-/*
- * LEGIC RF simulation code
- *
- * (c) 2009 Henryk Plötz <henryk@ploetzli.ch>
- */
+//-----------------------------------------------------------------------------
+// (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 "legicrf.h"
-#include <stdint.h>
+#include "util.h"
+#include "string.h"
+#include "legicrf.h"
#include "legic_prng.h"
#include "crc.h"
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)
{
AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_TC1);
timer = AT91C_BASE_TC1;
timer->TC_CCR = AT91C_TC_CLKDIS;
- timer->TC_CMR = TC_CMR_TCCLKS_TIMER_CLOCK3;
+ 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 */
#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
*/
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)
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)
old_level = level;
}
next_bit_at += TAG_TIME_BIT;
-
+
if(edges > 20 && edges < 60) { /* expected are 42 edges */
data ^= the_bit;
}
-
the_bit <<= 1;
}
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;
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);
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);
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;
}
* * 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();
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();
}
projects / proxmark3-svn / blobdiff