-/*
- * LEGIC RF simulation code
- *
- * (c) 2009 Henryk Plötz <henryk@ploetzli.ch>
- */
-
-#include <proxmark3.h>
+//-----------------------------------------------------------------------------
+// (c) 2009 Henryk Plötz <henryk@ploetzli.ch>
+//
+// 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
+// the license.
+//-----------------------------------------------------------------------------
+// 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 num_bytes;
- int num_bits;
- char data[10];
+ int bits;
+ uint32_t data;
} current_frame;
-static char queries[][4] = {
- {7, 0x55}, /* 1010 101 */
-};
-static char responses[][4] = {
- {6, 0x3b}, /* 1101 11 */
-};
+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;
-static void frame_send(char *response, int num_bytes, int num_bits)
+AT91PS_TC timer;
+AT91PS_TC prng_timer;
+
+static void setup_timer(void)
{
-#if 0
- /* Use the SSC to send a response. 8-bit transfers, LSBit first, 100us per bit */
-#else
- /* 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;
-
- /* Wait for the frame start */
- while(AT91C_BASE_TC1->TC_CV < 490) ;
-
- int i;
- for(i=0; i<(num_bytes*8+num_bits); i++) {
- int nextbit = AT91C_BASE_TC1->TC_CV + 150;
- int bit = response[i/8] & (1<<(i%8));
- if(bit)
- AT91C_BASE_PIOA->PIO_SODR = GPIO_SSC_DOUT;
- else
- AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT;
- while(AT91C_BASE_TC1->TC_CV < nextbit) ;
- }
- AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT;
-#endif
+ /* 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;
}
-static void frame_respond(struct legic_frame *f)
+/* 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 */
+
+#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)
{
- LED_D_ON();
- int bitcount = f->num_bytes*8+f->num_bits;
- int i, r=-1;
- for(i=0; i<sizeof(queries)/sizeof(queries[0]); i++) {
- if(bitcount == queries[i][0] && f->data[0] == queries[i][1] && f->data[1] == queries[i][2]) {
- r = i;
- break;
- }
- }
-
- if(r != -1) {
- frame_send(&responses[r][1], responses[r][0]/8, responses[r][0]%8);
- LED_A_ON();
+ 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 {
- LED_A_OFF();
+ legic_prng_forward(skip);
}
-
- LED_D_OFF();
+
+ /* Write Time Data into LOG */
+ uint8_t *BigBuf = BigBuf_get_addr();
+ i = (count == 6) ? -1 : 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; i<count; i++) {
+ key |= legic_prng_get_bit() << i;
+ legic_prng_forward(1);
+ }
+ return key;
}
-static void frame_append_bit(struct legic_frame *f, int bit)
+/* 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)
{
- if(f->num_bytes >= (int)sizeof(f->data))
- return; /* Overflow, won't happen */
- f->data[f->num_bytes] |= (bit<<f->num_bits);
- f->num_bits++;
- if(f->num_bits > 7) {
- f->num_bits = 0;
- f->num_bytes++;
- }
+ /* 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;
}
-static int frame_is_empty(struct legic_frame *f)
+/* 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)
{
- return( (f->num_bytes*8 + f->num_bits) <= 4 );
+ /* Start clock */
+ timer->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
+ while(timer->TC_CV > 1) ; /* Wait till the clock has reset */
+
+ int i;
+ for(i=0; i<bits; i++) {
+ int starttime = timer->TC_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;
+ else
+ bit_end = starttime + 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 */
}
-static void frame_handle(struct legic_frame *f)
+/* 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.
+ *
+ * The LEGIC RF protocol from card to reader does not include explicit
+ * frame start/stop information or length information. The reader must
+ * know beforehand how many bits it wants to receive. (Notably: a card
+ * sending a stream of 0-bits is indistinguishable from no card present.)
+ *
+ * Receive methodology: There is a fancy correlator in hi_read_rx_xcorr, but
+ * I'm not smart enough to use it. Instead I have patched hi_read_tx to output
+ * the ADC signal with hysteresis on SSP_DIN. Bit-bang that signal and look
+ * 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
+ * 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)
{
- if(f->num_bytes == 0 && f->num_bits == 6) {
- /* Short path */
- return;
+ 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;
+ }
+
+ 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 */
+ legic_prng_forward(2);
+
+ if(crypt) {
+ for(i=0; i<bits; i++) {
+ data |= legic_prng_get_bit() << i;
+ legic_prng_forward(1);
+ }
}
- if( !frame_is_empty(f) ) {
- frame_respond(f);
+
+ while(timer->TC_CV < next_bit_at) ;
+
+ next_bit_at += TAG_TIME_BIT;
+
+ 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)
+ edges++;
+ old_level = level;
+ }
+ next_bit_at += TAG_TIME_BIT;
+
+ if(edges > 20 && edges < 60) { /* expected are 42 edges */
+ data ^= the_bit;
+ }
+ the_bit <<= 1;
}
+
+ 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_clean(struct legic_frame *f)
+static void frame_append_bit(struct legic_frame * const f, int bit)
{
- if(!frame_is_empty(f))
- /* memset(f->data, 0, sizeof(f->data)); */
- f->data[0] = f->data[1] = 0;
- f->num_bits = 0;
- f->num_bytes = 0;
+ if (f->bits >= 31)
+ return; /* Overflow, won't happen */
+
+ f->data |= (bit << f->bits);
+ f->bits++;
}
-static void emit(int bit)
+static void frame_clean(struct legic_frame * const f)
{
- if(bit == -1) {
- frame_handle(¤t_frame);
- frame_clean(¤t_frame);
- } else if(bit == 0) {
- frame_append_bit(¤t_frame, 0);
- } else if(bit == 1) {
- frame_append_bit(¤t_frame, 1);
- }
+ f->data = 0;
+ f->bits = 0;
}
-void LegicRfSimulate(void)
+static uint32_t perform_setup_phase_rwd(int iv)
{
- /* 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.
- */
+
+ /* Switch on carrier and let the tag charge for 1ms */
+ AT91C_BASE_PIOA->PIO_SODR = GPIO_SSC_DOUT;
+ SpinDelay(1);
+
+ legic_prng_init(0); /* no keystream yet */
+ frame_send_rwd(iv, 7);
+ 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);
+
+ return current_frame.data;
+}
+
+static void LegicCommonInit(void) {
+ FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
FpgaSetupSsc();
- FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_212K);
-
- /* Bitbang the receiver */
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX);
+
+ /* Bitbang the transmitter */
+ AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT;
+ AT91C_BASE_PIOA->PIO_OER = GPIO_SSC_DOUT;
+ AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DOUT;
+
+ setup_timer();
+
+ crc_init(&legic_crc, 4, 0x19 >> 1, 0x5, 0);
+}
+
+/* Switch off carrier, make sure tag is reset */
+static void switch_off_tag_rwd(void)
+{
+ AT91C_BASE_PIOA->PIO_CODR = GPIO_SSC_DOUT;
+ SpinDelay(10);
+ WDT_HIT();
+}
+/* calculate crc for a legic command */
+static int LegicCRC(int byte_index, int value, int cmd_sz) {
+ crc_clear(&legic_crc);
+ crc_update(&legic_crc, 1, 1); /* CMD_READ */
+ crc_update(&legic_crc, byte_index, cmd_sz-1);
+ crc_update(&legic_crc, value, 8);
+ return crc_finish(&legic_crc);
+}
+
+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 */
+
+ frame_send_rwd(1 | (byte_index << 1), cmd_sz);
+ frame_clean(¤t_frame);
+
+ frame_receive_rwd(¤t_frame, 12, 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);
+ return -1;
+ }
+
+ 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
+ */
+//int legic_write_byte(int byte, int addr, int addr_sz, int PrngCorrection) {
+int legic_write_byte(int byte, int addr, int addr_sz) {
+ //do not write UID, CRC
+ if(addr <= 0x04) {
+ 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(4); /* we wait anyways */
+ while(timer->TC_CV < 387) ; /* ~ 258us */
+ frame_send_rwd(cmd, cmd_sz);
+
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;
+ 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-1);
+ return 0;
+ }
+ }
+ timer->TC_CCR = AT91C_TC_SWTRG;
+ while(timer->TC_CV > 1) ; /* Wait till the clock has reset */
+ return -1;
+}
+
+int LegicRfReader(int offset, int bytes) {
- /* 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);
- AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS;
- AT91C_BASE_TC1->TC_CMR = TC_CMR_TCCLKS_TIMER_CLOCK3;
- AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
- int old_level = 0;
+ // ice_legic_setup();
+ // ice_legic_select_card();
+ // return 0;
+
+ int byte_index=0, cmd_sz=0, card_sz=0;
-/* At TIMER_CLOCK3 (MCK/32) */
-#define BIT_TIME_1 150
-#define BIT_TIME_0 90
-#define BIT_TIME_FUZZ 20
+ LegicCommonInit();
+
+ uint8_t *BigBuf = BigBuf_get_addr();
+ memset(BigBuf, 0, 1024);
+
+ 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
+ switch(tag_type) {
+ case 0x0d:
+ DbpString("MIM22 card found, reading card ...");
+ cmd_sz = 6;
+ card_sz = 22;
+ break;
+ case 0x1d:
+ DbpString("MIM256 card found, reading card ...");
+ cmd_sz = 9;
+ card_sz = 256;
+ break;
+ case 0x3d:
+ DbpString("MIM1024 card found, reading card ...");
+ cmd_sz = 11;
+ card_sz = 1024;
+ break;
+ default:
+ Dbprintf("Unknown card format: %x",tag_type);
+ return -1;
+ }
+ if(bytes == -1)
+ bytes = card_sz;
+
+ if(bytes+offset >= card_sz)
+ bytes = card_sz-offset;
+
+ 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 ||BUTTON_PRESS()) {
+ DbpString("operation aborted");
+ switch_off_tag_rwd();
+ LED_B_OFF();
+ LED_C_OFF();
+ return -1;
+ }
+ 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;
+}
+
+/*int _LegicRfWriter(int bytes, int offset, int addr_sz, uint8_t *BigBuf, int RoundBruteforceValue) {
+ int byte_index=0;
+
+ LED_B_ON();
+ perform_setup_phase_rwd(SESSION_IV);
+ //legic_prng_forward(2);
+ while(byte_index < bytes) {
+ 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;
+ }
+
+ WDT_HIT();
+ byte_index++;
+ if(byte_index & 0x10) LED_C_ON(); else LED_C_OFF();
+ }
+ LED_B_OFF();
+ LED_C_OFF();
+ DbpString("write successful");
+ return 0;
+}*/
+
+void LegicRfWriter(int bytes, int offset) {
+ int byte_index=0, addr_sz=0;
+ uint8_t *BigBuf = BigBuf_get_addr();
+
+ LegicCommonInit();
- int active = 0;
- while(!BUTTON_PRESS()) {
- int level = !!(AT91C_BASE_PIOA->PIO_PDSR & GPIO_SSC_DIN);
- int time = AT91C_BASE_TC1->TC_CV;
-
- if(level != old_level) {
- if(level == 1) {
- AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKEN | AT91C_TC_SWTRG;
- if(time > (BIT_TIME_1-BIT_TIME_FUZZ) && time < (BIT_TIME_1+BIT_TIME_FUZZ)) {
- /* 1 bit */
- emit(1);
- active = 1;
- LED_B_ON();
- } else if(time > (BIT_TIME_0-BIT_TIME_FUZZ) && time < (BIT_TIME_0+BIT_TIME_FUZZ)) {
- /* 0 bit */
- emit(0);
- active = 1;
- LED_B_ON();
- } else if(active) {
- /* invalid */
- emit(-1);
- active = 0;
- LED_B_OFF();
- }
+ DbpString("setting up legic card");
+ uint32_t tag_type = perform_setup_phase_rwd(SESSION_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;
+ 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 MIM256", offset+bytes);
+ return;
+ }
+ addr_sz = 8;
+ 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 MIM1024", offset+bytes);
+ return;
+ }
+ addr_sz = 10;
+ Dbprintf("MIM1024 card found, writing 0x%03.3x - 0x%03.3x ...", offset, offset+bytes);
+ break;
+ default:
+ Dbprintf("No or unknown card found, aborting");
+ return;
+ }
+
+#if 1
+ LED_B_ON();
+ perform_setup_phase_rwd(SESSION_IV);
+
+ while(byte_index < bytes) {
+ int r;
+
+ //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(BigBuf[(0x06-byte_index)], (0x06-byte_index), addr_sz);
+
+ // write second byte on success...
+ if(r == 0) {
+ byte_index++;
+ r = legic_write_byte(BigBuf[(0x06-byte_index)], (0x06-byte_index), addr_sz);
}
}
-
- if(time >= (BIT_TIME_1+BIT_TIME_FUZZ) && active) {
- /* Frame end */
- emit(-1);
- active = 0;
+ else {
+ r = legic_write_byte(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");
+#else
+ for(byte_index = -2; byte_index < 200; byte_index++)
+ {
+ Dbprintf("+ Try RndValue %d...", byte_index);
+ if(_LegicRfWriter(bytes, offset, addr_sz, BigBuf, byte_index) == 0)
+ break;
+ }
+#endif
+
+}
+
+void LegicRfRawWriter(int offset, int byte) {
+ 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();
+ switch(tag_type) {
+ case 0x0d:
+ if(offset > 22) {
+ Dbprintf("Error: can not write to 0x%03.3x on MIM22", offset);
+ return;
+ }
+ addr_sz = 5;
+ Dbprintf("MIM22 card found, writing at addr 0x%02.2x - value 0x%02.2x ...", offset, byte);
+ break;
+ case 0x1d:
+ if(offset > 0x100) {
+ Dbprintf("Error: can not write to 0x%03.3x on MIM256", offset);
+ return;
+ }
+ addr_sz = 8;
+ Dbprintf("MIM256 card found, writing at addr 0x%02.2x - value 0x%02.2x ...", offset, byte);
+ break;
+ case 0x3d:
+ if(offset > 0x400) {
+ Dbprintf("Error: can not write to 0x%03.3x on MIM1024", offset);
+ return;
+ }
+ addr_sz = 10;
+ Dbprintf("MIM1024 card found, writing at addr 0x%03.3x - value 0x%03.3x ...", offset, byte);
+ break;
+ default:
+ Dbprintf("No or unknown card found, aborting");
+ return;
+ }
+ Dbprintf("integer value: %d offset: %d addr_sz: %d", byte, offset, addr_sz);
+ LED_B_ON();
+ perform_setup_phase_rwd(SESSION_IV);
+ //legic_prng_forward(2);
- if(time >= (20*BIT_TIME_1) && (AT91C_BASE_TC1->TC_SR & AT91C_TC_CLKSTA)) {
- AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS;
- }
+ int r = legic_write_byte(byte, offset, addr_sz);
+ if((r != 0) || BUTTON_PRESS()) {
+ Dbprintf("operation aborted @ 0x%03.3x (%1d)", byte_index, r);
+ 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)
+{
+ 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 = LegicCRC(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; i<legic_read_count; i++) {
+ Dbprintf("Read Nb: %u, Addr: %u", i, BigBuf[OFFSET_LOG+i]);
+ }
+
+ for(i = -1; i<legic_read_count; i++) {
+ uint32_t t;
+ t = BigBuf[OFFSET_LOG+256+i*4];
+ t |= BigBuf[OFFSET_LOG+256+i*4+1] << 8;
+ t |= BigBuf[OFFSET_LOG+256+i*4+2] <<16;
+ t |= BigBuf[OFFSET_LOG+256+i*4+3] <<24;
+
+ Dbprintf("Cycles: %u, Frame Length: %u, Time: %u",
+ BigBuf[OFFSET_LOG+128+i],
+ 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;
+
+ FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
+ 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() && !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();
+}
+
+
+//-----------------------------------------------------------------------------
+//-----------------------------------------------------------------------------
+
+
+//-----------------------------------------------------------------------------
+// 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 = MAX_FRAME_SIZE;
+ Uart.state = STATE_UNSYNCD;
+ Uart.byteCnt = 0;
+ Uart.bitCnt = 0;
+ Uart.posCnt = 0;
+ memset(Uart.output, 0x00, MAX_FRAME_SIZE);
+}
+
+// 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:
- old_level = level;
+ 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, MAX_FRAME_SIZE);
+}
+
+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, bits, 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_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);
+ 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(200);
+ // 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
projects / proxmark3-svn / blobdiff