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proxmark3/armsrc/iso15693.c
iceman1001 a1529b44ca fix auth and
2020-07-19 20:45:47 +02:00

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//-----------------------------------------------------------------------------
// Jonathan Westhues, split Nov 2006
// Modified by Greg Jones, Jan 2009
// Modified by Adrian Dabrowski "atrox", Mar-Sept 2010,Oct 2011
// Modified by Christian Herrmann "iceman", 2017
// Modified by piwi, Oct 2018
//
// 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.
//-----------------------------------------------------------------------------
// Routines to support ISO 15693. This includes both the reader software and
// the `fake tag' modes.
//-----------------------------------------------------------------------------
// The ISO 15693 describes two transmission modes from reader to tag, and four
// transmission modes from tag to reader. As of Oct 2018 this code supports
// both reader modes and the high speed variant with one subcarrier from card to reader.
// As long as the card fully support ISO 15693 this is no problem, since the
// reader chooses both data rates, but some non-standard tags do not.
// For card simulation, the code supports both high and low speed modes with one subcarrier.
//
// VCD (reader) -> VICC (tag)
// 1 out of 256:
// data rate: 1,66 kbit/s (fc/8192)
// used for long range
// 1 out of 4:
// data rate: 26,48 kbit/s (fc/512)
// used for short range, high speed
//
// VICC (tag) -> VCD (reader)
// Modulation:
// ASK / one subcarrier (423,75 kHz)
// FSK / two subcarriers (423,75 kHz && 484,28 kHz)
// Data Rates / Modes:
// low ASK: 6,62 kbit/s
// low FSK: 6.67 kbit/s
// high ASK: 26,48 kbit/s
// high FSK: 26,69 kbit/s
//-----------------------------------------------------------------------------
// added "1 out of 256" mode (for VCD->PICC) - atrox 20100911
// Random Remarks:
// *) UID is always used "transmission order" (LSB), which is reverse to display order
// TODO / BUGS / ISSUES:
// *) signal decoding is unable to detect collisions.
// *) add anti-collision support for inventory-commands
// *) read security status of a block
// *) sniffing and simulation do not support two subcarrier modes.
// *) remove or refactor code under "deprecated"
// *) document all the functions
#include "iso15693.h"
#include "proxmark3_arm.h"
#include "util.h"
#include "string.h"
#include "iso15693tools.h"
#include "cmd.h"
#include "appmain.h"
#include "dbprint.h"
#include "fpgaloader.h"
#include "commonutil.h"
#include "ticks.h"
#include "BigBuf.h"
#include "crc16.h"
// Delays in SSP_CLK ticks.
// SSP_CLK runs at 13,56MHz / 32 = 423.75kHz when simulating a tag
#define DELAY_READER_TO_ARM 8
#define DELAY_ARM_TO_READER 0
//SSP_CLK runs at 13.56MHz / 4 = 3,39MHz when acting as reader. All values should be multiples of 16
#define DELAY_ARM_TO_TAG 16
#define DELAY_TAG_TO_ARM 32
//SSP_CLK runs at 13.56MHz / 4 = 3,39MHz when sniffing. All values should be multiples of 16
#define DELAY_TAG_TO_ARM_SNIFF 32
#define DELAY_READER_TO_ARM_SNIFF 32
// times in samples @ 212kHz when acting as reader
#define ISO15693_READER_TIMEOUT 330 // 330/212kHz = 1558us, should be even enough for iClass tags responding to ACTALL
#define ISO15693_READER_TIMEOUT_WRITE 4700 // 4700/212kHz = 22ms, nominal 20ms
///////////////////////////////////////////////////////////////////////
// ISO 15693 Part 2 - Air Interface
// This section basically contains transmission and receiving of bits
///////////////////////////////////////////////////////////////////////
// buffers
#define ISO15693_MAX_RESPONSE_LENGTH 36 // allows read single block with the maximum block size of 256bits. Read multiple blocks not supported yet
#define ISO15693_MAX_COMMAND_LENGTH 45 // allows write single block with the maximum block size of 256bits. Write multiple blocks not supported yet
// 32 + 2 crc + 1
#define ISO15_MAX_FRAME 35
#define CMD_ID_RESP 5
#define CMD_READ_RESP 13
#define CMD_INV_RESP 12
//#define Crc(data, len) Crc(CRC_15693, (data), (len))
#define CheckCrc15(data, len) check_crc(CRC_15693, (data), (len))
#define AddCrc15(data, len) compute_crc(CRC_15693, (data), (len), (data)+(len), (data)+(len)+1)
static void BuildIdentifyRequest(uint8_t *cmd);
// ---------------------------
// Signal Processing
// ---------------------------
// prepare data using "1 out of 4" code for later transmission
// resulting data rate is 26.48 kbit/s (fc/512)
// cmd ... data
// n ... length of data
void CodeIso15693AsReader(uint8_t *cmd, int n) {
tosend_reset();
tosend_t *ts = get_tosend();
// SOF for 1of4
ts->buf[++ts->max] = 0x84; //10000100
// data
for (int i = 0; i < n; i++) {
for (int j = 0; j < 8; j += 2) {
uint8_t these = (cmd[i] >> j) & 0x03;
switch(these) {
case 0:
ts->buf[++ts->max] = 0x40; //01000000
break;
case 1:
ts->buf[++ts->max] = 0x10; //00010000
break;
case 2:
ts->buf[++ts->max] = 0x04; //00000100
break;
case 3:
ts->buf[++ts->max] = 0x01; //00000001
break;
}
}
}
// EOF
ts->buf[++ts->max] = 0x20; //0010 + 0000 padding
ts->max++;
}
// Encode EOF only
static void CodeIso15693AsReaderEOF(void) {
tosend_reset();
tosend_t *ts = get_tosend();
ts->buf[++ts->max] = 0x20;
ts->max++;
}
// encode data using "1 out of 256" scheme
// data rate is 1,66 kbit/s (fc/8192)
// is designed for more robust communication over longer distances
static void CodeIso15693AsReader256(uint8_t *cmd, int n) {
tosend_reset();
tosend_t *ts = get_tosend();
// SOF for 1of256
ts->buf[++ts->max] = 0x81; //10000001
// data
for(int i = 0; i < n; i++) {
for (int j = 0; j <= 255; j++) {
if (cmd[i] == j) {
tosend_stuffbit(0);
tosend_stuffbit(1);
} else {
tosend_stuffbit(0);
tosend_stuffbit(0);
}
}
}
// EOF
ts->buf[++ts->max] = 0x20; //0010 + 0000 padding
ts->max++;
}
static const uint8_t encode_4bits[16] = {
0xaa, 0x6a, 0x9a, 0x5a,
0xa6, 0x66, 0x96, 0x56,
0xa9, 0x69, 0x99, 0x59,
0xa5, 0x65, 0x95, 0x55
};
void CodeIso15693AsTag(uint8_t *cmd, size_t len) {
/*
* SOF comprises 3 parts;
* * An unmodulated time of 56.64 us
* * 24 pulses of 423.75 kHz (fc/32)
* * A logic 1, which starts with an unmodulated time of 18.88us
* followed by 8 pulses of 423.75kHz (fc/32)
*
* EOF comprises 3 parts:
* - A logic 0 (which starts with 8 pulses of fc/32 followed by an unmodulated
* time of 18.88us.
* - 24 pulses of fc/32
* - An unmodulated time of 56.64 us
*
* A logic 0 starts with 8 pulses of fc/32
* followed by an unmodulated time of 256/fc (~18,88us).
*
* A logic 0 starts with unmodulated time of 256/fc (~18,88us) followed by
* 8 pulses of fc/32 (also 18.88us)
*
* A bit here becomes 8 pulses of fc/32. Therefore:
* The SOF can be written as 00011101 = 0x1D
* The EOF can be written as 10111000 = 0xb8
* A logic 1 is 01
* A logic 0 is 10
*
* */
tosend_reset();
tosend_t *ts = get_tosend();
// SOF
ts->buf[++ts->max] = 0x1D; // 00011101
// data
for (int i = 0; i < len; i++) {
ts->buf[++ts->max] = encode_4bits[cmd[i] & 0xF];
ts->buf[++ts->max] = encode_4bits[cmd[i] >> 4];
}
// EOF
ts->buf[++ts->max] = 0xB8; // 10111000
ts->max++;
}
// Transmit the command (to the tag) that was placed in cmd[].
void TransmitTo15693Tag(const uint8_t *cmd, int len, uint32_t *start_time) {
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SEND_FULL_MOD);
if (*start_time < DELAY_ARM_TO_TAG) {
*start_time = DELAY_ARM_TO_TAG;
}
*start_time = (*start_time - DELAY_ARM_TO_TAG) & 0xfffffff0;
if (GetCountSspClk() > *start_time) { // we may miss the intended time
*start_time = (GetCountSspClk() + 16) & 0xfffffff0; // next possible time
}
// wait
while (GetCountSspClk() < *start_time) ;
LED_B_ON();
for (int c = 0; c < len; c++) {
volatile uint8_t data = cmd[c];
for (uint8_t i = 0; i < 8; i++) {
uint16_t send_word = (data & 0x80) ? 0xffff : 0x0000;
while (!(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY))) ;
AT91C_BASE_SSC->SSC_THR = send_word;
while (!(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY))) ;
AT91C_BASE_SSC->SSC_THR = send_word;
data <<= 1;
}
WDT_HIT();
}
LED_B_OFF();
*start_time = *start_time + DELAY_ARM_TO_TAG;
}
//-----------------------------------------------------------------------------
// Transmit the tag response (to the reader) that was placed in cmd[].
//-----------------------------------------------------------------------------
void TransmitTo15693Reader(const uint8_t *cmd, size_t len, uint32_t *start_time, uint32_t slot_time, bool slow) {
// don't use the FPGA_HF_SIMULATOR_MODULATE_424K_8BIT minor mode. It would spoil GetCountSspClk()
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_MODULATE_424K);
uint32_t modulation_start_time = *start_time - DELAY_ARM_TO_READER + 3 * 8; // no need to transfer the unmodulated start of SOF
while (GetCountSspClk() > (modulation_start_time & 0xfffffff8) + 3) { // we will miss the intended time
if (slot_time) {
modulation_start_time += slot_time; // use next available slot
} else {
modulation_start_time = (modulation_start_time & 0xfffffff8) + 8; // next possible time
}
}
// wait
while (GetCountSspClk() < (modulation_start_time & 0xfffffff8)) ;
uint8_t shift_delay = modulation_start_time & 0x00000007;
*start_time = modulation_start_time + DELAY_ARM_TO_READER - 3 * 8;
LED_C_ON();
uint8_t bits_to_shift = 0x00;
uint8_t bits_to_send = 0x00;
for (size_t c = 0; c < len; c++) {
for (int i = (c == 0 ? 4 : 7); i >= 0; i--) {
uint8_t cmd_bits = ((cmd[c] >> i) & 0x01) ? 0xff : 0x00;
for (int j = 0; j < (slow ? 4 : 1); ) {
if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
bits_to_send = bits_to_shift << (8 - shift_delay) | cmd_bits >> shift_delay;
AT91C_BASE_SSC->SSC_THR = bits_to_send;
bits_to_shift = cmd_bits;
j++;
}
}
}
WDT_HIT();
}
// send the remaining bits, padded with 0:
bits_to_send = bits_to_shift << (8 - shift_delay);
for ( ; ; ) {
if (AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXRDY) {
AT91C_BASE_SSC->SSC_THR = bits_to_send;
break;
}
}
LED_C_OFF();
}
//=============================================================================
// An ISO 15693 decoder for tag responses (one subcarrier only).
// Uses cross correlation to identify each bit and EOF.
// This function is called 8 times per bit (every 2 subcarrier cycles).
// Subcarrier frequency fs is 424kHz, 1/fs = 2,36us,
// i.e. function is called every 4,72us
// 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
//=============================================================================
#define NOISE_THRESHOLD 80 // don't try to correlate noise
#define MAX_PREVIOUS_AMPLITUDE (-1 - NOISE_THRESHOLD)
typedef struct DecodeTag {
enum {
STATE_TAG_SOF_LOW,
STATE_TAG_SOF_RISING_EDGE,
STATE_TAG_SOF_HIGH,
STATE_TAG_SOF_HIGH_END,
STATE_TAG_RECEIVING_DATA,
STATE_TAG_EOF,
STATE_TAG_EOF_TAIL
} state;
int bitCount;
int posCount;
enum {
LOGIC0,
LOGIC1,
SOF_PART1,
SOF_PART2
} lastBit;
uint16_t shiftReg;
uint16_t max_len;
uint8_t *output;
int len;
int sum1;
int sum2;
int threshold_sof;
int threshold_half;
uint16_t previous_amplitude;
} DecodeTag_t;
//-----------------------------------------------------------------------------
// DEMODULATE tag answer
//-----------------------------------------------------------------------------
static RAMFUNC int Handle15693SamplesFromTag(uint16_t amplitude, DecodeTag_t *DecodeTag) {
switch (DecodeTag->state) {
case STATE_TAG_SOF_LOW: {
// waiting for a rising edge
if (amplitude > NOISE_THRESHOLD + DecodeTag->previous_amplitude) {
if (DecodeTag->posCount > 10) {
DecodeTag->threshold_sof = amplitude - DecodeTag->previous_amplitude; // to be divided by 2
DecodeTag->threshold_half = 0;
DecodeTag->state = STATE_TAG_SOF_RISING_EDGE;
} else {
DecodeTag->posCount = 0;
}
} else {
DecodeTag->posCount++;
DecodeTag->previous_amplitude = amplitude;
}
break;
}
case STATE_TAG_SOF_RISING_EDGE: {
if (amplitude > DecodeTag->threshold_sof + DecodeTag->previous_amplitude) { // edge still rising
if (amplitude > DecodeTag->threshold_sof + DecodeTag->threshold_sof) { // steeper edge, take this as time reference
DecodeTag->posCount = 1;
} else {
DecodeTag->posCount = 2;
}
DecodeTag->threshold_sof = (amplitude - DecodeTag->previous_amplitude) / 2;
} else {
DecodeTag->posCount = 2;
DecodeTag->threshold_sof = DecodeTag->threshold_sof / 2;
}
// DecodeTag->posCount = 2;
DecodeTag->state = STATE_TAG_SOF_HIGH;
break;
}
case STATE_TAG_SOF_HIGH: {
// waiting for 10 times high. Take average over the last 8
if (amplitude > DecodeTag->threshold_sof) {
DecodeTag->posCount++;
if (DecodeTag->posCount > 2) {
DecodeTag->threshold_half += amplitude; // keep track of average high value
}
if (DecodeTag->posCount == 10) {
DecodeTag->threshold_half >>= 2; // (4 times 1/2 average)
DecodeTag->state = STATE_TAG_SOF_HIGH_END;
}
} else { // high phase was too short
DecodeTag->posCount = 1;
DecodeTag->previous_amplitude = amplitude;
DecodeTag->state = STATE_TAG_SOF_LOW;
}
break;
}
case STATE_TAG_SOF_HIGH_END: {
// check for falling edge
if (DecodeTag->posCount == 13 && amplitude < DecodeTag->threshold_sof) {
DecodeTag->lastBit = SOF_PART1; // detected 1st part of SOF (12 samples low and 12 samples high)
DecodeTag->shiftReg = 0;
DecodeTag->bitCount = 0;
DecodeTag->len = 0;
DecodeTag->sum1 = amplitude;
DecodeTag->sum2 = 0;
DecodeTag->posCount = 2;
DecodeTag->state = STATE_TAG_RECEIVING_DATA;
// FpgaDisableTracing(); // DEBUGGING
// Dbprintf("amplitude = %d, threshold_sof = %d, threshold_half/4 = %d, previous_amplitude = %d",
// amplitude,
// DecodeTag->threshold_sof,
// DecodeTag->threshold_half/4,
// DecodeTag->previous_amplitude); // DEBUGGING
LED_C_ON();
} else {
DecodeTag->posCount++;
if (DecodeTag->posCount > 13) { // high phase too long
DecodeTag->posCount = 0;
DecodeTag->previous_amplitude = amplitude;
DecodeTag->state = STATE_TAG_SOF_LOW;
LED_C_OFF();
}
}
break;
}
case STATE_TAG_RECEIVING_DATA: {
// FpgaDisableTracing(); // DEBUGGING
// Dbprintf("amplitude = %d, threshold_sof = %d, threshold_half/4 = %d, previous_amplitude = %d",
// amplitude,
// DecodeTag->threshold_sof,
// DecodeTag->threshold_half/4,
// DecodeTag->previous_amplitude); // DEBUGGING
if (DecodeTag->posCount == 1) {
DecodeTag->sum1 = 0;
DecodeTag->sum2 = 0;
}
if (DecodeTag->posCount <= 4) {
DecodeTag->sum1 += amplitude;
} else {
DecodeTag->sum2 += amplitude;
}
if (DecodeTag->posCount == 8) {
if (DecodeTag->sum1 > DecodeTag->threshold_half && DecodeTag->sum2 > DecodeTag->threshold_half) { // modulation in both halves
if (DecodeTag->lastBit == LOGIC0) { // this was already part of EOF
DecodeTag->state = STATE_TAG_EOF;
} else {
DecodeTag->posCount = 0;
DecodeTag->previous_amplitude = amplitude;
DecodeTag->state = STATE_TAG_SOF_LOW;
LED_C_OFF();
}
} else if (DecodeTag->sum1 < DecodeTag->threshold_half && DecodeTag->sum2 > DecodeTag->threshold_half) { // modulation in second half
// logic 1
if (DecodeTag->lastBit == SOF_PART1) { // still part of SOF
DecodeTag->lastBit = SOF_PART2; // SOF completed
} else {
DecodeTag->lastBit = LOGIC1;
DecodeTag->shiftReg >>= 1;
DecodeTag->shiftReg |= 0x80;
DecodeTag->bitCount++;
if (DecodeTag->bitCount == 8) {
DecodeTag->output[DecodeTag->len] = DecodeTag->shiftReg;
DecodeTag->len++;
// if (DecodeTag->shiftReg == 0x12 && DecodeTag->len == 1) FpgaDisableTracing(); // DEBUGGING
if (DecodeTag->len > DecodeTag->max_len) {
// buffer overflow, give up
LED_C_OFF();
return true;
}
DecodeTag->bitCount = 0;
DecodeTag->shiftReg = 0;
}
}
} else if (DecodeTag->sum1 > DecodeTag->threshold_half && DecodeTag->sum2 < DecodeTag->threshold_half) { // modulation in first half
// logic 0
if (DecodeTag->lastBit == SOF_PART1) { // incomplete SOF
DecodeTag->posCount = 0;
DecodeTag->previous_amplitude = amplitude;
DecodeTag->state = STATE_TAG_SOF_LOW;
LED_C_OFF();
} else {
DecodeTag->lastBit = LOGIC0;
DecodeTag->shiftReg >>= 1;
DecodeTag->bitCount++;
if (DecodeTag->bitCount == 8) {
DecodeTag->output[DecodeTag->len] = DecodeTag->shiftReg;
DecodeTag->len++;
// if (DecodeTag->shiftReg == 0x12 && DecodeTag->len == 1) FpgaDisableTracing(); // DEBUGGING
if (DecodeTag->len > DecodeTag->max_len) {
// buffer overflow, give up
DecodeTag->posCount = 0;
DecodeTag->previous_amplitude = amplitude;
DecodeTag->state = STATE_TAG_SOF_LOW;
LED_C_OFF();
}
DecodeTag->bitCount = 0;
DecodeTag->shiftReg = 0;
}
}
} else { // no modulation
if (DecodeTag->lastBit == SOF_PART2) { // only SOF (this is OK for iClass)
LED_C_OFF();
return true;
} else {
DecodeTag->posCount = 0;
DecodeTag->state = STATE_TAG_SOF_LOW;
LED_C_OFF();
}
}
DecodeTag->posCount = 0;
}
DecodeTag->posCount++;
break;
}
case STATE_TAG_EOF: {
if (DecodeTag->posCount == 1) {
DecodeTag->sum1 = 0;
DecodeTag->sum2 = 0;
}
if (DecodeTag->posCount <= 4) {
DecodeTag->sum1 += amplitude;
} else {
DecodeTag->sum2 += amplitude;
}
if (DecodeTag->posCount == 8) {
if (DecodeTag->sum1 > DecodeTag->threshold_half && DecodeTag->sum2 < DecodeTag->threshold_half) { // modulation in first half
DecodeTag->posCount = 0;
DecodeTag->state = STATE_TAG_EOF_TAIL;
} else {
DecodeTag->posCount = 0;
DecodeTag->previous_amplitude = amplitude;
DecodeTag->state = STATE_TAG_SOF_LOW;
LED_C_OFF();
}
}
DecodeTag->posCount++;
break;
}
case STATE_TAG_EOF_TAIL: {
if (DecodeTag->posCount == 1) {
DecodeTag->sum1 = 0;
DecodeTag->sum2 = 0;
}
if (DecodeTag->posCount <= 4) {
DecodeTag->sum1 += amplitude;
} else {
DecodeTag->sum2 += amplitude;
}
if (DecodeTag->posCount == 8) {
if (DecodeTag->sum1 < DecodeTag->threshold_half && DecodeTag->sum2 < DecodeTag->threshold_half) { // no modulation in both halves
LED_C_OFF();
return true;
} else {
DecodeTag->posCount = 0;
DecodeTag->previous_amplitude = amplitude;
DecodeTag->state = STATE_TAG_SOF_LOW;
LED_C_OFF();
}
}
DecodeTag->posCount++;
break;
}
}
return false;
}
static void DecodeTagInit(DecodeTag_t *DecodeTag, uint8_t *data, uint16_t max_len) {
DecodeTag->previous_amplitude = MAX_PREVIOUS_AMPLITUDE;
DecodeTag->posCount = 0;
DecodeTag->state = STATE_TAG_SOF_LOW;
DecodeTag->output = data;
DecodeTag->max_len = max_len;
}
static void DecodeTagReset(DecodeTag_t *DecodeTag) {
DecodeTag->posCount = 0;
DecodeTag->state = STATE_TAG_SOF_LOW;
DecodeTag->previous_amplitude = MAX_PREVIOUS_AMPLITUDE;
}
/*
* Receive and decode the tag response, also log to tracebuffer
*/
int GetIso15693AnswerFromTag(uint8_t* response, uint16_t max_len, uint16_t timeout, uint32_t *eof_time) {
int samples = 0, ret = 0;
// the Decoder data structure
DecodeTag_t DecodeTag = { 0 };
DecodeTagInit(&DecodeTag, response, max_len);
// wait for last transfer to complete
while (!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXEMPTY));
// And put the FPGA in the appropriate mode
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_SUBCARRIER_424_KHZ | FPGA_HF_READER_MODE_RECEIVE_AMPLITUDE);
// Setup and start DMA.
FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER);
// The DMA buffer, used to stream samples from the FPGA
dmabuf16_t *dma = get_dma16();
FpgaSetupSscDma((uint8_t*) dma->buf, DMA_BUFFER_SIZE);
uint32_t dma_start_time = 0;
uint16_t *upTo = dma->buf;
for(;;) {
uint16_t behindBy = ((uint16_t*)AT91C_BASE_PDC_SSC->PDC_RPR - upTo) & (DMA_BUFFER_SIZE - 1);
if (behindBy == 0)
continue;
samples++;
if (samples == 1) {
// DMA has transferred the very first data
dma_start_time = GetCountSspClk() & 0xfffffff0;
}
volatile uint16_t tagdata = *upTo++;
if (upTo >= dma->buf + DMA_BUFFER_SIZE) { // we have read all of the DMA buffer content.
upTo = dma->buf; // start reading the circular buffer from the beginning
if (behindBy > (9 * DMA_BUFFER_SIZE / 10)) {
Dbprintf("About to blow circular buffer - aborted! behindBy=%d", behindBy);
ret = -1;
break;
}
}
if (AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_ENDRX)) { // DMA Counter Register had reached 0, already rotated.
AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dma->buf; // refresh the DMA Next Buffer and
AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE; // DMA Next Counter registers
}
if (Handle15693SamplesFromTag(tagdata, &DecodeTag)) {
*eof_time = dma_start_time + (samples * 16) - DELAY_TAG_TO_ARM; // end of EOF
if (DecodeTag.lastBit == SOF_PART2) {
*eof_time -= (8 * 16); // needed 8 additional samples to confirm single SOF (iCLASS)
}
if (DecodeTag.len > DecodeTag.max_len) {
ret = -2; // buffer overflow
}
break;
}
if (samples > timeout && DecodeTag.state < STATE_TAG_RECEIVING_DATA) {
ret = -3; // timeout
break;
}
}
FpgaDisableSscDma();
uint32_t sof_time = *eof_time
- (DecodeTag.len * 8 * 8 * 16) // time for byte transfers
- (32 * 16) // time for SOF transfer
- (DecodeTag.lastBit != SOF_PART2 ? (32 * 16) : 0); // time for EOF transfer
if (DBGLEVEL >= DBG_EXTENDED) {
Dbprintf("samples = %d, ret = %d, Decoder: state = %d, lastBit = %d, len = %d, bitCount = %d, posCount = %d, maxlen = %u",
samples,
ret,
DecodeTag.state,
DecodeTag.lastBit,
DecodeTag.len,
DecodeTag.bitCount,
DecodeTag.posCount,
DecodeTag.max_len
);
Dbprintf("timing: sof_time = %d, eof_time = %d", (sof_time * 4), (*eof_time * 4));
}
if (ret == -1) {
return ret;
}
LogTrace(DecodeTag.output, DecodeTag.len, (sof_time * 4), (*eof_time * 4), NULL, false);
return DecodeTag.len;
}
//=============================================================================
// An ISO15693 decoder for reader commands.
//
// This function is called 4 times per bit (every 2 subcarrier cycles).
// Subcarrier frequency fs is 848kHz, 1/fs = 1,18us, i.e. function is called every 2,36us
// LED handling:
// LED B -> ON once we have received the SOF and are expecting the rest.
// LED B -> 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
//=============================================================================
typedef struct DecodeReader {
enum {
STATE_READER_UNSYNCD,
STATE_READER_AWAIT_1ST_FALLING_EDGE_OF_SOF,
STATE_READER_AWAIT_1ST_RISING_EDGE_OF_SOF,
STATE_READER_AWAIT_2ND_FALLING_EDGE_OF_SOF,
STATE_READER_AWAIT_2ND_RISING_EDGE_OF_SOF,
STATE_READER_AWAIT_END_OF_SOF_1_OUT_OF_4,
STATE_READER_RECEIVE_DATA_1_OUT_OF_4,
STATE_READER_RECEIVE_DATA_1_OUT_OF_256,
STATE_READER_RECEIVE_JAMMING
} state;
enum {
CODING_1_OUT_OF_4,
CODING_1_OUT_OF_256
} Coding;
uint8_t shiftReg;
uint8_t bitCount;
int byteCount;
int byteCountMax;
int posCount;
int sum1, sum2;
uint8_t *output;
uint8_t jam_search_len;
uint8_t *jam_search_string;
} DecodeReader_t;
static void DecodeReaderInit(DecodeReader_t* DecodeReader, uint8_t *data, uint16_t max_len, uint8_t jam_search_len, uint8_t *jam_search_string) {
DecodeReader->output = data;
DecodeReader->byteCountMax = max_len;
DecodeReader->state = STATE_READER_UNSYNCD;
DecodeReader->byteCount = 0;
DecodeReader->bitCount = 0;
DecodeReader->posCount = 1;
DecodeReader->shiftReg = 0;
DecodeReader->jam_search_len = jam_search_len;
DecodeReader->jam_search_string = jam_search_string;
}
static void DecodeReaderReset(DecodeReader_t* DecodeReader) {
DecodeReader->state = STATE_READER_UNSYNCD;
}
static RAMFUNC int Handle15693SampleFromReader(bool bit, DecodeReader_t *DecodeReader) {
switch (DecodeReader->state) {
case STATE_READER_UNSYNCD:
// wait for unmodulated carrier
if (bit) {
DecodeReader->state = STATE_READER_AWAIT_1ST_FALLING_EDGE_OF_SOF;
}
break;
case STATE_READER_AWAIT_1ST_FALLING_EDGE_OF_SOF:
if (!bit) {
// we went low, so this could be the beginning of a SOF
DecodeReader->posCount = 1;
DecodeReader->state = STATE_READER_AWAIT_1ST_RISING_EDGE_OF_SOF;
}
break;
case STATE_READER_AWAIT_1ST_RISING_EDGE_OF_SOF:
DecodeReader->posCount++;
if (bit) { // detected rising edge
if (DecodeReader->posCount < 4) { // rising edge too early (nominally expected at 5)
DecodeReader->state = STATE_READER_AWAIT_1ST_FALLING_EDGE_OF_SOF;
} else { // SOF
DecodeReader->state = STATE_READER_AWAIT_2ND_FALLING_EDGE_OF_SOF;
}
} else {
if (DecodeReader->posCount > 5) { // stayed low for too long
DecodeReaderReset(DecodeReader);
} else {
// do nothing, keep waiting
}
}
break;
case STATE_READER_AWAIT_2ND_FALLING_EDGE_OF_SOF:
DecodeReader->posCount++;
if (!bit) { // detected a falling edge
if (DecodeReader->posCount < 20) { // falling edge too early (nominally expected at 21 earliest)
DecodeReaderReset(DecodeReader);
} else if (DecodeReader->posCount < 23) { // SOF for 1 out of 4 coding
DecodeReader->Coding = CODING_1_OUT_OF_4;
DecodeReader->state = STATE_READER_AWAIT_2ND_RISING_EDGE_OF_SOF;
} else if (DecodeReader->posCount < 28) { // falling edge too early (nominally expected at 29 latest)
DecodeReaderReset(DecodeReader);
} else { // SOF for 1 out of 256 coding
DecodeReader->Coding = CODING_1_OUT_OF_256;
DecodeReader->state = STATE_READER_AWAIT_2ND_RISING_EDGE_OF_SOF;
}
} else {
if (DecodeReader->posCount > 29) { // stayed high for too long
DecodeReader->state = STATE_READER_AWAIT_1ST_FALLING_EDGE_OF_SOF;
} else {
// do nothing, keep waiting
}
}
break;
case STATE_READER_AWAIT_2ND_RISING_EDGE_OF_SOF:
DecodeReader->posCount++;
if (bit) { // detected rising edge
if (DecodeReader->Coding == CODING_1_OUT_OF_256) {
if (DecodeReader->posCount < 32) { // rising edge too early (nominally expected at 33)
DecodeReader->state = STATE_READER_AWAIT_1ST_FALLING_EDGE_OF_SOF;
} else {
DecodeReader->posCount = 1;
DecodeReader->bitCount = 0;
DecodeReader->byteCount = 0;
DecodeReader->sum1 = 1;
DecodeReader->state = STATE_READER_RECEIVE_DATA_1_OUT_OF_256;
LED_B_ON();
}
} else { // CODING_1_OUT_OF_4
if (DecodeReader->posCount < 24) { // rising edge too early (nominally expected at 25)
DecodeReader->state = STATE_READER_AWAIT_1ST_FALLING_EDGE_OF_SOF;
} else {
DecodeReader->posCount = 1;
DecodeReader->state = STATE_READER_AWAIT_END_OF_SOF_1_OUT_OF_4;
}
}
} else {
if (DecodeReader->Coding == CODING_1_OUT_OF_256) {
if (DecodeReader->posCount > 34) { // signal stayed low for too long
DecodeReaderReset(DecodeReader);
} else {
// do nothing, keep waiting
}
} else { // CODING_1_OUT_OF_4
if (DecodeReader->posCount > 26) { // signal stayed low for too long
DecodeReaderReset(DecodeReader);
} else {
// do nothing, keep waiting
}
}
}
break;
case STATE_READER_AWAIT_END_OF_SOF_1_OUT_OF_4:
DecodeReader->posCount++;
if (bit) {
if (DecodeReader->posCount == 9) {
DecodeReader->posCount = 1;
DecodeReader->bitCount = 0;
DecodeReader->byteCount = 0;
DecodeReader->sum1 = 1;
DecodeReader->state = STATE_READER_RECEIVE_DATA_1_OUT_OF_4;
LED_B_ON();
} else {
// do nothing, keep waiting
}
} else { // unexpected falling edge
DecodeReaderReset(DecodeReader);
}
break;
case STATE_READER_RECEIVE_DATA_1_OUT_OF_4:
DecodeReader->posCount++;
if (DecodeReader->posCount == 1) {
DecodeReader->sum1 = bit ? 1 : 0;
} else if (DecodeReader->posCount <= 4) {
if (bit) DecodeReader->sum1++;
} else if (DecodeReader->posCount == 5) {
DecodeReader->sum2 = bit ? 1 : 0;
} else {
if (bit) DecodeReader->sum2++;
}
if (DecodeReader->posCount == 8) {
DecodeReader->posCount = 0;
if (DecodeReader->sum1 <= 1 && DecodeReader->sum2 >= 3) { // EOF
LED_B_OFF(); // Finished receiving
DecodeReaderReset(DecodeReader);
if (DecodeReader->byteCount != 0) {
return true;
}
} else if (DecodeReader->sum1 >= 3 && DecodeReader->sum2 <= 1) { // detected a 2bit position
DecodeReader->shiftReg >>= 2;
DecodeReader->shiftReg |= (DecodeReader->bitCount << 6);
}
if (DecodeReader->bitCount == 15) { // we have a full byte
DecodeReader->output[DecodeReader->byteCount++] = DecodeReader->shiftReg;
if (DecodeReader->byteCount > DecodeReader->byteCountMax) {
// buffer overflow, give up
LED_B_OFF();
DecodeReaderReset(DecodeReader);
}
DecodeReader->bitCount = 0;
DecodeReader->shiftReg = 0;
if (DecodeReader->byteCount == DecodeReader->jam_search_len) {
if (!memcmp(DecodeReader->output, DecodeReader->jam_search_string, DecodeReader->jam_search_len)) {
LED_D_ON();
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SEND_JAM);
DecodeReader->state = STATE_READER_RECEIVE_JAMMING;
}
}
} else {
DecodeReader->bitCount++;
}
}
break;
case STATE_READER_RECEIVE_DATA_1_OUT_OF_256:
DecodeReader->posCount++;
if (DecodeReader->posCount == 1) {
DecodeReader->sum1 = bit ? 1 : 0;
} else if (DecodeReader->posCount <= 4) {
if (bit) DecodeReader->sum1++;
} else if (DecodeReader->posCount == 5) {
DecodeReader->sum2 = bit ? 1 : 0;
} else if (bit) {
DecodeReader->sum2++;
}
if (DecodeReader->posCount == 8) {
DecodeReader->posCount = 0;
if (DecodeReader->sum1 <= 1 && DecodeReader->sum2 >= 3) { // EOF
LED_B_OFF(); // Finished receiving
DecodeReaderReset(DecodeReader);
if (DecodeReader->byteCount != 0) {
return true;
}
} else if (DecodeReader->sum1 >= 3 && DecodeReader->sum2 <= 1) { // detected the bit position
DecodeReader->shiftReg = DecodeReader->bitCount;
}
if (DecodeReader->bitCount == 255) { // we have a full byte
DecodeReader->output[DecodeReader->byteCount++] = DecodeReader->shiftReg;
if (DecodeReader->byteCount > DecodeReader->byteCountMax) {
// buffer overflow, give up
LED_B_OFF();
DecodeReaderReset(DecodeReader);
}
if (DecodeReader->byteCount == DecodeReader->jam_search_len) {
if (!memcmp(DecodeReader->output, DecodeReader->jam_search_string, DecodeReader->jam_search_len)) {
LED_D_ON();
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SEND_JAM);
DecodeReader->state = STATE_READER_RECEIVE_JAMMING;
}
}
}
DecodeReader->bitCount++;
}
break;
case STATE_READER_RECEIVE_JAMMING:
DecodeReader->posCount++;
if (DecodeReader->Coding == CODING_1_OUT_OF_4) {
if (DecodeReader->posCount == 7 * 16) { // 7 bits jammed
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SNIFF_AMPLITUDE); // stop jamming
// FpgaDisableTracing();
LED_D_OFF();
} else if (DecodeReader->posCount == 8 * 16) {
DecodeReader->posCount = 0;
DecodeReader->output[DecodeReader->byteCount++] = 0x00;
DecodeReader->state = STATE_READER_RECEIVE_DATA_1_OUT_OF_4;
}
} else {
if (DecodeReader->posCount == 7 * 256) { // 7 bits jammend
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SNIFF_AMPLITUDE); // stop jamming
LED_D_OFF();
} else if (DecodeReader->posCount == 8 * 256) {
DecodeReader->posCount = 0;
DecodeReader->output[DecodeReader->byteCount++] = 0x00;
DecodeReader->state = STATE_READER_RECEIVE_DATA_1_OUT_OF_256;
}
}
break;
default:
LED_B_OFF();
DecodeReaderReset(DecodeReader);
break;
}
return false;
}
//-----------------------------------------------------------------------------
// Receive a command (from the reader to us, where we are the simulated tag),
// and store it in the given buffer, up to the given maximum length. Keeps
// spinning, waiting for a well-framed command, until either we get one
// (returns len) or someone presses the pushbutton on the board (returns -1).
//
// Assume that we're called with the SSC (to the FPGA) and ADC path set
// correctly.
//-----------------------------------------------------------------------------
int GetIso15693CommandFromReader(uint8_t *received, size_t max_len, uint32_t *eof_time) {
int samples = 0;
bool gotFrame = false;
// the decoder data structure
DecodeReader_t DecodeReader = {0};
DecodeReaderInit(&DecodeReader, received, max_len, 0, NULL);
// wait for last transfer to complete
while (!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXEMPTY));
LED_D_OFF();
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_NO_MODULATION);
// clear receive register and wait for next transfer
uint32_t temp = AT91C_BASE_SSC->SSC_RHR;
(void) temp;
while (!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY)) ;
uint32_t dma_start_time = GetCountSspClk() & 0xfffffff8;
// Setup and start DMA.
dmabuf8_t *dma = get_dma8();
FpgaSetupSscDma(dma->buf, DMA_BUFFER_SIZE);
uint8_t *upTo = dma->buf;
for (;;) {
uint16_t behindBy = ((uint8_t*)AT91C_BASE_PDC_SSC->PDC_RPR - upTo) & (DMA_BUFFER_SIZE - 1);
if (behindBy == 0) continue;
volatile uint8_t b = *upTo++;
if (upTo >= dma->buf + DMA_BUFFER_SIZE) { // we have read all of the DMA buffer content.
upTo = dma->buf; // start reading the circular buffer from the beginning
if (behindBy > (9 * DMA_BUFFER_SIZE / 10)) {
Dbprintf("About to blow circular buffer - aborted! behindBy %d", behindBy);
break;
}
}
if (AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_ENDRX)) { // DMA Counter Register had reached 0, already rotated.
AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dma->buf; // refresh the DMA Next Buffer and
AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE; // DMA Next Counter registers
}
for (int i = 7; i >= 0; i--) {
if (Handle15693SampleFromReader((b >> i) & 0x01, &DecodeReader)) {
*eof_time = dma_start_time + samples - DELAY_READER_TO_ARM; // end of EOF
gotFrame = true;
break;
}
samples++;
}
if (BUTTON_PRESS()) {
DecodeReader.byteCount = -1;
break;
}
WDT_HIT();
if (gotFrame) {
break;
}
}
FpgaDisableSscDma();
if (DBGLEVEL >= DBG_EXTENDED) {
Dbprintf("samples = %d, gotFrame = %d, Decoder: state = %d, len = %d, bitCount = %d, posCount = %d",
samples, gotFrame, DecodeReader.state, DecodeReader.byteCount,
DecodeReader.bitCount, DecodeReader.posCount);
}
if (DecodeReader.byteCount > 0) {
uint32_t sof_time = *eof_time
- DecodeReader.byteCount * (DecodeReader.Coding == CODING_1_OUT_OF_4 ? 128 : 2048) // time for byte transfers
- 32 // time for SOF transfer
- 16; // time for EOF transfer
LogTrace(DecodeReader.output, DecodeReader.byteCount, (sof_time * 32), (*eof_time * 32), NULL, true);
}
return DecodeReader.byteCount;
}
//-----------------------------------------------------------------------------
// Start to read an ISO 15693 tag. We send an identify request, then wait
// for the response. The response is not demodulated, just left in the buffer
// so that it can be downloaded to a PC and processed there.
//-----------------------------------------------------------------------------
void AcquireRawAdcSamplesIso15693(void) {
LED_A_ON();
uint8_t *dest = BigBuf_malloc(4000);
FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER);
LED_D_ON();
FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER);
SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
uint8_t cmd[5];
BuildIdentifyRequest(cmd);
CodeIso15693AsReader(cmd, sizeof(cmd));
// Give the tags time to energize
SpinDelay(100);
// Now send the command
tosend_t *ts = get_tosend();
uint32_t start_time = 0;
TransmitTo15693Tag(ts->buf, ts->max, &start_time);
// wait for last transfer to complete
while (!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_TXEMPTY)) ;
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_SUBCARRIER_424_KHZ | FPGA_HF_READER_MODE_RECEIVE_AMPLITUDE);
for(int c = 0; c < 4000; ) {
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
uint16_t r = AT91C_BASE_SSC->SSC_RHR;
dest[c++] = r >> 5;
}
}
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
LEDsoff();
}
void SniffIso15693(uint8_t jam_search_len, uint8_t *jam_search_string) {
LED_A_ON();
FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
clear_trace();
set_tracing(true);
// Count of samples received so far, so that we can include timing
int samples = 0;
DecodeTag_t DecodeTag = {0};
uint8_t response[ISO15693_MAX_RESPONSE_LENGTH] = {0};
DecodeTagInit(&DecodeTag, response, sizeof(response));
DecodeReader_t DecodeReader = {0};
uint8_t cmd[ISO15693_MAX_COMMAND_LENGTH] = {0};
DecodeReaderInit(&DecodeReader, cmd, sizeof(cmd), jam_search_len, jam_search_string);
// Print some debug information about the buffer sizes
if (DBGLEVEL >= DBG_EXTENDED) {
Dbprintf("Sniffing buffers initialized:");
Dbprintf(" Trace: %i bytes", BigBuf_max_traceLen());
Dbprintf(" Reader -> tag: %i bytes", ISO15693_MAX_COMMAND_LENGTH);
Dbprintf(" Tag -> Reader: %i bytes", ISO15693_MAX_RESPONSE_LENGTH);
Dbprintf(" DMA: %i bytes", DMA_BUFFER_SIZE * sizeof(uint16_t));
}
Dbprintf("Sniff started. Press PM3 Button to stop.");
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER | FPGA_HF_READER_MODE_SNIFF_AMPLITUDE);
LED_D_OFF();
SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER);
StartCountSspClk();
// The DMA buffer, used to stream samples from the FPGA
dmabuf16_t *dma = get_dma16();
FpgaSetupSscDma((uint8_t*)dma->buf, DMA_BUFFER_SIZE);
uint16_t *upTo = dma->buf;
bool tag_is_active = false;
bool reader_is_active = false;
bool expect_tag_answer = false;
uint32_t dma_start_time = 0;
uint16_t max_behindBy = 0;
// And now we loop, receiving samples.
for(;;) {
uint16_t behindBy = ((uint16_t*)AT91C_BASE_PDC_SSC->PDC_RPR - upTo) & (DMA_BUFFER_SIZE - 1);
if (behindBy > max_behindBy) {
max_behindBy = behindBy;
}
if (behindBy == 0) continue;
samples++;
if (samples == 1) {
// DMA has transferred the very first data
dma_start_time = GetCountSspClk() & 0xfffffff0;
}
uint16_t sniffdata = *upTo++;
if (upTo >= dma->buf + DMA_BUFFER_SIZE) { // we have read all of the DMA buffer content.
upTo = dma->buf; // start reading the circular buffer from the beginning
if (behindBy > (9 * DMA_BUFFER_SIZE / 10)) {
Dbprintf("About to blow circular buffer - aborted! behindBy=%d, samples=%d", behindBy, samples);
break;
}
if (AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_ENDRX)) { // DMA Counter Register had reached 0, already rotated.
AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dma->buf; // refresh the DMA Next Buffer and
AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE; // DMA Next Counter registers
WDT_HIT();
if (BUTTON_PRESS()) {
DbpString("Sniff stopped.");
break;
}
}
}
// no need to try decoding reader data if the tag is sending
if (tag_is_active == false) {
if (Handle15693SampleFromReader(sniffdata & 0x02, &DecodeReader)) {
uint32_t eof_time = dma_start_time + (samples * 16) + 8 - DELAY_READER_TO_ARM_SNIFF; // end of EOF
if (DecodeReader.byteCount > 0) {
uint32_t sof_time = eof_time
- DecodeReader.byteCount * (DecodeReader.Coding == CODING_1_OUT_OF_4 ? 128 * 16 : 2048 * 16) // time for byte transfers
- 32 * 16 // time for SOF transfer
- 16 * 16; // time for EOF transfer
LogTrace(DecodeReader.output, DecodeReader.byteCount, (sof_time * 4), (eof_time * 4), NULL, true);
}
// And ready to receive another command.
DecodeReaderReset(&DecodeReader);
// And also reset the demod code, which might have been
// false-triggered by the commands from the reader.
DecodeTagReset(&DecodeTag);
reader_is_active = false;
expect_tag_answer = true;
} else if (Handle15693SampleFromReader(sniffdata & 0x01, &DecodeReader)) {
uint32_t eof_time = dma_start_time + (samples * 16) + 16 - DELAY_READER_TO_ARM_SNIFF; // end of EOF
if (DecodeReader.byteCount > 0) {
uint32_t sof_time = eof_time
- DecodeReader.byteCount * (DecodeReader.Coding == CODING_1_OUT_OF_4 ? 128 * 16 : 2048 * 16) // time for byte transfers
- 32 * 16 // time for SOF transfer
- 16 * 16; // time for EOF transfer
LogTrace(DecodeReader.output, DecodeReader.byteCount, (sof_time * 4), (eof_time * 4), NULL, true);
}
// And ready to receive another command
DecodeReaderReset(&DecodeReader);
// And also reset the demod code, which might have been
// false-triggered by the commands from the reader.
DecodeTagReset(&DecodeTag);
reader_is_active = false;
expect_tag_answer = true;
} else {
reader_is_active = (DecodeReader.state >= STATE_READER_RECEIVE_DATA_1_OUT_OF_4);
}
}
if (!reader_is_active && expect_tag_answer) { // no need to try decoding tag data if the reader is currently sending or no answer expected yet
if (Handle15693SamplesFromTag(sniffdata >> 2, &DecodeTag)) {
uint32_t eof_time = dma_start_time + (samples * 16) - DELAY_TAG_TO_ARM_SNIFF; // end of EOF
if (DecodeTag.lastBit == SOF_PART2) {
eof_time -= (8 * 16); // needed 8 additional samples to confirm single SOF (iCLASS)
}
uint32_t sof_time = eof_time
- DecodeTag.len * 8 * 8 * 16 // time for byte transfers
- (32 * 16) // time for SOF transfer
- (DecodeTag.lastBit != SOF_PART2 ? (32 * 16) : 0); // time for EOF transfer
LogTrace(DecodeTag.output, DecodeTag.len, (sof_time * 4), (eof_time * 4), NULL, false);
// And ready to receive another response.
DecodeTagReset(&DecodeTag);
DecodeReaderReset(&DecodeReader);
expect_tag_answer = false;
tag_is_active = false;
} else {
tag_is_active = (DecodeTag.state >= STATE_TAG_RECEIVING_DATA);
}
}
}
switch_off();
DbpString("Sniff statistics:");
Dbprintf(" ExpectTagAnswer: %d, TagIsActive: %d, ReaderIsActive: %d", expect_tag_answer, tag_is_active, reader_is_active);
Dbprintf(" DecodeTag State: %d", DecodeTag.state);
Dbprintf(" DecodeTag byteCnt: %d", DecodeTag.len);
Dbprintf(" DecodeTag posCount: %d", DecodeTag.posCount);
Dbprintf(" DecodeReader State: %d", DecodeReader.state);
Dbprintf(" DecodeReader byteCnt: %d", DecodeReader.byteCount);
Dbprintf(" DecodeReader posCount: %d", DecodeReader.posCount);
Dbprintf(" Trace length: %d", BigBuf_get_traceLen());
Dbprintf(" Max behindBy: %d", max_behindBy);
}
// Initialize Proxmark3 as ISO15693 reader
void Iso15693InitReader(void) {
LEDsoff();
FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
// Start from off (no field generated)
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
SpinDelay(10);
// switch field on
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_READER);
LED_D_ON();
// initialize SSC and select proper AD input
FpgaSetupSsc(FPGA_MAJOR_MODE_HF_READER);
SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
set_tracing(true);
// give tags some time to energize
SpinDelay(250);
StartCountSspClk();
}
///////////////////////////////////////////////////////////////////////
// ISO 15693 Part 3 - Air Interface
// This section basicly contains transmission and receiving of bits
///////////////////////////////////////////////////////////////////////
// Encode an identify request, which is the first
// thing that you must send to a tag to get a response.
// It expects "cmdout" to be at least CMD_ID_RESP large
// When READER:
static void BuildIdentifyRequest(uint8_t *cmd) {
// flags
cmd[0] = ISO15_REQ_SUBCARRIER_SINGLE | ISO15_REQ_DATARATE_HIGH | ISO15_REQ_INVENTORY | ISO15_REQINV_SLOT1;
// inventory command code
cmd[1] = ISO15_CMD_INVENTORY;
// no mask
cmd[2] = 0x00;
// CRC
AddCrc15(cmd, 3);
}
// Universal Method for sending to and recv bytes from a tag
// init ... should we initialize the reader?
// speed ... 0 low speed, 1 hi speed
// **recv will return you a pointer to the received data
// If you do not need the answer use NULL for *recv[]
// return: length of received data
// logging enabled
int SendDataTag(uint8_t *send, int sendlen, bool init, bool speed_fast, uint8_t *recv,
uint16_t max_recv_len, uint32_t start_time, uint16_t timeout, uint32_t *eof_time) {
if (init) {
Iso15693InitReader();
}
if (speed_fast) {
// high speed (1 out of 4)
CodeIso15693AsReader(send, sendlen);
} else {
// low speed (1 out of 256)
CodeIso15693AsReader256(send, sendlen);
}
tosend_t *ts = get_tosend();
TransmitTo15693Tag(ts->buf, ts->max, &start_time);
uint32_t end_time = start_time + 32 * ((8 * ts->max) - 4); // substract the 4 padding bits after EOF
LogTrace(send, sendlen, (start_time * 4), (end_time * 4), NULL, true);
int res = 0;
if (recv != NULL) {
res = GetIso15693AnswerFromTag(recv, max_recv_len, timeout, eof_time);
}
return res;
}
int SendDataTagEOF(uint8_t *recv, uint16_t max_recv_len, uint32_t start_time, uint16_t timeout, uint32_t *eof_time) {
CodeIso15693AsReaderEOF();
tosend_t *ts = get_tosend();
TransmitTo15693Tag(ts->buf, ts->max, &start_time);
uint32_t end_time = start_time + 32 * (8 * ts->max - 4); // substract the 4 padding bits after EOF
LogTrace(NULL, 0, (start_time * 4), (end_time * 4), NULL, true);
int res = 0;
if (recv != NULL) {
res = GetIso15693AnswerFromTag(recv, max_recv_len, timeout, eof_time);
}
return res;
}
// --------------------------------------------------------------------
// Debug Functions
// --------------------------------------------------------------------
// Decodes a message from a tag and displays its metadata and content
#define DBD15STATLEN 48
static void DbdecodeIso15693Answer(int len, uint8_t *d) {
if (len > 3) {
char status[DBD15STATLEN + 1] = {0};
if (d[0] & ISO15_RES_EXT)
strncat(status, "ProtExt ", DBD15STATLEN - strlen(status));
if (d[0] & ISO15_RES_ERROR) {
// error
strncat(status, "Error ", DBD15STATLEN - strlen(status));
switch (d[1]) {
case 0x01:
strncat(status, "01: not supported", DBD15STATLEN - strlen(status));
break;
case 0x02:
strncat(status, "02: not recognized", DBD15STATLEN - strlen(status));
break;
case 0x03:
strncat(status, "03: opt not supported", DBD15STATLEN - strlen(status));
break;
case 0x0f:
strncat(status, "0F: no info", DBD15STATLEN - strlen(status));
break;
case 0x10:
strncat(status, "10: don't exist", DBD15STATLEN - strlen(status));
break;
case 0x11:
strncat(status, "11: lock again", DBD15STATLEN - strlen(status));
break;
case 0x12:
strncat(status, "12: locked", DBD15STATLEN - strlen(status));
break;
case 0x13:
strncat(status, "13: program error", DBD15STATLEN - strlen(status));
break;
case 0x14:
strncat(status, "14: lock error", DBD15STATLEN - strlen(status));
break;
default:
strncat(status, "unknown error", DBD15STATLEN - strlen(status));
}
strncat(status, " ", DBD15STATLEN - strlen(status));
} else {
strncat(status, "No error ", DBD15STATLEN - strlen(status));
}
if (CheckCrc15(d, len))
strncat(status, "[+] crc (" _GREEN_("OK") ")", DBD15STATLEN - strlen(status));
else
strncat(status, "[!] crc (" _RED_("fail") ")", DBD15STATLEN - strlen(status));
if (DBGLEVEL >= DBG_ERROR) Dbprintf("%s", status);
}
}
///////////////////////////////////////////////////////////////////////
// Functions called via USB/Client
///////////////////////////////////////////////////////////////////////
//-----------------------------------------------------------------------------
// Act as ISO15693 reader, perform anti-collision and then attempt to read a sector
// all demodulation performed in arm rather than host. - greg
//-----------------------------------------------------------------------------
// ok
// parameter is unused !?!
void ReaderIso15693(uint32_t parameter) {
LED_A_ON();
set_tracing(true);
uint8_t *answer = BigBuf_malloc(ISO15693_MAX_RESPONSE_LENGTH);
memset(answer, 0x00, ISO15693_MAX_RESPONSE_LENGTH);
// FIRST WE RUN AN INVENTORY TO GET THE TAG UID
// THIS MEANS WE CAN PRE-BUILD REQUESTS TO SAVE CPU TIME
// Send the IDENTIFY command
uint8_t cmd[5] = {0};
BuildIdentifyRequest(cmd);
uint32_t start_time = 0;
uint32_t eof_time;
int answerLen = SendDataTag(cmd, sizeof(cmd), true, true, answer, ISO15693_MAX_RESPONSE_LENGTH, start_time, ISO15693_READER_TIMEOUT, &eof_time);
start_time = eof_time + DELAY_ISO15693_VICC_TO_VCD_READER;
// we should do a better check than this
if (answerLen >= 12) {
uint8_t uid[8];
uid[0] = answer[9]; // always E0
uid[1] = answer[8]; // IC Manufacturer code
uid[2] = answer[7];
uid[3] = answer[6];
uid[4] = answer[5];
uid[5] = answer[4];
uid[6] = answer[3];
uid[7] = answer[2];
if (DBGLEVEL >= DBG_EXTENDED) {
Dbprintf("[+] UID = %02X%02X%02X%02X%02X%02X%02X%02X",
uid[0], uid[1], uid[2], uid[3],
uid[4], uid[5], uid[5], uid[6]
);
}
// send UID back to client.
// arg0 = 1 = OK
// arg1 = len of response (12 bytes)
// arg2 = rtf
// asbytes = uid.
reply_mix(CMD_ACK, 1, sizeof(uid), 0, uid, sizeof(uid));
}
if (DBGLEVEL >= DBG_EXTENDED) {
Dbprintf("[+] %d octets read from IDENTIFY request:", answerLen);
DbdecodeIso15693Answer(answerLen, answer);
Dbhexdump(answerLen, answer, true);
}
switch_off();
BigBuf_free();
}
// When SIM: initialize the Proxmark3 as ISO15693 tag
void Iso15693InitTag(void) {
FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
// Start from off (no field generated)
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
LEDsoff();
SpinDelay(10);
// switch simulation FPGA
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_SIMULATOR | FPGA_HF_SIMULATOR_NO_MODULATION);
// initialize SSC and select proper AD input
FpgaSetupSsc(FPGA_MAJOR_MODE_HF_SIMULATOR);
SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
clear_trace();
set_tracing(true);
StartCountSspClk();
}
// Simulate an ISO15693 TAG, perform anti-collision and then print any reader commands
// all demodulation performed in arm rather than host. - greg
void SimTagIso15693(uint8_t *uid) {
// free eventually allocated BigBuf memory
BigBuf_free_keep_EM();
Iso15693InitTag();
LED_A_ON();
Dbprintf("ISO-15963 Simulating uid: %02X%02X%02X%02X%02X%02X%02X%02X", uid[0], uid[1], uid[2], uid[3], uid[4], uid[5], uid[6], uid[7]);
LED_C_ON();
// Build INVENTORY command
uint8_t resp_inv[CMD_INV_RESP] = {0};
resp_inv[0] = 0; // No error, no protocol format extension
resp_inv[1] = 0; // DSFID (data storage format identifier). 0x00 = not supported
// 64-bit UID
resp_inv[2] = uid[7];
resp_inv[3] = uid[6];
resp_inv[4] = uid[5];
resp_inv[5] = uid[4];
resp_inv[6] = uid[3];
resp_inv[7] = uid[2];
resp_inv[8] = uid[1];
resp_inv[9] = uid[0];
// CRC
AddCrc15(resp_inv, 10);
CodeIso15693AsTag(resp_inv, CMD_INV_RESP);
tosend_t *ts = get_tosend();
enum { NO_FIELD, IDLE, ACTIVATED, SELECTED, HALTED } chip_state = NO_FIELD;
bool button_pressed = false;
int vHf = 0; // in mV
bool exit_loop = false;
while (exit_loop == false) {
WDT_HIT();
// find reader field
if (chip_state == NO_FIELD) {
#if defined RDV4
vHf = (MAX_ADC_HF_VOLTAGE_RDV40 * SumAdc(ADC_CHAN_HF_RDV40, 32)) >> 15;
#else
vHf = (MAX_ADC_HF_VOLTAGE * SumAdc(ADC_CHAN_HF, 32)) >> 15;
#endif
if (vHf > MF_MINFIELDV) {
chip_state = IDLE;
LED_A_ON();
} else {
continue;
}
}
// Listen to reader
uint8_t cmd[ISO15693_MAX_COMMAND_LENGTH];
uint32_t reader_eof_time = 0;
int cmd_len = GetIso15693CommandFromReader(cmd, sizeof(cmd), &reader_eof_time);
if (cmd_len < 0) {
Dbprintf("button pressed, exiting");
button_pressed = true;
exit_loop = true;
break;
}
// TODO: check more flags
if ((cmd_len >= 5) && (cmd[0] & ISO15_REQ_INVENTORY) && (cmd[1] == ISO15_CMD_INVENTORY)) {
bool slow = !(cmd[0] & ISO15_REQ_DATARATE_HIGH);
uint32_t response_time = reader_eof_time + DELAY_ISO15693_VCD_TO_VICC_SIM;
TransmitTo15693Reader(ts->buf, ts->max, &response_time, 0, slow);
LogTrace(resp_inv, CMD_INV_RESP, response_time * 32, (response_time * 32) + (ts->max * 32 * 64), NULL, false);
chip_state = SELECTED;
}
}
switch_off();
if (button_pressed)
DbpString("button pressed");
}
// Since there is no standardized way of reading the AFI out of a tag, we will brute force it
// (some manufactures offer a way to read the AFI, though)
void BruteforceIso15693Afi(uint32_t speed) {
uint8_t data[7] = {0};
uint8_t recv[ISO15693_MAX_RESPONSE_LENGTH];
Iso15693InitReader();
// first without AFI
// Tags should respond wihtout AFI and with AFI=0 even when AFI is active
data[0] = ISO15_REQ_SUBCARRIER_SINGLE | ISO15_REQ_DATARATE_HIGH | ISO15_REQ_INVENTORY | ISO15_REQINV_SLOT1;
data[1] = ISO15_CMD_INVENTORY;
data[2] = 0; // AFI
AddCrc15(data, 3);
int datalen = 5;
uint32_t eof_time = 0;
uint32_t start_time = GetCountSspClk();
int recvlen = SendDataTag(data, datalen, true, speed, recv, sizeof(recv), 0, ISO15693_READER_TIMEOUT, &eof_time);
start_time = eof_time + DELAY_ISO15693_VICC_TO_VCD_READER;
WDT_HIT();
if (recvlen >= 12) {
Dbprintf("NoAFI UID = %s", iso15693_sprintUID(NULL, recv + 2));
}
// now with AFI
data[0] |= ISO15_REQINV_AFI;
data[2] = 0; // AFI
data[3] = 0; // mask length
// 4 + 2crc
datalen = 6;
bool aborted = false;
for (uint16_t i = 0; i < 256; i++) {
data[2] = i & 0xFF;
AddCrc15(data, 4);
recvlen = SendDataTag(data, datalen, false, speed, recv, sizeof(recv), start_time, ISO15693_READER_TIMEOUT, &eof_time);
start_time = eof_time + DELAY_ISO15693_VICC_TO_VCD_READER;
WDT_HIT();
if (recvlen >= 12) {
Dbprintf("AFI = %i UID = %s", i, iso15693_sprintUID(NULL, recv + 2));
}
aborted = BUTTON_PRESS();
if (aborted) {
DbpString("button pressed, aborting..");
break;
}
}
DbpString("AFI Bruteforcing done.");
switch_off();
if (aborted) {
reply_ng(CMD_ACK, PM3_EOPABORTED, NULL, 0);
} else {
reply_ng(CMD_ACK, PM3_SUCCESS, NULL, 0);
}
}
// Allows to directly send commands to the tag via the client
// OBS: doesn't turn off rf field afterwards.
void DirectTag15693Command(uint32_t datalen, uint32_t speed, uint32_t recv, uint8_t *data) {
LED_A_ON();
int recvlen = 0;
uint8_t recvbuf[ISO15693_MAX_RESPONSE_LENGTH];
uint32_t eof_time;
uint16_t timeout;
bool request_answer = false;
switch (data[1]) {
case ISO15_CMD_WRITE:
case ISO15_CMD_LOCK:
case ISO15_CMD_WRITEMULTI:
case ISO15_CMD_WRITEAFI:
case ISO15_CMD_LOCKAFI:
case ISO15_CMD_WRITEDSFID:
case ISO15_CMD_LOCKDSFID:
timeout = ISO15693_READER_TIMEOUT_WRITE;
request_answer = data[0] & ISO15_REQ_OPTION;
break;
default:
timeout = ISO15693_READER_TIMEOUT;
}
if (DBGLEVEL >= DBG_EXTENDED) {
Dbprintf("SEND:");
Dbhexdump(datalen, data, false);
}
recvlen = SendDataTag(data, datalen, true, speed, (recv ? recvbuf : NULL), sizeof(recvbuf), 0, timeout, &eof_time);
// send a single EOF to get the tag response
if (request_answer) {
recvlen = SendDataTagEOF((recv ? recvbuf : NULL), sizeof(recvbuf), 0, ISO15693_READER_TIMEOUT, &eof_time);
}
// for the time being, switch field off to protect rdv4.0
// note: this prevents using hf 15 cmd with s option - which isn't implemented yet anyway
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
LED_D_OFF();
if (recv) {
if (recvlen > ISO15693_MAX_RESPONSE_LENGTH) {
recvlen = ISO15693_MAX_RESPONSE_LENGTH;
}
reply_mix(CMD_ACK, recvlen, 0, 0, recvbuf, ISO15693_MAX_RESPONSE_LENGTH);
if (DBGLEVEL >= DBG_EXTENDED) {
Dbprintf("RECV:");
if (recvlen > 0) {
Dbhexdump(recvlen, recvbuf, false);
DbdecodeIso15693Answer(recvlen, recvbuf);
}
}
} else {
reply_mix(CMD_ACK, 1, 0, 0, 0, 0);
}
}
//-----------------------------------------------------------------------------
// Work with "magic Chinese" card.
//
//-----------------------------------------------------------------------------
// Set the UID on Magic ISO15693 tag (based on Iceman's LUA-script).
void SetTag15693Uid(uint8_t *uid) {
LED_A_ON();
uint8_t cmd[4][9] = {
{ISO15_REQ_DATARATE_HIGH, ISO15_CMD_WRITE, 0x3e, 0x00, 0x00, 0x00, 0x00},
{ISO15_REQ_DATARATE_HIGH, ISO15_CMD_WRITE, 0x3f, 0x69, 0x96, 0x00, 0x00},
{ISO15_REQ_DATARATE_HIGH, ISO15_CMD_WRITE, 0x38},
{ISO15_REQ_DATARATE_HIGH, ISO15_CMD_WRITE, 0x39}
};
int recvlen = 0;
uint8_t recvbuf[ISO15693_MAX_RESPONSE_LENGTH];
uint32_t eof_time;
// Command 3 : 022138u8u7u6u5 (where uX = uid byte X)
cmd[2][3] = uid[7];
cmd[2][4] = uid[6];
cmd[2][5] = uid[5];
cmd[2][6] = uid[4];
// Command 4 : 022139u4u3u2u1 (where uX = uid byte X)
cmd[3][3] = uid[3];
cmd[3][4] = uid[2];
cmd[3][5] = uid[1];
cmd[3][6] = uid[0];
AddCrc15(cmd[0], 7);
AddCrc15(cmd[1], 7);
AddCrc15(cmd[2], 7);
AddCrc15(cmd[3], 7);
uint32_t start_time = 0;
for (int i = 0; i < 4; i++) {
recvlen = SendDataTag(cmd[i], sizeof(cmd[i]), i == 0 ? true : false, true, recvbuf, sizeof(recvbuf), start_time, ISO15693_READER_TIMEOUT_WRITE, &eof_time);
start_time = eof_time + DELAY_ISO15693_VICC_TO_VCD_READER;
if (DBGLEVEL >= DBG_EXTENDED) {
Dbprintf("SEND:");
Dbhexdump(sizeof(cmd[i]), cmd[i], false);
Dbprintf("RECV:");
if (recvlen > 0) {
Dbhexdump(recvlen, recvbuf, false);
DbdecodeIso15693Answer(recvlen, recvbuf);
}
}
}
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
LEDsoff();
reply_mix(CMD_ACK, recvlen, 0, 0, recvbuf, recvlen);
}
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