X-Git-Url: http://cvs.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/a126332a7b3c85274a9988f8a6994fba930b5f52..7f0cb92e0d91031d30d1db92b6df9849571baeeb:/common/lfdemod.c
diff --git a/common/lfdemod.c b/common/lfdemod.c
index 5766c3b6..862d05ba 100644
--- a/common/lfdemod.c
+++ b/common/lfdemod.c
@@ -9,9 +9,8 @@
//-----------------------------------------------------------------------------
#include <stdlib.h>
-#include <string.h>
#include "lfdemod.h"
-#include "common.h"
+#include <string.h>
//un_comment to allow debug print calls when used not on device
void dummy(char *fmt, ...){}
@@ -69,7 +68,7 @@ uint8_t parityTest(uint32_t bits, uint8_t bitLen, uint8_t pType)
//by marshmellow
// takes a array of binary values, start position, length of bits per parity (includes parity bit),
-// Parity Type (1 for odd; 0 for even; 2 Always 1's), and binary Length (length to run)
+// Parity Type (1 for odd; 0 for even; 2 for Always 1's; 3 for Always 0's), and binary Length (length to run)
size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t pType, size_t bLen)
{
uint32_t parityWd = 0;
@@ -81,10 +80,11 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p
}
j--; // overwrite parity with next data
// if parity fails then return 0
- if (pType == 2) { // then marker bit which should be a 1
- if (!BitStream[j]) return 0;
- } else {
- if (parityTest(parityWd, pLen, pType) == 0) return 0;
+ switch (pType) {
+ case 3: if (BitStream[j]==1) return 0; break; //should be 0 spacer bit
+ case 2: if (BitStream[j]==0) return 0; break; //should be 1 spacer bit
+ default: //test parity
+ if (parityTest(parityWd, pLen, pType) == 0) return 0; break;
}
bitCnt+=(pLen-1);
parityWd = 0;
@@ -96,7 +96,8 @@ size_t removeParity(uint8_t *BitStream, size_t startIdx, uint8_t pLen, uint8_t p
// by marshmellow
// takes a array of binary values, length of bits per parity (includes parity bit),
-// Parity Type (1 for odd; 0 for even; 2 Always 1's), and binary Length (length to run)
+// Parity Type (1 for odd; 0 for even; 2 Always 1's; 3 Always 0's), and binary Length (length to run)
+// Make sure *dest is long enough to store original sourceLen + #_of_parities_to_be_added
size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t pLen, uint8_t pType)
{
uint32_t parityWd = 0;
@@ -106,11 +107,14 @@ size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t p
parityWd = (parityWd << 1) | BitSource[word+bit];
dest[j++] = (BitSource[word+bit]);
}
+
// if parity fails then return 0
- if (pType == 2) { // then marker bit which should be a 1
- dest[j++]=1;
- } else {
- dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1;
+ switch (pType) {
+ case 3: dest[j++]=0; break; // marker bit which should be a 0
+ case 2: dest[j++]=1; break; // marker bit which should be a 1
+ default:
+ dest[j++] = parityTest(parityWd, pLen-1, pType) ^ 1;
+ break;
}
bitCnt += pLen;
parityWd = 0;
@@ -123,8 +127,7 @@ size_t addParity(uint8_t *BitSource, uint8_t *dest, uint8_t sourceLen, uint8_t p
uint32_t bytebits_to_byte(uint8_t *src, size_t numbits)
{
uint32_t num = 0;
- for(int i = 0 ; i < numbits ; i++)
- {
+ for(int i = 0 ; i < numbits ; i++) {
num = (num << 1) | (*src);
src++;
}
@@ -135,8 +138,7 @@ uint32_t bytebits_to_byte(uint8_t *src, size_t numbits)
uint32_t bytebits_to_byteLSBF(uint8_t *src, size_t numbits)
{
uint32_t num = 0;
- for(int i = 0 ; i < numbits ; i++)
- {
+ for(int i = 0 ; i < numbits ; i++) {
num = (num << 1) | *(src + (numbits-(i+1)));
}
return num;
@@ -218,6 +220,7 @@ int cleanAskRawDemod(uint8_t *BinStream, size_t *size, int clk, int invert, int
if (smplCnt > clk-(clk/4)-1) { //full clock
if (smplCnt > clk + (clk/4)+1) { //too many samples
errCnt++;
+ if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
BinStream[bitCnt++]=7;
} else if (waveHigh) {
BinStream[bitCnt++] = invert;
@@ -274,7 +277,7 @@ int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr
if (*clk==0 || start < 0) return -3;
if (*invert != 1) *invert = 0;
if (amp==1) askAmp(BinStream, *size);
- if (g_debugMode==2) prnt("DEBUG: clk %d, beststart %d", *clk, start);
+ if (g_debugMode==2) prnt("DEBUG ASK: clk %d, beststart %d", *clk, start);
uint8_t initLoopMax = 255;
if (initLoopMax > *size) initLoopMax = *size;
@@ -287,20 +290,21 @@ int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr
size_t errCnt = 0;
// if clean clipped waves detected run alternate demod
if (DetectCleanAskWave(BinStream, *size, high, low)) {
- if (g_debugMode==2) prnt("DEBUG: Clean Wave Detected");
+ if (g_debugMode==2) prnt("DEBUG ASK: Clean Wave Detected - using clean wave demod");
errCnt = cleanAskRawDemod(BinStream, size, *clk, *invert, high, low);
if (askType) //askman
return manrawdecode(BinStream, size, 0);
else //askraw
return errCnt;
}
+ if (g_debugMode==2) prnt("DEBUG ASK: Weak Wave Detected - using weak wave demod");
int lastBit; //set first clock check - can go negative
size_t i, bitnum = 0; //output counter
uint8_t midBit = 0;
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
- size_t MaxBits = 1024;
+ size_t MaxBits = 3072; //max bits to collect
lastBit = start - *clk;
for (i = start; i < *size; ++i) {
@@ -311,6 +315,7 @@ int askdemod(uint8_t *BinStream, size_t *size, int *clk, int *invert, int maxErr
BinStream[bitnum++] = *invert ^ 1;
} else if (i-lastBit >= *clk+tol) {
if (bitnum > 0) {
+ if (g_debugMode==2) prnt("DEBUG ASK: Modulation Error at: %u", i);
BinStream[bitnum++]=7;
errCnt++;
}
@@ -483,7 +488,7 @@ size_t fsk_wave_demod(uint8_t * dest, size_t size, uint8_t fchigh, uint8_t fclow
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
+ // or 10 (fc/10) cycles but in practice due to noise etc we may end up with anywhere
// between 7 to 11 cycles so fuzz it by treat anything <9 as 8 and anything else as 10
for(idx = 161; idx < size-20; idx++) {
// threshold current value
@@ -678,6 +683,20 @@ int VikingDemod_AM(uint8_t *dest, size_t *size) {
return (int) startIdx;
}
+// find presco preamble 0x10D in already demoded data
+int PrescoDemod(uint8_t *dest, size_t *size) {
+ //make sure buffer has data
+ if (*size < 64*2) return -2;
+
+ size_t startIdx = 0;
+ uint8_t preamble[] = {1,0,0,0,0,1,1,0,1,0,0,0,0,0,0,0,0,0,0,0};
+ uint8_t errChk = preambleSearch(dest, preamble, sizeof(preamble), size, &startIdx);
+ if (errChk == 0) return -4; //preamble not found
+ //return start position
+ return (int) startIdx;
+}
+
+
// Ask/Biphase Demod then try to locate an ISO 11784/85 ID
// BitStream must contain previously askrawdemod and biphasedemoded data
int FDXBdemodBI(uint8_t *dest, size_t *size)
@@ -1199,7 +1218,7 @@ int indala26decode(uint8_t *bitStream, size_t *size, uint8_t *invert)
return (int) startidx;
}
-// by marshmellow - demodulate NRZ wave
+// by marshmellow - demodulate NRZ wave - requires a read with strong signal
// peaks invert bit (high=1 low=0) each clock cycle = 1 bit determined by last peak
int nrzRawDemod(uint8_t *dest, size_t *size, int *clk, int *invert){
if (justNoise(dest, *size)) return -1;
@@ -1518,3 +1537,166 @@ int pskRawDemod(uint8_t dest[], size_t *size, int *clock, int *invert)
*size = numBits;
return errCnt;
}
+
+//by marshmellow
+//attempt to identify a Sequence Terminator in ASK modulated raw wave
+bool DetectST(uint8_t buffer[], size_t *size, int *foundclock) {
+ size_t bufsize = *size;
+ //need to loop through all samples and identify our clock, look for the ST pattern
+ uint8_t fndClk[] = {8,16,32,40,50,64,128};
+ int clk = 0;
+ int tol = 0;
+ int i, j, skip, start, end, low, high, minClk, waveStart;
+ bool complete = false;
+ int tmpbuff[bufsize / 64];
+ int waveLen[bufsize / 64];
+ size_t testsize = (bufsize < 512) ? bufsize : 512;
+ int phaseoff = 0;
+ high = low = 128;
+ memset(tmpbuff, 0, sizeof(tmpbuff));
+
+ if ( getHiLo(buffer, testsize, &high, &low, 80, 80) == -1 ) {
+ if (g_debugMode==2) prnt("DEBUG STT: just noise detected - quitting");
+ return false; //just noise
+ }
+ i = 0;
+ j = 0;
+ minClk = 255;
+ // get to first full low to prime loop and skip incomplete first pulse
+ while ((buffer[i] < high) && (i < bufsize))
+ ++i;
+ while ((buffer[i] > low) && (i < bufsize))
+ ++i;
+ skip = i;
+
+ // populate tmpbuff buffer with pulse lengths
+ while (i < bufsize) {
+ // measure from low to low
+ while ((buffer[i] > low) && (i < bufsize))
+ ++i;
+ start= i;
+ while ((buffer[i] < high) && (i < bufsize))
+ ++i;
+ //first high point for this wave
+ waveStart = i;
+ while ((buffer[i] > low) && (i < bufsize))
+ ++i;
+ if (j >= (bufsize/64)) {
+ break;
+ }
+ waveLen[j] = i - waveStart; //first high to first low
+ tmpbuff[j++] = i - start;
+ if (i-start < minClk && i < bufsize) {
+ minClk = i - start;
+ }
+ }
+ // set clock - might be able to get this externally and remove this work...
+ if (!clk) {
+ for (uint8_t clkCnt = 0; clkCnt<7; clkCnt++) {
+ tol = fndClk[clkCnt]/8;
+ if (minClk >= fndClk[clkCnt]-tol && minClk <= fndClk[clkCnt]+1) {
+ clk=fndClk[clkCnt];
+ break;
+ }
+ }
+ // clock not found - ERROR
+ if (!clk) {
+ if (g_debugMode==2) prnt("DEBUG STT: clock not found - quitting");
+ return false;
+ }
+ } else tol = clk/8;
+
+ *foundclock = clk;
+
+ // look for Sequence Terminator - should be pulses of clk*(1 or 1.5), clk*2, clk*(1.5 or 2)
+ start = -1;
+ for (i = 0; i < j - 4; ++i) {
+ skip += tmpbuff[i];
+ if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol && waveLen[i] < clk+tol) { //1 to 2 clocks depending on 2 bits prior
+ if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) { //2 clocks and wave size is 1 1/2
+ if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave
+ if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit
+ start = i + 3;
+ break;
+ }
+ }
+ }
+ }
+ }
+ // first ST not found - ERROR
+ if (start < 0) {
+ if (g_debugMode==2) prnt("DEBUG STT: first STT not found - quitting");
+ return false;
+ }
+ if (waveLen[i+2] > clk*1+tol)
+ phaseoff = 0;
+ else
+ phaseoff = clk/2;
+
+ // skip over the remainder of ST
+ skip += clk*7/2; //3.5 clocks from tmpbuff[i] = end of st - also aligns for ending point
+
+ // now do it again to find the end
+ end = skip;
+ for (i += 3; i < j - 4; ++i) {
+ end += tmpbuff[i];
+ if (tmpbuff[i] >= clk*1-tol && tmpbuff[i] <= (clk*2)+tol) { //1 to 2 clocks depending on 2 bits prior
+ if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol && waveLen[i+1] > clk*3/2-tol) { //2 clocks and wave size is 1 1/2
+ if (tmpbuff[i+2] >= (clk*3)/2-tol && tmpbuff[i+2] <= clk*2+tol && waveLen[i+2] > clk-tol) { //1 1/2 to 2 clocks and at least one full clock wave
+ if (tmpbuff[i+3] >= clk*1-tol && tmpbuff[i+3] <= clk*2+tol) { //1 to 2 clocks for end of ST + first bit
+ complete = true;
+ break;
+ }
+ }
+ }
+ }
+ }
+ end -= phaseoff;
+ //didn't find second ST - ERROR
+ if (!complete) {
+ if (g_debugMode==2) prnt("DEBUG STT: second STT not found - quitting");
+ return false;
+ }
+ if (g_debugMode==2) prnt("DEBUG STT: start of data: %d end of data: %d, datalen: %d, clk: %d, bits: %d, phaseoff: %d", skip, end, end-skip, clk, (end-skip)/clk, phaseoff);
+ //now begin to trim out ST so we can use normal demod cmds
+ start = skip;
+ size_t datalen = end - start;
+ // check validity of datalen (should be even clock increments) - use a tolerance of up to 1/8th a clock
+ if (datalen % clk > clk/8) {
+ if (g_debugMode==2) prnt("DEBUG STT: datalen not divisible by clk: %u %% %d = %d - quitting", datalen, clk, datalen % clk);
+ return false;
+ } else {
+ // padd the amount off - could be problematic... but shouldn't happen often
+ datalen += datalen % clk;
+ }
+ // if datalen is less than one t55xx block - ERROR
+ if (datalen/clk < 8*4) {
+ if (g_debugMode==2) prnt("DEBUG STT: datalen is less than 1 full t55xx block - quitting");
+ return false;
+ }
+ size_t dataloc = start;
+ size_t newloc = 0;
+ i=0;
+ // warning - overwriting buffer given with raw wave data with ST removed...
+ while ( dataloc < bufsize-(clk/2) ) {
+ //compensate for long high at end of ST not being high... (we cut out the high part)
+ if (buffer[dataloc]<high && buffer[dataloc]>low && buffer[dataloc+3]<high && buffer[dataloc+3]>low) {
+ for(i=0; i < clk/2-tol; ++i) {
+ buffer[dataloc+i] = high+5;
+ }
+ }
+ for (i=0; i<datalen; ++i) {
+ if (i+newloc < bufsize) {
+ if (i+newloc < dataloc)
+ buffer[i+newloc] = buffer[dataloc];
+
+ dataloc++;
+ }
+ }
+ newloc += i;
+ //skip next ST
+ dataloc += clk*4;
+ }
+ *size = newloc;
+ return true;
+}