X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/0aa4cfc2f15d99f84929066c879bcdbb8d8ba81f..759c16b31f8dcec37458dd6a5973ce0cfce58015:/armsrc/legicrf.c?ds=inline diff --git a/armsrc/legicrf.c b/armsrc/legicrf.c index 313ac3c9..f2eb680b 100644 --- a/armsrc/legicrf.c +++ b/armsrc/legicrf.c @@ -22,9 +22,23 @@ static struct legic_frame { uint32_t data; } current_frame; -static crc_t legic_crc; +static enum { + STATE_DISCON, + STATE_IV, + STATE_CON, +} legic_state; + +static crc_t legic_crc; +static int legic_read_count; +static uint32_t legic_prng_bc; +static uint32_t legic_prng_iv; + +static int legic_phase_drift; +static int legic_frame_drift; +static int legic_reqresp_drift; AT91PS_TC timer; +AT91PS_TC prng_timer; static void setup_timer(void) { @@ -37,6 +51,17 @@ static void setup_timer(void) 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 + */ + AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC2); + prng_timer = AT91C_BASE_TC2; + prng_timer->TC_CCR = AT91C_TC_CLKDIS; + prng_timer->TC_CMR = AT91C_TC_CLKS_TIMER_DIV2_CLOCK; + 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 */ @@ -45,10 +70,90 @@ static void setup_timer(void) #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 */ -} +#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))) +/* 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; i<count; i++) { + key |= legic_prng_get_bit() << i; + legic_prng_forward(1); + } + return key; +} + +/* Send a frame in tag mode, the FPGA must have been set up by + * LegicRfSimulate + */ +static void frame_send_tag(uint16_t response, int bits, int crypt) +{ + /* Bitbang the response */ + AT91C_BASE_PIOA->PIO_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; i<bits; i++) { + key |= legic_prng_get_bit() << i; + legic_prng_forward(1); + } + //Dbprintf("key = 0x%x", key); + response = response ^ key; + } + + /* Wait for the frame start */ + while(timer->TC_CV < (TAG_TIME_WAIT - 30)) ; + + int i; + for(i=0; i<bits; i++) { + int nextbit = timer->TC_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) ; + } + AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT; +} + /* Send a frame in reader mode, the FPGA must have been set up by * LegicRfReader */ @@ -121,16 +226,16 @@ static void frame_receive_rwd(struct legic_frame * const f, int bits, int crypt) uint32_t data=0; int i, old_level=0, edges=0; int next_bit_at = TAG_TIME_WAIT; - - - if(bits > 16) - bits = 16; + + if(bits > 32) { + bits = 32; + } 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 */ + * since we cannot compute it on the fly while reading */ legic_prng_forward(2); if(crypt) @@ -147,7 +252,6 @@ static void frame_receive_rwd(struct legic_frame * const f, int bits, int crypt) for(i=0; i<bits; i++) { edges = 0; - while(timer->TC_CV < next_bit_at) { int level = (AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN); if(level != old_level) @@ -155,11 +259,10 @@ static void frame_receive_rwd(struct legic_frame * const f, int bits, int crypt) old_level = level; } next_bit_at += TAG_TIME_BIT; - + if(edges > 20 && edges < 60) { /* expected are 42 edges */ data ^= the_bit; } - the_bit <<= 1; } @@ -171,6 +274,15 @@ static void frame_receive_rwd(struct legic_frame * const f, int bits, int crypt) 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<<f->bits); + f->bits++; +} + static void frame_clean(struct legic_frame * const f) { f->data = 0; @@ -186,7 +298,7 @@ static uint32_t perform_setup_phase_rwd(int iv) legic_prng_init(0); /* no keystream yet */ frame_send_rwd(iv, 7); - legic_prng_init(iv); + legic_prng_init(iv); frame_clean(¤t_frame); frame_receive_rwd(¤t_frame, 6, 1); @@ -233,7 +345,7 @@ 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 */ + while(timer->TC_CV < 387) ; /* ~ 258us + 100us*delay */ frame_send_rwd(1 | (byte_index << 1), cmd_sz); frame_clean(¤t_frame); @@ -242,7 +354,8 @@ int legic_read_byte(int byte_index, int cmd_sz) { 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); + Dbprintf("!!! crc mismatch: expected %x but got %x !!!", + LegicCRC(byte_index, current_frame.data & 0xff, cmd_sz), current_frame.data >> 8); return -1; } @@ -256,9 +369,58 @@ int legic_read_byte(int byte_index, int cmd_sz) { * * 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; + } + //== send write command ============================== + 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 cmd = ((crc <<(addr_sz+1+8)) //CRC + |(byte <<(addr_sz+1)) //Data + |(addr <<1) //Address + |(0x00 <<0)); //CMD = W + 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++) { + edges = 0; + next_bit_at += TAG_TIME_BIT; + while(timer->TC_CV < next_bit_at) { + int level = (AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN); + 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 */ + legic_prng_forward(c); + return 0; + } + } + timer->TC_CCR = AT91C_TC_SWTRG; + while(timer->TC_CV > 1) ; /* Wait till the clock has reset */ + return -1; +} -void LegicRfReader(int offset, int bytes) { +int LegicRfReader(int offset, int bytes) { int byte_index=0, cmd_sz=0, card_sz=0; LegicCommonInit(); @@ -266,44 +428,325 @@ void LegicRfReader(int offset, int bytes) { memset(BigBuf, 0, 1024); DbpString("setting up legic card"); - uint32_t tag_type = perform_setup_phase_rwd(0x55); + uint32_t tag_type = perform_setup_phase_rwd(SESSION_IV); + switch_off_tag_rwd(); //we lose to mutch time with dprintf switch(tag_type) { case 0x1d: DbpString("MIM 256 card found, reading card ..."); - cmd_sz = 9; + cmd_sz = 9; card_sz = 256; break; case 0x3d: DbpString("MIM 1024 card found, reading card ..."); - cmd_sz = 11; + cmd_sz = 11; card_sz = 1024; break; default: Dbprintf("Unknown card format: %x",tag_type); - switch_off_tag_rwd(); - return; + return -1; } if(bytes == -1) { bytes = card_sz; } - if(bytes+offset >= card_sz) { + if(bytes+offset >= card_sz) { bytes = card_sz-offset; - } + } - switch_off_tag_rwd(); //we lost to mutch time with dprintf - perform_setup_phase_rwd(0x55); + perform_setup_phase_rwd(SESSION_IV); + LED_B_ON(); while(byte_index < bytes) { - int r = legic_read_byte(byte_index+offset, cmd_sz); - if(r == -1) { - Dbprintf("aborting"); + int r = legic_read_byte(byte_index+offset, cmd_sz); + if(r == -1 ||BUTTON_PRESS()) { + DbpString("operation aborted"); switch_off_tag_rwd(); - return; + 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(); } + 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); + return 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); switch_off_tag_rwd(); - Dbprintf("Card read, use 'hf legic decode' or 'data hexsamples %d' to view results", (bytes+7) & ~7); + switch(tag_type) { + case 0x1d: + if(offset+bytes > 0x100) { + Dbprintf("Error: can not write to 0x%03.3x on MIM 256", offset+bytes); + return; + } + addr_sz = 8; + Dbprintf("MIM 256 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); + return; + } + addr_sz = 10; + Dbprintf("MIM 1024 card found, writing 0x%03.3x - 0x%03.3x ...", offset, offset+bytes); + break; + default: + Dbprintf("No or unknown card found, aborting"); + return; + } + + LED_B_ON(); + perform_setup_phase_rwd(SESSION_IV); + legic_prng_forward(2); + 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()) { + Dbprintf("operation aborted @ 0x%03.3x", byte_index); + switch_off_tag_rwd(); + LED_B_OFF(); + LED_C_OFF(); + 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"); +} + +int timestamp; + +/* Handle (whether to respond) a frame in tag mode */ +static void frame_handle_tag(struct legic_frame const * const f) +{ + /* First Part of Handshake (IV) */ + if(f->bits == 7) { + if(f->data == SESSION_IV) { + LED_C_ON(); + prng_timer->TC_CCR = AT91C_TC_SWTRG; + legic_prng_init(f->data); + 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); + return; + } + } + + /* 0x19==??? */ + if(legic_state == STATE_IV) { + if((f->bits == 6) && (f->data == (0x19 ^ get_key_stream(1, 6)))) { + legic_state = STATE_CON; + + /* TIMEOUT */ + timer->TC_CCR = AT91C_TC_SWTRG; + while(timer->TC_CV > 1); + while(timer->TC_CV < 200); + return; + } else { + legic_state = STATE_DISCON; + LED_C_OFF(); + Dbprintf("0x19 - Frame: %03.3x", f->data); + return; + } + } + + /* Read */ + if(f->bits == 11) { + if(legic_state == STATE_CON) { + int key = get_key_stream(-1, 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; + legic_read_count++; + + //Dbprintf("Data:%03.3x, key:%03.3x, addr: %03.3x, read_c:%u", f->data, key, addr, read_c); + legic_prng_forward(legic_reqresp_drift); + + 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); + return; + } + } + + /* Write */ + if(f->bits == 23) { + int key = get_key_stream(-1, 23); //legic_frame_drift, 23); + int addr = f->data ^ key; addr = addr >> 1; addr = addr & 0x3ff; + int data = f->data ^ key; data = data >> 11; data = data & 0xff; + + /* write command */ + legic_state = STATE_DISCON; + LED_C_OFF(); + Dbprintf("write - addr: %x, data: %x", addr, data); + return; + } + + if(legic_state != STATE_DISCON) { + Dbprintf("Unexpected: sz:%u, Data:%03.3x, State:%u, Count:%u", f->bits, f->data, legic_state, legic_read_count); + int i; + Dbprintf("IV: %03.3x", legic_prng_iv); + for(i = 0; i<legic_read_count; i++) { + Dbprintf("Read Nb: %u, Addr: %u", i, ((uint8_t*)BigBuf)[OFFSET_LOG+i]); + } + + for(i = -1; i<legic_read_count; i++) { + uint32_t t; + t = ((uint8_t*)BigBuf)[OFFSET_LOG+256+i*4]; + t |= ((uint8_t*)BigBuf)[OFFSET_LOG+256+i*4+1] << 8; + t |= ((uint8_t*)BigBuf)[OFFSET_LOG+256+i*4+2] <<16; + t |= ((uint8_t*)BigBuf)[OFFSET_LOG+256+i*4+3] <<24; + + Dbprintf("Cycles: %u, Frame Length: %u, Time: %u", + ((uint8_t*)BigBuf)[OFFSET_LOG+128+i], + ((uint8_t*)BigBuf)[OFFSET_LOG+384+i], + t); + } + } + legic_state = STATE_DISCON; + legic_read_count = 0; + SpinDelay(10); + LED_C_OFF(); + return; +} + +/* Read bit by bit untill full frame is received + * Call to process frame end answer + */ +static void emit(int bit) +{ + if(bit == -1) { + if(current_frame.bits <= 4) { + frame_clean(¤t_frame); + } else { + frame_handle_tag(¤t_frame); + frame_clean(¤t_frame); + } + WDT_HIT(); + } else if(bit == 0) { + frame_append_bit(¤t_frame, 0); + } else if(bit == 1) { + frame_append_bit(¤t_frame, 1); + } +} + +void LegicRfSimulate(int phase, int frame, int reqresp) +{ + /* ADC path high-frequency peak detector, FPGA in high-frequency simulator mode, + * modulation mode set to 212kHz subcarrier. We are getting the incoming raw + * envelope waveform on DIN and should send our response on DOUT. + * + * The LEGIC RF protocol is pulse-pause-encoding from reader to card, so we'll + * measure the time between two rising edges on DIN, and no encoding on the + * subcarrier from card to reader, so we'll just shift out our verbatim data + * on DOUT, 1 bit is 100us. The time from reader to card frame is still unclear, + * seems to be 300us-ish. + */ + + if(phase < 0) { + int i; + for(i=0; i<=reqresp; i++) { + legic_prng_init(SESSION_IV); + Dbprintf("i=%u, key 0x%3.3x", i, get_key_stream(i, frame)); + } + return; + } + + legic_phase_drift = phase; + legic_frame_drift = frame; + legic_reqresp_drift = reqresp; + + SetAdcMuxFor(GPIO_MUXSEL_HIPKD); + FpgaSetupSsc(); + FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_212K); + + /* 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"); + 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(); + } + } + } + + 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(); }