- int lowLen = sizeof(LowTone)/sizeof(int);
- int highLen = sizeof(HighTone)/sizeof(int);
- int convLen = (highLen>lowLen)?highLen:lowLen;
- uint16_t crc;
- int i, j, TagType;
- int lowSum = 0, highSum = 0;;
- int lowTot = 0, highTot = 0;
-
- for (i = 0; i < GraphTraceLen - convLen; i++) {
- lowSum = 0;
- highSum = 0;;
-
- for (j = 0; j < lowLen; j++) {
- lowSum += LowTone[j]*GraphBuffer[i+j];
- }
- for (j = 0; j < highLen; j++) {
- highSum += HighTone[j]*GraphBuffer[i+j];
- }
- lowSum = abs((100*lowSum) / lowLen);
- highSum = abs((100*highSum) / highLen);
- lowSum = (lowSum<0)?-lowSum:lowSum;
- highSum = (highSum<0)?-highSum:highSum;
-
- GraphBuffer[i] = (highSum << 16) | lowSum;
- }
-
- for (i = 0; i < GraphTraceLen - convLen - 16; i++) {
- lowTot = 0;
- highTot = 0;
- // 16 and 15 are f_s divided by f_l and f_h, rounded
- for (j = 0; j < 16; j++) {
- lowTot += (GraphBuffer[i+j] & 0xffff);
- }
- for (j = 0; j < 15; j++) {
- highTot += (GraphBuffer[i+j] >> 16);
- }
- GraphBuffer[i] = lowTot - highTot;
- }
-
- GraphTraceLen -= (convLen + 16);
-
- RepaintGraphWindow();
-
- // TI tag data format is 16 prebits, 8 start bits, 64 data bits,
- // 16 crc CCITT bits, 8 stop bits, 15 end bits
-
- // the 16 prebits are always low
- // the 8 start and stop bits of a tag must match
- // the start/stop prebits of a ro tag are 01111110
- // the start/stop prebits of a rw tag are 11111110
- // the 15 end bits of a ro tag are all low
- // the 15 end bits of a rw tag match bits 15-1 of the data bits
-
- // Okay, so now we have unsliced soft decisions;
- // find bit-sync, and then get some bits.
- // look for 17 low bits followed by 6 highs (common pattern for ro and rw tags)
- int max = 0, maxPos = 0;
- for (i = 0; i < 6000; i++) {
- int j;
- int dec = 0;
- // searching 17 consecutive lows
- for (j = 0; j < 17*lowLen; j++) {
- dec -= GraphBuffer[i+j];
- }
- // searching 7 consecutive highs
- for (; j < 17*lowLen + 6*highLen; j++) {
- dec += GraphBuffer[i+j];
- }
- if (dec > max) {
- max = dec;
- maxPos = i;
- }
- }
-
- // place a marker in the buffer to visually aid location
- // of the start of sync
- GraphBuffer[maxPos] = 800;
- GraphBuffer[maxPos+1] = -800;
-
- // advance pointer to start of actual data stream (after 16 pre and 8 start bits)
- maxPos += 17*lowLen;
- maxPos += 6*highLen;
-
- // place a marker in the buffer to visually aid location
- // of the end of sync
- GraphBuffer[maxPos] = 800;
- GraphBuffer[maxPos+1] = -800;
-
- PrintAndLog("actual data bits start at sample %d", maxPos);
-
- PrintAndLog("length %d/%d", highLen, lowLen);
-
- uint8_t bits[1+64+16+8+16];
- bits[sizeof(bits)-1] = '\0';
-
- uint32_t shift3 = 0x7e000000, shift2 = 0, shift1 = 0, shift0 = 0;
-
- for (i = 0; i < arraylen(bits)-1; i++) {
- int high = 0;
- int low = 0;
- int j;
- for (j = 0; j < lowLen; j++) {
- low -= GraphBuffer[maxPos+j];
- }
- for (j = 0; j < highLen; j++) {
- high += GraphBuffer[maxPos+j];
- }
-
- if (high > low) {
- bits[i] = '1';
- maxPos += highLen;
- // bitstream arrives lsb first so shift right
- shift3 |= (1<<31);
- } else {
- bits[i] = '.';
- maxPos += lowLen;
- }
-
- // 128 bit right shift register
- shift0 = (shift0>>1) | (shift1 << 31);
- shift1 = (shift1>>1) | (shift2 << 31);
- shift2 = (shift2>>1) | (shift3 << 31);
- shift3 >>= 1;
-
- // place a marker in the buffer between bits to visually aid location
- GraphBuffer[maxPos] = 800;
- GraphBuffer[maxPos+1] = -800;
- }
- PrintAndLog("Info: raw tag bits = %s", bits);
-
- TagType = (shift3>>8)&0xff;
- if ( TagType != ((shift0>>16)&0xff) ) {
- PrintAndLog("Error: start and stop bits do not match!");
- return 0;
- }
- else if (TagType == 0x7e) {
- PrintAndLog("Info: Readonly TI tag detected.");
- return 0;
- }
- else if (TagType == 0xfe) {
- PrintAndLog("Info: Rewriteable TI tag detected.");
-
- // put 64 bit data into shift1 and shift0
- shift0 = (shift0>>24) | (shift1 << 8);
- shift1 = (shift1>>24) | (shift2 << 8);
-
- // align 16 bit crc into lower half of shift2
- shift2 = ((shift2>>24) | (shift3 << 8)) & 0x0ffff;
-
- // align 16 bit "end bits" or "ident" into lower half of shift3
- shift3 >>= 16;
-
- // only 15 bits compare, last bit of ident is not valid
- if ( (shift3^shift0)&0x7fff ) {
- PrintAndLog("Error: Ident mismatch!");
- }
- // WARNING the order of the bytes in which we calc crc below needs checking
- // i'm 99% sure the crc algorithm is correct, but it may need to eat the
- // bytes in reverse or something
- // calculate CRC
- crc=0;
- crc = update_crc16(crc, (shift0)&0xff);
- crc = update_crc16(crc, (shift0>>8)&0xff);
- crc = update_crc16(crc, (shift0>>16)&0xff);
- crc = update_crc16(crc, (shift0>>24)&0xff);
- crc = update_crc16(crc, (shift1)&0xff);
- crc = update_crc16(crc, (shift1>>8)&0xff);
- crc = update_crc16(crc, (shift1>>16)&0xff);
- crc = update_crc16(crc, (shift1>>24)&0xff);
- PrintAndLog("Info: Tag data = %08X%08X", shift1, shift0);
- if (crc != (shift2&0xffff)) {
- PrintAndLog("Error: CRC mismatch, calculated %04X, got ^04X", crc, shift2&0xffff);
- } else {
- PrintAndLog("Info: CRC %04X is good", crc);
- }
- }
- else {
- PrintAndLog("Unknown tag type.");
- return 0;
- }
- return 0;
+ int lowLen = sizeof(LowTone)/sizeof(int);
+ int highLen = sizeof(HighTone)/sizeof(int);
+ int convLen = (highLen>lowLen)?highLen:lowLen;
+ uint16_t crc;
+ int i, j, TagType;
+ int lowSum = 0, highSum = 0;;
+ int lowTot = 0, highTot = 0;
+
+ for (i = 0; i < GraphTraceLen - convLen; i++) {
+ lowSum = 0;
+ highSum = 0;;
+
+ for (j = 0; j < lowLen; j++) {
+ lowSum += LowTone[j]*GraphBuffer[i+j];
+ }
+ for (j = 0; j < highLen; j++) {
+ highSum += HighTone[j]*GraphBuffer[i+j];
+ }
+ lowSum = abs((100*lowSum) / lowLen);
+ highSum = abs((100*highSum) / highLen);
+ lowSum = (lowSum<0)?-lowSum:lowSum;
+ highSum = (highSum<0)?-highSum:highSum;
+
+ GraphBuffer[i] = (highSum << 16) | lowSum;
+ }
+
+ for (i = 0; i < GraphTraceLen - convLen - 16; i++) {
+ lowTot = 0;
+ highTot = 0;
+ // 16 and 15 are f_s divided by f_l and f_h, rounded
+ for (j = 0; j < 16; j++) {
+ lowTot += (GraphBuffer[i+j] & 0xffff);
+ }
+ for (j = 0; j < 15; j++) {
+ highTot += (GraphBuffer[i+j] >> 16);
+ }
+ GraphBuffer[i] = lowTot - highTot;
+ }
+
+ GraphTraceLen -= (convLen + 16);
+
+ RepaintGraphWindow();
+
+ // TI tag data format is 16 prebits, 8 start bits, 64 data bits,
+ // 16 crc CCITT bits, 8 stop bits, 15 end bits
+
+ // the 16 prebits are always low
+ // the 8 start and stop bits of a tag must match
+ // the start/stop prebits of a ro tag are 01111110
+ // the start/stop prebits of a rw tag are 11111110
+ // the 15 end bits of a ro tag are all low
+ // the 15 end bits of a rw tag match bits 15-1 of the data bits
+
+ // Okay, so now we have unsliced soft decisions;
+ // find bit-sync, and then get some bits.
+ // look for 17 low bits followed by 6 highs (common pattern for ro and rw tags)
+ int max = 0, maxPos = 0;
+ for (i = 0; i < 6000; i++) {
+ int j;
+ int dec = 0;
+ // searching 17 consecutive lows
+ for (j = 0; j < 17*lowLen; j++) {
+ dec -= GraphBuffer[i+j];
+ }
+ // searching 7 consecutive highs
+ for (; j < 17*lowLen + 6*highLen; j++) {
+ dec += GraphBuffer[i+j];
+ }
+ if (dec > max) {
+ max = dec;
+ maxPos = i;
+ }
+ }
+
+ // place a marker in the buffer to visually aid location
+ // of the start of sync
+ GraphBuffer[maxPos] = 800;
+ GraphBuffer[maxPos+1] = -800;
+
+ // advance pointer to start of actual data stream (after 16 pre and 8 start bits)
+ maxPos += 17*lowLen;
+ maxPos += 6*highLen;
+
+ // place a marker in the buffer to visually aid location
+ // of the end of sync
+ GraphBuffer[maxPos] = 800;
+ GraphBuffer[maxPos+1] = -800;
+
+ PrintAndLog("actual data bits start at sample %d", maxPos);
+
+ PrintAndLog("length %d/%d", highLen, lowLen);
+
+ uint8_t bits[1+64+16+8+16];
+ bits[sizeof(bits)-1] = '\0';
+
+ uint32_t shift3 = 0x7e000000, shift2 = 0, shift1 = 0, shift0 = 0;
+
+ for (i = 0; i < arraylen(bits)-1; i++) {
+ int high = 0;
+ int low = 0;
+ int j;
+ for (j = 0; j < lowLen; j++) {
+ low -= GraphBuffer[maxPos+j];
+ }
+ for (j = 0; j < highLen; j++) {
+ high += GraphBuffer[maxPos+j];
+ }
+
+ if (high > low) {
+ bits[i] = '1';
+ maxPos += highLen;
+ // bitstream arrives lsb first so shift right
+ shift3 |= (1<<31);
+ } else {
+ bits[i] = '.';
+ maxPos += lowLen;
+ }
+
+ // 128 bit right shift register
+ shift0 = (shift0>>1) | (shift1 << 31);
+ shift1 = (shift1>>1) | (shift2 << 31);
+ shift2 = (shift2>>1) | (shift3 << 31);
+ shift3 >>= 1;
+
+ // place a marker in the buffer between bits to visually aid location
+ GraphBuffer[maxPos] = 800;
+ GraphBuffer[maxPos+1] = -800;
+ }
+ PrintAndLog("Info: raw tag bits = %s", bits);
+
+ TagType = (shift3>>8)&0xff;
+ if ( TagType != ((shift0>>16)&0xff) ) {
+ PrintAndLog("Error: start and stop bits do not match!");
+ return 0;
+ }
+ else if (TagType == 0x7e) {
+ PrintAndLog("Info: Readonly TI tag detected.");
+ return 0;
+ }
+ else if (TagType == 0xfe) {
+ PrintAndLog("Info: Rewriteable TI tag detected.");
+
+ // put 64 bit data into shift1 and shift0
+ shift0 = (shift0>>24) | (shift1 << 8);
+ shift1 = (shift1>>24) | (shift2 << 8);
+
+ // align 16 bit crc into lower half of shift2
+ shift2 = ((shift2>>24) | (shift3 << 8)) & 0x0ffff;
+
+ // align 16 bit "end bits" or "ident" into lower half of shift3
+ shift3 >>= 16;
+
+ // only 15 bits compare, last bit of ident is not valid
+ if ( (shift3^shift0)&0x7fff ) {
+ PrintAndLog("Error: Ident mismatch!");
+ }
+ // WARNING the order of the bytes in which we calc crc below needs checking
+ // i'm 99% sure the crc algorithm is correct, but it may need to eat the
+ // bytes in reverse or something
+ // calculate CRC
+ crc=0;
+ crc = update_crc16(crc, (shift0)&0xff);
+ crc = update_crc16(crc, (shift0>>8)&0xff);
+ crc = update_crc16(crc, (shift0>>16)&0xff);
+ crc = update_crc16(crc, (shift0>>24)&0xff);
+ crc = update_crc16(crc, (shift1)&0xff);
+ crc = update_crc16(crc, (shift1>>8)&0xff);
+ crc = update_crc16(crc, (shift1>>16)&0xff);
+ crc = update_crc16(crc, (shift1>>24)&0xff);
+
+ //crc = crc16_ccitt(message, sizeof(message);
+
+ char *crcStr = (crc == (shift2&0xffff) ) ? "Passed" : "Failed";
+
+ PrintAndLog("Tag data = %08X%08X [Crc %04X %s]", shift1, shift0, crc, crcStr );
+
+ if (crc != (shift2&0xffff))
+ PrintAndLog("Error: CRC mismatch, calculated %04X, got ^04X", crc, shift2&0xffff);
+
+ }
+ else {
+ PrintAndLog("Unknown tag type.");
+ }
+ return 0;
projects / proxmark3-svn / blobdiff