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proxmark3/armsrc/iso14443a.c
martin.holst@gmail.com 3be2a5ae0b reverted a non-intended commit with crappy debug printouts
2014-02-05 18:53:55 +00:00

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//-----------------------------------------------------------------------------
// Merlok - June 2011, 2012
// Gerhard de Koning Gans - May 2008
// Hagen Fritsch - June 2010
//
// 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 14443 type A.
//-----------------------------------------------------------------------------
#include "proxmark3.h"
#include "apps.h"
#include "util.h"
#include "string.h"
#include "cmd.h"
#include "iso14443crc.h"
#include "iso14443a.h"
#include "crapto1.h"
#include "mifareutil.h"
static uint32_t iso14a_timeout;
uint8_t *trace = (uint8_t *) BigBuf+TRACE_OFFSET;
int traceLen = 0;
int rsamples = 0;
int tracing = TRUE;
uint8_t trigger = 0;
// the block number for the ISO14443-4 PCB
static uint8_t iso14_pcb_blocknum = 0;
// CARD TO READER - manchester
// Sequence D: 11110000 modulation with subcarrier during first half
// Sequence E: 00001111 modulation with subcarrier during second half
// Sequence F: 00000000 no modulation with subcarrier
// READER TO CARD - miller
// Sequence X: 00001100 drop after half a period
// Sequence Y: 00000000 no drop
// Sequence Z: 11000000 drop at start
#define SEC_D 0xf0
#define SEC_E 0x0f
#define SEC_F 0x00
#define SEC_X 0x0c
#define SEC_Y 0x00
#define SEC_Z 0xc0
const uint8_t OddByteParity[256] = {
1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1
};
void iso14a_set_trigger(bool enable) {
trigger = enable;
}
void iso14a_clear_trace() {
memset(trace, 0x44, TRACE_SIZE);
traceLen = 0;
}
void iso14a_set_tracing(bool enable) {
tracing = enable;
}
void iso14a_set_timeout(uint32_t timeout) {
iso14a_timeout = timeout;
}
//-----------------------------------------------------------------------------
// Generate the parity value for a byte sequence
//
//-----------------------------------------------------------------------------
byte_t oddparity (const byte_t bt)
{
return OddByteParity[bt];
}
uint32_t GetParity(const uint8_t * pbtCmd, int iLen)
{
int i;
uint32_t dwPar = 0;
// Generate the parity bits
for (i = 0; i < iLen; i++) {
// and save them to a 32Bit word
dwPar |= ((OddByteParity[pbtCmd[i]]) << i);
}
return dwPar;
}
void AppendCrc14443a(uint8_t* data, int len)
{
ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1);
}
// The function LogTrace() is also used by the iClass implementation in iClass.c
int RAMFUNC LogTrace(const uint8_t * btBytes, int iLen, int iSamples, uint32_t dwParity, int bReader)
{
// Return when trace is full
if (traceLen >= TRACE_SIZE) return FALSE;
// Trace the random, i'm curious
rsamples += iSamples;
trace[traceLen++] = ((rsamples >> 0) & 0xff);
trace[traceLen++] = ((rsamples >> 8) & 0xff);
trace[traceLen++] = ((rsamples >> 16) & 0xff);
trace[traceLen++] = ((rsamples >> 24) & 0xff);
if (!bReader) {
trace[traceLen - 1] |= 0x80;
}
trace[traceLen++] = ((dwParity >> 0) & 0xff);
trace[traceLen++] = ((dwParity >> 8) & 0xff);
trace[traceLen++] = ((dwParity >> 16) & 0xff);
trace[traceLen++] = ((dwParity >> 24) & 0xff);
trace[traceLen++] = iLen;
memcpy(trace + traceLen, btBytes, iLen);
traceLen += iLen;
return TRUE;
}
//-----------------------------------------------------------------------------
// The software UART that receives commands from the reader, and its state
// variables.
//-----------------------------------------------------------------------------
static tUart Uart;
static RAMFUNC int MillerDecoding(int bit)
{
//int error = 0;
int bitright;
if(!Uart.bitBuffer) {
Uart.bitBuffer = bit ^ 0xFF0;
return FALSE;
}
else {
Uart.bitBuffer <<= 4;
Uart.bitBuffer ^= bit;
}
int EOC = FALSE;
if(Uart.state != STATE_UNSYNCD) {
Uart.posCnt++;
if((Uart.bitBuffer & Uart.syncBit) ^ Uart.syncBit) {
bit = 0x00;
}
else {
bit = 0x01;
}
if(((Uart.bitBuffer << 1) & Uart.syncBit) ^ Uart.syncBit) {
bitright = 0x00;
}
else {
bitright = 0x01;
}
if(bit != bitright) { bit = bitright; }
if(Uart.posCnt == 1) {
// measurement first half bitperiod
if(!bit) {
Uart.drop = DROP_FIRST_HALF;
}
}
else {
// measurement second half bitperiod
if(!bit & (Uart.drop == DROP_NONE)) {
Uart.drop = DROP_SECOND_HALF;
}
else if(!bit) {
// measured a drop in first and second half
// which should not be possible
Uart.state = STATE_ERROR_WAIT;
//error = 0x01;
}
Uart.posCnt = 0;
switch(Uart.state) {
case STATE_START_OF_COMMUNICATION:
Uart.shiftReg = 0;
if(Uart.drop == DROP_SECOND_HALF) {
// error, should not happen in SOC
Uart.state = STATE_ERROR_WAIT;
//error = 0x02;
}
else {
// correct SOC
Uart.state = STATE_MILLER_Z;
}
break;
case STATE_MILLER_Z:
Uart.bitCnt++;
Uart.shiftReg >>= 1;
if(Uart.drop == DROP_NONE) {
// logic '0' followed by sequence Y
// end of communication
Uart.state = STATE_UNSYNCD;
EOC = TRUE;
}
// if(Uart.drop == DROP_FIRST_HALF) {
// Uart.state = STATE_MILLER_Z; stay the same
// we see a logic '0' }
if(Uart.drop == DROP_SECOND_HALF) {
// we see a logic '1'
Uart.shiftReg |= 0x100;
Uart.state = STATE_MILLER_X;
}
break;
case STATE_MILLER_X:
Uart.shiftReg >>= 1;
if(Uart.drop == DROP_NONE) {
// sequence Y, we see a '0'
Uart.state = STATE_MILLER_Y;
Uart.bitCnt++;
}
if(Uart.drop == DROP_FIRST_HALF) {
// Would be STATE_MILLER_Z
// but Z does not follow X, so error
Uart.state = STATE_ERROR_WAIT;
//error = 0x03;
}
if(Uart.drop == DROP_SECOND_HALF) {
// We see a '1' and stay in state X
Uart.shiftReg |= 0x100;
Uart.bitCnt++;
}
break;
case STATE_MILLER_Y:
Uart.bitCnt++;
Uart.shiftReg >>= 1;
if(Uart.drop == DROP_NONE) {
// logic '0' followed by sequence Y
// end of communication
Uart.state = STATE_UNSYNCD;
EOC = TRUE;
}
if(Uart.drop == DROP_FIRST_HALF) {
// we see a '0'
Uart.state = STATE_MILLER_Z;
}
if(Uart.drop == DROP_SECOND_HALF) {
// We see a '1' and go to state X
Uart.shiftReg |= 0x100;
Uart.state = STATE_MILLER_X;
}
break;
case STATE_ERROR_WAIT:
// That went wrong. Now wait for at least two bit periods
// and try to sync again
if(Uart.drop == DROP_NONE) {
Uart.highCnt = 6;
Uart.state = STATE_UNSYNCD;
}
break;
default:
Uart.state = STATE_UNSYNCD;
Uart.highCnt = 0;
break;
}
Uart.drop = DROP_NONE;
// should have received at least one whole byte...
if((Uart.bitCnt == 2) && EOC && (Uart.byteCnt > 0)) {
return TRUE;
}
if(Uart.bitCnt == 9) {
Uart.output[Uart.byteCnt] = (Uart.shiftReg & 0xff);
Uart.byteCnt++;
Uart.parityBits <<= 1;
Uart.parityBits ^= ((Uart.shiftReg >> 8) & 0x01);
if(EOC) {
// when End of Communication received and
// all data bits processed..
return TRUE;
}
Uart.bitCnt = 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;
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.drop = DROP_FIRST_HALF;
Uart.bitCnt = 0;
Uart.byteCnt = 0;
Uart.parityBits = 0;
//error = 0;
}
else {
Uart.highCnt = 0;
}
}
else {
if(Uart.highCnt < 8) {
Uart.highCnt++;
}
}
}
return FALSE;
}
//=============================================================================
// ISO 14443 Type A - Manchester decoder
//=============================================================================
// Basics:
// The tag will modulate the reader field by asserting different loads to it. As a consequence, the voltage
// at the reader antenna will be modulated as well. The FPGA detects the modulation for us and would deliver e.g. the following:
// ........ 0 0 1 1 1 1 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 .......
// The Manchester decoder needs to identify the following sequences:
// 4 ticks modulated followed by 4 ticks unmodulated: Sequence D = 1 (also used as "start of communication")
// 4 ticks unmodulated followed by 4 ticks modulated: Sequence E = 0
// 8 ticks unmodulated: Sequence F = end of communication
// 8 ticks modulated: A collision. Save the collision position and treat as Sequence D
// Note 1: the bitstream may start at any time (either in first or second nibble within the parameter bit). We therefore need to sync.
// Note 2: parameter offset is used to determine the position of the parity bits (required for the anticollision command only)
static tDemod Demod;
inline RAMFUNC bool IsModulation(byte_t b)
{
if (b >= 5 || b == 3) // majority decision: 2 or more bits are set
return true;
else
return false;
}
inline RAMFUNC bool IsModulationNibble1(byte_t b)
{
return IsModulation((b & 0xE0) >> 5);
}
inline RAMFUNC bool IsModulationNibble2(byte_t b)
{
return IsModulation((b & 0x0E) >> 1);
}
static RAMFUNC int ManchesterDecoding(int bit, uint16_t offset)
{
switch (Demod.state) {
case DEMOD_UNSYNCD: // not yet synced
Demod.len = 0; // initialize number of decoded data bytes
Demod.bitCount = offset; // initialize number of decoded data bits
Demod.shiftReg = 0; // initialize shiftreg to hold decoded data bits
Demod.parityBits = 0; // initialize parity bits
Demod.collisionPos = 0; // Position of collision bit
if (IsModulationNibble1(bit)
&& !IsModulationNibble2(bit)) { // this is the start bit
Demod.samples = 8;
if(trigger) LED_A_OFF();
Demod.state = DEMOD_MANCHESTER_DATA;
} else if (!IsModulationNibble1(bit) && IsModulationNibble2(bit)) { // this may be the first half of the start bit
Demod.samples = 4;
Demod.state = DEMOD_HALF_SYNCD;
}
break;
case DEMOD_HALF_SYNCD:
Demod.samples += 8;
if (IsModulationNibble1(bit)) { // error: this was not a start bit.
Demod.state = DEMOD_UNSYNCD;
} else {
if (IsModulationNibble2(bit)) { // modulation in first half
Demod.state = DEMOD_MOD_FIRST_HALF;
} else { // no modulation in first half
Demod.state = DEMOD_NOMOD_FIRST_HALF;
}
}
break;
case DEMOD_MOD_FIRST_HALF:
Demod.samples += 8;
Demod.bitCount++;
if (IsModulationNibble1(bit)) { // modulation in both halfs - collision
if (!Demod.collisionPos) {
Demod.collisionPos = (Demod.len << 3) + Demod.bitCount;
}
} // modulation in first half only - Sequence D = 1
Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100; // add a 1 to the shiftreg
if(Demod.bitCount >= 9) { // if we decoded a full byte (including parity)
Demod.parityBits <<= 1; // make room for the parity bit
Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
Demod.bitCount = 0;
Demod.shiftReg = 0;
}
if (IsModulationNibble2(bit)) { // modulation in first half
Demod.state = DEMOD_MOD_FIRST_HALF;
} else { // no modulation in first half
Demod.state = DEMOD_NOMOD_FIRST_HALF;
}
break;
case DEMOD_NOMOD_FIRST_HALF:
if (IsModulationNibble1(bit)) { // modulation in second half only - Sequence E = 0
Demod.bitCount++;
Demod.samples += 8;
Demod.shiftReg = (Demod.shiftReg >> 1); // add a 0 to the shiftreg
if(Demod.bitCount >= 9) { // if we decoded a full byte (including parity)
Demod.parityBits <<= 1; // make room for the new parity bit
Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
Demod.bitCount = 0;
Demod.shiftReg = 0;
}
} else { // no modulation in both halves - End of communication
Demod.samples += 4;
if(Demod.bitCount > 0) { // if we decoded bits
Demod.shiftReg >>= (9 - Demod.bitCount); // add the remaining decoded bits to the output
Demod.output[Demod.len++] = Demod.shiftReg & 0xff;
// No parity bit, so just shift a 0
Demod.parityBits <<= 1;
}
Demod.state = DEMOD_UNSYNCD; // start from the beginning
return TRUE; // we are finished with decoding the raw data sequence
}
if (IsModulationNibble2(bit)) { // modulation in first half
Demod.state = DEMOD_MOD_FIRST_HALF;
} else { // no modulation in first half
Demod.state = DEMOD_NOMOD_FIRST_HALF;
}
break;
case DEMOD_MANCHESTER_DATA:
Demod.samples += 8;
if (IsModulationNibble1(bit)) { // modulation in first half
if (IsModulationNibble2(bit) & 0x0f) { // ... and in second half = collision
if (!Demod.collisionPos) {
Demod.collisionPos = (Demod.len << 3) + Demod.bitCount;
}
} // modulation in first half only - Sequence D = 1
Demod.bitCount++;
Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100; // in both cases, add a 1 to the shiftreg
if(Demod.bitCount >= 9) { // if we decoded a full byte (including parity)
Demod.parityBits <<= 1; // make room for the parity bit
Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
Demod.bitCount = 0;
Demod.shiftReg = 0;
}
} else { // no modulation in first half
if (IsModulationNibble2(bit)) { // and modulation in second half = Sequence E = 0
Demod.bitCount++;
Demod.shiftReg = (Demod.shiftReg >> 1); // add a 0 to the shiftreg
if(Demod.bitCount >= 9) { // if we decoded a full byte (including parity)
Demod.parityBits <<= 1; // make room for the new parity bit
Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
Demod.bitCount = 0;
Demod.shiftReg = 0;
}
} else { // no modulation in both halves - End of communication
if(Demod.bitCount > 0) { // if we decoded bits
Demod.shiftReg >>= (9 - Demod.bitCount); // add the remaining decoded bits to the output
Demod.output[Demod.len++] = Demod.shiftReg & 0xff;
// No parity bit, so just shift a 0
Demod.parityBits <<= 1;
}
Demod.state = DEMOD_UNSYNCD; // start from the beginning
return TRUE; // we are finished with decoding the raw data sequence
}
}
}
return FALSE; // not finished yet, need more data
}
//=============================================================================
// Finally, a `sniffer' for ISO 14443 Type A
// Both sides of communication!
//=============================================================================
//-----------------------------------------------------------------------------
// 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.
//-----------------------------------------------------------------------------
void RAMFUNC SnoopIso14443a(uint8_t param) {
// param:
// bit 0 - trigger from first card answer
// bit 1 - trigger from first reader 7-bit request
LEDsoff();
// init trace buffer
iso14a_clear_trace();
// We won't start recording the frames that we acquire until we trigger;
// a good trigger condition to get started is probably when we see a
// response from the tag.
// triggered == FALSE -- to wait first for card
int triggered = !(param & 0x03);
// The command (reader -> tag) that we're receiving.
// The length of a received command will in most cases be no more than 18 bytes.
// So 32 should be enough!
uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
// The response (tag -> reader) that we're receiving.
uint8_t *receivedResponse = (((uint8_t *)BigBuf) + RECV_RES_OFFSET);
// As we receive stuff, we copy it from receivedCmd or receivedResponse
// into trace, along with its length and other annotations.
//uint8_t *trace = (uint8_t *)BigBuf;
// The DMA buffer, used to stream samples from the FPGA
int8_t *dmaBuf = ((int8_t *)BigBuf) + DMA_BUFFER_OFFSET;
int8_t *data = dmaBuf;
int maxDataLen = 0;
int dataLen = 0;
// Set up the demodulator for tag -> reader responses.
Demod.output = receivedResponse;
Demod.len = 0;
Demod.state = DEMOD_UNSYNCD;
// Set up the demodulator for the reader -> tag commands
memset(&Uart, 0, sizeof(Uart));
Uart.output = receivedCmd;
Uart.byteCntMax = 32; // was 100 (greg)//////////////////
Uart.state = STATE_UNSYNCD;
// Setup for the DMA.
FpgaSetupSsc();
FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
// And put the FPGA in the appropriate mode
// Signal field is off with the appropriate LED
LED_D_OFF();
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_SNIFFER);
SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
// Count of samples received so far, so that we can include timing
// information in the trace buffer.
rsamples = 0;
// And now we loop, receiving samples.
while(true) {
if(BUTTON_PRESS()) {
DbpString("cancelled by button");
goto done;
}
LED_A_ON();
WDT_HIT();
int register readBufDataP = data - dmaBuf;
int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR;
if (readBufDataP <= dmaBufDataP){
dataLen = dmaBufDataP - readBufDataP;
} else {
dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP + 1;
}
// test for length of buffer
if(dataLen > maxDataLen) {
maxDataLen = dataLen;
if(dataLen > 400) {
Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
goto done;
}
}
if(dataLen < 1) continue;
// primary buffer was stopped( <-- we lost data!
if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
}
// secondary buffer sets as primary, secondary buffer was stopped
if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
}
LED_A_OFF();
rsamples += 4;
if(MillerDecoding((data[0] & 0xF0) >> 4)) {
LED_C_ON();
// check - if there is a short 7bit request from reader
if ((!triggered) && (param & 0x02) && (Uart.byteCnt == 1) && (Uart.bitCnt = 9)) triggered = TRUE;
if(triggered) {
if (!LogTrace(receivedCmd, Uart.byteCnt, 0 - Uart.samples, Uart.parityBits, TRUE)) break;
}
/* And ready to receive another command. */
Uart.state = STATE_UNSYNCD;
/* And also reset the demod code, which might have been */
/* false-triggered by the commands from the reader. */
Demod.state = DEMOD_UNSYNCD;
LED_B_OFF();
}
if(ManchesterDecoding(data[0], 0)) {
LED_B_ON();
if (!LogTrace(receivedResponse, Demod.len, 0 - Demod.samples, Demod.parityBits, FALSE)) break;
if ((!triggered) && (param & 0x01)) triggered = TRUE;
// And ready to receive another response.
memset(&Demod, 0, sizeof(Demod));
Demod.output = receivedResponse;
Demod.state = DEMOD_UNSYNCD;
LED_C_OFF();
}
data++;
if(data > dmaBuf + DMA_BUFFER_SIZE) {
data = dmaBuf;
}
} // main cycle
DbpString("COMMAND FINISHED");
done:
AT91C_BASE_PDC_SSC->PDC_PTCR = AT91C_PDC_RXTDIS;
Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.byteCnt=%x", maxDataLen, Uart.state, Uart.byteCnt);
Dbprintf("Uart.byteCntMax=%x, traceLen=%x, Uart.output[0]=%08x", Uart.byteCntMax, traceLen, (int)Uart.output[0]);
LEDsoff();
}
//-----------------------------------------------------------------------------
// Prepare tag messages
//-----------------------------------------------------------------------------
static void CodeIso14443aAsTagPar(const uint8_t *cmd, int len, uint32_t dwParity)
{
int i;
ToSendReset();
// Correction bit, might be removed when not needed
ToSendStuffBit(0);
ToSendStuffBit(0);
ToSendStuffBit(0);
ToSendStuffBit(0);
ToSendStuffBit(1); // 1
ToSendStuffBit(0);
ToSendStuffBit(0);
ToSendStuffBit(0);
// Send startbit
ToSend[++ToSendMax] = SEC_D;
for(i = 0; i < len; i++) {
int j;
uint8_t b = cmd[i];
// Data bits
for(j = 0; j < 8; j++) {
if(b & 1) {
ToSend[++ToSendMax] = SEC_D;
} else {
ToSend[++ToSendMax] = SEC_E;
}
b >>= 1;
}
// Get the parity bit
if ((dwParity >> i) & 0x01) {
ToSend[++ToSendMax] = SEC_D;
} else {
ToSend[++ToSendMax] = SEC_E;
}
}
// Send stopbit
ToSend[++ToSendMax] = SEC_F;
// Convert from last byte pos to length
ToSendMax++;
}
static void CodeIso14443aAsTag(const uint8_t *cmd, int len){
CodeIso14443aAsTagPar(cmd, len, GetParity(cmd, len));
}
////-----------------------------------------------------------------------------
//// This is to send a NACK kind of answer, its only 3 bits, I know it should be 4
////-----------------------------------------------------------------------------
//static void CodeStrangeAnswerAsTag()
//{
// int i;
//
// ToSendReset();
//
// // Correction bit, might be removed when not needed
// ToSendStuffBit(0);
// ToSendStuffBit(0);
// ToSendStuffBit(0);
// ToSendStuffBit(0);
// ToSendStuffBit(1); // 1
// ToSendStuffBit(0);
// ToSendStuffBit(0);
// ToSendStuffBit(0);
//
// // Send startbit
// ToSend[++ToSendMax] = SEC_D;
//
// // 0
// ToSend[++ToSendMax] = SEC_E;
//
// // 0
// ToSend[++ToSendMax] = SEC_E;
//
// // 1
// ToSend[++ToSendMax] = SEC_D;
//
// // Send stopbit
// ToSend[++ToSendMax] = SEC_F;
//
// // Flush the buffer in FPGA!!
// for(i = 0; i < 5; i++) {
// ToSend[++ToSendMax] = SEC_F;
// }
//
// // Convert from last byte pos to length
// ToSendMax++;
//}
static void Code4bitAnswerAsTag(uint8_t cmd)
{
int i;
ToSendReset();
// Correction bit, might be removed when not needed
ToSendStuffBit(0);
ToSendStuffBit(0);
ToSendStuffBit(0);
ToSendStuffBit(0);
ToSendStuffBit(1); // 1
ToSendStuffBit(0);
ToSendStuffBit(0);
ToSendStuffBit(0);
// Send startbit
ToSend[++ToSendMax] = SEC_D;
uint8_t b = cmd;
for(i = 0; i < 4; i++) {
if(b & 1) {
ToSend[++ToSendMax] = SEC_D;
} else {
ToSend[++ToSendMax] = SEC_E;
}
b >>= 1;
}
// Send stopbit
ToSend[++ToSendMax] = SEC_F;
// Flush the buffer in FPGA!!
for(i = 0; i < 5; i++) {
ToSend[++ToSendMax] = SEC_F;
}
// Convert from last byte pos to length
ToSendMax++;
}
//-----------------------------------------------------------------------------
// Wait for commands from reader
// Stop when button is pressed
// Or return TRUE when command is captured
//-----------------------------------------------------------------------------
static int GetIso14443aCommandFromReader(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();
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
// Now run a `software UART' on the stream of incoming samples.
Uart.output = received;
Uart.byteCntMax = maxLen;
Uart.state = STATE_UNSYNCD;
for(;;) {
WDT_HIT();
if(BUTTON_PRESS()) return FALSE;
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
AT91C_BASE_SSC->SSC_THR = 0x00;
}
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
if(MillerDecoding((b & 0xf0) >> 4)) {
*len = Uart.byteCnt;
return TRUE;
}
if(MillerDecoding(b & 0x0f)) {
*len = Uart.byteCnt;
return TRUE;
}
}
}
}
static int EmSendCmd14443aRaw(uint8_t *resp, int respLen, int correctionNeeded);
int EmSend4bitEx(uint8_t resp, int correctionNeeded);
int EmSend4bit(uint8_t resp);
int EmSendCmdExPar(uint8_t *resp, int respLen, int correctionNeeded, uint32_t par);
int EmSendCmdExPar(uint8_t *resp, int respLen, int correctionNeeded, uint32_t par);
int EmSendCmdEx(uint8_t *resp, int respLen, int correctionNeeded);
int EmSendCmd(uint8_t *resp, int respLen);
int EmSendCmdPar(uint8_t *resp, int respLen, uint32_t par);
static uint8_t* free_buffer_pointer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
typedef struct {
uint8_t* response;
size_t response_n;
uint8_t* modulation;
size_t modulation_n;
} tag_response_info_t;
void reset_free_buffer() {
free_buffer_pointer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
}
bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) {
// Exmaple response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes
// This will need the following byte array for a modulation sequence
// 144 data bits (18 * 8)
// 18 parity bits
// 2 Start and stop
// 1 Correction bit (Answer in 1172 or 1236 periods, see FPGA)
// 1 just for the case
// ----------- +
// 166 bytes, since every bit that needs to be send costs us a byte
//
// Prepare the tag modulation bits from the message
CodeIso14443aAsTag(response_info->response,response_info->response_n);
// Make sure we do not exceed the free buffer space
if (ToSendMax > max_buffer_size) {
Dbprintf("Out of memory, when modulating bits for tag answer:");
Dbhexdump(response_info->response_n,response_info->response,false);
return false;
}
// Copy the byte array, used for this modulation to the buffer position
memcpy(response_info->modulation,ToSend,ToSendMax);
// Store the number of bytes that were used for encoding/modulation
response_info->modulation_n = ToSendMax;
return true;
}
bool prepare_allocated_tag_modulation(tag_response_info_t* response_info) {
// Retrieve and store the current buffer index
response_info->modulation = free_buffer_pointer;
// Determine the maximum size we can use from our buffer
size_t max_buffer_size = (((uint8_t *)BigBuf)+FREE_BUFFER_OFFSET+FREE_BUFFER_SIZE)-free_buffer_pointer;
// Forward the prepare tag modulation function to the inner function
if (prepare_tag_modulation(response_info,max_buffer_size)) {
// Update the free buffer offset
free_buffer_pointer += ToSendMax;
return true;
} else {
return false;
}
}
//-----------------------------------------------------------------------------
// Main loop of simulated tag: receive commands from reader, decide what
// response to send, and send it.
//-----------------------------------------------------------------------------
void SimulateIso14443aTag(int tagType, int uid_1st, int uid_2nd, byte_t* data)
{
// Enable and clear the trace
tracing = TRUE;
iso14a_clear_trace();
// This function contains the tag emulation
uint8_t sak;
// The first response contains the ATQA (note: bytes are transmitted in reverse order).
uint8_t response1[2];
switch (tagType) {
case 1: { // MIFARE Classic
// Says: I am Mifare 1k - original line
response1[0] = 0x04;
response1[1] = 0x00;
sak = 0x08;
} break;
case 2: { // MIFARE Ultralight
// Says: I am a stupid memory tag, no crypto
response1[0] = 0x04;
response1[1] = 0x00;
sak = 0x00;
} break;
case 3: { // MIFARE DESFire
// Says: I am a DESFire tag, ph33r me
response1[0] = 0x04;
response1[1] = 0x03;
sak = 0x20;
} break;
case 4: { // ISO/IEC 14443-4
// Says: I am a javacard (JCOP)
response1[0] = 0x04;
response1[1] = 0x00;
sak = 0x28;
} break;
default: {
Dbprintf("Error: unkown tagtype (%d)",tagType);
return;
} break;
}
// The second response contains the (mandatory) first 24 bits of the UID
uint8_t response2[5];
// Check if the uid uses the (optional) part
uint8_t response2a[5];
if (uid_2nd) {
response2[0] = 0x88;
num_to_bytes(uid_1st,3,response2+1);
num_to_bytes(uid_2nd,4,response2a);
response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3];
// Configure the ATQA and SAK accordingly
response1[0] |= 0x40;
sak |= 0x04;
} else {
num_to_bytes(uid_1st,4,response2);
// Configure the ATQA and SAK accordingly
response1[0] &= 0xBF;
sak &= 0xFB;
}
// Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID.
response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3];
// Prepare the mandatory SAK (for 4 and 7 byte UID)
uint8_t response3[3];
response3[0] = sak;
ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
// Prepare the optional second SAK (for 7 byte UID), drop the cascade bit
uint8_t response3a[3];
response3a[0] = sak & 0xFB;
ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
uint8_t response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce
uint8_t response6[] = { 0x04, 0x58, 0x00, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS
ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]);
#define TAG_RESPONSE_COUNT 7
tag_response_info_t responses[TAG_RESPONSE_COUNT] = {
{ .response = response1, .response_n = sizeof(response1) }, // Answer to request - respond with card type
{ .response = response2, .response_n = sizeof(response2) }, // Anticollision cascade1 - respond with uid
{ .response = response2a, .response_n = sizeof(response2a) }, // Anticollision cascade2 - respond with 2nd half of uid if asked
{ .response = response3, .response_n = sizeof(response3) }, // Acknowledge select - cascade 1
{ .response = response3a, .response_n = sizeof(response3a) }, // Acknowledge select - cascade 2
{ .response = response5, .response_n = sizeof(response5) }, // Authentication answer (random nonce)
{ .response = response6, .response_n = sizeof(response6) }, // dummy ATS (pseudo-ATR), answer to RATS
};
// Allocate 512 bytes for the dynamic modulation, created when the reader querries for it
// Such a response is less time critical, so we can prepare them on the fly
#define DYNAMIC_RESPONSE_BUFFER_SIZE 64
#define DYNAMIC_MODULATION_BUFFER_SIZE 512
uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
tag_response_info_t dynamic_response_info = {
.response = dynamic_response_buffer,
.response_n = 0,
.modulation = dynamic_modulation_buffer,
.modulation_n = 0
};
// Reset the offset pointer of the free buffer
reset_free_buffer();
// Prepare the responses of the anticollision phase
// there will be not enough time to do this at the moment the reader sends it REQA
for (size_t i=0; i<TAG_RESPONSE_COUNT; i++) {
prepare_allocated_tag_modulation(&responses[i]);
}
uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
int len;
// To control where we are in the protocol
int order = 0;
int lastorder;
// Just to allow some checks
int happened = 0;
int happened2 = 0;
int cmdsRecvd = 0;
// We need to listen to the high-frequency, peak-detected path.
SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
FpgaSetupSsc();
cmdsRecvd = 0;
tag_response_info_t* p_response;
LED_A_ON();
for(;;) {
// Clean receive command buffer
memset(receivedCmd, 0x44, RECV_CMD_SIZE);
if(!GetIso14443aCommandFromReader(receivedCmd, &len, RECV_CMD_SIZE)) {
DbpString("Button press");
break;
}
if (tracing) {
LogTrace(receivedCmd,len, 0, Uart.parityBits, TRUE);
}
p_response = NULL;
// doob - added loads of debug strings so we can see what the reader is saying to us during the sim as hi14alist is not populated
// Okay, look at the command now.
lastorder = order;
if(receivedCmd[0] == 0x26) { // Received a REQUEST
p_response = &responses[0]; order = 1;
} else if(receivedCmd[0] == 0x52) { // Received a WAKEUP
p_response = &responses[0]; order = 6;
} else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) { // Received request for UID (cascade 1)
p_response = &responses[1]; order = 2;
} else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x95) { // Received request for UID (cascade 2)
p_response = &responses[2]; order = 20;
} else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x93) { // Received a SELECT (cascade 1)
p_response = &responses[3]; order = 3;
} else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x95) { // Received a SELECT (cascade 2)
p_response = &responses[4]; order = 30;
} else if(receivedCmd[0] == 0x30) { // Received a (plain) READ
EmSendCmdEx(data+(4*receivedCmd[0]),16,false);
Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
// We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
p_response = NULL;
} else if(receivedCmd[0] == 0x50) { // Received a HALT
// DbpString("Reader requested we HALT!:");
p_response = NULL;
} else if(receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61) { // Received an authentication request
p_response = &responses[5]; order = 7;
} else if(receivedCmd[0] == 0xE0) { // Received a RATS request
p_response = &responses[6]; order = 70;
} else if (order == 7 && len ==8) { // Received authentication request
uint32_t nr = bytes_to_num(receivedCmd,4);
uint32_t ar = bytes_to_num(receivedCmd+4,4);
Dbprintf("Auth attempt {nr}{ar}: %08x %08x",nr,ar);
} else {
// Check for ISO 14443A-4 compliant commands, look at left nibble
switch (receivedCmd[0]) {
case 0x0B:
case 0x0A: { // IBlock (command)
dynamic_response_info.response[0] = receivedCmd[0];
dynamic_response_info.response[1] = 0x00;
dynamic_response_info.response[2] = 0x90;
dynamic_response_info.response[3] = 0x00;
dynamic_response_info.response_n = 4;
} break;
case 0x1A:
case 0x1B: { // Chaining command
dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1);
dynamic_response_info.response_n = 2;
} break;
case 0xaa:
case 0xbb: {
dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11;
dynamic_response_info.response_n = 2;
} break;
case 0xBA: { //
memcpy(dynamic_response_info.response,"\xAB\x00",2);
dynamic_response_info.response_n = 2;
} break;
case 0xCA:
case 0xC2: { // Readers sends deselect command
memcpy(dynamic_response_info.response,"\xCA\x00",2);
dynamic_response_info.response_n = 2;
} break;
default: {
// Never seen this command before
Dbprintf("Received unknown command (len=%d):",len);
Dbhexdump(len,receivedCmd,false);
// Do not respond
dynamic_response_info.response_n = 0;
} break;
}
if (dynamic_response_info.response_n > 0) {
// Copy the CID from the reader query
dynamic_response_info.response[1] = receivedCmd[1];
// Add CRC bytes, always used in ISO 14443A-4 compliant cards
AppendCrc14443a(dynamic_response_info.response,dynamic_response_info.response_n);
dynamic_response_info.response_n += 2;
if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) {
Dbprintf("Error preparing tag response");
break;
}
p_response = &dynamic_response_info;
}
}
// Count number of wakeups received after a halt
if(order == 6 && lastorder == 5) { happened++; }
// Count number of other messages after a halt
if(order != 6 && lastorder == 5) { happened2++; }
// Look at last parity bit to determine timing of answer
if((Uart.parityBits & 0x01) || receivedCmd[0] == 0x52) {
// 1236, so correction bit needed
//i = 0;
}
if(cmdsRecvd > 999) {
DbpString("1000 commands later...");
break;
}
cmdsRecvd++;
if (p_response != NULL) {
EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52);
if (tracing) {
LogTrace(p_response->response,p_response->response_n,0,SwapBits(GetParity(p_response->response,p_response->response_n),p_response->response_n),FALSE);
if(traceLen > TRACE_SIZE) {
DbpString("Trace full");
// break;
}
}
}
}
Dbprintf("%x %x %x", happened, happened2, cmdsRecvd);
LED_A_OFF();
}
// prepare a delayed transfer. This simply shifts ToSend[] by a number
// of bits specified in the delay parameter.
void PrepareDelayedTransfer(uint16_t delay)
{
uint8_t bitmask = 0;
uint8_t bits_to_shift = 0;
uint8_t bits_shifted = 0;
delay &= 0x07;
if (delay) {
for (uint16_t i = 0; i < delay; i++) {
bitmask |= (0x01 << i);
}
ToSend[++ToSendMax] = 0x00;
for (uint16_t i = 0; i < ToSendMax; i++) {
bits_to_shift = ToSend[i] & bitmask;
ToSend[i] = ToSend[i] >> delay;
ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay));
bits_shifted = bits_to_shift;
}
}
}
//-----------------------------------------------------------------------------
// Transmit the command (to the tag) that was placed in ToSend[].
// Parameter timing:
// if NULL: ignored
// if == 0: return time of transfer
// if != 0: delay transfer until time specified
//-----------------------------------------------------------------------------
static void TransmitFor14443a(const uint8_t *cmd, int len, uint32_t *timing)
{
int c;
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
if (timing) {
if(*timing == 0) { // Measure time
*timing = (GetCountMifare() + 8) & 0xfffffff8;
} else {
PrepareDelayedTransfer(*timing & 0x00000007); // Delay transfer (fine tuning - up to 7 MF clock ticks)
}
if(MF_DBGLEVEL >= 4 && GetCountMifare() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
while(GetCountMifare() < (*timing & 0xfffffff8)); // Delay transfer (multiple of 8 MF clock ticks)
}
for(c = 0; c < 10;) { // standard delay for each transfer (allow tag to be ready after last transmission?)
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
AT91C_BASE_SSC->SSC_THR = 0x00;
c++;
}
}
c = 0;
for(;;) {
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
AT91C_BASE_SSC->SSC_THR = cmd[c];
c++;
if(c >= len) {
break;
}
}
}
}
//-----------------------------------------------------------------------------
// Prepare reader command (in bits, support short frames) to send to FPGA
//-----------------------------------------------------------------------------
void CodeIso14443aBitsAsReaderPar(const uint8_t * cmd, int bits, uint32_t dwParity)
{
int i, j;
int last;
uint8_t b;
ToSendReset();
// Start of Communication (Seq. Z)
ToSend[++ToSendMax] = SEC_Z;
last = 0;
size_t bytecount = nbytes(bits);
// Generate send structure for the data bits
for (i = 0; i < bytecount; i++) {
// Get the current byte to send
b = cmd[i];
size_t bitsleft = MIN((bits-(i*8)),8);
for (j = 0; j < bitsleft; j++) {
if (b & 1) {
// Sequence X
ToSend[++ToSendMax] = SEC_X;
last = 1;
} else {
if (last == 0) {
// Sequence Z
ToSend[++ToSendMax] = SEC_Z;
} else {
// Sequence Y
ToSend[++ToSendMax] = SEC_Y;
last = 0;
}
}
b >>= 1;
}
// Only transmit (last) parity bit if we transmitted a complete byte
if (j == 8) {
// Get the parity bit
if ((dwParity >> i) & 0x01) {
// Sequence X
ToSend[++ToSendMax] = SEC_X;
last = 1;
} else {
if (last == 0) {
// Sequence Z
ToSend[++ToSendMax] = SEC_Z;
} else {
// Sequence Y
ToSend[++ToSendMax] = SEC_Y;
last = 0;
}
}
}
}
// End of Communication
if (last == 0) {
// Sequence Z
ToSend[++ToSendMax] = SEC_Z;
} else {
// Sequence Y
ToSend[++ToSendMax] = SEC_Y;
last = 0;
}
// Sequence Y
ToSend[++ToSendMax] = SEC_Y;
// Just to be sure!
ToSend[++ToSendMax] = SEC_Y;
ToSend[++ToSendMax] = SEC_Y;
ToSend[++ToSendMax] = SEC_Y;
// Convert from last character reference to length
ToSendMax++;
}
//-----------------------------------------------------------------------------
// Prepare reader command to send to FPGA
//-----------------------------------------------------------------------------
void CodeIso14443aAsReaderPar(const uint8_t * cmd, int len, uint32_t dwParity)
{
CodeIso14443aBitsAsReaderPar(cmd,len*8,dwParity);
}
//-----------------------------------------------------------------------------
// Wait for commands from reader
// Stop when button is pressed (return 1) or field was gone (return 2)
// Or return 0 when command is captured
//-----------------------------------------------------------------------------
static int EmGetCmd(uint8_t *received, int *len, int maxLen)
{
*len = 0;
uint32_t timer = 0, vtime = 0;
int analogCnt = 0;
int analogAVG = 0;
// 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();
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
// Set ADC to read field strength
AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST;
AT91C_BASE_ADC->ADC_MR =
ADC_MODE_PRESCALE(32) |
ADC_MODE_STARTUP_TIME(16) |
ADC_MODE_SAMPLE_HOLD_TIME(8);
AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF);
// start ADC
AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
// Now run a 'software UART' on the stream of incoming samples.
Uart.output = received;
Uart.byteCntMax = maxLen;
Uart.state = STATE_UNSYNCD;
for(;;) {
WDT_HIT();
if (BUTTON_PRESS()) return 1;
// test if the field exists
if (AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ADC_CHAN_HF)) {
analogCnt++;
analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF];
AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
if (analogCnt >= 32) {
if ((33000 * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) {
vtime = GetTickCount();
if (!timer) timer = vtime;
// 50ms no field --> card to idle state
if (vtime - timer > 50) return 2;
} else
if (timer) timer = 0;
analogCnt = 0;
analogAVG = 0;
}
}
// transmit none
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
AT91C_BASE_SSC->SSC_THR = 0x00;
}
// receive and test the miller decoding
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
volatile uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
if(MillerDecoding((b & 0xf0) >> 4)) {
*len = Uart.byteCnt;
if (tracing) LogTrace(received, *len, GetDeltaCountUS(), Uart.parityBits, TRUE);
return 0;
}
if(MillerDecoding(b & 0x0f)) {
*len = Uart.byteCnt;
if (tracing) LogTrace(received, *len, GetDeltaCountUS(), Uart.parityBits, TRUE);
return 0;
}
}
}
}
static int EmSendCmd14443aRaw(uint8_t *resp, int respLen, int correctionNeeded)
{
int i, u = 0;
uint8_t b = 0;
// Modulate Manchester
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
AT91C_BASE_SSC->SSC_THR = 0x00;
FpgaSetupSsc();
// include correction bit
i = 1;
if((Uart.parityBits & 0x01) || correctionNeeded) {
// 1236, so correction bit needed
i = 0;
}
// send cycle
for(;;) {
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
volatile uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
(void)b;
}
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
if(i > respLen) {
b = 0xff; // was 0x00
u++;
} else {
b = resp[i];
i++;
}
AT91C_BASE_SSC->SSC_THR = b;
if(u > 4) break;
}
if(BUTTON_PRESS()) {
break;
}
}
return 0;
}
int EmSend4bitEx(uint8_t resp, int correctionNeeded){
Code4bitAnswerAsTag(resp);
int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
if (tracing) LogTrace(&resp, 1, GetDeltaCountUS(), GetParity(&resp, 1), FALSE);
return res;
}
int EmSend4bit(uint8_t resp){
return EmSend4bitEx(resp, 0);
}
int EmSendCmdExPar(uint8_t *resp, int respLen, int correctionNeeded, uint32_t par){
CodeIso14443aAsTagPar(resp, respLen, par);
int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
if (tracing) LogTrace(resp, respLen, GetDeltaCountUS(), par, FALSE);
return res;
}
int EmSendCmdEx(uint8_t *resp, int respLen, int correctionNeeded){
return EmSendCmdExPar(resp, respLen, correctionNeeded, GetParity(resp, respLen));
}
int EmSendCmd(uint8_t *resp, int respLen){
return EmSendCmdExPar(resp, respLen, 0, GetParity(resp, respLen));
}
int EmSendCmdPar(uint8_t *resp, int respLen, uint32_t par){
return EmSendCmdExPar(resp, respLen, 0, par);
}
//-----------------------------------------------------------------------------
// Wait a certain time for tag response
// If a response is captured return TRUE
// If it takes too long return FALSE
//-----------------------------------------------------------------------------
static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint16_t offset, int maxLen, int *samples)
{
int c;
// Set FPGA mode to "reader listen mode", no modulation (listen
// only, since we are receiving, not transmitting).
// Signal field is on with the appropriate LED
LED_D_ON();
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
// Now get the answer from the card
Demod.output = receivedResponse;
Demod.len = 0;
Demod.state = DEMOD_UNSYNCD;
uint8_t b;
c = 0;
for(;;) {
WDT_HIT();
// if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
// AT91C_BASE_SSC->SSC_THR = 0x00; // To make use of exact timing of next command from reader!!
// if (elapsed) (*elapsed)++;
// }
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
if(c < iso14a_timeout) { c++; } else { return FALSE; }
b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
if(ManchesterDecoding(b, offset)) {
*samples = Demod.samples;
return TRUE;
}
}
}
}
void ReaderTransmitBitsPar(uint8_t* frame, int bits, uint32_t par, uint32_t *timing)
{
CodeIso14443aBitsAsReaderPar(frame,bits,par);
// Send command to tag
TransmitFor14443a(ToSend, ToSendMax, timing);
if(trigger)
LED_A_ON();
// Log reader command in trace buffer
if (tracing) LogTrace(frame,nbytes(bits),0,par,TRUE);
}
void ReaderTransmitPar(uint8_t* frame, int len, uint32_t par, uint32_t *timing)
{
ReaderTransmitBitsPar(frame,len*8,par, timing);
}
void ReaderTransmitBits(uint8_t* frame, int len, uint32_t *timing)
{
// Generate parity and redirect
ReaderTransmitBitsPar(frame,len,GetParity(frame,len/8), timing);
}
void ReaderTransmit(uint8_t* frame, int len, uint32_t *timing)
{
// Generate parity and redirect
ReaderTransmitBitsPar(frame,len*8,GetParity(frame,len), timing);
}
int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset)
{
int samples = 0;
if (!GetIso14443aAnswerFromTag(receivedAnswer,offset,160,&samples)) return FALSE;
if (tracing) LogTrace(receivedAnswer,Demod.len,samples,Demod.parityBits,FALSE);
if(samples == 0) return FALSE;
return Demod.len;
}
int ReaderReceive(uint8_t* receivedAnswer)
{
return ReaderReceiveOffset(receivedAnswer, 0);
}
int ReaderReceivePar(uint8_t *receivedAnswer, uint32_t *parptr)
{
int samples = 0;
if (!GetIso14443aAnswerFromTag(receivedAnswer,0,160,&samples)) return FALSE;
if (tracing) LogTrace(receivedAnswer,Demod.len,samples,Demod.parityBits,FALSE);
*parptr = Demod.parityBits;
if(samples == 0) return FALSE;
return Demod.len;
}
/* performs iso14443a anticollision procedure
* fills the uid pointer unless NULL
* fills resp_data unless NULL */
int iso14443a_select_card(byte_t* uid_ptr, iso14a_card_select_t* p_hi14a_card, uint32_t* cuid_ptr) {
uint8_t wupa[] = { 0x52 }; // 0x26 - REQA 0x52 - WAKE-UP
uint8_t sel_all[] = { 0x93,0x20 };
uint8_t sel_uid[] = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
uint8_t rats[] = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
uint8_t* resp = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET); // was 3560 - tied to other size changes
byte_t uid_resp[4];
size_t uid_resp_len;
uint8_t sak = 0x04; // cascade uid
int cascade_level = 0;
int len;
// Broadcast for a card, WUPA (0x52) will force response from all cards in the field
ReaderTransmitBitsPar(wupa,7,0, NULL);
// Receive the ATQA
if(!ReaderReceive(resp)) return 0;
// Dbprintf("atqa: %02x %02x",resp[0],resp[1]);
if(p_hi14a_card) {
memcpy(p_hi14a_card->atqa, resp, 2);
p_hi14a_card->uidlen = 0;
memset(p_hi14a_card->uid,0,10);
}
// clear uid
if (uid_ptr) {
memset(uid_ptr,0,10);
}
// OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
// which case we need to make a cascade 2 request and select - this is a long UID
// While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
for(; sak & 0x04; cascade_level++) {
// SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
// SELECT_ALL
ReaderTransmit(sel_all,sizeof(sel_all), NULL);
if (!ReaderReceive(resp)) return 0;
if (Demod.collisionPos) { // we had a collision and need to construct the UID bit by bit
memset(uid_resp, 0, 4);
uint16_t uid_resp_bits = 0;
uint16_t collision_answer_offset = 0;
// anti-collision-loop:
while (Demod.collisionPos) {
Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos);
for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) { // add valid UID bits before collision point
uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01;
uid_resp[uid_resp_bits & 0xf8] |= UIDbit << (uid_resp_bits % 8);
}
uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8); // next time select the card(s) with a 1 in the collision position
uid_resp_bits++;
// construct anticollosion command:
sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07); // length of data in bytes and bits
for (uint16_t i = 0; i <= uid_resp_bits/8; i++) {
sel_uid[2+i] = uid_resp[i];
}
collision_answer_offset = uid_resp_bits%8;
ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL);
if (!ReaderReceiveOffset(resp, collision_answer_offset)) return 0;
}
// finally, add the last bits and BCC of the UID
for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) {
uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01;
uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8);
}
} else { // no collision, use the response to SELECT_ALL as current uid
memcpy(uid_resp,resp,4);
}
uid_resp_len = 4;
// Dbprintf("uid: %02x %02x %02x %02x",uid_resp[0],uid_resp[1],uid_resp[2],uid_resp[3]);
// calculate crypto UID. Always use last 4 Bytes.
if(cuid_ptr) {
*cuid_ptr = bytes_to_num(uid_resp, 4);
}
// Construct SELECT UID command
sel_uid[1] = 0x70; // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC)
memcpy(sel_uid+2,uid_resp,4); // the UID
sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5]; // calculate and add BCC
AppendCrc14443a(sel_uid,7); // calculate and add CRC
ReaderTransmit(sel_uid,sizeof(sel_uid), NULL);
// Receive the SAK
if (!ReaderReceive(resp)) return 0;
sak = resp[0];
// Test if more parts of the uid are comming
if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) {
// Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of:
// http://www.nxp.com/documents/application_note/AN10927.pdf
memcpy(uid_resp, uid_resp + 1, 3);
uid_resp_len = 3;
}
if(uid_ptr) {
memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len);
}
if(p_hi14a_card) {
memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
p_hi14a_card->uidlen += uid_resp_len;
}
}
if(p_hi14a_card) {
p_hi14a_card->sak = sak;
p_hi14a_card->ats_len = 0;
}
if( (sak & 0x20) == 0) {
return 2; // non iso14443a compliant tag
}
// Request for answer to select
AppendCrc14443a(rats, 2);
ReaderTransmit(rats, sizeof(rats), NULL);
if (!(len = ReaderReceive(resp))) return 0;
if(p_hi14a_card) {
memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
p_hi14a_card->ats_len = len;
}
// reset the PCB block number
iso14_pcb_blocknum = 0;
return 1;
}
void iso14443a_setup() {
// Set up the synchronous serial port
FpgaSetupSsc();
// Start from off (no field generated)
// Signal field is off with the appropriate LED
// LED_D_OFF();
// FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
// SpinDelay(50);
SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
// Now give it time to spin up.
// Signal field is on with the appropriate LED
LED_D_ON();
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
SpinDelay(7); // iso14443-3 specifies 5ms max.
Demod.state = DEMOD_UNSYNCD;
iso14a_timeout = 2048; //default
}
int iso14_apdu(uint8_t * cmd, size_t cmd_len, void * data) {
uint8_t real_cmd[cmd_len+4];
real_cmd[0] = 0x0a; //I-Block
// put block number into the PCB
real_cmd[0] |= iso14_pcb_blocknum;
real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards
memcpy(real_cmd+2, cmd, cmd_len);
AppendCrc14443a(real_cmd,cmd_len+2);
ReaderTransmit(real_cmd, cmd_len+4, NULL);
size_t len = ReaderReceive(data);
uint8_t * data_bytes = (uint8_t *) data;
if (!len)
return 0; //DATA LINK ERROR
// if we received an I- or R(ACK)-Block with a block number equal to the
// current block number, toggle the current block number
else if (len >= 4 // PCB+CID+CRC = 4 bytes
&& ((data_bytes[0] & 0xC0) == 0 // I-Block
|| (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0
&& (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers
{
iso14_pcb_blocknum ^= 1;
}
return len;
}
//-----------------------------------------------------------------------------
// Read an ISO 14443a tag. Send out commands and store answers.
//
//-----------------------------------------------------------------------------
void ReaderIso14443a(UsbCommand * c)
{
iso14a_command_t param = c->arg[0];
uint8_t * cmd = c->d.asBytes;
size_t len = c->arg[1];
size_t lenbits = c->arg[2];
uint32_t arg0 = 0;
byte_t buf[USB_CMD_DATA_SIZE];
if(param & ISO14A_CONNECT) {
iso14a_clear_trace();
}
iso14a_set_tracing(true);
if(param & ISO14A_REQUEST_TRIGGER) {
iso14a_set_trigger(1);
}
if(param & ISO14A_CONNECT) {
iso14443a_setup();
if(!(param & ISO14A_NO_SELECT)) {
iso14a_card_select_t *card = (iso14a_card_select_t*)buf;
arg0 = iso14443a_select_card(NULL,card,NULL);
cmd_send(CMD_ACK,arg0,card->uidlen,0,buf,sizeof(iso14a_card_select_t));
}
}
if(param & ISO14A_SET_TIMEOUT) {
iso14a_timeout = c->arg[2];
}
if(param & ISO14A_SET_TIMEOUT) {
iso14a_timeout = c->arg[2];
}
if(param & ISO14A_APDU) {
arg0 = iso14_apdu(cmd, len, buf);
cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
}
if(param & ISO14A_RAW) {
if(param & ISO14A_APPEND_CRC) {
AppendCrc14443a(cmd,len);
len += 2;
}
if(lenbits>0) {
ReaderTransmitBitsPar(cmd,lenbits,GetParity(cmd,lenbits/8), NULL);
} else {
ReaderTransmit(cmd,len, NULL);
}
arg0 = ReaderReceive(buf);
cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
}
if(param & ISO14A_REQUEST_TRIGGER) {
iso14a_set_trigger(0);
}
if(param & ISO14A_NO_DISCONNECT) {
return;
}
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
LEDsoff();
}
// Determine the distance between two nonces.
// Assume that the difference is small, but we don't know which is first.
// Therefore try in alternating directions.
int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
uint16_t i;
uint32_t nttmp1, nttmp2;
if (nt1 == nt2) return 0;
nttmp1 = nt1;
nttmp2 = nt2;
for (i = 1; i < 32768; i++) {
nttmp1 = prng_successor(nttmp1, 1);
if (nttmp1 == nt2) return i;
nttmp2 = prng_successor(nttmp2, 1);
if (nttmp2 == nt1) return -i;
}
return(-99999); // either nt1 or nt2 are invalid nonces
}
//-----------------------------------------------------------------------------
// Recover several bits of the cypher stream. This implements (first stages of)
// the algorithm described in "The Dark Side of Security by Obscurity and
// Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime"
// (article by Nicolas T. Courtois, 2009)
//-----------------------------------------------------------------------------
void ReaderMifare(bool first_try)
{
// Mifare AUTH
uint8_t mf_auth[] = { 0x60,0x00,0xf5,0x7b };
uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
static uint8_t mf_nr_ar3;
uint8_t* receivedAnswer = (((uint8_t *)BigBuf) + FREE_BUFFER_OFFSET);
iso14a_clear_trace();
tracing = false;
byte_t nt_diff = 0;
byte_t par = 0;
//byte_t par_mask = 0xff;
static byte_t par_low = 0;
bool led_on = TRUE;
uint8_t uid[10];
uint32_t cuid;
uint32_t nt, previous_nt;
static uint32_t nt_attacked = 0;
byte_t par_list[8] = {0,0,0,0,0,0,0,0};
byte_t ks_list[8] = {0,0,0,0,0,0,0,0};
static uint32_t sync_time;
static uint32_t sync_cycles;
int catch_up_cycles = 0;
int last_catch_up = 0;
uint16_t consecutive_resyncs = 0;
int isOK = 0;
if (first_try) {
StartCountMifare();
mf_nr_ar3 = 0;
iso14443a_setup();
while((GetCountMifare() & 0xffff0000) != 0x10000); // wait for counter to reset and "warm up"
sync_time = GetCountMifare() & 0xfffffff8;
sync_cycles = 65536; // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
nt_attacked = 0;
nt = 0;
par = 0;
}
else {
// we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same)
// nt_attacked = prng_successor(nt_attacked, 1);
mf_nr_ar3++;
mf_nr_ar[3] = mf_nr_ar3;
par = par_low;
}
LED_A_ON();
LED_B_OFF();
LED_C_OFF();
for(uint16_t i = 0; TRUE; i++) {
WDT_HIT();
// Test if the action was cancelled
if(BUTTON_PRESS()) {
break;
}
LED_C_ON();
if(!iso14443a_select_card(uid, NULL, &cuid)) {
if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card");
continue;
}
//keep the card active
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
catch_up_cycles = 0;
// if we missed the sync time already, advance to the next nonce repeat
while(GetCountMifare() > sync_time) {
sync_time = (sync_time & 0xfffffff8) + sync_cycles;
}
// Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked)
ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
// Receive the (4 Byte) "random" nonce
if (!ReaderReceive(receivedAnswer)) {
if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Couldn't receive tag nonce");
continue;
}
previous_nt = nt;
nt = bytes_to_num(receivedAnswer, 4);
// Transmit reader nonce with fake par
ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
if (first_try && previous_nt && !nt_attacked) { // we didn't calibrate our clock yet
int nt_distance = dist_nt(previous_nt, nt);
if (nt_distance == 0) {
nt_attacked = nt;
}
else {
if (nt_distance == -99999) { // invalid nonce received, try again
continue;
}
sync_cycles = (sync_cycles - nt_distance);
if (MF_DBGLEVEL >= 3) Dbprintf("calibrating in cycle %d. nt_distance=%d, Sync_cycles: %d\n", i, nt_distance, sync_cycles);
continue;
}
}
if ((nt != nt_attacked) && nt_attacked) { // we somehow lost sync. Try to catch up again...
catch_up_cycles = -dist_nt(nt_attacked, nt);
if (catch_up_cycles == 99999) { // invalid nonce received. Don't resync on that one.
catch_up_cycles = 0;
continue;
}
if (catch_up_cycles == last_catch_up) {
consecutive_resyncs++;
}
else {
last_catch_up = catch_up_cycles;
consecutive_resyncs = 0;
}
if (consecutive_resyncs < 3) {
if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d. nt_distance=%d. Consecutive Resyncs = %d. Trying one time catch up...\n", i, -catch_up_cycles, consecutive_resyncs);
}
else {
sync_cycles = sync_cycles + catch_up_cycles;
if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d for the fourth time consecutively (nt_distance = %d). Adjusting sync_cycles to %d.\n", i, -catch_up_cycles, sync_cycles);
}
continue;
}
consecutive_resyncs = 0;
// Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
if (ReaderReceive(receivedAnswer))
{
catch_up_cycles = 8; // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
if (nt_diff == 0)
{
par_low = par & 0x07; // there is no need to check all parities for other nt_diff. Parity Bits for mf_nr_ar[0..2] won't change
}
led_on = !led_on;
if(led_on) LED_B_ON(); else LED_B_OFF();
par_list[nt_diff] = par;
ks_list[nt_diff] = receivedAnswer[0] ^ 0x05;
// Test if the information is complete
if (nt_diff == 0x07) {
isOK = 1;
break;
}
nt_diff = (nt_diff + 1) & 0x07;
mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
par = par_low;
} else {
if (nt_diff == 0 && first_try)
{
par++;
} else {
par = (((par >> 3) + 1) << 3) | par_low;
}
}
}
LogTrace((const uint8_t *)&nt, 4, 0, GetParity((const uint8_t *)&nt, 4), TRUE);
LogTrace(par_list, 8, 0, GetParity(par_list, 8), TRUE);
LogTrace(ks_list, 8, 0, GetParity(ks_list, 8), TRUE);
mf_nr_ar[3] &= 0x1F;
byte_t buf[28];
memcpy(buf + 0, uid, 4);
num_to_bytes(nt, 4, buf + 4);
memcpy(buf + 8, par_list, 8);
memcpy(buf + 16, ks_list, 8);
memcpy(buf + 24, mf_nr_ar, 4);
cmd_send(CMD_ACK,isOK,0,0,buf,28);
// Thats it...
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
LEDsoff();
tracing = TRUE;
}
/**
*MIFARE 1K simulate.
*
*@param flags :
* FLAG_INTERACTIVE - In interactive mode, we are expected to finish the operation with an ACK
* 4B_FLAG_UID_IN_DATA - means that there is a 4-byte UID in the data-section, we're expected to use that
* 7B_FLAG_UID_IN_DATA - means that there is a 7-byte UID in the data-section, we're expected to use that
* FLAG_NR_AR_ATTACK - means we should collect NR_AR responses for bruteforcing later
*@param exitAfterNReads, exit simulation after n blocks have been read, 0 is inifite
*/
void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *datain)
{
int cardSTATE = MFEMUL_NOFIELD;
int _7BUID = 0;
int vHf = 0; // in mV
int res;
uint32_t selTimer = 0;
uint32_t authTimer = 0;
uint32_t par = 0;
int len = 0;
uint8_t cardWRBL = 0;
uint8_t cardAUTHSC = 0;
uint8_t cardAUTHKEY = 0xff; // no authentication
uint32_t cardRr = 0;
uint32_t cuid = 0;
//uint32_t rn_enc = 0;
uint32_t ans = 0;
uint32_t cardINTREG = 0;
uint8_t cardINTBLOCK = 0;
struct Crypto1State mpcs = {0, 0};
struct Crypto1State *pcs;
pcs = &mpcs;
uint32_t numReads = 0;//Counts numer of times reader read a block
uint8_t* receivedCmd = eml_get_bigbufptr_recbuf();
uint8_t *response = eml_get_bigbufptr_sendbuf();
uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID
uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; // !!!
uint8_t rSAK[] = {0x08, 0xb6, 0xdd};
uint8_t rSAK1[] = {0x04, 0xda, 0x17};
uint8_t rAUTH_NT[] = {0x01, 0x02, 0x03, 0x04};
uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
//Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2
// This can be used in a reader-only attack.
// (it can also be retrieved via 'hf 14a list', but hey...
uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0};
uint8_t ar_nr_collected = 0;
// clear trace
iso14a_clear_trace();
tracing = true;
// Authenticate response - nonce
uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
//-- Determine the UID
// Can be set from emulator memory, incoming data
// and can be 7 or 4 bytes long
if(flags & FLAG_4B_UID_IN_DATA)
{
// 4B uid comes from data-portion of packet
memcpy(rUIDBCC1,datain,4);
rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
}else if(flags & FLAG_7B_UID_IN_DATA)
{
// 7B uid comes from data-portion of packet
memcpy(&rUIDBCC1[1],datain,3);
memcpy(rUIDBCC2, datain+3, 4);
_7BUID = true;
}
else
{
// get UID from emul memory
emlGetMemBt(receivedCmd, 7, 1);
_7BUID = !(receivedCmd[0] == 0x00);
if (!_7BUID) { // ---------- 4BUID
emlGetMemBt(rUIDBCC1, 0, 4);
} else { // ---------- 7BUID
emlGetMemBt(&rUIDBCC1[1], 0, 3);
emlGetMemBt(rUIDBCC2, 3, 4);
}
}
/*
* Regardless of what method was used to set the UID, set fifth byte and modify
* the ATQA for 4 or 7-byte UID
*/
rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
if(_7BUID)
{
rATQA[0] = 0x44;
rUIDBCC1[0] = 0x88;
rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
}
// start mkseconds counter
StartCountUS();
// We need to listen to the high-frequency, peak-detected path.
SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
FpgaSetupSsc();
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
SpinDelay(200);
if (MF_DBGLEVEL >= 1) {
if (!_7BUID) {
Dbprintf("4B UID: %02x%02x%02x%02x",rUIDBCC1[0] , rUIDBCC1[1] , rUIDBCC1[2] , rUIDBCC1[3]);
}else
{
Dbprintf("7B UID: (%02x)%02x%02x%02x%02x%02x%02x%02x",rUIDBCC1[0] , rUIDBCC1[1] , rUIDBCC1[2] , rUIDBCC1[3],rUIDBCC2[0],rUIDBCC2[1] ,rUIDBCC2[2] , rUIDBCC2[3]);
}
}
// calibrate mkseconds counter
GetDeltaCountUS();
bool finished = false;
while (!BUTTON_PRESS() && !finished) {
WDT_HIT();
// find reader field
// Vref = 3300mV, and an 10:1 voltage divider on the input
// can measure voltages up to 33000 mV
if (cardSTATE == MFEMUL_NOFIELD) {
vHf = (33000 * AvgAdc(ADC_CHAN_HF)) >> 10;
if (vHf > MF_MINFIELDV) {
cardSTATE_TO_IDLE();
LED_A_ON();
}
}
if(cardSTATE == MFEMUL_NOFIELD) continue;
//Now, get data
res = EmGetCmd(receivedCmd, &len, RECV_CMD_SIZE); // (+ nextCycleTimeout)
if (res == 2) { //Field is off!
cardSTATE = MFEMUL_NOFIELD;
LEDsoff();
continue;
}else if(res == 1) break;//return value 1 means button press
// REQ or WUP request in ANY state and WUP in HALTED state
if (len == 1 && ((receivedCmd[0] == 0x26 && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == 0x52)) {
selTimer = GetTickCount();
EmSendCmdEx(rATQA, sizeof(rATQA), (receivedCmd[0] == 0x52));
cardSTATE = MFEMUL_SELECT1;
// init crypto block
LED_B_OFF();
LED_C_OFF();
crypto1_destroy(pcs);
cardAUTHKEY = 0xff;
continue;
}
switch (cardSTATE) {
case MFEMUL_NOFIELD:
case MFEMUL_HALTED:
case MFEMUL_IDLE:{
break;
}
case MFEMUL_SELECT1:{
// select all
if (len == 2 && (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x20)) {
if (MF_DBGLEVEL >= 4) Dbprintf("SELECT ALL received");
EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1));
break;
}
if (MF_DBGLEVEL >= 4 && len == 9 && receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 )
{
Dbprintf("SELECT %02x%02x%02x%02x received",receivedCmd[2],receivedCmd[3],receivedCmd[4],receivedCmd[5]);
}
// select card
if (len == 9 &&
(receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
if (!_7BUID)
EmSendCmd(rSAK, sizeof(rSAK));
else
EmSendCmd(rSAK1, sizeof(rSAK1));
cuid = bytes_to_num(rUIDBCC1, 4);
if (!_7BUID) {
cardSTATE = MFEMUL_WORK;
LED_B_ON();
if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol1 time: %d", GetTickCount() - selTimer);
break;
} else {
cardSTATE = MFEMUL_SELECT2;
break;
}
}
break;
}
case MFEMUL_AUTH1:{
if( len != 8)
{
cardSTATE_TO_IDLE();
break;
}
uint32_t ar = bytes_to_num(receivedCmd, 4);
uint32_t nr= bytes_to_num(&receivedCmd[4], 4);
//Collect AR/NR
if(ar_nr_collected < 2){
if(ar_nr_responses[2] != ar)
{// Avoid duplicates... probably not necessary, ar should vary.
ar_nr_responses[ar_nr_collected*4] = cuid;
ar_nr_responses[ar_nr_collected*4+1] = nonce;
ar_nr_responses[ar_nr_collected*4+2] = ar;
ar_nr_responses[ar_nr_collected*4+3] = nr;
ar_nr_collected++;
}
}
// --- crypto
crypto1_word(pcs, ar , 1);
cardRr = nr ^ crypto1_word(pcs, 0, 0);
// test if auth OK
if (cardRr != prng_successor(nonce, 64)){
if (MF_DBGLEVEL >= 2) Dbprintf("AUTH FAILED. cardRr=%08x, succ=%08x",cardRr, prng_successor(nonce, 64));
//Shouldn't we respond anything here?
// Right now, we don't nack or anything, which causes the
// reader to do a WUPA after a while. /Martin
cardSTATE_TO_IDLE();
break;
}
ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0);
num_to_bytes(ans, 4, rAUTH_AT);
// --- crypto
EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
LED_C_ON();
cardSTATE = MFEMUL_WORK;
if (MF_DBGLEVEL >= 4) Dbprintf("AUTH COMPLETED. sector=%d, key=%d time=%d", cardAUTHSC, cardAUTHKEY, GetTickCount() - authTimer);
break;
}
case MFEMUL_SELECT2:{
if (!len) break;
if (len == 2 && (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x20)) {
EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2));
break;
}
// select 2 card
if (len == 9 &&
(receivedCmd[0] == 0x95 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0)) {
EmSendCmd(rSAK, sizeof(rSAK));
cuid = bytes_to_num(rUIDBCC2, 4);
cardSTATE = MFEMUL_WORK;
LED_B_ON();
if (MF_DBGLEVEL >= 4) Dbprintf("--> WORK. anticol2 time: %d", GetTickCount() - selTimer);
break;
}
// i guess there is a command). go into the work state.
if (len != 4) break;
cardSTATE = MFEMUL_WORK;
//goto lbWORK;
//intentional fall-through to the next case-stmt
}
case MFEMUL_WORK:{
if (len == 0) break;
bool encrypted_data = (cardAUTHKEY != 0xFF) ;
if(encrypted_data)
{
// decrypt seqence
mf_crypto1_decrypt(pcs, receivedCmd, len);
}
if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) {
authTimer = GetTickCount();
cardAUTHSC = receivedCmd[1] / 4; // received block num
cardAUTHKEY = receivedCmd[0] - 0x60;
crypto1_destroy(pcs);//Added by martin
crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
if (!encrypted_data) { // first authentication
if (MF_DBGLEVEL >= 2) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
crypto1_word(pcs, cuid ^ nonce, 0);//Update crypto state
num_to_bytes(nonce, 4, rAUTH_AT); // Send nonce
}
else{ // nested authentication
if (MF_DBGLEVEL >= 2) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0);
num_to_bytes(ans, 4, rAUTH_AT);
}
EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
//Dbprintf("Sending rAUTH %02x%02x%02x%02x", rAUTH_AT[0],rAUTH_AT[1],rAUTH_AT[2],rAUTH_AT[3]);
cardSTATE = MFEMUL_AUTH1;
break;
}
// rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued
// BUT... ACK --> NACK
if (len == 1 && receivedCmd[0] == CARD_ACK) {
EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
break;
}
// rule 12 of 7.5.3. in ISO 14443-4. R(NAK) --> R(ACK)
if (len == 1 && receivedCmd[0] == CARD_NACK_NA) {
EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
break;
}
if(len != 4) break;
if(receivedCmd[0] == 0x30 // read block
|| receivedCmd[0] == 0xA0 // write block
|| receivedCmd[0] == 0xC0
|| receivedCmd[0] == 0xC1
|| receivedCmd[0] == 0xC2 // inc dec restore
|| receivedCmd[0] == 0xB0) // transfer
{
if (receivedCmd[1] >= 16 * 4)
{
EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02) on out of range block: %d (0x%02x), nacking",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
break;
}
if (receivedCmd[1] / 4 != cardAUTHSC)
{
EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate (0x%02) on block (0x%02x) not authenticated for (0x%02x), nacking",receivedCmd[0],receivedCmd[1],cardAUTHSC);
break;
}
}
// read block
if (receivedCmd[0] == 0x30) {
if (MF_DBGLEVEL >= 2) {
Dbprintf("Reader reading block %d (0x%02x)",receivedCmd[1],receivedCmd[1]);
}
emlGetMem(response, receivedCmd[1], 1);
AppendCrc14443a(response, 16);
mf_crypto1_encrypt(pcs, response, 18, &par);
EmSendCmdPar(response, 18, par);
numReads++;
if(exitAfterNReads > 0 && numReads == exitAfterNReads)
{
Dbprintf("%d reads done, exiting", numReads);
finished = true;
}
break;
}
// write block
if (receivedCmd[0] == 0xA0) {
if (MF_DBGLEVEL >= 2) Dbprintf("RECV 0xA0 write block %d (%02x)",receivedCmd[1],receivedCmd[1]);
EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
//nextCycleTimeout = 50;
cardSTATE = MFEMUL_WRITEBL2;
cardWRBL = receivedCmd[1];
break;
}
// increment, decrement, restore
if (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2) {
if (MF_DBGLEVEL >= 2) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
if (emlCheckValBl(receivedCmd[1])) {
if (MF_DBGLEVEL >= 2) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking");
EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
break;
}
EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
if (receivedCmd[0] == 0xC1)
cardSTATE = MFEMUL_INTREG_INC;
if (receivedCmd[0] == 0xC0)
cardSTATE = MFEMUL_INTREG_DEC;
if (receivedCmd[0] == 0xC2)
cardSTATE = MFEMUL_INTREG_REST;
cardWRBL = receivedCmd[1];
break;
}
// transfer
if (receivedCmd[0] == 0xB0) {
if (MF_DBGLEVEL >= 2) Dbprintf("RECV 0x%02x transfer block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
else
EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
break;
}
// halt
if (receivedCmd[0] == 0x50 && receivedCmd[1] == 0x00) {
LED_B_OFF();
LED_C_OFF();
cardSTATE = MFEMUL_HALTED;
if (MF_DBGLEVEL >= 4) Dbprintf("--> HALTED. Selected time: %d ms", GetTickCount() - selTimer);
break;
}
// RATS
if (receivedCmd[0] == 0xe0) {//RATS
EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
break;
}
// command not allowed
if (MF_DBGLEVEL >= 4) Dbprintf("Received command not allowed, nacking");
EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
// case break
break;
}
case MFEMUL_WRITEBL2:{
if (len == 18){
mf_crypto1_decrypt(pcs, receivedCmd, len);
emlSetMem(receivedCmd, cardWRBL, 1);
EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
cardSTATE = MFEMUL_WORK;
break;
} else {
cardSTATE_TO_IDLE();
break;
}
break;
}
case MFEMUL_INTREG_INC:{
mf_crypto1_decrypt(pcs, receivedCmd, len);
memcpy(&ans, receivedCmd, 4);
if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
cardSTATE_TO_IDLE();
break;
}
cardINTREG = cardINTREG + ans;
cardSTATE = MFEMUL_WORK;
break;
}
case MFEMUL_INTREG_DEC:{
mf_crypto1_decrypt(pcs, receivedCmd, len);
memcpy(&ans, receivedCmd, 4);
if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
cardSTATE_TO_IDLE();
break;
}
cardINTREG = cardINTREG - ans;
cardSTATE = MFEMUL_WORK;
break;
}
case MFEMUL_INTREG_REST:{
mf_crypto1_decrypt(pcs, receivedCmd, len);
memcpy(&ans, receivedCmd, 4);
if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
cardSTATE_TO_IDLE();
break;
}
cardSTATE = MFEMUL_WORK;
break;
}
}
}
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
LEDsoff();
// add trace trailer
memset(rAUTH_NT, 0x44, 4);
LogTrace(rAUTH_NT, 4, 0, 0, TRUE);
if(flags & FLAG_INTERACTIVE)// Interactive mode flag, means we need to send ACK
{
//May just aswell send the collected ar_nr in the response aswell
cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,0,0,&ar_nr_responses,ar_nr_collected*4*4);
}
if(flags & FLAG_NR_AR_ATTACK)
{
if(ar_nr_collected > 1)
{
Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
Dbprintf("../tools/mfkey/mfkey32 %08x %08x %08x %08x",
ar_nr_responses[0], // UID
ar_nr_responses[1], //NT
ar_nr_responses[2], //AR1
ar_nr_responses[3], //NR1
ar_nr_responses[6], //AR2
ar_nr_responses[7] //NR2
);
}else
{
Dbprintf("Failed to obtain two AR/NR pairs!");
if(ar_nr_collected >0)
{
Dbprintf("Only got these: UID=%08d, nonce=%08d, AR1=%08d, NR1=%08d",
ar_nr_responses[0], // UID
ar_nr_responses[1], //NT
ar_nr_responses[2], //AR1
ar_nr_responses[3] //NR1
);
}
}
}
if (MF_DBGLEVEL >= 1) Dbprintf("Emulator stopped. Tracing: %d trace length: %d ", tracing, traceLen);
}
//-----------------------------------------------------------------------------
// MIFARE sniffer.
//
//-----------------------------------------------------------------------------
void RAMFUNC SniffMifare(uint8_t param) {
// param:
// bit 0 - trigger from first card answer
// bit 1 - trigger from first reader 7-bit request
// C(red) A(yellow) B(green)
LEDsoff();
// init trace buffer
iso14a_clear_trace();
// The command (reader -> tag) that we're receiving.
// The length of a received command will in most cases be no more than 18 bytes.
// So 32 should be enough!
uint8_t *receivedCmd = (((uint8_t *)BigBuf) + RECV_CMD_OFFSET);
// The response (tag -> reader) that we're receiving.
uint8_t *receivedResponse = (((uint8_t *)BigBuf) + RECV_RES_OFFSET);
// As we receive stuff, we copy it from receivedCmd or receivedResponse
// into trace, along with its length and other annotations.
//uint8_t *trace = (uint8_t *)BigBuf;
// The DMA buffer, used to stream samples from the FPGA
int8_t *dmaBuf = ((int8_t *)BigBuf) + DMA_BUFFER_OFFSET;
int8_t *data = dmaBuf;
int maxDataLen = 0;
int dataLen = 0;
// Set up the demodulator for tag -> reader responses.
Demod.output = receivedResponse;
Demod.len = 0;
Demod.state = DEMOD_UNSYNCD;
// Set up the demodulator for the reader -> tag commands
memset(&Uart, 0, sizeof(Uart));
Uart.output = receivedCmd;
Uart.byteCntMax = 32; // was 100 (greg)//////////////////
Uart.state = STATE_UNSYNCD;
// Setup for the DMA.
FpgaSetupSsc();
FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
// And put the FPGA in the appropriate mode
// Signal field is off with the appropriate LED
LED_D_OFF();
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_SNIFFER);
SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
// init sniffer
MfSniffInit();
int sniffCounter = 0;
// And now we loop, receiving samples.
while(true) {
if(BUTTON_PRESS()) {
DbpString("cancelled by button");
goto done;
}
LED_A_ON();
WDT_HIT();
if (++sniffCounter > 65) {
if (MfSniffSend(2000)) {
FpgaEnableSscDma();
}
sniffCounter = 0;
}
int register readBufDataP = data - dmaBuf;
int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR;
if (readBufDataP <= dmaBufDataP){
dataLen = dmaBufDataP - readBufDataP;
} else {
dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP + 1;
}
// test for length of buffer
if(dataLen > maxDataLen) {
maxDataLen = dataLen;
if(dataLen > 400) {
Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
goto done;
}
}
if(dataLen < 1) continue;
// primary buffer was stopped( <-- we lost data!
if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
}
// secondary buffer sets as primary, secondary buffer was stopped
if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
}
LED_A_OFF();
if(MillerDecoding((data[0] & 0xF0) >> 4)) {
LED_C_INV();
// check - if there is a short 7bit request from reader
if (MfSniffLogic(receivedCmd, Uart.byteCnt, Uart.parityBits, Uart.bitCnt, TRUE)) break;
/* And ready to receive another command. */
Uart.state = STATE_UNSYNCD;
/* And also reset the demod code */
Demod.state = DEMOD_UNSYNCD;
}
if(ManchesterDecoding(data[0], 0)) {
LED_C_INV();
if (MfSniffLogic(receivedResponse, Demod.len, Demod.parityBits, Demod.bitCount, FALSE)) break;
// And ready to receive another response.
memset(&Demod, 0, sizeof(Demod));
Demod.output = receivedResponse;
Demod.state = DEMOD_UNSYNCD;
/* And also reset the uart code */
Uart.state = STATE_UNSYNCD;
}
data++;
if(data > dmaBuf + DMA_BUFFER_SIZE) {
data = dmaBuf;
}
} // main cycle
DbpString("COMMAND FINISHED");
done:
FpgaDisableSscDma();
MfSniffEnd();
Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.byteCnt=%x Uart.byteCntMax=%x", maxDataLen, Uart.state, Uart.byteCnt, Uart.byteCntMax);
LEDsoff();
}
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