+uint32_t OutputEM4x50_Block(uint8_t *BitStream, size_t size, bool verbose, bool pTest)
+{
+ if (size<45) return 0;
+ uint32_t code = bytebits_to_byte(BitStream,8);
+ code = code<<8 | bytebits_to_byte(BitStream+9,8);
+ code = code<<8 | bytebits_to_byte(BitStream+18,8);
+ code = code<<8 | bytebits_to_byte(BitStream+27,8);
+ if (verbose || g_debugMode){
+ for (uint8_t i = 0; i<5; i++){
+ if (i == 4) PrintAndLog(""); //parity byte spacer
+ PrintAndLog("%d%d%d%d%d%d%d%d %d -> 0x%02x",
+ BitStream[i*9],
+ BitStream[i*9+1],
+ BitStream[i*9+2],
+ BitStream[i*9+3],
+ BitStream[i*9+4],
+ BitStream[i*9+5],
+ BitStream[i*9+6],
+ BitStream[i*9+7],
+ BitStream[i*9+8],
+ bytebits_to_byte(BitStream+i*9,8)
+ );
+ }
+ if (pTest)
+ PrintAndLog("Parity Passed");
+ else
+ PrintAndLog("Parity Failed");
+ }
+ return code;
+}
+/* Read the transmitted data of an EM4x50 tag from the graphbuffer
+ * Format:
+ *
+ * XXXXXXXX [row parity bit (even)] <- 8 bits plus parity
+ * XXXXXXXX [row parity bit (even)] <- 8 bits plus parity
+ * XXXXXXXX [row parity bit (even)] <- 8 bits plus parity
+ * XXXXXXXX [row parity bit (even)] <- 8 bits plus parity
+ * CCCCCCCC <- column parity bits
+ * 0 <- stop bit
+ * LW <- Listen Window
+ *
+ * This pattern repeats for every block of data being transmitted.
+ * Transmission starts with two Listen Windows (LW - a modulated
+ * pattern of 320 cycles each (32/32/128/64/64)).
+ *
+ * Note that this data may or may not be the UID. It is whatever data
+ * is stored in the blocks defined in the control word First and Last
+ * Word Read values. UID is stored in block 32.
+ */
+ //completed by Marshmellow
+int EM4x50Read(const char *Cmd, bool verbose)
+{
+ uint8_t fndClk[] = {8,16,32,40,50,64,128};
+ int clk = 0;
+ int invert = 0;
+ int tol = 0;
+ int i, j, startblock, skip, block, start, end, low, high, minClk;
+ bool complete = false;
+ int tmpbuff[MAX_GRAPH_TRACE_LEN / 64];
+ uint32_t Code[6];
+ char tmp[6];
+ char tmp2[20];
+ int phaseoff;
+ high = low = 0;
+ memset(tmpbuff, 0, MAX_GRAPH_TRACE_LEN / 64);
+
+ // get user entry if any
+ sscanf(Cmd, "%i %i", &clk, &invert);
+
+ // save GraphBuffer - to restore it later
+ save_restoreGB(1);
+
+ // first get high and low values
+ for (i = 0; i < GraphTraceLen; i++) {
+ if (GraphBuffer[i] > high)
+ high = GraphBuffer[i];
+ else if (GraphBuffer[i] < low)
+ low = GraphBuffer[i];
+ }
+
+ i = 0;
+ j = 0;
+ minClk = 255;
+ // get to first full low to prime loop and skip incomplete first pulse
+ while ((GraphBuffer[i] < high) && (i < GraphTraceLen))
+ ++i;
+ while ((GraphBuffer[i] > low) && (i < GraphTraceLen))
+ ++i;
+ skip = i;
+
+ // populate tmpbuff buffer with pulse lengths
+ while (i < GraphTraceLen) {
+ // measure from low to low
+ while ((GraphBuffer[i] > low) && (i < GraphTraceLen))
+ ++i;
+ start= i;
+ while ((GraphBuffer[i] < high) && (i < GraphTraceLen))
+ ++i;
+ while ((GraphBuffer[i] > low) && (i < GraphTraceLen))
+ ++i;
+ if (j>=(MAX_GRAPH_TRACE_LEN/64)) {
+ break;
+ }
+ tmpbuff[j++]= i - start;
+ if (i-start < minClk && i < GraphTraceLen) {
+ minClk = i - start;
+ }
+ }
+ // set clock
+ 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;
+ }
+ }
+ if (!clk) return 0;
+ } else tol = clk/8;
+
+ // look for data start - should be 2 pairs of LW (pulses of clk*3,clk*2)
+ start = -1;
+ for (i= 0; i < j - 4 ; ++i) {
+ skip += tmpbuff[i];
+ if (tmpbuff[i] >= clk*3-tol && tmpbuff[i] <= clk*3+tol) //3 clocks
+ if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol) //2 clocks
+ if (tmpbuff[i+2] >= clk*3-tol && tmpbuff[i+2] <= clk*3+tol) //3 clocks
+ if (tmpbuff[i+3] >= clk-tol) //1.5 to 2 clocks - depends on bit following
+ {
+ start= i + 4;
+ break;
+ }
+ }
+ startblock = i + 4;
+
+ // skip over the remainder of LW
+ skip += tmpbuff[i+1] + tmpbuff[i+2] + clk;
+ if (tmpbuff[i+3]>clk)
+ phaseoff = tmpbuff[i+3]-clk;
+ else
+ phaseoff = 0;
+ // now do it again to find the end
+ end = skip;
+ for (i += 3; i < j - 4 ; ++i) {
+ end += tmpbuff[i];
+ if (tmpbuff[i] >= clk*3-tol && tmpbuff[i] <= clk*3+tol) //3 clocks
+ if (tmpbuff[i+1] >= clk*2-tol && tmpbuff[i+1] <= clk*2+tol) //2 clocks
+ if (tmpbuff[i+2] >= clk*3-tol && tmpbuff[i+2] <= clk*3+tol) //3 clocks
+ if (tmpbuff[i+3] >= clk-tol) //1.5 to 2 clocks - depends on bit following
+ {
+ complete= true;
+ break;
+ }
+ }
+ end = i;
+ // report back
+ if (verbose || g_debugMode) {
+ if (start >= 0) {
+ PrintAndLog("\nNote: one block = 50 bits (32 data, 12 parity, 6 marker)");
+ } else {
+ PrintAndLog("No data found!, clock tried:%d",clk);
+ PrintAndLog("Try again with more samples.");
+ PrintAndLog(" or after a 'data askedge' command to clean up the read");
+ return 0;
+ }
+ } else if (start < 0) return 0;
+ start = skip;
+ snprintf(tmp2, sizeof(tmp2),"%d %d 1000 %d", clk, invert, clk*47);
+ // get rid of leading crap
+ snprintf(tmp, sizeof(tmp), "%i", skip);
+ CmdLtrim(tmp);
+ bool pTest;
+ bool AllPTest = true;
+ // now work through remaining buffer printing out data blocks
+ block = 0;
+ i = startblock;
+ while (block < 6) {
+ if (verbose || g_debugMode) PrintAndLog("\nBlock %i:", block);
+ skip = phaseoff;
+
+ // look for LW before start of next block
+ for ( ; i < j - 4 ; ++i) {
+ skip += tmpbuff[i];
+ if (tmpbuff[i] >= clk*3-tol && tmpbuff[i] <= clk*3+tol)
+ if (tmpbuff[i+1] >= clk-tol)
+ break;
+ }
+ if (i >= j-4) break; //next LW not found
+ skip += clk;
+ if (tmpbuff[i+1]>clk)
+ phaseoff = tmpbuff[i+1]-clk;
+ else
+ phaseoff = 0;
+ i += 2;
+ if (ASKDemod(tmp2, false, false, 1) < 1) {
+ save_restoreGB(0);
+ return 0;
+ }
+ //set DemodBufferLen to just one block
+ DemodBufferLen = skip/clk;
+ //test parities
+ pTest = EM_ByteParityTest(DemodBuffer,DemodBufferLen,5,9,0);
+ pTest &= EM_EndParityTest(DemodBuffer,DemodBufferLen,5,9,0);
+ AllPTest &= pTest;
+ //get output
+ Code[block] = OutputEM4x50_Block(DemodBuffer,DemodBufferLen,verbose, pTest);
+ if (g_debugMode) PrintAndLog("\nskipping %d samples, bits:%d", skip, skip/clk);
+ //skip to start of next block
+ snprintf(tmp,sizeof(tmp),"%i",skip);
+ CmdLtrim(tmp);
+ block++;
+ if (i >= end) break; //in case chip doesn't output 6 blocks
+ }
+ //print full code:
+ if (verbose || g_debugMode || AllPTest){
+ if (!complete) {
+ PrintAndLog("*** Warning!");
+ PrintAndLog("Partial data - no end found!");
+ PrintAndLog("Try again with more samples.");
+ }
+ PrintAndLog("Found data at sample: %i - using clock: %i", start, clk);
+ end = block;
+ for (block=0; block < end; block++){
+ PrintAndLog("Block %d: %08x",block,Code[block]);
+ }
+ if (AllPTest) {
+ PrintAndLog("Parities Passed");
+ } else {
+ PrintAndLog("Parities Failed");
+ PrintAndLog("Try cleaning the read samples with 'data askedge'");
+ }
+ }
+
+ //restore GraphBuffer
+ save_restoreGB(0);
+ return (int)AllPTest;
+}
+
+int CmdEM4x50Read(const char *Cmd)
+{
+ return EM4x50Read(Cmd, true);
+}
+
+int usage_lf_em_read(void) {
+ PrintAndLog("Read EM4x05/EM4x69. Tag must be on antenna. ");
+ PrintAndLog("");
+ PrintAndLog("Usage: lf em readword [h] <address> <pwd>");
+ PrintAndLog("Options:");
+ PrintAndLog(" h - this help");
+ PrintAndLog(" address - memory address to read. (0-15)");
+ PrintAndLog(" pwd - password (hex) (optional)");
+ PrintAndLog("samples:");
+ PrintAndLog(" lf em readword 1");
+ PrintAndLog(" lf em readword 1 11223344");
+ return 0;
+}
+
+//search for given preamble in given BitStream and return success=1 or fail=0 and startIndex
+uint8_t EMpreambleSearch(uint8_t *BitStream, uint8_t *preamble, size_t pLen, size_t size, size_t *startIdx)
+{
+ // Sanity check. If preamble length is bigger than bitstream length.
+ if ( size <= pLen ) return 0;
+ // em only sends preamble once, so look for it once in the first x bits
+ uint8_t foundCnt = 0;
+ for (int idx = 0; idx < size - pLen; idx++){
+ if (memcmp(BitStream+idx, preamble, pLen) == 0){
+ //first index found
+ foundCnt++;
+ if (foundCnt == 1) {
+ *startIdx = idx;
+ return 1;
+ }
+ }
+ }
+ return 0;
+}
+
+// FSK, PSK, ASK/MANCHESTER, ASK/BIPHASE, ASK/DIPHASE
+// should cover 90% of known used configs
+// the rest will need to be manually demoded for now...
+int demodEM4x05resp(uint8_t bitsNeeded) {
+ int ans = 0;
+ bool demodFound = false;
+ DemodBufferLen = 0x00;
+ // skip first two 0 bits as they might have been missed in the demod
+ uint8_t preamble[6] = {0,0,1,0,1,0};
+
+ // test for FSK wave (easiest to 99% ID)
+ if (GetFskClock("", FALSE, FALSE)) {
+ //valid fsk clocks found
+ ans = FSKrawDemod("0 0", false);
+ if (!ans) {
+ if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: FSK Demod failed");
+ } else {
+ // set size to 10 to only test first 4 positions for the preamble
+ size_t size = (10 > DemodBufferLen) ? DemodBufferLen : 10;
+ size_t startIdx = 0;
+
+ if (g_debugMode) PrintAndLog("ANS: %d | %u | %u", ans, startIdx, size);
+
+ uint8_t errChk = !EMpreambleSearch(DemodBuffer, preamble, sizeof(preamble), size, &startIdx);
+ if ( errChk == 0) {
+ if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305 preamble not found :: %d", startIdx);
+ } else {
+ //can't test size because the preamble doesn't repeat :(
+ //meaning chances of false positives are high.
+ demodFound = true;
+ }
+ }
+ }
+ // PSK clocks should be easy to detect ( but difficult to demod a non-repeating pattern... )
+ if (!demodFound) {
+ ans = GetPskClock("", FALSE, FALSE);
+ if (ans>0) {
+ PrintAndLog("PSK response possibly found, run `data rawd p1` to attempt to demod");
+ }
+ }
+
+ // more common than biphase
+ if (!demodFound) {
+ DemodBufferLen = 0x00;
+ // try manchester - NOTE: ST only applies to T55x7 tags.
+ ans = ASKDemod_ext("0,0,1", false, false, 1, false);
+ if (!ans) {
+ if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: ASK/Manchester Demod failed");
+ } else {
+ // set size to 10 to only test first 4 positions for the preamble
+ size_t size = (10 > DemodBufferLen) ? DemodBufferLen : 10;
+ size_t startIdx = 0;
+
+ if (g_debugMode) PrintAndLog("ANS: %d | %u | %u", ans, startIdx, size);
+
+ uint8_t errChk = !EMpreambleSearch(DemodBuffer, preamble, sizeof(preamble), size, &startIdx);
+ if ( errChk == 0) {
+ if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305 preamble not found :: %d", startIdx);
+ } else {
+ //can't test size because the preamble doesn't repeat :(
+ //meaning chances of false positives are high.
+ demodFound = true;
+ }
+ }
+ }
+
+ if (!demodFound) {
+ DemodBufferLen = 0x00;
+ //try biphase
+ ans = ASKbiphaseDemod("0 0 1", FALSE);
+ if (!ans) {
+ if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: ASK/biphase Demod failed");
+ } else {
+ // set size to 10 to only test first 4 positions for the preamble
+ size_t size = (10 > DemodBufferLen) ? DemodBufferLen : 10;
+ size_t startIdx = 0;
+
+ if (g_debugMode) PrintAndLog("ANS: %d | %u | %u", ans, startIdx, size);
+
+ uint8_t errChk = !EMpreambleSearch(DemodBuffer, preamble, sizeof(preamble), size, &startIdx);
+ if ( errChk == 0) {
+ if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305 preamble not found :: %d", startIdx);
+ } else {
+ //can't test size because the preamble doesn't repeat :(
+ //meaning chances of false positives are high.
+ demodFound = true;
+ }
+ }
+ }
+
+ if (!demodFound) {
+ DemodBufferLen = 0x00;
+ //try diphase (differential biphase or inverted)
+ ans = ASKbiphaseDemod("0 1 1", FALSE);
+ if (!ans) {
+ if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305: ASK/biphase Demod failed");
+ } else {
+ // set size to 10 to only test first 4 positions for the preamble
+ size_t size = (10 > DemodBufferLen) ? DemodBufferLen : 10;
+ size_t startIdx = 0;
+
+ if (g_debugMode) PrintAndLog("ANS: %d | %u | %u", ans, startIdx, size);
+
+ uint8_t errChk = !EMpreambleSearch(DemodBuffer, preamble, sizeof(preamble), size, &startIdx);
+ if ( errChk == 0) {
+ if (g_debugMode) PrintAndLog("DEBUG: Error - EM4305 preamble not found :: %d", startIdx);
+ } else {
+ //can't test size because the preamble doesn't repeat :(
+ //meaning chances of false positives are high.
+ demodFound = true;
+ }
+ }
+ }
+
+ if (demodFound && bitsNeeded < DemodBufferLen) {
+ if (bitsNeeded > 0) {
+ setDemodBuf(DemodBuffer + ans + sizeof(preamble), bitsNeeded, 0);
+ CmdPrintDemodBuff("x");
+ }
+ return 1;
+ }
+ return -1;
+}
+
+int CmdReadWord(const char *Cmd) {
+ int addr, pwd;
+ bool usePwd = false;
+ uint8_t ctmp = param_getchar(Cmd, 0);
+ if ( strlen(Cmd) == 0 || ctmp == 'H' || ctmp == 'h' ) return usage_lf_em_read();
+
+ addr = param_get8ex(Cmd, 0, -1, 10);
+ pwd = param_get32ex(Cmd, 1, -1, 16);
+
+ if ( (addr > 15) || (addr < 0 ) || ( addr == -1) ) {
+ PrintAndLog("Address must be between 0 and 15");
+ return 1;
+ }
+ if ( pwd == -1 )
+ PrintAndLog("Reading address %d", addr);
+ else {
+ usePwd = true;
+ PrintAndLog("Reading address %d | password %08X", addr, pwd);
+ }
+
+ UsbCommand c = {CMD_EM4X_READ_WORD, {addr, pwd, usePwd}};
+ clearCommandBuffer();
+ SendCommand(&c);
+ UsbCommand resp;
+ if (!WaitForResponseTimeout(CMD_ACK, &resp, 2500)){
+ PrintAndLog("Command timed out");
+ return -1;
+ }
+
+ uint8_t got[6000];
+ GetFromBigBuf(got, sizeof(got), 0);
+ if ( !WaitForResponseTimeout(CMD_ACK, NULL, 2500) ) {
+ PrintAndLog("command execution time out");
+ return -1;
+ }
+ setGraphBuf(got, sizeof(got));
+ int testLen = (GraphTraceLen < 1000) ? GraphTraceLen : 1000;
+ if (graphJustNoise(GraphBuffer, testLen)) {
+ PrintAndLog("no tag not found");
+ return -1;
+ }
+
+ //attempt demod:
+ //need 32 bits from a read word
+ return demodEM4x05resp(32);
+}
+
+int usage_lf_em_write(void) {
+ PrintAndLog("Write EM4x05/EM4x69. Tag must be on antenna. ");
+ PrintAndLog("");
+ PrintAndLog("Usage: lf em writeword [h] <address> <data> <pwd>");
+ PrintAndLog("Options:");
+ PrintAndLog(" h - this help");
+ PrintAndLog(" address - memory address to write to. (0-15)");
+ PrintAndLog(" data - data to write (hex)");
+ PrintAndLog(" pwd - password (hex) (optional)");
+ PrintAndLog("samples:");
+ PrintAndLog(" lf em writeword 1");
+ PrintAndLog(" lf em writeword 1 deadc0de 11223344");
+ return 0;
+}
+
+int CmdWriteWord(const char *Cmd) {
+ uint8_t ctmp = param_getchar(Cmd, 0);
+ if ( strlen(Cmd) == 0 || ctmp == 'H' || ctmp == 'h' ) return usage_lf_em_write();
+
+ bool usePwd = false;
+
+ int addr = 16; // default to invalid address
+ int data = 0xFFFFFFFF; // default to blank data
+ int pwd = 0xFFFFFFFF; // default to blank password
+
+ addr = param_get8ex(Cmd, 0, -1, 10);
+ data = param_get32ex(Cmd, 1, -1, 16);
+ pwd = param_get32ex(Cmd, 2, -1, 16);
+
+
+ if ( (addr > 15) || (addr < 0 ) || ( addr == -1) ) {
+ PrintAndLog("Address must be between 0 and 15");
+ return 1;
+ }
+ if ( pwd == -1 )
+ PrintAndLog("Writing address %d data %08X", addr, data);
+ else {
+ usePwd = true;
+ PrintAndLog("Writing address %d data %08X using password %08X", addr, data, pwd);
+ }
+
+ uint16_t flag = (addr << 8 ) | usePwd;
+
+ UsbCommand c = {CMD_EM4X_WRITE_WORD, {flag, data, pwd}};
+ clearCommandBuffer();
+ SendCommand(&c);
+ UsbCommand resp;
+ if (!WaitForResponseTimeout(CMD_ACK, &resp, 1000)){
+ PrintAndLog("Error occurred, device did not respond during write operation.");
+ return -1;
+ }
+ //get response if there is one
+ uint8_t got[6000]; // 8 bit preamble + 32 bit word response (max clock (128) * 40bits = 5120 samples)
+ GetFromBigBuf(got, sizeof(got), 0);
+ if ( !WaitForResponseTimeout(CMD_ACK, NULL, 8000) ) {
+ PrintAndLog("command execution time out");
+ return 0;
+ }
+ setGraphBuf(got, sizeof(got));
+ //todo: check response for 00001010 then write data for write confirmation!
+
+ //attempt demod:
+ //need 0 bits demoded (after preamble) to verify write cmd
+ int result = demodEM4x05resp(0);
+ if (result == 1) {
+ PrintAndLog("Write Verified");
+ }
+ return result;
+}
+
+/*