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iclass.c
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//-----------------------------------------------------------------------------
// Gerhard de Koning Gans - May 2008
// Hagen Fritsch - June 2010
// Gerhard de Koning Gans - May 2011
// Gerhard de Koning Gans - June 2012 - Added iClass card and reader emulation
//
// 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 iClass.
//-----------------------------------------------------------------------------
// Based on ISO14443a implementation. Still in experimental phase.
// Contribution made during a security research at Radboud University Nijmegen
//
// Please feel free to contribute and extend iClass support!!
//-----------------------------------------------------------------------------
//
// FIX:
// ====
// We still have sometimes a demodulation error when sniffing iClass communication.
// The resulting trace of a read-block-03 command may look something like this:
//
// + 22279: : 0c 03 e8 01
//
// ...with an incorrect answer...
//
// + 85: 0: TAG ff! ff! ff! ff! ff! ff! ff! ff! bb 33 bb 00 01! 0e! 04! bb !crc
//
// We still left the error signalling bytes in the traces like 0xbb
//
// A correct trace should look like this:
//
// + 21112: : 0c 03 e8 01
// + 85: 0: TAG ff ff ff ff ff ff ff ff ea f5
//
//-----------------------------------------------------------------------------
#include "apps.h"
#include "cmd.h"
// Needed for CRC in emulation mode;
// same construction as in ISO 14443;
// different initial value (CRC_ICLASS)
#include "crc16.h"
#include "protocols.h"
#include "optimized_cipher.h"
#include "usb_cdc.h" // for usb_poll_validate_length
static int timeout = 4096;
static int SendIClassAnswer(uint8_t *resp, int respLen, uint16_t delay);
int doIClassSimulation(int simulationMode, uint8_t *reader_mac_buf);
#define MODE_SIM_CSN 0
#define MODE_EXIT_AFTER_MAC 1
#define MODE_FULLSIM 2
#ifndef ICLASS_DMA_BUFFER_SIZE
# define ICLASS_DMA_BUFFER_SIZE 256
#endif
// The length of a received command will in most cases be no more than 18 bytes.
// 32 should be enough!
#ifndef ICLASS_BUFFER_SIZE
#define ICLASS_BUFFER_SIZE 32
#endif
#define AddCrc(data, len) compute_crc(CRC_ICLASS, (data), (len), (data)+(len), (data)+(len)+1)
//-----------------------------------------------------------------------------
// The software UART that receives commands from the reader, and its state
// variables.
//-----------------------------------------------------------------------------
/*
typedef struct {
enum {
STATE_UNSYNCD,
STATE_START_OF_COMMUNICATION,
STATE_RECEIVING
} state;
uint16_t shiftReg;
int bitCnt;
int byteCnt;
// int byteCntMax;
int posCnt;
int nOutOfCnt;
int OutOfCnt;
int syncBit;
int samples;
int highCnt;
int swapper;
int counter;
int bitBuffer;
int dropPosition;
uint8_t *output;
} tUart;
*/
typedef struct {
enum {
DEMOD_UNSYNCD,
DEMOD_START_OF_COMMUNICATION,
DEMOD_START_OF_COMMUNICATION2,
DEMOD_START_OF_COMMUNICATION3,
DEMOD_SOF_COMPLETE,
DEMOD_MANCHESTER_D,
DEMOD_MANCHESTER_E,
DEMOD_END_OF_COMMUNICATION,
DEMOD_END_OF_COMMUNICATION2,
DEMOD_MANCHESTER_F,
DEMOD_ERROR_WAIT
} state;
int bitCount;
int posCount;
int syncBit;
uint16_t shiftReg;
uint32_t buffer;
uint32_t buffer2;
uint32_t buffer3;
int buff;
int samples;
int len;
enum {
SUB_NONE,
SUB_FIRST_HALF,
SUB_SECOND_HALF,
SUB_BOTH
} sub;
uint8_t *output;
} tDemod;
/*
* Abrasive's uart implementation
* https://github.com/abrasive/proxmark3/commit/2b8bff7daea8ae1193bf7ee29b1fa46e95218902
*/
// Static vars for UART
typedef struct {
bool synced;
bool frame;
bool frame_done;
uint8_t *buf;
int len;
} tUart;
static tUart Uart;
static void uart_reset(void) {
Uart.frame_done = false;
Uart.synced = false;
Uart.frame = false;
}
static void uart_init(uint8_t *data) {
Uart.buf = data;
uart_reset();
}
static void uart_bit(uint8_t bit) {
static uint8_t buf = 0xff;
static uint8_t n_buf;
static uint8_t msg_byte;
static int nmsg_byte;
buf <<= 1;
buf |= bit ? 1 : 0;
if (!Uart.frame) {
if (buf == 0x7b) { // 0b0111 1011
Uart.frame = true;
n_buf = 0;
Uart.len = 0;
nmsg_byte = 0;
}
} else {
n_buf++;
if (n_buf == 8) {
msg_byte >>= 2;
switch (buf) {
case 0xbf: // 0 - 1011 1111
break;
case 0xef: // 1 - 1110 1111
msg_byte |= (1 << 6);
break;
case 0xfb: // 2 - 1111 1011
msg_byte |= (2 << 6);
break;
case 0xfe: // 3 - 1111 1110
msg_byte |= (3 << 6);
break;
case 0xdf: // eof - 1101 1111
Uart.frame = false;
Uart.synced = false;
Uart.frame_done = true;
break;
default:
Uart.frame = false;
Uart.synced = false;
Dbprintf("[-] bad %02X at %d:%d", buf, Uart.len, nmsg_byte);
}
if (Uart.frame) { // data bits
nmsg_byte += 2;
if (nmsg_byte >= 8) {
Uart.buf[Uart.len++] = msg_byte;
nmsg_byte = 0;
}
}
n_buf = 0;
buf = 0xff;
}
}
}
static void uart_samples(uint8_t byte) {
static uint32_t buf;
static int window;
static int drop_next = 0;
uint32_t falling;
int lz;
if (!Uart.synced) {
if (byte == 0xFF)
return;
buf = 0xFFFFFFFF;
window = 0;
drop_next = 0;
Uart.synced = true;
}
buf <<= 8;
buf |= byte;
if (drop_next) {
drop_next = 0;
return;
}
again:
falling = ~buf & ((buf >> 1) ^ buf) & (0xFF << window);
uart_bit(!falling);
if (!falling)
return;
lz = __builtin_clz(falling) - 24 + window;
// aim to get falling edge on fourth-leftmost bit of window
window += 3 - lz;
if (window < 0) {
window += 8;
drop_next = 1;
} else if (window >= 8) {
window -= 8;
goto again;
}
}
/*
static void UartReset(){
Uart.state = STATE_UNSYNCD;
Uart.shiftReg = 0;
Uart.bitCnt = 0;
Uart.byteCnt = 0;
Uart.posCnt = 0;
Uart.nOutOfCnt = 0;
Uart.OutOfCnt = 0;
Uart.syncBit = 0;
Uart.samples = 0;
Uart.highCnt = 0;
Uart.swapper = 0;
Uart.counter = 0;
Uart.bitBuffer = 0;
Uart.dropPosition = 0;
}
*/
/*
* READER TO CARD
* 1 out of 4 Decoding
* 1 out of 256 Decoding
*/
/*
static RAMFUNC int OutOfNDecoding(int bit) {
//int error = 0;
int bitright;
if (!Uart.bitBuffer) {
Uart.bitBuffer = bit ^ 0xFF0;
return false;
} else {
Uart.bitBuffer <<= 4;
Uart.bitBuffer ^= bit;
}
// if (Uart.swapper) {
// Uart.output[Uart.byteCnt] = Uart.bitBuffer & 0xFF;
// Uart.byteCnt++;
// Uart.swapper = 0;
// if (Uart.byteCnt > 15) return true;
// }
// else {
// Uart.swapper = 1;
// }
if (Uart.state != STATE_UNSYNCD) {
Uart.posCnt++;
if ((Uart.bitBuffer & Uart.syncBit) ^ Uart.syncBit)
bit = 0;
else
bit = 1;
if (((Uart.bitBuffer << 1) & Uart.syncBit) ^ Uart.syncBit)
bitright = 0;
else
bitright = 1;
if(bit != bitright)
bit = bitright;
// So, now we only have to deal with *bit*, lets see...
if (Uart.posCnt == 1) {
// measurement first half bitperiod
if (!bit) {
// Drop in first half means that we are either seeing
// an SOF or an EOF.
if (Uart.nOutOfCnt == 1) {
// End of Communication
Uart.state = STATE_UNSYNCD;
Uart.highCnt = 0;
if (Uart.byteCnt == 0) {
// Its not straightforward to show single EOFs
// So just leave it and do not return TRUE
Uart.output[0] = 0xf0;
Uart.byteCnt++;
} else {
return true;
}
} else if (Uart.state != STATE_START_OF_COMMUNICATION) {
// When not part of SOF or EOF, it is an error
Uart.state = STATE_UNSYNCD;
Uart.highCnt = 0;
//error = 4;
}
}
} else {
// measurement second half bitperiod
// Count the bitslot we are in... (ISO 15693)
Uart.nOutOfCnt++;
if (!bit) {
if (Uart.dropPosition) {
if (Uart.state == STATE_START_OF_COMMUNICATION) {
//error = 1;
} else {
//error = 7;
}
// It is an error if we already have seen a drop in current frame
Uart.state = STATE_UNSYNCD;
Uart.highCnt = 0;
} else {
Uart.dropPosition = Uart.nOutOfCnt;
}
}
Uart.posCnt = 0;
if (Uart.nOutOfCnt == Uart.OutOfCnt && Uart.OutOfCnt == 4) {
Uart.nOutOfCnt = 0;
if (Uart.state == STATE_START_OF_COMMUNICATION) {
if (Uart.dropPosition == 4) {
Uart.state = STATE_RECEIVING;
Uart.OutOfCnt = 256;
} else if (Uart.dropPosition == 3) {
Uart.state = STATE_RECEIVING;
Uart.OutOfCnt = 4;
//Uart.output[Uart.byteCnt] = 0xdd;
//Uart.byteCnt++;
} else {
Uart.state = STATE_UNSYNCD;
Uart.highCnt = 0;
}
Uart.dropPosition = 0;
} else {
// RECEIVING DATA
// 1 out of 4
if (!Uart.dropPosition) {
Uart.state = STATE_UNSYNCD;
Uart.highCnt = 0;
//error = 9;
} else {
Uart.shiftReg >>= 2;
// Swap bit order
Uart.dropPosition--;
//if(Uart.dropPosition == 1) { Uart.dropPosition = 2; }
//else if(Uart.dropPosition == 2) { Uart.dropPosition = 1; }
Uart.shiftReg ^= ((Uart.dropPosition & 0x03) << 6);
Uart.bitCnt += 2;
Uart.dropPosition = 0;
if (Uart.bitCnt == 8) {
Uart.output[Uart.byteCnt] = (Uart.shiftReg & 0xff);
Uart.byteCnt++;
Uart.bitCnt = 0;
Uart.shiftReg = 0;
}
}
}
} else if (Uart.nOutOfCnt == Uart.OutOfCnt) {
// RECEIVING DATA
// 1 out of 256
if (!Uart.dropPosition) {
Uart.state = STATE_UNSYNCD;
Uart.highCnt = 0;
//error = 3;
} else {
Uart.dropPosition--;
Uart.output[Uart.byteCnt] = (Uart.dropPosition & 0xff);
Uart.byteCnt++;
Uart.bitCnt = 0;
Uart.shiftReg = 0;
Uart.nOutOfCnt = 0;
Uart.dropPosition = 0;
}
}
*/
/*if (error) {
Uart.output[Uart.byteCnt] = 0xAA;
Uart.byteCnt++;
Uart.output[Uart.byteCnt] = error & 0xFF;
Uart.byteCnt++;
Uart.output[Uart.byteCnt] = 0xAA;
Uart.byteCnt++;
Uart.output[Uart.byteCnt] = (Uart.bitBuffer >> 8) & 0xFF;
Uart.byteCnt++;
Uart.output[Uart.byteCnt] = Uart.bitBuffer & 0xFF;
Uart.byteCnt++;
Uart.output[Uart.byteCnt] = (Uart.syncBit >> 3) & 0xFF;
Uart.byteCnt++;
Uart.output[Uart.byteCnt] = 0xAA;
Uart.byteCnt++;
return true;
}*/
/*
}
} else {
bit = Uart.bitBuffer & 0xf0;
bit >>= 4;
bit ^= 0x0F; // drops become 1s ;-)
if (bit) {
// should have been high or at least (4 * 128) / fc
// according to ISO this should be at least (9 * 128 + 20) / fc
if (Uart.highCnt == 8) {
// we went low, so this could be start of communication
// it turns out to be safer to choose a less significant
// syncbit... so we check whether the neighbour also represents the drop
Uart.posCnt = 1; // apparently we are busy with our first half bit period
Uart.syncBit = bit & 8;
Uart.samples = 3;
if (!Uart.syncBit) { Uart.syncBit = bit & 4; Uart.samples = 2; }
else if (bit & 4) { Uart.syncBit = bit & 4; Uart.samples = 2; bit <<= 2; }
if (!Uart.syncBit) { Uart.syncBit = bit & 2; Uart.samples = 1; }
else if (bit & 2) { Uart.syncBit = bit & 2; Uart.samples = 1; bit <<= 1; }
if (!Uart.syncBit) { Uart.syncBit = bit & 1; Uart.samples = 0;
if (Uart.syncBit && (Uart.bitBuffer & 8)) {
Uart.syncBit = 8;
// the first half bit period is expected in next sample
Uart.posCnt = 0;
Uart.samples = 3;
}
} else if (bit & 1) { Uart.syncBit = bit & 1; Uart.samples = 0; }
Uart.syncBit <<= 4;
Uart.state = STATE_START_OF_COMMUNICATION;
Uart.bitCnt = 0;
Uart.byteCnt = 0;
Uart.nOutOfCnt = 0;
Uart.OutOfCnt = 4; // Start at 1/4, could switch to 1/256
Uart.dropPosition = 0;
Uart.shiftReg = 0;
//error = 0;
} else {
Uart.highCnt = 0;
}
} else {
if (Uart.highCnt < 8)
Uart.highCnt++;
}
}
return false;
}
*/
//=============================================================================
// Manchester
//=============================================================================
static tDemod Demod;
static void DemodReset() {
Demod.bitCount = 0;
Demod.posCount = 0;
Demod.syncBit = 0;
Demod.shiftReg = 0;
Demod.buffer = 0;
Demod.buffer2 = 0;
Demod.buffer3 = 0;
Demod.buff = 0;
Demod.samples = 0;
Demod.len = 0;
Demod.sub = SUB_NONE;
Demod.state = DEMOD_UNSYNCD;
}
static void DemodInit(uint8_t *data) {
Demod.output = data;
DemodReset();
}
// UART debug
// it adds the debug values which will be put in the tracelog,
// visible on client when running 'hf list iclass'
/*
pm3 --> hf li iclass
Recorded Activity (TraceLen = 162 bytes)
Start | End | Src | Data (! denotes parity error) | CRC | Annotation |
------------|------------|-----|-----------------------------------------------------------------|-----|--------------------|
0 | 0 | Rdr |0a | | ACTALL
1280 | 1280 | Tag |bb! 33! bb! 01 02 04 08 bb! | ok |
1280 | 1280 | Rdr |0c | | IDENTIFY
1616 | 1616 | Tag |bb! 33! bb! 00! 02 00! 02 bb! | ok |
1616 | 1616 | Rdr |0a | | ACTALL
2336 | 2336 | Tag |bb! d4! bb! 02 08 00! 08 bb! | ok |
2336 | 2336 | Rdr |0c | | IDENTIFY
2448 | 2448 | Tag |bb! 33! bb! 00! 00! 00! 02 bb! | ok |
2448 | 2448 | Rdr |0a | | ACTALL
2720 | 2720 | Tag |bb! d4! bb! 08 0b 01 04 bb! | ok |
2720 | 2720 | Rdr |0c | | IDENTIFY
3232 | 3232 | Tag |bb! d4! bb! 02 02 08 04 bb! | ok |
*/
static void uart_debug(int error, int bit) {
Demod.output[Demod.len] = 0xBB;
Demod.len++;
Demod.output[Demod.len] = error & 0xFF;
Demod.len++;
Demod.output[Demod.len] = 0xBB;
Demod.len++;
Demod.output[Demod.len] = bit & 0xFF;
Demod.len++;
Demod.output[Demod.len] = Demod.buffer & 0xFF;
Demod.len++;
// Look harder ;-)
Demod.output[Demod.len] = Demod.buffer2 & 0xFF;
Demod.len++;
Demod.output[Demod.len] = Demod.syncBit & 0xFF;
Demod.len++;
Demod.output[Demod.len] = 0xBB;
Demod.len++;
}
/*
* CARD TO READER
* in ISO15693-2 mode - Manchester
* in ISO 14443b - BPSK coding
*
* Timings:
* ISO 15693-2
* Tout = 330 µs, Tprog 1 = 4 to 15 ms, Tslot = 330 µs + (number of slots x 160 µs)
* ISO 14443a
* Tout = 100 µs, Tprog = 4 to 15 ms, Tslot = 100 µs+ (number of slots x 80 µs)
* ISO 14443b
Tout = 76 µs, Tprog = 4 to 15 ms, Tslot = 119 µs+ (number of slots x 150 µs)
*
*
* So for current implementation in ISO15693, its 330 µs from end of reader, to start of card.
*/
static RAMFUNC int ManchesterDecoding_iclass(uint32_t v) {
int bit;
int modulation;
int error = 0;
bit = Demod.buffer;
Demod.buffer = Demod.buffer2;
Demod.buffer2 = Demod.buffer3;
Demod.buffer3 = v;
// too few bits?
if (Demod.buff < 3) {
Demod.buff++;
return false;
}
if (Demod.state == DEMOD_UNSYNCD) {
Demod.output[Demod.len] = 0xfa;
Demod.syncBit = 0;
//Demod.samples = 0;
Demod.posCount = 1; // This is the first half bit period, so after syncing handle the second part
if (bit & 0x08)
Demod.syncBit = 0x08;
if (bit & 0x04) {
if (Demod.syncBit)
bit <<= 4;
Demod.syncBit = 0x04;
}
if (bit & 0x02) {
if (Demod.syncBit)
bit <<= 2;
Demod.syncBit = 0x02;
}
if (bit & 0x01 && Demod.syncBit)
Demod.syncBit = 0x01;
if (Demod.syncBit) {
Demod.len = 0;
Demod.state = DEMOD_START_OF_COMMUNICATION;
Demod.sub = SUB_FIRST_HALF;
Demod.bitCount = 0;
Demod.shiftReg = 0;
Demod.samples = 0;
if (Demod.posCount) {
switch (Demod.syncBit) {
case 0x08:
Demod.samples = 3;
break;
case 0x04:
Demod.samples = 2;
break;
case 0x02:
Demod.samples = 1;
break;
case 0x01:
Demod.samples = 0;
break;
}
// SOF must be long burst... otherwise stay unsynced!!!
if (!(Demod.buffer & Demod.syncBit) || !(Demod.buffer2 & Demod.syncBit))
Demod.state = DEMOD_UNSYNCD;
} else {
// SOF must be long burst... otherwise stay unsynced!!!
if (!(Demod.buffer2 & Demod.syncBit) || !(Demod.buffer3 & Demod.syncBit)) {
Demod.state = DEMOD_UNSYNCD;
error = 0x88;
uart_debug(error, bit);
return false;
}
}
error = 0;
}
return false;
}
// state is DEMOD is in SYNC from here on.
modulation = bit & Demod.syncBit;
modulation |= ((bit << 1) ^ ((Demod.buffer & 0x08) >> 3)) & Demod.syncBit;
Demod.samples += 4;
if (Demod.posCount == 0) {
Demod.posCount = 1;
Demod.sub = (modulation) ? SUB_FIRST_HALF : SUB_NONE;
return false;
}
Demod.posCount = 0;
if (modulation) {
if (Demod.sub == SUB_FIRST_HALF)
Demod.sub = SUB_BOTH;
else
Demod.sub = SUB_SECOND_HALF;
}
if (Demod.sub == SUB_NONE) {
if (Demod.state == DEMOD_SOF_COMPLETE) {
Demod.output[Demod.len] = 0x0f;
Demod.len++;
Demod.state = DEMOD_UNSYNCD;
return true;
} else {
Demod.state = DEMOD_ERROR_WAIT;
error = 0x33;
}
}
switch (Demod.state) {
case DEMOD_START_OF_COMMUNICATION:
if (Demod.sub == SUB_BOTH) {
Demod.state = DEMOD_START_OF_COMMUNICATION2;
Demod.posCount = 1;
Demod.sub = SUB_NONE;
} else {
Demod.output[Demod.len] = 0xab;
Demod.state = DEMOD_ERROR_WAIT;
error = 0xd2;
}
break;
case DEMOD_START_OF_COMMUNICATION2:
if (Demod.sub == SUB_SECOND_HALF) {
Demod.state = DEMOD_START_OF_COMMUNICATION3;
} else {
Demod.output[Demod.len] = 0xab;
Demod.state = DEMOD_ERROR_WAIT;
error = 0xd3;
}
break;
case DEMOD_START_OF_COMMUNICATION3:
if (Demod.sub == SUB_SECOND_HALF) {
Demod.state = DEMOD_SOF_COMPLETE;
} else {
Demod.output[Demod.len] = 0xab;
Demod.state = DEMOD_ERROR_WAIT;
error = 0xd4;
}
break;
case DEMOD_SOF_COMPLETE:
case DEMOD_MANCHESTER_D:
case DEMOD_MANCHESTER_E:
// OPPOSITE FROM ISO14443 - 11110000 = 0 (1 in 14443)
// 00001111 = 1 (0 in 14443)
if (Demod.sub == SUB_SECOND_HALF) { // SUB_FIRST_HALF
Demod.bitCount++;
Demod.shiftReg = (Demod.shiftReg >> 1) ^ 0x100;
Demod.state = DEMOD_MANCHESTER_D;
} else if (Demod.sub == SUB_FIRST_HALF) { // SUB_SECOND_HALF
Demod.bitCount++;
Demod.shiftReg >>= 1;
Demod.state = DEMOD_MANCHESTER_E;
} else if (Demod.sub == SUB_BOTH) {
Demod.state = DEMOD_MANCHESTER_F;
} else {
Demod.state = DEMOD_ERROR_WAIT;
error = 0x55;
}
break;
case DEMOD_MANCHESTER_F:
// Tag response does not need to be a complete byte!
if (Demod.len > 0 || Demod.bitCount > 0) {
if (Demod.bitCount > 1) { // was > 0, do not interpret last closing bit, is part of EOF
Demod.shiftReg >>= (9 - Demod.bitCount); // right align data
Demod.output[Demod.len] = Demod.shiftReg & 0xff;
Demod.len++;
}
Demod.state = DEMOD_UNSYNCD;
return true;
} else {
Demod.output[Demod.len] = 0xad;
Demod.state = DEMOD_ERROR_WAIT;
error = 0x03;
}
break;
case DEMOD_ERROR_WAIT:
Demod.state = DEMOD_UNSYNCD;
break;
default:
Demod.output[Demod.len] = 0xdd;
Demod.state = DEMOD_UNSYNCD;
break;
}
if (Demod.bitCount >= 8) {
Demod.shiftReg >>= 1;
Demod.output[Demod.len] = (Demod.shiftReg & 0xff);
Demod.len++;
Demod.bitCount = 0;
Demod.shiftReg = 0;
}
if (error) {
uart_debug(error, bit);
return true;
}
return false;
}
//=============================================================================
// Finally, a `sniffer' for iClass communication
// Both sides of communication!
//=============================================================================
static void iclass_setup_sniff(void) {
if (MF_DBGLEVEL > 3) Dbprintf("iclass_setup_sniff Enter");
LEDsoff();
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
// connect Demodulated Signal to ADC:
SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
// Set up the synchronous serial port
FpgaSetupSsc();
BigBuf_free();
BigBuf_Clear_ext(false);
clear_trace();
set_tracing(true);
// Initialize Demod and Uart structs
DemodInit(BigBuf_malloc(ICLASS_BUFFER_SIZE));
uart_init(BigBuf_malloc(ICLASS_BUFFER_SIZE));
//UartInit(BigBuf_malloc(ICLASS_BUFFER_SIZE));
if (MF_DBGLEVEL > 1) {
// Print debug information about the buffer sizes
Dbprintf("[+] Sniffing buffers initialized:");
Dbprintf(" Trace: %i bytes", BigBuf_max_traceLen());
Dbprintf(" Reader -> tag: %i bytes", ICLASS_BUFFER_SIZE);
Dbprintf(" tag -> Reader: %i bytes", ICLASS_BUFFER_SIZE);
Dbprintf(" DMA: %i bytes", ICLASS_DMA_BUFFER_SIZE);
}
// Set FPGA in the appropriate mode
// put the FPGA in the appropriate mode
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_SNIFFER);
SpinDelay(200);
// Start the SSP timer
StartCountSspClk();
LED_A_ON();
if (MF_DBGLEVEL > 3) Dbprintf("[+] iclass_setup_sniff Exit");
}
//-----------------------------------------------------------------------------
// Record the sequence of commands sent by the reader to the tag, with
// triggering so that we start recording at the point that the tag is moved
// near the reader.
//-----------------------------------------------------------------------------
// turn off afterwards
void RAMFUNC SniffIClass(void) {
//int datalen = 0;
uint32_t previous_data = 0;
uint32_t time_0 = 0, time_start = 0, time_stop = 0;
uint32_t sniffCounter = 0;
bool TagIsActive = false;
bool ReaderIsActive = false;
iclass_setup_sniff();
// The DMA buffer, used to stream samples from the FPGA
// *dmaBuf is the start reference.
uint8_t *dmaBuf = BigBuf_malloc(ICLASS_DMA_BUFFER_SIZE);
// pointer to samples from fpga
uint8_t *data = dmaBuf;
// Setup and start DMA.
if (!FpgaSetupSscDma(dmaBuf, ICLASS_DMA_BUFFER_SIZE)) {
if (MF_DBGLEVEL > 1) DbpString("[-] FpgaSetupSscDma failed. Exiting");
return;
}
// time ZERO, the point from which it all is calculated.
time_0 = GetCountSspClk();
int div = 0;
uint8_t tag_byte = 0, foo = 0;
// loop and listen
// every sample (1byte in data),
// contains HIGH nibble = reader data
// contains LOW nibble = tag data
// so two bytes are needed in order to get 1byte of either reader or tag data. (ie 2 sample bytes)
// since reader data is manchester encoded, we need 2bytes of data in order to get one demoded byte. (ie: 4 sample bytes)
while (!BUTTON_PRESS()) {
WDT_HIT();
previous_data <<= 8;
previous_data |= *data;
sniffCounter++;
data++;
if (data == dmaBuf + ICLASS_DMA_BUFFER_SIZE) {
data = dmaBuf;
AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
AT91C_BASE_PDC_SSC->PDC_RNCR = ICLASS_DMA_BUFFER_SIZE;
}
if (*data & 0xF) {
//tag_byte <<= 1;
tag_byte ^= (1 << 4);
foo ^= (1 << (3 - div));
Dbprintf(" %d|%x == %d|%x", tag_byte, tag_byte, foo, foo);
}
div++;
// every odd sample
if (sniffCounter & 0x01) {
// no need to try decoding reader data if the tag is sending
// READER TO CARD
if (!TagIsActive) {
LED_C_INV();
// HIGH nibble is always reader data.
uint8_t reader_byte = (previous_data & 0xF0) | (*data >> 4);
uart_samples(reader_byte);
if (Uart.frame_done) {
time_stop = GetCountSspClk() - time_0;
LogTrace(Uart.buf, Uart.len, time_start, time_stop, NULL, true);
DemodReset();
uart_reset();
} else {
time_start = GetCountSspClk() - time_0;
}
ReaderIsActive = Uart.frame_done;
}
}
// every four sample
if ((sniffCounter % 4) == 0) {
// need two samples to feed Manchester
// no need to try decoding tag data if the reader is sending - and we cannot afford the time
// CARD TO READER
if (!ReaderIsActive) {
LED_C_INV();
// LOW nibble is always tag data.
/*
uint32_t tag_byte =
((previous_data & 0x0F000000) >> 8 ) |
((previous_data & 0x000F0000) >> 4 ) |
((previous_data & 0x00000F00) ) |
((previous_data & 0x0000000F) << 4 ) |
(*data & 0xF);
*/
//uint8_t tag_byte = ((previous_data & 0xF) << 4 ) | (*data & 0xF);
if (ManchesterDecoding_iclass(foo)) {
time_stop = GetCountSspClk() - time_0;
LogTrace(Demod.output, Demod.len, time_start, time_stop, NULL, false);
DemodReset();
uart_reset();
} else {
time_start = GetCountSspClk() - time_0;
}
TagIsActive = (Demod.state != DEMOD_UNSYNCD);
}
tag_byte = 0;
foo = 0;
div = 0;
}
} // end main loop
if (MF_DBGLEVEL >= 1) {
DbpString("[+] Sniff statistics:");
Dbhexdump(ICLASS_DMA_BUFFER_SIZE, data, false);
}
switch_off();
}
void rotateCSN(uint8_t *originalCSN, uint8_t *rotatedCSN) {
int i;
for (i = 0; i < 8; i++)
rotatedCSN[i] = (originalCSN[i] >> 3) | (originalCSN[(i + 1) % 8] << 5);
}
//-----------------------------------------------------------------------------
// SIMULATION
// Wait for commands from reader
// Stop when button is pressed
// Or return TRUE when command is captured
//-----------------------------------------------------------------------------
static bool GetIClassCommandFromReader(uint8_t *received, int *len, int maxLen) {
// Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
// only, since we are receiving, not transmitting).
// Signal field is off with the appropriate LED
LED_D_OFF();
uart_init(received);
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
// clear RXRDY:
uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
while (!BUTTON_PRESS()) {
WDT_HIT();