X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/da05bc6eca632aa8ef5251942919ab8650191357..27d06e044795c0b0ea4d34b10bccfa41d57f77fc:/armsrc/legicrf.c diff --git a/armsrc/legicrf.c b/armsrc/legicrf.c index a611c741..d3fd35d1 100644 --- a/armsrc/legicrf.c +++ b/armsrc/legicrf.c @@ -1,7 +1,7 @@ //----------------------------------------------------------------------------- // (c) 2009 Henryk Plötz // 2016 Iceman -// 2018 AntiCat (rwd rewritten) +// 2018 AntiCat // // This code is licensed to you under the terms of the GNU GPL, version 2 or, // at your option, any later version. See the LICENSE.txt file for the text of @@ -20,30 +20,8 @@ #include "legic.h" #include "crc.h" -static struct legic_frame { - int bits; - uint32_t data; -} current_frame; - -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 legic_card_select_t card;/* metadata of currently selected card */ +static crc_t legic_crc; //----------------------------------------------------------------------------- // Frame timing and pseudorandom number generator @@ -71,11 +49,6 @@ static uint32_t last_frame_end; /* ts of last bit of previews rx or tx frame */ #define TAG_BIT_PERIOD 150 /* 100us */ #define TAG_WRITE_TIMEOUT 60 /* 40 * 100us (write should take at most 3.6ms) */ -#define SIM_DIVISOR 586 /* prng_time/DIV count prng needs to be forwared */ -#define SIM_SHIFT 900 /* prng_time+SHIFT shift of delayed start */ -#define RWD_TIME_FUZZ 20 /* rather generous 13us, since the peak detector - /+ hysteresis fuzz quite a bit */ - #define LEGIC_READ 0x01 /* Read Command */ #define LEGIC_WRITE 0x00 /* Write Command */ @@ -86,17 +59,15 @@ static uint32_t last_frame_end; /* ts of last bit of previews rx or tx frame */ #define INPUT_THRESHOLD 8 /* heuristically determined, lower values */ /* lead to detecting false ack during write */ -#define FUZZ_EQUAL(value, target, fuzz) ((value) > ((target)-(fuzz)) && (value) < ((target)+(fuzz))) - //----------------------------------------------------------------------------- // I/O interface abstraction (FPGA -> ARM) //----------------------------------------------------------------------------- -static inline uint8_t rx_byte_from_fpga() { +static inline uint16_t rx_frame_from_fpga() { for(;;) { WDT_HIT(); - // wait for byte be become available in rx holding register + // wait for frame be become available in rx holding register if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) { return AT91C_BASE_SSC->SSC_RHR; } @@ -117,33 +88,32 @@ static inline uint8_t rx_byte_from_fpga() { // To reduce CPU time the amplitude is approximated by using linear functions: // am = MAX(ABS(i),ABS(q)) + 1/2*MIN(ABS(i),ABSq)) // -// Note: The SSC receiver is never synchronized the calculation my be performed -// on a I/Q pair from two subsequent correlations, but does not matter. -// // The bit time is 99.1us (21 I/Q pairs). The receiver skips the first 5 samples // and averages the next (most stable) 8 samples. The final 8 samples are dropped // also. // -// The demedulated should be alligned to the bit periode by the caller. This is -// done in rx_bit_as_reader and rx_ack_as_reader. -static inline bool rx_bit_as_reader() { - int32_t cq = 0; - int32_t ci = 0; +// The demodulated should be alligned to the bit period by the caller. This is +// done in rx_bit and rx_ack. +static inline bool rx_bit() { + int32_t sum_cq = 0; + int32_t sum_ci = 0; // skip first 5 I/Q pairs for(size_t i = 0; i<5; ++i) { - (int8_t)rx_byte_from_fpga(); - (int8_t)rx_byte_from_fpga(); + (void)rx_frame_from_fpga(); } // sample next 8 I/Q pairs for(size_t i = 0; i<8; ++i) { - cq += (int8_t)rx_byte_from_fpga(); - ci += (int8_t)rx_byte_from_fpga(); + uint16_t iq = rx_frame_from_fpga(); + int8_t ci = (int8_t)(iq >> 8); + int8_t cq = (int8_t)(iq & 0xff); + sum_ci += ci; + sum_cq += cq; } // calculate power - int32_t power = (MAX(ABS(ci), ABS(cq)) + (MIN(ABS(ci), ABS(cq)) >> 1)); + int32_t power = (MAX(ABS(sum_ci), ABS(sum_cq)) + MIN(ABS(sum_ci), ABS(sum_cq))/2); // compare average (power / 8) to threshold return ((power >> 3) > INPUT_THRESHOLD); @@ -158,14 +128,14 @@ static inline bool rx_bit_as_reader() { // be circumvented, but the adventage over bitbang would be little. //----------------------------------------------------------------------------- -static inline void tx_bit_as_reader(bool bit) { +static inline void tx_bit(bool bit) { // insert pause - LOW(GPIO_SSC_DOUT); + HIGH(GPIO_SSC_DOUT); last_frame_end += RWD_TIME_PAUSE; while(GET_TICKS < last_frame_end) { }; - HIGH(GPIO_SSC_DOUT); - // return to high, wait for bit periode to end + // return to carrier on, wait for bit periode to end + LOW(GPIO_SSC_DOUT); last_frame_end += (bit ? RWD_TIME_1 : RWD_TIME_0) - RWD_TIME_PAUSE; while(GET_TICKS < last_frame_end) { }; } @@ -180,7 +150,7 @@ static inline void tx_bit_as_reader(bool bit) { // present. //----------------------------------------------------------------------------- -static void tx_frame_as_reader(uint32_t frame, uint8_t len) { +static void tx_frame(uint32_t frame, uint8_t len) { FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX); // wait for next tx timeslot @@ -190,18 +160,18 @@ static void tx_frame_as_reader(uint32_t frame, uint8_t len) { // transmit frame, MSB first for(uint8_t i = 0; i < len; ++i) { bool bit = (frame >> i) & 0x01; - tx_bit_as_reader(bit ^ legic_prng_get_bit()); + tx_bit(bit ^ legic_prng_get_bit()); legic_prng_forward(1); }; // add pause to mark end of the frame - LOW(GPIO_SSC_DOUT); + HIGH(GPIO_SSC_DOUT); last_frame_end += RWD_TIME_PAUSE; while(GET_TICKS < last_frame_end) { }; - HIGH(GPIO_SSC_DOUT); + LOW(GPIO_SSC_DOUT); } -static uint32_t rx_frame_as_reader(uint8_t len) { +static uint32_t rx_frame(uint8_t len) { FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ | FPGA_HF_READER_RX_XCORR_QUARTER_FREQ); @@ -211,11 +181,11 @@ static uint32_t rx_frame_as_reader(uint8_t len) { while(GET_TICKS < last_frame_end) { }; uint32_t frame = 0; - for(uint8_t i = 0; i < len; i++) { - frame |= (rx_bit_as_reader() ^ legic_prng_get_bit()) << i; + for(uint8_t i = 0; i < len; ++i) { + frame |= (rx_bit() ^ legic_prng_get_bit()) << i; legic_prng_forward(1); - // rx_bit_as_reader runs only 95us, resync to TAG_BIT_PERIOD + // rx_bit runs only 95us, resync to TAG_BIT_PERIOD last_frame_end += TAG_BIT_PERIOD; while(GET_TICKS < last_frame_end) { }; } @@ -223,7 +193,7 @@ static uint32_t rx_frame_as_reader(uint8_t len) { return frame; } -static bool rx_ack_as_reader() { +static bool rx_ack() { // change fpga into rx mode FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_RX_XCORR | FPGA_HF_READER_RX_XCORR_848_KHZ @@ -236,10 +206,10 @@ static bool rx_ack_as_reader() { uint32_t ack = 0; for(uint8_t i = 0; i < TAG_WRITE_TIMEOUT; ++i) { // sample bit - ack = rx_bit_as_reader(); + ack = rx_bit(); legic_prng_forward(1); - // rx_bit_as_reader runs only 95us, resync to TAG_BIT_PERIOD + // rx_bit runs only 95us, resync to TAG_BIT_PERIOD last_frame_end += TAG_BIT_PERIOD; while(GET_TICKS < last_frame_end) { }; @@ -256,7 +226,7 @@ static bool rx_ack_as_reader() { // Legic Reader //----------------------------------------------------------------------------- -int init_card(uint8_t cardtype, legic_card_select_t *p_card) { +static int init_card(uint8_t cardtype, legic_card_select_t *p_card) { p_card->tagtype = cardtype; switch(p_card->tagtype) { @@ -294,12 +264,12 @@ static void init_reader(bool clear_mem) { LED_D_ON(); // configure SSC with defaults - FpgaSetupSsc(); + FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER_RX_XCORR); // re-claim GPIO_SSC_DOUT as GPIO and enable output AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT; AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT; - HIGH(GPIO_SSC_DOUT); + LOW(GPIO_SSC_DOUT); // init crc calculator crc_init(&legic_crc, 4, 0x19 >> 1, 0x05, 0); @@ -313,8 +283,8 @@ static void init_reader(bool clear_mem) { // The setup consists of a three way handshake: // - Transmit initialisation vector 7 bits // - Receive card type 6 bits -// - Acknowledge frame 6 bits -static uint32_t setup_phase_reader(uint8_t iv) { +// - Transmit Acknowledge 6 bits +static uint32_t setup_phase(uint8_t iv) { // init coordination timestamp last_frame_end = GET_TICKS; @@ -323,24 +293,24 @@ static uint32_t setup_phase_reader(uint8_t iv) { while(GET_TICKS < last_frame_end) { }; legic_prng_init(0); - tx_frame_as_reader(iv, 7); + tx_frame(iv, 7); - // configure iv + // configure prng legic_prng_init(iv); legic_prng_forward(2); // receive card type - int32_t card_type = rx_frame_as_reader(6); + int32_t card_type = rx_frame(6); legic_prng_forward(3); // send obsfuscated acknowledgment frame switch (card_type) { case 0x0D: - tx_frame_as_reader(0x19, 6); // MIM22 | READCMD = 0x18 | 0x01 + tx_frame(0x19, 6); // MIM22 | READCMD = 0x18 | 0x01 break; case 0x1D: case 0x3D: - tx_frame_as_reader(0x39, 6); // MIM256 | READCMD = 0x38 | 0x01 + tx_frame(0x39, 6); // MIM256 | READCMD = 0x38 | 0x01 break; } @@ -359,9 +329,9 @@ static int16_t read_byte(uint16_t index, uint8_t cmd_sz) { // read one byte LED_B_ON(); legic_prng_forward(2); - tx_frame_as_reader(cmd, cmd_sz); + tx_frame(cmd, cmd_sz); legic_prng_forward(2); - uint32_t frame = rx_frame_as_reader(12); + uint32_t frame = rx_frame(12); LED_B_OFF(); // split frame into data and crc @@ -391,12 +361,12 @@ bool write_byte(uint16_t index, uint8_t byte, uint8_t addr_sz) { // send write command LED_C_ON(); legic_prng_forward(2); - tx_frame_as_reader(cmd, addr_sz + 1 + 8 + 4); // sz = addr_sz + cmd + data + crc + tx_frame(cmd, addr_sz + 1 + 8 + 4); // sz = addr_sz + cmd + data + crc legic_prng_forward(3); LED_C_OFF(); // wait for ack - return rx_ack_as_reader(); + return rx_ack(); } //----------------------------------------------------------------------------- @@ -413,7 +383,7 @@ void LegicRfReader(int offset, int bytes) { // establish shared secret and detect card type DbpString("Reading card ..."); - uint8_t card_type = setup_phase_reader(SESSION_IV); + uint8_t card_type = setup_phase(SESSION_IV); if(init_card(card_type, &card) != 0) { Dbprintf("No or unknown card found, aborting"); goto OUT; @@ -463,7 +433,7 @@ void LegicRfWriter(int bytes, int offset) { // establish shared secret and detect card type Dbprintf("Writing 0x%02.2x - 0x%02.2x ...", offset, offset+bytes); - uint8_t card_type = setup_phase_reader(SESSION_IV); + uint8_t card_type = setup_phase(SESSION_IV); if(init_card(card_type, &card) != 0) { Dbprintf("No or unknown card found, aborting"); goto OUT; @@ -476,7 +446,7 @@ void LegicRfWriter(int bytes, int offset) { // write in reverse order, only then is DCF (decremental field) writable while(bytes-- > 0 && !BUTTON_PRESS()) { - if(!write_byte(bytes + offset, BigBuf[bytes], card.addrsize)) { + if(!write_byte(bytes + offset, BigBuf[bytes + offset], card.addrsize)) { Dbprintf("operation failed @ 0x%03.3x", bytes); goto OUT; } @@ -492,345 +462,3 @@ OUT: LED_D_OFF(); StopTicks(); } - -//----------------------------------------------------------------------------- -// Legic Simulator -//----------------------------------------------------------------------------- - -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 - */ - 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; -} - -/* 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 */ - uint8_t *BigBuf = BigBuf_get_addr(); - if(count == 6) { i = -1; } else { i = legic_read_count; } - 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; iTC_CV < (TAG_FRAME_WAIT - 30)) ; - - int i; - for(i=0; iTC_CV + TAG_BIT_PERIOD; - 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; -} - -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; -} - -/* Handle (whether to respond) a frame in tag mode */ -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; - 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 = BigBuf[addr]; - int hash = calc_crc4(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); - 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; iPIO_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(); -} -