X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/3ad48540d4d77f50cc62d16acb78f17019ef431d..25d52dd261bc454dafeedc31c9b3d62b8832b23a:/armsrc/legicrf.c diff --git a/armsrc/legicrf.c b/armsrc/legicrf.c index 3fbdf5cb..b1378b81 100644 --- a/armsrc/legicrf.c +++ b/armsrc/legicrf.c @@ -7,15 +7,7 @@ //----------------------------------------------------------------------------- // LEGIC RF simulation code //----------------------------------------------------------------------------- - -#include "proxmark3.h" -#include "apps.h" -#include "util.h" -#include "string.h" - #include "legicrf.h" -#include "legic_prng.h" -#include "crc.h" static struct legic_frame { int bits; @@ -40,21 +32,21 @@ static int legic_reqresp_drift; AT91PS_TC timer; AT91PS_TC prng_timer; -static void setup_timer(void) -{ - /* Set up Timer 1 to use for measuring time between pulses. Since we're bit-banging - * this it won't be terribly accurate but should be good enough. - */ +/* +static void setup_timer(void) { + // Set up Timer 1 to use for measuring time between pulses. Since we're bit-banging + // this it won't be terribly accurate but should be good enough. + // AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC1); timer = AT91C_BASE_TC1; timer->TC_CCR = AT91C_TC_CLKDIS; timer->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK; timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; - /* - * Set up Timer 2 to use for measuring time between frames in - * tag simulation mode. Runs 4x faster as Timer 1 - */ + // + // Set up Timer 2 to use for measuring time between frames in + // tag simulation mode. Runs 4x faster as Timer 1 + // AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC2); prng_timer = AT91C_BASE_TC2; prng_timer->TC_CCR = AT91C_TC_CLKDIS; @@ -62,145 +54,206 @@ static void setup_timer(void) prng_timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; } -/* At TIMER_CLOCK3 (MCK/32) */ -#define RWD_TIME_1 150 /* RWD_TIME_PAUSE off, 80us on = 100us */ -#define RWD_TIME_0 90 /* RWD_TIME_PAUSE off, 40us on = 60us */ -#define RWD_TIME_PAUSE 30 /* 20us */ -#define RWD_TIME_FUZZ 20 /* rather generous 13us, since the peak detector + hysteresis fuzz quite a bit */ -#define TAG_TIME_BIT 150 /* 100us for every bit */ -#define TAG_TIME_WAIT 490 /* time from RWD frame end to tag frame start, experimentally determined */ + AT91C_BASE_PMC->PMC_PCER |= (0x1 << 12) | (0x1 << 13) | (0x1 << 14); + AT91C_BASE_TCB->TCB_BMR = AT91C_TCB_TC0XC0S_NONE | AT91C_TCB_TC1XC1S_TIOA0 | AT91C_TCB_TC2XC2S_NONE; + + // fast clock + AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable + AT91C_BASE_TC0->TC_CMR = AT91C_TC_CLKS_TIMER_DIV3_CLOCK | // MCK(48MHz)/32 -- tick=1.5mks + AT91C_TC_WAVE | AT91C_TC_WAVESEL_UP_AUTO | AT91C_TC_ACPA_CLEAR | + AT91C_TC_ACPC_SET | AT91C_TC_ASWTRG_SET; + AT91C_BASE_TC0->TC_RA = 1; + AT91C_BASE_TC0->TC_RC = 0xBFFF + 1; // 0xC000 + +*/ + +// At TIMER_CLOCK3 (MCK/32) +//#define RWD_TIME_1 150 /* RWD_TIME_PAUSE off, 80us on = 100us */ +//#define RWD_TIME_0 90 /* RWD_TIME_PAUSE off, 40us on = 60us */ +//#define RWD_TIME_PAUSE 30 /* 20us */ + +// testing calculating in (us) microseconds. +#define RWD_TIME_1 120 // READER_TIME_PAUSE 20us off, 80us on = 100us 80 * 1.5 == 120ticks +#define RWD_TIME_0 60 // READER_TIME_PAUSE 20us off, 40us on = 60us 40 * 1.5 == 60ticks +#define RWD_TIME_PAUSE 30 // 20us == 20 * 1.5 == 30ticks */ +#define TAG_BIT_PERIOD 150 // 100us == 100 * 1.5 == 150ticks +#define TAG_FRAME_WAIT 495 // 330us from READER frame end to TAG frame start. 330 * 1.5 == 495 + +#define RWD_TIME_FUZZ 20 // rather generous 13us, since the peak detector + hysteresis fuzz quite a bit #define SIM_DIVISOR 586 /* prng_time/SIM_DIVISOR count prng needs to be forwared */ #define SIM_SHIFT 900 /* prng_time+SIM_SHIFT shift of delayed start */ -#define SESSION_IV 0x55 #define OFFSET_LOG 1024 #define FUZZ_EQUAL(value, target, fuzz) ((value) > ((target)-(fuzz)) && (value) < ((target)+(fuzz))) +#ifndef SHORT_COIL +# define SHORT_COIL LOW(GPIO_SSC_DOUT); +#endif +#ifndef OPEN_COIL +# define OPEN_COIL HIGH(GPIO_SSC_DOUT); +#endif + +uint32_t sendFrameStop = 0; + +// Pause pulse, off in 20us / 30ticks, +// ONE / ZERO bit pulse, +// one == 80us / 120ticks +// zero == 40us / 60ticks +#ifndef COIL_PULSE +# define COIL_PULSE(x) \ + do { \ + SHORT_COIL; \ + WaitTicks( (RWD_TIME_PAUSE) ); \ + OPEN_COIL; \ + WaitTicks((x)); \ + } while (0) +#endif + +// ToDo: define a meaningful maximum size for auth_table. The bigger this is, the lower will be the available memory for traces. +// Historically it used to be FREE_BUFFER_SIZE, which was 2744. +#define LEGIC_CARD_MEMSIZE 1024 +static uint8_t* cardmem; + +static void frame_append_bit(struct legic_frame * const f, int bit) { + // Overflow, won't happen + if (f->bits >= 31) return; + + f->data |= (bit << f->bits); + f->bits++; +} + +static void frame_clean(struct legic_frame * const f) { + f->data = 0; + f->bits = 0; +} + +// Prng works when waiting in 99.1us cycles. +// and while sending/receiving in bit frames (100, 60) +/*static void CalibratePrng( uint32_t time){ + // Calculate Cycles based on timer 100us + uint32_t i = (time - sendFrameStop) / 100 ; + + // substract cycles of finished frames + int k = i - legic_prng_count()+1; + + // substract current frame length, rewind to beginning + if ( k > 0 ) + legic_prng_forward(k); +} +*/ + /* Generate Keystream */ -static uint32_t get_key_stream(int skip, int count) -{ - uint32_t key=0; int i; - - /* Use int to enlarge timer tc to 32bit */ - legic_prng_bc += prng_timer->TC_CV; - prng_timer->TC_CCR = AT91C_TC_SWTRG; - - /* If skip == -1, forward prng time based */ - if(skip == -1) { - i = (legic_prng_bc+SIM_SHIFT)/SIM_DIVISOR; /* Calculate Cycles based on timer */ - i -= legic_prng_count(); /* substract cycles of finished frames */ - i -= count; /* substract current frame length, rewidn to bedinning */ - legic_prng_forward(i); - } else { - legic_prng_forward(skip); - } - - /* Write Time Data into LOG */ - if(count == 6) { i = -1; } else { i = legic_read_count; } - ((uint8_t*)BigBuf)[OFFSET_LOG+128+i] = legic_prng_count(); - ((uint8_t*)BigBuf)[OFFSET_LOG+256+i*4] = (legic_prng_bc >> 0) & 0xff; - ((uint8_t*)BigBuf)[OFFSET_LOG+256+i*4+1] = (legic_prng_bc >> 8) & 0xff; - ((uint8_t*)BigBuf)[OFFSET_LOG+256+i*4+2] = (legic_prng_bc >>16) & 0xff; - ((uint8_t*)BigBuf)[OFFSET_LOG+256+i*4+3] = (legic_prng_bc >>24) & 0xff; - ((uint8_t*)BigBuf)[OFFSET_LOG+384+i] = count; - - /* Generate KeyStream */ - for(i=0; iTC_CV; + + // reset the prng timer. + ResetTimer(prng_timer); + + /* If skip == -1, forward prng time based */ + if(skip == -1) { + i = (legic_prng_bc + SIM_SHIFT)/SIM_DIVISOR; /* Calculate Cycles based on timer */ + i -= legic_prng_count(); /* substract cycles of finished frames */ + i -= count; /* substract current frame length, rewind to beginning */ + legic_prng_forward(i); + } else { + legic_prng_forward(skip); + } + + i = (count == 6) ? -1 : legic_read_count; + + /* Write Time Data into LOG */ + // uint8_t *BigBuf = BigBuf_get_addr(); + // BigBuf[OFFSET_LOG+128+i] = legic_prng_count(); + // BigBuf[OFFSET_LOG+256+i*4] = (legic_prng_bc >> 0) & 0xff; + // BigBuf[OFFSET_LOG+256+i*4+1] = (legic_prng_bc >> 8) & 0xff; + // BigBuf[OFFSET_LOG+256+i*4+2] = (legic_prng_bc >>16) & 0xff; + // BigBuf[OFFSET_LOG+256+i*4+3] = (legic_prng_bc >>24) & 0xff; + // BigBuf[OFFSET_LOG+384+i] = count; + + /* Generate KeyStream */ + for(i=0; iPIO_CODR = GPIO_SSC_DOUT; - AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT; - AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT; - - /* Use time to crypt frame */ - if(crypt) { - legic_prng_forward(2); /* TAG_TIME_WAIT -> shift by 2 */ - int i; int key = 0; - for(i=0; iPIO_OER = GPIO_SSC_DOUT; + AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT; - /* Wait for the frame start */ - while(timer->TC_CV < (TAG_TIME_WAIT - 30)) ; - - int i; - for(i=0; iTC_CV + TAG_TIME_BIT; - int bit = response & 1; - response = response >> 1; - if(bit) { - AT91C_BASE_PIOA->PIO_SODR = GPIO_SSC_DOUT; - } else { - AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT; - } - while(timer->TC_CV < nextbit) ; + /* Use time to crypt frame */ + if(crypt) { + legic_prng_forward(2); /* TAG_FRAME_WAIT -> shift by 2 */ + response ^= legic_prng_get_bits(bits); + } + + /* Wait for the frame start */ + WaitUS( TAG_FRAME_WAIT ); + + uint8_t bit = 0; + for(int i = 0; i < bits; i++) { + + bit = response & 1; + response >>= 1; + + if (bit) + HIGH(GPIO_SSC_DOUT); + else + LOW(GPIO_SSC_DOUT); + + WaitUS(100); } - AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT; + LOW(GPIO_SSC_DOUT); } /* Send a frame in reader mode, the FPGA must have been set up by * LegicRfReader */ -static void frame_send_rwd(uint32_t data, int bits) -{ - /* Start clock */ - timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; - while(timer->TC_CV > 1) ; /* Wait till the clock has reset */ +void frame_sendAsReader(uint32_t data, uint8_t bits){ - int i; - for(i=0; iTC_CV; - int pause_end = starttime + RWD_TIME_PAUSE, bit_end; - int bit = data & 1; - data = data >> 1; - - if(bit ^ legic_prng_get_bit()) { - bit_end = starttime + RWD_TIME_1; + uint32_t starttime = GET_TICKS, send = 0; + uint16_t mask = 1; + uint8_t prng1 = legic_prng_count() ; + + // xor lsfr onto data. + send = data ^ legic_prng_get_bits(bits); + + for (; mask < BITMASK(bits); mask <<= 1) { + if (send & mask) { + COIL_PULSE(RWD_TIME_1); } else { - bit_end = starttime + RWD_TIME_0; + COIL_PULSE(RWD_TIME_0); } - - /* RWD_TIME_PAUSE time off, then some time on, so that the complete bit time is - * RWD_TIME_x, where x is the bit to be transmitted */ - AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT; - while(timer->TC_CV < pause_end) ; - AT91C_BASE_PIOA->PIO_SODR = GPIO_SSC_DOUT; - legic_prng_forward(1); /* bit duration is longest. use this time to forward the lfsr */ - - while(timer->TC_CV < bit_end) ; - } - - { - /* One final pause to mark the end of the frame */ - int pause_end = timer->TC_CV + RWD_TIME_PAUSE; - AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT; - while(timer->TC_CV < pause_end) ; - AT91C_BASE_PIOA->PIO_SODR = GPIO_SSC_DOUT; } - /* Reset the timer, to measure time until the start of the tag frame */ - timer->TC_CCR = AT91C_TC_SWTRG; - while(timer->TC_CV > 1) ; /* Wait till the clock has reset */ + // Final pause to mark the end of the frame + COIL_PULSE(0); + + sendFrameStop = GET_TICKS; + uint8_t cmdbytes[] = { + BYTEx(data, 0), + BYTEx(data, 1), + bits, + prng1, + legic_prng_count() + }; + LogTrace(cmdbytes, sizeof(cmdbytes), starttime, sendFrameStop, NULL, TRUE); } /* Receive a frame from the card in reader emulation mode, the FPGA and - * timer must have been set up by LegicRfReader and frame_send_rwd. + * timer must have been set up by LegicRfReader and frame_sendAsReader. * * The LEGIC RF protocol from card to reader does not include explicit * frame start/stop information or length information. The reader must @@ -213,129 +266,164 @@ static void frame_send_rwd(uint32_t data, int bits) * for edges. Count the edges in each bit interval. If they are approximately * 0 this was a 0-bit, if they are approximately equal to the number of edges * expected for a 212kHz subcarrier, this was a 1-bit. For timing we use the - * timer that's still running from frame_send_rwd in order to get a synchronization + * timer that's still running from frame_sendAsReader in order to get a synchronization * with the frame that we just sent. * * FIXME: Because we're relying on the hysteresis to just do the right thing * the range is severely reduced (and you'll probably also need a good antenna). * So this should be fixed some time in the future for a proper receiver. */ -static void frame_receive_rwd(struct legic_frame * const f, int bits, int crypt) -{ - uint32_t the_bit = 1; /* Use a bitmask to save on shifts */ - uint32_t data=0; - int i, old_level=0, edges=0; - int next_bit_at = TAG_TIME_WAIT; - - if(bits > 32) { - bits = 32; - } +static void frame_receiveAsReader(struct legic_frame * const f, uint8_t bits) { + frame_clean(f); + if ( bits > 32 ) return; + + uint8_t i = bits, edges = 0; + uint16_t lsfr = 0; + uint32_t the_bit = 1, next_bit_at = 0, data; + + int old_level = 0, level = 0; + AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_DIN; AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DIN; - - /* we have some time now, precompute the cipher - * since we cannot compute it on the fly while reading */ + + // calibrate the prng. legic_prng_forward(2); + + // precompute the cipher + uint8_t prng_before = legic_prng_count() ; - if(crypt) - { - for(i=0; iTC_CV < next_bit_at) ; + data = lsfr; + + //FIXED time between sending frame and now listening frame. 330us + //WaitTicks( TAG_FRAME_WAIT - (GET_TICKS - sendFrameStop ) ); + WaitTicks( 495 ); - next_bit_at += TAG_TIME_BIT; + uint32_t starttime = GET_TICKS; + next_bit_at = GET_TICKS + TAG_BIT_PERIOD; - for(i=0; iTC_CV < next_bit_at) { - int level = (AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN); - if(level != old_level) - edges++; + uint8_t adjust = 0; + while ( GET_TICKS < next_bit_at) { + + level = (AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN); + + if (level != old_level) + ++edges; + old_level = level; - } - next_bit_at += TAG_TIME_BIT; + + if(edges > 20 && adjust == 0) { + next_bit_at -= 15; + adjust = 1; + } + } + + next_bit_at += TAG_BIT_PERIOD; - if(edges > 20 && edges < 60) { /* expected are 42 edges */ + // We expect 42 edges == ONE + if(edges > 20 && edges < 64) data ^= the_bit; - } - the_bit <<= 1; + + the_bit <<= 1; } + // output f->data = data; f->bits = bits; - - /* Reset the timer, to synchronize the next frame */ - timer->TC_CCR = AT91C_TC_SWTRG; - while(timer->TC_CV > 1) ; /* Wait till the clock has reset */ -} - -static void frame_append_bit(struct legic_frame * const f, int bit) -{ - if(f->bits >= 31) { - return; /* Overflow, won't happen */ - } - f->data |= (bit<bits); - f->bits++; -} - -static void frame_clean(struct legic_frame * const f) -{ - f->data = 0; - f->bits = 0; + + // log + sendFrameStop = GET_TICKS; + + uint8_t cmdbytes[] = { + BYTEx(data,0), + BYTEx(data,1), + bits, + BYTEx(lsfr,0), + BYTEx(lsfr,1), + BYTEx(data, 0) ^ BYTEx(lsfr,0), + BYTEx(data, 1) ^ BYTEx(lsfr,1), + prng_before, + legic_prng_count() + }; + LogTrace(cmdbytes, sizeof(cmdbytes), starttime, sendFrameStop, NULL, FALSE); } -static uint32_t perform_setup_phase_rwd(int iv) -{ - - /* Switch on carrier and let the tag charge for 1ms */ - AT91C_BASE_PIOA->PIO_SODR = GPIO_SSC_DOUT; - SpinDelay(1); +// Setup pm3 as a Legic Reader +static uint32_t setup_phase_reader(uint8_t iv) { + + // Switch on carrier and let the tag charge for 1ms + HIGH(GPIO_SSC_DOUT); + WaitUS(1000); + + ResetTicks(); + + // no keystream yet + legic_prng_init(0); + + // send IV handshake + frame_sendAsReader(iv, 7); - legic_prng_init(0); /* no keystream yet */ - frame_send_rwd(iv, 7); + // Now both tag and reader has same IV. Prng can start. legic_prng_init(iv); - frame_clean(¤t_frame); - frame_receive_rwd(¤t_frame, 6, 1); - legic_prng_forward(1); /* we wait anyways */ - while(timer->TC_CV < 387) ; /* ~ 258us */ - frame_send_rwd(0x19, 6); + frame_receiveAsReader(¤t_frame, 6); + // fixed delay before sending ack. + WaitTicks(366); // 244us + legic_prng_forward(1); //240us / 100 == 2.4 iterations + + // Send obsfuscated acknowledgment frame. + // 0x19 = 0x18 MIM22, 0x01 LSB READCMD + // 0x39 = 0x38 MIM256, MIM1024 0x01 LSB READCMD + switch ( current_frame.data ) { + case 0x0D: frame_sendAsReader(0x19, 6); break; + case 0x1D: + case 0x3D: frame_sendAsReader(0x39, 6); break; + default: break; + } return current_frame.data; } static void LegicCommonInit(void) { + FpgaDownloadAndGo(FPGA_BITSTREAM_HF); - SetAdcMuxFor(GPIO_MUXSEL_HIPKD); - FpgaSetupSsc(); FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX); + SetAdcMuxFor(GPIO_MUXSEL_HIPKD); /* Bitbang the transmitter */ - AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT; + LOW(GPIO_SSC_DOUT); AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT; AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT; - setup_timer(); + // reserve a cardmem, meaning we can use the tracelog function in bigbuff easier. + cardmem = BigBuf_malloc(LEGIC_CARD_MEMSIZE); + memset(cardmem, 0x00, LEGIC_CARD_MEMSIZE); + clear_trace(); + set_tracing(TRUE); crc_init(&legic_crc, 4, 0x19 >> 1, 0x5, 0); + + StartTicks(); } -static void switch_off_tag_rwd(void) -{ - /* Switch off carrier, make sure tag is reset */ - AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT; - SpinDelay(10); - +// Switch off carrier, make sure tag is reset +static void switch_off_tag_rwd(void) { + LOW(GPIO_SSC_DOUT); + WaitUS(200); WDT_HIT(); + Dbprintf("Exit Switch_off_tag_rwd"); } -/* calculate crc for a legic command */ -static int LegicCRC(int byte_index, int value, int cmd_sz) { - crc_clear(&legic_crc); + +// calculate crc4 for a legic READ command +// 5,8,10 address size. +static uint32_t legic4Crc(uint8_t legicCmd, uint16_t byte_index, uint8_t value, uint8_t cmd_sz) { + crc_clear(&legic_crc); + //uint32_t temp = (value << cmd_sz) | (byte_index << 1) | legicCmd; + //crc_update(&legic_crc, temp, cmd_sz + 8 ); crc_update(&legic_crc, 1, 1); /* CMD_READ */ crc_update(&legic_crc, byte_index, cmd_sz-1); crc_update(&legic_crc, value, 8); @@ -343,165 +431,253 @@ static int LegicCRC(int byte_index, int value, int cmd_sz) { } int legic_read_byte(int byte_index, int cmd_sz) { - int byte; - legic_prng_forward(4); /* we wait anyways */ - while(timer->TC_CV < 387) ; /* ~ 258us + 100us*delay */ + // (us)| ticks + // ------------- + // 330 | 495 + // 460 | 690 + // 258 | 387 + // 244 | 366 + WaitTicks(366); + legic_prng_forward(3); // 460 / 100 = 4.6 iterations + + uint8_t byte = 0, crc = 0, calcCrc = 0; + uint32_t cmd = (byte_index << 1) | LEGIC_READ; - frame_send_rwd(1 | (byte_index << 1), cmd_sz); - frame_clean(¤t_frame); + frame_sendAsReader(cmd, cmd_sz); + frame_receiveAsReader(¤t_frame, 12); - frame_receive_rwd(¤t_frame, 12, 1); + byte = BYTEx(current_frame.data, 0); + calcCrc = legic4Crc(LEGIC_READ, byte_index, byte, cmd_sz); + crc = BYTEx(current_frame.data, 1); - byte = current_frame.data & 0xff; - if( LegicCRC(byte_index, byte, cmd_sz) != (current_frame.data >> 8) ) { - Dbprintf("!!! crc mismatch: expected %x but got %x !!!", - LegicCRC(byte_index, current_frame.data & 0xff, cmd_sz), current_frame.data >> 8); + if( calcCrc != crc ) { + Dbprintf("!!! crc mismatch: expected %x but got %x !!!", calcCrc, crc); return -1; } + +// legic_prng_forward(2); // 460 / 100 = 4.6 iterations return byte; } -/* legic_write_byte() is not included, however it's trivial to implement - * and here are some hints on what remains to be done: - * - * * assemble a write_cmd_frame with crc and send it - * * wait until the tag sends back an ACK ('1' bit unencrypted) - * * forward the prng based on the timing +/* + * - assemble a write_cmd_frame with crc and send it + * - wait until the tag sends back an ACK ('1' bit unencrypted) + * - forward the prng based on the timing */ -int legic_write_byte(int byte, int addr, int addr_sz) { - //do not write UID, CRC, DCF - if(addr <= 0x06) { - return 0; - } +//int legic_write_byte(int byte, int addr, int addr_sz, int PrngCorrection) { +int legic_write_byte(uint8_t byte, uint16_t addr, uint8_t addr_sz) { - //== send write command ============================== + //do not write UID, CRC at offset 0-4. + if (addr <= 4) return 0; + + // crc crc_clear(&legic_crc); crc_update(&legic_crc, 0, 1); /* CMD_WRITE */ crc_update(&legic_crc, addr, addr_sz); crc_update(&legic_crc, byte, 8); - uint32_t crc = crc_finish(&legic_crc); + + uint32_t crc2 = legic4Crc(LEGIC_WRITE, addr, byte, addr_sz+1); + if ( crc != crc2 ) + Dbprintf("crc is missmatch"); + + // send write command uint32_t cmd = ((crc <<(addr_sz+1+8)) //CRC |(byte <<(addr_sz+1)) //Data |(addr <<1) //Address - |(0x00 <<0)); //CMD = W + | LEGIC_WRITE); //CMD = Write + uint32_t cmd_sz = addr_sz+1+8+4; //crc+data+cmd legic_prng_forward(2); /* we wait anyways */ - while(timer->TC_CV < 387) ; /* ~ 258us */ - frame_send_rwd(cmd, cmd_sz); - - //== wait for ack ==================================== - int t, old_level=0, edges=0; - int next_bit_at =0; - while(timer->TC_CV < 387) ; /* ~ 258us */ - for(t=0; t<80; t++) { + + WaitUS(TAG_FRAME_WAIT); + + frame_sendAsReader(cmd, cmd_sz); + + // wllm-rbnt doesnt have these + AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_DIN; + AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DIN; + + // wait for ack + int t, old_level = 0, edges = 0; + int next_bit_at = 0; + + WaitUS(TAG_FRAME_WAIT); + + for( t = 0; t < 80; ++t) { edges = 0; - next_bit_at += TAG_TIME_BIT; + next_bit_at += TAG_BIT_PERIOD; while(timer->TC_CV < next_bit_at) { int level = (AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN); - if(level != old_level) { + if(level != old_level) edges++; - } + old_level = level; } if(edges > 20 && edges < 60) { /* expected are 42 edges */ int t = timer->TC_CV; - int c = t/TAG_TIME_BIT; - timer->TC_CCR = AT91C_TC_SWTRG; - while(timer->TC_CV > 1) ; /* Wait till the clock has reset */ + int c = t / TAG_BIT_PERIOD; + + ResetTimer(timer); legic_prng_forward(c); return 0; } } - timer->TC_CCR = AT91C_TC_SWTRG; - while(timer->TC_CV > 1) ; /* Wait till the clock has reset */ + + ResetTimer(timer); return -1; } -int LegicRfReader(int offset, int bytes) { - int byte_index=0, cmd_sz=0, card_sz=0; - +int LegicRfReader(int offset, int bytes, int iv) { + + uint16_t byte_index = 0; + uint8_t cmd_sz = 0; + int card_sz = 0; + uint8_t isOK = 1; + + if ( MF_DBGLEVEL >= 2) + Dbprintf("setting up legic card, IV = 0x%02x", iv); + LegicCommonInit(); - memset(BigBuf, 0, 1024); + uint32_t tag_type = setup_phase_reader(iv); - DbpString("setting up legic card"); - uint32_t tag_type = perform_setup_phase_rwd(SESSION_IV); - switch_off_tag_rwd(); //we lose to mutch time with dprintf + //we lose to mutch time with dprintf + switch_off_tag_rwd(); + switch(tag_type) { + case 0x0d: + if ( MF_DBGLEVEL >= 2) DbpString("MIM22 card found, reading card"); + cmd_sz = 6; + card_sz = 22; + break; case 0x1d: - DbpString("MIM 256 card found, reading card ..."); + if ( MF_DBGLEVEL >= 2) DbpString("MIM256 card found, reading card"); cmd_sz = 9; card_sz = 256; break; case 0x3d: - DbpString("MIM 1024 card found, reading card ..."); + if ( MF_DBGLEVEL >= 2) DbpString("MIM1024 card found, reading card"); cmd_sz = 11; card_sz = 1024; break; default: - Dbprintf("Unknown card format: %x",tag_type); - return -1; + if ( MF_DBGLEVEL >= 1) Dbprintf("Unknown card format: %x", tag_type); + isOK = 0; + goto OUT; + break; } - if(bytes == -1) { + if (bytes == -1) bytes = card_sz; - } - if(bytes+offset >= card_sz) { - bytes = card_sz-offset; - } - perform_setup_phase_rwd(SESSION_IV); + if (bytes + offset >= card_sz) + bytes = card_sz - offset; + // Start setup and read bytes. + setup_phase_reader(iv); + LED_B_ON(); + while (byte_index < bytes) { + int r = legic_read_byte(byte_index + offset, cmd_sz); + + if (r == -1 || BUTTON_PRESS()) { + if ( MF_DBGLEVEL >= 2) DbpString("operation aborted"); + isOK = 0; + goto OUT; + } + cardmem[++byte_index] = r; + //byte_index++; + WDT_HIT(); + } + +OUT: + switch_off_tag_rwd(); + LEDsoff(); + uint8_t len = (bytes & 0x3FF); + cmd_send(CMD_ACK,isOK,len,0,cardmem,len); + return 0; +} + +/*int _LegicRfWriter(int offset, int bytes, int addr_sz, uint8_t *BigBuf, int RoundBruteforceValue) { + int byte_index=0; + + LED_B_ON(); + setup_phase_reader(iv); + //legic_prng_forward(2); while(byte_index < bytes) { - int r = legic_read_byte(byte_index+offset, cmd_sz); - if(r == -1 ||BUTTON_PRESS()) { - DbpString("operation aborted"); - switch_off_tag_rwd(); - LED_B_OFF(); - LED_C_OFF(); - return -1; + int r; + + //check if the DCF should be changed + if ( (offset == 0x05) && (bytes == 0x02) ) { + //write DCF in reverse order (addr 0x06 before 0x05) + r = legic_write_byte(BigBuf[(0x06-byte_index)], (0x06-byte_index), addr_sz, RoundBruteforceValue); + //legic_prng_forward(1); + if(r == 0) { + byte_index++; + r = legic_write_byte(BigBuf[(0x06-byte_index)], (0x06-byte_index), addr_sz, RoundBruteforceValue); + } + //legic_prng_forward(1); + } + else { + r = legic_write_byte(BigBuf[byte_index+offset], byte_index+offset, addr_sz, RoundBruteforceValue); + } + if((r != 0) || BUTTON_PRESS()) { + Dbprintf("operation aborted @ 0x%03.3x", byte_index); + switch_off_tag_rwd(); + LED_B_OFF(); + LED_C_OFF(); + return -1; } - ((uint8_t*)BigBuf)[byte_index] = r; + WDT_HIT(); byte_index++; - if(byte_index & 0x10) LED_C_ON(); else LED_C_OFF(); + if(byte_index & 0x10) LED_C_ON(); else LED_C_OFF(); } - LED_B_OFF(); + LED_B_OFF(); LED_C_OFF(); - switch_off_tag_rwd(); - Dbprintf("Card read, use 'hf legic decode' or"); - Dbprintf("'data hexsamples %d' to view results", (bytes+7) & ~7); + DbpString("write successful"); return 0; -} +}*/ + +void LegicRfWriter(int offset, int bytes, int iv) { + + int byte_index = 0, addr_sz = 0; -void LegicRfWriter(int bytes, int offset) { - int byte_index=0, addr_sz=0; - LegicCommonInit(); - DbpString("setting up legic card"); - uint32_t tag_type = perform_setup_phase_rwd(SESSION_IV); + if ( MF_DBGLEVEL >= 2) DbpString("setting up legic card"); + + uint32_t tag_type = setup_phase_reader(iv); + switch_off_tag_rwd(); + switch(tag_type) { + case 0x0d: + if(offset+bytes > 22) { + Dbprintf("Error: can not write to 0x%03.3x on MIM22", offset + bytes); + return; + } + addr_sz = 5; + if ( MF_DBGLEVEL >= 2) Dbprintf("MIM22 card found, writing 0x%02.2x - 0x%02.2x ...", offset, offset + bytes); + break; case 0x1d: if(offset+bytes > 0x100) { - Dbprintf("Error: can not write to 0x%03.3x on MIM 256", offset+bytes); + Dbprintf("Error: can not write to 0x%03.3x on MIM256", offset + bytes); return; } addr_sz = 8; - Dbprintf("MIM 256 card found, writing 0x%02.2x - 0x%02.2x ...", offset, offset+bytes); + if ( MF_DBGLEVEL >= 2) Dbprintf("MIM256 card found, writing 0x%02.2x - 0x%02.2x ...", offset, offset + bytes); break; case 0x3d: if(offset+bytes > 0x400) { - Dbprintf("Error: can not write to 0x%03.3x on MIM 1024", offset+bytes); + Dbprintf("Error: can not write to 0x%03.3x on MIM1024", offset + bytes); return; } addr_sz = 10; - Dbprintf("MIM 1024 card found, writing 0x%03.3x - 0x%03.3x ...", offset, offset+bytes); + if ( MF_DBGLEVEL >= 2) Dbprintf("MIM1024 card found, writing 0x%03.3x - 0x%03.3x ...", offset, offset + bytes); break; default: Dbprintf("No or unknown card found, aborting"); @@ -509,70 +685,142 @@ void LegicRfWriter(int bytes, int offset) { } LED_B_ON(); - perform_setup_phase_rwd(SESSION_IV); - legic_prng_forward(2); + setup_phase_reader(iv); + int r = 0; while(byte_index < bytes) { - int r = legic_write_byte(((uint8_t*)BigBuf)[byte_index+offset], byte_index+offset, addr_sz); - if((r != 0) || BUTTON_PRESS()) { + + //check if the DCF should be changed + if ( ((byte_index+offset) == 0x05) && (bytes >= 0x02) ) { + //write DCF in reverse order (addr 0x06 before 0x05) + r = legic_write_byte(cardmem[(0x06-byte_index)], (0x06-byte_index), addr_sz); + + // write second byte on success... + if(r == 0) { + byte_index++; + r = legic_write_byte(cardmem[(0x06-byte_index)], (0x06-byte_index), addr_sz); + } + } + else { + r = legic_write_byte(cardmem[byte_index+offset], byte_index+offset, addr_sz); + } + + if ((r != 0) || BUTTON_PRESS()) { Dbprintf("operation aborted @ 0x%03.3x", byte_index); switch_off_tag_rwd(); - LED_B_OFF(); - LED_C_OFF(); + LEDsoff(); return; } + WDT_HIT(); byte_index++; - if(byte_index & 0x10) LED_C_ON(); else LED_C_OFF(); } - LED_B_OFF(); - LED_C_OFF(); - DbpString("write successful"); + LEDsoff(); + if ( MF_DBGLEVEL >= 1) DbpString("write successful"); } -int timestamp; +void LegicRfRawWriter(int address, int byte, int iv) { + + int byte_index = 0, addr_sz = 0; + + LegicCommonInit(); + + if ( MF_DBGLEVEL >= 2) DbpString("setting up legic card"); + + uint32_t tag_type = setup_phase_reader(iv); + + switch_off_tag_rwd(); + + switch(tag_type) { + case 0x0d: + if(address > 22) { + Dbprintf("Error: can not write to 0x%03.3x on MIM22", address); + return; + } + addr_sz = 5; + if ( MF_DBGLEVEL >= 2) Dbprintf("MIM22 card found, writing at addr 0x%02.2x - value 0x%02.2x ...", address, byte); + break; + case 0x1d: + if(address > 0x100) { + Dbprintf("Error: can not write to 0x%03.3x on MIM256", address); + return; + } + addr_sz = 8; + if ( MF_DBGLEVEL >= 2) Dbprintf("MIM256 card found, writing at addr 0x%02.2x - value 0x%02.2x ...", address, byte); + break; + case 0x3d: + if(address > 0x400) { + Dbprintf("Error: can not write to 0x%03.3x on MIM1024", address); + return; + } + addr_sz = 10; + if ( MF_DBGLEVEL >= 2) Dbprintf("MIM1024 card found, writing at addr 0x%03.3x - value 0x%03.3x ...", address, byte); + break; + default: + Dbprintf("No or unknown card found, aborting"); + return; + } + + Dbprintf("integer value: %d address: %d addr_sz: %d", byte, address, addr_sz); + LED_B_ON(); + + setup_phase_reader(iv); + + int r = legic_write_byte(byte, address, addr_sz); + + if((r != 0) || BUTTON_PRESS()) { + Dbprintf("operation aborted @ 0x%03.3x (%1d)", byte_index, r); + switch_off_tag_rwd(); + LEDsoff(); + return; + } + + LEDsoff(); + if ( MF_DBGLEVEL >= 1) DbpString("write successful"); +} -/* Handle (whether to respond) a frame in tag mode */ +/* Handle (whether to respond) a frame in tag mode + * Only called when simulating a tag. + */ static void frame_handle_tag(struct legic_frame const * const f) { + uint8_t *BigBuf = BigBuf_get_addr(); + /* First Part of Handshake (IV) */ if(f->bits == 7) { - if(f->data == SESSION_IV) { + LED_C_ON(); - prng_timer->TC_CCR = AT91C_TC_SWTRG; + + // Reset prng timer + ResetTimer(prng_timer); + legic_prng_init(f->data); - frame_send_tag(0x3d, 6, 1); /* 0x3d^0x26 = 0x1b */ + frame_send_tag(0x3d, 6, 1); /* 0x3d^0x26 = 0x1B */ legic_state = STATE_IV; legic_read_count = 0; legic_prng_bc = 0; legic_prng_iv = f->data; - /* TIMEOUT */ - timer->TC_CCR = AT91C_TC_SWTRG; - while(timer->TC_CV > 1); - while(timer->TC_CV < 280); - return; - } else if((prng_timer->TC_CV % 50) > 40) { - legic_prng_init(f->data); - frame_send_tag(0x3d, 6, 1); - SpinDelay(20); + + ResetTimer(timer); + WaitUS(280); return; - } } /* 0x19==??? */ if(legic_state == STATE_IV) { - if((f->bits == 6) && (f->data == (0x19 ^ get_key_stream(1, 6)))) { + int local_key = get_key_stream(3, 6); + int xored = 0x39 ^ local_key; + if((f->bits == 6) && (f->data == xored)) { legic_state = STATE_CON; - /* TIMEOUT */ - timer->TC_CCR = AT91C_TC_SWTRG; - while(timer->TC_CV > 1); - while(timer->TC_CV < 200); + ResetTimer(timer); + WaitUS(200); return; - } else { + + } else { legic_state = STATE_DISCON; LED_C_OFF(); - Dbprintf("0x19 - Frame: %03.3x", f->data); + Dbprintf("iv: %02x frame: %02x key: %02x xored: %02x", legic_prng_iv, f->data, local_key, xored); return; } } @@ -580,11 +828,11 @@ static void frame_handle_tag(struct legic_frame const * const f) /* Read */ if(f->bits == 11) { if(legic_state == STATE_CON) { - int key = get_key_stream(-1, 11); //legic_phase_drift, 11); + int key = get_key_stream(2, 11); //legic_phase_drift, 11); int addr = f->data ^ key; addr = addr >> 1; - int data = ((uint8_t*)BigBuf)[addr]; - int hash = LegicCRC(addr, data, 11) << 8; - ((uint8_t*)BigBuf)[OFFSET_LOG+legic_read_count] = (uint8_t)addr; + int data = BigBuf[addr]; + int hash = legic4Crc(LEGIC_READ, addr, data, 11) << 8; + BigBuf[OFFSET_LOG+legic_read_count] = (uint8_t)addr; legic_read_count++; //Dbprintf("Data:%03.3x, key:%03.3x, addr: %03.3x, read_c:%u", f->data, key, addr, read_c); @@ -592,11 +840,9 @@ static void frame_handle_tag(struct legic_frame const * const f) frame_send_tag(hash | data, 12, 1); - /* SHORT TIMEOUT */ - timer->TC_CCR = AT91C_TC_SWTRG; - while(timer->TC_CV > 1); - legic_prng_forward(legic_frame_drift); - while(timer->TC_CV < 180); + ResetTimer(timer); + legic_prng_forward(2); + WaitUS(180); return; } } @@ -619,19 +865,19 @@ static void frame_handle_tag(struct legic_frame const * const f) int i; Dbprintf("IV: %03.3x", legic_prng_iv); for(i = 0; iPIO_ODR = GPIO_SSC_DIN; - AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DIN; - - setup_timer(); - crc_init(&legic_crc, 4, 0x19 >> 1, 0x5, 0); + /* Bitbang the receiver */ + AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_DIN; + AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DIN; + + //setup_timer(); + crc_init(&legic_crc, 4, 0x19 >> 1, 0x5, 0); + + int old_level = 0; + int active = 0; + legic_state = STATE_DISCON; + + LED_B_ON(); + DbpString("Starting Legic emulator, press button to end"); - int old_level = 0; - int active = 0; - legic_state = STATE_DISCON; - - LED_B_ON(); - DbpString("Starting Legic emulator, press button to end"); - while(!BUTTON_PRESS()) { - int level = !!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN); - int time = timer->TC_CV; - - if(level != old_level) { - if(level == 1) { - timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; - if(FUZZ_EQUAL(time, RWD_TIME_1, RWD_TIME_FUZZ)) { - /* 1 bit */ - emit(1); - active = 1; - LED_A_ON(); - } else if(FUZZ_EQUAL(time, RWD_TIME_0, RWD_TIME_FUZZ)) { - /* 0 bit */ - emit(0); - active = 1; - LED_A_ON(); - } else if(active) { - /* invalid */ - emit(-1); - active = 0; - LED_A_OFF(); - } - } - } + while(!BUTTON_PRESS() && !usb_poll_validate_length()) { + int level = !!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN); + int time = timer->TC_CV; + + if(level != old_level) { + if(level == 1) { + timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG; + + if (FUZZ_EQUAL(time, RWD_TIME_1, RWD_TIME_FUZZ)) { + /* 1 bit */ + emit(1); + active = 1; + LED_A_ON(); + } else if (FUZZ_EQUAL(time, RWD_TIME_0, RWD_TIME_FUZZ)) { + /* 0 bit */ + emit(0); + active = 1; + LED_A_ON(); + } else if (active) { + /* invalid */ + emit(-1); + active = 0; + LED_A_OFF(); + } + } + } - if(time >= (RWD_TIME_1+RWD_TIME_FUZZ) && active) { - /* Frame end */ - emit(-1); - active = 0; - LED_A_OFF(); - } - - if(time >= (20*RWD_TIME_1) && (timer->TC_SR & AT91C_TC_CLKSTA)) { - timer->TC_CCR = AT91C_TC_CLKDIS; - } - - old_level = level; - WDT_HIT(); - } - DbpString("Stopped"); - LED_B_OFF(); - LED_A_OFF(); - LED_C_OFF(); + /* Frame end */ + if(time >= (RWD_TIME_1+RWD_TIME_FUZZ) && active) { + emit(-1); + active = 0; + LED_A_OFF(); + } + + if(time >= (20*RWD_TIME_1) && (timer->TC_SR & AT91C_TC_CLKSTA)) { + timer->TC_CCR = AT91C_TC_CLKDIS; + } + + old_level = level; + WDT_HIT(); + } + if ( MF_DBGLEVEL >= 1) DbpString("Stopped"); + LEDsoff(); } +//----------------------------------------------------------------------------- +// Code up a string of octets at layer 2 (including CRC, we don't generate +// that here) so that they can be transmitted to the reader. Doesn't transmit +// them yet, just leaves them ready to send in ToSend[]. +//----------------------------------------------------------------------------- +// static void CodeLegicAsTag(const uint8_t *cmd, int len) +// { + // int i; + + // ToSendReset(); + + // // Transmit a burst of ones, as the initial thing that lets the + // // reader get phase sync. This (TR1) must be > 80/fs, per spec, + // // but tag that I've tried (a Paypass) exceeds that by a fair bit, + // // so I will too. + // for(i = 0; i < 20; i++) { + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // } + + // // Send SOF. + // for(i = 0; i < 10; i++) { + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // } + // for(i = 0; i < 2; i++) { + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // } + + // for(i = 0; i < len; i++) { + // int j; + // uint8_t b = cmd[i]; + + // // Start bit + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // ToSendStuffBit(0); + + // // Data bits + // for(j = 0; j < 8; j++) { + // if(b & 1) { + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // } else { + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // } + // b >>= 1; + // } + + // // Stop bit + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // } + + // // Send EOF. + // for(i = 0; i < 10; i++) { + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // ToSendStuffBit(0); + // } + // for(i = 0; i < 2; i++) { + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // ToSendStuffBit(1); + // } + + // // Convert from last byte pos to length + // ToSendMax++; +// } + +//----------------------------------------------------------------------------- +// The software UART that receives commands from the reader, and its state +// variables. +//----------------------------------------------------------------------------- +static struct { + enum { + STATE_UNSYNCD, + STATE_GOT_FALLING_EDGE_OF_SOF, + STATE_AWAITING_START_BIT, + STATE_RECEIVING_DATA + } state; + uint16_t shiftReg; + int bitCnt; + int byteCnt; + int byteCntMax; + int posCnt; + uint8_t *output; +} Uart; + +/* Receive & handle a bit coming from the reader. + * + * This function is called 4 times per bit (every 2 subcarrier cycles). + * Subcarrier frequency fs is 212kHz, 1/fs = 4,72us, i.e. function is called every 9,44us + * + * LED handling: + * LED A -> ON once we have received the SOF and are expecting the rest. + * LED A -> OFF once we have received EOF or are in error state or unsynced + * + * Returns: true if we received a EOF + * false if we are still waiting for some more + */ +// static RAMFUNC int HandleLegicUartBit(uint8_t bit) +// { + // switch(Uart.state) { + // case STATE_UNSYNCD: + // if(!bit) { + // // we went low, so this could be the beginning of an SOF + // Uart.state = STATE_GOT_FALLING_EDGE_OF_SOF; + // Uart.posCnt = 0; + // Uart.bitCnt = 0; + // } + // break; + + // case STATE_GOT_FALLING_EDGE_OF_SOF: + // Uart.posCnt++; + // if(Uart.posCnt == 2) { // sample every 4 1/fs in the middle of a bit + // if(bit) { + // if(Uart.bitCnt > 9) { + // // we've seen enough consecutive + // // zeros that it's a valid SOF + // Uart.posCnt = 0; + // Uart.byteCnt = 0; + // Uart.state = STATE_AWAITING_START_BIT; + // LED_A_ON(); // Indicate we got a valid SOF + // } else { + // // didn't stay down long enough + // // before going high, error + // Uart.state = STATE_UNSYNCD; + // } + // } else { + // // do nothing, keep waiting + // } + // Uart.bitCnt++; + // } + // if(Uart.posCnt >= 4) Uart.posCnt = 0; + // if(Uart.bitCnt > 12) { + // // Give up if we see too many zeros without + // // a one, too. + // LED_A_OFF(); + // Uart.state = STATE_UNSYNCD; + // } + // break; + + // case STATE_AWAITING_START_BIT: + // Uart.posCnt++; + // if(bit) { + // if(Uart.posCnt > 50/2) { // max 57us between characters = 49 1/fs, max 3 etus after low phase of SOF = 24 1/fs + // // stayed high for too long between + // // characters, error + // Uart.state = STATE_UNSYNCD; + // } + // } else { + // // falling edge, this starts the data byte + // Uart.posCnt = 0; + // Uart.bitCnt = 0; + // Uart.shiftReg = 0; + // Uart.state = STATE_RECEIVING_DATA; + // } + // break; + + // case STATE_RECEIVING_DATA: + // Uart.posCnt++; + // if(Uart.posCnt == 2) { + // // time to sample a bit + // Uart.shiftReg >>= 1; + // if(bit) { + // Uart.shiftReg |= 0x200; + // } + // Uart.bitCnt++; + // } + // if(Uart.posCnt >= 4) { + // Uart.posCnt = 0; + // } + // if(Uart.bitCnt == 10) { + // if((Uart.shiftReg & 0x200) && !(Uart.shiftReg & 0x001)) + // { + // // this is a data byte, with correct + // // start and stop bits + // Uart.output[Uart.byteCnt] = (Uart.shiftReg >> 1) & 0xff; + // Uart.byteCnt++; + + // if(Uart.byteCnt >= Uart.byteCntMax) { + // // Buffer overflowed, give up + // LED_A_OFF(); + // Uart.state = STATE_UNSYNCD; + // } else { + // // so get the next byte now + // Uart.posCnt = 0; + // Uart.state = STATE_AWAITING_START_BIT; + // } + // } else if (Uart.shiftReg == 0x000) { + // // this is an EOF byte + // LED_A_OFF(); // Finished receiving + // Uart.state = STATE_UNSYNCD; + // if (Uart.byteCnt != 0) { + // return TRUE; + // } + // } else { + // // this is an error + // LED_A_OFF(); + // Uart.state = STATE_UNSYNCD; + // } + // } + // break; + + // default: + // LED_A_OFF(); + // Uart.state = STATE_UNSYNCD; + // break; + // } + + // return FALSE; +// } + + +static void UartReset() { + Uart.byteCntMax = 3; + Uart.state = STATE_UNSYNCD; + Uart.byteCnt = 0; + Uart.bitCnt = 0; + Uart.posCnt = 0; + memset(Uart.output, 0x00, 3); +} + +// static void UartInit(uint8_t *data) { + // Uart.output = data; + // UartReset(); +// } + +//============================================================================= +// An LEGIC reader. We take layer two commands, code them +// appropriately, and then send them to the tag. We then listen for the +// tag's response, which we leave in the buffer to be demodulated on the +// PC side. +//============================================================================= + +static struct { + enum { + DEMOD_UNSYNCD, + DEMOD_PHASE_REF_TRAINING, + DEMOD_AWAITING_FALLING_EDGE_OF_SOF, + DEMOD_GOT_FALLING_EDGE_OF_SOF, + DEMOD_AWAITING_START_BIT, + DEMOD_RECEIVING_DATA + } state; + int bitCount; + int posCount; + int thisBit; + uint16_t shiftReg; + uint8_t *output; + int len; + int sumI; + int sumQ; +} Demod; + +/* + * Handles reception of a bit from the tag + * + * This function is called 2 times per bit (every 4 subcarrier cycles). + * Subcarrier frequency fs is 212kHz, 1/fs = 4,72us, i.e. function is called every 9,44us + * + * LED handling: + * LED C -> ON once we have received the SOF and are expecting the rest. + * LED C -> OFF once we have received EOF or are unsynced + * + * Returns: true if we received a EOF + * false if we are still waiting for some more + * + */ + + #ifndef SUBCARRIER_DETECT_THRESHOLD + # define SUBCARRIER_DETECT_THRESHOLD 8 + #endif + + // Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by max(abs(ci),abs(cq)) + 1/2*min(abs(ci),abs(cq))) +#ifndef CHECK_FOR_SUBCARRIER +# define CHECK_FOR_SUBCARRIER() { v = MAX(ai, aq) + MIN(halfci, halfcq); } +#endif + +// The soft decision on the bit uses an estimate of just the +// quadrant of the reference angle, not the exact angle. +// Subcarrier amplitude v = sqrt(ci^2 + cq^2), approximated here by max(abs(ci),abs(cq)) + 1/2*min(abs(ci),abs(cq))) +#define MAKE_SOFT_DECISION() { \ + if(Demod.sumI > 0) \ + v = ci; \ + else \ + v = -ci; \ + \ + if(Demod.sumQ > 0) \ + v += cq; \ + else \ + v -= cq; \ + \ + } + +static RAMFUNC int HandleLegicSamplesDemod(int ci, int cq) +{ + int v = 0; + int ai = ABS(ci); + int aq = ABS(cq); + int halfci = (ai >> 1); + int halfcq = (aq >> 1); + + switch(Demod.state) { + case DEMOD_UNSYNCD: + + CHECK_FOR_SUBCARRIER() + + if(v > SUBCARRIER_DETECT_THRESHOLD) { // subcarrier detected + Demod.state = DEMOD_PHASE_REF_TRAINING; + Demod.sumI = ci; + Demod.sumQ = cq; + Demod.posCount = 1; + } + break; + + case DEMOD_PHASE_REF_TRAINING: + if(Demod.posCount < 8) { + + CHECK_FOR_SUBCARRIER() + + if (v > SUBCARRIER_DETECT_THRESHOLD) { + // set the reference phase (will code a logic '1') by averaging over 32 1/fs. + // note: synchronization time > 80 1/fs + Demod.sumI += ci; + Demod.sumQ += cq; + ++Demod.posCount; + } else { + // subcarrier lost + Demod.state = DEMOD_UNSYNCD; + } + } else { + Demod.state = DEMOD_AWAITING_FALLING_EDGE_OF_SOF; + } + break; + + case DEMOD_AWAITING_FALLING_EDGE_OF_SOF: + + MAKE_SOFT_DECISION() + + //Dbprintf("ICE: %d %d %d %d %d", v, Demod.sumI, Demod.sumQ, ci, cq ); + // logic '0' detected + if (v <= 0) { + + Demod.state = DEMOD_GOT_FALLING_EDGE_OF_SOF; + + // start of SOF sequence + Demod.posCount = 0; + } else { + // maximum length of TR1 = 200 1/fs + if(Demod.posCount > 25*2) Demod.state = DEMOD_UNSYNCD; + } + ++Demod.posCount; + break; + + case DEMOD_GOT_FALLING_EDGE_OF_SOF: + ++Demod.posCount; + + MAKE_SOFT_DECISION() + + if(v > 0) { + // low phase of SOF too short (< 9 etu). Note: spec is >= 10, but FPGA tends to "smear" edges + if(Demod.posCount < 10*2) { + Demod.state = DEMOD_UNSYNCD; + } else { + LED_C_ON(); // Got SOF + Demod.state = DEMOD_AWAITING_START_BIT; + Demod.posCount = 0; + Demod.len = 0; + } + } else { + // low phase of SOF too long (> 12 etu) + if(Demod.posCount > 13*2) { + Demod.state = DEMOD_UNSYNCD; + LED_C_OFF(); + } + } + break; + + case DEMOD_AWAITING_START_BIT: + ++Demod.posCount; + + MAKE_SOFT_DECISION() + + if(v > 0) { + // max 19us between characters = 16 1/fs, max 3 etu after low phase of SOF = 24 1/fs + if(Demod.posCount > 3*2) { + Demod.state = DEMOD_UNSYNCD; + LED_C_OFF(); + } + } else { + // start bit detected + Demod.bitCount = 0; + Demod.posCount = 1; // this was the first half + Demod.thisBit = v; + Demod.shiftReg = 0; + Demod.state = DEMOD_RECEIVING_DATA; + } + break; + + case DEMOD_RECEIVING_DATA: + + MAKE_SOFT_DECISION() + + if(Demod.posCount == 0) { + // first half of bit + Demod.thisBit = v; + Demod.posCount = 1; + } else { + // second half of bit + Demod.thisBit += v; + Demod.shiftReg >>= 1; + // logic '1' + if(Demod.thisBit > 0) + Demod.shiftReg |= 0x200; + + ++Demod.bitCount; + + if(Demod.bitCount == 10) { + + uint16_t s = Demod.shiftReg; + + if((s & 0x200) && !(s & 0x001)) { + // stop bit == '1', start bit == '0' + uint8_t b = (s >> 1); + Demod.output[Demod.len] = b; + ++Demod.len; + Demod.state = DEMOD_AWAITING_START_BIT; + } else { + Demod.state = DEMOD_UNSYNCD; + LED_C_OFF(); + + if(s == 0x000) { + // This is EOF (start, stop and all data bits == '0' + return TRUE; + } + } + } + Demod.posCount = 0; + } + break; + + default: + Demod.state = DEMOD_UNSYNCD; + LED_C_OFF(); + break; + } + return FALSE; +} + +// Clear out the state of the "UART" that receives from the tag. +static void DemodReset() { + Demod.len = 0; + Demod.state = DEMOD_UNSYNCD; + Demod.posCount = 0; + Demod.sumI = 0; + Demod.sumQ = 0; + Demod.bitCount = 0; + Demod.thisBit = 0; + Demod.shiftReg = 0; + memset(Demod.output, 0x00, 3); +} + +static void DemodInit(uint8_t *data) { + Demod.output = data; + DemodReset(); +} + +/* + * Demodulate the samples we received from the tag, also log to tracebuffer + * quiet: set to 'TRUE' to disable debug output + */ + #define LEGIC_DMA_BUFFER_SIZE 256 +static void GetSamplesForLegicDemod(int n, bool quiet) +{ + int max = 0; + bool gotFrame = FALSE; + int lastRxCounter = LEGIC_DMA_BUFFER_SIZE; + int ci, cq, samples = 0; + + BigBuf_free(); + + // And put the FPGA in the appropriate mode + FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_QUARTER_FREQ); + + // The response (tag -> reader) that we're receiving. + // Set up the demodulator for tag -> reader responses. + DemodInit(BigBuf_malloc(MAX_FRAME_SIZE)); + + // The DMA buffer, used to stream samples from the FPGA + int8_t *dmaBuf = (int8_t*) BigBuf_malloc(LEGIC_DMA_BUFFER_SIZE); + int8_t *upTo = dmaBuf; + + // Setup and start DMA. + if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, LEGIC_DMA_BUFFER_SIZE) ){ + if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting"); + return; + } + + // Signal field is ON with the appropriate LED: + LED_D_ON(); + for(;;) { + int behindBy = lastRxCounter - AT91C_BASE_PDC_SSC->PDC_RCR; + if(behindBy > max) max = behindBy; + + while(((lastRxCounter-AT91C_BASE_PDC_SSC->PDC_RCR) & (LEGIC_DMA_BUFFER_SIZE-1)) > 2) { + ci = upTo[0]; + cq = upTo[1]; + upTo += 2; + if(upTo >= dmaBuf + LEGIC_DMA_BUFFER_SIZE) { + upTo = dmaBuf; + AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) upTo; + AT91C_BASE_PDC_SSC->PDC_RNCR = LEGIC_DMA_BUFFER_SIZE; + } + lastRxCounter -= 2; + if(lastRxCounter <= 0) + lastRxCounter = LEGIC_DMA_BUFFER_SIZE; + + samples += 2; + + gotFrame = HandleLegicSamplesDemod(ci , cq ); + if ( gotFrame ) + break; + } + + if(samples > n || gotFrame) + break; + } + + FpgaDisableSscDma(); + + if (!quiet && Demod.len == 0) { + Dbprintf("max behindby = %d, samples = %d, gotFrame = %d, Demod.len = %d, Demod.sumI = %d, Demod.sumQ = %d", + max, + samples, + gotFrame, + Demod.len, + Demod.sumI, + Demod.sumQ + ); + } + + //Tracing + if (Demod.len > 0) { + uint8_t parity[MAX_PARITY_SIZE] = {0x00}; + LogTrace(Demod.output, Demod.len, 0, 0, parity, FALSE); + } +} +//----------------------------------------------------------------------------- +// Transmit the command (to the tag) that was placed in ToSend[]. +//----------------------------------------------------------------------------- +static void TransmitForLegic(void) +{ + int c; + + FpgaSetupSsc(); + + while(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) + AT91C_BASE_SSC->SSC_THR = 0xff; + + // Signal field is ON with the appropriate Red LED + LED_D_ON(); + + // Signal we are transmitting with the Green LED + LED_B_ON(); + FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD); + + for(c = 0; c < 10;) { + if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { + AT91C_BASE_SSC->SSC_THR = 0xff; + c++; + } + if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { + volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR; + (void)r; + } + WDT_HIT(); + } + + c = 0; + for(;;) { + if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) { + AT91C_BASE_SSC->SSC_THR = ToSend[c]; + legic_prng_forward(1); // forward the lfsr + c++; + if(c >= ToSendMax) { + break; + } + } + if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { + volatile uint32_t r = AT91C_BASE_SSC->SSC_RHR; + (void)r; + } + WDT_HIT(); + } + LED_B_OFF(); +} + + +//----------------------------------------------------------------------------- +// Code a layer 2 command (string of octets, including CRC) into ToSend[], +// so that it is ready to transmit to the tag using TransmitForLegic(). +//----------------------------------------------------------------------------- +static void CodeLegicBitsAsReader(const uint8_t *cmd, uint8_t cmdlen, int bits) +{ + int i, j; + uint8_t b; + + ToSendReset(); + + // Send SOF + for(i = 0; i < 7; i++) + ToSendStuffBit(1); + + + for(i = 0; i < cmdlen; i++) { + // Start bit + ToSendStuffBit(0); + + // Data bits + b = cmd[i]; + for(j = 0; j < bits; j++) { + if(b & 1) { + ToSendStuffBit(1); + } else { + ToSendStuffBit(0); + } + b >>= 1; + } + } + + // Convert from last character reference to length + ++ToSendMax; +} + +/** + Convenience function to encode, transmit and trace Legic comms + **/ +static void CodeAndTransmitLegicAsReader(const uint8_t *cmd, uint8_t cmdlen, int bits) +{ + CodeLegicBitsAsReader(cmd, cmdlen, bits); + TransmitForLegic(); + if (tracing) { + uint8_t parity[1] = {0x00}; + LogTrace(cmd, cmdlen, 0, 0, parity, TRUE); + } +} + +int ice_legic_select_card() +{ + //int cmd_size=0, card_size=0; + uint8_t wakeup[] = { 0x7F }; + uint8_t getid[] = {0x19}; + + //legic_prng_init(SESSION_IV); + + // first, wake up the tag, 7bits + CodeAndTransmitLegicAsReader(wakeup, sizeof(wakeup), 7); + + GetSamplesForLegicDemod(1000, TRUE); + + //frame_receiveAsReader(¤t_frame, 6, 1); + + legic_prng_forward(1); /* we wait anyways */ + + //while(timer->TC_CV < 387) ; /* ~ 258us */ + //frame_sendAsReader(0x19, 6); + CodeAndTransmitLegicAsReader(getid, sizeof(getid), 8); + GetSamplesForLegicDemod(1000, TRUE); + + //if (Demod.len < 14) return 2; + Dbprintf("CARD TYPE: %02x LEN: %d", Demod.output[0], Demod.len); + + switch(Demod.output[0]) { + case 0x1d: + DbpString("MIM 256 card found"); + // cmd_size = 9; + // card_size = 256; + break; + case 0x3d: + DbpString("MIM 1024 card found"); + // cmd_size = 11; + // card_size = 1024; + break; + default: + return -1; + } + + // if(bytes == -1) + // bytes = card_size; + + // if(bytes + offset >= card_size) + // bytes = card_size - offset; + + FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF); + set_tracing(FALSE); + return 1; +} + +// Set up LEGIC communication +void ice_legic_setup() { + + // standard things. + FpgaDownloadAndGo(FPGA_BITSTREAM_HF); + BigBuf_free(); BigBuf_Clear_ext(false); + clear_trace(); + set_tracing(TRUE); + DemodReset(); + UartReset(); + + // Set up the synchronous serial port + FpgaSetupSsc(); + + // connect Demodulated Signal to ADC: + SetAdcMuxFor(GPIO_MUXSEL_HIPKD); + + // Signal field is on with the appropriate LED + LED_D_ON(); + FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX | FPGA_HF_READER_TX_SHALLOW_MOD); + SpinDelay(20); + // Start the timer + //StartCountSspClk(); + + // initalize CRC + crc_init(&legic_crc, 4, 0x19 >> 1, 0x5, 0); + + // initalize prng + legic_prng_init(0); +} \ No newline at end of file