X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/2b1f4228c2987459445d30443f92038f9ea080c6..4c0cf2d215529456c239b921b082ebb1a56bb98a:/armsrc/iso14443a.c diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c index bfbc70c7..8dbe9e81 100644 --- a/armsrc/iso14443a.c +++ b/armsrc/iso14443a.c @@ -106,8 +106,6 @@ 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 @@ -127,13 +125,11 @@ 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; @@ -142,20 +138,22 @@ void iso14a_set_ATS_timeout(uint8_t *ats) { 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) + + if ((ats[1] & 0x10) == 0x10) // there is an interface byte TA(1) preceding TB(1) tb1 = ats[3]; - } else { + else tb1 = ats[2]; - } + fwi = (tb1 & 0xf0) >> 4; // frame waiting indicator (FWI) - fwt = 256 * 16 * (1 << fwi); // frame waiting time (FWT) in 1/fc + //fwt = 256 * 16 * (1 << fwi); // frame waiting time (FWT) in 1/fc + fwt = 4096 * (1 << fwi); - iso14a_set_timeout(fwt/(8*16)); + //iso14a_set_timeout(fwt/(8*16)); + iso14a_set_timeout(fwt/128); } } } - //----------------------------------------------------------------------------- // Generate the parity value for a byte sequence // @@ -1059,10 +1057,12 @@ void SimulateIso14443aTag(int tagType, int flags, byte_t* data) { .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 + + { .response = response8, .response_n = sizeof(response8) } // EV1/NTAG PACK response + }; //{ .response = response7_NTAG, .response_n = sizeof(response7_NTAG)}, // EV1/NTAG GET_VERSION response - { .response = response8, .response_n = sizeof(response8) }, // EV1/NTAG PACK response //{ .response = response9, .response_n = sizeof(response9) } // EV1/NTAG CHK_TEAR response - }; + // 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 @@ -1093,9 +1093,8 @@ void SimulateIso14443aTag(int tagType, int flags, byte_t* data) // 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; imodulation, 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]; + uint8_t par[MAX_PARITY_SIZE] = {0x00}; GetParity(p_response->response, p_response->response_n, par); EmLogTrace(Uart.output, @@ -1444,7 +1437,7 @@ void PrepareDelayedTransfer(uint16_t delay) for (uint16_t i = 0; i < delay; i++) { bitmask |= (0x01 << i); } - ToSend[ToSendMax++] = 0x00; + ToSend[++ToSendMax] = 0x00; for (uint16_t i = 0; i < ToSendMax; i++) { bits_to_shift = ToSend[i] & bitmask; ToSend[i] = ToSend[i] >> delay; @@ -1465,7 +1458,6 @@ void PrepareDelayedTransfer(uint16_t delay) //------------------------------------------------------------------------------------- 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; @@ -1477,6 +1469,7 @@ static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing 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 { @@ -1492,10 +1485,9 @@ static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing for(;;) { if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { AT91C_BASE_SSC->SSC_THR = cmd[c]; - c++; - if(c >= len) { + ++c; + if(c >= len) break; - } } } @@ -1509,7 +1501,7 @@ static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8_t *parity) { int i, j; - int last; + int last = 0; uint8_t b; ToSendReset(); @@ -1517,7 +1509,6 @@ void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8 // 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 @@ -1730,7 +1721,7 @@ 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]; + uint8_t par[1] = {0x00}; GetParity(&resp, 1, par); EmLogTrace(Uart.output, Uart.len, @@ -1767,13 +1758,13 @@ int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8 } int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded){ - uint8_t par[MAX_PARITY_SIZE]; + uint8_t par[MAX_PARITY_SIZE] = {0x00}; GetParity(resp, respLen, par); return EmSendCmdExPar(resp, respLen, correctionNeeded, par); } int EmSendCmd(uint8_t *resp, uint16_t respLen){ - uint8_t par[MAX_PARITY_SIZE]; + uint8_t par[MAX_PARITY_SIZE] = {0x00}; GetParity(resp, respLen, par); return EmSendCmdExPar(resp, respLen, false, par); } @@ -1785,21 +1776,20 @@ 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) { - 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; - } + // 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)); + } //----------------------------------------------------------------------------- @@ -1848,9 +1838,7 @@ void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t 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); - } + 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) @@ -1861,7 +1849,7 @@ void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *tim void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing) { // Generate parity and redirect - uint8_t par[MAX_PARITY_SIZE]; + uint8_t par[MAX_PARITY_SIZE] = {0x00}; GetParity(frame, len/8, par); ReaderTransmitBitsPar(frame, len, par, timing); } @@ -1869,26 +1857,26 @@ void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing) void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *timing) { // Generate parity and redirect - uint8_t par[MAX_PARITY_SIZE]; + uint8_t par[MAX_PARITY_SIZE] = {0x00}; 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); - } + if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, offset)) + return FALSE; + + 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); - } + if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, 0)) + return FALSE; + + LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE); return Demod.len; } @@ -1902,10 +1890,10 @@ int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, u 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 resp[MAX_FRAME_SIZE] = {0}; // theoretically. A usual RATS will be much smaller + uint8_t resp_par[MAX_PARITY_SIZE] = {0}; + byte_t uid_resp[4] = {0}; + size_t uid_resp_len = 0; uint8_t sak = 0x04; // cascade uid int cascade_level = 0; @@ -1924,16 +1912,13 @@ int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, u } if (anticollision) { - // clear uid - if (uid_ptr) { - memset(uid_ptr,0,10); - } + // clear uid + if (uid_ptr) + memset(uid_ptr,0,10); } // check for proprietary anticollision: - if ((resp[0] & 0x1F) == 0) { - return 3; - } + if ((resp[0] & 0x1F) == 0) return 3; // 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 @@ -1944,40 +1929,41 @@ int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, u if (anticollision) { // 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); + 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; } - 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]; + // 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); } - 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); - } + } else { // no collision, use the response to SELECT_ALL as current uid + memcpy(uid_resp, resp, 4); + } + } else { if (cascade_level < num_cascades - 1) { uid_resp[0] = 0x88; @@ -1989,9 +1975,8 @@ int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, u uid_resp_len = 4; // calculate crypto UID. Always use last 4 Bytes. - if(cuid_ptr) { + 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) @@ -2002,9 +1987,10 @@ int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, u // Receive the SAK if (!ReaderReceive(resp, resp_par)) return 0; + sak = resp[0]; - // Test if more parts of the uid are coming + // 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 @@ -2014,9 +2000,8 @@ int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, u uid_resp_len = 3; } - if(uid_ptr && anticollision) { + if(uid_ptr && anticollision) 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); @@ -2037,7 +2022,6 @@ int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, u 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)); @@ -2079,7 +2063,7 @@ void iso14443a_setup(uint8_t fpga_minor_mode) { } int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data) { - uint8_t parity[MAX_PARITY_SIZE]; + uint8_t parity[MAX_PARITY_SIZE] = {0x00}; uint8_t real_cmd[cmd_len+4]; real_cmd[0] = 0x0a; //I-Block // put block number into the PCB @@ -2118,20 +2102,19 @@ void ReaderIso14443a(UsbCommand *c) size_t lenbits = c->arg[1] >> 16; uint32_t timeout = c->arg[2]; uint32_t arg0 = 0; - byte_t buf[USB_CMD_DATA_SIZE]; - uint8_t par[MAX_PARITY_SIZE]; + byte_t buf[USB_CMD_DATA_SIZE] = {0x00}; + uint8_t par[MAX_PARITY_SIZE] = {0x00}; - if(param & ISO14A_CONNECT) { + if (param & ISO14A_CONNECT) clear_trace(); - } set_tracing(TRUE); - if(param & ISO14A_REQUEST_TRIGGER) { + if (param & ISO14A_REQUEST_TRIGGER) iso14a_set_trigger(TRUE); - } - if(param & ISO14A_CONNECT) { + + 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; @@ -2140,16 +2123,15 @@ void ReaderIso14443a(UsbCommand *c) } } - if(param & ISO14A_SET_TIMEOUT) { + if (param & ISO14A_SET_TIMEOUT) iso14a_set_timeout(timeout); - } - if(param & ISO14A_APDU) { + 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_RAW) { if(param & ISO14A_APPEND_CRC) { if(param & ISO14A_TOPAZMODE) { AppendCrc14443b(cmd,len); @@ -2188,13 +2170,12 @@ void ReaderIso14443a(UsbCommand *c) cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf)); } - if(param & ISO14A_REQUEST_TRIGGER) { + if (param & ISO14A_REQUEST_TRIGGER) iso14a_set_trigger(FALSE); - } - if(param & ISO14A_NO_DISCONNECT) { + + if (param & ISO14A_NO_DISCONNECT) return; - } FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); set_tracing(FALSE); @@ -2207,20 +2188,19 @@ void ReaderIso14443a(UsbCommand *c) // 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 < 0xFFFF; i++) { + uint16_t i; + uint32_t nttmp1 = nt1; + uint32_t nttmp2 = nt2; + + for (i = 1; i < 0xFFFF; ++i) { nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i; + nttmp2 = prng_successor(nttmp2, 1); - if (nttmp2 == nt1) return -i; - } + if (nttmp2 == nt1) return -i; + } return(-99999); // either nt1 or nt2 are invalid nonces } @@ -2232,32 +2212,27 @@ int32_t dist_nt(uint32_t nt1, uint32_t nt2) { // Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime" // (article by Nicolas T. Courtois, 2009) //----------------------------------------------------------------------------- -void ReaderMifare(bool first_try) +void ReaderMifare(bool first_try, uint8_t block ) { // Mifare AUTH - uint8_t mf_auth[] = { 0x60,0x00,0xf5,0x7b }; + //uint8_t mf_auth[] = { 0x60,0x00,0xf5,0x7b }; + //uint8_t mf_auth[] = { 0x60,0x05, 0x58, 0x2c }; + uint8_t mf_auth[] = { 0x60,0x00, 0x00, 0x00 }; uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 }; - static uint8_t mf_nr_ar3; + static uint8_t mf_nr_ar3 = 0; - uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE]; - uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE]; - - if (first_try) { - iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD); - } + mf_auth[1] = block; + AppendCrc14443a(mf_auth, 2); - // free eventually allocated BigBuf memory. We want all for tracing. - BigBuf_free(); - - clear_trace(); - set_tracing(TRUE); + uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE] = {0x00}; + uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE] = {0x00}; 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; + uint8_t uid[10] = {0}; + uint32_t cuid = 0; uint32_t nt = 0; uint32_t previous_nt = 0; @@ -2265,49 +2240,62 @@ void ReaderMifare(bool first_try) byte_t par_list[8] = {0x00}; byte_t ks_list[8] = {0x00}; - #define PRNG_SEQUENCE_LENGTH (1 << 16); static uint32_t sync_time = 0; static int32_t sync_cycles = 0; int catch_up_cycles = 0; int last_catch_up = 0; - uint16_t elapsed_prng_sequences; + uint16_t elapsed_prng_sequences = 1; uint16_t consecutive_resyncs = 0; int isOK = 0; + #define PRNG_SEQUENCE_LENGTH (1 << 16); + #define MAX_UNEXPECTED_RANDOM 4 // maximum number of unexpected (i.e. real) random numbers when trying to sync. Then give up. + #define MAX_SYNC_TRIES 32 + #define NUM_DEBUG_INFOS 8 // per strategy + #define MAX_STRATEGY 3 + + uint16_t unexpected_random = 0; + uint16_t sync_tries = 0; + int16_t debug_info_nr = -1; + uint16_t strategy = 0; + int32_t debug_info[MAX_STRATEGY+1][NUM_DEBUG_INFOS]; + uint32_t select_time = 0; + uint32_t halt_time = 0; + //uint8_t caller[7] = {0}; + + // init to zero. + for (uint16_t i = 0; i < MAX_STRATEGY+1; ++i) + for(uint16_t j = 0; j < NUM_DEBUG_INFOS; ++j) + debug_info[i][j] = 0; + + LED_A_ON(); + LED_B_OFF(); + LED_C_OFF(); + + if (first_try) + iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD); + + // free eventually allocated BigBuf memory. We want all for tracing. + BigBuf_free(); + clear_trace(); + set_tracing(TRUE); + if (first_try) { - mf_nr_ar3 = 0; sync_time = GetCountSspClk() & 0xfffffff8; sync_cycles = PRNG_SEQUENCE_LENGTH; //65536; //0x10000 // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces). + mf_nr_ar3 = 0; nt_attacked = 0; par[0] = 0; - } - else { + } 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(); - - - #define MAX_UNEXPECTED_RANDOM 4 // maximum number of unexpected (i.e. real) random numbers when trying to sync. Then give up. - #define MAX_SYNC_TRIES 32 - #define NUM_DEBUG_INFOS 8 // per strategy - #define MAX_STRATEGY 3 - uint16_t unexpected_random = 0; - uint16_t sync_tries = 0; - int16_t debug_info_nr = -1; - uint16_t strategy = 0; - int32_t debug_info[MAX_STRATEGY][NUM_DEBUG_INFOS]; - uint32_t select_time; - uint32_t halt_time; - - for(uint16_t i = 0; TRUE; i++) { - LED_C_ON(); + LED_C_ON(); + for(uint16_t i = 0; TRUE; ++i) { + WDT_HIT(); // Test if the action was cancelled @@ -2317,12 +2305,12 @@ void ReaderMifare(bool first_try) } if (strategy == 2) { - // test with additional hlt command + // test with additional halt command halt_time = 0; int len = mifare_sendcmd_short(NULL, false, 0x50, 0x00, receivedAnswer, receivedAnswerPar, &halt_time); - if (len && MF_DBGLEVEL >= 3) { - Dbprintf("Unexpected response of %d bytes to hlt command (additional debugging).", len); - } + + if (len && MF_DBGLEVEL >= 3) + Dbprintf("Unexpected response of %d bytes to halt command (additional debugging).\n", len); } if (strategy == 3) { @@ -2331,27 +2319,36 @@ void ReaderMifare(bool first_try) SpinDelay(200); iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD); SpinDelay(100); + sync_time = GetCountSspClk() & 0xfffffff8; + WDT_HIT(); } - if(!iso14443a_select_card(uid, NULL, &cuid, true, 0)) { - if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card"); + if (!iso14443a_select_card(uid, NULL, &cuid, true, 0)) { + if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card\n"); continue; } - select_time = GetCountSspClk(); + select_time = GetCountSspClk() & 0xfffffff8; elapsed_prng_sequences = 1; + if (debug_info_nr == -1) { + 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 + WDT_HIT(); while(GetCountSspClk() > sync_time) { - elapsed_prng_sequences++; + ++elapsed_prng_sequences; sync_time = (sync_time & 0xfffffff8) + sync_cycles; + //sync_time += sync_cycles; + //sync_time &= 0xfffffff8; } - + WDT_HIT(); // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked) - ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time); + ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time); + if (MF_DBGLEVEL == 2) Dbprintf("sync_time %d \n", sync_time); + } else { // collect some information on tag nonces for debugging: #define DEBUG_FIXED_SYNC_CYCLES PRNG_SEQUENCE_LENGTH @@ -2372,10 +2369,8 @@ void ReaderMifare(bool first_try) } // Receive the (4 Byte) "random" nonce - if (!ReaderReceive(receivedAnswer, receivedAnswerPar)) { - if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Couldn't receive tag nonce"); + if (!ReaderReceive(receivedAnswer, receivedAnswerPar)) continue; - } previous_nt = nt; nt = bytes_to_num(receivedAnswer, 4); @@ -2397,51 +2392,61 @@ void ReaderMifare(bool first_try) continue; // continue trying... } } + if (++sync_tries > MAX_SYNC_TRIES) { if (strategy > MAX_STRATEGY || MF_DBGLEVEL < 3) { isOK = -4; // Card's PRNG runs at an unexpected frequency or resets unexpectedly break; } else { // continue for a while, just to collect some debug info - debug_info[strategy][debug_info_nr] = nt_distance; - debug_info_nr++; - if (debug_info_nr == NUM_DEBUG_INFOS) { - strategy++; + ++debug_info_nr; + debug_info[strategy][debug_info_nr] = nt_distance; + if (debug_info_nr == NUM_DEBUG_INFOS-1) { + ++strategy; debug_info_nr = 0; } continue; } } + sync_cycles = (sync_cycles - nt_distance/elapsed_prng_sequences); - if (sync_cycles <= 0) { + if (sync_cycles <= 0) sync_cycles += PRNG_SEQUENCE_LENGTH; - } - if (MF_DBGLEVEL >= 3) { + + if (MF_DBGLEVEL >= 2) Dbprintf("calibrating in cycle %d. nt_distance=%d, elapsed_prng_sequences=%d, new sync_cycles: %d\n", i, nt_distance, elapsed_prng_sequences, 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; } + + // average? catch_up_cycles /= elapsed_prng_sequences; + if (catch_up_cycles == last_catch_up) { - consecutive_resyncs++; - } - else { + ++consecutive_resyncs; + } else { last_catch_up = catch_up_cycles; consecutive_resyncs = 0; } + sync_cycles += catch_up_cycles; + 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); + 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 += 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); + last_catch_up = 0; catch_up_cycles = 0; consecutive_resyncs = 0; @@ -2455,9 +2460,8 @@ void ReaderMifare(bool first_try) 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) { + 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(); @@ -2475,10 +2479,9 @@ void ReaderMifare(bool first_try) mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5); par[0] = par_low; } else { - if (nt_diff == 0 && first_try) - { + if (nt_diff == 0 && first_try) { par[0]++; - if (par[0] == 0x00) { // tried all 256 possible parities without success. Card doesn't send NACK. + if (par[0] == 0x00) { // tried all 256 possible parities without success. Card doesn't send NACK. isOK = -2; break; } @@ -2488,20 +2491,26 @@ void ReaderMifare(bool first_try) } } - mf_nr_ar[3] &= 0x1F; - + + WDT_HIT(); + if (isOK == -4) { - if (MF_DBGLEVEL >= 3) { - for (uint16_t i = 0; i <= MAX_STRATEGY; i++) { - for(uint16_t j = 0; j < NUM_DEBUG_INFOS; j++) { - Dbprintf("collected debug info[%d][%d] = %d", i, j, debug_info[i][j]); - } - } - } + for (uint16_t i = 0; i < MAX_STRATEGY+1; ++i) + for(uint16_t j = 0; j < NUM_DEBUG_INFOS; ++j) + Dbprintf("info[%d][%d] = %d", i, j, debug_info[i][j]); } - byte_t buf[28]; + // reset sync_time. + if ( isOK == 1) { + sync_time = 0; + sync_cycles = 0; + mf_nr_ar3 = 0; + nt_attacked = 0; + par[0] = 0; + } + + byte_t buf[28] = {0x00}; memcpy(buf + 0, uid, 4); num_to_bytes(nt, 4, buf + 4); memcpy(buf + 8, par_list, 8); @@ -2510,10 +2519,8 @@ void ReaderMifare(bool first_try) cmd_send(CMD_ACK,isOK,0,0,buf,28); - // Thats it... FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); LEDsoff(); - set_tracing(FALSE); } @@ -2549,10 +2556,10 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t * 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 receivedCmd[MAX_MIFARE_FRAME_SIZE] = {0x00}; + uint8_t receivedCmd_par[MAX_MIFARE_PARITY_SIZE] = {0x00}; + uint8_t response[MAX_MIFARE_FRAME_SIZE] = {0x00}; + uint8_t response_par[MAX_MIFARE_PARITY_SIZE] = {0x00}; uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; @@ -2561,7 +2568,8 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t * //uint8_t rSAK[] = {0x09, 0x3f, 0xcc }; // Mifare Mini uint8_t rSAK1[] = {0x04, 0xda, 0x17}; - uint8_t rAUTH_NT[] = {0x01, 0x01, 0x01, 0x01}; + //uint8_t rAUTH_NT[] = {0x01, 0x01, 0x01, 0x01}; + uint8_t rAUTH_NT[] = {0x55, 0x41, 0x49, 0x92}; uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00}; //Here, we collect UID1,UID2,NT,AR,NR,0,0,NT2,AR2,NR2 @@ -2712,8 +2720,7 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t * break; } case MFEMUL_AUTH1:{ - if( len != 8) - { + 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; @@ -2724,9 +2731,9 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t * //Collect AR/NR //if(ar_nr_collected < 2 && cardAUTHSC == 2){ - if(ar_nr_collected < 2){ - if(ar_nr_responses[2] != ar) - {// Avoid duplicates... probably not necessary, ar should vary. + 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*5] = 0; //ar_nr_responses[ar_nr_collected*5+1] = 0; ar_nr_responses[ar_nr_collected*5+2] = nonce; @@ -2736,9 +2743,7 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t * } // Interactive mode flag, means we need to send ACK if(flags & FLAG_INTERACTIVE && ar_nr_collected == 2) - { finished = true; - } } // --- crypto @@ -2767,9 +2772,13 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t * 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); + 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:{ @@ -2784,7 +2793,9 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t * // select 2 card if (len == 9 && - (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0)) { + (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; @@ -2811,10 +2822,9 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t * bool encrypted_data = (cardAUTHKEY != 0xFF) ; - if(encrypted_data) { - // decrypt seqence + // decrypt seqence + if(encrypted_data) mf_crypto1_decrypt(pcs, receivedCmd, len); - } if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) { authTimer = GetTickCount(); @@ -2878,9 +2888,8 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t * } // read block if (receivedCmd[0] == 0x30) { - if (MF_DBGLEVEL >= 4) { - Dbprintf("Reader reading block %d (0x%02x)",receivedCmd[1],receivedCmd[1]); - } + 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); @@ -2947,7 +2956,7 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t * break; } case MFEMUL_WRITEBL2:{ - if (len == 18){ + if (len == 18) { mf_crypto1_decrypt(pcs, receivedCmd, len); emlSetMem(receivedCmd, cardWRBL, 1); EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK)); @@ -3003,15 +3012,14 @@ void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t * FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); LEDsoff(); - if(flags & FLAG_INTERACTIVE)// Interactive mode flag, means we need to send ACK - { + // Interactive mode flag, means we need to send ACK + if(flags & FLAG_INTERACTIVE) { //May just aswell send the collected ar_nr in the response aswell uint8_t len = ar_nr_collected*5*4; cmd_send(CMD_ACK, CMD_SIMULATE_MIFARE_CARD, len, 0, &ar_nr_responses, len); } - if(flags & FLAG_NR_AR_ATTACK && MF_DBGLEVEL >= 1 ) - { + if(flags & FLAG_NR_AR_ATTACK && MF_DBGLEVEL >= 1 ) { 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 %06x%08x %08x %08x %08x %08x %08x", @@ -3060,9 +3068,8 @@ 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); @@ -3070,16 +3077,18 @@ void RAMFUNC SniffMifare(uint8_t param) { // 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]; + uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE] = {0x00}; + uint8_t receivedCmdPar[MAX_MIFARE_PARITY_SIZE] = {0x00}; + // The response (tag -> reader) that we're receiving. - uint8_t receivedResponse[MAX_MIFARE_FRAME_SIZE]; - uint8_t receivedResponsePar[MAX_MIFARE_PARITY_SIZE]; + uint8_t receivedResponse[MAX_MIFARE_FRAME_SIZE] = {0x00}; + uint8_t receivedResponsePar[MAX_MIFARE_PARITY_SIZE] = {0x00}; iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER); // 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; @@ -3130,11 +3139,12 @@ void RAMFUNC SniffMifare(uint8_t param) { 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 + + 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 { + 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; @@ -3161,10 +3171,12 @@ void RAMFUNC SniffMifare(uint8_t param) { if (sniffCounter & 0x01) { - if(!TagIsActive) { // no need to try decoding tag data if the reader is sending + // no need to try decoding tag data if the reader is sending + if(!TagIsActive) { 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. */ @@ -3176,7 +3188,8 @@ void RAMFUNC SniffMifare(uint8_t param) { ReaderIsActive = (Uart.state != STATE_UNSYNCD); } - if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending + // no need to try decoding tag data if the reader is sending + if(!ReaderIsActive) { uint8_t tagdata = (previous_data << 4) | (*data & 0x0F); if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) { LED_C_INV(); @@ -3185,6 +3198,7 @@ void RAMFUNC SniffMifare(uint8_t param) { // And ready to receive another response. DemodReset(); + // And reset the Miller decoder including its (now outdated) input buffer UartInit(receivedCmd, receivedCmdPar); } @@ -3195,9 +3209,9 @@ void RAMFUNC SniffMifare(uint8_t param) { previous_data = *data; sniffCounter++; data++; - if(data == dmaBuf + DMA_BUFFER_SIZE) { + + if(data == dmaBuf + DMA_BUFFER_SIZE) data = dmaBuf; - } } // main cycle