-/*
- * 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;
+
+AT91PS_TC timer;
+AT91PS_TC prng_timer;
-static void frame_send(char *response, int num_bytes, int num_bits)
+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();
- } else {
- LED_A_OFF();
- }
-
- LED_D_OFF();
+ 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; 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 */
- AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_DIN;
- AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DIN;
-
- /* 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;
+ FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER_TX);
-/* At TIMER_CLOCK3 (MCK/32) */
-#define BIT_TIME_1 150
-#define BIT_TIME_0 90
-#define BIT_TIME_FUZZ 20
-
- 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();
- }
+ /* 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);
+}
+
+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);
+
+ 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) {
+ //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;
+}
+
+int LegicRfReader(int offset, int bytes) {
+ int byte_index=0, cmd_sz=0, card_sz=0;
+
+ 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 0x1d:
+ DbpString("MIM 256 card found, reading card ...");
+ cmd_sz = 9;
+ card_sz = 256;
+ break;
+ case 0x3d:
+ DbpString("MIM 1024 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;
}
-
- if(time >= (BIT_TIME_1+BIT_TIME_FUZZ) && active) {
- /* Frame end */
- emit(-1);
- active = 0;
+ 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;
+ uint8_t *BigBuf = BigBuf_get_addr();
+
+ LegicCommonInit();
+
+ DbpString("setting up legic card");
+ uint32_t tag_type = perform_setup_phase_rwd(SESSION_IV);
+ switch_off_tag_rwd();
+ 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(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;
}
-
- if(time >= (20*BIT_TIME_1) && (AT91C_BASE_TC1->TC_SR & AT91C_TC_CLKSTA)) {
- AT91C_BASE_TC1->TC_CCR = AT91C_TC_CLKDIS;
- }
-
-
- old_level = level;
- WDT_HIT();
+ 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()) {
+ 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();
+}
+
projects / proxmark3-svn / blobdiff