mirror of
https://github.com/RfidResearchGroup/proxmark3.git
synced 2024-09-22 00:06:13 +08:00
1020 lines
30 KiB
C
1020 lines
30 KiB
C
//-----------------------------------------------------------------------------
|
|
// Copyright (C) 2014
|
|
//
|
|
// This code is licensed to you under the terms of the GNU GPL, version 2 or,
|
|
// at your option, any later version. See the LICENSE.txt file for the text of
|
|
// the license.
|
|
//-----------------------------------------------------------------------------
|
|
// Low frequency commands
|
|
//-----------------------------------------------------------------------------
|
|
|
|
#include <stdlib.h>
|
|
#include <string.h>
|
|
#include "lfdemod.h"
|
|
|
|
//by marshmellow
|
|
//takes 1s and 0s and searches for EM410x format - output EM ID
|
|
uint64_t Em410xDecode(uint8_t *BitStream, size_t size)
|
|
{
|
|
//no arguments needed - built this way in case we want this to be a direct call from "data " cmds in the future
|
|
// otherwise could be a void with no arguments
|
|
//set defaults
|
|
int high=0, low=128;
|
|
uint64_t lo=0;
|
|
|
|
uint32_t i = 0;
|
|
uint32_t initLoopMax = 65;
|
|
if (initLoopMax>size) initLoopMax=size;
|
|
|
|
for (;i < initLoopMax; ++i) //65 samples should be plenty to find high and low values
|
|
{
|
|
if (BitStream[i] > high)
|
|
high = BitStream[i];
|
|
else if (BitStream[i] < low)
|
|
low = BitStream[i];
|
|
}
|
|
if (((high !=1)||(low !=0))){ //allow only 1s and 0s
|
|
// PrintAndLog("no data found");
|
|
return 0;
|
|
}
|
|
uint8_t parityTest=0;
|
|
// 111111111 bit pattern represent start of frame
|
|
uint8_t frame_marker_mask[] = {1,1,1,1,1,1,1,1,1};
|
|
uint32_t idx = 0;
|
|
uint32_t ii=0;
|
|
uint8_t resetCnt = 0;
|
|
while( (idx + 64) < size) {
|
|
restart:
|
|
// search for a start of frame marker
|
|
if ( memcmp(BitStream+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
|
|
{ // frame marker found
|
|
idx+=9;
|
|
for (i=0; i<10;i++){
|
|
for(ii=0; ii<5; ++ii){
|
|
parityTest += BitStream[(i*5)+ii+idx];
|
|
}
|
|
if (parityTest== ((parityTest>>1)<<1)){
|
|
parityTest=0;
|
|
for (ii=0; ii<4;++ii){
|
|
lo=(lo<<1LL)|(BitStream[(i*5)+ii+idx]);
|
|
}
|
|
//PrintAndLog("DEBUG: EM parity passed parity val: %d, i:%d, ii:%d,idx:%d, Buffer: %d%d%d%d%d,lo: %d",parityTest,i,ii,idx,BitStream[idx+ii+(i*5)-5],BitStream[idx+ii+(i*5)-4],BitStream[idx+ii+(i*5)-3],BitStream[idx+ii+(i*5)-2],BitStream[idx+ii+(i*5)-1],lo);
|
|
}else {//parity failed
|
|
//PrintAndLog("DEBUG: EM parity failed parity val: %d, i:%d, ii:%d,idx:%d, Buffer: %d%d%d%d%d",parityTest,i,ii,idx,BitStream[idx+ii+(i*5)-5],BitStream[idx+ii+(i*5)-4],BitStream[idx+ii+(i*5)-3],BitStream[idx+ii+(i*5)-2],BitStream[idx+ii+(i*5)-1]);
|
|
parityTest=0;
|
|
idx-=8;
|
|
if (resetCnt>5)return 0;
|
|
resetCnt++;
|
|
goto restart;//continue;
|
|
}
|
|
}
|
|
//skip last 5 bit parity test for simplicity.
|
|
return lo;
|
|
}else{
|
|
idx++;
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
//by marshmellow
|
|
//takes 2 arguments - clock and invert both as integers
|
|
//attempts to demodulate ask while decoding manchester
|
|
//prints binary found and saves in graphbuffer for further commands
|
|
int askmandemod(uint8_t *BinStream, size_t *size, int *clk, int *invert)
|
|
{
|
|
int i;
|
|
int high = 0, low = 128;
|
|
*clk=DetectASKClock(BinStream, *size, *clk); //clock default
|
|
|
|
if (*clk<8) *clk =64;
|
|
if (*clk<32) *clk=32;
|
|
if (*invert != 0 && *invert != 1) *invert=0;
|
|
uint32_t initLoopMax = 200;
|
|
if (initLoopMax > *size) initLoopMax=*size;
|
|
// Detect high and lows
|
|
for (i = 0; i < initLoopMax; ++i) //200 samples should be enough to find high and low values
|
|
{
|
|
if (BinStream[i] > high)
|
|
high = BinStream[i];
|
|
else if (BinStream[i] < low)
|
|
low = BinStream[i];
|
|
}
|
|
if ((high < 158) ){ //throw away static
|
|
//PrintAndLog("no data found");
|
|
return -2;
|
|
}
|
|
//25% fuzz in case highs and lows aren't clipped [marshmellow]
|
|
high=(int)(((high-128)*.75)+128);
|
|
low= (int)(((low-128)*.75)+128);
|
|
|
|
//PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
|
|
int lastBit = 0; //set first clock check
|
|
uint32_t bitnum = 0; //output counter
|
|
int tol = 0; //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave
|
|
if (*clk==32)tol=1; //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely
|
|
int iii = 0;
|
|
uint32_t gLen = *size;
|
|
if (gLen > 3000) gLen=3000;
|
|
uint8_t errCnt =0;
|
|
uint32_t bestStart = *size;
|
|
uint32_t bestErrCnt = (*size/1000);
|
|
uint32_t maxErr = (*size/1000);
|
|
//PrintAndLog("DEBUG - lastbit - %d",lastBit);
|
|
//loop to find first wave that works
|
|
for (iii=0; iii < gLen; ++iii){
|
|
if ((BinStream[iii] >= high) || (BinStream[iii] <= low)){
|
|
lastBit=iii-*clk;
|
|
errCnt=0;
|
|
//loop through to see if this start location works
|
|
for (i = iii; i < *size; ++i) {
|
|
if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){
|
|
lastBit+=*clk;
|
|
} else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){
|
|
//low found and we are expecting a bar
|
|
lastBit+=*clk;
|
|
} else {
|
|
//mid value found or no bar supposed to be here
|
|
if ((i-lastBit)>(*clk+tol)){
|
|
//should have hit a high or low based on clock!!
|
|
|
|
//debug
|
|
//PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
|
|
|
|
errCnt++;
|
|
lastBit+=*clk;//skip over until hit too many errors
|
|
if (errCnt>(maxErr)) break; //allow 1 error for every 1000 samples else start over
|
|
}
|
|
}
|
|
if ((i-iii) >(400 * *clk)) break; //got plenty of bits
|
|
}
|
|
//we got more than 64 good bits and not all errors
|
|
if ((((i-iii)/ *clk) > (64+errCnt)) && (errCnt<maxErr)) {
|
|
//possible good read
|
|
if (errCnt==0){
|
|
bestStart=iii;
|
|
bestErrCnt=errCnt;
|
|
break; //great read - finish
|
|
}
|
|
if (errCnt<bestErrCnt){ //set this as new best run
|
|
bestErrCnt=errCnt;
|
|
bestStart = iii;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if (bestErrCnt<maxErr){
|
|
//best run is good enough set to best run and set overwrite BinStream
|
|
iii=bestStart;
|
|
lastBit = bestStart - *clk;
|
|
bitnum=0;
|
|
for (i = iii; i < *size; ++i) {
|
|
if ((BinStream[i] >= high) && ((i-lastBit) > (*clk-tol))){
|
|
lastBit += *clk;
|
|
BinStream[bitnum] = *invert;
|
|
bitnum++;
|
|
} else if ((BinStream[i] <= low) && ((i-lastBit) > (*clk-tol))){
|
|
//low found and we are expecting a bar
|
|
lastBit+=*clk;
|
|
BinStream[bitnum] = 1-*invert;
|
|
bitnum++;
|
|
} else {
|
|
//mid value found or no bar supposed to be here
|
|
if ((i-lastBit)>(*clk+tol)){
|
|
//should have hit a high or low based on clock!!
|
|
|
|
//debug
|
|
//PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
|
|
if (bitnum > 0){
|
|
BinStream[bitnum]=77;
|
|
bitnum++;
|
|
}
|
|
|
|
lastBit+=*clk;//skip over error
|
|
}
|
|
}
|
|
if (bitnum >=400) break;
|
|
}
|
|
*size=bitnum;
|
|
} else{
|
|
*invert=bestStart;
|
|
*clk=iii;
|
|
return -1;
|
|
}
|
|
return bestErrCnt;
|
|
}
|
|
|
|
//by marshmellow
|
|
//take 10 and 01 and manchester decode
|
|
//run through 2 times and take least errCnt
|
|
int manrawdecode(uint8_t * BitStream, size_t *size)
|
|
{
|
|
int bitnum=0;
|
|
int errCnt =0;
|
|
int i=1;
|
|
int bestErr = 1000;
|
|
int bestRun = 0;
|
|
int ii=1;
|
|
for (ii=1;ii<3;++ii){
|
|
i=1;
|
|
for (i=i+ii;i<*size-2;i+=2){
|
|
if(BitStream[i]==1 && (BitStream[i+1]==0)){
|
|
} else if((BitStream[i]==0)&& BitStream[i+1]==1){
|
|
} else {
|
|
errCnt++;
|
|
}
|
|
if(bitnum>300) break;
|
|
}
|
|
if (bestErr>errCnt){
|
|
bestErr=errCnt;
|
|
bestRun=ii;
|
|
}
|
|
errCnt=0;
|
|
}
|
|
errCnt=bestErr;
|
|
if (errCnt<20){
|
|
ii=bestRun;
|
|
i=1;
|
|
for (i=i+ii;i < *size-2;i+=2){
|
|
if(BitStream[i] == 1 && (BitStream[i+1] == 0)){
|
|
BitStream[bitnum++]=0;
|
|
} else if((BitStream[i] == 0) && BitStream[i+1] == 1){
|
|
BitStream[bitnum++]=1;
|
|
} else {
|
|
BitStream[bitnum++]=77;
|
|
//errCnt++;
|
|
}
|
|
if(bitnum>300) break;
|
|
}
|
|
*size=bitnum;
|
|
}
|
|
return errCnt;
|
|
}
|
|
|
|
|
|
//by marshmellow
|
|
//take 01 or 10 = 0 and 11 or 00 = 1
|
|
int BiphaseRawDecode(uint8_t *BitStream, size_t *size, int offset)
|
|
{
|
|
uint8_t bitnum=0;
|
|
uint32_t errCnt =0;
|
|
uint32_t i=1;
|
|
i=offset;
|
|
for (;i<*size-2;i+=2){
|
|
if((BitStream[i]==1 && BitStream[i+1]==0) || (BitStream[i]==0 && BitStream[i+1]==1)){
|
|
BitStream[bitnum++]=1;
|
|
} else if((BitStream[i]==0 && BitStream[i+1]==0) || (BitStream[i]==1 && BitStream[i+1]==1)){
|
|
BitStream[bitnum++]=0;
|
|
} else {
|
|
BitStream[bitnum++]=77;
|
|
errCnt++;
|
|
}
|
|
if(bitnum>250) break;
|
|
}
|
|
*size=bitnum;
|
|
return errCnt;
|
|
}
|
|
|
|
//by marshmellow
|
|
//takes 2 arguments - clock and invert both as integers
|
|
//attempts to demodulate ask only
|
|
//prints binary found and saves in graphbuffer for further commands
|
|
int askrawdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert)
|
|
{
|
|
uint32_t i;
|
|
// int invert=0; //invert default
|
|
int high = 0, low = 128;
|
|
*clk=DetectASKClock(BinStream, *size, *clk); //clock default
|
|
uint8_t BitStream[502] = {0};
|
|
|
|
if (*clk<8) *clk =64;
|
|
if (*clk<32) *clk=32;
|
|
if (*invert != 0 && *invert != 1) *invert =0;
|
|
uint32_t initLoopMax = 200;
|
|
if (initLoopMax > *size) initLoopMax=*size;
|
|
// Detect high and lows
|
|
for (i = 0; i < initLoopMax; ++i) //200 samples should be plenty to find high and low values
|
|
{
|
|
if (BinStream[i] > high)
|
|
high = BinStream[i];
|
|
else if (BinStream[i] < low)
|
|
low = BinStream[i];
|
|
}
|
|
if ((high < 158)){ //throw away static
|
|
// PrintAndLog("no data found");
|
|
return -2;
|
|
}
|
|
//25% fuzz in case highs and lows aren't clipped [marshmellow]
|
|
high=(int)(((high-128)*.75)+128);
|
|
low= (int)(((low-128)*.75)+128);
|
|
|
|
//PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
|
|
int lastBit = 0; //set first clock check
|
|
uint32_t bitnum = 0; //output counter
|
|
uint8_t tol = 0; //clock tolerance adjust - waves will be accepted as within the clock
|
|
// if they fall + or - this value + clock from last valid wave
|
|
if (*clk == 32) tol=1; //clock tolerance may not be needed anymore currently set to
|
|
// + or - 1 but could be increased for poor waves or removed entirely
|
|
uint32_t iii = 0;
|
|
uint32_t gLen = *size;
|
|
if (gLen > 500) gLen=500;
|
|
uint8_t errCnt =0;
|
|
uint32_t bestStart = *size;
|
|
uint32_t bestErrCnt = (*size/1000);
|
|
uint8_t midBit=0;
|
|
//PrintAndLog("DEBUG - lastbit - %d",lastBit);
|
|
//loop to find first wave that works
|
|
for (iii=0; iii < gLen; ++iii){
|
|
if ((BinStream[iii]>=high) || (BinStream[iii]<=low)){
|
|
lastBit=iii-*clk;
|
|
//loop through to see if this start location works
|
|
for (i = iii; i < *size; ++i) {
|
|
if ((BinStream[i] >= high) && ((i-lastBit)>(*clk-tol))){
|
|
lastBit+=*clk;
|
|
BitStream[bitnum] = *invert;
|
|
bitnum++;
|
|
midBit=0;
|
|
} else if ((BinStream[i] <= low) && ((i-lastBit)>(*clk-tol))){
|
|
//low found and we are expecting a bar
|
|
lastBit+=*clk;
|
|
BitStream[bitnum] = 1- *invert;
|
|
bitnum++;
|
|
midBit=0;
|
|
} else if ((BinStream[i]<=low) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
|
|
//mid bar?
|
|
midBit=1;
|
|
BitStream[bitnum]= 1- *invert;
|
|
bitnum++;
|
|
} else if ((BinStream[i]>=high) && (midBit==0) && ((i-lastBit)>((*clk/2)-tol))){
|
|
//mid bar?
|
|
midBit=1;
|
|
BitStream[bitnum]= *invert;
|
|
bitnum++;
|
|
} else if ((i-lastBit)>((*clk/2)+tol) && (midBit==0)){
|
|
//no mid bar found
|
|
midBit=1;
|
|
BitStream[bitnum]= BitStream[bitnum-1];
|
|
bitnum++;
|
|
} else {
|
|
//mid value found or no bar supposed to be here
|
|
|
|
if ((i-lastBit)>(*clk+tol)){
|
|
//should have hit a high or low based on clock!!
|
|
//debug
|
|
//PrintAndLog("DEBUG - no wave in expected area - location: %d, expected: %d-%d, lastBit: %d - resetting search",i,(lastBit+(clk-((int)(tol)))),(lastBit+(clk+((int)(tol)))),lastBit);
|
|
if (bitnum > 0){
|
|
BitStream[bitnum]=77;
|
|
bitnum++;
|
|
}
|
|
|
|
errCnt++;
|
|
lastBit+=*clk;//skip over until hit too many errors
|
|
if (errCnt > ((*size/1000))){ //allow 1 error for every 1000 samples else start over
|
|
errCnt=0;
|
|
bitnum=0;//start over
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if (bitnum>500) break;
|
|
}
|
|
//we got more than 64 good bits and not all errors
|
|
if ((bitnum > (64+errCnt)) && (errCnt<(*size/1000))) {
|
|
//possible good read
|
|
if (errCnt==0) break; //great read - finish
|
|
if (bestStart == iii) break; //if current run == bestErrCnt run (after exhausted testing) then finish
|
|
if (errCnt<bestErrCnt){ //set this as new best run
|
|
bestErrCnt=errCnt;
|
|
bestStart = iii;
|
|
}
|
|
}
|
|
}
|
|
if (iii>=gLen){ //exhausted test
|
|
//if there was a ok test go back to that one and re-run the best run (then dump after that run)
|
|
if (bestErrCnt < (*size/1000)) iii=bestStart;
|
|
}
|
|
}
|
|
if (bitnum>16){
|
|
for (i=0; i < bitnum; ++i){
|
|
BinStream[i]=BitStream[i];
|
|
}
|
|
*size=bitnum;
|
|
} else return -1;
|
|
return errCnt;
|
|
}
|
|
//translate wave to 11111100000 (1 for each short wave 0 for each long wave)
|
|
size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow)
|
|
{
|
|
uint32_t last_transition = 0;
|
|
uint32_t idx = 1;
|
|
uint32_t maxVal=0;
|
|
if (fchigh==0) fchigh=10;
|
|
if (fclow==0) fclow=8;
|
|
// we do care about the actual theshold value as sometimes near the center of the
|
|
// wave we may get static that changes direction of wave for one value
|
|
// if our value is too low it might affect the read. and if our tag or
|
|
// antenna is weak a setting too high might not see anything. [marshmellow]
|
|
if (size<100) return 0;
|
|
for(idx=1; idx<100; idx++){
|
|
if(maxVal<dest[idx]) maxVal = dest[idx];
|
|
}
|
|
// set close to the top of the wave threshold with 25% margin for error
|
|
// less likely to get a false transition up there.
|
|
// (but have to be careful not to go too high and miss some short waves)
|
|
uint8_t threshold_value = (uint8_t)(((maxVal-128)*.75)+128);
|
|
|
|
// sync to first lo-hi transition, and threshold
|
|
|
|
// Need to threshold first sample
|
|
|
|
if(dest[0] < threshold_value) dest[0] = 0;
|
|
else dest[0] = 1;
|
|
|
|
size_t numBits = 0;
|
|
// count cycles between consecutive lo-hi transitions, there should be either 8 (fc/8)
|
|
// or 10 (fc/10) cycles but in practice due to noise etc we may end up with with anywhere
|
|
// between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
|
|
for(idx = 1; idx < size; idx++) {
|
|
// threshold current value
|
|
|
|
if (dest[idx] < threshold_value) dest[idx] = 0;
|
|
else dest[idx] = 1;
|
|
|
|
// Check for 0->1 transition
|
|
if (dest[idx-1] < dest[idx]) { // 0 -> 1 transition
|
|
if ((idx-last_transition)<(fclow-2)){ //0-5 = garbage noise
|
|
//do nothing with extra garbage
|
|
} else if ((idx-last_transition) < (fchigh-1)) { //6-8 = 8 waves
|
|
dest[numBits]=1;
|
|
} else { //9+ = 10 waves
|
|
dest[numBits]=0;
|
|
}
|
|
last_transition = idx;
|
|
numBits++;
|
|
}
|
|
}
|
|
return numBits; //Actually, it returns the number of bytes, but each byte represents a bit: 1 or 0
|
|
}
|
|
|
|
uint32_t myround2(float f)
|
|
{
|
|
if (f >= 2000) return 2000;//something bad happened
|
|
return (uint32_t) (f + (float)0.5);
|
|
}
|
|
|
|
//translate 11111100000 to 10
|
|
size_t aggregate_bits(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t maxConsequtiveBits,
|
|
uint8_t invert, uint8_t fchigh, uint8_t fclow)
|
|
{
|
|
uint8_t lastval=dest[0];
|
|
uint32_t idx=0;
|
|
size_t numBits=0;
|
|
uint32_t n=1;
|
|
|
|
for( idx=1; idx < size; idx++) {
|
|
|
|
if (dest[idx]==lastval) {
|
|
n++;
|
|
continue;
|
|
}
|
|
//if lastval was 1, we have a 1->0 crossing
|
|
if ( dest[idx-1]==1 ) {
|
|
n=myround2((float)(n+1)/((float)(rfLen)/(float)fclow));
|
|
} else {// 0->1 crossing
|
|
n=myround2((float)(n+1)/((float)(rfLen-2)/(float)fchigh)); //-2 for fudge factor
|
|
}
|
|
if (n == 0) n = 1;
|
|
|
|
if(n < maxConsequtiveBits) //Consecutive
|
|
{
|
|
if(invert==0){ //invert bits
|
|
memset(dest+numBits, dest[idx-1] , n);
|
|
}else{
|
|
memset(dest+numBits, dest[idx-1]^1 , n);
|
|
}
|
|
numBits += n;
|
|
}
|
|
n=0;
|
|
lastval=dest[idx];
|
|
}//end for
|
|
return numBits;
|
|
}
|
|
//by marshmellow (from holiman's base)
|
|
// full fsk demod from GraphBuffer wave to decoded 1s and 0s (no mandemod)
|
|
int fskdemod(uint8_t *dest, size_t size, uint8_t rfLen, uint8_t invert, uint8_t fchigh, uint8_t fclow)
|
|
{
|
|
// FSK demodulator
|
|
size = fsk_wave_demod(dest, size, fchigh, fclow);
|
|
size = aggregate_bits(dest, size, rfLen, 192, invert, fchigh, fclow);
|
|
return size;
|
|
}
|
|
// loop to get raw HID waveform then FSK demodulate the TAG ID from it
|
|
int HIDdemodFSK(uint8_t *dest, size_t size, uint32_t *hi2, uint32_t *hi, uint32_t *lo)
|
|
{
|
|
|
|
size_t idx=0; //, found=0; //size=0,
|
|
// FSK demodulator
|
|
size = fskdemod(dest, size,50,0,10,8);
|
|
|
|
// final loop, go over previously decoded manchester data and decode into usable tag ID
|
|
// 111000 bit pattern represent start of frame, 01 pattern represents a 1 and 10 represents a 0
|
|
uint8_t frame_marker_mask[] = {1,1,1,0,0,0};
|
|
int numshifts = 0;
|
|
idx = 0;
|
|
//one scan
|
|
while( idx + sizeof(frame_marker_mask) < size) {
|
|
// search for a start of frame marker
|
|
if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
|
|
{ // frame marker found
|
|
idx+=sizeof(frame_marker_mask);
|
|
while(dest[idx] != dest[idx+1] && idx < size-2)
|
|
{
|
|
// Keep going until next frame marker (or error)
|
|
// Shift in a bit. Start by shifting high registers
|
|
*hi2 = (*hi2<<1)|(*hi>>31);
|
|
*hi = (*hi<<1)|(*lo>>31);
|
|
//Then, shift in a 0 or one into low
|
|
if (dest[idx] && !dest[idx+1]) // 1 0
|
|
*lo=(*lo<<1)|0;
|
|
else // 0 1
|
|
*lo=(*lo<<1)|1;
|
|
numshifts++;
|
|
idx += 2;
|
|
}
|
|
// Hopefully, we read a tag and hit upon the next frame marker
|
|
if(idx + sizeof(frame_marker_mask) < size)
|
|
{
|
|
if ( memcmp(dest+idx, frame_marker_mask, sizeof(frame_marker_mask)) == 0)
|
|
{
|
|
//good return
|
|
return idx;
|
|
}
|
|
}
|
|
// reset
|
|
*hi2 = *hi = *lo = 0;
|
|
numshifts = 0;
|
|
}else {
|
|
idx++;
|
|
}
|
|
}
|
|
return -1;
|
|
}
|
|
|
|
uint32_t bytebits_to_byte(uint8_t* src, size_t numbits)
|
|
{
|
|
uint32_t num = 0;
|
|
for(int i = 0 ; i < numbits ; i++)
|
|
{
|
|
num = (num << 1) | (*src);
|
|
src++;
|
|
}
|
|
return num;
|
|
}
|
|
|
|
int IOdemodFSK(uint8_t *dest, size_t size)
|
|
{
|
|
static const uint8_t THRESHOLD = 140;
|
|
uint32_t idx=0;
|
|
//make sure buffer has data
|
|
if (size < 66) return -1;
|
|
//test samples are not just noise
|
|
uint8_t justNoise = 1;
|
|
for(idx=0;idx< size && justNoise ;idx++){
|
|
justNoise = dest[idx] < THRESHOLD;
|
|
}
|
|
if(justNoise) return 0;
|
|
|
|
// FSK demodulator
|
|
size = fskdemod(dest, size, 64, 1, 10, 8); // RF/64 and invert
|
|
if (size < 65) return -1; //did we get a good demod?
|
|
//Index map
|
|
//0 10 20 30 40 50 60
|
|
//| | | | | | |
|
|
//01234567 8 90123456 7 89012345 6 78901234 5 67890123 4 56789012 3 45678901 23
|
|
//-----------------------------------------------------------------------------
|
|
//00000000 0 11110000 1 facility 1 version* 1 code*one 1 code*two 1 ???????? 11
|
|
//
|
|
//XSF(version)facility:codeone+codetwo
|
|
//Handle the data
|
|
uint8_t mask[] = {0,0,0,0,0,0,0,0,0,1};
|
|
for( idx=0; idx < (size - 65); idx++) {
|
|
if ( memcmp(dest + idx, mask, sizeof(mask))==0) {
|
|
//frame marker found
|
|
if (!dest[idx+8] && dest[idx+17]==1 && dest[idx+26]==1 && dest[idx+35]==1 && dest[idx+44]==1 && dest[idx+53]==1){
|
|
//confirmed proper separator bits found
|
|
//return start position
|
|
return (int) idx;
|
|
}
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
// by marshmellow
|
|
// not perfect especially with lower clocks or VERY good antennas (heavy wave clipping)
|
|
// maybe somehow adjust peak trimming value based on samples to fix?
|
|
int DetectASKClock(uint8_t dest[], size_t size, int clock)
|
|
{
|
|
int i=0;
|
|
int peak=0;
|
|
int low=128;
|
|
int clk[]={16,32,40,50,64,100,128,256};
|
|
int loopCnt = 256; //don't need to loop through entire array...
|
|
if (size<loopCnt) loopCnt = size;
|
|
|
|
//if we already have a valid clock quit
|
|
for (;i<8;++i)
|
|
if (clk[i] == clock) return clock;
|
|
|
|
//get high and low peak
|
|
for (i=0; i < loopCnt; ++i){
|
|
if(dest[i] > peak){
|
|
peak = dest[i];
|
|
}
|
|
if(dest[i] < low){
|
|
low = dest[i];
|
|
}
|
|
}
|
|
peak=(int)(((peak-128)*.75)+128);
|
|
low= (int)(((low-128)*.75)+128);
|
|
int ii;
|
|
int clkCnt;
|
|
int tol = 0;
|
|
int bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000};
|
|
int errCnt=0;
|
|
//test each valid clock from smallest to greatest to see which lines up
|
|
for(clkCnt=0; clkCnt < 6; ++clkCnt){
|
|
if (clk[clkCnt] == 32){
|
|
tol=1;
|
|
}else{
|
|
tol=0;
|
|
}
|
|
bestErr[clkCnt]=1000;
|
|
//try lining up the peaks by moving starting point (try first 256)
|
|
for (ii=0; ii< loopCnt; ++ii){
|
|
if ((dest[ii] >= peak) || (dest[ii] <= low)){
|
|
errCnt=0;
|
|
// now that we have the first one lined up test rest of wave array
|
|
for (i=0; i<((int)(size/clk[clkCnt])-1); ++i){
|
|
if (dest[ii+(i*clk[clkCnt])]>=peak || dest[ii+(i*clk[clkCnt])]<=low){
|
|
}else if(dest[ii+(i*clk[clkCnt])-tol]>=peak || dest[ii+(i*clk[clkCnt])-tol]<=low){
|
|
}else if(dest[ii+(i*clk[clkCnt])+tol]>=peak || dest[ii+(i*clk[clkCnt])+tol]<=low){
|
|
}else{ //error no peak detected
|
|
errCnt++;
|
|
}
|
|
}
|
|
//if we found no errors this is correct one - return this clock
|
|
if(errCnt==0) return clk[clkCnt];
|
|
//if we found errors see if it is lowest so far and save it as best run
|
|
if(errCnt<bestErr[clkCnt]) bestErr[clkCnt]=errCnt;
|
|
}
|
|
}
|
|
}
|
|
int iii=0;
|
|
int best=0;
|
|
for (iii=0; iii<7;++iii){
|
|
if (bestErr[iii]<bestErr[best]){
|
|
// current best bit to error ratio vs new bit to error ratio
|
|
if (((size/clk[best])/bestErr[best] < (size/clk[iii])/bestErr[iii]) ){
|
|
best = iii;
|
|
}
|
|
}
|
|
}
|
|
return clk[best];
|
|
}
|
|
|
|
//by marshmellow
|
|
//detect psk clock by reading #peaks vs no peaks(or errors)
|
|
int DetectpskNRZClock(uint8_t dest[], size_t size, int clock)
|
|
{
|
|
int i=0;
|
|
int peak=0;
|
|
int low=128;
|
|
int clk[]={16,32,40,50,64,100,128,256};
|
|
int loopCnt = 2048; //don't need to loop through entire array...
|
|
if (size<loopCnt) loopCnt = size;
|
|
|
|
//if we already have a valid clock quit
|
|
for (; i < 8; ++i)
|
|
if (clk[i] == clock) return clock;
|
|
|
|
//get high and low peak
|
|
for (i=0; i < loopCnt; ++i){
|
|
if(dest[i] > peak){
|
|
peak = dest[i];
|
|
}
|
|
if(dest[i] < low){
|
|
low = dest[i];
|
|
}
|
|
}
|
|
peak=(int)(((peak-128)*.90)+128);
|
|
low= (int)(((low-128)*.90)+128);
|
|
//PrintAndLog("DEBUG: peak: %d, low: %d",peak,low);
|
|
int ii;
|
|
uint8_t clkCnt;
|
|
uint8_t tol = 0;
|
|
int peakcnt=0;
|
|
int errCnt=0;
|
|
int bestErr[]={1000,1000,1000,1000,1000,1000,1000,1000,1000};
|
|
int peaksdet[]={0,0,0,0,0,0,0,0,0};
|
|
//test each valid clock from smallest to greatest to see which lines up
|
|
for(clkCnt=0; clkCnt < 6; ++clkCnt){
|
|
if (clk[clkCnt] == 32){
|
|
tol=0;
|
|
}else{
|
|
tol=0;
|
|
}
|
|
//try lining up the peaks by moving starting point (try first 256)
|
|
for (ii=0; ii< loopCnt; ++ii){
|
|
if ((dest[ii] >= peak) || (dest[ii] <= low)){
|
|
errCnt=0;
|
|
peakcnt=0;
|
|
// now that we have the first one lined up test rest of wave array
|
|
for (i=0; i < ((int)(size/clk[clkCnt])-1); ++i){
|
|
if (dest[ii+(i*clk[clkCnt])]>=peak || dest[ii+(i*clk[clkCnt])]<=low){
|
|
peakcnt++;
|
|
}else if(dest[ii+(i*clk[clkCnt])-tol]>=peak || dest[ii+(i*clk[clkCnt])-tol]<=low){
|
|
peakcnt++;
|
|
}else if(dest[ii+(i*clk[clkCnt])+tol]>=peak || dest[ii+(i*clk[clkCnt])+tol]<=low){
|
|
peakcnt++;
|
|
}else{ //error no peak detected
|
|
errCnt++;
|
|
}
|
|
}
|
|
if(peakcnt>peaksdet[clkCnt]) {
|
|
peaksdet[clkCnt]=peakcnt;
|
|
bestErr[clkCnt]=errCnt;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
int iii=0;
|
|
int best=0;
|
|
//int ratio2; //debug
|
|
int ratio;
|
|
//int bits;
|
|
for (iii=0; iii < 7; ++iii){
|
|
ratio=1000;
|
|
//ratio2=1000; //debug
|
|
//bits=size/clk[iii]; //debug
|
|
if (peaksdet[iii] > 0){
|
|
ratio=bestErr[iii]/peaksdet[iii];
|
|
if (((bestErr[best]/peaksdet[best]) > (ratio)+1)){
|
|
best = iii;
|
|
}
|
|
//ratio2=bits/peaksdet[iii]; //debug
|
|
}
|
|
//PrintAndLog("DEBUG: Clk: %d, peaks: %d, errs: %d, bestClk: %d, ratio: %d, bits: %d, peakbitr: %d",clk[iii],peaksdet[iii],bestErr[iii],clk[best],ratio, bits,ratio2);
|
|
}
|
|
return clk[best];
|
|
}
|
|
|
|
//by marshmellow (attempt to get rid of high immediately after a low)
|
|
void pskCleanWave(uint8_t *bitStream, size_t size)
|
|
{
|
|
int i;
|
|
int low=128;
|
|
int high=0;
|
|
int gap = 4;
|
|
// int loopMax = 2048;
|
|
int newLow=0;
|
|
int newHigh=0;
|
|
for (i=0; i < size; ++i){
|
|
if (bitStream[i] < low) low=bitStream[i];
|
|
if (bitStream[i] > high) high=bitStream[i];
|
|
}
|
|
high = (int)(((high-128)*.80)+128);
|
|
low = (int)(((low-128)*.90)+128);
|
|
//low = (uint8_t)(((int)(low)-128)*.80)+128;
|
|
for (i=0; i < size; ++i){
|
|
if (newLow == 1){
|
|
bitStream[i]=low+8;
|
|
gap--;
|
|
if (gap == 0){
|
|
newLow=0;
|
|
gap=4;
|
|
}
|
|
}else if (newHigh == 1){
|
|
bitStream[i]=high-8;
|
|
gap--;
|
|
if (gap == 0){
|
|
newHigh=0;
|
|
gap=4;
|
|
}
|
|
}
|
|
if (bitStream[i] <= low) newLow=1;
|
|
if (bitStream[i] >= high) newHigh=1;
|
|
}
|
|
return;
|
|
}
|
|
|
|
|
|
//redesigned by marshmellow adjusted from existing decode functions
|
|
//indala id decoding - only tested on 26 bit tags, but attempted to make it work for more
|
|
int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert)
|
|
{
|
|
//26 bit 40134 format (don't know other formats)
|
|
int i;
|
|
int long_wait;
|
|
long_wait = 29;//29 leading zeros in format
|
|
int start;
|
|
int first = 0;
|
|
int first2 = 0;
|
|
int bitCnt = 0;
|
|
int ii;
|
|
// Finding the start of a UID
|
|
for (start = 0; start <= *size - 250; start++) {
|
|
first = bitStream[start];
|
|
for (i = start; i < start + long_wait; i++) {
|
|
if (bitStream[i] != first) {
|
|
break;
|
|
}
|
|
}
|
|
if (i == (start + long_wait)) {
|
|
break;
|
|
}
|
|
}
|
|
if (start == *size - 250 + 1) {
|
|
// did not find start sequence
|
|
return -1;
|
|
}
|
|
//found start once now test length by finding next one
|
|
// Inverting signal if needed
|
|
if (first == 1) {
|
|
for (i = start; i < *size; i++) {
|
|
bitStream[i] = !bitStream[i];
|
|
}
|
|
*invert = 1;
|
|
}else *invert=0;
|
|
|
|
int iii;
|
|
for (ii=start+29; ii <= *size - 250; ii++) {
|
|
first2 = bitStream[ii];
|
|
for (iii = ii; iii < ii + long_wait; iii++) {
|
|
if (bitStream[iii] != first2) {
|
|
break;
|
|
}
|
|
}
|
|
if (iii == (ii + long_wait)) {
|
|
break;
|
|
}
|
|
}
|
|
if (ii== *size - 250 + 1){
|
|
// did not find second start sequence
|
|
return -2;
|
|
}
|
|
bitCnt=ii-start;
|
|
|
|
// Dumping UID
|
|
i = start;
|
|
for (ii = 0; ii < bitCnt; ii++) {
|
|
bitStream[ii] = bitStream[i++];
|
|
}
|
|
*size=bitCnt;
|
|
return 1;
|
|
}
|
|
|
|
|
|
//by marshmellow - demodulate PSK wave or NRZ wave (both similar enough)
|
|
//peaks switch bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
|
|
int pskNRZrawDemod(uint8_t *dest, size_t *size, int *clk, int *invert)
|
|
{
|
|
pskCleanWave(dest,*size);
|
|
int clk2 = DetectpskNRZClock(dest, *size, *clk);
|
|
*clk=clk2;
|
|
uint32_t i;
|
|
uint8_t high=0, low=128;
|
|
uint32_t gLen = *size;
|
|
if (gLen > 1280) gLen=1280;
|
|
// get high
|
|
for (i=0; i < gLen; ++i){
|
|
if (dest[i] > high) high = dest[i];
|
|
if (dest[i] < low) low = dest[i];
|
|
}
|
|
//fudge high/low bars by 25%
|
|
high = (uint8_t)((((int)(high)-128)*.75)+128);
|
|
low = (uint8_t)((((int)(low)-128)*.80)+128);
|
|
|
|
//PrintAndLog("DEBUG - valid high: %d - valid low: %d",high,low);
|
|
int lastBit = 0; //set first clock check
|
|
uint32_t bitnum = 0; //output counter
|
|
uint8_t tol = 0; //clock tolerance adjust - waves will be accepted as within the clock if they fall + or - this value + clock from last valid wave
|
|
if (*clk==32)tol=2; //clock tolerance may not be needed anymore currently set to + or - 1 but could be increased for poor waves or removed entirely
|
|
uint32_t iii = 0;
|
|
uint8_t errCnt =0;
|
|
uint32_t bestStart = *size;
|
|
uint32_t maxErr = (*size/1000);
|
|
uint32_t bestErrCnt = maxErr;
|
|
//uint8_t midBit=0;
|
|
uint8_t curBit=0;
|
|
uint8_t bitHigh=0;
|
|
uint8_t ignorewin=*clk/8;
|
|
//PrintAndLog("DEBUG - lastbit - %d",lastBit);
|
|
//loop to find first wave that works - align to clock
|
|
for (iii=0; iii < gLen; ++iii){
|
|
if ((dest[iii]>=high) || (dest[iii]<=low)){
|
|
lastBit=iii-*clk;
|
|
//loop through to see if this start location works
|
|
for (i = iii; i < *size; ++i) {
|
|
//if we found a high bar and we are at a clock bit
|
|
if ((dest[i]>=high ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
|
|
bitHigh=1;
|
|
lastBit+=*clk;
|
|
ignorewin=*clk/8;
|
|
bitnum++;
|
|
//else if low bar found and we are at a clock point
|
|
}else if ((dest[i]<=low ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
|
|
bitHigh=1;
|
|
lastBit+=*clk;
|
|
ignorewin=*clk/8;
|
|
bitnum++;
|
|
//else if no bars found
|
|
}else if(dest[i] < high && dest[i] > low) {
|
|
if (ignorewin==0){
|
|
bitHigh=0;
|
|
}else ignorewin--;
|
|
//if we are past a clock point
|
|
if (i >= lastBit+*clk+tol){ //clock val
|
|
lastBit+=*clk;
|
|
bitnum++;
|
|
}
|
|
//else if bar found but we are not at a clock bit and we did not just have a clock bit
|
|
}else if ((dest[i]>=high || dest[i]<=low) && (i<lastBit+*clk-tol || i>lastBit+*clk+tol) && (bitHigh==0)){
|
|
//error bar found no clock...
|
|
errCnt++;
|
|
}
|
|
if (bitnum>=1000) break;
|
|
}
|
|
//we got more than 64 good bits and not all errors
|
|
if ((bitnum > (64+errCnt)) && (errCnt < (maxErr))) {
|
|
//possible good read
|
|
if (errCnt == 0){
|
|
bestStart = iii;
|
|
bestErrCnt = errCnt;
|
|
break; //great read - finish
|
|
}
|
|
if (bestStart == iii) break; //if current run == bestErrCnt run (after exhausted testing) then finish
|
|
if (errCnt < bestErrCnt){ //set this as new best run
|
|
bestErrCnt = errCnt;
|
|
bestStart = iii;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
if (bestErrCnt < maxErr){
|
|
//best run is good enough set to best run and set overwrite BinStream
|
|
iii=bestStart;
|
|
lastBit=bestStart-*clk;
|
|
bitnum=0;
|
|
for (i = iii; i < *size; ++i) {
|
|
//if we found a high bar and we are at a clock bit
|
|
if ((dest[i] >= high ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
|
|
bitHigh=1;
|
|
lastBit+=*clk;
|
|
curBit=1-*invert;
|
|
dest[bitnum]=curBit;
|
|
ignorewin=*clk/8;
|
|
bitnum++;
|
|
//else if low bar found and we are at a clock point
|
|
}else if ((dest[i]<=low ) && (i>=lastBit+*clk-tol && i<=lastBit+*clk+tol)){
|
|
bitHigh=1;
|
|
lastBit+=*clk;
|
|
curBit=*invert;
|
|
dest[bitnum]=curBit;
|
|
ignorewin=*clk/8;
|
|
bitnum++;
|
|
//else if no bars found
|
|
}else if(dest[i]<high && dest[i]>low) {
|
|
if (ignorewin==0){
|
|
bitHigh=0;
|
|
}else ignorewin--;
|
|
//if we are past a clock point
|
|
if (i>=lastBit+*clk+tol){ //clock val
|
|
lastBit+=*clk;
|
|
dest[bitnum]=curBit;
|
|
bitnum++;
|
|
}
|
|
//else if bar found but we are not at a clock bit and we did not just have a clock bit
|
|
}else if ((dest[i]>=high || dest[i]<=low) && ((i<lastBit+*clk-tol) || (i>lastBit+*clk+tol)) && (bitHigh==0)){
|
|
//error bar found no clock...
|
|
bitHigh=1;
|
|
dest[bitnum]=77;
|
|
bitnum++;
|
|
errCnt++;
|
|
}
|
|
if (bitnum >=1000) break;
|
|
}
|
|
*size=bitnum;
|
|
} else{
|
|
*size=bitnum;
|
|
*clk=bestStart;
|
|
return -1;
|
|
}
|
|
|
|
if (bitnum>16){
|
|
*size=bitnum;
|
|
} else return -1;
|
|
return errCnt;
|
|
}
|
|
|