X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/30f2a7d38fd35b2427a7eb42e1cd75fb1105f927..31b3689f0b54048de31957e001c60bbd8dfca5a3:/armsrc/iso14443a.c diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c index 0957d051..f2fa1ff2 100644 --- a/armsrc/iso14443a.c +++ b/armsrc/iso14443a.c @@ -1,1815 +1,2842 @@ -//----------------------------------------------------------------------------- -// Routines to support ISO 14443 type A. -// -// Gerhard de Koning Gans - May 2008 -//----------------------------------------------------------------------------- -#include -#include "apps.h" -#include "../common/iso14443_crc.c" - -typedef enum { - SEC_D = 1, - SEC_E = 2, - SEC_F = 3, - SEC_X = 4, - SEC_Y = 5, - SEC_Z = 6 -} SecType; - -//----------------------------------------------------------------------------- -// The software UART that receives commands from the reader, and its state -// variables. -//----------------------------------------------------------------------------- -static struct { - enum { - STATE_UNSYNCD, - STATE_START_OF_COMMUNICATION, - STATE_MILLER_X, - STATE_MILLER_Y, - STATE_MILLER_Z, - STATE_ERROR_WAIT - } state; - WORD shiftReg; - int bitCnt; - int byteCnt; - int byteCntMax; - int posCnt; - int syncBit; - int parityBits; - int samples; - int highCnt; - int bitBuffer; - enum { - DROP_NONE, - DROP_FIRST_HALF, - DROP_SECOND_HALF - } drop; - BYTE *output; -} Uart; - -static BOOL MillerDecoding(int bit) -{ - int error = 0; - int bitright; - - if(!Uart.bitBuffer) { - Uart.bitBuffer = bit ^ 0xFF0; - return FALSE; - } - else { - Uart.bitBuffer <<= 4; - Uart.bitBuffer ^= bit; - } - - BOOL EOC = FALSE; - - if(Uart.state != STATE_UNSYNCD) { - Uart.posCnt++; - - if((Uart.bitBuffer & Uart.syncBit) ^ Uart.syncBit) { - bit = 0x00; - } - else { - bit = 0x01; - } - if(((Uart.bitBuffer << 1) & Uart.syncBit) ^ Uart.syncBit) { - bitright = 0x00; - } - else { - bitright = 0x01; - } - if(bit != bitright) { bit = bitright; } - - if(Uart.posCnt == 1) { - // measurement first half bitperiod - if(!bit) { - Uart.drop = DROP_FIRST_HALF; - } - } - else { - // measurement second half bitperiod - if(!bit & (Uart.drop == DROP_NONE)) { - Uart.drop = DROP_SECOND_HALF; - } - else if(!bit) { - // measured a drop in first and second half - // which should not be possible - Uart.state = STATE_ERROR_WAIT; - error = 0x01; - } - - Uart.posCnt = 0; - - switch(Uart.state) { - case STATE_START_OF_COMMUNICATION: - Uart.shiftReg = 0; - if(Uart.drop == DROP_SECOND_HALF) { - // error, should not happen in SOC - Uart.state = STATE_ERROR_WAIT; - error = 0x02; - } - else { - // correct SOC - Uart.state = STATE_MILLER_Z; - } - break; - - case STATE_MILLER_Z: - Uart.bitCnt++; - Uart.shiftReg >>= 1; - if(Uart.drop == DROP_NONE) { - // logic '0' followed by sequence Y - // end of communication - Uart.state = STATE_UNSYNCD; - EOC = TRUE; - } - // if(Uart.drop == DROP_FIRST_HALF) { - // Uart.state = STATE_MILLER_Z; stay the same - // we see a logic '0' } - if(Uart.drop == DROP_SECOND_HALF) { - // we see a logic '1' - Uart.shiftReg |= 0x100; - Uart.state = STATE_MILLER_X; - } - break; - - case STATE_MILLER_X: - Uart.shiftReg >>= 1; - if(Uart.drop == DROP_NONE) { - // sequence Y, we see a '0' - Uart.state = STATE_MILLER_Y; - Uart.bitCnt++; - } - if(Uart.drop == DROP_FIRST_HALF) { - // Would be STATE_MILLER_Z - // but Z does not follow X, so error - Uart.state = STATE_ERROR_WAIT; - error = 0x03; - } - if(Uart.drop == DROP_SECOND_HALF) { - // We see a '1' and stay in state X - Uart.shiftReg |= 0x100; - Uart.bitCnt++; - } - break; - - case STATE_MILLER_Y: - Uart.bitCnt++; - Uart.shiftReg >>= 1; - if(Uart.drop == DROP_NONE) { - // logic '0' followed by sequence Y - // end of communication - Uart.state = STATE_UNSYNCD; - EOC = TRUE; - } - if(Uart.drop == DROP_FIRST_HALF) { - // we see a '0' - Uart.state = STATE_MILLER_Z; - } - if(Uart.drop == DROP_SECOND_HALF) { - // We see a '1' and go to state X - Uart.shiftReg |= 0x100; - Uart.state = STATE_MILLER_X; - } - break; - - case STATE_ERROR_WAIT: - // That went wrong. Now wait for at least two bit periods - // and try to sync again - if(Uart.drop == DROP_NONE) { - Uart.highCnt = 6; - Uart.state = STATE_UNSYNCD; - } - break; - - default: - Uart.state = STATE_UNSYNCD; - Uart.highCnt = 0; - break; - } - - Uart.drop = DROP_NONE; - - // should have received at least one whole byte... - if((Uart.bitCnt == 2) && EOC && (Uart.byteCnt > 0)) { - return TRUE; - } - - if(Uart.bitCnt == 9) { - Uart.output[Uart.byteCnt] = (Uart.shiftReg & 0xff); - Uart.byteCnt++; - - Uart.parityBits <<= 1; - Uart.parityBits ^= ((Uart.shiftReg >> 8) & 0x01); - - if(EOC) { - // when End of Communication received and - // all data bits processed.. - return TRUE; - } - Uart.bitCnt = 0; - } - - /*if(error) { - Uart.output[Uart.byteCnt] = 0xAA; - Uart.byteCnt++; - Uart.output[Uart.byteCnt] = error & 0xFF; - Uart.byteCnt++; - Uart.output[Uart.byteCnt] = 0xAA; - Uart.byteCnt++; - Uart.output[Uart.byteCnt] = (Uart.bitBuffer >> 8) & 0xFF; - Uart.byteCnt++; - Uart.output[Uart.byteCnt] = Uart.bitBuffer & 0xFF; - Uart.byteCnt++; - Uart.output[Uart.byteCnt] = (Uart.syncBit >> 3) & 0xFF; - Uart.byteCnt++; - Uart.output[Uart.byteCnt] = 0xAA; - Uart.byteCnt++; - return TRUE; - }*/ - } - - } - else { - bit = Uart.bitBuffer & 0xf0; - bit >>= 4; - bit ^= 0x0F; - if(bit) { - // should have been high or at least (4 * 128) / fc - // according to ISO this should be at least (9 * 128 + 20) / fc - if(Uart.highCnt == 8) { - // we went low, so this could be start of communication - // it turns out to be safer to choose a less significant - // syncbit... so we check whether the neighbour also represents the drop - Uart.posCnt = 1; // apparently we are busy with our first half bit period - Uart.syncBit = bit & 8; - Uart.samples = 3; - if(!Uart.syncBit) { Uart.syncBit = bit & 4; Uart.samples = 2; } - else if(bit & 4) { Uart.syncBit = bit & 4; Uart.samples = 2; bit <<= 2; } - if(!Uart.syncBit) { Uart.syncBit = bit & 2; Uart.samples = 1; } - else if(bit & 2) { Uart.syncBit = bit & 2; Uart.samples = 1; bit <<= 1; } - if(!Uart.syncBit) { Uart.syncBit = bit & 1; Uart.samples = 0; - if(Uart.syncBit & (Uart.bitBuffer & 8)) { - Uart.syncBit = 8; - - // the first half bit period is expected in next sample - Uart.posCnt = 0; - Uart.samples = 3; - } - } - else if(bit & 1) { Uart.syncBit = bit & 1; Uart.samples = 0; } - - Uart.syncBit <<= 4; - Uart.state = STATE_START_OF_COMMUNICATION; - Uart.drop = DROP_FIRST_HALF; - Uart.bitCnt = 0; - Uart.byteCnt = 0; - Uart.parityBits = 0; - error = 0; - } - else { - Uart.highCnt = 0; - } - } - else { - if(Uart.highCnt < 8) { - Uart.highCnt++; - } - } - } - - return FALSE; -} - -//============================================================================= -// ISO 14443 Type A - Manchester -//============================================================================= - -static struct { - enum { - DEMOD_UNSYNCD, - DEMOD_START_OF_COMMUNICATION, - DEMOD_MANCHESTER_D, - DEMOD_MANCHESTER_E, - DEMOD_MANCHESTER_F, - DEMOD_ERROR_WAIT - } state; - int bitCount; - int posCount; - int syncBit; - int parityBits; - WORD shiftReg; - int buffer; - int buff; - int samples; - int len; - enum { - SUB_NONE, - SUB_FIRST_HALF, - SUB_SECOND_HALF - } sub; - BYTE *output; -} Demod; - -static BOOL ManchesterDecoding(int v) -{ - int bit; - int modulation; - int error = 0; - - if(!Demod.buff) { - Demod.buff = 1; - Demod.buffer = v; - return FALSE; - } - else { - bit = Demod.buffer; - Demod.buffer = v; - } - - if(Demod.state==DEMOD_UNSYNCD) { - Demod.output[Demod.len] = 0xfa; - Demod.syncBit = 0; - //Demod.samples = 0; - Demod.posCount = 1; // This is the first half bit period, so after syncing handle the second part - if(bit & 0x08) { Demod.syncBit = 0x08; } - if(!Demod.syncBit) { - if(bit & 0x04) { Demod.syncBit = 0x04; } - } - else if(bit & 0x04) { Demod.syncBit = 0x04; bit <<= 4; } - if(!Demod.syncBit) { - if(bit & 0x02) { Demod.syncBit = 0x02; } - } - else if(bit & 0x02) { Demod.syncBit = 0x02; bit <<= 4; } - if(!Demod.syncBit) { - if(bit & 0x01) { Demod.syncBit = 0x01; } - - if(Demod.syncBit & (Demod.buffer & 0x08)) { - Demod.syncBit = 0x08; - - // The first half bitperiod is expected in next sample - Demod.posCount = 0; - Demod.output[Demod.len] = 0xfb; - } - } - else if(bit & 0x01) { Demod.syncBit = 0x01; } - - if(Demod.syncBit) { - Demod.len = 0; - Demod.state = DEMOD_START_OF_COMMUNICATION; - Demod.sub = SUB_FIRST_HALF; - Demod.bitCount = 0; - Demod.shiftReg = 0; - Demod.parityBits = 0; - Demod.samples = 0; - if(Demod.posCount) { - switch(Demod.syncBit) { - case 0x08: Demod.samples = 3; break; - case 0x04: Demod.samples = 2; break; - case 0x02: Demod.samples = 1; break; - case 0x01: Demod.samples = 0; break; - } - } - error = 0; - } - } - else { - //modulation = bit & Demod.syncBit; - modulation = ((bit << 1) ^ ((Demod.buffer & 0x08) >> 3)) & Demod.syncBit; - - Demod.samples += 4; - - if(Demod.posCount==0) { - Demod.posCount = 1; - if(modulation) { - Demod.sub = SUB_FIRST_HALF; - } - else { - Demod.sub = SUB_NONE; - } - } - else { - Demod.posCount = 0; - if(modulation && (Demod.sub == SUB_FIRST_HALF)) { - if(Demod.state!=DEMOD_ERROR_WAIT) { - Demod.state = DEMOD_ERROR_WAIT; - Demod.output[Demod.len] = 0xaa; - error = 0x01; - } - } - else if(modulation) { - Demod.sub = SUB_SECOND_HALF; - } - - switch(Demod.state) { - case DEMOD_START_OF_COMMUNICATION: - if(Demod.sub == SUB_FIRST_HALF) { - Demod.state = DEMOD_MANCHESTER_D; - } - else { - Demod.output[Demod.len] = 0xab; - Demod.state = DEMOD_ERROR_WAIT; - error = 0x02; - } - break; - - case DEMOD_MANCHESTER_D: - case DEMOD_MANCHESTER_E: - if(Demod.sub == SUB_FIRST_HALF) { - Demod.bitCount++; - Demod.shiftReg = (Demod.shiftReg >> 1) ^ 0x100; - Demod.state = DEMOD_MANCHESTER_D; - } - else if(Demod.sub == SUB_SECOND_HALF) { - Demod.bitCount++; - Demod.shiftReg >>= 1; - Demod.state = DEMOD_MANCHESTER_E; - } - else { - Demod.state = DEMOD_MANCHESTER_F; - } - break; - - case DEMOD_MANCHESTER_F: - // Tag response does not need to be a complete byte! - if(Demod.len > 0 || Demod.bitCount > 0) { - if(Demod.bitCount > 0) { - Demod.shiftReg >>= (9 - Demod.bitCount); - Demod.output[Demod.len] = Demod.shiftReg & 0xff; - Demod.len++; - // No parity bit, so just shift a 0 - Demod.parityBits <<= 1; - } - - Demod.state = DEMOD_UNSYNCD; - return TRUE; - } - else { - Demod.output[Demod.len] = 0xad; - Demod.state = DEMOD_ERROR_WAIT; - error = 0x03; - } - break; - - case DEMOD_ERROR_WAIT: - Demod.state = DEMOD_UNSYNCD; - break; - - default: - Demod.output[Demod.len] = 0xdd; - Demod.state = DEMOD_UNSYNCD; - break; - } - - if(Demod.bitCount>=9) { - Demod.output[Demod.len] = Demod.shiftReg & 0xff; - Demod.len++; - - Demod.parityBits <<= 1; - Demod.parityBits ^= ((Demod.shiftReg >> 8) & 0x01); - - Demod.bitCount = 0; - Demod.shiftReg = 0; - } - - /*if(error) { - Demod.output[Demod.len] = 0xBB; - Demod.len++; - Demod.output[Demod.len] = error & 0xFF; - Demod.len++; - Demod.output[Demod.len] = 0xBB; - Demod.len++; - Demod.output[Demod.len] = bit & 0xFF; - Demod.len++; - Demod.output[Demod.len] = Demod.buffer & 0xFF; - Demod.len++; - Demod.output[Demod.len] = Demod.syncBit & 0xFF; - Demod.len++; - Demod.output[Demod.len] = 0xBB; - Demod.len++; - return TRUE; - }*/ - - } - - } // end (state != UNSYNCED) - - return FALSE; -} - -//============================================================================= -// Finally, a `sniffer' for ISO 14443 Type A -// Both sides of communication! -//============================================================================= - -//----------------------------------------------------------------------------- -// Record the sequence of commands sent by the reader to the tag, with -// triggering so that we start recording at the point that the tag is moved -// near the reader. -//----------------------------------------------------------------------------- -void SnoopIso14443a(void) -{ - - // BIG CHANGE - UNDERSTAND THIS BEFORE WE COMMIT - - #define RECV_CMD_OFFSET 3032 - #define RECV_RES_OFFSET 3096 - #define DMA_BUFFER_OFFSET 3160 - #define DMA_BUFFER_SIZE 4096 - #define TRACE_LENGTH 3000 - -// #define RECV_CMD_OFFSET 2032 // original (working as of 21/2/09) values -// #define RECV_RES_OFFSET 2096 // original (working as of 21/2/09) values -// #define DMA_BUFFER_OFFSET 2160 // original (working as of 21/2/09) values -// #define DMA_BUFFER_SIZE 4096 // original (working as of 21/2/09) values -// #define TRACE_LENGTH 2000 // original (working as of 21/2/09) values - - // We won't start recording the frames that we acquire until we trigger; - // a good trigger condition to get started is probably when we see a - // response from the tag. - BOOL triggered = TRUE; // FALSE to wait first for card - - // The command (reader -> tag) that we're receiving. - // The length of a received command will in most cases be no more than 18 bytes. - // So 32 should be enough! - BYTE *receivedCmd = (((BYTE *)BigBuf) + RECV_CMD_OFFSET); - // The response (tag -> reader) that we're receiving. - BYTE *receivedResponse = (((BYTE *)BigBuf) + RECV_RES_OFFSET); - - // As we receive stuff, we copy it from receivedCmd or receivedResponse - // into trace, along with its length and other annotations. - BYTE *trace = (BYTE *)BigBuf; - int traceLen = 0; - - // The DMA buffer, used to stream samples from the FPGA - SBYTE *dmaBuf = ((SBYTE *)BigBuf) + DMA_BUFFER_OFFSET; - int lastRxCounter; - SBYTE *upTo; - int smpl; - int maxBehindBy = 0; - - // Count of samples received so far, so that we can include timing - // information in the trace buffer. - int samples = 0; - int rsamples = 0; - - memset(trace, 0x44, RECV_CMD_OFFSET); - - // Set up the demodulator for tag -> reader responses. - Demod.output = receivedResponse; - Demod.len = 0; - Demod.state = DEMOD_UNSYNCD; - - // And the reader -> tag commands - memset(&Uart, 0, sizeof(Uart)); - Uart.output = receivedCmd; - Uart.byteCntMax = 32; // was 100 (greg)//////////////////////////////////////////////////////////////////////// - Uart.state = STATE_UNSYNCD; - - // And put the FPGA in the appropriate mode - FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_SNIFFER); - SetAdcMuxFor(GPIO_MUXSEL_HIPKD); - - // Setup for the DMA. - FpgaSetupSsc(); - upTo = dmaBuf; - lastRxCounter = DMA_BUFFER_SIZE; - FpgaSetupSscDma((BYTE *)dmaBuf, DMA_BUFFER_SIZE); - - LED_A_ON(); - - // And now we loop, receiving samples. - for(;;) { - WDT_HIT(); - int behindBy = (lastRxCounter - PDC_RX_COUNTER(SSC_BASE)) & - (DMA_BUFFER_SIZE-1); - if(behindBy > maxBehindBy) { - maxBehindBy = behindBy; - if(behindBy > 400) { - DbpString("blew circular buffer!"); - goto done; - } - } - if(behindBy < 1) continue; - - smpl = upTo[0]; - upTo++; - lastRxCounter -= 1; - if(upTo - dmaBuf > DMA_BUFFER_SIZE) { - upTo -= DMA_BUFFER_SIZE; - lastRxCounter += DMA_BUFFER_SIZE; - PDC_RX_NEXT_POINTER(SSC_BASE) = (DWORD)upTo; - PDC_RX_NEXT_COUNTER(SSC_BASE) = DMA_BUFFER_SIZE; - } - - samples += 4; -#define HANDLE_BIT_IF_BODY \ - LED_C_ON(); \ - if(triggered) { \ - trace[traceLen++] = ((rsamples >> 0) & 0xff); \ - trace[traceLen++] = ((rsamples >> 8) & 0xff); \ - trace[traceLen++] = ((rsamples >> 16) & 0xff); \ - trace[traceLen++] = ((rsamples >> 24) & 0xff); \ - trace[traceLen++] = ((Uart.parityBits >> 0) & 0xff); \ - trace[traceLen++] = ((Uart.parityBits >> 8) & 0xff); \ - trace[traceLen++] = ((Uart.parityBits >> 16) & 0xff); \ - trace[traceLen++] = ((Uart.parityBits >> 24) & 0xff); \ - trace[traceLen++] = Uart.byteCnt; \ - memcpy(trace+traceLen, receivedCmd, Uart.byteCnt); \ - traceLen += Uart.byteCnt; \ - if(traceLen > TRACE_LENGTH) break; \ - } \ - /* And ready to receive another command. */ \ - Uart.state = STATE_UNSYNCD; \ - /* And also reset the demod code, which might have been */ \ - /* false-triggered by the commands from the reader. */ \ - Demod.state = DEMOD_UNSYNCD; \ - LED_B_OFF(); \ - - if(MillerDecoding((smpl & 0xF0) >> 4)) { - rsamples = samples - Uart.samples; - HANDLE_BIT_IF_BODY - } - if(ManchesterDecoding(smpl & 0x0F)) { - rsamples = samples - Demod.samples; - LED_B_ON(); - - // timestamp, as a count of samples - trace[traceLen++] = ((rsamples >> 0) & 0xff); - trace[traceLen++] = ((rsamples >> 8) & 0xff); - trace[traceLen++] = ((rsamples >> 16) & 0xff); - trace[traceLen++] = 0x80 | ((rsamples >> 24) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 0) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 8) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 16) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 24) & 0xff); - // length - trace[traceLen++] = Demod.len; - memcpy(trace+traceLen, receivedResponse, Demod.len); - traceLen += Demod.len; - if(traceLen > TRACE_LENGTH) break; - - triggered = TRUE; - - // And ready to receive another response. - memset(&Demod, 0, sizeof(Demod)); - Demod.output = receivedResponse; - Demod.state = DEMOD_UNSYNCD; - LED_C_OFF(); - } - - if(BUTTON_PRESS()) { - DbpString("cancelled_a"); - goto done; - } - } - - DbpString("COMMAND FINISHED"); - - DbpIntegers(maxBehindBy, Uart.state, Uart.byteCnt); - DbpIntegers(Uart.byteCntMax, traceLen, (int)Uart.output[0]); - -done: - PDC_CONTROL(SSC_BASE) = PDC_RX_DISABLE; - DbpIntegers(maxBehindBy, Uart.state, Uart.byteCnt); - DbpIntegers(Uart.byteCntMax, traceLen, (int)Uart.output[0]); - LED_A_OFF(); - LED_B_OFF(); - LED_C_OFF(); - LED_D_OFF(); -} - -// Prepare communication bits to send to FPGA -void Sequence(SecType seq) -{ - ToSendMax++; - switch(seq) { - // CARD TO READER - case SEC_D: - // Sequence D: 11110000 - // modulation with subcarrier during first half - ToSend[ToSendMax] = 0xf0; - break; - case SEC_E: - // Sequence E: 00001111 - // modulation with subcarrier during second half - ToSend[ToSendMax] = 0x0f; - break; - case SEC_F: - // Sequence F: 00000000 - // no modulation with subcarrier - ToSend[ToSendMax] = 0x00; - break; - // READER TO CARD - case SEC_X: - // Sequence X: 00001100 - // drop after half a period - ToSend[ToSendMax] = 0x0c; - break; - case SEC_Y: - default: - // Sequence Y: 00000000 - // no drop - ToSend[ToSendMax] = 0x00; - break; - case SEC_Z: - // Sequence Z: 11000000 - // drop at start - ToSend[ToSendMax] = 0xc0; - break; - } -} - -//----------------------------------------------------------------------------- -// Prepare tag messages -//----------------------------------------------------------------------------- -static void CodeIso14443aAsTag(const BYTE *cmd, int len) -{ - int i; - int oddparity; - - ToSendReset(); - - // Correction bit, might be removed when not needed - ToSendStuffBit(0); - ToSendStuffBit(0); - ToSendStuffBit(0); - ToSendStuffBit(0); - ToSendStuffBit(1); // 1 - ToSendStuffBit(0); - ToSendStuffBit(0); - ToSendStuffBit(0); - - // Send startbit - Sequence(SEC_D); - - for(i = 0; i < len; i++) { - int j; - BYTE b = cmd[i]; - - // Data bits - oddparity = 0x01; - for(j = 0; j < 8; j++) { - oddparity ^= (b & 1); - if(b & 1) { - Sequence(SEC_D); - } else { - Sequence(SEC_E); - } - b >>= 1; - } - - // Parity bit - if(oddparity) { - Sequence(SEC_D); - } else { - Sequence(SEC_E); - } - } - - // Send stopbit - Sequence(SEC_F); - - // Flush the buffer in FPGA!! - for(i = 0; i < 5; i++) { - Sequence(SEC_F); - } - - // Convert from last byte pos to length - ToSendMax++; - - // Add a few more for slop - ToSend[ToSendMax++] = 0x00; - ToSend[ToSendMax++] = 0x00; - //ToSendMax += 2; -} - -//----------------------------------------------------------------------------- -// This is to send a NACK kind of answer, its only 3 bits, I know it should be 4 -//----------------------------------------------------------------------------- -static void CodeStrangeAnswer() -{ - int i; - - ToSendReset(); - - // Correction bit, might be removed when not needed - ToSendStuffBit(0); - ToSendStuffBit(0); - ToSendStuffBit(0); - ToSendStuffBit(0); - ToSendStuffBit(1); // 1 - ToSendStuffBit(0); - ToSendStuffBit(0); - ToSendStuffBit(0); - - // Send startbit - Sequence(SEC_D); - - // 0 - Sequence(SEC_E); - - // 0 - Sequence(SEC_E); - - // 1 - Sequence(SEC_D); - - // Send stopbit - Sequence(SEC_F); - - // Flush the buffer in FPGA!! - for(i = 0; i < 5; i++) { - Sequence(SEC_F); - } - - // Convert from last byte pos to length - ToSendMax++; - - // Add a few more for slop - ToSend[ToSendMax++] = 0x00; - ToSend[ToSendMax++] = 0x00; - //ToSendMax += 2; -} - -//----------------------------------------------------------------------------- -// Wait for commands from reader -// Stop when button is pressed -// Or return TRUE when command is captured -//----------------------------------------------------------------------------- -static BOOL GetIso14443aCommandFromReader(BYTE *received, int *len, int maxLen) -{ - // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen - // only, since we are receiving, not transmitting). - FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN); - - // Now run a `software UART' on the stream of incoming samples. - Uart.output = received; - Uart.byteCntMax = maxLen; - Uart.state = STATE_UNSYNCD; - - for(;;) { - WDT_HIT(); - - if(BUTTON_PRESS()) return FALSE; - - if(SSC_STATUS & (SSC_STATUS_TX_READY)) { - SSC_TRANSMIT_HOLDING = 0x00; - } - if(SSC_STATUS & (SSC_STATUS_RX_READY)) { - BYTE b = (BYTE)SSC_RECEIVE_HOLDING; - if(MillerDecoding((b & 0xf0) >> 4)) { - *len = Uart.byteCnt; - return TRUE; - } - if(MillerDecoding(b & 0x0f)) { - *len = Uart.byteCnt; - return TRUE; - } - } - } -} - -//----------------------------------------------------------------------------- -// Main loop of simulated tag: receive commands from reader, decide what -// response to send, and send it. -//----------------------------------------------------------------------------- -void SimulateIso14443aTag(int tagType, int TagUid) -{ - // This function contains the tag emulation - - // Prepare protocol messages - // static const BYTE cmd1[] = { 0x26 }; -// static const BYTE response1[] = { 0x02, 0x00 }; // Says: I am Mifare 4k - original line - greg -// - static const BYTE response1[] = { 0x44, 0x03 }; // Says: I am a DESFire Tag, ph33r me -// static const BYTE response1[] = { 0x44, 0x00 }; // Says: I am a ULTRALITE Tag, 0wn me - - // UID response - // static const BYTE cmd2[] = { 0x93, 0x20 }; - //static const BYTE response2[] = { 0x9a, 0xe5, 0xe4, 0x43, 0xd8 }; // original value - greg - - - -// my desfire - static const BYTE response2[] = { 0x88, 0x04, 0x21, 0x3f, 0x4d }; // known uid - note cascade (0x88), 2nd byte (0x04) = NXP/Phillips - - -// When reader selects us during cascade1 it will send cmd3 -//BYTE response3[] = { 0x04, 0x00, 0x00 }; // SAK Select (cascade1) successful response (ULTRALITE) -BYTE response3[] = { 0x24, 0x00, 0x00 }; // SAK Select (cascade1) successful response (DESFire) -ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]); - -// send cascade2 2nd half of UID -static const BYTE response2a[] = { 0x51, 0x48, 0x1d, 0x80, 0x84 }; // uid - cascade2 - 2nd half (4 bytes) of UID+ BCCheck -// NOTE : THE CRC on the above may be wrong as I have obfuscated the actual UID - - -// When reader selects us during cascade2 it will send cmd3a -//BYTE response3a[] = { 0x00, 0x00, 0x00 }; // SAK Select (cascade2) successful response (ULTRALITE) -BYTE response3a[] = { 0x20, 0x00, 0x00 }; // SAK Select (cascade2) successful response (DESFire) -ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]); - -// When reader tries to authenticate - // static const BYTE cmd5[] = { 0x60, 0x00, 0xf5, 0x7b }; - static const BYTE response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce - - BYTE *resp; - int respLen; - - // Longest possible response will be 16 bytes + 2 CRC = 18 bytes - // This will need - // 144 data bits (18 * 8) - // 18 parity bits - // 2 Start and stop - // 1 Correction bit (Answer in 1172 or 1236 periods, see FPGA) - // 1 just for the case - // ----------- + - // 166 - // - // 166 bytes, since every bit that needs to be send costs us a byte - // - - - // Respond with card type - BYTE *resp1 = (((BYTE *)BigBuf) + 800); - int resp1Len; - - // Anticollision cascade1 - respond with uid - BYTE *resp2 = (((BYTE *)BigBuf) + 970); - int resp2Len; - - // Anticollision cascade2 - respond with 2nd half of uid if asked - // we're only going to be asked if we set the 1st byte of the UID (during cascade1) to 0x88 - BYTE *resp2a = (((BYTE *)BigBuf) + 1140); - int resp2aLen; - - // Acknowledge select - cascade 1 - BYTE *resp3 = (((BYTE *)BigBuf) + 1310); - int resp3Len; - - // Acknowledge select - cascade 2 - BYTE *resp3a = (((BYTE *)BigBuf) + 1480); - int resp3aLen; - - // Response to a read request - not implemented atm - BYTE *resp4 = (((BYTE *)BigBuf) + 1550); - int resp4Len; - - // Authenticate response - nonce - BYTE *resp5 = (((BYTE *)BigBuf) + 1720); - int resp5Len; - - BYTE *receivedCmd = (BYTE *)BigBuf; - int len; - - int i; - int u; - BYTE b; - - // To control where we are in the protocol - int order = 0; - int lastorder; - - // Just to allow some checks - int happened = 0; - int happened2 = 0; - - int cmdsRecvd = 0; - - BOOL fdt_indicator; - - memset(receivedCmd, 0x44, 400); - - // Prepare the responses of the anticollision phase - // there will be not enough time to do this at the moment the reader sends it REQA - - // Answer to request - CodeIso14443aAsTag(response1, sizeof(response1)); - memcpy(resp1, ToSend, ToSendMax); resp1Len = ToSendMax; - - // Send our UID (cascade 1) - CodeIso14443aAsTag(response2, sizeof(response2)); - memcpy(resp2, ToSend, ToSendMax); resp2Len = ToSendMax; - - // Answer to select (cascade1) - CodeIso14443aAsTag(response3, sizeof(response3)); - memcpy(resp3, ToSend, ToSendMax); resp3Len = ToSendMax; - - // Send the cascade 2 2nd part of the uid - CodeIso14443aAsTag(response2a, sizeof(response2a)); - memcpy(resp2a, ToSend, ToSendMax); resp2aLen = ToSendMax; - - // Answer to select (cascade 2) - CodeIso14443aAsTag(response3a, sizeof(response3a)); - memcpy(resp3a, ToSend, ToSendMax); resp3aLen = ToSendMax; - - // Strange answer is an example of rare message size (3 bits) - CodeStrangeAnswer(); - memcpy(resp4, ToSend, ToSendMax); resp4Len = ToSendMax; - - // Authentication answer (random nonce) - CodeIso14443aAsTag(response5, sizeof(response5)); - memcpy(resp5, ToSend, ToSendMax); resp5Len = ToSendMax; - - // We need to listen to the high-frequency, peak-detected path. - SetAdcMuxFor(GPIO_MUXSEL_HIPKD); - FpgaSetupSsc(); - - cmdsRecvd = 0; - - LED_A_ON(); - for(;;) { - - if(!GetIso14443aCommandFromReader(receivedCmd, &len, 100)) { - DbpString("button press"); - break; - } - // doob - added loads of debug strings so we can see what the reader is saying to us during the sim as hi14alist is not populated - // Okay, look at the command now. - lastorder = order; - i = 1; // first byte transmitted - if(receivedCmd[0] == 0x26) { - // Received a REQUEST - resp = resp1; respLen = resp1Len; order = 1; - //DbpString("Hello request from reader:"); - } else if(receivedCmd[0] == 0x52) { - // Received a WAKEUP - resp = resp1; respLen = resp1Len; order = 6; -// //DbpString("Wakeup request from reader:"); - - } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) { // greg - cascade 1 anti-collision - // Received request for UID (cascade 1) - resp = resp2; respLen = resp2Len; order = 2; -// DbpString("UID (cascade 1) request from reader:"); -// DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]); - - - } else if(receivedCmd[1] == 0x20 && receivedCmd[0] ==0x95) { // greg - cascade 2 anti-collision - // Received request for UID (cascade 2) - resp = resp2a; respLen = resp2aLen; order = 20; -// DbpString("UID (cascade 2) request from reader:"); -// DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]); - - - } else if(receivedCmd[1] == 0x70 && receivedCmd[0] ==0x93) { // greg - cascade 1 select - // Received a SELECT - resp = resp3; respLen = resp3Len; order = 3; -// DbpString("Select (cascade 1) request from reader:"); -// DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]); - - - } else if(receivedCmd[1] == 0x70 && receivedCmd[0] ==0x95) { // greg - cascade 2 select - // Received a SELECT - resp = resp3a; respLen = resp3aLen; order = 30; -// DbpString("Select (cascade 2) request from reader:"); -// DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]); - - - } else if(receivedCmd[0] == 0x30) { - // Received a READ - resp = resp4; respLen = resp4Len; order = 4; // Do nothing - DbpString("Read request from reader:"); - DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]); - - - } else if(receivedCmd[0] == 0x50) { - // Received a HALT - resp = resp1; respLen = 0; order = 5; // Do nothing - DbpString("Reader requested we HALT!:"); - - } else if(receivedCmd[0] == 0x60) { - // Received an authentication request - resp = resp5; respLen = resp5Len; order = 7; - DbpString("Authenticate request from reader:"); - DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]); - - } else if(receivedCmd[0] == 0xE0) { - // Received a RATS request - resp = resp1; respLen = 0;order = 70; - DbpString("RATS request from reader:"); - DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]); - } else { - // Never seen this command before - DbpString("Unknown command received from reader:"); - DbpIntegers(receivedCmd[0], receivedCmd[1], receivedCmd[2]); - DbpIntegers(receivedCmd[3], receivedCmd[4], receivedCmd[5]); - DbpIntegers(receivedCmd[6], receivedCmd[7], receivedCmd[8]); - - // Do not respond - resp = resp1; respLen = 0; order = 0; - } - - // Count number of wakeups received after a halt - if(order == 6 && lastorder == 5) { happened++; } - - // Count number of other messages after a halt - if(order != 6 && lastorder == 5) { happened2++; } - - // Look at last parity bit to determine timing of answer - if((Uart.parityBits & 0x01) || receivedCmd[0] == 0x52) { - // 1236, so correction bit needed - i = 0; - } - - memset(receivedCmd, 0x44, 32); - - if(cmdsRecvd > 999) { - DbpString("1000 commands later..."); - break; - } - else { - cmdsRecvd++; - } - - if(respLen <= 0) continue; - - // Modulate Manchester - FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD); - SSC_TRANSMIT_HOLDING = 0x00; - FpgaSetupSsc(); - - // ### Transmit the response ### - u = 0; - b = 0x00; - fdt_indicator = FALSE; - for(;;) { - if(SSC_STATUS & (SSC_STATUS_RX_READY)) { - volatile BYTE b = (BYTE)SSC_RECEIVE_HOLDING; - (void)b; - } - if(SSC_STATUS & (SSC_STATUS_TX_READY)) { - if(i > respLen) { - b = 0x00; - u++; - } else { - b = resp[i]; - i++; - } - SSC_TRANSMIT_HOLDING = b; - - if(u > 4) { - break; - } - } - if(BUTTON_PRESS()) { - break; - } - } - - } - - DbpIntegers(happened, happened2, cmdsRecvd); - LED_A_OFF(); -} - -//----------------------------------------------------------------------------- -// Transmit the command (to the tag) that was placed in ToSend[]. -//----------------------------------------------------------------------------- -static void TransmitFor14443a(const BYTE *cmd, int len, int *samples, int *wait) -{ - int c; - - FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD); - - if(*wait < 10) { *wait = 10; } - - for(c = 0; c < *wait;) { - if(SSC_STATUS & (SSC_STATUS_TX_READY)) { - SSC_TRANSMIT_HOLDING = 0x00; // For exact timing! - c++; - } - if(SSC_STATUS & (SSC_STATUS_RX_READY)) { - volatile DWORD r = SSC_RECEIVE_HOLDING; - (void)r; - } - WDT_HIT(); - } - - c = 0; - for(;;) { - if(SSC_STATUS & (SSC_STATUS_TX_READY)) { - SSC_TRANSMIT_HOLDING = cmd[c]; - c++; - if(c >= len) { - break; - } - } - if(SSC_STATUS & (SSC_STATUS_RX_READY)) { - volatile DWORD r = SSC_RECEIVE_HOLDING; - (void)r; - } - WDT_HIT(); - } - *samples = (c + *wait) << 3; -} - -//----------------------------------------------------------------------------- -// To generate an arbitrary stream from reader -// -//----------------------------------------------------------------------------- -void ArbitraryFromReader(const BYTE *cmd, int parity, int len) -{ - int i; - int j; - int last; - BYTE b; - - ToSendReset(); - - // Start of Communication (Seq. Z) - Sequence(SEC_Z); - last = 0; - - for(i = 0; i < len; i++) { - // Data bits - b = cmd[i]; - for(j = 0; j < 8; j++) { - if(b & 1) { - // Sequence X - Sequence(SEC_X); - last = 1; - } else { - if(last == 0) { - // Sequence Z - Sequence(SEC_Z); - } - else { - // Sequence Y - Sequence(SEC_Y); - last = 0; - } - } - b >>= 1; - - } - - // Predefined parity bit, the flipper flips when needed, because of flips in byte sent - if(((parity >> (len - i - 1)) & 1)) { - // Sequence X - Sequence(SEC_X); - last = 1; - } else { - if(last == 0) { - // Sequence Z - Sequence(SEC_Z); - } - else { - // Sequence Y - Sequence(SEC_Y); - last = 0; - } - } - } - - // End of Communication - if(last == 0) { - // Sequence Z - Sequence(SEC_Z); - } - else { - // Sequence Y - Sequence(SEC_Y); - last = 0; - } - // Sequence Y - Sequence(SEC_Y); - - // Just to be sure! - Sequence(SEC_Y); - Sequence(SEC_Y); - Sequence(SEC_Y); - - // Convert from last character reference to length - ToSendMax++; -} - -//----------------------------------------------------------------------------- -// Code a 7-bit command without parity bit -// This is especially for 0x26 and 0x52 (REQA and WUPA) -//----------------------------------------------------------------------------- -void ShortFrameFromReader(const BYTE *cmd) -{ - int j; - int last; - BYTE b; - - ToSendReset(); - - // Start of Communication (Seq. Z) - Sequence(SEC_Z); - last = 0; - - b = cmd[0]; - for(j = 0; j < 7; j++) { - if(b & 1) { - // Sequence X - Sequence(SEC_X); - last = 1; - } else { - if(last == 0) { - // Sequence Z - Sequence(SEC_Z); - } - else { - // Sequence Y - Sequence(SEC_Y); - last = 0; - } - } - b >>= 1; - } - - // End of Communication - if(last == 0) { - // Sequence Z - Sequence(SEC_Z); - } - else { - // Sequence Y - Sequence(SEC_Y); - last = 0; - } - // Sequence Y - Sequence(SEC_Y); - - // Just to be sure! - Sequence(SEC_Y); - Sequence(SEC_Y); - Sequence(SEC_Y); - - // Convert from last character reference to length - ToSendMax++; -} - -//----------------------------------------------------------------------------- -// Prepare reader command to send to FPGA -// -//----------------------------------------------------------------------------- -void CodeIso14443aAsReader(const BYTE *cmd, int len) -{ - int i, j; - int last; - int oddparity; - BYTE b; - - ToSendReset(); - - // Start of Communication (Seq. Z) - Sequence(SEC_Z); - last = 0; - - for(i = 0; i < len; i++) { - // Data bits - b = cmd[i]; - oddparity = 0x01; - for(j = 0; j < 8; j++) { - oddparity ^= (b & 1); - if(b & 1) { - // Sequence X - Sequence(SEC_X); - last = 1; - } else { - if(last == 0) { - // Sequence Z - Sequence(SEC_Z); - } - else { - // Sequence Y - Sequence(SEC_Y); - last = 0; - } - } - b >>= 1; - } - - // Parity bit - if(oddparity) { - // Sequence X - Sequence(SEC_X); - last = 1; - } else { - if(last == 0) { - // Sequence Z - Sequence(SEC_Z); - } - else { - // Sequence Y - Sequence(SEC_Y); - last = 0; - } - } - } - - // End of Communication - if(last == 0) { - // Sequence Z - Sequence(SEC_Z); - } - else { - // Sequence Y - Sequence(SEC_Y); - last = 0; - } - // Sequence Y - Sequence(SEC_Y); - - // Just to be sure! - Sequence(SEC_Y); - Sequence(SEC_Y); - Sequence(SEC_Y); - - // Convert from last character reference to length - ToSendMax++; -} - - -//----------------------------------------------------------------------------- -// Wait a certain time for tag response -// If a response is captured return TRUE -// If it takes to long return FALSE -//----------------------------------------------------------------------------- -static BOOL GetIso14443aAnswerFromTag(BYTE *receivedResponse, int maxLen, int *samples, int *elapsed) //BYTE *buffer -{ - // buffer needs to be 512 bytes - int c; - - // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen - // only, since we are receiving, not transmitting). - FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN); - - // Now get the answer from the card - Demod.output = receivedResponse; - Demod.len = 0; - Demod.state = DEMOD_UNSYNCD; - - BYTE b; - *elapsed = 0; - - c = 0; - for(;;) { - WDT_HIT(); - - if(SSC_STATUS & (SSC_STATUS_TX_READY)) { - SSC_TRANSMIT_HOLDING = 0x00; // To make use of exact timing of next command from reader!! - (*elapsed)++; - } - if(SSC_STATUS & (SSC_STATUS_RX_READY)) { - if(c < 512) { c++; } else { return FALSE; } - b = (BYTE)SSC_RECEIVE_HOLDING; - if(ManchesterDecoding((b & 0xf0) >> 4)) { - *samples = ((c - 1) << 3) + 4; - return TRUE; - } - if(ManchesterDecoding(b & 0x0f)) { - *samples = c << 3; - return TRUE; - } - } - } -} - -//----------------------------------------------------------------------------- -// Read an ISO 14443a tag. Send out commands and store answers. -// -//----------------------------------------------------------------------------- -void ReaderIso14443a(DWORD parameter) -{ - // Anticollision - static const BYTE cmd1[] = { 0x52 }; // or 0x26 - static const BYTE cmd2[] = { 0x93,0x20 }; - // UID = 0x2a,0x69,0x8d,0x43,0x8d, last two bytes are CRC bytes - BYTE cmd3[] = { 0x93,0x70,0x2a,0x69,0x8d,0x43,0x8d,0x52,0x55 }; - - // For Ultralight add an extra anticollission layer -> 95 20 and then 95 70 - - // greg - here we will add our cascade level 2 anticolission and select functions to deal with ultralight // and 7-byte UIDs in generall... - BYTE cmd4[] = {0x95,0x20}; // ask for cascade 2 select - // 95 20 - //BYTE cmd3a[] = { 0x95,0x70,0x2a,0x69,0x8d,0x43,0x8d,0x52,0x55 }; - // 95 70 - - // cascade 2 select - BYTE cmd5[] = { 0x95,0x70,0x2a,0x69,0x8d,0x43,0x8d,0x52,0x55 }; - - - // RATS (request for answer to select) - //BYTE cmd6[] = { 0xe0,0x50,0xbc,0xa5 }; // original RATS - BYTE cmd6[] = { 0xe0,0x21,0xb2,0xc7 }; // Desfire RATS - - int reqaddr = 2024; // was 2024 - tied to other size changes - int reqsize = 60; - - BYTE *req1 = (((BYTE *)BigBuf) + reqaddr); - int req1Len; - - BYTE *req2 = (((BYTE *)BigBuf) + reqaddr + reqsize); - int req2Len; - - BYTE *req3 = (((BYTE *)BigBuf) + reqaddr + (reqsize * 2)); - int req3Len; - -// greg added req 4 & 5 to deal with cascade 2 section - BYTE *req4 = (((BYTE *)BigBuf) + reqaddr + (reqsize * 3)); - int req4Len; - - BYTE *req5 = (((BYTE *)BigBuf) + reqaddr + (reqsize * 4)); - int req5Len; - - BYTE *req6 = (((BYTE *)BigBuf) + reqaddr + (reqsize * 5)); - int req6Len; - - //BYTE *req7 = (((BYTE *)BigBuf) + reqaddr + (reqsize * 6)); - //int req7Len; - - BYTE *receivedAnswer = (((BYTE *)BigBuf) + 3560); // was 3560 - tied to other size changes - - BYTE *trace = (BYTE *)BigBuf; - int traceLen = 0; - int rsamples = 0; - - memset(trace, 0x44, 2000); // was 2000 - tied to oter size chnages - // setting it to 3000 causes no tag responses to be detected (2900 is ok) - // setting it to 1000 causes no tag responses to be detected - - // Prepare some commands! - ShortFrameFromReader(cmd1); - memcpy(req1, ToSend, ToSendMax); req1Len = ToSendMax; - - CodeIso14443aAsReader(cmd2, sizeof(cmd2)); - memcpy(req2, ToSend, ToSendMax); req2Len = ToSendMax; - - CodeIso14443aAsReader(cmd3, sizeof(cmd3)); - memcpy(req3, ToSend, ToSendMax); req3Len = ToSendMax; - - - CodeIso14443aAsReader(cmd4, sizeof(cmd4)); // 4 is cascade 2 request - memcpy(req4, ToSend, ToSendMax); req4Len = ToSendMax; - - - CodeIso14443aAsReader(cmd5, sizeof(cmd5)); // 5 is cascade 2 select - memcpy(req5, ToSend, ToSendMax); req5Len = ToSendMax; - - - CodeIso14443aAsReader(cmd6, sizeof(cmd6)); - memcpy(req6, ToSend, ToSendMax); req6Len = ToSendMax; - - // Setup SSC - FpgaSetupSsc(); - - // Start from off (no field generated) - FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); - SpinDelay(200); - - SetAdcMuxFor(GPIO_MUXSEL_HIPKD); - FpgaSetupSsc(); - - // Now give it time to spin up. - FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD); - SpinDelay(200); - - LED_A_ON(); - LED_B_OFF(); - LED_C_OFF(); - LED_D_OFF(); - - int samples = 0; - int tsamples = 0; - int wait = 0; - int elapsed = 0; - - for(;;) { - // Send WUPA (or REQA) - TransmitFor14443a(req1, req1Len, &tsamples, &wait); - // Store answer in buffer - trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; - trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; - trace[traceLen++] = 1; - memcpy(trace+traceLen, cmd1, 1); - traceLen += 1; - if(traceLen > TRACE_LENGTH) goto done; - - while(!GetIso14443aAnswerFromTag(receivedAnswer, 100, &samples, &elapsed)) { - if(BUTTON_PRESS()) goto done; - - // No answer, just continue polling - TransmitFor14443a(req1, req1Len, &tsamples, &wait); - // Store answer in buffer - trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; - trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; - trace[traceLen++] = 1; - memcpy(trace+traceLen, cmd1, 1); - traceLen += 1; - if(traceLen > TRACE_LENGTH) goto done; - } - - // Store answer in buffer - rsamples = rsamples + (samples - Demod.samples); - trace[traceLen++] = ((rsamples >> 0) & 0xff); - trace[traceLen++] = ((rsamples >> 8) & 0xff); - trace[traceLen++] = ((rsamples >> 16) & 0xff); - trace[traceLen++] = 0x80 | ((rsamples >> 24) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 0) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 8) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 16) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 24) & 0xff); - trace[traceLen++] = Demod.len; - memcpy(trace+traceLen, receivedAnswer, Demod.len); - traceLen += Demod.len; - if(traceLen > TRACE_LENGTH) goto done; - - // Ask for card UID - TransmitFor14443a(req2, req2Len, &tsamples, &wait); - // Store answer in buffer - trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; - trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; - trace[traceLen++] = 2; - memcpy(trace+traceLen, cmd2, 2); - traceLen += 2; - if(traceLen > TRACE_LENGTH) goto done; - - if(!GetIso14443aAnswerFromTag(receivedAnswer, 100, &samples, &elapsed)) { - continue; - } - - // Store answer in buffer - rsamples = rsamples + (samples - Demod.samples); - trace[traceLen++] = ((rsamples >> 0) & 0xff); - trace[traceLen++] = ((rsamples >> 8) & 0xff); - trace[traceLen++] = ((rsamples >> 16) & 0xff); - trace[traceLen++] = 0x80 | ((rsamples >> 24) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 0) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 8) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 16) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 24) & 0xff); - trace[traceLen++] = Demod.len; - memcpy(trace+traceLen, receivedAnswer, Demod.len); - traceLen += Demod.len; - if(traceLen > TRACE_LENGTH) goto done; - - // Construct SELECT UID command - // First copy the 5 bytes (Mifare Classic) after the 93 70 - memcpy(cmd3+2,receivedAnswer,5); - // Secondly compute the two CRC bytes at the end - ComputeCrc14443(CRC_14443_A, cmd3, 7, &cmd3[7], &cmd3[8]); - // Prepare the bit sequence to modulate the subcarrier - // Store answer in buffer - trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; - trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; - trace[traceLen++] = 9; - memcpy(trace+traceLen, cmd3, 9); - traceLen += 9; - if(traceLen > TRACE_LENGTH) goto done; - CodeIso14443aAsReader(cmd3, sizeof(cmd3)); - memcpy(req3, ToSend, ToSendMax); req3Len = ToSendMax; - - // Select the card - TransmitFor14443a(req3, req3Len, &samples, &wait); - if(!GetIso14443aAnswerFromTag(receivedAnswer, 100, &samples, &elapsed)) { - continue; - } - - // Store answer in buffer - rsamples = rsamples + (samples - Demod.samples); - trace[traceLen++] = ((rsamples >> 0) & 0xff); - trace[traceLen++] = ((rsamples >> 8) & 0xff); - trace[traceLen++] = ((rsamples >> 16) & 0xff); - trace[traceLen++] = 0x80 | ((rsamples >> 24) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 0) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 8) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 16) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 24) & 0xff); - trace[traceLen++] = Demod.len; - memcpy(trace+traceLen, receivedAnswer, Demod.len); - traceLen += Demod.len; - if(traceLen > TRACE_LENGTH) goto done; - -// OK we have selected at least at cascade 1, lets see if first byte of UID was 0x88 in -// which case we need to make a cascade 2 request and select - this is a long UID - if (receivedAnswer[0] == 0x88) - { - // Do cascade level 2 stuff - /////////////////////////////////////////////////////////////////// - // First issue a '95 20' identify request - // Ask for card UID (part 2) - TransmitFor14443a(req4, req4Len, &tsamples, &wait); - // Store answer in buffer - trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; - trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; - trace[traceLen++] = 2; - memcpy(trace+traceLen, cmd4, 2); - traceLen += 2; - if(traceLen > TRACE_LENGTH) { - DbpString("Bugging out, just popped tracelength"); - goto done;} - - if(!GetIso14443aAnswerFromTag(receivedAnswer, 100, &samples, &elapsed)) { - continue; - } - // Store answer in buffer - rsamples = rsamples + (samples - Demod.samples); - trace[traceLen++] = ((rsamples >> 0) & 0xff); - trace[traceLen++] = ((rsamples >> 8) & 0xff); - trace[traceLen++] = ((rsamples >> 16) & 0xff); - trace[traceLen++] = 0x80 | ((rsamples >> 24) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 0) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 8) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 16) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 24) & 0xff); - trace[traceLen++] = Demod.len; - memcpy(trace+traceLen, receivedAnswer, Demod.len); - traceLen += Demod.len; - if(traceLen > TRACE_LENGTH) goto done; - ////////////////////////////////////////////////////////////////// - // Then Construct SELECT UID (cascasde 2) command - DbpString("Just about to copy the UID out of the cascade 2 id req"); - // First copy the 5 bytes (Mifare Classic) after the 95 70 - memcpy(cmd5+2,receivedAnswer,5); - // Secondly compute the two CRC bytes at the end - ComputeCrc14443(CRC_14443_A, cmd4, 7, &cmd5[7], &cmd5[8]); - // Prepare the bit sequence to modulate the subcarrier - // Store answer in buffer - trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; - trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; - trace[traceLen++] = 9; - memcpy(trace+traceLen, cmd5, 9); - traceLen += 9; - if(traceLen > TRACE_LENGTH) goto done; - CodeIso14443aAsReader(cmd5, sizeof(cmd5)); - memcpy(req5, ToSend, ToSendMax); req5Len = ToSendMax; - - // Select the card - TransmitFor14443a(req4, req4Len, &samples, &wait); - if(!GetIso14443aAnswerFromTag(receivedAnswer, 100, &samples, &elapsed)) { - continue; - } - - // Store answer in buffer - rsamples = rsamples + (samples - Demod.samples); - trace[traceLen++] = ((rsamples >> 0) & 0xff); - trace[traceLen++] = ((rsamples >> 8) & 0xff); - trace[traceLen++] = ((rsamples >> 16) & 0xff); - trace[traceLen++] = 0x80 | ((rsamples >> 24) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 0) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 8) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 16) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 24) & 0xff); - trace[traceLen++] = Demod.len; - memcpy(trace+traceLen, receivedAnswer, Demod.len); - traceLen += Demod.len; - if(traceLen > TRACE_LENGTH) goto done; - - - - - - - } - - - - // Secondly compute the two CRC bytes at the end - ComputeCrc14443(CRC_14443_A, cmd5, 2, &cmd5[2], &cmd5[3]); - // Send authentication request (Mifare Classic) - TransmitFor14443a(req5, req5Len, &samples, &wait); - trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; - trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; trace[traceLen++] = 0; - trace[traceLen++] = 4; - memcpy(trace+traceLen, cmd5, 4); - traceLen += 4; - if(traceLen > TRACE_LENGTH) goto done; - if(GetIso14443aAnswerFromTag(receivedAnswer, 100, &samples, &elapsed)) { - rsamples++; - // We received probably a random, continue and trace! - } - else { - // Received nothing - continue; - } - - // Trace the random, i'm curious - rsamples = rsamples + (samples - Demod.samples); - trace[traceLen++] = ((rsamples >> 0) & 0xff); - trace[traceLen++] = ((rsamples >> 8) & 0xff); - trace[traceLen++] = ((rsamples >> 16) & 0xff); - trace[traceLen++] = 0x80 | ((rsamples >> 24) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 0) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 8) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 16) & 0xff); - trace[traceLen++] = ((Demod.parityBits >> 24) & 0xff); - trace[traceLen++] = Demod.len; - memcpy(trace+traceLen, receivedAnswer, Demod.len); - traceLen += Demod.len; - if(traceLen > TRACE_LENGTH) goto done; - - // Thats it... - } - -done: - LED_A_OFF(); - LED_B_OFF(); - LED_C_OFF(); - LED_D_OFF(); - DbpIntegers(rsamples, 0xCC, 0xCC); - DbpString("ready.."); -} +//----------------------------------------------------------------------------- +// Merlok - June 2011, 2012 +// Gerhard de Koning Gans - May 2008 +// Hagen Fritsch - June 2010 +// +// 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. +//----------------------------------------------------------------------------- +// Routines to support ISO 14443 type A. +//----------------------------------------------------------------------------- + +#include "proxmark3.h" +#include "apps.h" +#include "util.h" +#include "string.h" +#include "cmd.h" + +#include "iso14443crc.h" +#include "iso14443a.h" +#include "crapto1.h" +#include "mifareutil.h" +#include "BigBuf.h" +static uint32_t iso14a_timeout; +int rsamples = 0; +uint8_t trigger = 0; +// the block number for the ISO14443-4 PCB +static uint8_t iso14_pcb_blocknum = 0; + +// +// ISO14443 timing: +// +// minimum time between the start bits of consecutive transfers from reader to tag: 7000 carrier (13.56Mhz) cycles +#define REQUEST_GUARD_TIME (7000/16 + 1) +// minimum time between last modulation of tag and next start bit from reader to tag: 1172 carrier cycles +#define FRAME_DELAY_TIME_PICC_TO_PCD (1172/16 + 1) +// bool LastCommandWasRequest = FALSE; + +// +// Total delays including SSC-Transfers between ARM and FPGA. These are in carrier clock cycles (1/13,56MHz) +// +// When the PM acts as reader and is receiving tag data, it takes +// 3 ticks delay in the AD converter +// 16 ticks until the modulation detector completes and sets curbit +// 8 ticks until bit_to_arm is assigned from curbit +// 8*16 ticks for the transfer from FPGA to ARM +// 4*16 ticks until we measure the time +// - 8*16 ticks because we measure the time of the previous transfer +#define DELAY_AIR2ARM_AS_READER (3 + 16 + 8 + 8*16 + 4*16 - 8*16) + +// When the PM acts as a reader and is sending, it takes +// 4*16 ticks until we can write data to the sending hold register +// 8*16 ticks until the SHR is transferred to the Sending Shift Register +// 8 ticks until the first transfer starts +// 8 ticks later the FPGA samples the data +// 1 tick to assign mod_sig_coil +#define DELAY_ARM2AIR_AS_READER (4*16 + 8*16 + 8 + 8 + 1) + +// When the PM acts as tag and is receiving it takes +// 2 ticks delay in the RF part (for the first falling edge), +// 3 ticks for the A/D conversion, +// 8 ticks on average until the start of the SSC transfer, +// 8 ticks until the SSC samples the first data +// 7*16 ticks to complete the transfer from FPGA to ARM +// 8 ticks until the next ssp_clk rising edge +// 4*16 ticks until we measure the time +// - 8*16 ticks because we measure the time of the previous transfer +#define DELAY_AIR2ARM_AS_TAG (2 + 3 + 8 + 8 + 7*16 + 8 + 4*16 - 8*16) + +// The FPGA will report its internal sending delay in +uint16_t FpgaSendQueueDelay; +// the 5 first bits are the number of bits buffered in mod_sig_buf +// the last three bits are the remaining ticks/2 after the mod_sig_buf shift +#define DELAY_FPGA_QUEUE (FpgaSendQueueDelay<<1) + +// When the PM acts as tag and is sending, it takes +// 4*16 ticks until we can write data to the sending hold register +// 8*16 ticks until the SHR is transferred to the Sending Shift Register +// 8 ticks until the first transfer starts +// 8 ticks later the FPGA samples the data +// + a varying number of ticks in the FPGA Delay Queue (mod_sig_buf) +// + 1 tick to assign mod_sig_coil +#define DELAY_ARM2AIR_AS_TAG (4*16 + 8*16 + 8 + 8 + DELAY_FPGA_QUEUE + 1) + +// When the PM acts as sniffer and is receiving tag data, it takes +// 3 ticks A/D conversion +// 14 ticks to complete the modulation detection +// 8 ticks (on average) until the result is stored in to_arm +// + the delays in transferring data - which is the same for +// sniffing reader and tag data and therefore not relevant +#define DELAY_TAG_AIR2ARM_AS_SNIFFER (3 + 14 + 8) + +// When the PM acts as sniffer and is receiving reader data, it takes +// 2 ticks delay in analogue RF receiver (for the falling edge of the +// start bit, which marks the start of the communication) +// 3 ticks A/D conversion +// 8 ticks on average until the data is stored in to_arm. +// + the delays in transferring data - which is the same for +// sniffing reader and tag data and therefore not relevant +#define DELAY_READER_AIR2ARM_AS_SNIFFER (2 + 3 + 8) + +//variables used for timing purposes: +//these are in ssp_clk cycles: +static uint32_t NextTransferTime; +static uint32_t LastTimeProxToAirStart; +static uint32_t LastProxToAirDuration; + + + +// CARD TO READER - manchester +// Sequence D: 11110000 modulation with subcarrier during first half +// Sequence E: 00001111 modulation with subcarrier during second half +// Sequence F: 00000000 no modulation with subcarrier +// READER TO CARD - miller +// Sequence X: 00001100 drop after half a period +// Sequence Y: 00000000 no drop +// Sequence Z: 11000000 drop at start +#define SEC_D 0xf0 +#define SEC_E 0x0f +#define SEC_F 0x00 +#define SEC_X 0x0c +#define SEC_Y 0x00 +#define SEC_Z 0xc0 + +const uint8_t OddByteParity[256] = { + 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, + 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, + 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, + 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, + 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, + 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, + 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, + 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, + 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, + 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, + 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, + 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, + 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1, + 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, + 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0, + 1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1 +}; + + +void iso14a_set_trigger(bool enable) { + trigger = enable; +} + + +void iso14a_set_timeout(uint32_t timeout) { + iso14a_timeout = timeout; + if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443A Timeout set to %ld (%dms)", iso14a_timeout, iso14a_timeout / 106); +} + + +void iso14a_set_ATS_timeout(uint8_t *ats) { + + uint8_t tb1; + uint8_t fwi; + uint32_t fwt; + + if (ats[0] > 1) { // there is a format byte T0 + if ((ats[1] & 0x20) == 0x20) { // there is an interface byte TB(1) + if ((ats[1] & 0x10) == 0x10) { // there is an interface byte TA(1) preceding TB(1) + tb1 = ats[3]; + } else { + tb1 = ats[2]; + } + fwi = (tb1 & 0xf0) >> 4; // frame waiting indicator (FWI) + fwt = 256 * 16 * (1 << fwi); // frame waiting time (FWT) in 1/fc + + iso14a_set_timeout(fwt/(8*16)); + } + } +} + + +//----------------------------------------------------------------------------- +// Generate the parity value for a byte sequence +// +//----------------------------------------------------------------------------- +byte_t oddparity (const byte_t bt) +{ + return OddByteParity[bt]; +} + +void GetParity(const uint8_t *pbtCmd, uint16_t iLen, uint8_t *par) +{ + uint16_t paritybit_cnt = 0; + uint16_t paritybyte_cnt = 0; + uint8_t parityBits = 0; + + for (uint16_t i = 0; i < iLen; i++) { + // Generate the parity bits + parityBits |= ((OddByteParity[pbtCmd[i]]) << (7-paritybit_cnt)); + if (paritybit_cnt == 7) { + par[paritybyte_cnt] = parityBits; // save 8 Bits parity + parityBits = 0; // and advance to next Parity Byte + paritybyte_cnt++; + paritybit_cnt = 0; + } else { + paritybit_cnt++; + } + } + + // save remaining parity bits + par[paritybyte_cnt] = parityBits; + +} + +void AppendCrc14443a(uint8_t* data, int len) +{ + ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1); +} + +//============================================================================= +// ISO 14443 Type A - Miller decoder +//============================================================================= +// Basics: +// This decoder is used when the PM3 acts as a tag. +// The reader will generate "pauses" by temporarily switching of the field. +// At the PM3 antenna we will therefore measure a modulated antenna voltage. +// The FPGA does a comparison with a threshold and would deliver e.g.: +// ........ 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1 ....... +// The Miller decoder needs to identify the following sequences: +// 2 (or 3) ticks pause followed by 6 (or 5) ticks unmodulated: pause at beginning - Sequence Z ("start of communication" or a "0") +// 8 ticks without a modulation: no pause - Sequence Y (a "0" or "end of communication" or "no information") +// 4 ticks unmodulated followed by 2 (or 3) ticks pause: pause in second half - Sequence X (a "1") +// Note 1: the bitstream may start at any time. We therefore need to sync. +// Note 2: the interpretation of Sequence Y and Z depends on the preceding sequence. +//----------------------------------------------------------------------------- +static tUart Uart; + +// Lookup-Table to decide if 4 raw bits are a modulation. +// We accept two or three consecutive "0" in any position with the rest "1" +const bool Mod_Miller_LUT[] = { + TRUE, TRUE, FALSE, TRUE, FALSE, FALSE, FALSE, FALSE, + TRUE, TRUE, FALSE, FALSE, TRUE, FALSE, FALSE, FALSE +}; +#define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x00F0) >> 4]) +#define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x000F)]) + +void UartReset() +{ + Uart.state = STATE_UNSYNCD; + Uart.bitCount = 0; + Uart.len = 0; // number of decoded data bytes + Uart.parityLen = 0; // number of decoded parity bytes + Uart.shiftReg = 0; // shiftreg to hold decoded data bits + Uart.parityBits = 0; // holds 8 parity bits + Uart.twoBits = 0x0000; // buffer for 2 Bits + Uart.highCnt = 0; + Uart.startTime = 0; + Uart.endTime = 0; +} + +void UartInit(uint8_t *data, uint8_t *parity) +{ + Uart.output = data; + Uart.parity = parity; + UartReset(); +} + +// use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time +static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time) +{ + + Uart.twoBits = (Uart.twoBits << 8) | bit; + + if (Uart.state == STATE_UNSYNCD) { // not yet synced + + if (Uart.highCnt < 2) { // wait for a stable unmodulated signal + if (Uart.twoBits == 0xffff) { + Uart.highCnt++; + } else { + Uart.highCnt = 0; + } + } else { + Uart.syncBit = 0xFFFF; // not set + // we look for a ...1111111100x11111xxxxxx pattern (the start bit) + if ((Uart.twoBits & 0xDF00) == 0x1F00) Uart.syncBit = 8; // mask is 11x11111 xxxxxxxx, + // check for 00x11111 xxxxxxxx + else if ((Uart.twoBits & 0xEF80) == 0x8F80) Uart.syncBit = 7; // both masks shifted right one bit, left padded with '1' + else if ((Uart.twoBits & 0xF7C0) == 0xC7C0) Uart.syncBit = 6; // ... + else if ((Uart.twoBits & 0xFBE0) == 0xE3E0) Uart.syncBit = 5; + else if ((Uart.twoBits & 0xFDF0) == 0xF1F0) Uart.syncBit = 4; + else if ((Uart.twoBits & 0xFEF8) == 0xF8F8) Uart.syncBit = 3; + else if ((Uart.twoBits & 0xFF7C) == 0xFC7C) Uart.syncBit = 2; + else if ((Uart.twoBits & 0xFFBE) == 0xFE3E) Uart.syncBit = 1; + if (Uart.syncBit != 0xFFFF) { // found a sync bit + Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8); + Uart.startTime -= Uart.syncBit; + Uart.endTime = Uart.startTime; + Uart.state = STATE_START_OF_COMMUNICATION; + } + } + + } else { + + if (IsMillerModulationNibble1(Uart.twoBits >> Uart.syncBit)) { + if (IsMillerModulationNibble2(Uart.twoBits >> Uart.syncBit)) { // Modulation in both halves - error + UartReset(); + } else { // Modulation in first half = Sequence Z = logic "0" + if (Uart.state == STATE_MILLER_X) { // error - must not follow after X + UartReset(); + } else { + Uart.bitCount++; + Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg + Uart.state = STATE_MILLER_Z; + Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 6; + if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity) + Uart.output[Uart.len++] = (Uart.shiftReg & 0xff); + Uart.parityBits <<= 1; // make room for the parity bit + Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit + Uart.bitCount = 0; + Uart.shiftReg = 0; + if((Uart.len&0x0007) == 0) { // every 8 data bytes + Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits + Uart.parityBits = 0; + } + } + } + } + } else { + if (IsMillerModulationNibble2(Uart.twoBits >> Uart.syncBit)) { // Modulation second half = Sequence X = logic "1" + Uart.bitCount++; + Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100; // add a 1 to the shiftreg + Uart.state = STATE_MILLER_X; + Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 2; + if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity) + Uart.output[Uart.len++] = (Uart.shiftReg & 0xff); + Uart.parityBits <<= 1; // make room for the new parity bit + Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit + Uart.bitCount = 0; + Uart.shiftReg = 0; + if ((Uart.len&0x0007) == 0) { // every 8 data bytes + Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits + Uart.parityBits = 0; + } + } + } else { // no modulation in both halves - Sequence Y + if (Uart.state == STATE_MILLER_Z || Uart.state == STATE_MILLER_Y) { // Y after logic "0" - End of Communication + Uart.state = STATE_UNSYNCD; + Uart.bitCount--; // last "0" was part of EOC sequence + Uart.shiftReg <<= 1; // drop it + if(Uart.bitCount > 0) { // if we decoded some bits + Uart.shiftReg >>= (9 - Uart.bitCount); // right align them + Uart.output[Uart.len++] = (Uart.shiftReg & 0xff); // add last byte to the output + Uart.parityBits <<= 1; // add a (void) parity bit + Uart.parityBits <<= (8 - (Uart.len&0x0007)); // left align parity bits + Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store it + return TRUE; + } else if (Uart.len & 0x0007) { // there are some parity bits to store + Uart.parityBits <<= (8 - (Uart.len&0x0007)); // left align remaining parity bits + Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store them + } + if (Uart.len) { + return TRUE; // we are finished with decoding the raw data sequence + } else { + UartReset(); // Nothing received - start over + Uart.highCnt = 1; + } + } + if (Uart.state == STATE_START_OF_COMMUNICATION) { // error - must not follow directly after SOC + UartReset(); + Uart.highCnt = 1; + } else { // a logic "0" + Uart.bitCount++; + Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg + Uart.state = STATE_MILLER_Y; + if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity) + Uart.output[Uart.len++] = (Uart.shiftReg & 0xff); + Uart.parityBits <<= 1; // make room for the parity bit + Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit + Uart.bitCount = 0; + Uart.shiftReg = 0; + if ((Uart.len&0x0007) == 0) { // every 8 data bytes + Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits + Uart.parityBits = 0; + } + } + } + } + } + + } + + return FALSE; // not finished yet, need more data +} + + + +//============================================================================= +// ISO 14443 Type A - Manchester decoder +//============================================================================= +// Basics: +// This decoder is used when the PM3 acts as a reader. +// The tag will modulate the reader field by asserting different loads to it. As a consequence, the voltage +// at the reader antenna will be modulated as well. The FPGA detects the modulation for us and would deliver e.g. the following: +// ........ 0 0 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 ....... +// The Manchester decoder needs to identify the following sequences: +// 4 ticks modulated followed by 4 ticks unmodulated: Sequence D = 1 (also used as "start of communication") +// 4 ticks unmodulated followed by 4 ticks modulated: Sequence E = 0 +// 8 ticks unmodulated: Sequence F = end of communication +// 8 ticks modulated: A collision. Save the collision position and treat as Sequence D +// Note 1: the bitstream may start at any time. We therefore need to sync. +// Note 2: parameter offset is used to determine the position of the parity bits (required for the anticollision command only) +static tDemod Demod; + +// Lookup-Table to decide if 4 raw bits are a modulation. +// We accept three or four "1" in any position +const bool Mod_Manchester_LUT[] = { + FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE, + FALSE, FALSE, FALSE, TRUE, FALSE, TRUE, TRUE, TRUE +}; + +#define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4]) +#define IsManchesterModulationNibble2(b) (Mod_Manchester_LUT[(b & 0x000F)]) + + +void DemodReset() +{ + Demod.state = DEMOD_UNSYNCD; + Demod.len = 0; // number of decoded data bytes + Demod.parityLen = 0; + Demod.shiftReg = 0; // shiftreg to hold decoded data bits + Demod.parityBits = 0; // + Demod.collisionPos = 0; // Position of collision bit + Demod.twoBits = 0xffff; // buffer for 2 Bits + Demod.highCnt = 0; + Demod.startTime = 0; + Demod.endTime = 0; +} + +void DemodInit(uint8_t *data, uint8_t *parity) +{ + Demod.output = data; + Demod.parity = parity; + DemodReset(); +} + +// use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time +static RAMFUNC int ManchesterDecoding(uint8_t bit, uint16_t offset, uint32_t non_real_time) +{ + + Demod.twoBits = (Demod.twoBits << 8) | bit; + + if (Demod.state == DEMOD_UNSYNCD) { + + if (Demod.highCnt < 2) { // wait for a stable unmodulated signal + if (Demod.twoBits == 0x0000) { + Demod.highCnt++; + } else { + Demod.highCnt = 0; + } + } else { + Demod.syncBit = 0xFFFF; // not set + if ((Demod.twoBits & 0x7700) == 0x7000) Demod.syncBit = 7; + else if ((Demod.twoBits & 0x3B80) == 0x3800) Demod.syncBit = 6; + else if ((Demod.twoBits & 0x1DC0) == 0x1C00) Demod.syncBit = 5; + else if ((Demod.twoBits & 0x0EE0) == 0x0E00) Demod.syncBit = 4; + else if ((Demod.twoBits & 0x0770) == 0x0700) Demod.syncBit = 3; + else if ((Demod.twoBits & 0x03B8) == 0x0380) Demod.syncBit = 2; + else if ((Demod.twoBits & 0x01DC) == 0x01C0) Demod.syncBit = 1; + else if ((Demod.twoBits & 0x00EE) == 0x00E0) Demod.syncBit = 0; + if (Demod.syncBit != 0xFFFF) { + Demod.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8); + Demod.startTime -= Demod.syncBit; + Demod.bitCount = offset; // number of decoded data bits + Demod.state = DEMOD_MANCHESTER_DATA; + } + } + + } else { + + if (IsManchesterModulationNibble1(Demod.twoBits >> Demod.syncBit)) { // modulation in first half + if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // ... and in second half = collision + if (!Demod.collisionPos) { + Demod.collisionPos = (Demod.len << 3) + Demod.bitCount; + } + } // modulation in first half only - Sequence D = 1 + Demod.bitCount++; + Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100; // in both cases, add a 1 to the shiftreg + if(Demod.bitCount == 9) { // if we decoded a full byte (including parity) + Demod.output[Demod.len++] = (Demod.shiftReg & 0xff); + Demod.parityBits <<= 1; // make room for the parity bit + Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit + Demod.bitCount = 0; + Demod.shiftReg = 0; + if((Demod.len&0x0007) == 0) { // every 8 data bytes + Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits + Demod.parityBits = 0; + } + } + Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1) - 4; + } else { // no modulation in first half + if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // and modulation in second half = Sequence E = 0 + Demod.bitCount++; + Demod.shiftReg = (Demod.shiftReg >> 1); // add a 0 to the shiftreg + if(Demod.bitCount >= 9) { // if we decoded a full byte (including parity) + Demod.output[Demod.len++] = (Demod.shiftReg & 0xff); + Demod.parityBits <<= 1; // make room for the new parity bit + Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit + Demod.bitCount = 0; + Demod.shiftReg = 0; + if ((Demod.len&0x0007) == 0) { // every 8 data bytes + Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits1 + Demod.parityBits = 0; + } + } + Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1); + } else { // no modulation in both halves - End of communication + if(Demod.bitCount > 0) { // there are some remaining data bits + Demod.shiftReg >>= (9 - Demod.bitCount); // right align the decoded bits + Demod.output[Demod.len++] = Demod.shiftReg & 0xff; // and add them to the output + Demod.parityBits <<= 1; // add a (void) parity bit + Demod.parityBits <<= (8 - (Demod.len&0x0007)); // left align remaining parity bits + Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them + return TRUE; + } else if (Demod.len & 0x0007) { // there are some parity bits to store + Demod.parityBits <<= (8 - (Demod.len&0x0007)); // left align remaining parity bits + Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them + } + if (Demod.len) { + return TRUE; // we are finished with decoding the raw data sequence + } else { // nothing received. Start over + DemodReset(); + } + } + } + + } + + return FALSE; // not finished yet, need more data +} + +//============================================================================= +// Finally, a `sniffer' for ISO 14443 Type A +// Both sides of communication! +//============================================================================= + +//----------------------------------------------------------------------------- +// Record the sequence of commands sent by the reader to the tag, with +// triggering so that we start recording at the point that the tag is moved +// near the reader. +//----------------------------------------------------------------------------- +void RAMFUNC SnoopIso14443a(uint8_t param) { + // param: + // bit 0 - trigger from first card answer + // bit 1 - trigger from first reader 7-bit request + + LEDsoff(); + + // We won't start recording the frames that we acquire until we trigger; + // a good trigger condition to get started is probably when we see a + // response from the tag. + // triggered == FALSE -- to wait first for card + bool triggered = !(param & 0x03); + + // Allocate memory from BigBuf for some buffers + // free all previous allocations first + BigBuf_free(); + + // The command (reader -> tag) that we're receiving. + uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE); + uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE); + + // The response (tag -> reader) that we're receiving. + uint8_t *receivedResponse = BigBuf_malloc(MAX_FRAME_SIZE); + uint8_t *receivedResponsePar = BigBuf_malloc(MAX_PARITY_SIZE); + + // The DMA buffer, used to stream samples from the FPGA + uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE); + + // init trace buffer + clear_trace(); + set_tracing(TRUE); + + uint8_t *data = dmaBuf; + uint8_t previous_data = 0; + int maxDataLen = 0; + int dataLen = 0; + bool TagIsActive = FALSE; + bool ReaderIsActive = FALSE; + + iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER); + + // Set up the demodulator for tag -> reader responses. + DemodInit(receivedResponse, receivedResponsePar); + + // Set up the demodulator for the reader -> tag commands + UartInit(receivedCmd, receivedCmdPar); + + // Setup and start DMA. + FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); + + // And now we loop, receiving samples. + for(uint32_t rsamples = 0; TRUE; ) { + + if(BUTTON_PRESS()) { + DbpString("cancelled by button"); + break; + } + + LED_A_ON(); + WDT_HIT(); + + int register readBufDataP = data - dmaBuf; + int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; + if (readBufDataP <= dmaBufDataP){ + dataLen = dmaBufDataP - readBufDataP; + } else { + dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; + } + // test for length of buffer + if(dataLen > maxDataLen) { + maxDataLen = dataLen; + if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) { + Dbprintf("blew circular buffer! dataLen=%d", dataLen); + break; + } + } + if(dataLen < 1) continue; + + // primary buffer was stopped( <-- we lost data! + if (!AT91C_BASE_PDC_SSC->PDC_RCR) { + AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf; + AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE; + Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary + } + // secondary buffer sets as primary, secondary buffer was stopped + if (!AT91C_BASE_PDC_SSC->PDC_RNCR) { + AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf; + AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE; + } + + LED_A_OFF(); + + if (rsamples & 0x01) { // Need two samples to feed Miller and Manchester-Decoder + + if(!TagIsActive) { // no need to try decoding reader data if the tag is sending + uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4); + if (MillerDecoding(readerdata, (rsamples-1)*4)) { + LED_C_ON(); + + // check - if there is a short 7bit request from reader + if ((!triggered) && (param & 0x02) && (Uart.len == 1) && (Uart.bitCount == 7)) triggered = TRUE; + + if(triggered) { + if (!LogTrace(receivedCmd, + Uart.len, + Uart.startTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER, + Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER, + Uart.parity, + TRUE)) break; + } + /* And ready to receive another command. */ + UartReset(); + /* And also reset the demod code, which might have been */ + /* false-triggered by the commands from the reader. */ + DemodReset(); + LED_B_OFF(); + } + ReaderIsActive = (Uart.state != STATE_UNSYNCD); + } + + if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending - and we cannot afford the time + uint8_t tagdata = (previous_data << 4) | (*data & 0x0F); + if(ManchesterDecoding(tagdata, 0, (rsamples-1)*4)) { + LED_B_ON(); + + if (!LogTrace(receivedResponse, + Demod.len, + Demod.startTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER, + Demod.endTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER, + Demod.parity, + FALSE)) break; + + if ((!triggered) && (param & 0x01)) triggered = TRUE; + + // And ready to receive another response. + DemodReset(); + LED_C_OFF(); + } + TagIsActive = (Demod.state != DEMOD_UNSYNCD); + } + } + + previous_data = *data; + rsamples++; + data++; + if(data == dmaBuf + DMA_BUFFER_SIZE) { + data = dmaBuf; + } + } // main cycle + + DbpString("COMMAND FINISHED"); + + FpgaDisableSscDma(); + Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len); + Dbprintf("traceLen=%d, Uart.output[0]=%08x", BigBuf_get_traceLen(), (uint32_t)Uart.output[0]); + LEDsoff(); +} + +//----------------------------------------------------------------------------- +// Prepare tag messages +//----------------------------------------------------------------------------- +static void CodeIso14443aAsTagPar(const uint8_t *cmd, uint16_t len, uint8_t *parity) +{ + ToSendReset(); + + // Correction bit, might be removed when not needed + ToSendStuffBit(0); + ToSendStuffBit(0); + ToSendStuffBit(0); + ToSendStuffBit(0); + ToSendStuffBit(1); // 1 + ToSendStuffBit(0); + ToSendStuffBit(0); + ToSendStuffBit(0); + + // Send startbit + ToSend[++ToSendMax] = SEC_D; + LastProxToAirDuration = 8 * ToSendMax - 4; + + for(uint16_t i = 0; i < len; i++) { + uint8_t b = cmd[i]; + + // Data bits + for(uint16_t j = 0; j < 8; j++) { + if(b & 1) { + ToSend[++ToSendMax] = SEC_D; + } else { + ToSend[++ToSendMax] = SEC_E; + } + b >>= 1; + } + + // Get the parity bit + if (parity[i>>3] & (0x80>>(i&0x0007))) { + ToSend[++ToSendMax] = SEC_D; + LastProxToAirDuration = 8 * ToSendMax - 4; + } else { + ToSend[++ToSendMax] = SEC_E; + LastProxToAirDuration = 8 * ToSendMax; + } + } + + // Send stopbit + ToSend[++ToSendMax] = SEC_F; + + // Convert from last byte pos to length + ToSendMax++; +} + +static void CodeIso14443aAsTag(const uint8_t *cmd, uint16_t len) +{ + uint8_t par[MAX_PARITY_SIZE]; + + GetParity(cmd, len, par); + CodeIso14443aAsTagPar(cmd, len, par); +} + + +static void Code4bitAnswerAsTag(uint8_t cmd) +{ + int i; + + ToSendReset(); + + // Correction bit, might be removed when not needed + ToSendStuffBit(0); + ToSendStuffBit(0); + ToSendStuffBit(0); + ToSendStuffBit(0); + ToSendStuffBit(1); // 1 + ToSendStuffBit(0); + ToSendStuffBit(0); + ToSendStuffBit(0); + + // Send startbit + ToSend[++ToSendMax] = SEC_D; + + uint8_t b = cmd; + for(i = 0; i < 4; i++) { + if(b & 1) { + ToSend[++ToSendMax] = SEC_D; + LastProxToAirDuration = 8 * ToSendMax - 4; + } else { + ToSend[++ToSendMax] = SEC_E; + LastProxToAirDuration = 8 * ToSendMax; + } + b >>= 1; + } + + // Send stopbit + ToSend[++ToSendMax] = SEC_F; + + // Convert from last byte pos to length + ToSendMax++; +} + +//----------------------------------------------------------------------------- +// Wait for commands from reader +// Stop when button is pressed +// Or return TRUE when command is captured +//----------------------------------------------------------------------------- +static int GetIso14443aCommandFromReader(uint8_t *received, uint8_t *parity, int *len) +{ + // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen + // only, since we are receiving, not transmitting). + // Signal field is off with the appropriate LED + LED_D_OFF(); + FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN); + + // Now run a `software UART' on the stream of incoming samples. + UartInit(received, parity); + + // clear RXRDY: + uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; + + for(;;) { + WDT_HIT(); + + if(BUTTON_PRESS()) return FALSE; + + if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { + b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; + if(MillerDecoding(b, 0)) { + *len = Uart.len; + return TRUE; + } + } + } +} + +static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded); +int EmSend4bitEx(uint8_t resp, bool correctionNeeded); +int EmSend4bit(uint8_t resp); +int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par); +int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded); +int EmSendCmd(uint8_t *resp, uint16_t respLen); +int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par); +bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity, + uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity); + +static uint8_t* free_buffer_pointer; + +typedef struct { + uint8_t* response; + size_t response_n; + uint8_t* modulation; + size_t modulation_n; + uint32_t ProxToAirDuration; +} tag_response_info_t; + +bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) { + // Example response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes + // This will need the following byte array for a modulation sequence + // 144 data bits (18 * 8) + // 18 parity bits + // 2 Start and stop + // 1 Correction bit (Answer in 1172 or 1236 periods, see FPGA) + // 1 just for the case + // ----------- + + // 166 bytes, since every bit that needs to be send costs us a byte + // + + + // Prepare the tag modulation bits from the message + CodeIso14443aAsTag(response_info->response,response_info->response_n); + + // Make sure we do not exceed the free buffer space + if (ToSendMax > max_buffer_size) { + Dbprintf("Out of memory, when modulating bits for tag answer:"); + Dbhexdump(response_info->response_n,response_info->response,false); + return false; + } + + // Copy the byte array, used for this modulation to the buffer position + memcpy(response_info->modulation,ToSend,ToSendMax); + + // Store the number of bytes that were used for encoding/modulation and the time needed to transfer them + response_info->modulation_n = ToSendMax; + response_info->ProxToAirDuration = LastProxToAirDuration; + + return true; +} + + +// "precompile" responses. There are 7 predefined responses with a total of 28 bytes data to transmit. +// Coded responses need one byte per bit to transfer (data, parity, start, stop, correction) +// 28 * 8 data bits, 28 * 1 parity bits, 7 start bits, 7 stop bits, 7 correction bits +// -> need 273 bytes buffer +#define ALLOCATED_TAG_MODULATION_BUFFER_SIZE 273 + +bool prepare_allocated_tag_modulation(tag_response_info_t* response_info) { + // Retrieve and store the current buffer index + response_info->modulation = free_buffer_pointer; + + // Determine the maximum size we can use from our buffer + size_t max_buffer_size = ALLOCATED_TAG_MODULATION_BUFFER_SIZE; + + // Forward the prepare tag modulation function to the inner function + if (prepare_tag_modulation(response_info, max_buffer_size)) { + // Update the free buffer offset + free_buffer_pointer += ToSendMax; + return true; + } else { + return false; + } +} + +//----------------------------------------------------------------------------- +// Main loop of simulated tag: receive commands from reader, decide what +// response to send, and send it. +//----------------------------------------------------------------------------- +void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data) +{ + uint8_t sak; + + // The first response contains the ATQA (note: bytes are transmitted in reverse order). + uint8_t response1[2]; + + switch (tagType) { + case 1: { // MIFARE Classic + // Says: I am Mifare 1k - original line + response1[0] = 0x04; + response1[1] = 0x00; + sak = 0x08; + } break; + case 2: { // MIFARE Ultralight + // Says: I am a stupid memory tag, no crypto + response1[0] = 0x04; + response1[1] = 0x00; + sak = 0x00; + } break; + case 3: { // MIFARE DESFire + // Says: I am a DESFire tag, ph33r me + response1[0] = 0x04; + response1[1] = 0x03; + sak = 0x20; + } break; + case 4: { // ISO/IEC 14443-4 + // Says: I am a javacard (JCOP) + response1[0] = 0x04; + response1[1] = 0x00; + sak = 0x28; + } break; + case 5: { // MIFARE TNP3XXX + // Says: I am a toy + response1[0] = 0x01; + response1[1] = 0x0f; + sak = 0x01; + } break; + default: { + Dbprintf("Error: unkown tagtype (%d)",tagType); + return; + } break; + } + + // The second response contains the (mandatory) first 24 bits of the UID + uint8_t response2[5] = {0x00}; + + // Check if the uid uses the (optional) part + uint8_t response2a[5] = {0x00}; + + if (uid_2nd) { + response2[0] = 0x88; + num_to_bytes(uid_1st,3,response2+1); + num_to_bytes(uid_2nd,4,response2a); + response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3]; + + // Configure the ATQA and SAK accordingly + response1[0] |= 0x40; + sak |= 0x04; + } else { + num_to_bytes(uid_1st,4,response2); + // Configure the ATQA and SAK accordingly + response1[0] &= 0xBF; + sak &= 0xFB; + } + + // Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID. + response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3]; + + // Prepare the mandatory SAK (for 4 and 7 byte UID) + uint8_t response3[3] = {0x00}; + response3[0] = sak; + ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]); + + // Prepare the optional second SAK (for 7 byte UID), drop the cascade bit + uint8_t response3a[3] = {0x00}; + response3a[0] = sak & 0xFB; + ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]); + + uint8_t response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce + uint8_t response6[] = { 0x04, 0x58, 0x80, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS: + // Format byte = 0x58: FSCI=0x08 (FSC=256), TA(1) and TC(1) present, + // TA(1) = 0x80: different divisors not supported, DR = 1, DS = 1 + // TB(1) = not present. Defaults: FWI = 4 (FWT = 256 * 16 * 2^4 * 1/fc = 4833us), SFGI = 0 (SFG = 256 * 16 * 2^0 * 1/fc = 302us) + // TC(1) = 0x02: CID supported, NAD not supported + ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]); + + #define TAG_RESPONSE_COUNT 7 + tag_response_info_t responses[TAG_RESPONSE_COUNT] = { + { .response = response1, .response_n = sizeof(response1) }, // Answer to request - respond with card type + { .response = response2, .response_n = sizeof(response2) }, // Anticollision cascade1 - respond with uid + { .response = response2a, .response_n = sizeof(response2a) }, // Anticollision cascade2 - respond with 2nd half of uid if asked + { .response = response3, .response_n = sizeof(response3) }, // Acknowledge select - cascade 1 + { .response = response3a, .response_n = sizeof(response3a) }, // Acknowledge select - cascade 2 + { .response = response5, .response_n = sizeof(response5) }, // Authentication answer (random nonce) + { .response = response6, .response_n = sizeof(response6) }, // dummy ATS (pseudo-ATR), answer to RATS + }; + + // Allocate 512 bytes for the dynamic modulation, created when the reader queries for it + // Such a response is less time critical, so we can prepare them on the fly + #define DYNAMIC_RESPONSE_BUFFER_SIZE 64 + #define DYNAMIC_MODULATION_BUFFER_SIZE 512 + uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE]; + uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE]; + tag_response_info_t dynamic_response_info = { + .response = dynamic_response_buffer, + .response_n = 0, + .modulation = dynamic_modulation_buffer, + .modulation_n = 0 + }; + + BigBuf_free_keep_EM(); + + // allocate buffers: + uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE); + uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE); + free_buffer_pointer = BigBuf_malloc(ALLOCATED_TAG_MODULATION_BUFFER_SIZE); + + // clear trace + clear_trace(); + set_tracing(TRUE); + + // Prepare the responses of the anticollision phase + // there will be not enough time to do this at the moment the reader sends it REQA + for (size_t i=0; i 0) { + // Copy the CID from the reader query + dynamic_response_info.response[1] = receivedCmd[1]; + + // Add CRC bytes, always used in ISO 14443A-4 compliant cards + AppendCrc14443a(dynamic_response_info.response,dynamic_response_info.response_n); + dynamic_response_info.response_n += 2; + + if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) { + Dbprintf("Error preparing tag response"); + if (tracing) { + LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); + } + break; + } + p_response = &dynamic_response_info; + } + } + + // Count number of wakeups received after a halt + if(order == 6 && lastorder == 5) { happened++; } + + // Count number of other messages after a halt + if(order != 6 && lastorder == 5) { happened2++; } + + if(cmdsRecvd > 999) { + DbpString("1000 commands later..."); + break; + } + cmdsRecvd++; + + if (p_response != NULL) { + EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52); + // do the tracing for the previous reader request and this tag answer: + uint8_t par[MAX_PARITY_SIZE]; + GetParity(p_response->response, p_response->response_n, par); + + EmLogTrace(Uart.output, + Uart.len, + Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, + Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, + Uart.parity, + p_response->response, + p_response->response_n, + LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG, + (LastTimeProxToAirStart + p_response->ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG, + par); + } + + if (!tracing) { + Dbprintf("Trace Full. Simulation stopped."); + break; + } + } + + Dbprintf("%x %x %x", happened, happened2, cmdsRecvd); + LED_A_OFF(); + BigBuf_free_keep_EM(); +} + + +// prepare a delayed transfer. This simply shifts ToSend[] by a number +// of bits specified in the delay parameter. +void PrepareDelayedTransfer(uint16_t delay) +{ + uint8_t bitmask = 0; + uint8_t bits_to_shift = 0; + uint8_t bits_shifted = 0; + + delay &= 0x07; + if (delay) { + for (uint16_t i = 0; i < delay; i++) { + bitmask |= (0x01 << i); + } + ToSend[ToSendMax++] = 0x00; + for (uint16_t i = 0; i < ToSendMax; i++) { + bits_to_shift = ToSend[i] & bitmask; + ToSend[i] = ToSend[i] >> delay; + ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay)); + bits_shifted = bits_to_shift; + } + } +} + + +//------------------------------------------------------------------------------------- +// Transmit the command (to the tag) that was placed in ToSend[]. +// Parameter timing: +// if NULL: transfer at next possible time, taking into account +// request guard time and frame delay time +// if == 0: transfer immediately and return time of transfer +// if != 0: delay transfer until time specified +//------------------------------------------------------------------------------------- +static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing) +{ + + FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD); + + uint32_t ThisTransferTime = 0; + + if (timing) { + if(*timing == 0) { // Measure time + *timing = (GetCountSspClk() + 8) & 0xfffffff8; + } else { + PrepareDelayedTransfer(*timing & 0x00000007); // Delay transfer (fine tuning - up to 7 MF clock ticks) + } + if(MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing"); + while(GetCountSspClk() < (*timing & 0xfffffff8)); // Delay transfer (multiple of 8 MF clock ticks) + LastTimeProxToAirStart = *timing; + } else { + ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8); + while(GetCountSspClk() < ThisTransferTime); + LastTimeProxToAirStart = ThisTransferTime; + } + + // clear TXRDY + AT91C_BASE_SSC->SSC_THR = SEC_Y; + + uint16_t c = 0; + for(;;) { + if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { + AT91C_BASE_SSC->SSC_THR = cmd[c]; + c++; + if(c >= len) { + break; + } + } + } + + NextTransferTime = MAX(NextTransferTime, LastTimeProxToAirStart + REQUEST_GUARD_TIME); +} + + +//----------------------------------------------------------------------------- +// Prepare reader command (in bits, support short frames) to send to FPGA +//----------------------------------------------------------------------------- +void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8_t *parity) +{ + int i, j; + int last; + uint8_t b; + + ToSendReset(); + + // Start of Communication (Seq. Z) + ToSend[++ToSendMax] = SEC_Z; + LastProxToAirDuration = 8 * (ToSendMax+1) - 6; + last = 0; + + size_t bytecount = nbytes(bits); + // Generate send structure for the data bits + for (i = 0; i < bytecount; i++) { + // Get the current byte to send + b = cmd[i]; + size_t bitsleft = MIN((bits-(i*8)),8); + + for (j = 0; j < bitsleft; j++) { + if (b & 1) { + // Sequence X + ToSend[++ToSendMax] = SEC_X; + LastProxToAirDuration = 8 * (ToSendMax+1) - 2; + last = 1; + } else { + if (last == 0) { + // Sequence Z + ToSend[++ToSendMax] = SEC_Z; + LastProxToAirDuration = 8 * (ToSendMax+1) - 6; + } else { + // Sequence Y + ToSend[++ToSendMax] = SEC_Y; + last = 0; + } + } + b >>= 1; + } + + // Only transmit parity bit if we transmitted a complete byte + if (j == 8) { + // Get the parity bit + if (parity[i>>3] & (0x80 >> (i&0x0007))) { + // Sequence X + ToSend[++ToSendMax] = SEC_X; + LastProxToAirDuration = 8 * (ToSendMax+1) - 2; + last = 1; + } else { + if (last == 0) { + // Sequence Z + ToSend[++ToSendMax] = SEC_Z; + LastProxToAirDuration = 8 * (ToSendMax+1) - 6; + } else { + // Sequence Y + ToSend[++ToSendMax] = SEC_Y; + last = 0; + } + } + } + } + + // End of Communication: Logic 0 followed by Sequence Y + if (last == 0) { + // Sequence Z + ToSend[++ToSendMax] = SEC_Z; + LastProxToAirDuration = 8 * (ToSendMax+1) - 6; + } else { + // Sequence Y + ToSend[++ToSendMax] = SEC_Y; + last = 0; + } + ToSend[++ToSendMax] = SEC_Y; + + // Convert to length of command: + ToSendMax++; +} + +//----------------------------------------------------------------------------- +// Prepare reader command to send to FPGA +//----------------------------------------------------------------------------- +void CodeIso14443aAsReaderPar(const uint8_t *cmd, uint16_t len, const uint8_t *parity) +{ + CodeIso14443aBitsAsReaderPar(cmd, len*8, parity); +} + + +//----------------------------------------------------------------------------- +// Wait for commands from reader +// Stop when button is pressed (return 1) or field was gone (return 2) +// Or return 0 when command is captured +//----------------------------------------------------------------------------- +static int EmGetCmd(uint8_t *received, uint16_t *len, uint8_t *parity) +{ + *len = 0; + + uint32_t timer = 0, vtime = 0; + int analogCnt = 0; + int analogAVG = 0; + + // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen + // only, since we are receiving, not transmitting). + // Signal field is off with the appropriate LED + LED_D_OFF(); + FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN); + + // Set ADC to read field strength + AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST; + AT91C_BASE_ADC->ADC_MR = + ADC_MODE_PRESCALE(63) | + ADC_MODE_STARTUP_TIME(1) | + ADC_MODE_SAMPLE_HOLD_TIME(15); + AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF); + // start ADC + AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START; + + // Now run a 'software UART' on the stream of incoming samples. + UartInit(received, parity); + + // Clear RXRDY: + uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; + + for(;;) { + WDT_HIT(); + + if (BUTTON_PRESS()) return 1; + + // test if the field exists + if (AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ADC_CHAN_HF)) { + analogCnt++; + analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF]; + AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START; + if (analogCnt >= 32) { + if ((MAX_ADC_HF_VOLTAGE * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) { + vtime = GetTickCount(); + if (!timer) timer = vtime; + // 50ms no field --> card to idle state + if (vtime - timer > 50) return 2; + } else + if (timer) timer = 0; + analogCnt = 0; + analogAVG = 0; + } + } + + // receive and test the miller decoding + if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { + b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; + if(MillerDecoding(b, 0)) { + *len = Uart.len; + return 0; + } + } + + } +} + + +static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded) +{ + uint8_t b; + uint16_t i = 0; + uint32_t ThisTransferTime; + + // Modulate Manchester + FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD); + + // include correction bit if necessary + if (Uart.parityBits & 0x01) { + correctionNeeded = TRUE; + } + if(correctionNeeded) { + // 1236, so correction bit needed + i = 0; + } else { + i = 1; + } + + // clear receiving shift register and holding register + while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY)); + b = AT91C_BASE_SSC->SSC_RHR; (void) b; + while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY)); + b = AT91C_BASE_SSC->SSC_RHR; (void) b; + + // wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line) + for (uint16_t j = 0; j < 5; j++) { // allow timeout - better late than never + while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY)); + if (AT91C_BASE_SSC->SSC_RHR) break; + } + + while ((ThisTransferTime = GetCountSspClk()) & 0x00000007); + + // Clear TXRDY: + AT91C_BASE_SSC->SSC_THR = SEC_F; + + // send cycle + for(; i < respLen; ) { + if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { + AT91C_BASE_SSC->SSC_THR = resp[i++]; + FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR; + } + + if(BUTTON_PRESS()) { + break; + } + } + + // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again: + uint8_t fpga_queued_bits = FpgaSendQueueDelay >> 3; + for (i = 0; i <= fpga_queued_bits/8 + 1; ) { + if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { + AT91C_BASE_SSC->SSC_THR = SEC_F; + FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR; + i++; + } + } + + LastTimeProxToAirStart = ThisTransferTime + (correctionNeeded?8:0); + + return 0; +} + +int EmSend4bitEx(uint8_t resp, bool correctionNeeded){ + Code4bitAnswerAsTag(resp); + int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded); + // do the tracing for the previous reader request and this tag answer: + uint8_t par[1]; + GetParity(&resp, 1, par); + EmLogTrace(Uart.output, + Uart.len, + Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, + Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, + Uart.parity, + &resp, + 1, + LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG, + (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG, + par); + return res; +} + +int EmSend4bit(uint8_t resp){ + return EmSend4bitEx(resp, false); +} + +int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par){ + CodeIso14443aAsTagPar(resp, respLen, par); + int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded); + // do the tracing for the previous reader request and this tag answer: + EmLogTrace(Uart.output, + Uart.len, + Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, + Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, + Uart.parity, + resp, + respLen, + LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG, + (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG, + par); + return res; +} + +int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded){ + uint8_t par[MAX_PARITY_SIZE]; + GetParity(resp, respLen, par); + return EmSendCmdExPar(resp, respLen, correctionNeeded, par); +} + +int EmSendCmd(uint8_t *resp, uint16_t respLen){ + uint8_t par[MAX_PARITY_SIZE]; + GetParity(resp, respLen, par); + return EmSendCmdExPar(resp, respLen, false, par); +} + +int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par){ + return EmSendCmdExPar(resp, respLen, false, par); +} + +bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity, + uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity) +{ + if (tracing) { + // we cannot exactly measure the end and start of a received command from reader. However we know that the delay from + // end of the received command to start of the tag's (simulated by us) answer is n*128+20 or n*128+84 resp. + // with n >= 9. The start of the tags answer can be measured and therefore the end of the received command be calculated: + uint16_t reader_modlen = reader_EndTime - reader_StartTime; + uint16_t approx_fdt = tag_StartTime - reader_EndTime; + uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20; + reader_EndTime = tag_StartTime - exact_fdt; + reader_StartTime = reader_EndTime - reader_modlen; + if (!LogTrace(reader_data, reader_len, reader_StartTime, reader_EndTime, reader_Parity, TRUE)) { + return FALSE; + } else return(!LogTrace(tag_data, tag_len, tag_StartTime, tag_EndTime, tag_Parity, FALSE)); + } else { + return TRUE; + } +} + +//----------------------------------------------------------------------------- +// Wait a certain time for tag response +// If a response is captured return TRUE +// If it takes too long return FALSE +//----------------------------------------------------------------------------- +static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receivedResponsePar, uint16_t offset) +{ + uint32_t c; + + // Set FPGA mode to "reader listen mode", no modulation (listen + // only, since we are receiving, not transmitting). + // Signal field is on with the appropriate LED + LED_D_ON(); + FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN); + + // Now get the answer from the card + DemodInit(receivedResponse, receivedResponsePar); + + // clear RXRDY: + uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; + + c = 0; + for(;;) { + WDT_HIT(); + + if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { + b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; + if(ManchesterDecoding(b, offset, 0)) { + NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD); + return TRUE; + } else if (c++ > iso14a_timeout && Demod.state == DEMOD_UNSYNCD) { + return FALSE; + } + } + } +} + +void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t *timing) +{ + CodeIso14443aBitsAsReaderPar(frame, bits, par); + + // Send command to tag + TransmitFor14443a(ToSend, ToSendMax, timing); + if(trigger) + LED_A_ON(); + + // Log reader command in trace buffer + if (tracing) { + LogTrace(frame, nbytes(bits), LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_READER, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_READER, par, TRUE); + } +} + +void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *timing) +{ + ReaderTransmitBitsPar(frame, len*8, par, timing); +} + +void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing) +{ + // Generate parity and redirect + uint8_t par[MAX_PARITY_SIZE]; + GetParity(frame, len/8, par); + ReaderTransmitBitsPar(frame, len, par, timing); +} + +void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *timing) +{ + // Generate parity and redirect + uint8_t par[MAX_PARITY_SIZE]; + GetParity(frame, len, par); + ReaderTransmitBitsPar(frame, len*8, par, timing); +} + +int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset, uint8_t *parity) +{ + if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, offset)) return FALSE; + if (tracing) { + LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE); + } + return Demod.len; +} + +int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity) +{ + if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, 0)) return FALSE; + if (tracing) { + LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE); + } + return Demod.len; +} + +/* performs iso14443a anticollision procedure + * fills the uid pointer unless NULL + * fills resp_data unless NULL */ +int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, uint32_t *cuid_ptr) { + uint8_t wupa[] = { 0x52 }; // 0x26 - REQA 0x52 - WAKE-UP + uint8_t sel_all[] = { 0x93,0x20 }; + uint8_t sel_uid[] = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00}; + uint8_t rats[] = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0 + uint8_t resp[MAX_FRAME_SIZE]; // theoretically. A usual RATS will be much smaller + uint8_t resp_par[MAX_PARITY_SIZE]; + byte_t uid_resp[4]; + size_t uid_resp_len; + + uint8_t sak = 0x04; // cascade uid + int cascade_level = 0; + int len; + + // Broadcast for a card, WUPA (0x52) will force response from all cards in the field + ReaderTransmitBitsPar(wupa,7,0, NULL); + + // Receive the ATQA + if(!ReaderReceive(resp, resp_par)) return 0; + + if(p_hi14a_card) { + memcpy(p_hi14a_card->atqa, resp, 2); + p_hi14a_card->uidlen = 0; + memset(p_hi14a_card->uid,0,10); + } + + // clear uid + if (uid_ptr) { + memset(uid_ptr,0,10); + } + + // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in + // which case we need to make a cascade 2 request and select - this is a long UID + // While the UID is not complete, the 3nd bit (from the right) is set in the SAK. + for(; sak & 0x04; cascade_level++) { + // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97) + sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2; + + // SELECT_ALL + ReaderTransmit(sel_all, sizeof(sel_all), NULL); + if (!ReaderReceive(resp, resp_par)) return 0; + + if (Demod.collisionPos) { // we had a collision and need to construct the UID bit by bit + memset(uid_resp, 0, 4); + uint16_t uid_resp_bits = 0; + uint16_t collision_answer_offset = 0; + // anti-collision-loop: + while (Demod.collisionPos) { + Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos); + for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) { // add valid UID bits before collision point + uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01; + uid_resp[uid_resp_bits / 8] |= UIDbit << (uid_resp_bits % 8); + } + uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8); // next time select the card(s) with a 1 in the collision position + uid_resp_bits++; + // construct anticollosion command: + sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07); // length of data in bytes and bits + for (uint16_t i = 0; i <= uid_resp_bits/8; i++) { + sel_uid[2+i] = uid_resp[i]; + } + collision_answer_offset = uid_resp_bits%8; + ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL); + if (!ReaderReceiveOffset(resp, collision_answer_offset, resp_par)) return 0; + } + // finally, add the last bits and BCC of the UID + for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) { + uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01; + uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8); + } + + } else { // no collision, use the response to SELECT_ALL as current uid + memcpy(uid_resp, resp, 4); + } + uid_resp_len = 4; + + // calculate crypto UID. Always use last 4 Bytes. + if(cuid_ptr) { + *cuid_ptr = bytes_to_num(uid_resp, 4); + } + + // Construct SELECT UID command + sel_uid[1] = 0x70; // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC) + memcpy(sel_uid+2, uid_resp, 4); // the UID + sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5]; // calculate and add BCC + AppendCrc14443a(sel_uid, 7); // calculate and add CRC + ReaderTransmit(sel_uid, sizeof(sel_uid), NULL); + + // Receive the SAK + if (!ReaderReceive(resp, resp_par)) return 0; + sak = resp[0]; + + // Test if more parts of the uid are coming + if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) { + // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of: + // http://www.nxp.com/documents/application_note/AN10927.pdf + uid_resp[0] = uid_resp[1]; + uid_resp[1] = uid_resp[2]; + uid_resp[2] = uid_resp[3]; + + uid_resp_len = 3; + } + + if(uid_ptr) { + memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len); + } + + if(p_hi14a_card) { + memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len); + p_hi14a_card->uidlen += uid_resp_len; + } + } + + if(p_hi14a_card) { + p_hi14a_card->sak = sak; + p_hi14a_card->ats_len = 0; + } + + // non iso14443a compliant tag + if( (sak & 0x20) == 0) return 2; + + // Request for answer to select + AppendCrc14443a(rats, 2); + ReaderTransmit(rats, sizeof(rats), NULL); + + if (!(len = ReaderReceive(resp, resp_par))) return 0; + + + if(p_hi14a_card) { + memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats)); + p_hi14a_card->ats_len = len; + } + + // reset the PCB block number + iso14_pcb_blocknum = 0; + + // set default timeout based on ATS + iso14a_set_ATS_timeout(resp); + + return 1; +} + +void iso14443a_setup(uint8_t fpga_minor_mode) { + FpgaDownloadAndGo(FPGA_BITSTREAM_HF); + // Set up the synchronous serial port + FpgaSetupSsc(); + // connect Demodulated Signal to ADC: + SetAdcMuxFor(GPIO_MUXSEL_HIPKD); + + // Signal field is on with the appropriate LED + if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD + || fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN) { + LED_D_ON(); + } else { + LED_D_OFF(); + } + FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode); + + // Start the timer + StartCountSspClk(); + + DemodReset(); + UartReset(); + NextTransferTime = 2*DELAY_ARM2AIR_AS_READER; + iso14a_set_timeout(1050); // 10ms default +} + +int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data) { + uint8_t parity[MAX_PARITY_SIZE]; + uint8_t real_cmd[cmd_len+4]; + real_cmd[0] = 0x0a; //I-Block + // put block number into the PCB + real_cmd[0] |= iso14_pcb_blocknum; + real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards + memcpy(real_cmd+2, cmd, cmd_len); + AppendCrc14443a(real_cmd,cmd_len+2); + + ReaderTransmit(real_cmd, cmd_len+4, NULL); + size_t len = ReaderReceive(data, parity); + uint8_t *data_bytes = (uint8_t *) data; + if (!len) + return 0; //DATA LINK ERROR + // if we received an I- or R(ACK)-Block with a block number equal to the + // current block number, toggle the current block number + else if (len >= 4 // PCB+CID+CRC = 4 bytes + && ((data_bytes[0] & 0xC0) == 0 // I-Block + || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0 + && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers + { + iso14_pcb_blocknum ^= 1; + } + + return len; +} + +//----------------------------------------------------------------------------- +// Read an ISO 14443a tag. Send out commands and store answers. +// +//----------------------------------------------------------------------------- +void ReaderIso14443a(UsbCommand *c) +{ + iso14a_command_t param = c->arg[0]; + uint8_t *cmd = c->d.asBytes; + size_t len = c->arg[1]; + size_t lenbits = c->arg[2]; + uint32_t arg0 = 0; + byte_t buf[USB_CMD_DATA_SIZE]; + uint8_t par[MAX_PARITY_SIZE]; + + if(param & ISO14A_CONNECT) { + clear_trace(); + } + + set_tracing(TRUE); + + if(param & ISO14A_REQUEST_TRIGGER) { + iso14a_set_trigger(TRUE); + } + + if(param & ISO14A_CONNECT) { + iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN); + if(!(param & ISO14A_NO_SELECT)) { + iso14a_card_select_t *card = (iso14a_card_select_t*)buf; + arg0 = iso14443a_select_card(NULL,card,NULL); + cmd_send(CMD_ACK,arg0,card->uidlen,0,buf,sizeof(iso14a_card_select_t)); + } + } + + if(param & ISO14A_SET_TIMEOUT) { + iso14a_set_timeout(c->arg[2]); + } + + if(param & ISO14A_APDU) { + arg0 = iso14_apdu(cmd, len, buf); + cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf)); + } + + if(param & ISO14A_RAW) { + if(param & ISO14A_APPEND_CRC) { + AppendCrc14443a(cmd,len); + len += 2; + if (lenbits) lenbits += 16; + } + if(lenbits>0) { + GetParity(cmd, lenbits/8, par); + ReaderTransmitBitsPar(cmd, lenbits, par, NULL); + } else { + ReaderTransmit(cmd,len, NULL); + } + arg0 = ReaderReceive(buf, par); + cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf)); + } + + if(param & ISO14A_REQUEST_TRIGGER) { + iso14a_set_trigger(FALSE); + } + + if(param & ISO14A_NO_DISCONNECT) { + return; + } + + FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); + LEDsoff(); +} + + +// Determine the distance between two nonces. +// Assume that the difference is small, but we don't know which is first. +// Therefore try in alternating directions. +int32_t dist_nt(uint32_t nt1, uint32_t nt2) { + + uint16_t i; + uint32_t nttmp1, nttmp2; + + if (nt1 == nt2) return 0; + + nttmp1 = nt1; + nttmp2 = nt2; + + for (i = 1; i < 32768; i++) { + nttmp1 = prng_successor(nttmp1, 1); + if (nttmp1 == nt2) return i; + nttmp2 = prng_successor(nttmp2, 1); + if (nttmp2 == nt1) return -i; + } + + return(-99999); // either nt1 or nt2 are invalid nonces +} + + +//----------------------------------------------------------------------------- +// Recover several bits of the cypher stream. This implements (first stages of) +// the algorithm described in "The Dark Side of Security by Obscurity and +// Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime" +// (article by Nicolas T. Courtois, 2009) +//----------------------------------------------------------------------------- +void ReaderMifare(bool first_try) +{ + // Mifare AUTH + uint8_t mf_auth[] = { 0x60,0x00,0xf5,0x7b }; + uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 }; + static uint8_t mf_nr_ar3; + + uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE]; + uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE]; + + // free eventually allocated BigBuf memory. We want all for tracing. + BigBuf_free(); + + clear_trace(); + set_tracing(TRUE); + + byte_t nt_diff = 0; + uint8_t par[1] = {0}; // maximum 8 Bytes to be sent here, 1 byte parity is therefore enough + static byte_t par_low = 0; + bool led_on = TRUE; + uint8_t uid[10] ={0}; + uint32_t cuid; + + uint32_t nt = 0; + uint32_t previous_nt = 0; + static uint32_t nt_attacked = 0; + byte_t par_list[8] = {0x00}; + byte_t ks_list[8] = {0x00}; + + static uint32_t sync_time; + static uint32_t sync_cycles; + int catch_up_cycles = 0; + int last_catch_up = 0; + uint16_t consecutive_resyncs = 0; + int isOK = 0; + + if (first_try) { + mf_nr_ar3 = 0; + iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD); + sync_time = GetCountSspClk() & 0xfffffff8; + sync_cycles = 65536; // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces). + nt_attacked = 0; + nt = 0; + par[0] = 0; + } + else { + // we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same) + mf_nr_ar3++; + mf_nr_ar[3] = mf_nr_ar3; + par[0] = par_low; + } + + LED_A_ON(); + LED_B_OFF(); + LED_C_OFF(); + + + for(uint16_t i = 0; TRUE; i++) { + + WDT_HIT(); + + // Test if the action was cancelled + if(BUTTON_PRESS()) { + break; + } + + LED_C_ON(); + + if(!iso14443a_select_card(uid, NULL, &cuid)) { + if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card"); + continue; + } + + sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles; + catch_up_cycles = 0; + + // if we missed the sync time already, advance to the next nonce repeat + while(GetCountSspClk() > sync_time) { + sync_time = (sync_time & 0xfffffff8) + sync_cycles; + } + + // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked) + ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time); + + // Receive the (4 Byte) "random" nonce + if (!ReaderReceive(receivedAnswer, receivedAnswerPar)) { + if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Couldn't receive tag nonce"); + continue; + } + + previous_nt = nt; + nt = bytes_to_num(receivedAnswer, 4); + + // Transmit reader nonce with fake par + ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL); + + if (first_try && previous_nt && !nt_attacked) { // we didn't calibrate our clock yet + int nt_distance = dist_nt(previous_nt, nt); + if (nt_distance == 0) { + nt_attacked = nt; + } + else { + if (nt_distance == -99999) { // invalid nonce received, try again + continue; + } + sync_cycles = (sync_cycles - nt_distance); + if (MF_DBGLEVEL >= 3) Dbprintf("calibrating in cycle %d. nt_distance=%d, Sync_cycles: %d\n", i, nt_distance, sync_cycles); + continue; + } + } + + if ((nt != nt_attacked) && nt_attacked) { // we somehow lost sync. Try to catch up again... + catch_up_cycles = -dist_nt(nt_attacked, nt); + if (catch_up_cycles == 99999) { // invalid nonce received. Don't resync on that one. + catch_up_cycles = 0; + continue; + } + if (catch_up_cycles == last_catch_up) { + consecutive_resyncs++; + } + else { + last_catch_up = catch_up_cycles; + consecutive_resyncs = 0; + } + if (consecutive_resyncs < 3) { + if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d. nt_distance=%d. Consecutive Resyncs = %d. Trying one time catch up...\n", i, -catch_up_cycles, consecutive_resyncs); + } + else { + sync_cycles = sync_cycles + catch_up_cycles; + if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d for the fourth time consecutively (nt_distance = %d). Adjusting sync_cycles to %d.\n", i, -catch_up_cycles, sync_cycles); + } + continue; + } + + consecutive_resyncs = 0; + + // Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding + if (ReaderReceive(receivedAnswer, receivedAnswerPar)) + { + catch_up_cycles = 8; // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer + + if (nt_diff == 0) + { + par_low = par[0] & 0xE0; // there is no need to check all parities for other nt_diff. Parity Bits for mf_nr_ar[0..2] won't change + } + + led_on = !led_on; + if(led_on) LED_B_ON(); else LED_B_OFF(); + + par_list[nt_diff] = SwapBits(par[0], 8); + ks_list[nt_diff] = receivedAnswer[0] ^ 0x05; + + // Test if the information is complete + if (nt_diff == 0x07) { + isOK = 1; + break; + } + + nt_diff = (nt_diff + 1) & 0x07; + mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5); + par[0] = par_low; + } else { + if (nt_diff == 0 && first_try) + { + par[0]++; + } else { + par[0] = ((par[0] & 0x1F) + 1) | par_low; + } + } + } + + + mf_nr_ar[3] &= 0x1F; + + byte_t buf[28]; + memcpy(buf + 0, uid, 4); + num_to_bytes(nt, 4, buf + 4); + memcpy(buf + 8, par_list, 8); + memcpy(buf + 16, ks_list, 8); + memcpy(buf + 24, mf_nr_ar, 4); + + cmd_send(CMD_ACK,isOK,0,0,buf,28); + + // Thats it... + FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); + LEDsoff(); + + set_tracing(FALSE); +} + +/** + *MIFARE 1K simulate. + * + *@param flags : + * FLAG_INTERACTIVE - In interactive mode, we are expected to finish the operation with an ACK + * 4B_FLAG_UID_IN_DATA - means that there is a 4-byte UID in the data-section, we're expected to use that + * 7B_FLAG_UID_IN_DATA - means that there is a 7-byte UID in the data-section, we're expected to use that + * FLAG_NR_AR_ATTACK - means we should collect NR_AR responses for bruteforcing later + *@param exitAfterNReads, exit simulation after n blocks have been read, 0 is inifite + */ +void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *datain) +{ + int cardSTATE = MFEMUL_NOFIELD; + int _7BUID = 0; + int vHf = 0; // in mV + int res; + uint32_t selTimer = 0; + uint32_t authTimer = 0; + uint16_t len = 0; + uint8_t cardWRBL = 0; + uint8_t cardAUTHSC = 0; + uint8_t cardAUTHKEY = 0xff; // no authentication + uint32_t cardRr = 0; + uint32_t cuid = 0; + //uint32_t rn_enc = 0; + uint32_t ans = 0; + uint32_t cardINTREG = 0; + uint8_t cardINTBLOCK = 0; + struct Crypto1State mpcs = {0, 0}; + struct Crypto1State *pcs; + pcs = &mpcs; + uint32_t numReads = 0;//Counts numer of times reader read a block + uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE]; + uint8_t receivedCmd_par[MAX_MIFARE_PARITY_SIZE]; + uint8_t response[MAX_MIFARE_FRAME_SIZE]; + uint8_t response_par[MAX_MIFARE_PARITY_SIZE]; + + uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID + uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; + uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; // !!! + uint8_t rSAK[] = {0x08, 0xb6, 0xdd}; + uint8_t rSAK1[] = {0x04, 0xda, 0x17}; + + uint8_t rAUTH_NT[] = {0x01, 0x02, 0x03, 0x04}; + uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00}; + + //Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2 + // This can be used in a reader-only attack. + // (it can also be retrieved via 'hf 14a list', but hey... + uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0}; + uint8_t ar_nr_collected = 0; + + // free eventually allocated BigBuf memory but keep Emulator Memory + BigBuf_free_keep_EM(); + + // clear trace + clear_trace(); + set_tracing(TRUE); + + // Authenticate response - nonce + uint32_t nonce = bytes_to_num(rAUTH_NT, 4); + + //-- Determine the UID + // Can be set from emulator memory, incoming data + // and can be 7 or 4 bytes long + if (flags & FLAG_4B_UID_IN_DATA) + { + // 4B uid comes from data-portion of packet + memcpy(rUIDBCC1,datain,4); + rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3]; + + } else if (flags & FLAG_7B_UID_IN_DATA) { + // 7B uid comes from data-portion of packet + memcpy(&rUIDBCC1[1],datain,3); + memcpy(rUIDBCC2, datain+3, 4); + _7BUID = true; + } else { + // get UID from emul memory + emlGetMemBt(receivedCmd, 7, 1); + _7BUID = !(receivedCmd[0] == 0x00); + if (!_7BUID) { // ---------- 4BUID + emlGetMemBt(rUIDBCC1, 0, 4); + } else { // ---------- 7BUID + emlGetMemBt(&rUIDBCC1[1], 0, 3); + emlGetMemBt(rUIDBCC2, 3, 4); + } + } + + /* + * Regardless of what method was used to set the UID, set fifth byte and modify + * the ATQA for 4 or 7-byte UID + */ + rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3]; + if (_7BUID) { + rATQA[0] = 0x44; + rUIDBCC1[0] = 0x88; + rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3]; + } + + // We need to listen to the high-frequency, peak-detected path. + iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN); + + + if (MF_DBGLEVEL >= 1) { + if (!_7BUID) { + Dbprintf("4B UID: %02x%02x%02x%02x", + rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3]); + } else { + Dbprintf("7B UID: (%02x)%02x%02x%02x%02x%02x%02x%02x", + rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3], + rUIDBCC2[0], rUIDBCC2[1] ,rUIDBCC2[2], rUIDBCC2[3]); + } + } + + bool finished = FALSE; + while (!BUTTON_PRESS() && !finished) { + WDT_HIT(); + + // find reader field + if (cardSTATE == MFEMUL_NOFIELD) { + vHf = (MAX_ADC_HF_VOLTAGE * AvgAdc(ADC_CHAN_HF)) >> 10; + if (vHf > MF_MINFIELDV) { + cardSTATE_TO_IDLE(); + LED_A_ON(); + } + } + if(cardSTATE == MFEMUL_NOFIELD) continue; + + //Now, get data + + res = EmGetCmd(receivedCmd, &len, receivedCmd_par); + if (res == 2) { //Field is off! + cardSTATE = MFEMUL_NOFIELD; + LEDsoff(); + continue; + } else if (res == 1) { + break; //return value 1 means button press + } + + // REQ or WUP request in ANY state and WUP in HALTED state + if (len == 1 && ((receivedCmd[0] == 0x26 && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == 0x52)) { + selTimer = GetTickCount(); + EmSendCmdEx(rATQA, sizeof(rATQA), (receivedCmd[0] == 0x52)); + cardSTATE = MFEMUL_SELECT1; + + // init crypto block + LED_B_OFF(); + LED_C_OFF(); + crypto1_destroy(pcs); + cardAUTHKEY = 0xff; + continue; + } + + switch (cardSTATE) { + case MFEMUL_NOFIELD: + case MFEMUL_HALTED: + case MFEMUL_IDLE:{ + LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); + break; + } + case MFEMUL_SELECT1:{ + // select all + if (len == 2 && (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x20)) { + if (MF_DBGLEVEL >= 4) Dbprintf("SELECT ALL received"); + EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1)); + break; + } + + if (MF_DBGLEVEL >= 4 && len == 9 && receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 ) + { + Dbprintf("SELECT %02x%02x%02x%02x received",receivedCmd[2],receivedCmd[3],receivedCmd[4],receivedCmd[5]); + } + // select card + if (len == 9 && + (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) { + EmSendCmd(_7BUID?rSAK1:rSAK, _7BUID?sizeof(rSAK1):sizeof(rSAK)); + cuid = bytes_to_num(rUIDBCC1, 4); + if (!_7BUID) { + cardSTATE = MFEMUL_WORK; + LED_B_ON(); + if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol1 time: %d", GetTickCount() - selTimer); + break; + } else { + cardSTATE = MFEMUL_SELECT2; + } + } + break; + } + case MFEMUL_AUTH1:{ + if( len != 8) + { + cardSTATE_TO_IDLE(); + LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); + break; + } + + uint32_t ar = bytes_to_num(receivedCmd, 4); + uint32_t nr = bytes_to_num(&receivedCmd[4], 4); + + //Collect AR/NR + if(ar_nr_collected < 2){ + if(ar_nr_responses[2] != ar) + {// Avoid duplicates... probably not necessary, ar should vary. + ar_nr_responses[ar_nr_collected*4] = cuid; + ar_nr_responses[ar_nr_collected*4+1] = nonce; + ar_nr_responses[ar_nr_collected*4+2] = ar; + ar_nr_responses[ar_nr_collected*4+3] = nr; + ar_nr_collected++; + } + } + + // --- crypto + crypto1_word(pcs, ar , 1); + cardRr = nr ^ crypto1_word(pcs, 0, 0); + + // test if auth OK + if (cardRr != prng_successor(nonce, 64)){ + if (MF_DBGLEVEL >= 2) Dbprintf("AUTH FAILED for sector %d with key %c. cardRr=%08x, succ=%08x", + cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B', + cardRr, prng_successor(nonce, 64)); + // Shouldn't we respond anything here? + // Right now, we don't nack or anything, which causes the + // reader to do a WUPA after a while. /Martin + // -- which is the correct response. /piwi + cardSTATE_TO_IDLE(); + LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); + break; + } + + ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0); + + num_to_bytes(ans, 4, rAUTH_AT); + // --- crypto + EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT)); + LED_C_ON(); + cardSTATE = MFEMUL_WORK; + if (MF_DBGLEVEL >= 4) Dbprintf("AUTH COMPLETED for sector %d with key %c. time=%d", + cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B', + GetTickCount() - authTimer); + break; + } + case MFEMUL_SELECT2:{ + if (!len) { + LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); + break; + } + if (len == 2 && (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x20)) { + EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2)); + break; + } + + // select 2 card + if (len == 9 && + (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0)) { + EmSendCmd(rSAK, sizeof(rSAK)); + cuid = bytes_to_num(rUIDBCC2, 4); + cardSTATE = MFEMUL_WORK; + LED_B_ON(); + if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol2 time: %d", GetTickCount() - selTimer); + break; + } + + // i guess there is a command). go into the work state. + if (len != 4) { + LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); + break; + } + cardSTATE = MFEMUL_WORK; + //goto lbWORK; + //intentional fall-through to the next case-stmt + } + + case MFEMUL_WORK:{ + if (len == 0) { + LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); + break; + } + + bool encrypted_data = (cardAUTHKEY != 0xFF) ; + + if(encrypted_data) { + // decrypt seqence + mf_crypto1_decrypt(pcs, receivedCmd, len); + } + + if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) { + authTimer = GetTickCount(); + cardAUTHSC = receivedCmd[1] / 4; // received block num + cardAUTHKEY = receivedCmd[0] - 0x60; + crypto1_destroy(pcs);//Added by martin + crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY)); + + if (!encrypted_data) { // first authentication + if (MF_DBGLEVEL >= 4) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY ); + + crypto1_word(pcs, cuid ^ nonce, 0);//Update crypto state + num_to_bytes(nonce, 4, rAUTH_AT); // Send nonce + } else { // nested authentication + if (MF_DBGLEVEL >= 4) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY ); + ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0); + num_to_bytes(ans, 4, rAUTH_AT); + } + + EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT)); + //Dbprintf("Sending rAUTH %02x%02x%02x%02x", rAUTH_AT[0],rAUTH_AT[1],rAUTH_AT[2],rAUTH_AT[3]); + cardSTATE = MFEMUL_AUTH1; + break; + } + + // rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued + // BUT... ACK --> NACK + if (len == 1 && receivedCmd[0] == CARD_ACK) { + EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); + break; + } + + // rule 12 of 7.5.3. in ISO 14443-4. R(NAK) --> R(ACK) + if (len == 1 && receivedCmd[0] == CARD_NACK_NA) { + EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK)); + break; + } + + if(len != 4) { + LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); + break; + } + + if(receivedCmd[0] == 0x30 // read block + || receivedCmd[0] == 0xA0 // write block + || receivedCmd[0] == 0xC0 // inc + || receivedCmd[0] == 0xC1 // dec + || receivedCmd[0] == 0xC2 // restore + || receivedCmd[0] == 0xB0) { // transfer + if (receivedCmd[1] >= 16 * 4) { + EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); + if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02) on out of range block: %d (0x%02x), nacking",receivedCmd[0],receivedCmd[1],receivedCmd[1]); + break; + } + + if (receivedCmd[1] / 4 != cardAUTHSC) { + EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); + if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02) on block (0x%02x) not authenticated for (0x%02x), nacking",receivedCmd[0],receivedCmd[1],cardAUTHSC); + break; + } + } + // read block + if (receivedCmd[0] == 0x30) { + if (MF_DBGLEVEL >= 4) { + Dbprintf("Reader reading block %d (0x%02x)",receivedCmd[1],receivedCmd[1]); + } + emlGetMem(response, receivedCmd[1], 1); + AppendCrc14443a(response, 16); + mf_crypto1_encrypt(pcs, response, 18, response_par); + EmSendCmdPar(response, 18, response_par); + numReads++; + if(exitAfterNReads > 0 && numReads == exitAfterNReads) { + Dbprintf("%d reads done, exiting", numReads); + finished = true; + } + break; + } + // write block + if (receivedCmd[0] == 0xA0) { + if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0xA0 write block %d (%02x)",receivedCmd[1],receivedCmd[1]); + EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK)); + cardSTATE = MFEMUL_WRITEBL2; + cardWRBL = receivedCmd[1]; + break; + } + // increment, decrement, restore + if (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2) { + if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]); + if (emlCheckValBl(receivedCmd[1])) { + if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking"); + EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); + break; + } + EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK)); + if (receivedCmd[0] == 0xC1) + cardSTATE = MFEMUL_INTREG_INC; + if (receivedCmd[0] == 0xC0) + cardSTATE = MFEMUL_INTREG_DEC; + if (receivedCmd[0] == 0xC2) + cardSTATE = MFEMUL_INTREG_REST; + cardWRBL = receivedCmd[1]; + break; + } + // transfer + if (receivedCmd[0] == 0xB0) { + if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x transfer block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]); + if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1])) + EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); + else + EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK)); + break; + } + // halt + if (receivedCmd[0] == 0x50 && receivedCmd[1] == 0x00) { + LED_B_OFF(); + LED_C_OFF(); + cardSTATE = MFEMUL_HALTED; + if (MF_DBGLEVEL >= 4) Dbprintf("--> HALTED. Selected time: %d ms", GetTickCount() - selTimer); + LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); + break; + } + // RATS + if (receivedCmd[0] == 0xe0) {//RATS + EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); + break; + } + // command not allowed + if (MF_DBGLEVEL >= 4) Dbprintf("Received command not allowed, nacking"); + EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); + break; + } + case MFEMUL_WRITEBL2:{ + if (len == 18){ + mf_crypto1_decrypt(pcs, receivedCmd, len); + emlSetMem(receivedCmd, cardWRBL, 1); + EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK)); + cardSTATE = MFEMUL_WORK; + } else { + cardSTATE_TO_IDLE(); + LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); + } + break; + } + + case MFEMUL_INTREG_INC:{ + mf_crypto1_decrypt(pcs, receivedCmd, len); + memcpy(&ans, receivedCmd, 4); + if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) { + EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); + cardSTATE_TO_IDLE(); + break; + } + LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); + cardINTREG = cardINTREG + ans; + cardSTATE = MFEMUL_WORK; + break; + } + case MFEMUL_INTREG_DEC:{ + mf_crypto1_decrypt(pcs, receivedCmd, len); + memcpy(&ans, receivedCmd, 4); + if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) { + EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); + cardSTATE_TO_IDLE(); + break; + } + LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); + cardINTREG = cardINTREG - ans; + cardSTATE = MFEMUL_WORK; + break; + } + case MFEMUL_INTREG_REST:{ + mf_crypto1_decrypt(pcs, receivedCmd, len); + memcpy(&ans, receivedCmd, 4); + if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) { + EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); + cardSTATE_TO_IDLE(); + break; + } + LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE); + cardSTATE = MFEMUL_WORK; + break; + } + } + } + + FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); + LEDsoff(); + + if(flags & FLAG_INTERACTIVE)// Interactive mode flag, means we need to send ACK + { + //May just aswell send the collected ar_nr in the response aswell + cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,0,0,&ar_nr_responses,ar_nr_collected*4*4); + } + + if(flags & FLAG_NR_AR_ATTACK) + { + if(ar_nr_collected > 1) { + Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:"); + Dbprintf("../tools/mfkey/mfkey32 %08x %08x %08x %08x %08x %08x", + ar_nr_responses[0], // UID + ar_nr_responses[1], //NT + ar_nr_responses[2], //AR1 + ar_nr_responses[3], //NR1 + ar_nr_responses[6], //AR2 + ar_nr_responses[7] //NR2 + ); + } else { + Dbprintf("Failed to obtain two AR/NR pairs!"); + if(ar_nr_collected >0) { + Dbprintf("Only got these: UID=%08x, nonce=%08x, AR1=%08x, NR1=%08x", + ar_nr_responses[0], // UID + ar_nr_responses[1], //NT + ar_nr_responses[2], //AR1 + ar_nr_responses[3] //NR1 + ); + } + } + } + if (MF_DBGLEVEL >= 1) Dbprintf("Emulator stopped. Tracing: %d trace length: %d ", tracing, BigBuf_get_traceLen()); + +} + + + +//----------------------------------------------------------------------------- +// MIFARE sniffer. +// +//----------------------------------------------------------------------------- +void RAMFUNC SniffMifare(uint8_t param) { + // param: + // bit 0 - trigger from first card answer + // bit 1 - trigger from first reader 7-bit request + + // C(red) A(yellow) B(green) + LEDsoff(); + // init trace buffer + clear_trace(); + set_tracing(TRUE); + + // The command (reader -> tag) that we're receiving. + // The length of a received command will in most cases be no more than 18 bytes. + // So 32 should be enough! + uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE]; + uint8_t receivedCmdPar[MAX_MIFARE_PARITY_SIZE]; + // The response (tag -> reader) that we're receiving. + uint8_t receivedResponse[MAX_MIFARE_FRAME_SIZE]; + uint8_t receivedResponsePar[MAX_MIFARE_PARITY_SIZE]; + + // As we receive stuff, we copy it from receivedCmd or receivedResponse + // into trace, along with its length and other annotations. + //uint8_t *trace = (uint8_t *)BigBuf; + + // free eventually allocated BigBuf memory + BigBuf_free(); + // allocate the DMA buffer, used to stream samples from the FPGA + uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE); + uint8_t *data = dmaBuf; + uint8_t previous_data = 0; + int maxDataLen = 0; + int dataLen = 0; + bool ReaderIsActive = FALSE; + bool TagIsActive = FALSE; + + iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER); + + // Set up the demodulator for tag -> reader responses. + DemodInit(receivedResponse, receivedResponsePar); + + // Set up the demodulator for the reader -> tag commands + UartInit(receivedCmd, receivedCmdPar); + + // Setup for the DMA. + FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer. + + LED_D_OFF(); + + // init sniffer + MfSniffInit(); + + // And now we loop, receiving samples. + for(uint32_t sniffCounter = 0; TRUE; ) { + + if(BUTTON_PRESS()) { + DbpString("cancelled by button"); + break; + } + + LED_A_ON(); + WDT_HIT(); + + if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time + // check if a transaction is completed (timeout after 2000ms). + // if yes, stop the DMA transfer and send what we have so far to the client + if (MfSniffSend(2000)) { + // Reset everything - we missed some sniffed data anyway while the DMA was stopped + sniffCounter = 0; + data = dmaBuf; + maxDataLen = 0; + ReaderIsActive = FALSE; + TagIsActive = FALSE; + FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer. + } + } + + int register readBufDataP = data - dmaBuf; // number of bytes we have processed so far + int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred + if (readBufDataP <= dmaBufDataP){ // we are processing the same block of data which is currently being transferred + dataLen = dmaBufDataP - readBufDataP; // number of bytes still to be processed + } else { + dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed + } + // test for length of buffer + if(dataLen > maxDataLen) { // we are more behind than ever... + maxDataLen = dataLen; + if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) { + Dbprintf("blew circular buffer! dataLen=0x%x", dataLen); + break; + } + } + if(dataLen < 1) continue; + + // primary buffer was stopped ( <-- we lost data! + if (!AT91C_BASE_PDC_SSC->PDC_RCR) { + AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf; + AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE; + Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary + } + // secondary buffer sets as primary, secondary buffer was stopped + if (!AT91C_BASE_PDC_SSC->PDC_RNCR) { + AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf; + AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE; + } + + LED_A_OFF(); + + if (sniffCounter & 0x01) { + + if(!TagIsActive) { // no need to try decoding tag data if the reader is sending + uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4); + if(MillerDecoding(readerdata, (sniffCounter-1)*4)) { + LED_C_INV(); + if (MfSniffLogic(receivedCmd, Uart.len, Uart.parity, Uart.bitCount, TRUE)) break; + + /* And ready to receive another command. */ + UartReset(); + + /* And also reset the demod code */ + DemodReset(); + } + ReaderIsActive = (Uart.state != STATE_UNSYNCD); + } + + if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending + uint8_t tagdata = (previous_data << 4) | (*data & 0x0F); + if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) { + LED_C_INV(); + + if (MfSniffLogic(receivedResponse, Demod.len, Demod.parity, Demod.bitCount, FALSE)) break; + + // And ready to receive another response. + DemodReset(); + } + TagIsActive = (Demod.state != DEMOD_UNSYNCD); + } + } + + previous_data = *data; + sniffCounter++; + data++; + if(data == dmaBuf + DMA_BUFFER_SIZE) { + data = dmaBuf; + } + + } // main cycle + + DbpString("COMMAND FINISHED"); + + FpgaDisableSscDma(); + MfSniffEnd(); + + Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len); + LEDsoff(); +}