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proxmark3/armsrc/iso14443a.c

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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"
#include "BigBuf.h"
#include "parity.h"
static uint32_t iso14a_timeout;
int rsamples = 0;
uint8_t trigger = 0;
// the block number for the ISO14443-4 PCB
static uint8_t iso14_pcb_blocknum = 0;
//
// ISO14443 timing:
//
// minimum time between the start bits of consecutive transfers from reader to tag: 7000 carrier (13.56Mhz) cycles
#define REQUEST_GUARD_TIME (7000/16 + 1)
// minimum time between last modulation of tag and next start bit from reader to tag: 1172 carrier cycles
#define FRAME_DELAY_TIME_PICC_TO_PCD (1172/16 + 1)
// bool LastCommandWasRequest = FALSE;
//
// Total delays including SSC-Transfers between ARM and FPGA. These are in carrier clock cycles (1/13,56MHz)
//
// When the PM acts as reader and is receiving tag data, it takes
// 3 ticks delay in the AD converter
// 16 ticks until the modulation detector completes and sets curbit
// 8 ticks until bit_to_arm is assigned from curbit
// 8*16 ticks for the transfer from FPGA to ARM
// 4*16 ticks until we measure the time
// - 8*16 ticks because we measure the time of the previous transfer
#define DELAY_AIR2ARM_AS_READER (3 + 16 + 8 + 8*16 + 4*16 - 8*16)
// When the PM acts as a reader and is sending, it takes
// 4*16 ticks until we can write data to the sending hold register
// 8*16 ticks until the SHR is transferred to the Sending Shift Register
// 8 ticks until the first transfer starts
// 8 ticks later the FPGA samples the data
// 1 tick to assign mod_sig_coil
#define DELAY_ARM2AIR_AS_READER (4*16 + 8*16 + 8 + 8 + 1)
// When the PM acts as tag and is receiving it takes
// 2 ticks delay in the RF part (for the first falling edge),
// 3 ticks for the A/D conversion,
// 8 ticks on average until the start of the SSC transfer,
// 8 ticks until the SSC samples the first data
// 7*16 ticks to complete the transfer from FPGA to ARM
// 8 ticks until the next ssp_clk rising edge
// 4*16 ticks until we measure the time
// - 8*16 ticks because we measure the time of the previous transfer
#define DELAY_AIR2ARM_AS_TAG (2 + 3 + 8 + 8 + 7*16 + 8 + 4*16 - 8*16)
// The FPGA will report its internal sending delay in
uint16_t FpgaSendQueueDelay;
// the 5 first bits are the number of bits buffered in mod_sig_buf
// the last three bits are the remaining ticks/2 after the mod_sig_buf shift
#define DELAY_FPGA_QUEUE (FpgaSendQueueDelay<<1)
// When the PM acts as tag and is sending, it takes
// 4*16 ticks until we can write data to the sending hold register
// 8*16 ticks until the SHR is transferred to the Sending Shift Register
// 8 ticks until the first transfer starts
// 8 ticks later the FPGA samples the data
// + a varying number of ticks in the FPGA Delay Queue (mod_sig_buf)
// + 1 tick to assign mod_sig_coil
#define DELAY_ARM2AIR_AS_TAG (4*16 + 8*16 + 8 + 8 + DELAY_FPGA_QUEUE + 1)
// When the PM acts as sniffer and is receiving tag data, it takes
// 3 ticks A/D conversion
// 14 ticks to complete the modulation detection
// 8 ticks (on average) until the result is stored in to_arm
// + the delays in transferring data - which is the same for
// sniffing reader and tag data and therefore not relevant
#define DELAY_TAG_AIR2ARM_AS_SNIFFER (3 + 14 + 8)
// When the PM acts as sniffer and is receiving reader data, it takes
// 2 ticks delay in analogue RF receiver (for the falling edge of the
// start bit, which marks the start of the communication)
// 3 ticks A/D conversion
// 8 ticks on average until the data is stored in to_arm.
// + the delays in transferring data - which is the same for
// sniffing reader and tag data and therefore not relevant
#define DELAY_READER_AIR2ARM_AS_SNIFFER (2 + 3 + 8)
//variables used for timing purposes:
//these are in ssp_clk cycles:
static uint32_t NextTransferTime;
static uint32_t LastTimeProxToAirStart;
static uint32_t LastProxToAirDuration;
// 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
void iso14a_set_trigger(bool enable) {
trigger = enable;
}
void iso14a_set_timeout(uint32_t timeout) {
iso14a_timeout = timeout;
if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443A Timeout set to %ld (%dms)", iso14a_timeout, iso14a_timeout / 106);
}
void iso14a_set_ATS_timeout(uint8_t *ats) {
uint8_t tb1;
uint8_t fwi;
uint32_t fwt;
if (ats[0] > 1) { // there is a format byte T0
if ((ats[1] & 0x20) == 0x20) { // there is an interface byte TB(1)
if ((ats[1] & 0x10) == 0x10) // there is an interface byte TA(1) preceding TB(1)
tb1 = ats[3];
else
tb1 = ats[2];
fwi = (tb1 & 0xf0) >> 4; // frame waiting indicator (FWI)
//fwt = 256 * 16 * (1 << fwi); // frame waiting time (FWT) in 1/fc
fwt = 4096 * (1 << fwi);
//iso14a_set_timeout(fwt/(8*16));
iso14a_set_timeout(fwt/128);
}
}
}
//-----------------------------------------------------------------------------
// Generate the parity value for a byte sequence
//
//-----------------------------------------------------------------------------
void GetParity(const uint8_t *pbtCmd, uint16_t iLen, uint8_t *par)
{
uint16_t paritybit_cnt = 0;
uint16_t paritybyte_cnt = 0;
uint8_t parityBits = 0;
for (uint16_t i = 0; i < iLen; i++) {
// Generate the parity bits
parityBits |= ((oddparity8(pbtCmd[i])) << (7-paritybit_cnt));
if (paritybit_cnt == 7) {
par[paritybyte_cnt] = parityBits; // save 8 Bits parity
parityBits = 0; // and advance to next Parity Byte
paritybyte_cnt++;
paritybit_cnt = 0;
} else {
paritybit_cnt++;
}
}
// save remaining parity bits
par[paritybyte_cnt] = parityBits;
}
void AppendCrc14443a(uint8_t* data, int len)
{
ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1);
}
void AppendCrc14443b(uint8_t* data, int len)
{
ComputeCrc14443(CRC_14443_B,data,len,data+len,data+len+1);
}
//=============================================================================
// ISO 14443 Type A - Miller decoder
//=============================================================================
// Basics:
// This decoder is used when the PM3 acts as a tag.
// The reader will generate "pauses" by temporarily switching of the field.
// At the PM3 antenna we will therefore measure a modulated antenna voltage.
// The FPGA does a comparison with a threshold and would deliver e.g.:
// ........ 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1 0 0 1 1 1 1 1 1 1 1 1 1 .......
// The Miller decoder needs to identify the following sequences:
// 2 (or 3) ticks pause followed by 6 (or 5) ticks unmodulated: pause at beginning - Sequence Z ("start of communication" or a "0")
// 8 ticks without a modulation: no pause - Sequence Y (a "0" or "end of communication" or "no information")
// 4 ticks unmodulated followed by 2 (or 3) ticks pause: pause in second half - Sequence X (a "1")
// Note 1: the bitstream may start at any time. We therefore need to sync.
// Note 2: the interpretation of Sequence Y and Z depends on the preceding sequence.
//-----------------------------------------------------------------------------
static tUart Uart;
// Lookup-Table to decide if 4 raw bits are a modulation.
// We accept the following:
// 0001 - a 3 tick wide pause
// 0011 - a 2 tick wide pause, or a three tick wide pause shifted left
// 0111 - a 2 tick wide pause shifted left
// 1001 - a 2 tick wide pause shifted right
const bool Mod_Miller_LUT[] = {
FALSE, TRUE, FALSE, TRUE, FALSE, FALSE, FALSE, TRUE,
FALSE, TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE
};
#define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x000000F0) >> 4])
#define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x0000000F)])
void UartReset()
{
Uart.state = STATE_UNSYNCD;
Uart.bitCount = 0;
Uart.len = 0; // number of decoded data bytes
Uart.parityLen = 0; // number of decoded parity bytes
Uart.shiftReg = 0; // shiftreg to hold decoded data bits
Uart.parityBits = 0; // holds 8 parity bits
Uart.startTime = 0;
Uart.endTime = 0;
Uart.byteCntMax = 0;
Uart.posCnt = 0;
Uart.syncBit = 9999;
}
void UartInit(uint8_t *data, uint8_t *parity)
{
Uart.output = data;
Uart.parity = parity;
Uart.fourBits = 0x00000000; // clear the buffer for 4 Bits
UartReset();
}
// use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
{
Uart.fourBits = (Uart.fourBits << 8) | bit;
if (Uart.state == STATE_UNSYNCD) { // not yet synced
Uart.syncBit = 9999; // not set
// 00x11111 2|3 ticks pause followed by 6|5 ticks unmodulated Sequence Z (a "0" or "start of communication")
// 11111111 8 ticks unmodulation Sequence Y (a "0" or "end of communication" or "no information")
// 111100x1 4 ticks unmodulated followed by 2|3 ticks pause Sequence X (a "1")
// The start bit is one ore more Sequence Y followed by a Sequence Z (... 11111111 00x11111). We need to distinguish from
// Sequence X followed by Sequence Y followed by Sequence Z (111100x1 11111111 00x11111)
// we therefore look for a ...xx1111 11111111 00x11111xxxxxx... pattern
// (12 '1's followed by 2 '0's, eventually followed by another '0', followed by 5 '1's)
//
#define ISO14443A_STARTBIT_MASK 0x07FFEF80 // mask is 00001111 11111111 1110 1111 10000000
#define ISO14443A_STARTBIT_PATTERN 0x07FF8F80 // pattern is 00001111 11111111 1000 1111 10000000
if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 0)) == ISO14443A_STARTBIT_PATTERN >> 0) Uart.syncBit = 7;
else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 1)) == ISO14443A_STARTBIT_PATTERN >> 1) Uart.syncBit = 6;
else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 2)) == ISO14443A_STARTBIT_PATTERN >> 2) Uart.syncBit = 5;
else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 3)) == ISO14443A_STARTBIT_PATTERN >> 3) Uart.syncBit = 4;
else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 4)) == ISO14443A_STARTBIT_PATTERN >> 4) Uart.syncBit = 3;
else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 5)) == ISO14443A_STARTBIT_PATTERN >> 5) Uart.syncBit = 2;
else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 6)) == ISO14443A_STARTBIT_PATTERN >> 6) Uart.syncBit = 1;
else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 7)) == ISO14443A_STARTBIT_PATTERN >> 7) Uart.syncBit = 0;
if (Uart.syncBit != 9999) { // found a sync bit
Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
Uart.startTime -= Uart.syncBit;
Uart.endTime = Uart.startTime;
Uart.state = STATE_START_OF_COMMUNICATION;
}
} else {
if (IsMillerModulationNibble1(Uart.fourBits >> Uart.syncBit)) {
if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) { // Modulation in both halves - error
UartReset();
} else { // Modulation in first half = Sequence Z = logic "0"
if (Uart.state == STATE_MILLER_X) { // error - must not follow after X
UartReset();
} else {
Uart.bitCount++;
Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
Uart.state = STATE_MILLER_Z;
Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 6;
if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
Uart.parityBits <<= 1; // make room for the parity bit
Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
Uart.bitCount = 0;
Uart.shiftReg = 0;
if((Uart.len&0x0007) == 0) { // every 8 data bytes
Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
Uart.parityBits = 0;
}
}
}
}
} else {
if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) { // Modulation second half = Sequence X = logic "1"
Uart.bitCount++;
Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100; // add a 1 to the shiftreg
Uart.state = STATE_MILLER_X;
Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 2;
if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
Uart.parityBits <<= 1; // make room for the new parity bit
Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
Uart.bitCount = 0;
Uart.shiftReg = 0;
if ((Uart.len&0x0007) == 0) { // every 8 data bytes
Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
Uart.parityBits = 0;
}
}
} else { // no modulation in both halves - Sequence Y
if (Uart.state == STATE_MILLER_Z || Uart.state == STATE_MILLER_Y) { // Y after logic "0" - End of Communication
Uart.state = STATE_UNSYNCD;
Uart.bitCount--; // last "0" was part of EOC sequence
Uart.shiftReg <<= 1; // drop it
if(Uart.bitCount > 0) { // if we decoded some bits
Uart.shiftReg >>= (9 - Uart.bitCount); // right align them
Uart.output[Uart.len++] = (Uart.shiftReg & 0xff); // add last byte to the output
Uart.parityBits <<= 1; // add a (void) parity bit
Uart.parityBits <<= (8 - (Uart.len&0x0007)); // left align parity bits
Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store it
return TRUE;
} else if (Uart.len & 0x0007) { // there are some parity bits to store
Uart.parityBits <<= (8 - (Uart.len&0x0007)); // left align remaining parity bits
Uart.parity[Uart.parityLen++] = Uart.parityBits; // and store them
}
if (Uart.len) {
return TRUE; // we are finished with decoding the raw data sequence
} else {
UartReset(); // Nothing received - start over
}
}
if (Uart.state == STATE_START_OF_COMMUNICATION) { // error - must not follow directly after SOC
UartReset();
} else { // a logic "0"
Uart.bitCount++;
Uart.shiftReg = (Uart.shiftReg >> 1); // add a 0 to the shiftreg
Uart.state = STATE_MILLER_Y;
if(Uart.bitCount >= 9) { // if we decoded a full byte (including parity)
Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
Uart.parityBits <<= 1; // make room for the parity bit
Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01); // store parity bit
Uart.bitCount = 0;
Uart.shiftReg = 0;
if ((Uart.len&0x0007) == 0) { // every 8 data bytes
Uart.parity[Uart.parityLen++] = Uart.parityBits; // store 8 parity bits
Uart.parityBits = 0;
}
}
}
}
}
}
return FALSE; // not finished yet, need more data
}
//=============================================================================
// ISO 14443 Type A - Manchester decoder
//=============================================================================
// Basics:
// This decoder is used when the PM3 acts as a reader.
// 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. 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;
// Lookup-Table to decide if 4 raw bits are a modulation.
// We accept three or four "1" in any position
const bool Mod_Manchester_LUT[] = {
FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE,
FALSE, FALSE, FALSE, TRUE, FALSE, TRUE, TRUE, TRUE
};
#define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4])
#define IsManchesterModulationNibble2(b) (Mod_Manchester_LUT[(b & 0x000F)])
void DemodReset()
{
Demod.state = DEMOD_UNSYNCD;
Demod.len = 0; // number of decoded data bytes
Demod.parityLen = 0;
Demod.shiftReg = 0; // shiftreg to hold decoded data bits
Demod.parityBits = 0; //
Demod.collisionPos = 0; // Position of collision bit
Demod.twoBits = 0xffff; // buffer for 2 Bits
Demod.highCnt = 0;
Demod.startTime = 0;
Demod.endTime = 0;
//
Demod.bitCount = 0;
Demod.syncBit = 0xFFFF;
Demod.samples = 0;
}
void DemodInit(uint8_t *data, uint8_t *parity)
{
Demod.output = data;
Demod.parity = parity;
DemodReset();
}
// use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
static RAMFUNC int ManchesterDecoding(uint8_t bit, uint16_t offset, uint32_t non_real_time)
{
Demod.twoBits = (Demod.twoBits << 8) | bit;
if (Demod.state == DEMOD_UNSYNCD) {
if (Demod.highCnt < 2) { // wait for a stable unmodulated signal
if (Demod.twoBits == 0x0000) {
Demod.highCnt++;
} else {
Demod.highCnt = 0;
}
} else {
Demod.syncBit = 0xFFFF; // not set
if ((Demod.twoBits & 0x7700) == 0x7000) Demod.syncBit = 7;
else if ((Demod.twoBits & 0x3B80) == 0x3800) Demod.syncBit = 6;
else if ((Demod.twoBits & 0x1DC0) == 0x1C00) Demod.syncBit = 5;
else if ((Demod.twoBits & 0x0EE0) == 0x0E00) Demod.syncBit = 4;
else if ((Demod.twoBits & 0x0770) == 0x0700) Demod.syncBit = 3;
else if ((Demod.twoBits & 0x03B8) == 0x0380) Demod.syncBit = 2;
else if ((Demod.twoBits & 0x01DC) == 0x01C0) Demod.syncBit = 1;
else if ((Demod.twoBits & 0x00EE) == 0x00E0) Demod.syncBit = 0;
if (Demod.syncBit != 0xFFFF) {
Demod.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
Demod.startTime -= Demod.syncBit;
Demod.bitCount = offset; // number of decoded data bits
Demod.state = DEMOD_MANCHESTER_DATA;
}
}
} else {
if (IsManchesterModulationNibble1(Demod.twoBits >> Demod.syncBit)) { // modulation in first half
if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // ... 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.output[Demod.len++] = (Demod.shiftReg & 0xff);
Demod.parityBits <<= 1; // make room for the parity bit
Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
Demod.bitCount = 0;
Demod.shiftReg = 0;
if((Demod.len&0x0007) == 0) { // every 8 data bytes
Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits
Demod.parityBits = 0;
}
}
Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1) - 4;
} else { // no modulation in first half
if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) { // 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.output[Demod.len++] = (Demod.shiftReg & 0xff);
Demod.parityBits <<= 1; // make room for the new parity bit
Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
Demod.bitCount = 0;
Demod.shiftReg = 0;
if ((Demod.len&0x0007) == 0) { // every 8 data bytes
Demod.parity[Demod.parityLen++] = Demod.parityBits; // store 8 parity bits1
Demod.parityBits = 0;
}
}
Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1);
} else { // no modulation in both halves - End of communication
if(Demod.bitCount > 0) { // there are some remaining data bits
Demod.shiftReg >>= (9 - Demod.bitCount); // right align the decoded bits
Demod.output[Demod.len++] = Demod.shiftReg & 0xff; // and add them to the output
Demod.parityBits <<= 1; // add a (void) parity bit
Demod.parityBits <<= (8 - (Demod.len&0x0007)); // left align remaining parity bits
Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them
return TRUE;
} else if (Demod.len & 0x0007) { // there are some parity bits to store
Demod.parityBits <<= (8 - (Demod.len&0x0007)); // left align remaining parity bits
Demod.parity[Demod.parityLen++] = Demod.parityBits; // and store them
}
if (Demod.len) {
return TRUE; // we are finished with decoding the raw data sequence
} else { // nothing received. Start over
DemodReset();
}
}
}
}
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 SniffIso14443a(uint8_t param) {
// param:
// bit 0 - trigger from first card answer
// bit 1 - trigger from first reader 7-bit request
LEDsoff();
iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
// Allocate memory from BigBuf for some buffers
// free all previous allocations first
BigBuf_free();
// init trace buffer
clear_trace();
set_tracing(TRUE);
// The command (reader -> tag) that we're receiving.
uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
// The response (tag -> reader) that we're receiving.
uint8_t *receivedResponse = BigBuf_malloc(MAX_FRAME_SIZE);
uint8_t *receivedResponsePar = BigBuf_malloc(MAX_PARITY_SIZE);
// The DMA buffer, used to stream samples from the FPGA
uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
uint8_t *data = dmaBuf;
uint8_t previous_data = 0;
int maxDataLen = 0;
int dataLen = 0;
bool TagIsActive = FALSE;
bool ReaderIsActive = FALSE;
// Set up the demodulator for tag -> reader responses.
DemodInit(receivedResponse, receivedResponsePar);
// Set up the demodulator for the reader -> tag commands
UartInit(receivedCmd, receivedCmdPar);
// Setup and start DMA.
FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
// 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
bool triggered = !(param & 0x03);
// And now we loop, receiving samples.
for(uint32_t rsamples = 0; TRUE; ) {
if(BUTTON_PRESS()) {
DbpString("cancelled by button");
break;
}
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;
}
// test for length of buffer
if(dataLen > maxDataLen) {
maxDataLen = dataLen;
if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
Dbprintf("blew circular buffer! dataLen=%d", dataLen);
break;
}
}
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 (rsamples & 0x01) { // Need two samples to feed Miller and Manchester-Decoder
if(!TagIsActive) { // no need to try decoding reader data if the tag is sending
uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
if (MillerDecoding(readerdata, (rsamples-1)*4)) {
LED_C_ON();
// check - if there is a short 7bit request from reader
if ((!triggered) && (param & 0x02) && (Uart.len == 1) && (Uart.bitCount == 7)) triggered = TRUE;
if(triggered) {
if (!LogTrace(receivedCmd,
Uart.len,
Uart.startTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
Uart.parity,
TRUE)) break;
}
/* And ready to receive another command. */
UartReset();
/* And also reset the demod code, which might have been */
/* false-triggered by the commands from the reader. */
DemodReset();
LED_B_OFF();
}
ReaderIsActive = (Uart.state != STATE_UNSYNCD);
}
if(!ReaderIsActive) { // no need to try decoding tag data if the reader is sending - and we cannot afford the time
uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
if(ManchesterDecoding(tagdata, 0, (rsamples-1)*4)) {
LED_B_ON();
if (!LogTrace(receivedResponse,
Demod.len,
Demod.startTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
Demod.endTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
Demod.parity,
FALSE)) break;
if ((!triggered) && (param & 0x01)) triggered = TRUE;
// And ready to receive another response.
DemodReset();
// And reset the Miller decoder including itS (now outdated) input buffer
UartInit(receivedCmd, receivedCmdPar);
LED_C_OFF();
}
TagIsActive = (Demod.state != DEMOD_UNSYNCD);
}
}
previous_data = *data;
rsamples++;
data++;
if(data == dmaBuf + DMA_BUFFER_SIZE) {
data = dmaBuf;
}
} // main cycle
FpgaDisableSscDma();
LEDsoff();
Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len);
Dbprintf("traceLen=%d, Uart.output[0]=%08x", BigBuf_get_traceLen(), (uint32_t)Uart.output[0]);
set_tracing(FALSE);
}
//-----------------------------------------------------------------------------
// Prepare tag messages
//-----------------------------------------------------------------------------
static void CodeIso14443aAsTagPar(const uint8_t *cmd, uint16_t len, uint8_t *parity)
{
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;
LastProxToAirDuration = 8 * ToSendMax - 4;
for(uint16_t i = 0; i < len; i++) {
uint8_t b = cmd[i];
// Data bits
for(uint16_t j = 0; j < 8; j++) {
if(b & 1) {
ToSend[++ToSendMax] = SEC_D;
} else {
ToSend[++ToSendMax] = SEC_E;
}
b >>= 1;
}
// Get the parity bit
if (parity[i>>3] & (0x80>>(i&0x0007))) {
ToSend[++ToSendMax] = SEC_D;
LastProxToAirDuration = 8 * ToSendMax - 4;
} else {
ToSend[++ToSendMax] = SEC_E;
LastProxToAirDuration = 8 * ToSendMax;
}
}
// Send stopbit
ToSend[++ToSendMax] = SEC_F;
// Convert from last byte pos to length
ToSendMax++;
}
static void CodeIso14443aAsTag(const uint8_t *cmd, uint16_t len)
{
uint8_t par[MAX_PARITY_SIZE];
GetParity(cmd, len, par);
CodeIso14443aAsTagPar(cmd, len, par);
}
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;
LastProxToAirDuration = 8 * ToSendMax - 4;
} else {
ToSend[++ToSendMax] = SEC_E;
LastProxToAirDuration = 8 * ToSendMax;
}
b >>= 1;
}
// Send stopbit
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, uint8_t *parity, int *len)
{
// 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.
UartInit(received, parity);
// clear RXRDY:
uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
for(;;) {
WDT_HIT();
if(BUTTON_PRESS()) return FALSE;
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
if(MillerDecoding(b, 0)) {
*len = Uart.len;
return TRUE;
}
}
}
}
static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded);
int EmSend4bitEx(uint8_t resp, bool correctionNeeded);
int EmSend4bit(uint8_t resp);
int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par);
int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded);
int EmSendCmd(uint8_t *resp, uint16_t respLen);
int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par);
bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity);
static uint8_t* free_buffer_pointer;
typedef struct {
uint8_t* response;
size_t response_n;
uint8_t* modulation;
size_t modulation_n;
uint32_t ProxToAirDuration;
} tag_response_info_t;
bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) {
// Example 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 and the time needed to transfer them
response_info->modulation_n = ToSendMax;
response_info->ProxToAirDuration = LastProxToAirDuration;
return true;
}
// "precompile" responses. There are 7 predefined responses with a total of 28 bytes data to transmit.
// Coded responses need one byte per bit to transfer (data, parity, start, stop, correction)
// 28 * 8 data bits, 28 * 1 parity bits, 7 start bits, 7 stop bits, 7 correction bits
// -> need 273 bytes buffer
// 44 * 8 data bits, 44 * 1 parity bits, 9 start bits, 9 stop bits, 9 correction bits --370
// 47 * 8 data bits, 47 * 1 parity bits, 10 start bits, 10 stop bits, 10 correction bits
#define ALLOCATED_TAG_MODULATION_BUFFER_SIZE 453
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 = ALLOCATED_TAG_MODULATION_BUFFER_SIZE;
// 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 flags, byte_t* data)
{
uint32_t counters[] = {0,0,0};
//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[] = {0,0,0,0,0,0,0,0,0,0};
uint8_t ar_nr_collected = 0;
uint8_t sak;
// PACK response to PWD AUTH for EV1/NTAG
uint8_t response8[4] = {0,0,0,0};
// The first response contains the ATQA (note: bytes are transmitted in reverse order).
uint8_t response1[2] = {0,0};
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] = 0x44;
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;
case 5: { // MIFARE TNP3XXX
// Says: I am a toy
response1[0] = 0x01;
response1[1] = 0x0f;
sak = 0x01;
} break;
case 6: { // MIFARE Mini
// Says: I am a Mifare Mini, 320b
response1[0] = 0x44;
response1[1] = 0x00;
sak = 0x09;
} break;
case 7: { // NTAG?
// Says: I am a NTAG,
response1[0] = 0x44;
response1[1] = 0x00;
sak = 0x00;
// PACK
response8[0] = 0x80;
response8[1] = 0x80;
ComputeCrc14443(CRC_14443_A, response8, 2, &response8[2], &response8[3]);
// uid not supplied then get from emulator memory
if (data[0]==0) {
uint16_t start = 4 * (0+12);
uint8_t emdata[8];
emlGetMemBt( emdata, start, sizeof(emdata));
memcpy(data, emdata, 3); //uid bytes 0-2
memcpy(data+3, emdata+4, 4); //uid bytes 3-7
flags |= FLAG_7B_UID_IN_DATA;
}
} 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] = {0x00};
// Check if the uid uses the (optional) part
uint8_t response2a[5] = {0x00};
if (flags & FLAG_7B_UID_IN_DATA) {
response2[0] = 0x88;
response2[1] = data[0];
response2[2] = data[1];
response2[3] = data[2];
response2a[0] = data[3];
response2a[1] = data[4];
response2a[2] = data[5];
response2a[3] = data[6]; //??
response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3];
// Configure the ATQA and SAK accordingly
response1[0] |= 0x40;
sak |= 0x04;
} else {
memcpy(response2, data, 4);
//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] = {0x00};
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] = {0x00};
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, 0x80, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS:
// Format byte = 0x58: FSCI=0x08 (FSC=256), TA(1) and TC(1) present,
// TA(1) = 0x80: different divisors not supported, DR = 1, DS = 1
// TB(1) = not present. Defaults: FWI = 4 (FWT = 256 * 16 * 2^4 * 1/fc = 4833us), SFGI = 0 (SFG = 256 * 16 * 2^0 * 1/fc = 302us)
// TC(1) = 0x02: CID supported, NAD not supported
ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]);
// Prepare GET_VERSION (different for UL EV-1 / NTAG)
//uint8_t response7_EV1[] = {0x00, 0x04, 0x03, 0x01, 0x01, 0x00, 0x0b, 0x03, 0xfd, 0xf7}; //EV1 48bytes VERSION.
//uint8_t response7_NTAG[] = {0x00, 0x04, 0x04, 0x02, 0x01, 0x00, 0x11, 0x03, 0x01, 0x9e}; //NTAG 215
// Prepare CHK_TEARING
//uint8_t response9[] = {0xBD,0x90,0x3f};
#define TAG_RESPONSE_COUNT 10
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
{ .response = response8, .response_n = sizeof(response8) } // EV1/NTAG PACK response
};
//{ .response = response7_NTAG, .response_n = sizeof(response7_NTAG)}, // EV1/NTAG GET_VERSION response
//{ .response = response9, .response_n = sizeof(response9) } // EV1/NTAG CHK_TEAR response
// Allocate 512 bytes for the dynamic modulation, created when the reader queries 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
};
// We need to listen to the high-frequency, peak-detected path.
iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
BigBuf_free_keep_EM();
// allocate buffers:
uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
free_buffer_pointer = BigBuf_malloc(ALLOCATED_TAG_MODULATION_BUFFER_SIZE);
// clear trace
clear_trace();
set_tracing(TRUE);
// 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]);
int len = 0;
// 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;
cmdsRecvd = 0;
tag_response_info_t* p_response;
LED_A_ON();
for(;;) {
WDT_HIT();
// Clean receive command buffer
if(!GetIso14443aCommandFromReader(receivedCmd, receivedCmdPar, &len)) {
DbpString("Button press");
break;
}
p_response = NULL;
// 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
uint8_t block = receivedCmd[1];
// if Ultralight or NTAG (4 byte blocks)
if ( tagType == 7 || tagType == 2 ) {
//first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
uint16_t start = 4 * (block+12);
uint8_t emdata[MAX_MIFARE_FRAME_SIZE];
emlGetMemBt( emdata, start, 16);
AppendCrc14443a(emdata, 16);
EmSendCmdEx(emdata, sizeof(emdata), false);
// We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
p_response = NULL;
} else { // all other tags (16 byte block tags)
EmSendCmdEx(data+(4*receivedCmd[1]),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] == 0x3A) { // Received a FAST READ (ranged read)
uint8_t emdata[MAX_FRAME_SIZE];
//first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
int start = (receivedCmd[1]+12) * 4;
int len = (receivedCmd[2] - receivedCmd[1] + 1) * 4;
emlGetMemBt( emdata, start, len);
AppendCrc14443a(emdata, len);
EmSendCmdEx(emdata, len+2, false);
p_response = NULL;
} else if(receivedCmd[0] == 0x3C && tagType == 7) { // Received a READ SIGNATURE --
// ECC data, taken from a NTAG215 amiibo token. might work. LEN: 32, + 2 crc
//first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
uint16_t start = 4 * 4;
uint8_t emdata[34];
emlGetMemBt( emdata, start, 32);
AppendCrc14443a(emdata, 32);
EmSendCmdEx(emdata, sizeof(emdata), false);
//uint8_t data[] = {0x56,0x06,0xa6,0x4f,0x43,0x32,0x53,0x6f,
// 0x43,0xda,0x45,0xd6,0x61,0x38,0xaa,0x1e,
// 0xcf,0xd3,0x61,0x36,0xca,0x5f,0xbb,0x05,
// 0xce,0x21,0x24,0x5b,0xa6,0x7a,0x79,0x07,
// 0x00,0x00};
//AppendCrc14443a(data, sizeof(data)-2);
//EmSendCmdEx(data,sizeof(data),false);
p_response = NULL;
} else if (receivedCmd[0] == 0x39 && tagType == 7) { // Received a READ COUNTER --
uint8_t index = receivedCmd[1];
uint8_t data[] = {0x00,0x00,0x00,0x14,0xa5};
if ( counters[index] > 0) {
num_to_bytes(counters[index], 3, data);
AppendCrc14443a(data, sizeof(data)-2);
}
EmSendCmdEx(data,sizeof(data),false);
p_response = NULL;
} else if (receivedCmd[0] == 0xA5 && tagType == 7) { // Received a INC COUNTER --
// number of counter
uint8_t counter = receivedCmd[1];
uint32_t val = bytes_to_num(receivedCmd+2,4);
counters[counter] = val;
// send ACK
uint8_t ack[] = {0x0a};
EmSendCmdEx(ack,sizeof(ack),false);
p_response = NULL;
} else if(receivedCmd[0] == 0x3E && tagType == 7) { // Received a CHECK_TEARING_EVENT --
//first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
uint8_t emdata[3];
uint8_t counter=0;
if (receivedCmd[1]<3) counter = receivedCmd[1];
emlGetMemBt( emdata, 10+counter, 1);
AppendCrc14443a(emdata, sizeof(emdata)-2);
EmSendCmdEx(emdata, sizeof(emdata), false);
p_response = NULL;
//p_response = &responses[9];
} else if(receivedCmd[0] == 0x50) { // Received a HALT
LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
p_response = NULL;
} else if(receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61) { // Received an authentication request
if ( tagType == 7 ) { // IF NTAG /EV1 0x60 == GET_VERSION, not a authentication request.
uint8_t emdata[10];
emlGetMemBt( emdata, 0, 8 );
AppendCrc14443a(emdata, sizeof(emdata)-2);
EmSendCmdEx(emdata, sizeof(emdata), false);
p_response = NULL;
//p_response = &responses[7];
} else {
p_response = &responses[5]; order = 7;
}
} else if(receivedCmd[0] == 0xE0) { // Received a RATS request
if (tagType == 1 || tagType == 2) { // RATS not supported
EmSend4bit(CARD_NACK_NA);
p_response = NULL;
} else {
p_response = &responses[6]; order = 70;
}
} else if (order == 7 && len == 8) { // Received {nr] and {ar} (part of authentication)
LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
uint32_t nonce = bytes_to_num(response5,4);
uint32_t nr = bytes_to_num(receivedCmd,4);
uint32_t ar = bytes_to_num(receivedCmd+4,4);
//Dbprintf("Auth attempt {nonce}{nr}{ar}: %08x %08x %08x", nonce, nr, ar);
if(flags & FLAG_NR_AR_ATTACK )
{
if(ar_nr_collected < 2){
// Avoid duplicates... probably not necessary, nr should vary.
//if(ar_nr_responses[3] != nr){
ar_nr_responses[ar_nr_collected*5] = 0;
ar_nr_responses[ar_nr_collected*5+1] = 0;
ar_nr_responses[ar_nr_collected*5+2] = nonce;
ar_nr_responses[ar_nr_collected*5+3] = nr;
ar_nr_responses[ar_nr_collected*5+4] = ar;
ar_nr_collected++;
//}
}
if(ar_nr_collected > 1 ) {
if (MF_DBGLEVEL >= 2) {
Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
Dbprintf("../tools/mfkey/mfkey32 %07x%08x %08x %08x %08x %08x %08x",
ar_nr_responses[0], // UID1
ar_nr_responses[1], // UID2
ar_nr_responses[2], // NT
ar_nr_responses[3], // AR1
ar_nr_responses[4], // NR1
ar_nr_responses[8], // AR2
ar_nr_responses[9] // NR2
);
Dbprintf("../tools/mfkey/mfkey32v2 %06x%08x %08x %08x %08x %08x %08x %08x",
ar_nr_responses[0], // UID1
ar_nr_responses[1], // UID2
ar_nr_responses[2], // NT1
ar_nr_responses[3], // AR1
ar_nr_responses[4], // NR1
ar_nr_responses[7], // NT2
ar_nr_responses[8], // AR2
ar_nr_responses[9] // NR2
);
}
uint8_t len = ar_nr_collected*5*4;
cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,len,0,&ar_nr_responses,len);
ar_nr_collected = 0;
memset(ar_nr_responses, 0x00, len);
}
}
} else if (receivedCmd[0] == 0x1a ) // ULC authentication
{
}
else if (receivedCmd[0] == 0x1b) // NTAG / EV-1 authentication
{
if ( tagType == 7 ) {
uint16_t start = 13; //first 4 blocks of emu are [getversion answer - check tearing - pack - 0x00]
uint8_t emdata[4];
emlGetMemBt( emdata, start, 2);
AppendCrc14443a(emdata, 2);
EmSendCmdEx(emdata, sizeof(emdata), false);
p_response = NULL;
//p_response = &responses[8]; // PACK response
uint32_t pwd = bytes_to_num(receivedCmd+1,4);
if ( MF_DBGLEVEL >= 3) Dbprintf("Auth attempt: %08x", pwd);
}
} else {
// Check for ISO 14443A-4 compliant commands, look at left nibble
switch (receivedCmd[0]) {
case 0x02:
case 0x03: { // IBlock (command no CID)
dynamic_response_info.response[0] = receivedCmd[0];
dynamic_response_info.response[1] = 0x90;
dynamic_response_info.response[2] = 0x00;
dynamic_response_info.response_n = 3;
} break;
case 0x0B:
case 0x0A: { // IBlock (command CID)
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: { // ping / pong
dynamic_response_info.response[0] = 0xAB;
dynamic_response_info.response[1] = 0x00;
dynamic_response_info.response_n = 2;
} break;
case 0xCA:
case 0xC2: { // Readers sends deselect command
dynamic_response_info.response[0] = 0xCA;
dynamic_response_info.response[1] = 0x00;
dynamic_response_info.response_n = 2;
} break;
default: {
// Never seen this command before
LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
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");
LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
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++; }
if(cmdsRecvd > 999) {
DbpString("1000 commands later...");
break;
}
cmdsRecvd++;
if (p_response != NULL) {
EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52);
// do the tracing for the previous reader request and this tag answer:
uint8_t par[MAX_PARITY_SIZE] = {0x00};
GetParity(p_response->response, p_response->response_n, par);
EmLogTrace(Uart.output,
Uart.len,
Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
Uart.parity,
p_response->response,
p_response->response_n,
LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
(LastTimeProxToAirStart + p_response->ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
par);
}
if (!tracing) {
Dbprintf("Trace Full. Simulation stopped.");
break;
}
}
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
set_tracing(FALSE);
BigBuf_free_keep_EM();
LED_A_OFF();
if (MF_DBGLEVEL >= 4){
Dbprintf("-[ Wake ups after halt [%d]", happened);
Dbprintf("-[ Messages after halt [%d]", happened2);
Dbprintf("-[ Num of received cmd [%d]", cmdsRecvd);
}
}
// 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 |= (1 << 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: transfer at next possible time, taking into account
// request guard time and frame delay time
// if == 0: transfer immediately and return time of transfer
// if != 0: delay transfer until time specified
//-------------------------------------------------------------------------------------
static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing)
{
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
uint32_t ThisTransferTime = 0;
if (timing) {
if(*timing == 0) { // Measure time
*timing = (GetCountSspClk() + 8) & 0xfffffff8;
} else {
PrepareDelayedTransfer(*timing & 0x00000007); // Delay transfer (fine tuning - up to 7 MF clock ticks)
}
if(MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
while(GetCountSspClk() < (*timing & 0xfffffff8)); // Delay transfer (multiple of 8 MF clock ticks)
LastTimeProxToAirStart = *timing;
} else {
ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8);
while(GetCountSspClk() < ThisTransferTime);
LastTimeProxToAirStart = ThisTransferTime;
}
// clear TXRDY
AT91C_BASE_SSC->SSC_THR = SEC_Y;
uint16_t c = 0;
for(;;) {
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
AT91C_BASE_SSC->SSC_THR = cmd[c];
++c;
if(c >= len)
break;
}
}
NextTransferTime = MAX(NextTransferTime, LastTimeProxToAirStart + REQUEST_GUARD_TIME);
}
//-----------------------------------------------------------------------------
// Prepare reader command (in bits, support short frames) to send to FPGA
//-----------------------------------------------------------------------------
void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8_t *parity)
{
int i, j;
int last = 0;
uint8_t b;
ToSendReset();
// Start of Communication (Seq. Z)
ToSend[++ToSendMax] = SEC_Z;
LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
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;
LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
last = 1;
} else {
if (last == 0) {
// Sequence Z
ToSend[++ToSendMax] = SEC_Z;
LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
} else {
// Sequence Y
ToSend[++ToSendMax] = SEC_Y;
last = 0;
}
}
b >>= 1;
}
// Only transmit parity bit if we transmitted a complete byte
if (j == 8 && parity != NULL) {
// Get the parity bit
if (parity[i>>3] & (0x80 >> (i&0x0007))) {
// Sequence X
ToSend[++ToSendMax] = SEC_X;
LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
last = 1;
} else {
if (last == 0) {
// Sequence Z
ToSend[++ToSendMax] = SEC_Z;
LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
} else {
// Sequence Y
ToSend[++ToSendMax] = SEC_Y;
last = 0;
}
}
}
}
// End of Communication: Logic 0 followed by Sequence Y
if (last == 0) {
// Sequence Z
ToSend[++ToSendMax] = SEC_Z;
LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
} else {
// Sequence Y
ToSend[++ToSendMax] = SEC_Y;
last = 0;
}
ToSend[++ToSendMax] = SEC_Y;
// Convert to length of command:
++ToSendMax;
}
//-----------------------------------------------------------------------------
// Prepare reader command to send to FPGA
//-----------------------------------------------------------------------------
void CodeIso14443aAsReaderPar(const uint8_t *cmd, uint16_t len, const uint8_t *parity)
{
//CodeIso14443aBitsAsReaderPar(cmd, len*8, parity);
CodeIso14443aBitsAsReaderPar(cmd, len<<3, parity);
}
//-----------------------------------------------------------------------------
// 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, uint16_t *len, uint8_t *parity)
{
*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(63) |
ADC_MODE_STARTUP_TIME(1) |
ADC_MODE_SAMPLE_HOLD_TIME(15);
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.
UartInit(received, parity);
// Clear RXRDY:
uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
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 ((MAX_ADC_HF_VOLTAGE * (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;
}
}
// receive and test the miller decoding
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
if(MillerDecoding(b, 0)) {
*len = Uart.len;
return 0;
}
}
}
}
static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded)
{
uint8_t b;
uint16_t i = 0;
uint32_t ThisTransferTime;
// Modulate Manchester
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
// include correction bit if necessary
if (Uart.parityBits & 0x01) {
correctionNeeded = TRUE;
}
if(correctionNeeded) {
// 1236, so correction bit needed
i = 0;
} else {
i = 1;
}
// clear receiving shift register and holding register
while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
b = AT91C_BASE_SSC->SSC_RHR; (void) b;
while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
b = AT91C_BASE_SSC->SSC_RHR; (void) b;
// wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line)
for (uint16_t j = 0; j < 5; j++) { // allow timeout - better late than never
while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
if (AT91C_BASE_SSC->SSC_RHR) break;
}
while ((ThisTransferTime = GetCountSspClk()) & 0x00000007);
// Clear TXRDY:
AT91C_BASE_SSC->SSC_THR = SEC_F;
// send cycle
for(; i < respLen; ) {
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
AT91C_BASE_SSC->SSC_THR = resp[i++];
FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
}
if(BUTTON_PRESS()) break;
}
// Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
uint8_t fpga_queued_bits = FpgaSendQueueDelay >> 3; // twich /8 ?? >>3,
for (i = 0; i <= fpga_queued_bits/8 + 1; ) {
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
AT91C_BASE_SSC->SSC_THR = SEC_F;
FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
i++;
}
}
LastTimeProxToAirStart = ThisTransferTime + (correctionNeeded?8:0);
return 0;
}
int EmSend4bitEx(uint8_t resp, bool correctionNeeded){
Code4bitAnswerAsTag(resp);
int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
// do the tracing for the previous reader request and this tag answer:
uint8_t par[1] = {0x00};
GetParity(&resp, 1, par);
EmLogTrace(Uart.output,
Uart.len,
Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
Uart.parity,
&resp,
1,
LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
(LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
par);
return res;
}
int EmSend4bit(uint8_t resp){
return EmSend4bitEx(resp, false);
}
int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par){
CodeIso14443aAsTagPar(resp, respLen, par);
int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
// do the tracing for the previous reader request and this tag answer:
EmLogTrace(Uart.output,
Uart.len,
Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
Uart.parity,
resp,
respLen,
LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
(LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
par);
return res;
}
int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded){
uint8_t par[MAX_PARITY_SIZE] = {0x00};
GetParity(resp, respLen, par);
return EmSendCmdExPar(resp, respLen, correctionNeeded, par);
}
int EmSendCmd(uint8_t *resp, uint16_t respLen){
uint8_t par[MAX_PARITY_SIZE] = {0x00};
GetParity(resp, respLen, par);
return EmSendCmdExPar(resp, respLen, false, par);
}
int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par){
return EmSendCmdExPar(resp, respLen, false, par);
}
bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity)
{
// we cannot exactly measure the end and start of a received command from reader. However we know that the delay from
// end of the received command to start of the tag's (simulated by us) answer is n*128+20 or n*128+84 resp.
// with n >= 9. The start of the tags answer can be measured and therefore the end of the received command be calculated:
uint16_t reader_modlen = reader_EndTime - reader_StartTime;
uint16_t approx_fdt = tag_StartTime - reader_EndTime;
uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20;
reader_EndTime = tag_StartTime - exact_fdt;
reader_StartTime = reader_EndTime - reader_modlen;
if (!LogTrace(reader_data, reader_len, reader_StartTime, reader_EndTime, reader_Parity, TRUE))
return FALSE;
else
return(!LogTrace(tag_data, tag_len, tag_StartTime, tag_EndTime, tag_Parity, FALSE));
}
//-----------------------------------------------------------------------------
// 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, uint8_t *receivedResponsePar, uint16_t offset)
{
uint32_t c = 0x00;
// 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
DemodInit(receivedResponse, receivedResponsePar);
// clear RXRDY:
uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
for(;;) {
WDT_HIT();
if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
if(ManchesterDecoding(b, offset, 0)) {
NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD);
return TRUE;
} else if (c++ > iso14a_timeout && Demod.state == DEMOD_UNSYNCD) {
return FALSE;
}
}
}
}
void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_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
//LogTrace(frame, nbytes(bits), LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_READER, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_READER, par, TRUE);
LogTrace(frame, nbytes(bits), (LastTimeProxToAirStart<<4) + DELAY_ARM2AIR_AS_READER, ((LastTimeProxToAirStart + LastProxToAirDuration)<<4) + DELAY_ARM2AIR_AS_READER, par, TRUE);
}
void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *timing)
{
//ReaderTransmitBitsPar(frame, len*8, par, timing);
ReaderTransmitBitsPar(frame, len<<3, par, timing);
}
void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing)
{
// Generate parity and redirect
uint8_t par[MAX_PARITY_SIZE] = {0x00};
//GetParity(frame, len/8, par);
GetParity(frame, len >> 3, par);
ReaderTransmitBitsPar(frame, len, par, timing);
}
void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *timing)
{
// Generate parity and redirect
uint8_t par[MAX_PARITY_SIZE] = {0x00};
GetParity(frame, len, par);
//ReaderTransmitBitsPar(frame, len*8, par, timing);
ReaderTransmitBitsPar(frame, len<<3, par, timing);
}
int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset, uint8_t *parity)
{
if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, offset))
return FALSE;
//LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
LogTrace(receivedAnswer, Demod.len, (Demod.startTime<<4) - DELAY_AIR2ARM_AS_READER, (Demod.endTime<<4) - DELAY_AIR2ARM_AS_READER, parity, FALSE);
return Demod.len;
}
int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity)
{
if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, 0))
return FALSE;
//LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
LogTrace(receivedAnswer, Demod.len, (Demod.startTime<<4) - DELAY_AIR2ARM_AS_READER, (Demod.endTime<<4) - DELAY_AIR2ARM_AS_READER, parity, FALSE);
return Demod.len;
}
// performs iso14443a anticollision (optional) and card select procedure
// fills the uid and cuid pointer unless NULL
// fills the card info record unless NULL
// if anticollision is false, then the UID must be provided in uid_ptr[]
// and num_cascades must be set (1: 4 Byte UID, 2: 7 Byte UID, 3: 10 Byte UID)
int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, uint32_t *cuid_ptr, bool anticollision, uint8_t num_cascades) {
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[MAX_FRAME_SIZE] = {0}; // theoretically. A usual RATS will be much smaller
uint8_t resp_par[MAX_PARITY_SIZE] = {0};
byte_t uid_resp[4] = {0};
size_t uid_resp_len = 0;
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, NULL, NULL);
// Receive the ATQA
if(!ReaderReceive(resp, resp_par)) return 0;
if(p_hi14a_card) {
memcpy(p_hi14a_card->atqa, resp, 2);
p_hi14a_card->uidlen = 0;
memset(p_hi14a_card->uid,0,10);
}
if (anticollision) {
// clear uid
if (uid_ptr)
memset(uid_ptr,0,10);
}
// check for proprietary anticollision:
if ((resp[0] & 0x1F) == 0) return 3;
// 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;
if (anticollision) {
// SELECT_ALL
ReaderTransmit(sel_all, sizeof(sel_all), NULL);
if (!ReaderReceive(resp, resp_par)) 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 / 8] |= 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, resp_par)) 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);
}
} else {
if (cascade_level < num_cascades - 1) {
uid_resp[0] = 0x88;
memcpy(uid_resp+1, uid_ptr+cascade_level*3, 3);
} else {
memcpy(uid_resp, uid_ptr+cascade_level*3, 4);
}
}
uid_resp_len = 4;
// 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 received during anticollision, or the provided 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, resp_par)) return 0;
sak = resp[0];
// Test if more parts of the uid are coming
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
uid_resp[0] = uid_resp[1];
uid_resp[1] = uid_resp[2];
uid_resp[2] = uid_resp[3];
uid_resp_len = 3;
}
if(uid_ptr && anticollision)
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;
}
// non iso14443a compliant tag
if( (sak & 0x20) == 0) return 2;
// Request for answer to select
AppendCrc14443a(rats, 2);
ReaderTransmit(rats, sizeof(rats), NULL);
if (!(len = ReaderReceive(resp, resp_par))) 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;
// set default timeout based on ATS
iso14a_set_ATS_timeout(resp);
return 1;
}
void iso14443a_setup(uint8_t fpga_minor_mode) {
FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
// Set up the synchronous serial port
FpgaSetupSsc();
// connect Demodulated Signal to ADC:
SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
// Signal field is on with the appropriate LED
if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD
|| fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN) {
LED_D_ON();
} else {
LED_D_OFF();
}
FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode);
// Start the timer
StartCountSspClk();
DemodReset();
UartReset();
NextTransferTime = 2*DELAY_ARM2AIR_AS_READER;
iso14a_set_timeout(10*106); // 10ms default
}
int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data) {
uint8_t parity[MAX_PARITY_SIZE] = {0x00};
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, parity);
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] & 0xffff;
size_t lenbits = c->arg[1] >> 16;
uint32_t timeout = c->arg[2];
uint32_t arg0 = 0;
byte_t buf[USB_CMD_DATA_SIZE] = {0x00};
uint8_t par[MAX_PARITY_SIZE] = {0x00};
if (param & ISO14A_CONNECT)
clear_trace();
set_tracing(TRUE);
if (param & ISO14A_REQUEST_TRIGGER)
iso14a_set_trigger(TRUE);
if (param & ISO14A_CONNECT) {
iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN);
if(!(param & ISO14A_NO_SELECT)) {
iso14a_card_select_t *card = (iso14a_card_select_t*)buf;
arg0 = iso14443a_select_card(NULL,card,NULL, true, 0);
cmd_send(CMD_ACK,arg0,card->uidlen,0,buf,sizeof(iso14a_card_select_t));
}
}
if (param & ISO14A_SET_TIMEOUT)
iso14a_set_timeout(timeout);
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) {
if(param & ISO14A_TOPAZMODE) {
AppendCrc14443b(cmd,len);
} else {
AppendCrc14443a(cmd,len);
}
len += 2;
if (lenbits) lenbits += 16;
}
if(lenbits>0) { // want to send a specific number of bits (e.g. short commands)
if(param & ISO14A_TOPAZMODE) {
int bits_to_send = lenbits;
uint16_t i = 0;
ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 7), NULL, NULL); // first byte is always short (7bits) and no parity
bits_to_send -= 7;
while (bits_to_send > 0) {
ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 8), NULL, NULL); // following bytes are 8 bit and no parity
bits_to_send -= 8;
}
} else {
GetParity(cmd, lenbits/8, par);
ReaderTransmitBitsPar(cmd, lenbits, par, NULL); // bytes are 8 bit with odd parity
}
} else { // want to send complete bytes only
if(param & ISO14A_TOPAZMODE) {
uint16_t i = 0;
ReaderTransmitBitsPar(&cmd[i++], 7, NULL, NULL); // first byte: 7 bits, no paritiy
while (i < len) {
ReaderTransmitBitsPar(&cmd[i++], 8, NULL, NULL); // following bytes: 8 bits, no paritiy
}
} else {
ReaderTransmit(cmd,len, NULL); // 8 bits, odd parity
}
}
arg0 = ReaderReceive(buf, par);
cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
}
if (param & ISO14A_REQUEST_TRIGGER)
iso14a_set_trigger(FALSE);
if (param & ISO14A_NO_DISCONNECT)
return;
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
set_tracing(FALSE);
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) {
if (nt1 == nt2) return 0;
uint32_t nttmp1 = nt1;
uint32_t nttmp2 = nt2;
for (uint16_t i = 1; i < 0xFFFF; i += 8) {
nttmp1 = prng_successor(nttmp1, 1); if (nttmp1 == nt2) return i;
nttmp2 = prng_successor(nttmp2, 1); if (nttmp2 == nt1) return -i;
nttmp1 = prng_successor(nttmp1, 2); if (nttmp1 == nt2) return i+1;
nttmp2 = prng_successor(nttmp2, 2); if (nttmp2 == nt1) return -i-1;
nttmp1 = prng_successor(nttmp1, 3); if (nttmp1 == nt2) return i+2;
nttmp2 = prng_successor(nttmp2, 3); if (nttmp2 == nt1) return -i-2;
nttmp1 = prng_successor(nttmp1, 4); if (nttmp1 == nt2) return i+3;
nttmp2 = prng_successor(nttmp2, 4); if (nttmp2 == nt1) return -i-3;
nttmp1 = prng_successor(nttmp1, 5); if (nttmp1 == nt2) return i+4;
nttmp2 = prng_successor(nttmp2, 5); if (nttmp2 == nt1) return -i-4;
nttmp1 = prng_successor(nttmp1, 6); if (nttmp1 == nt2) return i+5;
nttmp2 = prng_successor(nttmp2, 6); if (nttmp2 == nt1) return -i-5;
nttmp1 = prng_successor(nttmp1, 7); if (nttmp1 == nt2) return i+6;
nttmp2 = prng_successor(nttmp2, 7); if (nttmp2 == nt1) return -i-6;
nttmp1 = prng_successor(nttmp1, 8); if (nttmp1 == nt2) return i+7;
nttmp2 = prng_successor(nttmp2, 8); if (nttmp2 == nt1) return -i-7;
}
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, uint8_t block )
{
// Mifare AUTH
//uint8_t mf_auth[] = { 0x60,0x00,0xf5,0x7b };
//uint8_t mf_auth[] = { 0x60,0x05, 0x58, 0x2c };
uint8_t mf_auth[] = { 0x60,0x00, 0x00, 0x00 };
uint8_t mf_nr_ar[] = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
static uint8_t mf_nr_ar3 = 0;
mf_auth[1] = block;
AppendCrc14443a(mf_auth, 2);
uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE] = {0x00};
uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE] = {0x00};
byte_t nt_diff = 0;
uint8_t par[1] = {0}; // maximum 8 Bytes to be sent here, 1 byte parity is therefore enough
static byte_t par_low = 0;
uint8_t uid[10] = {0};
//uint32_t cuid = 0;
uint32_t nt = 0;
uint32_t previous_nt = 0;
static uint32_t nt_attacked = 0;
byte_t par_list[8] = {0x00};
byte_t ks_list[8] = {0x00};
static uint32_t sync_time = 0;
static int32_t sync_cycles = 0;
int catch_up_cycles = 0;
int last_catch_up = 0;
uint16_t elapsed_prng_sequences = 1;
uint16_t consecutive_resyncs = 0;
int isOK = 0;
#define PRNG_SEQUENCE_LENGTH (1 << 16);
#define MAX_UNEXPECTED_RANDOM 4 // maximum number of unexpected (i.e. real) random numbers when trying to sync. Then give up.
#define MAX_SYNC_TRIES 32
#define NUM_DEBUG_INFOS 8 // per strategy
#define MAX_STRATEGY 3
uint16_t unexpected_random = 0;
uint16_t sync_tries = 0;
uint16_t strategy = 0;
uint32_t halt_time = 0;
clear_trace();
set_tracing(TRUE);
LED_A_ON();
LED_B_OFF();
LED_C_OFF();
if (first_try)
iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
// free eventually allocated BigBuf memory. We want all for tracing.
BigBuf_free();
if (first_try) {
sync_time = GetCountSspClk() & 0xfffffff8;
sync_cycles = PRNG_SEQUENCE_LENGTH; //65536; //0x10000 // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
mf_nr_ar3 = 0;
nt_attacked = 0;
par[0] = 0;
} else {
// we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same)
mf_nr_ar3++;
mf_nr_ar[3] = mf_nr_ar3;
par[0] = par_low;
}
LED_C_ON();
for(uint16_t i = 0; TRUE; ++i) {
WDT_HIT();
// Test if the action was cancelled
if(BUTTON_PRESS()) {
isOK = -1;
break;
}
if (strategy == 2) {
// test with additional halt command
halt_time = 0;
int len = mifare_sendcmd_short(NULL, false, 0x50, 0x00, receivedAnswer, receivedAnswerPar, &halt_time);
if (len && MF_DBGLEVEL >= 3)
Dbprintf("Unexpected response of %d bytes to halt command.", len);
}
if (strategy == 3) {
// test with FPGA power off/on
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
SpinDelay(200);
iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
SpinDelay(100);
sync_time = GetCountSspClk() & 0xfffffff8;
WDT_HIT();
}
if (!iso14443a_select_card(uid, NULL, NULL, true, 0)) {
if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card\n");
continue;
}
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(GetCountSspClk() > sync_time) {
++elapsed_prng_sequences;
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, receivedAnswerPar))
continue;
// Transmit reader nonce with fake par
ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
previous_nt = nt;
nt = bytes_to_num(receivedAnswer, 4);
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
unexpected_random++;
if (unexpected_random > MAX_UNEXPECTED_RANDOM) {
isOK = -3; // Card has an unpredictable PRNG. Give up
break;
} else {
continue; // continue trying...
}
}
if (++sync_tries > MAX_SYNC_TRIES) {
if (strategy > MAX_STRATEGY || MF_DBGLEVEL < 3) {
isOK = -4; // Card's PRNG runs at an unexpected frequency or resets unexpectedly
break;
} else {
continue;
}
}
sync_cycles = (sync_cycles - nt_distance)/elapsed_prng_sequences;
if (sync_cycles <= 0)
sync_cycles += PRNG_SEQUENCE_LENGTH;
if (MF_DBGLEVEL >= 3)
Dbprintf("calibrating in cycle %d. nt_distance=%d, elapsed_prng_sequences=%d, new sync_cycles: %d\n", i, nt_distance, elapsed_prng_sequences, 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;
}
// average?
catch_up_cycles /= elapsed_prng_sequences;
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 += 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);
last_catch_up = 0;
catch_up_cycles = 0;
consecutive_resyncs = 0;
}
continue;
}
// Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
if (ReaderReceive(receivedAnswer, receivedAnswerPar)) {
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[0] & 0xE0; // there is no need to check all parities for other nt_diff. Parity Bits for mf_nr_ar[0..2] won't change
par_list[nt_diff] = SwapBits(par[0], 8);
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[0] = par_low;
} else {
if (nt_diff == 0 && first_try) {
par[0]++;
if (par[0] == 0x00) { // tried all 256 possible parities without success. Card doesn't send NACK.
isOK = -2;
break;
}
} else {
par[0] = ((par[0] & 0x1F) + 1) | par_low;
}
}
consecutive_resyncs = 0;
}
mf_nr_ar[3] &= 0x1F;
WDT_HIT();
// reset sync_time.
if ( isOK == 1) {
sync_time = 0;
sync_cycles = 0;
mf_nr_ar3 = 0;
nt_attacked = 0;
par[0] = 0;
}
byte_t buf[28] = {0x00};
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);
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
LEDsoff();
set_tracing(FALSE);
}
/**
*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;
uint16_t 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[MAX_MIFARE_FRAME_SIZE] = {0x00};
uint8_t receivedCmd_par[MAX_MIFARE_PARITY_SIZE] = {0x00};
uint8_t response[MAX_MIFARE_FRAME_SIZE] = {0x00};
uint8_t response_par[MAX_MIFARE_PARITY_SIZE] = {0x00};
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}; // Mifare Classic
//uint8_t rSAK[] = {0x09, 0x3f, 0xcc }; // Mifare Mini
uint8_t rSAK1[] = {0x04, 0xda, 0x17};
//uint8_t rAUTH_NT[] = {0x01, 0x01, 0x01, 0x01};
uint8_t rAUTH_NT[] = {0x55, 0x41, 0x49, 0x92};
uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
//Here, we collect UID1,UID2,NT,AR,NR,0,0,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[] = {0,0,0,0,0,0,0,0,0,0};
uint8_t ar_nr_collected = 0;
// 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);
}
}
// save uid.
ar_nr_responses[0*5] = bytes_to_num(rUIDBCC1+1, 3);
if ( _7BUID )
ar_nr_responses[0*5+1] = bytes_to_num(rUIDBCC2, 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;
rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
}
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]);
}
}
// We need to listen to the high-frequency, peak-detected path.
iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
// free eventually allocated BigBuf memory but keep Emulator Memory
BigBuf_free_keep_EM();
// clear trace
clear_trace();
set_tracing(TRUE);
bool finished = FALSE;
while (!BUTTON_PRESS() && !finished && !usb_poll_validate_length()) {
WDT_HIT();
// find reader field
if (cardSTATE == MFEMUL_NOFIELD) {
vHf = (MAX_ADC_HF_VOLTAGE * 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, receivedCmd_par);
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:{
LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
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)) {
EmSendCmd(_7BUID?rSAK1:rSAK, _7BUID?sizeof(rSAK1):sizeof(rSAK));
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;
}
case MFEMUL_AUTH1:{
if( len != 8) {
cardSTATE_TO_IDLE();
LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
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 && cardAUTHSC == 2){
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*5] = 0;
//ar_nr_responses[ar_nr_collected*5+1] = 0;
ar_nr_responses[ar_nr_collected*5+2] = nonce;
ar_nr_responses[ar_nr_collected*5+3] = nr;
ar_nr_responses[ar_nr_collected*5+4] = ar;
ar_nr_collected++;
}
// Interactive mode flag, means we need to send ACK
if(flags & FLAG_INTERACTIVE && ar_nr_collected == 2)
finished = true;
}
// --- 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 >= 4) Dbprintf("AUTH FAILED for sector %d with key %c. cardRr=%08x, succ=%08x",
// cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
// 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
// -- which is the correct response. /piwi
//cardSTATE_TO_IDLE();
//LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
//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 for sector %d with key %c. time=%d",
cardAUTHSC,
cardAUTHKEY == 0 ? 'A' : 'B',
GetTickCount() - authTimer
);
}
break;
}
case MFEMUL_SELECT2:{
if (!len) {
LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
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) {
LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
break;
}
cardSTATE = MFEMUL_WORK;
//goto lbWORK;
//intentional fall-through to the next case-stmt
}
case MFEMUL_WORK:{
if (len == 0) {
LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
break;
}
bool encrypted_data = (cardAUTHKEY != 0xFF) ;
// decrypt seqence
if(encrypted_data)
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 >= 4) 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 >= 4) 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) {
LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
break;
}
if(receivedCmd[0] == 0x30 // read block
|| receivedCmd[0] == 0xA0 // write block
|| receivedCmd[0] == 0xC0 // inc
|| receivedCmd[0] == 0xC1 // dec
|| receivedCmd[0] == 0xC2 // restore
|| receivedCmd[0] == 0xB0) { // transfer
if (receivedCmd[1] >= 16 * 4) {
EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
if (MF_DBGLEVEL >= 4) 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 >= 4) 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 >= 4) 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, response_par);
EmSendCmdPar(response, 18, response_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 >= 4) Dbprintf("RECV 0xA0 write block %d (%02x)",receivedCmd[1],receivedCmd[1]);
EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
cardSTATE = MFEMUL_WRITEBL2;
cardWRBL = receivedCmd[1];
break;
}
// increment, decrement, restore
if (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2) {
if (MF_DBGLEVEL >= 4) 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 >= 4) 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 >= 4) 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);
LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
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));
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;
} else {
cardSTATE_TO_IDLE();
LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
}
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;
}
LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
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;
}
LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
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;
}
LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
cardSTATE = MFEMUL_WORK;
break;
}
}
}
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
LEDsoff();
// Interactive mode flag, means we need to send ACK
if(flags & FLAG_INTERACTIVE) {
//May just aswell send the collected ar_nr in the response aswell
uint8_t len = ar_nr_collected*5*4;
cmd_send(CMD_ACK, CMD_SIMULATE_MIFARE_CARD, len, 0, &ar_nr_responses, len);
}
if(flags & FLAG_NR_AR_ATTACK && MF_DBGLEVEL >= 1 ) {
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 %06x%08x %08x %08x %08x %08x %08x",
ar_nr_responses[0], // UID1
ar_nr_responses[1], // UID2
ar_nr_responses[2], // NT
ar_nr_responses[3], // AR1
ar_nr_responses[4], // NR1
ar_nr_responses[8], // AR2
ar_nr_responses[9] // NR2
);
Dbprintf("../tools/mfkey/mfkey32v2 %06x%08x %08x %08x %08x %08x %08x %08x",
ar_nr_responses[0], // UID1
ar_nr_responses[1], // UID2
ar_nr_responses[2], // NT1
ar_nr_responses[3], // AR1
ar_nr_responses[4], // NR1
ar_nr_responses[7], // NT2
ar_nr_responses[8], // AR2
ar_nr_responses[9] // NR2
);
} else {
Dbprintf("Failed to obtain two AR/NR pairs!");
if(ar_nr_collected > 0 ) {
Dbprintf("Only got these: UID=%06x%08x, nonce=%08x, AR1=%08x, NR1=%08x",
ar_nr_responses[0], // UID1
ar_nr_responses[1], // UID2
ar_nr_responses[2], // NT
ar_nr_responses[3], // AR1
ar_nr_responses[4] // NR1
);
}
}
}
if (MF_DBGLEVEL >= 1) Dbprintf("Emulator stopped. Tracing: %d trace length: %d ", tracing, BigBuf_get_traceLen());
set_tracing(FALSE);
}
//-----------------------------------------------------------------------------
// 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
LEDsoff();
// init trace buffer
clear_trace();
set_tracing(TRUE);
// 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[MAX_MIFARE_FRAME_SIZE] = {0x00};
uint8_t receivedCmdPar[MAX_MIFARE_PARITY_SIZE] = {0x00};
// The response (tag -> reader) that we're receiving.
uint8_t receivedResponse[MAX_MIFARE_FRAME_SIZE] = {0x00};
uint8_t receivedResponsePar[MAX_MIFARE_PARITY_SIZE] = {0x00};
iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
// free eventually allocated BigBuf memory
BigBuf_free();
// allocate the DMA buffer, used to stream samples from the FPGA
uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
uint8_t *data = dmaBuf;
uint8_t previous_data = 0;
int maxDataLen = 0;
int dataLen = 0;
bool ReaderIsActive = FALSE;
bool TagIsActive = FALSE;
// Set up the demodulator for tag -> reader responses.
DemodInit(receivedResponse, receivedResponsePar);
// Set up the demodulator for the reader -> tag commands
UartInit(receivedCmd, receivedCmdPar);
// Setup for the DMA.
FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
LED_D_OFF();
// init sniffer
MfSniffInit();
// And now we loop, receiving samples.
for(uint32_t sniffCounter = 0; TRUE; ) {
if(BUTTON_PRESS()) {
DbpString("cancelled by button");
break;
}
LED_A_ON();
WDT_HIT();
if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time
// check if a transaction is completed (timeout after 2000ms).
// if yes, stop the DMA transfer and send what we have so far to the client
if (MfSniffSend(2000)) {
// Reset everything - we missed some sniffed data anyway while the DMA was stopped
sniffCounter = 0;
data = dmaBuf;
maxDataLen = 0;
ReaderIsActive = FALSE;
TagIsActive = FALSE;
FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
}
}
int register readBufDataP = data - dmaBuf; // number of bytes we have processed so far
int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred
if (readBufDataP <= dmaBufDataP) // we are processing the same block of data which is currently being transferred
dataLen = dmaBufDataP - readBufDataP; // number of bytes still to be processed
else
dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed
// test for length of buffer
if(dataLen > maxDataLen) { // we are more behind than ever...
maxDataLen = dataLen;
if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
break;
}
}
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 (sniffCounter & 0x01) {
// no need to try decoding tag data if the reader is sending
if(!TagIsActive) {
uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
if(MillerDecoding(readerdata, (sniffCounter-1)*4)) {
LED_C_INV();
if (MfSniffLogic(receivedCmd, Uart.len, Uart.parity, Uart.bitCount, TRUE)) break;
/* And ready to receive another command. */
UartInit(receivedCmd, receivedCmdPar);
/* And also reset the demod code */
DemodReset();
}
ReaderIsActive = (Uart.state != STATE_UNSYNCD);
}
// no need to try decoding tag data if the reader is sending
if(!ReaderIsActive) {
uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) {
LED_C_INV();
if (MfSniffLogic(receivedResponse, Demod.len, Demod.parity, Demod.bitCount, FALSE)) break;
// And ready to receive another response.
DemodReset();
// And reset the Miller decoder including its (now outdated) input buffer
UartInit(receivedCmd, receivedCmdPar);
}
TagIsActive = (Demod.state != DEMOD_UNSYNCD);
}
}
previous_data = *data;
sniffCounter++;
data++;
if(data == dmaBuf + DMA_BUFFER_SIZE)
data = dmaBuf;
} // main cycle
FpgaDisableSscDma();
MfSniffEnd();
LEDsoff();
Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len);
set_tracing(FALSE);
}
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