X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/71d90e54cdfbe625c70185b2db53e4d87d68ec14..881eacc8aad5d52b33d8585fdb5a93590545c558:/armsrc/iso14443a.c diff --git a/armsrc/iso14443a.c b/armsrc/iso14443a.c index 6b481df2..45425e07 100644 --- a/armsrc/iso14443a.c +++ b/armsrc/iso14443a.c @@ -10,22 +10,161 @@ // Routines to support ISO 14443 type A. //----------------------------------------------------------------------------- +#include "iso14443a.h" + +#include +#include #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 "crapto1/crapto1.h" #include "mifareutil.h" +#include "mifaresniff.h" +#include "BigBuf.h" +#include "protocols.h" +#include "parity.h" + +typedef struct { + enum { + DEMOD_UNSYNCD, + // DEMOD_HALF_SYNCD, + // DEMOD_MOD_FIRST_HALF, + // DEMOD_NOMOD_FIRST_HALF, + DEMOD_MANCHESTER_DATA + } state; + uint16_t twoBits; + uint16_t highCnt; + uint16_t bitCount; + uint16_t collisionPos; + uint16_t syncBit; + uint8_t parityBits; + uint8_t parityLen; + uint16_t shiftReg; + uint16_t samples; + uint16_t len; + uint32_t startTime, endTime; + uint8_t *output; + uint8_t *parity; +} tDemod; + +typedef enum { + MOD_NOMOD = 0, + MOD_SECOND_HALF, + MOD_FIRST_HALF, + MOD_BOTH_HALVES + } Modulation_t; + +typedef struct { + enum { + STATE_UNSYNCD, + STATE_START_OF_COMMUNICATION, + STATE_MILLER_X, + STATE_MILLER_Y, + STATE_MILLER_Z, + // DROP_NONE, + // DROP_FIRST_HALF, + } state; + uint16_t shiftReg; + int16_t bitCount; + uint16_t len; + uint16_t byteCntMax; + uint16_t posCnt; + uint16_t syncBit; + uint8_t parityBits; + uint8_t parityLen; + uint32_t fourBits; + uint32_t startTime, endTime; + uint8_t *output; + uint8_t *parity; +} tUart; static uint32_t iso14a_timeout; -uint8_t *trace = (uint8_t *) BigBuf; -int traceLen = 0; int rsamples = 0; -int tracing = TRUE; 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 + 8 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 later the FPGA samples the first data +// + 16 ticks until assigned to mod_sig +// + 1 tick to assign mod_sig_coil +// + a varying number of ticks in the FPGA Delay Queue (mod_sig_buf) +#define DELAY_ARM2AIR_AS_TAG (4*16 + 8 + 8*16 + 8 + 16 + 1 + DELAY_FPGA_QUEUE) + +// 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 @@ -42,520 +181,395 @@ uint8_t trigger = 0; #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(int enable) { +void iso14a_set_trigger(bool enable) { trigger = enable; } -void iso14a_clear_tracelen(void) { - traceLen = 0; + +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_tracing(int enable) { - tracing = enable; + + +static 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]; -} - -uint32_t GetParity(const uint8_t * pbtCmd, int iLen) +void GetParity(const uint8_t *pbtCmd, uint16_t iLen, uint8_t *par) { - int i; - uint32_t dwPar = 0; + 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 |= ((oddparity8(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++; + } + } - // Generate the encrypted data - for (i = 0; i < iLen; i++) { - // Save the encrypted parity bit - dwPar |= ((OddByteParity[pbtCmd[i]]) << i); - } - return dwPar; + // 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); + ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1); } -// The function LogTrace() is also used by the iClass implementation in iClass.c -int RAMFUNC LogTrace(const uint8_t * btBytes, int iLen, int iSamples, uint32_t dwParity, int bReader) +static void AppendCrc14443b(uint8_t* data, int len) { - // Return when trace is full - if (traceLen >= TRACE_SIZE) return FALSE; - - // Trace the random, i'm curious - rsamples += iSamples; - trace[traceLen++] = ((rsamples >> 0) & 0xff); - trace[traceLen++] = ((rsamples >> 8) & 0xff); - trace[traceLen++] = ((rsamples >> 16) & 0xff); - trace[traceLen++] = ((rsamples >> 24) & 0xff); - if (!bReader) { - trace[traceLen - 1] |= 0x80; - } - trace[traceLen++] = ((dwParity >> 0) & 0xff); - trace[traceLen++] = ((dwParity >> 8) & 0xff); - trace[traceLen++] = ((dwParity >> 16) & 0xff); - trace[traceLen++] = ((dwParity >> 24) & 0xff); - trace[traceLen++] = iLen; - memcpy(trace + traceLen, btBytes, iLen); - traceLen += iLen; - return TRUE; + ComputeCrc14443(CRC_14443_B,data,len,data+len,data+len+1); } -//----------------------------------------------------------------------------- -// The software UART that receives commands from the reader, and its state -// variables. + +//============================================================================= +// 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; -static RAMFUNC int MillerDecoding(int bit) -{ - //int error = 0; - int bitright; - - if(!Uart.bitBuffer) { - Uart.bitBuffer = bit ^ 0xFF0; - return FALSE; - } - else { - Uart.bitBuffer <<= 4; - Uart.bitBuffer ^= bit; - } +// Lookup-Table to decide if 4 raw bits are a modulation. +// We accept the following: +// 0001 - a 3 tick wide pause +// 0011 - a 2 tick wide pause, or a three tick wide pause shifted left +// 0111 - a 2 tick wide pause shifted left +// 1001 - a 2 tick wide pause shifted right +const bool Mod_Miller_LUT[] = { + false, true, false, true, false, false, false, true, + false, true, false, false, false, false, false, false +}; +#define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x000000F0) >> 4]) +#define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x0000000F)]) - int EOC = FALSE; +static 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.startTime = 0; + Uart.endTime = 0; +} - if(Uart.state != STATE_UNSYNCD) { - Uart.posCnt++; +static void UartInit(uint8_t *data, uint8_t *parity) +{ + Uart.output = data; + Uart.parity = parity; + Uart.fourBits = 0x00000000; // clear the buffer for 4 Bits + UartReset(); +} - 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; } +// 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) +{ - if(Uart.posCnt == 1) { - // measurement first half bitperiod - if(!bit) { - Uart.drop = DROP_FIRST_HALF; - } + Uart.fourBits = (Uart.fourBits << 8) | bit; + + if (Uart.state == STATE_UNSYNCD) { // not yet synced + + Uart.syncBit = 9999; // not set + // The start bit is one ore more Sequence Y followed by a Sequence Z (... 11111111 00x11111). We need to distinguish from + // Sequence X followed by Sequence Y followed by Sequence Z (111100x1 11111111 00x11111) + // we therefore look for a ...xx11111111111100x11111xxxxxx... pattern + // (12 '1's followed by 2 '0's, eventually followed by another '0', followed by 5 '1's) + #define ISO14443A_STARTBIT_MASK 0x07FFEF80 // mask is 00000111 11111111 11101111 10000000 + #define ISO14443A_STARTBIT_PATTERN 0x07FF8F80 // pattern is 00000111 11111111 10001111 10000000 + if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 0)) == ISO14443A_STARTBIT_PATTERN >> 0) Uart.syncBit = 7; + else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 1)) == ISO14443A_STARTBIT_PATTERN >> 1) Uart.syncBit = 6; + else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 2)) == ISO14443A_STARTBIT_PATTERN >> 2) Uart.syncBit = 5; + else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 3)) == ISO14443A_STARTBIT_PATTERN >> 3) Uart.syncBit = 4; + else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 4)) == ISO14443A_STARTBIT_PATTERN >> 4) Uart.syncBit = 3; + else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 5)) == ISO14443A_STARTBIT_PATTERN >> 5) Uart.syncBit = 2; + else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 6)) == ISO14443A_STARTBIT_PATTERN >> 6) Uart.syncBit = 1; + else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 7)) == ISO14443A_STARTBIT_PATTERN >> 7) Uart.syncBit = 0; + + if (Uart.syncBit != 9999) { // 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 { - // 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; + } else { - 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 (IsMillerModulationNibble1(Uart.fourBits >> Uart.syncBit)) { + if (IsMillerModulationNibble2(Uart.fourBits >> 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; + } } - if(Uart.drop == DROP_FIRST_HALF) { - // we see a '0' - Uart.state = STATE_MILLER_Z; + } + } + } else { + if (IsMillerModulationNibble2(Uart.fourBits >> 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; } - if(Uart.drop == DROP_SECOND_HALF) { - // We see a '1' and go to state X - Uart.shiftReg |= 0x100; - Uart.state = STATE_MILLER_X; + } + } 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 } - 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; + if (Uart.len) { + return true; // we are finished with decoding the raw data sequence + } else { + UartReset(); // Nothing received - start over } - 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; + if (Uart.state == STATE_START_OF_COMMUNICATION) { // error - must not follow directly after SOC + UartReset(); + } 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; + } } } - 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; + return false; // not finished yet, need more data } + + //============================================================================= -// ISO 14443 Type A - Manchester +// 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; -static RAMFUNC int 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; - } +// 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 +}; - 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 +#define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4]) +#define IsManchesterModulationNibble2(b) (Mod_Manchester_LUT[(b & 0x000F)]) - if(bit & 0x08) { - Demod.syncBit = 0x08; - } - if(bit & 0x04) { - if(Demod.syncBit) { - bit <<= 4; - } - Demod.syncBit = 0x04; - } +static 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; +} - if(bit & 0x02) { - if(Demod.syncBit) { - bit <<= 2; - } - Demod.syncBit = 0x02; - } +static void DemodInit(uint8_t *data, uint8_t *parity) +{ + Demod.output = data; + Demod.parity = parity; + DemodReset(); +} - if(bit & 0x01 && Demod.syncBit) { - 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) { - if(trigger) LED_A_OFF(); - 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; +// 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.samples += 4; + Demod.twoBits = (Demod.twoBits << 8) | bit; + + if (Demod.state == DEMOD_UNSYNCD) { - if(Demod.posCount==0) { - Demod.posCount = 1; - if(modulation) { - Demod.sub = SUB_FIRST_HALF; + if (Demod.highCnt < 2) { // wait for a stable unmodulated signal + if (Demod.twoBits == 0x0000) { + Demod.highCnt++; + } else { + Demod.highCnt = 0; } - else { - Demod.sub = SUB_NONE; + } 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 { - 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); + } 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(); + } } - - /*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; + return false; // not finished yet, need more data } //============================================================================= @@ -574,62 +588,56 @@ void RAMFUNC SnoopIso14443a(uint8_t param) { // bit 1 - trigger from first reader 7-bit request LEDsoff(); - // init trace buffer - traceLen = 0; - memset(trace, 0x44, TRACE_SIZE); - // 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 - int triggered = !(param & 0x03); + iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER); + + // Allocate memory from BigBuf for some buffers + // free all previous allocations first + BigBuf_free(); // 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 = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET); + 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 = (((uint8_t *)BigBuf) + RECV_RES_OFFSET); - - // 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; + 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 - int8_t *dmaBuf = ((int8_t *)BigBuf) + DMA_BUFFER_OFFSET; - int8_t *data = dmaBuf; + 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; + // Set up the demodulator for tag -> reader responses. - Demod.output = receivedResponse; - Demod.len = 0; - Demod.state = DEMOD_UNSYNCD; - + DemodInit(receivedResponse, receivedResponsePar); + // Set up the demodulator for the reader -> tag commands - memset(&Uart, 0, sizeof(Uart)); - Uart.output = receivedCmd; - Uart.byteCntMax = 32; // was 100 (greg)////////////////// - Uart.state = STATE_UNSYNCD; - - // Setup for the DMA. - FpgaSetupSsc(); + UartInit(receivedCmd, receivedCmdPar); + + // Setup and start DMA. FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); - - // And put the FPGA in the appropriate mode - // Signal field is off with the appropriate LED - LED_D_OFF(); - FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_SNIFFER); - SetAdcMuxFor(GPIO_MUXSEL_HIPKD); - - // Count of samples received so far, so that we can include timing - // information in the trace buffer. - rsamples = 0; + + // 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); + // And now we loop, receiving samples. - while(true) { + for(uint32_t rsamples = 0; true; ) { + if(BUTTON_PRESS()) { DbpString("cancelled by button"); - goto done; + break; } LED_A_ON(); @@ -640,14 +648,14 @@ void RAMFUNC SnoopIso14443a(uint8_t param) { if (readBufDataP <= dmaBufDataP){ dataLen = dmaBufDataP - readBufDataP; } else { - dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP + 1; + dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; } // test for length of buffer if(dataLen > maxDataLen) { maxDataLen = dataLen; - if(dataLen > 400) { - Dbprintf("blew circular buffer! dataLen=0x%x", dataLen); - goto done; + if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) { + Dbprintf("blew circular buffer! dataLen=%d", dataLen); + break; } } if(dataLen < 1) continue; @@ -656,6 +664,7 @@ void RAMFUNC SnoopIso14443a(uint8_t param) { 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) { @@ -665,60 +674,80 @@ void RAMFUNC SnoopIso14443a(uint8_t param) { LED_A_OFF(); - rsamples += 4; - if(MillerDecoding((data[0] & 0xF0) >> 4)) { - LED_C_ON(); - - // check - if there is a short 7bit request from reader - if ((!triggered) && (param & 0x02) && (Uart.byteCnt == 1) && (Uart.bitCnt = 9)) triggered = TRUE; - - if(triggered) { - if (!LogTrace(receivedCmd, Uart.byteCnt, 0 - Uart.samples, Uart.parityBits, TRUE)) break; + 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); } - /* 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(ManchesterDecoding(data[0] & 0x0F)) { - LED_B_ON(); + 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, 0 - Demod.samples, Demod.parityBits, FALSE)) break; + 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; + if ((!triggered) && (param & 0x01)) triggered = true; - // And ready to receive another response. - memset(&Demod, 0, sizeof(Demod)); - Demod.output = receivedResponse; - Demod.state = DEMOD_UNSYNCD; - LED_C_OFF(); + // And ready to receive another response. + DemodReset(); + // And reset the Miller decoder including itS (now outdated) input buffer + UartInit(receivedCmd, receivedCmdPar); + + LED_C_OFF(); + } + TagIsActive = (Demod.state != DEMOD_UNSYNCD); + } } + previous_data = *data; + rsamples++; data++; - if(data > dmaBuf + DMA_BUFFER_SIZE) { + if(data == dmaBuf + DMA_BUFFER_SIZE) { data = dmaBuf; } } // main cycle DbpString("COMMAND FINISHED"); -done: - AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS; - Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.byteCnt=%x", maxDataLen, Uart.state, Uart.byteCnt); - Dbprintf("Uart.byteCntMax=%x, traceLen=%x, Uart.output[0]=%08x", Uart.byteCntMax, traceLen, (int)Uart.output[0]); + 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, int len, uint32_t dwParity) +static void CodeIso14443aAsTagPar(const uint8_t *cmd, uint16_t len, uint8_t *parity) { - int i; - ToSendReset(); // Correction bit, might be removed when not needed @@ -733,13 +762,13 @@ static void CodeIso14443aAsTagPar(const uint8_t *cmd, int len, uint32_t dwParity // Send startbit ToSend[++ToSendMax] = SEC_D; + LastProxToAirDuration = 8 * ToSendMax - 4; - for(i = 0; i < len; i++) { - int j; + for(uint16_t i = 0; i < len; i++) { uint8_t b = cmd[i]; // Data bits - for(j = 0; j < 8; j++) { + for(uint16_t j = 0; j < 8; j++) { if(b & 1) { ToSend[++ToSendMax] = SEC_D; } else { @@ -749,10 +778,12 @@ static void CodeIso14443aAsTagPar(const uint8_t *cmd, int len, uint32_t dwParity } // Get the parity bit - if ((dwParity >> i) & 0x01) { + if (parity[i>>3] & (0x80>>(i&0x0007))) { ToSend[++ToSendMax] = SEC_D; + LastProxToAirDuration = 8 * ToSendMax - 4; } else { ToSend[++ToSendMax] = SEC_E; + LastProxToAirDuration = 8 * ToSendMax; } } @@ -763,18 +794,12 @@ static void CodeIso14443aAsTagPar(const uint8_t *cmd, int len, uint32_t dwParity ToSendMax++; } -static void CodeIso14443aAsTag(const uint8_t *cmd, int len){ - CodeIso14443aAsTagPar(cmd, len, GetParity(cmd, len)); -} -//----------------------------------------------------------------------------- -// This is to send a NACK kind of answer, its only 3 bits, I know it should be 4 -//----------------------------------------------------------------------------- -static void CodeStrangeAnswerAsTag() +static void Code4bitAnswerAsTag(uint8_t cmd) { int i; - ToSendReset(); + ToSendReset(); // Correction bit, might be removed when not needed ToSendStuffBit(0); @@ -789,74 +814,63 @@ static void CodeStrangeAnswerAsTag() // Send startbit ToSend[++ToSendMax] = SEC_D; - // 0 - ToSend[++ToSendMax] = SEC_E; + 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; + } - // 0 - ToSend[++ToSendMax] = SEC_E; + // Send stopbit + ToSend[++ToSendMax] = SEC_F; - // 1 - ToSend[++ToSendMax] = SEC_D; + // Convert from last byte pos to length + ToSendMax++; +} - // Send stopbit - ToSend[++ToSendMax] = SEC_F; - // Flush the buffer in FPGA!! - for(i = 0; i < 5; i++) { - ToSend[++ToSendMax] = SEC_F; - } +static uint8_t *LastReaderTraceTime = NULL; - // Convert from last byte pos to length - ToSendMax++; +static void EmLogTraceReader(void) { + // remember last reader trace start to fix timing info later + LastReaderTraceTime = BigBuf_get_addr() + BigBuf_get_traceLen(); + LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, true); } -static void Code4bitAnswerAsTag(uint8_t cmd) -{ - int i; - ToSendReset(); +static void FixLastReaderTraceTime(uint32_t tag_StartTime) { + uint32_t reader_EndTime = Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG; + uint32_t reader_StartTime = Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG; + 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_StartTime = tag_StartTime - exact_fdt - reader_modlen; + LastReaderTraceTime[0] = (reader_StartTime >> 0) & 0xff; + LastReaderTraceTime[1] = (reader_StartTime >> 8) & 0xff; + LastReaderTraceTime[2] = (reader_StartTime >> 16) & 0xff; + LastReaderTraceTime[3] = (reader_StartTime >> 24) & 0xff; +} - // 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; - } else { - ToSend[++ToSendMax] = SEC_E; - } - b >>= 1; - } - - // Send stopbit - ToSend[++ToSendMax] = SEC_F; - - // Flush the buffer in FPGA!! - for(i = 0; i < 5; i++) { - ToSend[++ToSendMax] = SEC_F; - } - - // Convert from last byte pos to length - ToSendMax++; + +static void EmLogTraceTag(uint8_t *tag_data, uint16_t tag_len, uint8_t *tag_Parity, uint32_t ProxToAirDuration) { + uint32_t tag_StartTime = LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG; + uint32_t tag_EndTime = (LastTimeProxToAirStart + ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG; + LogTrace(tag_data, tag_len, tag_StartTime, tag_EndTime, tag_Parity, false); + FixLastReaderTraceTime(tag_StartTime); } + //----------------------------------------------------------------------------- // Wait for commands from reader // Stop when button is pressed -// Or return TRUE when command is captured +// Or return true when command is captured //----------------------------------------------------------------------------- -static int GetIso14443aCommandFromReader(uint8_t *received, int *len, int maxLen) +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). @@ -865,45 +879,98 @@ static int GetIso14443aCommandFromReader(uint8_t *received, int *len, int maxLen 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; + 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_TXRDY)) { - AT91C_BASE_SSC->SSC_THR = 0x00; - } + if(BUTTON_PRESS()) return false; + if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { - uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; - if(MillerDecoding((b & 0xf0) >> 4)) { - *len = Uart.byteCnt; - return TRUE; + b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; + if(MillerDecoding(b, 0)) { + *len = Uart.len; + EmLogTraceReader(); + return true; } - if(MillerDecoding(b & 0x0f)) { - *len = Uart.byteCnt; - return TRUE; - } - } + } } } -static int EmSendCmd14443aRaw(uint8_t *resp, int respLen, int correctionNeeded); + + +static int EmSend4bitEx(uint8_t resp, bool correctionNeeded); +int EmSend4bit(uint8_t resp); +static int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par); +int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded); +int EmSendPrecompiledCmd(tag_response_info_t *response_info, bool correctionNeeded); + + +static 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 + GetParity(response_info->response, response_info->response_n, &(response_info->par)); + CodeIso14443aAsTagPar(response_info->response,response_info->response_n, &(response_info->par)); + + // 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 for the modulation +// -> need 273 bytes buffer +#define ALLOCATED_TAG_MODULATION_BUFFER_SIZE 273 + +bool prepare_allocated_tag_modulation(tag_response_info_t* response_info, uint8_t **buffer, size_t *max_buffer_size) { + + // Retrieve and store the current buffer index + response_info->modulation = *buffer; + + // Forward the prepare tag modulation function to the inner function + if (prepare_tag_modulation(response_info, *max_buffer_size)) { + // Update the free buffer offset and the remaining buffer size + *buffer += ToSendMax; + *max_buffer_size -= 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) +void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data) { - // Enable and clear the trace - tracing = TRUE; - traceLen = 0; - memset(trace, 0x44, TRACE_SIZE); - - // This function contains the tag emulation uint8_t sak; // The first response contains the ATQA (note: bytes are transmitted in reverse order). @@ -934,6 +1001,12 @@ void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd) 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; @@ -941,10 +1014,11 @@ void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd) } // The second response contains the (mandatory) first 24 bits of the UID - uint8_t response2[5]; + uint8_t response2[5] = {0x00}; // Check if the uid uses the (optional) part - uint8_t response2a[5]; + uint8_t response2a[5] = {0x00}; + if (uid_2nd) { response2[0] = 0x88; num_to_bytes(uid_1st,3,response2+1); @@ -965,70 +1039,68 @@ void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd) response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3]; // Prepare the mandatory SAK (for 4 and 7 byte UID) - uint8_t response3[3]; + 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]; + 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[] = { 0x03, 0x3B, 0x00, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS - ComputeCrc14443(CRC_14443_A, response6, 3, &response6[3], &response6[4]); - - uint8_t *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 - uint8_t *resp1 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET); - int resp1Len; - - // Anticollision cascade1 - respond with uid - uint8_t *resp2 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + 166); - 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 - uint8_t *resp2a = (((uint8_t *)BigBuf) + 1140); - int resp2aLen; - - // Acknowledge select - cascade 1 - uint8_t *resp3 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + (166*2)); - int resp3Len; - - // Acknowledge select - cascade 2 - uint8_t *resp3a = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + (166*3)); - int resp3aLen; + 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 + }; + + // We need to listen to the high-frequency, peak-detected path. + iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN); - // Response to a read request - not implemented atm - uint8_t *resp4 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + (166*4)); - int resp4Len; + BigBuf_free_keep_EM(); - // Authenticate response - nonce - uint8_t *resp5 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + (166*5)); - int resp5Len; + // allocate buffers: + uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE); + uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE); + uint8_t *free_buffer_pointer = BigBuf_malloc(ALLOCATED_TAG_MODULATION_BUFFER_SIZE); + size_t free_buffer_size = ALLOCATED_TAG_MODULATION_BUFFER_SIZE; + // clear trace + clear_trace(); + set_tracing(true); - // Authenticate response - nonce - uint8_t *resp6 = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET + (166*6)); - int resp6Len; + // 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"); + break; + } + p_response = &dynamic_response_info; + } } // Count number of wakeups received after a halt @@ -1158,225 +1225,188 @@ void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd) // 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; - } - if(cmdsRecvd > 999) { DbpString("1000 commands later..."); break; - } else { - cmdsRecvd++; } + cmdsRecvd++; - if(respLen > 0) { - EmSendCmd14443aRaw(resp, respLen, receivedCmd[0] == 0x52); + if (p_response != NULL) { + EmSendPrecompiledCmd(p_response, receivedCmd[0] == 0x52); } - if (tracing) { - LogTrace(receivedCmd,len, 0, Uart.parityBits, TRUE); - if (respdata != NULL) { - LogTrace(respdata,respsize, 0, SwapBits(GetParity(respdata,respsize),respsize), FALSE); - } - if(traceLen > TRACE_SIZE) { - DbpString("Trace full"); - break; - } + if (!tracing) { + Dbprintf("Trace Full. Simulation stopped."); + break; } - - memset(receivedCmd, 0x44, RECV_CMD_SIZE); - } + } Dbprintf("%x %x %x", happened, happened2, cmdsRecvd); LED_A_OFF(); + BigBuf_free_keep_EM(); } -//----------------------------------------------------------------------------- -// Transmit the command (to the tag) that was placed in ToSend[]. -//----------------------------------------------------------------------------- -static void TransmitFor14443a(const uint8_t *cmd, int len, int *samples, int *wait) + +// prepare a delayed transfer. This simply shifts ToSend[] by a number +// of bits specified in the delay parameter. +static void PrepareDelayedTransfer(uint16_t delay) { - int c; + 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; + } + } +} + - FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD); +//------------------------------------------------------------------------------------- +// 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); - if (wait) - if(*wait < 10) - *wait = 10; + uint32_t ThisTransferTime = 0; - for(c = 0; c < *wait;) { - if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { - AT91C_BASE_SSC->SSC_THR = 0x00; // For exact timing! - c++; - } - if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { - volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR; - (void)r; - } - WDT_HIT(); - } + 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; - c = 0; - for(;;) { - if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { - AT91C_BASE_SSC->SSC_THR = cmd[c]; - c++; - if(c >= len) { - break; - } - } - if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { - volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR; - (void)r; - } - WDT_HIT(); - } - if (samples) *samples = (c + *wait) << 3; + 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); } + //----------------------------------------------------------------------------- -// Code a 7-bit command without parity bit -// This is especially for 0x26 and 0x52 (REQA and WUPA) +// Prepare reader command (in bits, support short frames) to send to FPGA //----------------------------------------------------------------------------- -void ShortFrameFromReader(const uint8_t bt) +static void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8_t *parity) { - int j; + int i, j; int last; - uint8_t b; + uint8_t b; ToSendReset(); // Start of Communication (Seq. Z) ToSend[++ToSendMax] = SEC_Z; + LastProxToAirDuration = 8 * (ToSendMax+1) - 6; last = 0; - b = bt; - for(j = 0; j < 7; j++) { - if(b & 1) { - // Sequence X - ToSend[++ToSendMax] = SEC_X; - last = 1; - } else { - if(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; + } } - else { - // Sequence Y - ToSend[++ToSendMax] = SEC_Y; - last = 0; + b >>= 1; + } + + // Only transmit parity bit if we transmitted a complete byte + if (j == 8 && parity != NULL) { + // 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; + } } } - b >>= 1; } - // End of Communication - if(last == 0) { + // End of Communication: Logic 0 followed by Sequence Y + if (last == 0) { // Sequence Z ToSend[++ToSendMax] = SEC_Z; - } - else { + LastProxToAirDuration = 8 * (ToSendMax+1) - 6; + } else { // Sequence Y ToSend[++ToSendMax] = SEC_Y; last = 0; } - // Sequence Y ToSend[++ToSendMax] = SEC_Y; - // Just to be sure! - ToSend[++ToSendMax] = SEC_Y; - ToSend[++ToSendMax] = SEC_Y; - ToSend[++ToSendMax] = SEC_Y; - - // Convert from last character reference to length - ToSendMax++; + // Convert to length of command: + ToSendMax++; } -//----------------------------------------------------------------------------- -// Prepare reader command to send to FPGA -// -//----------------------------------------------------------------------------- -void CodeIso14443aAsReaderPar(const uint8_t * cmd, int len, uint32_t dwParity) -{ - int i, j; - int last; - uint8_t b; - - ToSendReset(); - - // Start of Communication (Seq. Z) - ToSend[++ToSendMax] = SEC_Z; - last = 0; - - // Generate send structure for the data bits - for (i = 0; i < len; i++) { - // Get the current byte to send - b = cmd[i]; - - for (j = 0; j < 8; j++) { - if (b & 1) { - // Sequence X - ToSend[++ToSendMax] = SEC_X; - last = 1; - } else { - if (last == 0) { - // Sequence Z - ToSend[++ToSendMax] = SEC_Z; - } else { - // Sequence Y - ToSend[++ToSendMax] = SEC_Y; - last = 0; - } - } - b >>= 1; - } - - // Get the parity bit - if ((dwParity >> i) & 0x01) { - // Sequence X - ToSend[++ToSendMax] = SEC_X; - last = 1; - } else { - if (last == 0) { - // Sequence Z - ToSend[++ToSendMax] = SEC_Z; - } else { - // Sequence Y - ToSend[++ToSendMax] = SEC_Y; - last = 0; - } - } - } - - // End of Communication - if (last == 0) { - // Sequence Z - ToSend[++ToSendMax] = SEC_Z; - } else { - // Sequence Y - ToSend[++ToSendMax] = SEC_Y; - last = 0; - } - // Sequence Y - ToSend[++ToSendMax] = SEC_Y; - - // Just to be sure! - ToSend[++ToSendMax] = SEC_Y; - ToSend[++ToSendMax] = SEC_Y; - ToSend[++ToSendMax] = SEC_Y; - - // Convert from last character reference to length - ToSendMax++; -} //----------------------------------------------------------------------------- // 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, int *len, int maxLen) +int EmGetCmd(uint8_t *received, uint16_t *len, uint8_t *parity) { *len = 0; @@ -1393,18 +1423,19 @@ static int EmGetCmd(uint8_t *received, int *len, int maxLen) // Set ADC to read field strength AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST; AT91C_BASE_ADC->ADC_MR = - ADC_MODE_PRESCALE(32) | - ADC_MODE_STARTUP_TIME(16) | - ADC_MODE_SAMPLE_HOLD_TIME(8); + 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. - Uart.output = received; - Uart.byteCntMax = maxLen; - Uart.state = STATE_UNSYNCD; + UartInit(received, parity); + // Clear RXRDY: + uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; + for(;;) { WDT_HIT(); @@ -1416,7 +1447,7 @@ static int EmGetCmd(uint8_t *received, int *len, int maxLen) analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF]; AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START; if (analogCnt >= 32) { - if ((33000 * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) { + if ((MAX_ADC_HF_VOLTAGE * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) { vtime = GetTickCount(); if (!timer) timer = vtime; // 50ms no field --> card to idle state @@ -1427,315 +1458,462 @@ static int EmGetCmd(uint8_t *received, int *len, int maxLen) analogAVG = 0; } } - // transmit none - if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { - AT91C_BASE_SSC->SSC_THR = 0x00; - } + // receive and test the miller decoding - if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { - volatile uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; - if(MillerDecoding((b & 0xf0) >> 4)) { - *len = Uart.byteCnt; - if (tracing) LogTrace(received, *len, GetDeltaCountUS(), Uart.parityBits, TRUE); - return 0; - } - if(MillerDecoding(b & 0x0f)) { - *len = Uart.byteCnt; - if (tracing) LogTrace(received, *len, GetDeltaCountUS(), Uart.parityBits, TRUE); + if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { + b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; + if(MillerDecoding(b, 0)) { + *len = Uart.len; + EmLogTraceReader(); return 0; } - } + } + } } -static int EmSendCmd14443aRaw(uint8_t *resp, int respLen, int correctionNeeded) -{ - int i, u = 0; - uint8_t b = 0; +static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded) +{ + uint8_t b; + uint16_t i = 0; + // Modulate Manchester FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD); - AT91C_BASE_SSC->SSC_THR = 0x00; - FpgaSetupSsc(); - - // include correction bit - i = 1; - if((Uart.parityBits & 0x01) || correctionNeeded) { + + // 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; + } + + LastTimeProxToAirStart = (GetCountSspClk() & 0xfffffff8) + (correctionNeeded?8:0); + // send cycle - for(;;) { - if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { - volatile uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; - (void)b; - } + for(; i < respLen; ) { if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { - if(i > respLen) { - b = 0xff; // was 0x00 - u++; - } else { - b = resp[i]; - i++; - } - AT91C_BASE_SSC->SSC_THR = b; - - if(u > 4) break; + 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; ) { + 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++; + } + } + return 0; } -int EmSend4bitEx(uint8_t resp, int correctionNeeded){ - Code4bitAnswerAsTag(resp); + +static int EmSend4bitEx(uint8_t resp, bool correctionNeeded){ + Code4bitAnswerAsTag(resp); int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded); - if (tracing) LogTrace(&resp, 1, GetDeltaCountUS(), GetParity(&resp, 1), FALSE); + // do the tracing for the previous reader request and this tag answer: + EmLogTraceTag(&resp, 1, NULL, LastProxToAirDuration); return res; } + int EmSend4bit(uint8_t resp){ - return EmSend4bitEx(resp, 0); + return EmSend4bitEx(resp, false); } -int EmSendCmdExPar(uint8_t *resp, int respLen, int correctionNeeded, uint32_t par){ - CodeIso14443aAsTagPar(resp, respLen, par); + +static int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par){ + CodeIso14443aAsTagPar(resp, respLen, par); int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded); - if (tracing) LogTrace(resp, respLen, GetDeltaCountUS(), par, FALSE); + // do the tracing for the previous reader request and this tag answer: + EmLogTraceTag(resp, respLen, par, LastProxToAirDuration); return res; } -int EmSendCmdEx(uint8_t *resp, int respLen, int correctionNeeded){ - return EmSendCmdExPar(resp, respLen, correctionNeeded, GetParity(resp, respLen)); + +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 EmSendCmd(uint8_t *resp, int respLen){ - return EmSendCmdExPar(resp, respLen, 0, GetParity(resp, respLen)); + +int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par){ + return EmSendCmdExPar(resp, respLen, false, par); } -int EmSendCmdPar(uint8_t *resp, int respLen, uint32_t par){ - return EmSendCmdExPar(resp, respLen, 0, par); + +int EmSendPrecompiledCmd(tag_response_info_t *response_info, bool correctionNeeded) { + int ret = EmSendCmd14443aRaw(response_info->modulation, response_info->modulation_n, correctionNeeded); + // do the tracing for the previous reader request and this tag answer: + EmLogTraceTag(response_info->response, response_info->response_n, &(response_info->par), response_info->ProxToAirDuration); + return ret; } + //----------------------------------------------------------------------------- // Wait a certain time for tag response -// If a response is captured return TRUE -// If it takes to long return FALSE +// If a response is captured return true +// If it takes too long return false //----------------------------------------------------------------------------- -static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, int maxLen, int *samples, int *elapsed) //uint8_t *buffer +static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receivedResponsePar, uint16_t offset) { - // buffer needs to be 512 bytes - int c; - + 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 - Demod.output = receivedResponse; - Demod.len = 0; - Demod.state = DEMOD_UNSYNCD; + DemodInit(receivedResponse, receivedResponsePar); - uint8_t b; - if (elapsed) *elapsed = 0; + // 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_TXRDY)) { - AT91C_BASE_SSC->SSC_THR = 0x00; // To make use of exact timing of next command from reader!! - if (elapsed) (*elapsed)++; - } if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { - if(c < iso14a_timeout) { c++; } else { return FALSE; } b = (uint8_t)AT91C_BASE_SSC->SSC_RHR; - if(ManchesterDecoding((b>>4) & 0xf)) { - *samples = ((c - 1) << 3) + 4; - return TRUE; - } - if(ManchesterDecoding(b & 0x0f)) { - *samples = c << 3; - return TRUE; + 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 ReaderTransmitShort(const uint8_t* bt) -{ - int wait = 0; - int samples = 0; - - ShortFrameFromReader(*bt); - - // Select the card - TransmitFor14443a(ToSend, ToSendMax, &samples, &wait); - // Store reader command in buffer - if (tracing) LogTrace(bt,1,0,GetParity(bt,1),TRUE); +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, int len, uint32_t par) -{ - int wait = 0; - int samples = 0; - // This is tied to other size changes - // uint8_t* frame_addr = ((uint8_t*)BigBuf) + 2024; - CodeIso14443aAsReaderPar(frame,len,par); +void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *timing) +{ + ReaderTransmitBitsPar(frame, len*8, par, timing); +} - // Select the card - TransmitFor14443a(ToSend, ToSendMax, &samples, &wait); - if(trigger) - LED_A_ON(); - // Store reader command in buffer - if (tracing) LogTrace(frame,len,0,par,TRUE); +static 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, int len) +void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *timing) { // Generate parity and redirect - ReaderTransmitPar(frame,len,GetParity(frame,len)); + uint8_t par[MAX_PARITY_SIZE]; + GetParity(frame, len, par); + ReaderTransmitBitsPar(frame, len*8, par, timing); } -int ReaderReceive(uint8_t* receivedAnswer) + +static int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset, uint8_t *parity) { - int samples = 0; - if (!GetIso14443aAnswerFromTag(receivedAnswer,160,&samples,0)) return FALSE; - if (tracing) LogTrace(receivedAnswer,Demod.len,samples,Demod.parityBits,FALSE); - if(samples == 0) return FALSE; - return Demod.len; + 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 ReaderReceivePar(uint8_t* receivedAnswer, uint32_t * parptr) + +int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity) { - int samples = 0; - if (!GetIso14443aAnswerFromTag(receivedAnswer,160,&samples,0)) return FALSE; - if (tracing) LogTrace(receivedAnswer,Demod.len,samples,Demod.parityBits,FALSE); - *parptr = Demod.parityBits; - if(samples == 0) return FALSE; - return Demod.len; + 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 anticolision procedure - * fills the uid pointer unless NULL - * fills resp_data unless NULL */ -int iso14443a_select_card(uint8_t * uid_ptr, iso14a_card_select_t * resp_data, uint32_t * cuid_ptr) { +// performs iso14443a anticollision (optional) and card select procedure +// fills the uid and cuid pointer unless NULL +// fills the card info record unless NULL +// if anticollision is false, then the UID must be provided in uid_ptr[] +// and num_cascades must be set (1: 4 Byte UID, 2: 7 Byte UID, 3: 10 Byte UID) +// requests ATS unless no_rats is true +int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, uint32_t *cuid_ptr, bool anticollision, uint8_t num_cascades, bool no_rats) { 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 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 = (((uint8_t *)BigBuf) + 3560); // was 3560 - tied to other size changes + 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; - - // clear uid - memset(uid_ptr, 0, 8); + + // init card struct + if(p_hi14a_card) { + p_hi14a_card->uidlen = 0; + memset(p_hi14a_card->uid, 0, 10); + p_hi14a_card->ats_len = 0; + } // Broadcast for a card, WUPA (0x52) will force response from all cards in the field - ReaderTransmitShort(wupa); + ReaderTransmitBitsPar(wupa, 7, NULL, NULL); + // Receive the ATQA - if(!ReaderReceive(resp)) return 0; + if(!ReaderReceive(resp, resp_par)) return 0; - if(resp_data) - memcpy(resp_data->atqa, resp, 2); + if(p_hi14a_card) { + memcpy(p_hi14a_card->atqa, resp, 2); + } + + if (anticollision) { + // clear uid + if (uid_ptr) { + memset(uid_ptr,0,10); + } + } + + // check for proprietary anticollision: + 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 // While the UID is not complete, the 3nd bit (from the right) is set in the SAK. - for(; sak & 0x04; cascade_level++) - { + 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)); - if (!ReaderReceive(resp)) return 0; - if(uid_ptr) memcpy(uid_ptr + cascade_level*4, resp, 4); - - // calculate crypto UID - if(cuid_ptr) *cuid_ptr = bytes_to_num(resp, 4); + 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); + } + 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); + } + } else { + if (cascade_level < num_cascades - 1) { + uid_resp[0] = 0x88; + memcpy(uid_resp+1, uid_ptr+cascade_level*3, 3); + } else { + memcpy(uid_resp, uid_ptr+cascade_level*3, 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 - memcpy(sel_uid+2,resp,5); - AppendCrc14443a(sel_uid,7); - ReaderTransmit(sel_uid,sizeof(sel_uid)); + 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 received during anticollision, or the provided 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)) return 0; + 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 && 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); + p_hi14a_card->uidlen += uid_resp_len; + } } - if(resp_data) { - resp_data->sak = sak; - resp_data->ats_len = 0; - } - //-- this byte not UID, it CT. http://www.nxp.com/documents/application_note/AN10927.pdf page 3 - if (uid_ptr[0] == 0x88) { - memcpy(uid_ptr, uid_ptr + 1, 7); - uid_ptr[7] = 0; + + if(p_hi14a_card) { + p_hi14a_card->sak = sak; } - if( (sak & 0x20) == 0) - return 2; // non iso14443a compliant tag + // PICC compilant with iso14443a-4 ---> (SAK & 0x20 != 0) + if( (sak & 0x20) == 0) return 2; - // Request for answer to select - if(resp_data) { // JCOP cards - if reader sent RATS then there is no MIFARE session at all!!! + if (!no_rats) { + // Request for answer to select AppendCrc14443a(rats, 2); - ReaderTransmit(rats, sizeof(rats)); - - if (!(len = ReaderReceive(resp))) return 0; - - memcpy(resp_data->ats, resp, sizeof(resp_data->ats)); - resp_data->ats_len = len; + ReaderTransmit(rats, sizeof(rats), NULL); + + if (!(len = ReaderReceive(resp, resp_par))) return 0; + + if(p_hi14a_card) { + memcpy(p_hi14a_card->ats, resp, len); + 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; + return 1; } -void iso14443a_setup() { - // Setup SSC - FpgaSetupSsc(); - // Start from off (no field generated) - // Signal field is off with the appropriate LED - LED_D_OFF(); - FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); - SpinDelay(200); +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); - // Now give it time to spin up. // Signal field is on with the appropriate LED - LED_D_ON(); - FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD); - SpinDelay(200); + 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); - iso14a_timeout = 2048; //default + // Start the timer + StartCountSspClk(); + + DemodReset(); + UartReset(); + NextTransferTime = 2*DELAY_ARM2AIR_AS_READER; + iso14a_set_timeout(1060); // 10ms default } -int iso14_apdu(uint8_t * cmd, size_t cmd_len, void * data) { - uint8_t real_cmd[cmd_len+4]; - real_cmd[0] = 0x0a; //I-Block - real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards - memcpy(real_cmd+2, cmd, cmd_len); - AppendCrc14443a(real_cmd,cmd_len+2); + +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]; + + // ISO 14443 APDU frame: PCB [CID] [NAD] APDU CRC PCB=0x02 + real_cmd[0] = 0x02; // bnr,nad,cid,chn=0; i-block(0x00) + // put block number into the PCB + real_cmd[0] |= iso14_pcb_blocknum; + memcpy(real_cmd + 1, cmd, cmd_len); + AppendCrc14443a(real_cmd, cmd_len + 1); - ReaderTransmit(real_cmd, cmd_len+4); - size_t len = ReaderReceive(data); - if(!len) - return -1; //DATA LINK ERROR + ReaderTransmit(real_cmd, cmd_len + 3, 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 >= 3 // PCB+CRC = 3 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; + } + + // crc check + if (len >=3 && !CheckCrc14443(CRC_14443_A, data_bytes, len)) { + return -1; + } + + } + + // cut frame byte + len -= 1; + // memmove(data_bytes, data_bytes + 1, len); + for (int i = 0; i < len; i++) + data_bytes[i] = data_bytes[i + 1]; return len; } @@ -1745,608 +1923,429 @@ int iso14_apdu(uint8_t * cmd, size_t cmd_len, void * data) { // Read an ISO 14443a tag. Send out commands and store answers. // //----------------------------------------------------------------------------- -void ReaderIso14443a(UsbCommand * c, UsbCommand * ack) +void ReaderIso14443a(UsbCommand *c) { iso14a_command_t param = c->arg[0]; - uint8_t * cmd = c->d.asBytes; - size_t len = c->arg[1]; - - if(param & ISO14A_REQUEST_TRIGGER) iso14a_set_trigger(1); + uint8_t *cmd = c->d.asBytes; + size_t len = c->arg[1] & 0xffff; + size_t lenbits = c->arg[1] >> 16; + uint32_t timeout = c->arg[2]; + uint32_t arg0 = 0; + byte_t buf[USB_CMD_DATA_SIZE] = {0}; + uint8_t par[MAX_PARITY_SIZE]; + bool cantSELECT = false; + + set_tracing(true); + + if(param & ISO14A_CLEAR_TRACE) { + clear_trace(); + } - if(param & ISO14A_CONNECT) { - iso14443a_setup(); - ack->arg[0] = iso14443a_select_card(ack->d.asBytes, (iso14a_card_select_t *) (ack->d.asBytes+12), NULL); - UsbSendPacket((void *)ack, sizeof(UsbCommand)); + if(param & ISO14A_REQUEST_TRIGGER) { + iso14a_set_trigger(true); } - if(param & ISO14A_SET_TIMEOUT) { - iso14a_timeout = c->arg[2]; + if(param & ISO14A_CONNECT) { + LED_A_ON(); + 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, true, 0, param & ISO14A_NO_RATS); + + // if we cant select then we cant send data + if (arg0 != 1 && arg0 != 2) { + // 1 - all is OK with ATS, 2 - without ATS + cantSELECT = true; + } + + LED_B_ON(); + cmd_send(CMD_ACK,arg0,card->uidlen,0,buf,sizeof(iso14a_card_select_t)); + LED_B_OFF(); + } } if(param & ISO14A_SET_TIMEOUT) { - iso14a_timeout = c->arg[2]; + iso14a_set_timeout(timeout); } - if(param & ISO14A_APDU) { - ack->arg[0] = iso14_apdu(cmd, len, ack->d.asBytes); - UsbSendPacket((void *)ack, sizeof(UsbCommand)); + if(param & ISO14A_APDU && !cantSELECT) { + arg0 = iso14_apdu(cmd, len, buf); + LED_B_ON(); + cmd_send(CMD_ACK, arg0, 0, 0, buf, sizeof(buf)); + LED_B_OFF(); } - if(param & ISO14A_RAW) { + if(param & ISO14A_RAW && !cantSELECT) { if(param & ISO14A_APPEND_CRC) { - AppendCrc14443a(cmd,len); + if(param & ISO14A_TOPAZMODE) { + AppendCrc14443b(cmd,len); + } else { + AppendCrc14443a(cmd,len); + } len += 2; + if (lenbits) lenbits += 16; + } + if(lenbits>0) { // want to send a specific number of bits (e.g. short commands) + if(param & ISO14A_TOPAZMODE) { + int bits_to_send = lenbits; + uint16_t i = 0; + ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 7), NULL, NULL); // first byte is always short (7bits) and no parity + bits_to_send -= 7; + while (bits_to_send > 0) { + ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 8), NULL, NULL); // following bytes are 8 bit and no parity + bits_to_send -= 8; + } + } else { + GetParity(cmd, lenbits/8, par); + ReaderTransmitBitsPar(cmd, lenbits, par, NULL); // bytes are 8 bit with odd parity + } + } else { // want to send complete bytes only + if(param & ISO14A_TOPAZMODE) { + uint16_t i = 0; + ReaderTransmitBitsPar(&cmd[i++], 7, NULL, NULL); // first byte: 7 bits, no paritiy + while (i < len) { + ReaderTransmitBitsPar(&cmd[i++], 8, NULL, NULL); // following bytes: 8 bits, no paritiy + } + } else { + ReaderTransmit(cmd,len, NULL); // 8 bits, odd parity + } } - ReaderTransmit(cmd,len); - ack->arg[0] = ReaderReceive(ack->d.asBytes); - UsbSendPacket((void *)ack, sizeof(UsbCommand)); + arg0 = ReaderReceive(buf, par); + + LED_B_ON(); + cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf)); + LED_B_OFF(); } - if(param & ISO14A_REQUEST_TRIGGER) iso14a_set_trigger(0); + 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); LEDsoff(); } -//----------------------------------------------------------------------------- -// Read an ISO 14443a tag. Send out commands and store answers. -// -//----------------------------------------------------------------------------- -void ReaderMifare(uint32_t parameter) -{ - // Mifare AUTH - uint8_t mf_auth[] = { 0x60,0x00,0xf5,0x7b }; - uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 }; - - uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + 3560); // was 3560 - tied to other size changes - traceLen = 0; - tracing = false; - - iso14443a_setup(); - - LED_A_ON(); - LED_B_OFF(); - LED_C_OFF(); - - byte_t nt_diff = 0; - LED_A_OFF(); - byte_t par = 0; - //byte_t par_mask = 0xff; - byte_t par_low = 0; - int led_on = TRUE; - uint8_t uid[8]; - uint32_t cuid; - - tracing = FALSE; - byte_t nt[4] = {0,0,0,0}; - byte_t nt_attacked[4], nt_noattack[4]; - byte_t par_list[8] = {0,0,0,0,0,0,0,0}; - byte_t ks_list[8] = {0,0,0,0,0,0,0,0}; - num_to_bytes(parameter, 4, nt_noattack); - int isOK = 0, isNULL = 0; - - while(TRUE) - { - LED_C_ON(); - FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); - SpinDelay(200); - FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD); - LED_C_OFF(); - - // Test if the action was cancelled - if(BUTTON_PRESS()) { - break; - } - if(!iso14443a_select_card(uid, NULL, &cuid)) continue; - // Transmit MIFARE_CLASSIC_AUTH - ReaderTransmit(mf_auth, sizeof(mf_auth)); +// 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. +static int32_t dist_nt(uint32_t nt1, uint32_t nt2) { - // Receive the (16 bit) "random" nonce - if (!ReaderReceive(receivedAnswer)) continue; - memcpy(nt, receivedAnswer, 4); + uint16_t i; + uint32_t nttmp1, nttmp2; - // Transmit reader nonce and reader answer - ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar),par); - - // Receive 4 bit answer - if (ReaderReceive(receivedAnswer)) - { - if ( (parameter != 0) && (memcmp(nt, nt_noattack, 4) == 0) ) continue; - - isNULL = !(nt_attacked[0] == 0) && (nt_attacked[1] == 0) && (nt_attacked[2] == 0) && (nt_attacked[3] == 0); - if ( (isNULL != 0 ) && (memcmp(nt, nt_attacked, 4) != 0) ) continue; - - if (nt_diff == 0) - { - LED_A_ON(); - memcpy(nt_attacked, nt, 4); - //par_mask = 0xf8; - par_low = par & 0x07; - } - - led_on = !led_on; - if(led_on) LED_B_ON(); else LED_B_OFF(); - par_list[nt_diff] = par; - ks_list[nt_diff] = receivedAnswer[0] ^ 0x05; + if (nt1 == nt2) return 0; - // Test if the information is complete - if (nt_diff == 0x07) { - isOK = 1; - break; - } - - nt_diff = (nt_diff + 1) & 0x07; - mf_nr_ar[3] = nt_diff << 5; - par = par_low; - } else { - if (nt_diff == 0) - { - par++; - } else { - par = (((par >> 3) + 1) << 3) | par_low; - } + 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; } - } - - LogTrace(nt, 4, 0, GetParity(nt, 4), TRUE); - LogTrace(par_list, 8, 0, GetParity(par_list, 8), TRUE); - LogTrace(ks_list, 8, 0, GetParity(ks_list, 8), TRUE); - - UsbCommand ack = {CMD_ACK, {isOK, 0, 0}}; - memcpy(ack.d.asBytes + 0, uid, 4); - memcpy(ack.d.asBytes + 4, nt, 4); - memcpy(ack.d.asBytes + 8, par_list, 8); - memcpy(ack.d.asBytes + 16, ks_list, 8); - - LED_B_ON(); - UsbSendPacket((uint8_t *)&ack, sizeof(UsbCommand)); - LED_B_OFF(); - - // Thats it... - FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); - LEDsoff(); - tracing = TRUE; - if (MF_DBGLEVEL >= 1) DbpString("COMMAND mifare FINISHED"); + return(-99999); // either nt1 or nt2 are invalid nonces } //----------------------------------------------------------------------------- -// MIFARE 1K simulate. -// +// 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 Mifare1ksim(uint8_t arg0, uint8_t arg1, uint8_t arg2, uint8_t *datain) +void ReaderMifare(bool first_try) { - int cardSTATE = MFEMUL_NOFIELD; - int _7BUID = 0; - int vHf = 0; // in mV - //int nextCycleTimeout = 0; - int res; -// uint32_t timer = 0; - uint32_t selTimer = 0; - uint32_t authTimer = 0; - uint32_t par = 0; - int len = 0; - uint8_t cardWRBL = 0; - uint8_t cardAUTHSC = 0; - uint8_t cardAUTHKEY = 0xff; // no authentication - //uint32_t cardRn = 0; - 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; - - uint8_t* receivedCmd = eml_get_bigbufptr_recbuf(); - uint8_t *response = eml_get_bigbufptr_sendbuf(); - - static uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID - - static uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; - static uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; // !!! - - static uint8_t rSAK[] = {0x08, 0xb6, 0xdd}; - static uint8_t rSAK1[] = {0x04, 0xda, 0x17}; - - static uint8_t rAUTH_NT[] = {0x01, 0x02, 0x03, 0x04}; -// static uint8_t rAUTH_NT[] = {0x1a, 0xac, 0xff, 0x4f}; - static uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00}; + // 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; - // clear trace - traceLen = 0; - tracing = true; + uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE]; + uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE]; - // Authenticate response - nonce - uint32_t nonce = bytes_to_num(rAUTH_NT, 4); - - // get UID from emul memory - emlGetMemBt(receivedCmd, 7, 1); - _7BUID = !(receivedCmd[0] == 0x00); - if (!_7BUID) { // ---------- 4BUID - rATQA[0] = 0x04; - - emlGetMemBt(rUIDBCC1, 0, 4); - rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3]; - } else { // ---------- 7BUID - rATQA[0] = 0x44; - - rUIDBCC1[0] = 0x88; - emlGetMemBt(&rUIDBCC1[1], 0, 3); - rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3]; - emlGetMemBt(rUIDBCC2, 3, 4); - rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3]; + 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); -// -------------------------------------- test area - -// -------------------------------------- END test area - // start mkseconds counter - StartCountUS(); + 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; - // We need to listen to the high-frequency, peak-detected path. - SetAdcMuxFor(GPIO_MUXSEL_HIPKD); - FpgaSetupSsc(); + 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}; + + #define PRNG_SEQUENCE_LENGTH (1 << 16); + static uint32_t sync_time; + static int32_t sync_cycles; + int catch_up_cycles = 0; + int last_catch_up = 0; + uint16_t elapsed_prng_sequences; + uint16_t consecutive_resyncs = 0; + int isOK = 0; + + if (first_try) { + mf_nr_ar3 = 0; + sync_time = GetCountSspClk() & 0xfffffff8; + sync_cycles = PRNG_SEQUENCE_LENGTH; // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the tag nonces). + nt_attacked = 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; + } - FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN); - SpinDelay(200); + LED_A_ON(); + LED_B_OFF(); + LED_C_OFF(); + - if (MF_DBGLEVEL >= 1) Dbprintf("Started. 7buid=%d", _7BUID); - // calibrate mkseconds counter - GetDeltaCountUS(); - while (true) { + #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(); WDT_HIT(); + // Test if the action was cancelled if(BUTTON_PRESS()) { + isOK = -1; break; } - - // find reader field - // Vref = 3300mV, and an 10:1 voltage divider on the input - // can measure voltages up to 33000 mV - if (cardSTATE == MFEMUL_NOFIELD) { - vHf = (33000 * AvgAdc(ADC_CHAN_HF)) >> 10; - if (vHf > MF_MINFIELDV) { - cardSTATE_TO_IDLE(); - LED_A_ON(); + + if (strategy == 2) { + // test with additional hlt 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 (cardSTATE != MFEMUL_NOFIELD) { - res = EmGetCmd(receivedCmd, &len, RECV_CMD_SIZE); // (+ nextCycleTimeout) - if (res == 2) { - cardSTATE = MFEMUL_NOFIELD; - LEDsoff(); - continue; - } - if(res) break; + if (strategy == 3) { + // test with FPGA power off/on + FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); + SpinDelay(200); + iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD); + SpinDelay(100); } - //nextCycleTimeout = 0; - -// if (len) Dbprintf("len:%d cmd: %02x %02x %02x %02x", len, receivedCmd[0], receivedCmd[1], receivedCmd[2], receivedCmd[3]); - - if (len != 4 && cardSTATE != MFEMUL_NOFIELD) { // len != 4 <---- speed up the code 4 authentication - // 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; - } + if(!iso14443a_select_card(uid, NULL, &cuid, true, 0, true)) { + if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card"); + continue; } - - switch (cardSTATE) { - case MFEMUL_NOFIELD:{ - break; - } - case MFEMUL_HALTED:{ - break; - } - case MFEMUL_IDLE:{ - break; + select_time = GetCountSspClk(); + + 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 + while(GetCountSspClk() > sync_time) { + elapsed_prng_sequences++; + sync_time = (sync_time & 0xfffffff8) + sync_cycles; } - case MFEMUL_SELECT1:{ - // select all - if (len == 2 && (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x20)) { - EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1)); - break; - } - // select card - if (len == 9 && - (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) { - if (!_7BUID) - EmSendCmd(rSAK, sizeof(rSAK)); - else - EmSendCmd(rSAK1, sizeof(rSAK1)); - - 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; - } - } - - break; + // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked) + ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time); + } else { + // collect some information on tag nonces for debugging: + #define DEBUG_FIXED_SYNC_CYCLES PRNG_SEQUENCE_LENGTH + if (strategy == 0) { + // nonce distances at fixed time after card select: + sync_time = select_time + DEBUG_FIXED_SYNC_CYCLES; + } else if (strategy == 1) { + // nonce distances at fixed time between authentications: + sync_time = sync_time + DEBUG_FIXED_SYNC_CYCLES; + } else if (strategy == 2) { + // nonce distances at fixed time after halt: + sync_time = halt_time + DEBUG_FIXED_SYNC_CYCLES; + } else { + // nonce_distances at fixed time after power on + sync_time = DEBUG_FIXED_SYNC_CYCLES; } - case MFEMUL_SELECT2:{ - if (!len) break; - - if (len == 2 && (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x20)) { - EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2)); - break; - } + ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time); + } - // select 2 card - if (len == 9 && - (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0)) { - EmSendCmd(rSAK, sizeof(rSAK)); + // Receive the (4 Byte) "random" nonce + if (!ReaderReceive(receivedAnswer, receivedAnswerPar)) { + if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Couldn't receive tag nonce"); + continue; + } - 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) break; - cardSTATE = MFEMUL_WORK; - goto lbWORK; - } - case MFEMUL_AUTH1:{ - if (len == 8) { - // --- crypto - //rn_enc = bytes_to_num(receivedCmd, 4); - //cardRn = rn_enc ^ crypto1_word(pcs, rn_enc , 1); - cardRr = bytes_to_num(&receivedCmd[4], 4) ^ crypto1_word(pcs, 0, 0); - // test if auth OK - if (cardRr != prng_successor(nonce, 64)){ - if (MF_DBGLEVEL >= 4) Dbprintf("AUTH FAILED. cardRr=%08x, succ=%08x", cardRr, prng_successor(nonce, 64)); - cardSTATE_TO_IDLE(); - 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)); - cardSTATE = MFEMUL_AUTH2; - } else { - cardSTATE_TO_IDLE(); - } - if (cardSTATE != MFEMUL_AUTH2) break; - } - case MFEMUL_AUTH2:{ - LED_C_ON(); - cardSTATE = MFEMUL_WORK; - if (MF_DBGLEVEL >= 4) Dbprintf("AUTH COMPLETED. sec=%d, key=%d time=%d", cardAUTHSC, cardAUTHKEY, GetTickCount() - authTimer); - break; - } - case MFEMUL_WORK:{ -lbWORK: if (len == 0) break; - - if (cardAUTHKEY == 0xff) { - // first authentication - if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) { - authTimer = GetTickCount(); - - cardAUTHSC = receivedCmd[1] / 4; // received block num - cardAUTHKEY = receivedCmd[0] - 0x60; - - // --- crypto - crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY)); - ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0); - num_to_bytes(nonce, 4, rAUTH_AT); - EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT)); - // --- crypto - -// last working revision -// EmSendCmd14443aRaw(resp1, resp1Len, 0); -// LogTrace(NULL, 0, GetDeltaCountUS(), 0, true); - - cardSTATE = MFEMUL_AUTH1; - //nextCycleTimeout = 10; - break; - } - } else { - // decrypt seqence - mf_crypto1_decrypt(pcs, receivedCmd, len); - - // nested authentication - if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) { - authTimer = GetTickCount(); - - cardAUTHSC = receivedCmd[1] / 4; // received block num - cardAUTHKEY = receivedCmd[0] - 0x60; - - // --- crypto - crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY)); - ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0); - num_to_bytes(ans, 4, rAUTH_AT); - EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT)); - // --- crypto - - cardSTATE = MFEMUL_AUTH1; - //nextCycleTimeout = 10; - 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; - } - - // read block - if (len == 4 && receivedCmd[0] == 0x30) { - if (receivedCmd[1] >= 16 * 4 || receivedCmd[1] / 4 != cardAUTHSC) { - EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); - break; - } - emlGetMem(response, receivedCmd[1], 1); - AppendCrc14443a(response, 16); - mf_crypto1_encrypt(pcs, response, 18, &par); - EmSendCmdPar(response, 18, par); - break; - } - - // write block - if (len == 4 && receivedCmd[0] == 0xA0) { - if (receivedCmd[1] >= 16 * 4 || receivedCmd[1] / 4 != cardAUTHSC) { - EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); - break; - } - EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK)); - //nextCycleTimeout = 50; - cardSTATE = MFEMUL_WRITEBL2; - cardWRBL = receivedCmd[1]; - break; - } - - // works with cardINTREG - - // increment, decrement, restore - if (len == 4 && (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2)) { - if (receivedCmd[1] >= 16 * 4 || - receivedCmd[1] / 4 != cardAUTHSC || - emlCheckValBl(receivedCmd[1])) { - EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); + 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 + unexpected_random++; + if (unexpected_random > MAX_UNEXPECTED_RANDOM) { + isOK = -3; // Card has an unpredictable PRNG. Give up break; + } else { + continue; // continue trying... } - 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 (len == 4 && receivedCmd[0] == 0xB0) { - if (receivedCmd[1] >= 16 * 4 || receivedCmd[1] / 4 != cardAUTHSC) { - EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); + 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 = 0; + } + continue; } - - 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 (len == 4 && (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); - break; + sync_cycles = (sync_cycles - nt_distance/elapsed_prng_sequences); + if (sync_cycles <= 0) { + sync_cycles += PRNG_SEQUENCE_LENGTH; } - - // command not allowed - if (len == 4) { - EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA)); - break; + if (MF_DBGLEVEL >= 3) { + 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; + } + } - // case break - break; + 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; } - 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; - break; - } else { - cardSTATE_TO_IDLE(); - break; - } - break; + catch_up_cycles /= elapsed_prng_sequences; + if (catch_up_cycles == last_catch_up) { + consecutive_resyncs++; } - - 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; - } - cardINTREG = cardINTREG + ans; - cardSTATE = MFEMUL_WORK; + 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); + last_catch_up = 0; + catch_up_cycles = 0; + consecutive_resyncs = 0; + } + 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; } - 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(); + + 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]++; + if (par[0] == 0x00) { // tried all 256 possible parities without success. Card doesn't send NACK. + isOK = -2; break; } - cardINTREG = cardINTREG - ans; - cardSTATE = MFEMUL_WORK; - break; + } else { + par[0] = ((par[0] & 0x1F) + 1) | par_low; } - 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; + } + } + + + mf_nr_ar[3] &= 0x1F; + + 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]); } - cardSTATE = MFEMUL_WORK; - break; } } } + + 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(); - // add trace trailer - memset(rAUTH_NT, 0x44, 4); - LogTrace(rAUTH_NT, 4, 0, 0, TRUE); - - if (MF_DBGLEVEL >= 1) Dbprintf("Emulator stopped. Tracing: %d trace length: %d ", tracing, traceLen); + set_tracing(false); } + //----------------------------------------------------------------------------- // MIFARE sniffer. // @@ -2359,86 +2358,88 @@ void RAMFUNC SniffMifare(uint8_t param) { // C(red) A(yellow) B(green) LEDsoff(); // init trace buffer - traceLen = 0; - memset(trace, 0x44, TRACE_SIZE); + 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 = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET); + 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 = (((uint8_t *)BigBuf) + RECV_RES_OFFSET); + 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; - - // The DMA buffer, used to stream samples from the FPGA - int8_t *dmaBuf = ((int8_t *)BigBuf) + DMA_BUFFER_OFFSET; - int8_t *data = dmaBuf; + 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; + uint8_t previous_data = 0; int maxDataLen = 0; int dataLen = 0; + bool ReaderIsActive = false; + bool TagIsActive = false; // Set up the demodulator for tag -> reader responses. - Demod.output = receivedResponse; - Demod.len = 0; - Demod.state = DEMOD_UNSYNCD; + DemodInit(receivedResponse, receivedResponsePar); // Set up the demodulator for the reader -> tag commands - memset(&Uart, 0, sizeof(Uart)); - Uart.output = receivedCmd; - Uart.byteCntMax = 32; // was 100 (greg)////////////////// - Uart.state = STATE_UNSYNCD; + UartInit(receivedCmd, receivedCmdPar); // Setup for the DMA. - FpgaSetupSsc(); - FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); + FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer. - // And put the FPGA in the appropriate mode - // Signal field is off with the appropriate LED LED_D_OFF(); - FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_SNIFFER); - SetAdcMuxFor(GPIO_MUXSEL_HIPKD); // init sniffer MfSniffInit(); - int sniffCounter = 0; // And now we loop, receiving samples. - while(true) { + for(uint32_t sniffCounter = 0; true; ) { + if(BUTTON_PRESS()) { DbpString("cancelled by button"); - goto done; + break; } LED_A_ON(); WDT_HIT(); - if (++sniffCounter > 65) { - if (MfSniffSend(2000)) { - FpgaEnableSscDma(); + 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. } - sniffCounter = 0; } - - 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 + 1; + + 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) { - maxDataLen = dataLen; - if(dataLen > 400) { + 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); - goto done; + break; } } if(dataLen < 1) continue; - // primary buffer was stopped( <-- we lost data! + // 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; @@ -2452,44 +2453,53 @@ void RAMFUNC SniffMifare(uint8_t param) { LED_A_OFF(); - if(MillerDecoding((data[0] & 0xF0) >> 4)) { - LED_C_INV(); - // check - if there is a short 7bit request from reader - if (MfSniffLogic(receivedCmd, Uart.byteCnt, Uart.parityBits, Uart.bitCnt, TRUE)) break; - - /* And ready to receive another command. */ - Uart.state = STATE_UNSYNCD; - - /* And also reset the demod code */ - Demod.state = DEMOD_UNSYNCD; - } + if (sniffCounter & 0x01) { - if(ManchesterDecoding(data[0] & 0x0F)) { - LED_C_INV(); + 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; - if (MfSniffLogic(receivedResponse, Demod.len, Demod.parityBits, Demod.bitCount, FALSE)) break; + /* And ready to receive another command. */ + UartInit(receivedCmd, receivedCmdPar); + + /* 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(); - // And ready to receive another response. - memset(&Demod, 0, sizeof(Demod)); - Demod.output = receivedResponse; - Demod.state = DEMOD_UNSYNCD; + if (MfSniffLogic(receivedResponse, Demod.len, Demod.parity, Demod.bitCount, false)) break; - /* And also reset the uart code */ - Uart.state = STATE_UNSYNCD; + // And ready to receive another response. + DemodReset(); + // And reset the Miller decoder including its (now outdated) input buffer + UartInit(receivedCmd, receivedCmdPar); + } + TagIsActive = (Demod.state != DEMOD_UNSYNCD); + } } + previous_data = *data; + sniffCounter++; data++; - if(data > dmaBuf + DMA_BUFFER_SIZE) { + if(data == dmaBuf + DMA_BUFFER_SIZE) { data = dmaBuf; } + } // main cycle DbpString("COMMAND FINISHED"); -done: FpgaDisableSscDma(); MfSniffEnd(); - Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.byteCnt=%x Uart.byteCntMax=%x", maxDataLen, Uart.state, Uart.byteCnt, Uart.byteCntMax); + Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len); LEDsoff(); -} \ No newline at end of file +}