nonce(uint32_t nonce) {
+	uint16_t *dist = 0;
+	uint16_t x, i;
+
+	dist = malloc(2 << 16);
+	if(!dist)
+		return -1;
+
+	// init prng table:
+	for (x = i = 1; i; ++i) {
+		dist[(x & 0xff) << 8 | x >> 8] = i;
+		x = x >> 1 | (x ^ x >> 2 ^ x >> 3 ^ x >> 5) << 15;
+	}
+	
+	uint32_t res = (65535 - dist[nonce >> 16] + dist[nonce & 0xffff]) % 65535;
+	
+	free(dist);	
+	return (res == 16);
+}
+
+/* Detect Tag Prng, 
+* function performs a partial AUTH,  where it tries to authenticate against block0, key A, but only collects tag nonce.
+* the tag nonce is check to see if it has a predictable PRNG.
+* @returns 
+*	TRUE if tag uses WEAK prng (ie Now the NACK bug also needs to be present for Darkside attack)
+*   FALSE is tag uses HARDEND prng (ie hardnested attack possible, with known key)
+*/
+int DetectClassicPrng(void){
+
+	UsbCommand resp, respA;	
+	uint8_t cmd[] = {0x60, 0x00}; // MIFARE_AUTH_KEYA
+	uint32_t flags = ISO14A_CONNECT | ISO14A_RAW | ISO14A_APPEND_CRC | ISO14A_NO_RATS;
+	
+	UsbCommand c = {CMD_READER_ISO_14443a, {flags, sizeof(cmd), 0}};
+	memcpy(c.d.asBytes, cmd, sizeof(cmd));
+
+	clearCommandBuffer();
+	SendCommand(&c);
+	if (!WaitForResponseTimeout(CMD_ACK, &resp, 2000)) {
+        PrintAndLog("PRNG UID: Reply timeout.");
+		return -1;
+	}
+	
+	// if select tag failed.
+	if (resp.arg[0] == 0) {
+		PrintAndLog("PRNG error: selecting tag failed, can't detect prng.");
+		return -1;
+	}
+	
+	if (!WaitForResponseTimeout(CMD_ACK, &respA, 5000)) {
+        PrintAndLog("PRNG data: Reply timeout.");
+		return -1;
+	}
+
+	// check respA
+	if (respA.arg[0] != 4) {
+		PrintAndLog("PRNG data error: Wrong length: %d", respA.arg[0]);
+		return -1;
+	}
+
+	uint32_t nonce = bytes_to_num(respA.d.asBytes, respA.arg[0]);
+	return validate_prng_nonce(nonce);
+}