git.zerfleddert.de Git - proxmark3-svn/blob - armsrc/iso14443a.c

   1  //-----------------------------------------------------------------------------
   2 // Merlok - June 2011, 2012
   3 // Gerhard de Koning Gans - May 2008
   4 // Hagen Fritsch - June 2010
   5 //
   6 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
   7 // at your option, any later version. See the LICENSE.txt file for the text of
   8 // the license.
   9 //-----------------------------------------------------------------------------
  10 // Routines to support ISO 14443 type A.
  11 //-----------------------------------------------------------------------------
  12
  13 #include "proxmark3.h"
  14 #include "apps.h"
  15 #include "util.h"
  16 #include "string.h"
  17 #include "cmd.h"
  18 #include "iso14443crc.h"
  19 #include "iso14443a.h"
  20 #include "iso14443b.h"
  21 #include "crapto1.h"
  22 #include "mifareutil.h"
  23 #include "BigBuf.h"
  24 #include "parity.h"
  25
  26 static uint32_t iso14a_timeout;
  27 int rsamples = 0;
  28 uint8_t trigger = 0;
  29 // the block number for the ISO14443-4 PCB
  30 static uint8_t iso14_pcb_blocknum = 0;
  31
  32 //
  33 // ISO14443 timing:
  34 //
  35 // minimum time between the start bits of consecutive transfers from reader to tag: 7000 carrier (13.56Mhz) cycles
  36 #define REQUEST_GUARD_TIME (7000/16 + 1)
  37 // minimum time between last modulation of tag and next start bit from reader to tag: 1172 carrier cycles
  38 #define FRAME_DELAY_TIME_PICC_TO_PCD (1172/16 + 1)
  39 // bool LastCommandWasRequest = FALSE;
  40
  41 //
  42 // Total delays including SSC-Transfers between ARM and FPGA. These are in carrier clock cycles (1/13,56MHz)
  43 //
  44 // When the PM acts as reader and is receiving tag data, it takes
  45 // 3 ticks delay in the AD converter
  46 // 16 ticks until the modulation detector completes and sets curbit
  47 // 8 ticks until bit_to_arm is assigned from curbit
  48 // 8*16 ticks for the transfer from FPGA to ARM
  49 // 4*16 ticks until we measure the time
  50 // - 8*16 ticks because we measure the time of the previous transfer
  51 #define DELAY_AIR2ARM_AS_READER (3 + 16 + 8 + 8*16 + 4*16 - 8*16)
  52
  53 // When the PM acts as a reader and is sending, it takes
  54 // 4*16 ticks until we can write data to the sending hold register
  55 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
  56 // 8 ticks until the first transfer starts
  57 // 8 ticks later the FPGA samples the data
  58 // 1 tick to assign mod_sig_coil
  59 #define DELAY_ARM2AIR_AS_READER (4*16 + 8*16 + 8 + 8 + 1)
  60
  61 // When the PM acts as tag and is receiving it takes
  62 // 2 ticks delay in the RF part (for the first falling edge),
  63 // 3 ticks for the A/D conversion,
  64 // 8 ticks on average until the start of the SSC transfer,
  65 // 8 ticks until the SSC samples the first data
  66 // 7*16 ticks to complete the transfer from FPGA to ARM
  67 // 8 ticks until the next ssp_clk rising edge
  68 // 4*16 ticks until we measure the time
  69 // - 8*16 ticks because we measure the time of the previous transfer
  70 #define DELAY_AIR2ARM_AS_TAG (2 + 3 + 8 + 8 + 7*16 + 8 + 4*16 - 8*16)
  71
  72 // The FPGA will report its internal sending delay in
  73 uint16_t FpgaSendQueueDelay;
  74 // the 5 first bits are the number of bits buffered in mod_sig_buf
  75 // the last three bits are the remaining ticks/2 after the mod_sig_buf shift
  76 #define DELAY_FPGA_QUEUE (FpgaSendQueueDelay<<1)
  77
  78 // When the PM acts as tag and is sending, it takes
  79 // 4*16 ticks until we can write data to the sending hold register
  80 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
  81 // 8 ticks until the first transfer starts
  82 // 8 ticks later the FPGA samples the data
  83 // + a varying number of ticks in the FPGA Delay Queue (mod_sig_buf)
  84 // + 1 tick to assign mod_sig_coil
  85 #define DELAY_ARM2AIR_AS_TAG (4*16 + 8*16 + 8 + 8 + DELAY_FPGA_QUEUE + 1)
  86
  87 // When the PM acts as sniffer and is receiving tag data, it takes
  88 // 3 ticks A/D conversion
  89 // 14 ticks to complete the modulation detection
  90 // 8 ticks (on average) until the result is stored in to_arm
  91 // + the delays in transferring data - which is the same for
  92 // sniffing reader and tag data and therefore not relevant
  93 #define DELAY_TAG_AIR2ARM_AS_SNIFFER (3 + 14 + 8)
  94
  95 // When the PM acts as sniffer and is receiving reader data, it takes
  96 // 2 ticks delay in analogue RF receiver (for the falling edge of the
  97 // start bit, which marks the start of the communication)
  98 // 3 ticks A/D conversion
  99 // 8 ticks on average until the data is stored in to_arm.
 100 // + the delays in transferring data - which is the same for
 101 // sniffing reader and tag data and therefore not relevant
 102 #define DELAY_READER_AIR2ARM_AS_SNIFFER (2 + 3 + 8)
 103
 104 //variables used for timing purposes:
 105 //these are in ssp_clk cycles:
 106 static uint32_t NextTransferTime;
 107 static uint32_t LastTimeProxToAirStart;
 108 static uint32_t LastProxToAirDuration;
 109
 110 // CARD TO READER - manchester
 111 // Sequence D: 11110000 modulation with subcarrier during first half
 112 // Sequence E: 00001111 modulation with subcarrier during second half
 113 // Sequence F: 00000000 no modulation with subcarrier
 114 // READER TO CARD - miller
 115 // Sequence X: 00001100 drop after half a period
 116 // Sequence Y: 00000000 no drop
 117 // Sequence Z: 11000000 drop at start
 118 #define SEC_D 0xf0
 119 #define SEC_E 0x0f
 120 #define SEC_F 0x00
 121 #define SEC_X 0x0c
 122 #define SEC_Y 0x00
 123 #define SEC_Z 0xc0
 124
 125 void iso14a_set_trigger(bool enable) {
 126         trigger = enable;
 127 }
 128
 129 void iso14a_set_timeout(uint32_t timeout) {
 130         iso14a_timeout = timeout;
 131         if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443A Timeout set to %ld (%dms)", iso14a_timeout, iso14a_timeout / 106);
 132 }
 133
 134 void iso14a_set_ATS_timeout(uint8_t *ats) {
 135
 136         uint8_t tb1;
 137         uint8_t fwi;
 138         uint32_t fwt;
 139
 140         if (ats[0] > 1) {                                                       // there is a format byte T0
 141                 if ((ats[1] & 0x20) == 0x20) {                  // there is an interface byte TB(1)
 142
 143                         if ((ats[1] & 0x10) == 0x10)            // there is an interface byte TA(1) preceding TB(1)
 144                                 tb1 = ats[3];
 145                         else
 146                                 tb1 = ats[2];
 147
 148                         fwi = (tb1 & 0xf0) >> 4;                        // frame waiting indicator (FWI)
 149                         //fwt = 256 * 16 * (1 << fwi);          // frame waiting time (FWT) in 1/fc
 150                         fwt = 4096 * (1 << fwi);
 151
 152                         //iso14a_set_timeout(fwt/(8*16));
 153                         iso14a_set_timeout(fwt/128);
 154                 }
 155         }
 156 }
 157
 158 //-----------------------------------------------------------------------------
 159 // Generate the parity value for a byte sequence
 160 //
 161 //-----------------------------------------------------------------------------
 162 void GetParity(const uint8_t *pbtCmd, uint16_t iLen, uint8_t *par)
 163 {
 164         uint16_t paritybit_cnt = 0;
 165         uint16_t paritybyte_cnt = 0;
 166         uint8_t parityBits = 0;
 167
 168         for (uint16_t i = 0; i < iLen; i++) {
 169                 // Generate the parity bits
 170                 parityBits |= ((oddparity8(pbtCmd[i])) << (7-paritybit_cnt));
 171                 if (paritybit_cnt == 7) {
 172                         par[paritybyte_cnt] = parityBits;       // save 8 Bits parity
 173                         parityBits = 0;                                         // and advance to next Parity Byte
 174                         paritybyte_cnt++;
 175                         paritybit_cnt = 0;
 176                 } else {
 177                         paritybit_cnt++;
 178                 }
 179         }
 180
 181         // save remaining parity bits
 182         par[paritybyte_cnt] = parityBits;
 183
 184 }
 185
 186 void AppendCrc14443a(uint8_t* data, int len)
 187 {
 188         ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1);
 189 }
 190
 191 //=============================================================================
 192 // ISO 14443 Type A - Miller decoder
 193 //=============================================================================
 194 // Basics:
 195 // This decoder is used when the PM3 acts as a tag.
 196 // The reader will generate "pauses" by temporarily switching of the field.
 197 // At the PM3 antenna we will therefore measure a modulated antenna voltage.
 198 // The FPGA does a comparison with a threshold and would deliver e.g.:
 199 // ........  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  .......
 200 // The Miller decoder needs to identify the following sequences:
 201 // 2 (or 3) ticks pause followed by 6 (or 5) ticks unmodulated:         pause at beginning - Sequence Z ("start of communication" or a "0")
 202 // 8 ticks without a modulation:                                                                        no pause - Sequence Y (a "0" or "end of communication" or "no information")
 203 // 4 ticks unmodulated followed by 2 (or 3) ticks pause:                        pause in second half - Sequence X (a "1")
 204 // Note 1: the bitstream may start at any time. We therefore need to sync.
 205 // Note 2: the interpretation of Sequence Y and Z depends on the preceding sequence.
 206 //-----------------------------------------------------------------------------
 207 static tUart Uart;
 208
 209 // Lookup-Table to decide if 4 raw bits are a modulation.
 210 // We accept the following:
 211 // 0001  -   a 3 tick wide pause
 212 // 0011  -   a 2 tick wide pause, or a three tick wide pause shifted left
 213 // 0111  -   a 2 tick wide pause shifted left
 214 // 1001  -   a 2 tick wide pause shifted right
 215 const bool Mod_Miller_LUT[] = {
 216         FALSE,  TRUE, FALSE, TRUE,  FALSE, FALSE, FALSE, TRUE,
 217         FALSE,  TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE
 218 };
 219 #define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x000000F0) >> 4])
 220 #define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x0000000F)])
 221
 222 void UartReset()
 223 {
 224         Uart.state = STATE_UNSYNCD;
 225         Uart.bitCount = 0;
 226         Uart.len = 0;                                           // number of decoded data bytes
 227         Uart.parityLen = 0;                                     // number of decoded parity bytes
 228         Uart.shiftReg = 0;                                      // shiftreg to hold decoded data bits
 229         Uart.parityBits = 0;                            // holds 8 parity bits
 230         Uart.startTime = 0;
 231         Uart.endTime = 0;
 232
 233         Uart.byteCntMax = 0;
 234         Uart.posCnt = 0;
 235         Uart.syncBit = 9999;
 236 }
 237
 238 void UartInit(uint8_t *data, uint8_t *parity)
 239 {
 240         Uart.output = data;
 241         Uart.parity = parity;
 242         Uart.fourBits = 0x00000000;                     // clear the buffer for 4 Bits
 243         UartReset();
 244 }
 245
 246 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
 247 static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
 248 {
 249
 250         Uart.fourBits = (Uart.fourBits << 8) | bit;
 251
 252         if (Uart.state == STATE_UNSYNCD) {                                                                                      // not yet synced
 253
 254                 Uart.syncBit = 9999;                                                                                                    // not set
 255
 256                 // 00x11111 2|3 ticks pause followed by 6|5 ticks unmodulated           Sequence Z (a "0" or "start of communication")
 257                 // 11111111 8 ticks unmodulation                                                                        Sequence Y (a "0" or "end of communication" or "no information")
 258                 // 111100x1 4 ticks unmodulated followed by 2|3 ticks pause                     Sequence X (a "1")
 259
 260                 // The start bit is one ore more Sequence Y followed by a Sequence Z (... 11111111 00x11111). We need to distinguish from
 261                 // Sequence X followed by Sequence Y followed by Sequence Z     (111100x1 11111111 00x11111)
 262                 // we therefore look for a ...xx1111 11111111 00x11111xxxxxx... pattern
 263                 // (12 '1's followed by 2 '0's, eventually followed by another '0', followed by 5 '1's)
 264                 //
 265 #define ISO14443A_STARTBIT_MASK         0x07FFEF80              // mask is    00001111 11111111 1110 1111 10000000
 266 #define ISO14443A_STARTBIT_PATTERN      0x07FF8F80              // pattern is 00001111 11111111 1000 1111 10000000
 267
 268                 if              ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 0)) == ISO14443A_STARTBIT_PATTERN >> 0) Uart.syncBit = 7;
 269                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 1)) == ISO14443A_STARTBIT_PATTERN >> 1) Uart.syncBit = 6;
 270                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 2)) == ISO14443A_STARTBIT_PATTERN >> 2) Uart.syncBit = 5;
 271                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 3)) == ISO14443A_STARTBIT_PATTERN >> 3) Uart.syncBit = 4;
 272                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 4)) == ISO14443A_STARTBIT_PATTERN >> 4) Uart.syncBit = 3;
 273                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 5)) == ISO14443A_STARTBIT_PATTERN >> 5) Uart.syncBit = 2;
 274                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 6)) == ISO14443A_STARTBIT_PATTERN >> 6) Uart.syncBit = 1;
 275                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 7)) == ISO14443A_STARTBIT_PATTERN >> 7) Uart.syncBit = 0;
 276
 277                 if (Uart.syncBit != 9999) {                                                                                             // found a sync bit
 278                                 Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
 279                                 Uart.startTime -= Uart.syncBit;
 280                                 Uart.endTime = Uart.startTime;
 281                                 Uart.state = STATE_START_OF_COMMUNICATION;
 282                         }
 283
 284         } else {
 285
 286                 if (IsMillerModulationNibble1(Uart.fourBits >> Uart.syncBit)) {
 287                         if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) {         // Modulation in both halves - error
 288                                 UartReset();
 289                         } else {                                                                                                                        // Modulation in first half = Sequence Z = logic "0"
 290                                 if (Uart.state == STATE_MILLER_X) {                                                             // error - must not follow after X
 291                                         UartReset();
 292                                 } else {
 293                                         Uart.bitCount++;
 294                                         Uart.shiftReg = (Uart.shiftReg >> 1);                                           // add a 0 to the shiftreg
 295                                         Uart.state = STATE_MILLER_Z;
 296                                         Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 6;
 297                                         if(Uart.bitCount >= 9) {                                                                        // if we decoded a full byte (including parity)
 298                                                 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
 299                                                 Uart.parityBits <<= 1;                                                                  // make room for the parity bit
 300                                                 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01);               // store parity bit
 301                                                 Uart.bitCount = 0;
 302                                                 Uart.shiftReg = 0;
 303                                                 if((Uart.len&0x0007) == 0) {                                                    // every 8 data bytes
 304                                                         Uart.parity[Uart.parityLen++] = Uart.parityBits;        // store 8 parity bits
 305                                                         Uart.parityBits = 0;
 306                                                 }
 307                                         }
 308                                 }
 309                         }
 310                 } else {
 311                         if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) {         // Modulation second half = Sequence X = logic "1"
 312                                 Uart.bitCount++;
 313                                 Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100;                                   // add a 1 to the shiftreg
 314                                 Uart.state = STATE_MILLER_X;
 315                                 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 2;
 316                                 if(Uart.bitCount >= 9) {                                                                                // if we decoded a full byte (including parity)
 317                                         Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
 318                                         Uart.parityBits <<= 1;                                                                          // make room for the new parity bit
 319                                         Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01);                       // store parity bit
 320                                         Uart.bitCount = 0;
 321                                         Uart.shiftReg = 0;
 322                                         if ((Uart.len&0x0007) == 0) {                                                           // every 8 data bytes
 323                                                 Uart.parity[Uart.parityLen++] = Uart.parityBits;                // store 8 parity bits
 324                                                 Uart.parityBits = 0;
 325                                         }
 326                                 }
 327                         } else {                                                                                                                        // no modulation in both halves - Sequence Y
 328                                 if (Uart.state == STATE_MILLER_Z || Uart.state == STATE_MILLER_Y) {     // Y after logic "0" - End of Communication
 329                                         Uart.state = STATE_UNSYNCD;
 330                                         Uart.bitCount--;                                                                                        // last "0" was part of EOC sequence
 331                                         Uart.shiftReg <<= 1;                                                                            // drop it
 332                                         if(Uart.bitCount > 0) {                                                                         // if we decoded some bits
 333                                                 Uart.shiftReg >>= (9 - Uart.bitCount);                                  // right align them
 334                                                 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);               // add last byte to the output
 335                                                 Uart.parityBits <<= 1;                                                                  // add a (void) parity bit
 336                                                 Uart.parityBits <<= (8 - (Uart.len&0x0007));                    // left align parity bits
 337                                                 Uart.parity[Uart.parityLen++] = Uart.parityBits;                // and store it
 338                                                 return TRUE;
 339                                         } else if (Uart.len & 0x0007) {                                                         // there are some parity bits to store
 340                                                 Uart.parityBits <<= (8 - (Uart.len&0x0007));                    // left align remaining parity bits
 341                                                 Uart.parity[Uart.parityLen++] = Uart.parityBits;                // and store them
 342                                         }
 343                                         if (Uart.len) {
 344                                                 return TRUE;                                                                                    // we are finished with decoding the raw data sequence
 345                                         } else {
 346                                                 UartReset();                                                                                    // Nothing received - start over
 347                                         }
 348                                 }
 349                                 if (Uart.state == STATE_START_OF_COMMUNICATION) {                               // error - must not follow directly after SOC
 350                                         UartReset();
 351                                 } else {                                                                                                                // a logic "0"
 352                                         Uart.bitCount++;
 353                                         Uart.shiftReg = (Uart.shiftReg >> 1);                                           // add a 0 to the shiftreg
 354                                         Uart.state = STATE_MILLER_Y;
 355                                         if(Uart.bitCount >= 9) {                                                                        // if we decoded a full byte (including parity)
 356                                                 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
 357                                                 Uart.parityBits <<= 1;                                                                  // make room for the parity bit
 358                                                 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01);               // store parity bit
 359                                                 Uart.bitCount = 0;
 360                                                 Uart.shiftReg = 0;
 361                                                 if ((Uart.len&0x0007) == 0) {                                                   // every 8 data bytes
 362                                                         Uart.parity[Uart.parityLen++] = Uart.parityBits;        // store 8 parity bits
 363                                                         Uart.parityBits = 0;
 364                                                 }
 365                                         }
 366                                 }
 367                         }
 368                 }
 369
 370         }
 371
 372     return FALSE;       // not finished yet, need more data
 373 }
 374
 375
 376
 377 //=============================================================================
 378 // ISO 14443 Type A - Manchester decoder
 379 //=============================================================================
 380 // Basics:
 381 // This decoder is used when the PM3 acts as a reader.
 382 // The tag will modulate the reader field by asserting different loads to it. As a consequence, the voltage
 383 // at the reader antenna will be modulated as well. The FPGA detects the modulation for us and would deliver e.g. the following:
 384 // ........ 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 .......
 385 // The Manchester decoder needs to identify the following sequences:
 386 // 4 ticks modulated followed by 4 ticks unmodulated:   Sequence D = 1 (also used as "start of communication")
 387 // 4 ticks unmodulated followed by 4 ticks modulated:   Sequence E = 0
 388 // 8 ticks unmodulated:                                                                 Sequence F = end of communication
 389 // 8 ticks modulated:                                                                   A collision. Save the collision position and treat as Sequence D
 390 // Note 1: the bitstream may start at any time. We therefore need to sync.
 391 // Note 2: parameter offset is used to determine the position of the parity bits (required for the anticollision command only)
 392 static tDemod Demod;
 393
 394 // Lookup-Table to decide if 4 raw bits are a modulation.
 395 // We accept three or four "1" in any position
 396 const bool Mod_Manchester_LUT[] = {
 397         FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE,
 398         FALSE, FALSE, FALSE, TRUE,  FALSE, TRUE,  TRUE,  TRUE
 399 };
 400
 401 #define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4])
 402 #define IsManchesterModulationNibble2(b) (Mod_Manchester_LUT[(b & 0x000F)])
 403
 404
 405 void DemodReset()
 406 {
 407         Demod.state = DEMOD_UNSYNCD;
 408         Demod.len = 0;                                          // number of decoded data bytes
 409         Demod.parityLen = 0;
 410         Demod.shiftReg = 0;                                     // shiftreg to hold decoded data bits
 411         Demod.parityBits = 0;                           //
 412         Demod.collisionPos = 0;                         // Position of collision bit
 413         Demod.twoBits = 0xffff;                         // buffer for 2 Bits
 414         Demod.highCnt = 0;
 415         Demod.startTime = 0;
 416         Demod.endTime = 0;
 417
 418         //
 419         Demod.bitCount = 0;
 420         Demod.syncBit = 0xFFFF;
 421         Demod.samples = 0;
 422 }
 423
 424 void DemodInit(uint8_t *data, uint8_t *parity)
 425 {
 426         Demod.output = data;
 427         Demod.parity = parity;
 428         DemodReset();
 429 }
 430
 431 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
 432 static RAMFUNC int ManchesterDecoding(uint8_t bit, uint16_t offset, uint32_t non_real_time)
 433 {
 434
 435         Demod.twoBits = (Demod.twoBits << 8) | bit;
 436
 437         if (Demod.state == DEMOD_UNSYNCD) {
 438
 439                 if (Demod.highCnt < 2) {                                                                                        // wait for a stable unmodulated signal
 440                         if (Demod.twoBits == 0x0000) {
 441                                 Demod.highCnt++;
 442                         } else {
 443                                 Demod.highCnt = 0;
 444                         }
 445                 } else {
 446                         Demod.syncBit = 0xFFFF;                 // not set
 447                         if              ((Demod.twoBits & 0x7700) == 0x7000) Demod.syncBit = 7;
 448                         else if ((Demod.twoBits & 0x3B80) == 0x3800) Demod.syncBit = 6;
 449                         else if ((Demod.twoBits & 0x1DC0) == 0x1C00) Demod.syncBit = 5;
 450                         else if ((Demod.twoBits & 0x0EE0) == 0x0E00) Demod.syncBit = 4;
 451                         else if ((Demod.twoBits & 0x0770) == 0x0700) Demod.syncBit = 3;
 452                         else if ((Demod.twoBits & 0x03B8) == 0x0380) Demod.syncBit = 2;
 453                         else if ((Demod.twoBits & 0x01DC) == 0x01C0) Demod.syncBit = 1;
 454                         else if ((Demod.twoBits & 0x00EE) == 0x00E0) Demod.syncBit = 0;
 455                         if (Demod.syncBit != 0xFFFF) {
 456                                 Demod.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
 457                                 Demod.startTime -= Demod.syncBit;
 458                                 Demod.bitCount = offset;                        // number of decoded data bits
 459                                 Demod.state = DEMOD_MANCHESTER_DATA;
 460                         }
 461                 }
 462
 463         } else {
 464
 465                 if (IsManchesterModulationNibble1(Demod.twoBits >> Demod.syncBit)) {            // modulation in first half
 466                         if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) {    // ... and in second half = collision
 467                                 if (!Demod.collisionPos) {
 468                                         Demod.collisionPos = (Demod.len << 3) + Demod.bitCount;
 469                                 }
 470                         }                                                                                                                       // modulation in first half only - Sequence D = 1
 471                         Demod.bitCount++;
 472                         Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100;                         // in both cases, add a 1 to the shiftreg
 473                         if(Demod.bitCount == 9) {                                                                       // if we decoded a full byte (including parity)
 474                                 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
 475                                 Demod.parityBits <<= 1;                                                                 // make room for the parity bit
 476                                 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01);     // store parity bit
 477                                 Demod.bitCount = 0;
 478                                 Demod.shiftReg = 0;
 479                                 if((Demod.len&0x0007) == 0) {                                                   // every 8 data bytes
 480                                         Demod.parity[Demod.parityLen++] = Demod.parityBits;     // store 8 parity bits
 481                                         Demod.parityBits = 0;
 482                                 }
 483                         }
 484                         Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1) - 4;
 485                 } else {                                                                                                                // no modulation in first half
 486                         if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) {    // and modulation in second half = Sequence E = 0
 487                                 Demod.bitCount++;
 488                                 Demod.shiftReg = (Demod.shiftReg >> 1);                                 // add a 0 to the shiftreg
 489                                 if(Demod.bitCount >= 9) {                                                               // if we decoded a full byte (including parity)
 490                                         Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
 491                                         Demod.parityBits <<= 1;                                                         // make room for the new parity bit
 492                                         Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
 493                                         Demod.bitCount = 0;
 494                                         Demod.shiftReg = 0;
 495                                         if ((Demod.len&0x0007) == 0) {                                          // every 8 data bytes
 496                                                 Demod.parity[Demod.parityLen++] = Demod.parityBits;     // store 8 parity bits1
 497                                                 Demod.parityBits = 0;
 498                                         }
 499                                 }
 500                                 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1);
 501                         } else {                                                                                                        // no modulation in both halves - End of communication
 502                                 if(Demod.bitCount > 0) {                                                                // there are some remaining data bits
 503                                         Demod.shiftReg >>= (9 - Demod.bitCount);                        // right align the decoded bits
 504                                         Demod.output[Demod.len++] = Demod.shiftReg & 0xff;      // and add them to the output
 505                                         Demod.parityBits <<= 1;                                                         // add a (void) parity bit
 506                                         Demod.parityBits <<= (8 - (Demod.len&0x0007));          // left align remaining parity bits
 507                                         Demod.parity[Demod.parityLen++] = Demod.parityBits;     // and store them
 508                                         return TRUE;
 509                                 } else if (Demod.len & 0x0007) {                                                // there are some parity bits to store
 510                                         Demod.parityBits <<= (8 - (Demod.len&0x0007));          // left align remaining parity bits
 511                                         Demod.parity[Demod.parityLen++] = Demod.parityBits;     // and store them
 512                                 }
 513                                 if (Demod.len) {
 514                                         return TRUE;                                                                            // we are finished with decoding the raw data sequence
 515                                 } else {                                                                                                // nothing received. Start over
 516                                         DemodReset();
 517                                 }
 518                         }
 519                 }
 520         }
 521     return FALSE;       // not finished yet, need more data
 522 }
 523
 524 //=============================================================================
 525 // Finally, a `sniffer' for ISO 14443 Type A
 526 // Both sides of communication!
 527 //=============================================================================
 528
 529 //-----------------------------------------------------------------------------
 530 // Record the sequence of commands sent by the reader to the tag, with
 531 // triggering so that we start recording at the point that the tag is moved
 532 // near the reader.
 533 //-----------------------------------------------------------------------------
 534 void RAMFUNC SniffIso14443a(uint8_t param) {
 535         // param:
 536         // bit 0 - trigger from first card answer
 537         // bit 1 - trigger from first reader 7-bit request
 538         LEDsoff();
 539
 540         iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
 541
 542         // Allocate memory from BigBuf for some buffers
 543         // free all previous allocations first
 544         BigBuf_free(); BigBuf_Clear_ext(false);
 545
 546         // init trace buffer
 547         clear_trace();
 548         set_tracing(TRUE);
 549
 550         // The command (reader -> tag) that we're receiving.
 551         uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
 552         uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
 553
 554         // The response (tag -> reader) that we're receiving.
 555         uint8_t *receivedResponse = BigBuf_malloc(MAX_FRAME_SIZE);
 556         uint8_t *receivedResponsePar = BigBuf_malloc(MAX_PARITY_SIZE);
 557
 558         // The DMA buffer, used to stream samples from the FPGA
 559         uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
 560
 561         uint8_t *data = dmaBuf;
 562         uint8_t previous_data = 0;
 563         int maxDataLen = 0;
 564         int dataLen = 0;
 565         bool TagIsActive = FALSE;
 566         bool ReaderIsActive = FALSE;
 567
 568         // Set up the demodulator for tag -> reader responses.
 569         DemodInit(receivedResponse, receivedResponsePar);
 570
 571         // Set up the demodulator for the reader -> tag commands
 572         UartInit(receivedCmd, receivedCmdPar);
 573
 574         // Setup and start DMA.
 575         FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
 576
 577         // We won't start recording the frames that we acquire until we trigger;
 578         // a good trigger condition to get started is probably when we see a
 579         // response from the tag.
 580         // triggered == FALSE -- to wait first for card
 581         bool triggered = !(param & 0x03);
 582
 583         // And now we loop, receiving samples.
 584         for(uint32_t rsamples = 0; TRUE; ) {
 585
 586                 if(BUTTON_PRESS()) {
 587                         DbpString("cancelled by button");
 588                         break;
 589                 }
 590
 591                 LED_A_ON();
 592                 WDT_HIT();
 593
 594                 int register readBufDataP = data - dmaBuf;
 595                 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR;
 596                 if (readBufDataP <= dmaBufDataP){
 597                         dataLen = dmaBufDataP - readBufDataP;
 598                 } else {
 599                         dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP;
 600                 }
 601                 // test for length of buffer
 602                 if(dataLen > maxDataLen) {
 603                         maxDataLen = dataLen;
 604                         if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
 605                                 Dbprintf("blew circular buffer! dataLen=%d", dataLen);
 606                                 break;
 607                         }
 608                 }
 609                 if(dataLen < 1) continue;
 610
 611                 // primary buffer was stopped( <-- we lost data!
 612                 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
 613                         AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
 614                         AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
 615                         Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
 616                 }
 617                 // secondary buffer sets as primary, secondary buffer was stopped
 618                 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
 619                         AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
 620                         AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
 621                 }
 622
 623                 LED_A_OFF();
 624
 625                 if (rsamples & 0x01) {                          // Need two samples to feed Miller and Manchester-Decoder
 626
 627                         if(!TagIsActive) {              // no need to try decoding reader data if the tag is sending
 628                                 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
 629                                 if (MillerDecoding(readerdata, (rsamples-1)*4)) {
 630                                         LED_C_ON();
 631
 632                                         // check - if there is a short 7bit request from reader
 633                                         if ((!triggered) && (param & 0x02) && (Uart.len == 1) && (Uart.bitCount == 7)) triggered = TRUE;
 634
 635                                         if(triggered) {
 636                                                 if (!LogTrace(receivedCmd,
 637                                                                                 Uart.len,
 638                                                                                 Uart.startTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
 639                                                                                 Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
 640                                                                                 Uart.parity,
 641                                                                                 TRUE)) break;
 642                                         }
 643                                         /* And ready to receive another command. */
 644                                         UartReset();
 645                                         /* And also reset the demod code, which might have been */
 646                                         /* false-triggered by the commands from the reader. */
 647                                         DemodReset();
 648                                         LED_B_OFF();
 649                                 }
 650                                 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
 651                         }
 652
 653                         if(!ReaderIsActive) {           // no need to try decoding tag data if the reader is sending - and we cannot afford the time
 654                                 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
 655                                 if(ManchesterDecoding(tagdata, 0, (rsamples-1)*4)) {
 656                                         LED_B_ON();
 657
 658                                         if (!LogTrace(receivedResponse,
 659                                                                         Demod.len,
 660                                                                         Demod.startTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
 661                                                                         Demod.endTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
 662                                                                         Demod.parity,
 663                                                                         FALSE)) break;
 664
 665                                         if ((!triggered) && (param & 0x01)) triggered = TRUE;
 666
 667                                         // And ready to receive another response.
 668                                         DemodReset();
 669                                         // And reset the Miller decoder including itS (now outdated) input buffer
 670                                         UartInit(receivedCmd, receivedCmdPar);
 671
 672                                         LED_C_OFF();
 673                                 }
 674                                 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
 675                         }
 676                 }
 677
 678                 previous_data = *data;
 679                 rsamples++;
 680                 data++;
 681                 if(data == dmaBuf + DMA_BUFFER_SIZE) {
 682                         data = dmaBuf;
 683                 }
 684         } // main cycle
 685
 686         FpgaDisableSscDma();
 687         LEDsoff();
 688
 689         Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len);
 690         Dbprintf("traceLen=%d, Uart.output[0]=%08x", BigBuf_get_traceLen(), (uint32_t)Uart.output[0]);
 691
 692         set_tracing(FALSE);
 693 }
 694
 695 //-----------------------------------------------------------------------------
 696 // Prepare tag messages
 697 //-----------------------------------------------------------------------------
 698 static void CodeIso14443aAsTagPar(const uint8_t *cmd, uint16_t len, uint8_t *parity)
 699 {
 700         ToSendReset();
 701
 702         // Correction bit, might be removed when not needed
 703         ToSendStuffBit(0);
 704         ToSendStuffBit(0);
 705         ToSendStuffBit(0);
 706         ToSendStuffBit(0);
 707         ToSendStuffBit(1);  // 1
 708         ToSendStuffBit(0);
 709         ToSendStuffBit(0);
 710         ToSendStuffBit(0);
 711
 712         // Send startbit
 713         ToSend[++ToSendMax] = SEC_D;
 714         LastProxToAirDuration = 8 * ToSendMax - 4;
 715
 716         for(uint16_t i = 0; i < len; i++) {
 717                 uint8_t b = cmd[i];
 718
 719                 // Data bits
 720                 for(uint16_t j = 0; j < 8; j++) {
 721                         if(b & 1) {
 722                                 ToSend[++ToSendMax] = SEC_D;
 723                         } else {
 724                                 ToSend[++ToSendMax] = SEC_E;
 725                         }
 726                         b >>= 1;
 727                 }
 728
 729                 // Get the parity bit
 730                 if (parity[i>>3] & (0x80>>(i&0x0007))) {
 731                         ToSend[++ToSendMax] = SEC_D;
 732                         LastProxToAirDuration = 8 * ToSendMax - 4;
 733                 } else {
 734                         ToSend[++ToSendMax] = SEC_E;
 735                         LastProxToAirDuration = 8 * ToSendMax;
 736                 }
 737         }
 738
 739         // Send stopbit
 740         ToSend[++ToSendMax] = SEC_F;
 741
 742         // Convert from last byte pos to length
 743         ++ToSendMax;
 744 }
 745
 746 static void CodeIso14443aAsTag(const uint8_t *cmd, uint16_t len)
 747 {
 748         uint8_t par[MAX_PARITY_SIZE] = {0};
 749         GetParity(cmd, len, par);
 750         CodeIso14443aAsTagPar(cmd, len, par);
 751 }
 752
 753
 754 static void Code4bitAnswerAsTag(uint8_t cmd)
 755 {
 756         int i;
 757
 758         ToSendReset();
 759
 760         // Correction bit, might be removed when not needed
 761         ToSendStuffBit(0);
 762         ToSendStuffBit(0);
 763         ToSendStuffBit(0);
 764         ToSendStuffBit(0);
 765         ToSendStuffBit(1);  // 1
 766         ToSendStuffBit(0);
 767         ToSendStuffBit(0);
 768         ToSendStuffBit(0);
 769
 770         // Send startbit
 771         ToSend[++ToSendMax] = SEC_D;
 772
 773         uint8_t b = cmd;
 774         for(i = 0; i < 4; i++) {
 775                 if(b & 1) {
 776                         ToSend[++ToSendMax] = SEC_D;
 777                         LastProxToAirDuration = 8 * ToSendMax - 4;
 778                 } else {
 779                         ToSend[++ToSendMax] = SEC_E;
 780                         LastProxToAirDuration = 8 * ToSendMax;
 781                 }
 782                 b >>= 1;
 783         }
 784
 785         // Send stopbit
 786         ToSend[++ToSendMax] = SEC_F;
 787
 788         // Convert from last byte pos to length
 789         ToSendMax++;
 790 }
 791
 792 //-----------------------------------------------------------------------------
 793 // Wait for commands from reader
 794 // Stop when button is pressed
 795 // Or return TRUE when command is captured
 796 //-----------------------------------------------------------------------------
 797 static int GetIso14443aCommandFromReader(uint8_t *received, uint8_t *parity, int *len)
 798 {
 799     // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
 800     // only, since we are receiving, not transmitting).
 801     // Signal field is off with the appropriate LED
 802     LED_D_OFF();
 803     FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
 804
 805     // Now run a `software UART' on the stream of incoming samples.
 806         UartInit(received, parity);
 807
 808         // clear RXRDY:
 809     uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
 810
 811     for(;;) {
 812         WDT_HIT();
 813
 814         if(BUTTON_PRESS()) return FALSE;
 815
 816         if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
 817             b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
 818                         if(MillerDecoding(b, 0)) {
 819                                 *len = Uart.len;
 820                                 return TRUE;
 821                         }
 822                 }
 823     }
 824 }
 825
 826 static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded);
 827 int EmSend4bitEx(uint8_t resp, bool correctionNeeded);
 828 int EmSend4bit(uint8_t resp);
 829 int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par);
 830 int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded);
 831 int EmSendCmd(uint8_t *resp, uint16_t respLen);
 832 int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par);
 833 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
 834                                  uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity);
 835
 836 static uint8_t* free_buffer_pointer;
 837
 838 typedef struct {
 839   uint8_t* response;
 840   size_t   response_n;
 841   uint8_t* modulation;
 842   size_t   modulation_n;
 843   uint32_t ProxToAirDuration;
 844 } tag_response_info_t;
 845
 846 bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) {
 847         // Example response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes
 848         // This will need the following byte array for a modulation sequence
 849         //    144        data bits (18 * 8)
 850         //     18        parity bits
 851         //      2        Start and stop
 852         //      1        Correction bit (Answer in 1172 or 1236 periods, see FPGA)
 853         //      1        just for the case
 854         // ----------- +
 855         //    166 bytes, since every bit that needs to be send costs us a byte
 856         //
 857
 858
 859   // Prepare the tag modulation bits from the message
 860   CodeIso14443aAsTag(response_info->response,response_info->response_n);
 861
 862   // Make sure we do not exceed the free buffer space
 863   if (ToSendMax > max_buffer_size) {
 864     Dbprintf("Out of memory, when modulating bits for tag answer:");
 865     Dbhexdump(response_info->response_n,response_info->response,false);
 866     return false;
 867   }
 868
 869   // Copy the byte array, used for this modulation to the buffer position
 870   memcpy(response_info->modulation,ToSend,ToSendMax);
 871
 872   // Store the number of bytes that were used for encoding/modulation and the time needed to transfer them
 873   response_info->modulation_n = ToSendMax;
 874   response_info->ProxToAirDuration = LastProxToAirDuration;
 875
 876   return true;
 877 }
 878
 879
 880 // "precompile" responses. There are 7 predefined responses with a total of 28 bytes data to transmit.
 881 // Coded responses need one byte per bit to transfer (data, parity, start, stop, correction)
 882 // 28 * 8 data bits, 28 * 1 parity bits, 7 start bits, 7 stop bits, 7 correction bits
 883 // -> need 273 bytes buffer
 884 // 44 * 8 data bits, 44 * 1 parity bits, 9 start bits, 9 stop bits, 9 correction bits --370
 885 // 47 * 8 data bits, 47 * 1 parity bits, 10 start bits, 10 stop bits, 10 correction bits
 886 #define ALLOCATED_TAG_MODULATION_BUFFER_SIZE 453
 887
 888 bool prepare_allocated_tag_modulation(tag_response_info_t* response_info) {
 889   // Retrieve and store the current buffer index
 890   response_info->modulation = free_buffer_pointer;
 891
 892   // Determine the maximum size we can use from our buffer
 893   size_t max_buffer_size = ALLOCATED_TAG_MODULATION_BUFFER_SIZE;
 894
 895   // Forward the prepare tag modulation function to the inner function
 896   if (prepare_tag_modulation(response_info, max_buffer_size)) {
 897     // Update the free buffer offset
 898     free_buffer_pointer += ToSendMax;
 899     return true;
 900   } else {
 901     return false;
 902   }
 903 }
 904
 905 //-----------------------------------------------------------------------------
 906 // Main loop of simulated tag: receive commands from reader, decide what
 907 // response to send, and send it.
 908 //-----------------------------------------------------------------------------
 909 void SimulateIso14443aTag(int tagType, int flags, byte_t* data)
 910 {
 911         uint32_t counters[] = {0,0,0};
 912         //Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2
 913         // This can be used in a reader-only attack.
 914         // (it can also be retrieved via 'hf 14a list', but hey...
 915         uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0,0,0};
 916         uint8_t ar_nr_collected = 0;
 917
 918         uint8_t sak;
 919
 920         // PACK response to PWD AUTH for EV1/NTAG
 921         uint8_t response8[4] =  {0,0,0,0};
 922
 923         // The first response contains the ATQA (note: bytes are transmitted in reverse order).
 924         uint8_t response1[2] =  {0,0};
 925
 926         switch (tagType) {
 927                 case 1: { // MIFARE Classic
 928                         // Says: I am Mifare 1k - original line
 929                         response1[0] = 0x04;
 930                         response1[1] = 0x00;
 931                         sak = 0x08;
 932                 } break;
 933                 case 2: { // MIFARE Ultralight
 934                         // Says: I am a stupid memory tag, no crypto
 935                         response1[0] = 0x44;
 936                         response1[1] = 0x00;
 937                         sak = 0x00;
 938                 } break;
 939                 case 3: { // MIFARE DESFire
 940                         // Says: I am a DESFire tag, ph33r me
 941                         response1[0] = 0x04;
 942                         response1[1] = 0x03;
 943                         sak = 0x20;
 944                 } break;
 945                 case 4: { // ISO/IEC 14443-4
 946                         // Says: I am a javacard (JCOP)
 947                         response1[0] = 0x04;
 948                         response1[1] = 0x00;
 949                         sak = 0x28;
 950                 } break;
 951                 case 5: { // MIFARE TNP3XXX
 952                         // Says: I am a toy
 953                         response1[0] = 0x01;
 954                         response1[1] = 0x0f;
 955                         sak = 0x01;
 956                 } break;
 957                 case 6: { // MIFARE Mini
 958                         // Says: I am a Mifare Mini, 320b
 959                         response1[0] = 0x44;
 960                         response1[1] = 0x00;
 961                         sak = 0x09;
 962                 } break;
 963                 case 7: { // NTAG?
 964                         // Says: I am a NTAG,
 965                         response1[0] = 0x44;
 966                         response1[1] = 0x00;
 967                         sak = 0x00;
 968                         // PACK
 969                         response8[0] = 0x80;
 970                         response8[1] = 0x80;
 971                         ComputeCrc14443(CRC_14443_A, response8, 2, &response8[2], &response8[3]);
 972                         // uid not supplied then get from emulator memory
 973                         if (data[0]==0) {
 974                                 uint16_t start = 4 * (0+12);
 975                                 uint8_t emdata[8];
 976                                 emlGetMemBt( emdata, start, sizeof(emdata));
 977                                 memcpy(data, emdata, 3); //uid bytes 0-2
 978                                 memcpy(data+3, emdata+4, 4); //uid bytes 3-7
 979                                 flags |= FLAG_7B_UID_IN_DATA;
 980                         }
 981                 } break;
 982                 default: {
 983                         Dbprintf("Error: unkown tagtype (%d)",tagType);
 984                         return;
 985                 } break;
 986         }
 987
 988         // The second response contains the (mandatory) first 24 bits of the UID
 989         uint8_t response2[5] = {0x00};
 990
 991         // Check if the uid uses the (optional) part
 992         uint8_t response2a[5] = {0x00};
 993
 994         if (flags & FLAG_7B_UID_IN_DATA) {
 995                 response2[0] = 0x88;
 996                 response2[1] = data[0];
 997                 response2[2] = data[1];
 998                 response2[3] = data[2];
 999
1000                 response2a[0] = data[3];
1001                 response2a[1] = data[4];
1002                 response2a[2] = data[5];
1003                 response2a[3] = data[6]; //??
1004                 response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3];
1005
1006                 // Configure the ATQA and SAK accordingly
1007                 response1[0] |= 0x40;
1008                 sak |= 0x04;
1009         } else {
1010                 memcpy(response2, data, 4);
1011                 //num_to_bytes(uid_1st,4,response2);
1012                 // Configure the ATQA and SAK accordingly
1013                 response1[0] &= 0xBF;
1014                 sak &= 0xFB;
1015         }
1016
1017         // Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID.
1018         response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3];
1019
1020         // Prepare the mandatory SAK (for 4 and 7 byte UID)
1021         uint8_t response3[3]  = {0x00};
1022         response3[0] = sak;
1023         ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
1024
1025         // Prepare the optional second SAK (for 7 byte UID), drop the cascade bit
1026         uint8_t response3a[3]  = {0x00};
1027         response3a[0] = sak & 0xFB;
1028         ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
1029
1030         uint8_t response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce
1031         uint8_t response6[] = { 0x04, 0x58, 0x80, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS:
1032         // Format byte = 0x58: FSCI=0x08 (FSC=256), TA(1) and TC(1) present,
1033         // TA(1) = 0x80: different divisors not supported, DR = 1, DS = 1
1034         // 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)
1035         // TC(1) = 0x02: CID supported, NAD not supported
1036         ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]);
1037
1038         // Prepare GET_VERSION (different for UL EV-1 / NTAG)
1039         //uint8_t response7_EV1[] = {0x00, 0x04, 0x03, 0x01, 0x01, 0x00, 0x0b, 0x03, 0xfd, 0xf7};  //EV1 48bytes VERSION.
1040         //uint8_t response7_NTAG[] = {0x00, 0x04, 0x04, 0x02, 0x01, 0x00, 0x11, 0x03, 0x01, 0x9e}; //NTAG 215
1041
1042         // Prepare CHK_TEARING
1043         //uint8_t response9[] =  {0xBD,0x90,0x3f};
1044
1045         #define TAG_RESPONSE_COUNT 10
1046         tag_response_info_t responses[TAG_RESPONSE_COUNT] = {
1047                 { .response = response1,  .response_n = sizeof(response1)  },  // Answer to request - respond with card type
1048                 { .response = response2,  .response_n = sizeof(response2)  },  // Anticollision cascade1 - respond with uid
1049                 { .response = response2a, .response_n = sizeof(response2a) },  // Anticollision cascade2 - respond with 2nd half of uid if asked
1050                 { .response = response3,  .response_n = sizeof(response3)  },  // Acknowledge select - cascade 1
1051                 { .response = response3a, .response_n = sizeof(response3a) },  // Acknowledge select - cascade 2
1052                 { .response = response5,  .response_n = sizeof(response5)  },  // Authentication answer (random nonce)
1053                 { .response = response6,  .response_n = sizeof(response6)  },  // dummy ATS (pseudo-ATR), answer to RATS
1054
1055                 { .response = response8,   .response_n = sizeof(response8) }  // EV1/NTAG PACK response
1056         };
1057                 //{ .response = response7_NTAG, .response_n = sizeof(response7_NTAG)}, // EV1/NTAG GET_VERSION response
1058                 //{ .response = response9,      .response_n = sizeof(response9)     }  // EV1/NTAG CHK_TEAR response
1059
1060
1061         // Allocate 512 bytes for the dynamic modulation, created when the reader queries for it
1062         // Such a response is less time critical, so we can prepare them on the fly
1063         #define DYNAMIC_RESPONSE_BUFFER_SIZE 64
1064         #define DYNAMIC_MODULATION_BUFFER_SIZE 512
1065         uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
1066         uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
1067         tag_response_info_t dynamic_response_info = {
1068                 .response = dynamic_response_buffer,
1069                 .response_n = 0,
1070                 .modulation = dynamic_modulation_buffer,
1071                 .modulation_n = 0
1072         };
1073
1074         // We need to listen to the high-frequency, peak-detected path.
1075         iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1076
1077         BigBuf_free_keep_EM();
1078
1079         // allocate buffers:
1080         uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
1081         uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
1082         free_buffer_pointer = BigBuf_malloc(ALLOCATED_TAG_MODULATION_BUFFER_SIZE);
1083
1084         // clear trace
1085         clear_trace();
1086         set_tracing(TRUE);
1087
1088         // Prepare the responses of the anticollision phase
1089         // there will be not enough time to do this at the moment the reader sends it REQA
1090         for (size_t i=0; i<TAG_RESPONSE_COUNT; i++)
1091                 prepare_allocated_tag_modulation(&responses[i]);
1092
1093         int len = 0;
1094
1095         // To control where we are in the protocol
1096         int order = 0;
1097         int lastorder;
1098
1099         // Just to allow some checks
1100         int happened = 0;
1101         int happened2 = 0;
1102         int cmdsRecvd = 0;
1103
1104         cmdsRecvd = 0;
1105         tag_response_info_t* p_response;
1106
1107         LED_A_ON();
1108         for(;;) {
1109
1110                 WDT_HIT();
1111
1112                 // Clean receive command buffer
1113                 if(!GetIso14443aCommandFromReader(receivedCmd, receivedCmdPar, &len)) {
1114                         DbpString("Button press");
1115                         break;
1116                 }
1117
1118                 p_response = NULL;
1119
1120                 // Okay, look at the command now.
1121                 lastorder = order;
1122                 if(receivedCmd[0] == 0x26) { // Received a REQUEST
1123                         p_response = &responses[0]; order = 1;
1124                 } else if(receivedCmd[0] == 0x52) { // Received a WAKEUP
1125                         p_response = &responses[0]; order = 6;
1126                 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) {   // Received request for UID (cascade 1)
1127                         p_response = &responses[1]; order = 2;
1128                 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x95) {   // Received request for UID (cascade 2)
1129                         p_response = &responses[2]; order = 20;
1130                 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x93) {   // Received a SELECT (cascade 1)
1131                         p_response = &responses[3]; order = 3;
1132                 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x95) {   // Received a SELECT (cascade 2)
1133                         p_response = &responses[4]; order = 30;
1134                 } else if(receivedCmd[0] == 0x30) {     // Received a (plain) READ
1135                         uint8_t block = receivedCmd[1];
1136                         // if Ultralight or NTAG (4 byte blocks)
1137                         if ( tagType == 7 || tagType == 2 ) {
1138                                 //first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1139                                 uint16_t start = 4 * (block+12);
1140                                         uint8_t emdata[MAX_MIFARE_FRAME_SIZE];
1141                                         emlGetMemBt( emdata, start, 16);
1142                                         AppendCrc14443a(emdata, 16);
1143                                         EmSendCmdEx(emdata, sizeof(emdata), false);
1144                                 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1145                                 p_response = NULL;
1146                         } else { // all other tags (16 byte block tags)
1147                                 EmSendCmdEx(data+(4*receivedCmd[1]),16,false);
1148                                 // Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
1149                                 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1150                                 p_response = NULL;
1151                         }
1152                 } else if(receivedCmd[0] == 0x3A) {     // Received a FAST READ (ranged read)
1153
1154                                 uint8_t emdata[MAX_FRAME_SIZE];
1155                                 //first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1156                                 int start =  (receivedCmd[1]+12) * 4;
1157                                 int len   = (receivedCmd[2] - receivedCmd[1] + 1) * 4;
1158                                 emlGetMemBt( emdata, start, len);
1159                                 AppendCrc14443a(emdata, len);
1160                                 EmSendCmdEx(emdata, len+2, false);
1161                                 p_response = NULL;
1162
1163                 } else if(receivedCmd[0] == 0x3C && tagType == 7) {     // Received a READ SIGNATURE --
1164                                 //first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1165                                 uint16_t start = 4 * 4;
1166                                 uint8_t emdata[34];
1167                                 emlGetMemBt( emdata, start, 32);
1168                                 AppendCrc14443a(emdata, 32);
1169                                 EmSendCmdEx(emdata, sizeof(emdata), false);
1170                                 p_response = NULL;
1171                 } else if (receivedCmd[0] == 0x39 && tagType == 7) {    // Received a READ COUNTER --
1172                         uint8_t index = receivedCmd[1];
1173                         uint8_t data[] =  {0x00,0x00,0x00,0x14,0xa5};
1174                         if ( counters[index] > 0) {
1175                                 num_to_bytes(counters[index], 3, data);
1176                                 AppendCrc14443a(data, sizeof(data)-2);
1177                         }
1178                         EmSendCmdEx(data,sizeof(data),false);
1179                         p_response = NULL;
1180                 } else if (receivedCmd[0] == 0xA5 && tagType == 7) {    // Received a INC COUNTER --
1181                         // number of counter
1182                         uint8_t counter = receivedCmd[1];
1183                         uint32_t val = bytes_to_num(receivedCmd+2,4);
1184                         counters[counter] = val;
1185
1186                         // send ACK
1187                         uint8_t ack[] = {0x0a};
1188                         EmSendCmdEx(ack,sizeof(ack),false);
1189                         p_response = NULL;
1190
1191                 } else if(receivedCmd[0] == 0x3E && tagType == 7) {     // Received a CHECK_TEARING_EVENT --
1192                         //first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1193                         uint8_t emdata[3];
1194                         uint8_t counter=0;
1195                         if (receivedCmd[1]<3) counter = receivedCmd[1];
1196                         emlGetMemBt( emdata, 10+counter, 1);
1197                         AppendCrc14443a(emdata, sizeof(emdata)-2);
1198                         EmSendCmdEx(emdata, sizeof(emdata), false);
1199                         p_response = NULL;
1200                 } else if(receivedCmd[0] == 0x50) {     // Received a HALT
1201                         LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1202                         p_response = NULL;
1203                 } else if(receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61) {   // Received an authentication request
1204
1205                         if ( tagType == 7 ) {   // IF NTAG /EV1  0x60 == GET_VERSION, not a authentication request.
1206                                 uint8_t emdata[10];
1207                                 emlGetMemBt( emdata, 0, 8 );
1208                                 AppendCrc14443a(emdata, sizeof(emdata)-2);
1209                                 EmSendCmdEx(emdata, sizeof(emdata), false);
1210                                 p_response = NULL;
1211                         } else {
1212                                 p_response = &responses[5]; order = 7;
1213                         }
1214                 } else if(receivedCmd[0] == 0xE0) {     // Received a RATS request
1215                         if (tagType == 1 || tagType == 2) {     // RATS not supported
1216                                 EmSend4bit(CARD_NACK_NA);
1217                                 p_response = NULL;
1218                         } else {
1219                                 p_response = &responses[6]; order = 70;
1220                         }
1221                 } else if (order == 7 && len == 8) { // Received {nr] and {ar} (part of authentication)
1222                         LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1223                         uint32_t nonce = bytes_to_num(response5,4);
1224                         uint32_t nr = bytes_to_num(receivedCmd,4);
1225                         uint32_t ar = bytes_to_num(receivedCmd+4,4);
1226                         //Dbprintf("Auth attempt {nonce}{nr}{ar}: %08x %08x %08x", nonce, nr, ar);
1227
1228                         if(flags & FLAG_NR_AR_ATTACK )
1229                         {
1230                                 if(ar_nr_collected < 2){
1231                                         // Avoid duplicates... probably not necessary, nr should vary.
1232                                         //if(ar_nr_responses[3] != nr){
1233                                                 ar_nr_responses[ar_nr_collected*5]   = 0;
1234                                                 ar_nr_responses[ar_nr_collected*5+1] = 0;
1235                                                 ar_nr_responses[ar_nr_collected*5+2] = nonce;
1236                                                 ar_nr_responses[ar_nr_collected*5+3] = nr;
1237                                                 ar_nr_responses[ar_nr_collected*5+4] = ar;
1238                                                 ar_nr_collected++;
1239                                         //}
1240                                 }
1241
1242                                 if(ar_nr_collected > 1 ) {
1243
1244                                         if (MF_DBGLEVEL >= 2) {
1245                                                         Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
1246                                                         Dbprintf("../tools/mfkey/mfkey32 %07x%08x %08x %08x %08x %08x %08x",
1247                                                                 ar_nr_responses[0], // UID1
1248                                                                 ar_nr_responses[1], // UID2
1249                                                                 ar_nr_responses[2], // NT
1250                                                                 ar_nr_responses[3], // AR1
1251                                                                 ar_nr_responses[4], // NR1
1252                                                                 ar_nr_responses[8], // AR2
1253                                                                 ar_nr_responses[9]  // NR2
1254                                                         );
1255                                                         Dbprintf("../tools/mfkey/mfkey32v2 %06x%08x %08x %08x %08x %08x %08x %08x",
1256                                                                 ar_nr_responses[0], // UID1
1257                                                                 ar_nr_responses[1], // UID2
1258                                                                 ar_nr_responses[2], // NT1
1259                                                                 ar_nr_responses[3], // AR1
1260                                                                 ar_nr_responses[4], // NR1
1261                                                                 ar_nr_responses[7], // NT2
1262                                                                 ar_nr_responses[8], // AR2
1263                                                                 ar_nr_responses[9]  // NR2
1264                                                                 );
1265                                         }
1266                                         uint8_t len = ar_nr_collected*5*4;
1267                                         cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,len,0,&ar_nr_responses,len);
1268                                         ar_nr_collected = 0;
1269                                         memset(ar_nr_responses, 0x00, len);
1270                                 }
1271                         }
1272                 } else if (receivedCmd[0] == 0x1a ) // ULC authentication
1273                 {
1274
1275                 }
1276                 else if (receivedCmd[0] == 0x1b) // NTAG / EV-1 authentication
1277                 {
1278                         if ( tagType == 7 ) {
1279                                 uint16_t start = 13; //first 4 blocks of emu are [getversion answer - check tearing - pack - 0x00]
1280                                 uint8_t emdata[4];
1281                                 emlGetMemBt( emdata, start, 2);
1282                                 AppendCrc14443a(emdata, 2);
1283                                 EmSendCmdEx(emdata, sizeof(emdata), false);
1284                                 p_response = NULL;
1285                                 uint32_t pwd = bytes_to_num(receivedCmd+1,4);
1286
1287                                 if ( MF_DBGLEVEL >= 3)  Dbprintf("Auth attempt: %08x", pwd);
1288                         }
1289                 } else {
1290                         // Check for ISO 14443A-4 compliant commands, look at left nibble
1291                         switch (receivedCmd[0]) {
1292                                 case 0x02:
1293                                 case 0x03: {  // IBlock (command no CID)
1294                                         dynamic_response_info.response[0] = receivedCmd[0];
1295                                         dynamic_response_info.response[1] = 0x90;
1296                                         dynamic_response_info.response[2] = 0x00;
1297                                         dynamic_response_info.response_n = 3;
1298                                 } break;
1299                                 case 0x0B:
1300                                 case 0x0A: { // IBlock (command CID)
1301                                   dynamic_response_info.response[0] = receivedCmd[0];
1302                                   dynamic_response_info.response[1] = 0x00;
1303                                   dynamic_response_info.response[2] = 0x90;
1304                                   dynamic_response_info.response[3] = 0x00;
1305                                   dynamic_response_info.response_n = 4;
1306                                 } break;
1307
1308                                 case 0x1A:
1309                                 case 0x1B: { // Chaining command
1310                                   dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1);
1311                                   dynamic_response_info.response_n = 2;
1312                                 } break;
1313
1314                                 case 0xaa:
1315                                 case 0xbb: {
1316                                   dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11;
1317                                   dynamic_response_info.response_n = 2;
1318                                 } break;
1319
1320                                 case 0xBA: { // ping / pong
1321                                         dynamic_response_info.response[0] = 0xAB;
1322                                         dynamic_response_info.response[1] = 0x00;
1323                                         dynamic_response_info.response_n = 2;
1324                                 } break;
1325
1326                                 case 0xCA:
1327                                 case 0xC2: { // Readers sends deselect command
1328                                         dynamic_response_info.response[0] = 0xCA;
1329                                         dynamic_response_info.response[1] = 0x00;
1330                                         dynamic_response_info.response_n = 2;
1331                                 } break;
1332
1333                                 default: {
1334                                         // Never seen this command before
1335                                         LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1336                                         Dbprintf("Received unknown command (len=%d):",len);
1337                                         Dbhexdump(len,receivedCmd,false);
1338                                         // Do not respond
1339                                         dynamic_response_info.response_n = 0;
1340                                 } break;
1341                         }
1342
1343                         if (dynamic_response_info.response_n > 0) {
1344                                 // Copy the CID from the reader query
1345                                 dynamic_response_info.response[1] = receivedCmd[1];
1346
1347                                 // Add CRC bytes, always used in ISO 14443A-4 compliant cards
1348                                 AppendCrc14443a(dynamic_response_info.response,dynamic_response_info.response_n);
1349                                 dynamic_response_info.response_n += 2;
1350
1351                                 if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) {
1352                                         Dbprintf("Error preparing tag response");
1353                                         LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1354                                         break;
1355                                 }
1356                                 p_response = &dynamic_response_info;
1357                         }
1358                 }
1359
1360                 // Count number of wakeups received after a halt
1361                 if(order == 6 && lastorder == 5) { happened++; }
1362
1363                 // Count number of other messages after a halt
1364                 if(order != 6 && lastorder == 5) { happened2++; }
1365
1366                 if(cmdsRecvd > 999) {
1367                         DbpString("1000 commands later...");
1368                         break;
1369                 }
1370                 cmdsRecvd++;
1371
1372                 if (p_response != NULL) {
1373                         EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52);
1374                         // do the tracing for the previous reader request and this tag answer:
1375                         uint8_t par[MAX_PARITY_SIZE] = {0x00};
1376                         GetParity(p_response->response, p_response->response_n, par);
1377
1378                         EmLogTrace(Uart.output,
1379                                                 Uart.len,
1380                                                 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1381                                                 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1382                                                 Uart.parity,
1383                                                 p_response->response,
1384                                                 p_response->response_n,
1385                                                 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1386                                                 (LastTimeProxToAirStart + p_response->ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1387                                                 par);
1388                 }
1389
1390                 if (!tracing) {
1391                         Dbprintf("Trace Full. Simulation stopped.");
1392                         break;
1393                 }
1394         }
1395
1396         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
1397         set_tracing(FALSE);
1398         BigBuf_free_keep_EM();
1399         LED_A_OFF();
1400
1401         if (MF_DBGLEVEL >= 4){
1402                 Dbprintf("-[ Wake ups after halt [%d]", happened);
1403                 Dbprintf("-[ Messages after halt [%d]", happened2);
1404                 Dbprintf("-[ Num of received cmd [%d]", cmdsRecvd);
1405         }
1406 }
1407
1408
1409 // prepare a delayed transfer. This simply shifts ToSend[] by a number
1410 // of bits specified in the delay parameter.
1411 void PrepareDelayedTransfer(uint16_t delay)
1412 {
1413         delay &= 0x07;
1414         if (!delay) return;
1415
1416         uint8_t bitmask = 0;
1417         uint8_t bits_to_shift = 0;
1418         uint8_t bits_shifted = 0;
1419         uint16_t i = 0;
1420
1421         for (i = 0; i < delay; ++i)
1422                 bitmask |= (0x01 << i);
1423
1424         ToSend[++ToSendMax] = 0x00;
1425
1426         for (i = 0; i < ToSendMax; ++i) {
1427                         bits_to_shift = ToSend[i] & bitmask;
1428                         ToSend[i] = ToSend[i] >> delay;
1429                         ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay));
1430                         bits_shifted = bits_to_shift;
1431                 }
1432         }
1433
1434
1435 //-------------------------------------------------------------------------------------
1436 // Transmit the command (to the tag) that was placed in ToSend[].
1437 // Parameter timing:
1438 // if NULL: transfer at next possible time, taking into account
1439 //                      request guard time and frame delay time
1440 // if == 0:     transfer immediately and return time of transfer
1441 // if != 0: delay transfer until time specified
1442 //-------------------------------------------------------------------------------------
1443 static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing)
1444 {
1445         FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
1446
1447         uint32_t ThisTransferTime = 0;
1448
1449         if (timing) {
1450
1451                 if (*timing != 0)
1452                         // Delay transfer (fine tuning - up to 7 MF clock ticks)
1453                         PrepareDelayedTransfer(*timing & 0x00000007);
1454                 else
1455                         // Measure time
1456                         *timing = (GetCountSspClk() + 8) & 0xfffffff8;
1457
1458
1459                 if (MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8))
1460                         Dbprintf("TransmitFor14443a: Missed timing");
1461
1462                 // Delay transfer (multiple of 8 MF clock ticks)
1463                 while (GetCountSspClk() < (*timing & 0xfffffff8));
1464
1465                 LastTimeProxToAirStart = *timing;
1466         } else {
1467                 ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8);
1468
1469                 while(GetCountSspClk() < ThisTransferTime);
1470
1471                 LastTimeProxToAirStart = ThisTransferTime;
1472         }
1473
1474         // clear TXRDY
1475         AT91C_BASE_SSC->SSC_THR = SEC_Y;
1476
1477         uint16_t c = 0;
1478         for(;;) {
1479                 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1480                         AT91C_BASE_SSC->SSC_THR = cmd[c];
1481                         ++c;
1482                         if(c >= len)
1483                                 break;
1484                 }
1485         }
1486
1487         NextTransferTime = MAX(NextTransferTime, LastTimeProxToAirStart + REQUEST_GUARD_TIME);
1488 }
1489
1490
1491 //-----------------------------------------------------------------------------
1492 // Prepare reader command (in bits, support short frames) to send to FPGA
1493 //-----------------------------------------------------------------------------
1494 void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8_t *parity)
1495 {
1496         int i, j;
1497         int last = 0;
1498         uint8_t b;
1499
1500         ToSendReset();
1501
1502         // Start of Communication (Seq. Z)
1503         ToSend[++ToSendMax] = SEC_Z;
1504         LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1505
1506         size_t bytecount = nbytes(bits);
1507         // Generate send structure for the data bits
1508         for (i = 0; i < bytecount; i++) {
1509                 // Get the current byte to send
1510                 b = cmd[i];
1511                 size_t bitsleft = MIN((bits-(i*8)),8);
1512
1513                 for (j = 0; j < bitsleft; j++) {
1514                         if (b & 1) {
1515                                 // Sequence X
1516                                 ToSend[++ToSendMax] = SEC_X;
1517                                 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1518                                 last = 1;
1519                         } else {
1520                                 if (last == 0) {
1521                                 // Sequence Z
1522                                 ToSend[++ToSendMax] = SEC_Z;
1523                                 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1524                                 } else {
1525                                         // Sequence Y
1526                                         ToSend[++ToSendMax] = SEC_Y;
1527                                         last = 0;
1528                                 }
1529                         }
1530                         b >>= 1;
1531                 }
1532
1533                 // Only transmit parity bit if we transmitted a complete byte
1534                 if (j == 8 && parity != NULL) {
1535                         // Get the parity bit
1536                         if (parity[i>>3] & (0x80 >> (i&0x0007))) {
1537                                 // Sequence X
1538                                 ToSend[++ToSendMax] = SEC_X;
1539                                 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1540                                 last = 1;
1541                         } else {
1542                                 if (last == 0) {
1543                                         // Sequence Z
1544                                         ToSend[++ToSendMax] = SEC_Z;
1545                                         LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1546                                 } else {
1547                                         // Sequence Y
1548                                         ToSend[++ToSendMax] = SEC_Y;
1549                                         last = 0;
1550                                 }
1551                         }
1552                 }
1553         }
1554
1555         // End of Communication: Logic 0 followed by Sequence Y
1556         if (last == 0) {
1557                 // Sequence Z
1558                 ToSend[++ToSendMax] = SEC_Z;
1559                 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1560         } else {
1561                 // Sequence Y
1562                 ToSend[++ToSendMax] = SEC_Y;
1563                 last = 0;
1564         }
1565         ToSend[++ToSendMax] = SEC_Y;
1566
1567         // Convert to length of command:
1568         ++ToSendMax;
1569 }
1570
1571 //-----------------------------------------------------------------------------
1572 // Prepare reader command to send to FPGA
1573 //-----------------------------------------------------------------------------
1574 void CodeIso14443aAsReaderPar(const uint8_t *cmd, uint16_t len, const uint8_t *parity)
1575 {
1576   //CodeIso14443aBitsAsReaderPar(cmd, len*8, parity);
1577   CodeIso14443aBitsAsReaderPar(cmd, len<<3, parity);
1578 }
1579
1580
1581 //-----------------------------------------------------------------------------
1582 // Wait for commands from reader
1583 // Stop when button is pressed (return 1) or field was gone (return 2)
1584 // Or return 0 when command is captured
1585 //-----------------------------------------------------------------------------
1586 static int EmGetCmd(uint8_t *received, uint16_t *len, uint8_t *parity)
1587 {
1588         *len = 0;
1589
1590         uint32_t timer = 0, vtime = 0;
1591         int analogCnt = 0;
1592         int analogAVG = 0;
1593
1594         // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
1595         // only, since we are receiving, not transmitting).
1596         // Signal field is off with the appropriate LED
1597         LED_D_OFF();
1598         FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1599
1600         // Set ADC to read field strength
1601         AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST;
1602         AT91C_BASE_ADC->ADC_MR =
1603                                 ADC_MODE_PRESCALE(63) |
1604                                 ADC_MODE_STARTUP_TIME(1) |
1605                                 ADC_MODE_SAMPLE_HOLD_TIME(15);
1606         AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF);
1607         // start ADC
1608         AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1609
1610         // Now run a 'software UART' on the stream of incoming samples.
1611         UartInit(received, parity);
1612
1613         // Clear RXRDY:
1614     uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1615
1616         for(;;) {
1617                 WDT_HIT();
1618
1619                 if (BUTTON_PRESS()) return 1;
1620
1621                 // test if the field exists
1622                 if (AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ADC_CHAN_HF)) {
1623                         analogCnt++;
1624                         analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF];
1625                         AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1626                         if (analogCnt >= 32) {
1627                                 if ((MAX_ADC_HF_VOLTAGE * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) {
1628                                         vtime = GetTickCount();
1629                                         if (!timer) timer = vtime;
1630                                         // 50ms no field --> card to idle state
1631                                         if (vtime - timer > 50) return 2;
1632                                 } else
1633                                         if (timer) timer = 0;
1634                                 analogCnt = 0;
1635                                 analogAVG = 0;
1636                         }
1637                 }
1638
1639                 // receive and test the miller decoding
1640         if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1641             b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1642                         if(MillerDecoding(b, 0)) {
1643                                 *len = Uart.len;
1644                                 return 0;
1645                         }
1646         }
1647
1648         }
1649 }
1650
1651
1652 static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded)
1653 {
1654         uint8_t b;
1655         uint16_t i = 0;
1656         uint32_t ThisTransferTime;
1657
1658         // Modulate Manchester
1659         FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
1660
1661         // include correction bit if necessary
1662         if (Uart.parityBits & 0x01) {
1663                 correctionNeeded = TRUE;
1664         }
1665         if(correctionNeeded) {
1666                 // 1236, so correction bit needed
1667                 i = 0;
1668         } else {
1669                 i = 1;
1670         }
1671
1672         // clear receiving shift register and holding register
1673         while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1674         b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1675         while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1676         b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1677
1678         // wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line)
1679         for (uint16_t j = 0; j < 5; j++) {      // allow timeout - better late than never
1680                 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1681                 if (AT91C_BASE_SSC->SSC_RHR) break;
1682         }
1683
1684         while ((ThisTransferTime = GetCountSspClk()) & 0x00000007);
1685
1686         // Clear TXRDY:
1687         AT91C_BASE_SSC->SSC_THR = SEC_F;
1688
1689         // send cycle
1690         for(; i < respLen; ) {
1691                 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1692                         AT91C_BASE_SSC->SSC_THR = resp[i++];
1693                         FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1694                 }
1695
1696                 if(BUTTON_PRESS()) break;
1697         }
1698
1699         // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
1700         uint8_t fpga_queued_bits = FpgaSendQueueDelay >> 3;  // twich /8 ??   >>3,
1701         for (i = 0; i <= fpga_queued_bits/8 + 1; ) {
1702                 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1703                         AT91C_BASE_SSC->SSC_THR = SEC_F;
1704                         FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1705                         i++;
1706                 }
1707         }
1708
1709         LastTimeProxToAirStart = ThisTransferTime + (correctionNeeded?8:0);
1710
1711         return 0;
1712 }
1713
1714 int EmSend4bitEx(uint8_t resp, bool correctionNeeded){
1715         Code4bitAnswerAsTag(resp);
1716         int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1717         // do the tracing for the previous reader request and this tag answer:
1718         uint8_t par[1] = {0x00};
1719         GetParity(&resp, 1, par);
1720         EmLogTrace(Uart.output,
1721                                 Uart.len,
1722                                 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1723                                 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1724                                 Uart.parity,
1725                                 &resp,
1726                                 1,
1727                                 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1728                                 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1729                                 par);
1730         return res;
1731 }
1732
1733 int EmSend4bit(uint8_t resp){
1734         return EmSend4bitEx(resp, false);
1735 }
1736
1737 int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par){
1738         CodeIso14443aAsTagPar(resp, respLen, par);
1739         int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1740         // do the tracing for the previous reader request and this tag answer:
1741         EmLogTrace(Uart.output,
1742                                 Uart.len,
1743                                 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1744                                 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1745                                 Uart.parity,
1746                                 resp,
1747                                 respLen,
1748                                 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1749                                 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1750                                 par);
1751         return res;
1752 }
1753
1754 int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded){
1755         uint8_t par[MAX_PARITY_SIZE] = {0x00};
1756         GetParity(resp, respLen, par);
1757         return EmSendCmdExPar(resp, respLen, correctionNeeded, par);
1758 }
1759
1760 int EmSendCmd(uint8_t *resp, uint16_t respLen){
1761         uint8_t par[MAX_PARITY_SIZE] = {0x00};
1762         GetParity(resp, respLen, par);
1763         return EmSendCmdExPar(resp, respLen, false, par);
1764 }
1765
1766 int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par){
1767         return EmSendCmdExPar(resp, respLen, false, par);
1768 }
1769
1770 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
1771                                  uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity)
1772 {
1773         // we cannot exactly measure the end and start of a received command from reader. However we know that the delay from
1774         // end of the received command to start of the tag's (simulated by us) answer is n*128+20 or n*128+84 resp.
1775         // with n >= 9. The start of the tags answer can be measured and therefore the end of the received command be calculated:
1776         uint16_t reader_modlen = reader_EndTime - reader_StartTime;
1777         uint16_t approx_fdt = tag_StartTime - reader_EndTime;
1778         uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20;
1779         reader_EndTime = tag_StartTime - exact_fdt;
1780         reader_StartTime = reader_EndTime - reader_modlen;
1781
1782         if (!LogTrace(reader_data, reader_len, reader_StartTime, reader_EndTime, reader_Parity, TRUE))
1783                 return FALSE;
1784         else
1785                 return(!LogTrace(tag_data, tag_len, tag_StartTime, tag_EndTime, tag_Parity, FALSE));
1786
1787 }
1788
1789 //-----------------------------------------------------------------------------
1790 // Wait a certain time for tag response
1791 //  If a response is captured return TRUE
1792 //  If it takes too long return FALSE
1793 //-----------------------------------------------------------------------------
1794 static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receivedResponsePar, uint16_t offset)
1795 {
1796         uint32_t c = 0x00;
1797
1798         // Set FPGA mode to "reader listen mode", no modulation (listen
1799         // only, since we are receiving, not transmitting).
1800         // Signal field is on with the appropriate LED
1801         LED_D_ON();
1802         FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
1803
1804         // Now get the answer from the card
1805         DemodInit(receivedResponse, receivedResponsePar);
1806
1807         // clear RXRDY:
1808     uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1809
1810         for(;;) {
1811                 WDT_HIT();
1812
1813                 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1814                         b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1815                         if(ManchesterDecoding(b, offset, 0)) {
1816                                 NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD);
1817                                 return TRUE;
1818                         } else if (c++ > iso14a_timeout && Demod.state == DEMOD_UNSYNCD) {
1819                                 return FALSE;
1820                         }
1821                 }
1822         }
1823 }
1824
1825 void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t *timing)
1826 {
1827         CodeIso14443aBitsAsReaderPar(frame, bits, par);
1828
1829         // Send command to tag
1830         TransmitFor14443a(ToSend, ToSendMax, timing);
1831         if(trigger)
1832                 LED_A_ON();
1833
1834         // Log reader command in trace buffer
1835         //LogTrace(frame, nbytes(bits), LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_READER, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_READER, par, TRUE);
1836         LogTrace(frame, nbytes(bits), (LastTimeProxToAirStart<<4) + DELAY_ARM2AIR_AS_READER, ((LastTimeProxToAirStart + LastProxToAirDuration)<<4) + DELAY_ARM2AIR_AS_READER, par, TRUE);
1837 }
1838
1839 void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *timing)
1840 {
1841   //ReaderTransmitBitsPar(frame, len*8, par, timing);
1842   ReaderTransmitBitsPar(frame, len<<3, par, timing);
1843 }
1844
1845 void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing)
1846 {
1847   // Generate parity and redirect
1848   uint8_t par[MAX_PARITY_SIZE] = {0x00};
1849   //GetParity(frame, len/8, par);
1850   GetParity(frame, len >> 3, par);
1851   ReaderTransmitBitsPar(frame, len, par, timing);
1852 }
1853
1854 void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *timing)
1855 {
1856   // Generate parity and redirect
1857   uint8_t par[MAX_PARITY_SIZE] = {0x00};
1858   GetParity(frame, len, par);
1859   //ReaderTransmitBitsPar(frame, len*8, par, timing);
1860   ReaderTransmitBitsPar(frame, len<<3, par, timing);
1861 }
1862
1863 int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset, uint8_t *parity)
1864 {
1865         if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, offset))
1866                 return FALSE;
1867
1868         //LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1869         LogTrace(receivedAnswer, Demod.len, (Demod.startTime<<4) - DELAY_AIR2ARM_AS_READER, (Demod.endTime<<4) - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1870         return Demod.len;
1871 }
1872
1873 int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity)
1874 {
1875         if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, 0))
1876                 return FALSE;
1877
1878         //LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1879         LogTrace(receivedAnswer, Demod.len, (Demod.startTime<<4) - DELAY_AIR2ARM_AS_READER, (Demod.endTime<<4) - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1880         return Demod.len;
1881 }
1882
1883 // performs iso14443a anticollision (optional) and card select procedure
1884 // fills the uid and cuid pointer unless NULL
1885 // fills the card info record unless NULL
1886 // if anticollision is false, then the UID must be provided in uid_ptr[]
1887 // and num_cascades must be set (1: 4 Byte UID, 2: 7 Byte UID, 3: 10 Byte UID)
1888 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) {
1889         uint8_t wupa[]       = { 0x52 };  // 0x26 - REQA  0x52 - WAKE-UP
1890         uint8_t sel_all[]    = { 0x93,0x20 };
1891         uint8_t sel_uid[]    = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
1892         uint8_t rats[]       = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
1893         uint8_t resp[MAX_FRAME_SIZE] = {0}; // theoretically. A usual RATS will be much smaller
1894         uint8_t resp_par[MAX_PARITY_SIZE] = {0};
1895         byte_t uid_resp[4] = {0};
1896         size_t uid_resp_len = 0;
1897
1898         uint8_t sak = 0x04; // cascade uid
1899         int cascade_level = 0;
1900         int len;
1901
1902         // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
1903     ReaderTransmitBitsPar(wupa, 7, NULL, NULL);
1904
1905         // Receive the ATQA
1906         if(!ReaderReceive(resp, resp_par)) return 0;
1907
1908         if(p_hi14a_card) {
1909                 memcpy(p_hi14a_card->atqa, resp, 2);
1910                 p_hi14a_card->uidlen = 0;
1911                 memset(p_hi14a_card->uid,0,10);
1912         }
1913
1914         if (anticollision) {
1915                 // clear uid
1916                 if (uid_ptr)
1917                         memset(uid_ptr,0,10);
1918         }
1919
1920         // check for proprietary anticollision:
1921         if ((resp[0] & 0x1F) == 0) return 3;
1922
1923         // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
1924         // which case we need to make a cascade 2 request and select - this is a long UID
1925         // While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
1926         for(; sak & 0x04; cascade_level++) {
1927                 // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
1928                 sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
1929
1930                 if (anticollision) {
1931                 // SELECT_ALL
1932                         ReaderTransmit(sel_all, sizeof(sel_all), NULL);
1933                         if (!ReaderReceive(resp, resp_par)) return 0;
1934
1935                         if (Demod.collisionPos) {                       // we had a collision and need to construct the UID bit by bit
1936                                 memset(uid_resp, 0, 4);
1937                                 uint16_t uid_resp_bits = 0;
1938                                 uint16_t collision_answer_offset = 0;
1939                                 // anti-collision-loop:
1940                                 while (Demod.collisionPos) {
1941                                         Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos);
1942                                         for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) {      // add valid UID bits before collision point
1943                                                 uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01;
1944                                                 uid_resp[uid_resp_bits / 8] |= UIDbit << (uid_resp_bits % 8);
1945                                         }
1946                                         uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8);                                  // next time select the card(s) with a 1 in the collision position
1947                                         uid_resp_bits++;
1948                                         // construct anticollosion command:
1949                                         sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07);     // length of data in bytes and bits
1950                                         for (uint16_t i = 0; i <= uid_resp_bits/8; i++) {
1951                                                 sel_uid[2+i] = uid_resp[i];
1952                                         }
1953                                         collision_answer_offset = uid_resp_bits%8;
1954                                         ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL);
1955                                         if (!ReaderReceiveOffset(resp, collision_answer_offset, resp_par)) return 0;
1956                                 }
1957                                 // finally, add the last bits and BCC of the UID
1958                                 for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) {
1959                                         uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01;
1960                                         uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8);
1961                                 }
1962
1963                         } else {                // no collision, use the response to SELECT_ALL as current uid
1964                                 memcpy(uid_resp, resp, 4);
1965                         }
1966
1967                 } else {
1968                         if (cascade_level < num_cascades - 1) {
1969                                 uid_resp[0] = 0x88;
1970                                 memcpy(uid_resp+1, uid_ptr+cascade_level*3, 3);
1971                         } else {
1972                                 memcpy(uid_resp, uid_ptr+cascade_level*3, 4);
1973                         }
1974                 }
1975                 uid_resp_len = 4;
1976
1977                 // calculate crypto UID. Always use last 4 Bytes.
1978                 if(cuid_ptr)
1979                         *cuid_ptr = bytes_to_num(uid_resp, 4);
1980
1981                 // Construct SELECT UID command
1982                 sel_uid[1] = 0x70;                                                                                                      // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC)
1983                 memcpy(sel_uid+2, uid_resp, 4);                                                                         // the UID received during anticollision, or the provided UID
1984                 sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5];         // calculate and add BCC
1985                 AppendCrc14443a(sel_uid, 7);                                                                            // calculate and add CRC
1986                 ReaderTransmit(sel_uid, sizeof(sel_uid), NULL);
1987
1988                 // Receive the SAK
1989                 if (!ReaderReceive(resp, resp_par)) return 0;
1990
1991                 sak = resp[0];
1992
1993                 // Test if more parts of the uid are coming
1994                 if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) {
1995                         // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of:
1996                         // http://www.nxp.com/documents/application_note/AN10927.pdf
1997                         uid_resp[0] = uid_resp[1];
1998                         uid_resp[1] = uid_resp[2];
1999                         uid_resp[2] = uid_resp[3];
2000                         uid_resp_len = 3;
2001                 }
2002
2003                 if(uid_ptr && anticollision)
2004                         memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len);
2005
2006                 if(p_hi14a_card) {
2007                         memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
2008                         p_hi14a_card->uidlen += uid_resp_len;
2009                 }
2010         }
2011
2012         if(p_hi14a_card) {
2013                 p_hi14a_card->sak = sak;
2014                 p_hi14a_card->ats_len = 0;
2015         }
2016
2017         // non iso14443a compliant tag
2018         if( (sak & 0x20) == 0) return 2;
2019
2020         // Request for answer to select
2021         AppendCrc14443a(rats, 2);
2022         ReaderTransmit(rats, sizeof(rats), NULL);
2023
2024         if (!(len = ReaderReceive(resp, resp_par))) return 0;
2025
2026         if(p_hi14a_card) {
2027                 memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
2028                 p_hi14a_card->ats_len = len;
2029         }
2030
2031         // reset the PCB block number
2032         iso14_pcb_blocknum = 0;
2033
2034         // set default timeout based on ATS
2035         iso14a_set_ATS_timeout(resp);
2036
2037         return 1;
2038 }
2039
2040 void iso14443a_setup(uint8_t fpga_minor_mode) {
2041         FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
2042         // Set up the synchronous serial port
2043         FpgaSetupSsc();
2044         // connect Demodulated Signal to ADC:
2045         SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
2046
2047         // Signal field is on with the appropriate LED
2048         if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD
2049                 || fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN)
2050                 LED_D_ON();
2051         else
2052                 LED_D_OFF();
2053
2054         FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode);
2055
2056         DemodReset();
2057         UartReset();
2058
2059         iso14a_set_timeout(10*106); // 10ms default
2060
2061         // Start the timer
2062         StartCountSspClk();
2063
2064         NextTransferTime = 2*DELAY_ARM2AIR_AS_READER;
2065 }
2066
2067 int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data) {
2068         uint8_t parity[MAX_PARITY_SIZE] = {0x00};
2069         uint8_t real_cmd[cmd_len+4];
2070         real_cmd[0] = 0x0a; //I-Block
2071         // put block number into the PCB
2072         real_cmd[0] |= iso14_pcb_blocknum;
2073         real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards
2074         memcpy(real_cmd+2, cmd, cmd_len);
2075         AppendCrc14443a(real_cmd,cmd_len+2);
2076
2077         ReaderTransmit(real_cmd, cmd_len+4, NULL);
2078         size_t len = ReaderReceive(data, parity);
2079         uint8_t *data_bytes = (uint8_t *) data;
2080         if (!len)
2081                 return 0; //DATA LINK ERROR
2082         // if we received an I- or R(ACK)-Block with a block number equal to the
2083         // current block number, toggle the current block number
2084         else if (len >= 4 // PCB+CID+CRC = 4 bytes
2085                  && ((data_bytes[0] & 0xC0) == 0 // I-Block
2086                      || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0
2087                  && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers
2088         {
2089                 iso14_pcb_blocknum ^= 1;
2090         }
2091
2092         return len;
2093 }
2094
2095 //-----------------------------------------------------------------------------
2096 // Read an ISO 14443a tag. Send out commands and store answers.
2097 //
2098 //-----------------------------------------------------------------------------
2099 void ReaderIso14443a(UsbCommand *c)
2100 {
2101         iso14a_command_t param = c->arg[0];
2102         uint8_t *cmd = c->d.asBytes;
2103         size_t len = c->arg[1] & 0xffff;
2104         size_t lenbits = c->arg[1] >> 16;
2105         uint32_t timeout = c->arg[2];
2106         uint32_t arg0 = 0;
2107         byte_t buf[USB_CMD_DATA_SIZE] = {0x00};
2108         uint8_t par[MAX_PARITY_SIZE] = {0x00};
2109
2110         if (param & ISO14A_CONNECT)
2111                 clear_trace();
2112
2113         set_tracing(TRUE);
2114
2115         if (param & ISO14A_REQUEST_TRIGGER)
2116                 iso14a_set_trigger(TRUE);
2117
2118         if (param & ISO14A_CONNECT) {
2119                 iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN);
2120                 if(!(param & ISO14A_NO_SELECT)) {
2121                         iso14a_card_select_t *card = (iso14a_card_select_t*)buf;
2122                         arg0 = iso14443a_select_card(NULL,card,NULL, true, 0);
2123                         cmd_send(CMD_ACK,arg0,card->uidlen,0,buf,sizeof(iso14a_card_select_t));
2124                         // if it fails,  the cmdhf14a.c client quites.. however this one still executes.
2125                         if ( arg0 == 0 ) return;
2126                 }
2127         }
2128
2129         if (param & ISO14A_SET_TIMEOUT)
2130                 iso14a_set_timeout(timeout);
2131
2132         if (param & ISO14A_APDU) {
2133                 arg0 = iso14_apdu(cmd, len, buf);
2134                 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
2135         }
2136
2137         if (param & ISO14A_RAW) {
2138                 if(param & ISO14A_APPEND_CRC) {
2139                         if(param & ISO14A_TOPAZMODE) {
2140                                 AppendCrc14443b(cmd,len);
2141                         } else {
2142                                 AppendCrc14443a(cmd,len);
2143                         }
2144                         len += 2;
2145                         if (lenbits) lenbits += 16;
2146                 }
2147                 if(lenbits>0) {                         // want to send a specific number of bits (e.g. short commands)
2148                         if(param & ISO14A_TOPAZMODE) {
2149                                 int bits_to_send = lenbits;
2150                                 uint16_t i = 0;
2151                                 ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 7), NULL, NULL);             // first byte is always short (7bits) and no parity
2152                                 bits_to_send -= 7;
2153                                 while (bits_to_send > 0) {
2154                                         ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 8), NULL, NULL);     // following bytes are 8 bit and no parity
2155                                         bits_to_send -= 8;
2156                                 }
2157                         } else {
2158                         GetParity(cmd, lenbits/8, par);
2159                                 ReaderTransmitBitsPar(cmd, lenbits, par, NULL);                                                 // bytes are 8 bit with odd parity
2160                         }
2161                 } else {                                        // want to send complete bytes only
2162                         if(param & ISO14A_TOPAZMODE) {
2163                                 uint16_t i = 0;
2164                                 ReaderTransmitBitsPar(&cmd[i++], 7, NULL, NULL);                                                // first byte: 7 bits, no paritiy
2165                                 while (i < len) {
2166                                         ReaderTransmitBitsPar(&cmd[i++], 8, NULL, NULL);                                        // following bytes: 8 bits, no paritiy
2167                                 }
2168                 } else {
2169                                 ReaderTransmit(cmd,len, NULL);                                                                                  // 8 bits, odd parity
2170                         }
2171                 }
2172                 arg0 = ReaderReceive(buf, par);
2173                 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
2174         }
2175
2176         if (param & ISO14A_REQUEST_TRIGGER)
2177                 iso14a_set_trigger(FALSE);
2178
2179
2180         if (param & ISO14A_NO_DISCONNECT)
2181                 return;
2182
2183         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2184         set_tracing(FALSE);
2185         LEDsoff();
2186 }
2187
2188
2189 // Determine the distance between two nonces.
2190 // Assume that the difference is small, but we don't know which is first.
2191 // Therefore try in alternating directions.
2192 int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
2193
2194         if (nt1 == nt2) return 0;
2195
2196         uint16_t i;
2197         uint32_t nttmp1 = nt1;
2198         uint32_t nttmp2 = nt2;
2199
2200         for (i = 1; i < 0xFFFF; i += 8) {
2201                 nttmp1 = prng_successor_one(nttmp1); if (nttmp1 == nt2) return i;
2202                 nttmp2 = prng_successor_one(nttmp2); if (nttmp2 == nt1) return -i;
2203
2204                 nttmp1 = prng_successor_one(nttmp1); if (nttmp1 == nt2) return i+1;
2205                 nttmp2 = prng_successor_one(nttmp2); if (nttmp2 == nt1) return -i-1;
2206
2207                 nttmp1 = prng_successor_one(nttmp1); if (nttmp1 == nt2) return i+2;
2208                 nttmp2 = prng_successor_one(nttmp2); if (nttmp2 == nt1) return -i-2;
2209
2210                 nttmp1 = prng_successor_one(nttmp1); if (nttmp1 == nt2) return i+3;
2211                 nttmp2 = prng_successor_one(nttmp2); if (nttmp2 == nt1) return -i-3;
2212
2213                 nttmp1 = prng_successor_one(nttmp1); if (nttmp1 == nt2) return i+4;
2214                 nttmp2 = prng_successor_one(nttmp2); if (nttmp2 == nt1) return -i-4;
2215
2216                 nttmp1 = prng_successor_one(nttmp1); if (nttmp1 == nt2) return i+5;
2217                 nttmp2 = prng_successor_one(nttmp2); if (nttmp2 == nt1) return -i-5;
2218
2219                 nttmp1 = prng_successor_one(nttmp1); if (nttmp1 == nt2) return i+6;
2220                 nttmp2 = prng_successor_one(nttmp2); if (nttmp2 == nt1) return -i-6;
2221
2222                 nttmp1 = prng_successor_one(nttmp1); if (nttmp1 == nt2) return i+7;
2223                 nttmp2 = prng_successor_one(nttmp2); if (nttmp2 == nt1) return -i-7;
2224 /*
2225                 if ( prng_successor(nttmp1, i) == nt2) return i;
2226                 if ( prng_successor(nttmp2, i) == nt1) return -i;
2227
2228                 if ( prng_successor(nttmp1, i+2) == nt2) return i+2;
2229                 if ( prng_successor(nttmp2, i+2) == nt1) return -(i+2);
2230
2231                 if ( prng_successor(nttmp1, i+3) == nt2) return i+3;
2232                 if ( prng_successor(nttmp2, i+3) == nt1) return -(i+3);
2233
2234                 if ( prng_successor(nttmp1, i+4) == nt2) return i+4;
2235                 if ( prng_successor(nttmp2, i+4) == nt1) return -(i+4);
2236
2237                 if ( prng_successor(nttmp1, i+5) == nt2) return i+5;
2238                 if ( prng_successor(nttmp2, i+5) == nt1) return -(i+5);
2239
2240                 if ( prng_successor(nttmp1, i+6) == nt2) return i+6;
2241                 if ( prng_successor(nttmp2, i+6) == nt1) return -(i+6);
2242
2243                 if ( prng_successor(nttmp1, i+7) == nt2) return i+7;
2244                 if ( prng_successor(nttmp2, i+7) == nt1) return -(i+7);
2245 */
2246         }
2247
2248         return(-99999); // either nt1 or nt2 are invalid nonces
2249 }
2250
2251
2252 //-----------------------------------------------------------------------------
2253 // Recover several bits of the cypher stream. This implements (first stages of)
2254 // the algorithm described in "The Dark Side of Security by Obscurity and
2255 // Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime"
2256 // (article by Nicolas T. Courtois, 2009)
2257 //-----------------------------------------------------------------------------
2258 void ReaderMifare(bool first_try, uint8_t block )
2259 {
2260         // Mifare AUTH
2261         //uint8_t mf_auth[]    = { 0x60,0x00,0xf5,0x7b };
2262         //uint8_t mf_auth[]    = { 0x60,0x05, 0x58, 0x2c };
2263         uint8_t mf_auth[]       = { 0x60,0x00, 0x00, 0x00 };
2264         uint8_t mf_nr_ar[]      = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
2265         uint8_t uid[10]         = {0,0,0,0,0,0,0,0,0,0};
2266         uint8_t par_list[8]     = {0,0,0,0,0,0,0,0};
2267         uint8_t ks_list[8]      = {0,0,0,0,0,0,0,0};
2268         uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE] = {0x00};
2269         uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE] = {0x00};
2270         uint8_t par[1] = {0};   // maximum 8 Bytes to be sent here, 1 byte parity is therefore enough
2271
2272         mf_auth[1] = block;
2273         AppendCrc14443a(mf_auth, 2);
2274
2275         byte_t nt_diff = 0;
2276
2277         uint32_t nt = 0;
2278         uint32_t previous_nt = 0;
2279         uint32_t halt_time = 0;
2280         uint32_t cuid = 0;
2281
2282         int catch_up_cycles = 0;
2283         int last_catch_up = 0;
2284         int isOK = 0;
2285
2286         uint16_t elapsed_prng_sequences = 1;
2287         uint16_t consecutive_resyncs = 0;
2288         uint16_t unexpected_random = 0;
2289         uint16_t sync_tries = 0;
2290         uint16_t strategy = 0;
2291
2292         static uint32_t nt_attacked = 0;
2293         static uint32_t sync_time = 0;
2294         static int32_t sync_cycles = 0;
2295         static uint8_t par_low = 0;
2296         static uint8_t mf_nr_ar3 = 0;
2297
2298         #define PRNG_SEQUENCE_LENGTH    (1 << 16)
2299         #define MAX_UNEXPECTED_RANDOM   4               // maximum number of unexpected (i.e. real) random numbers when trying to sync. Then give up.
2300         #define MAX_SYNC_TRIES          32
2301         #define MAX_STRATEGY            3
2302
2303         // free eventually allocated BigBuf memory
2304         BigBuf_free(); BigBuf_Clear_ext(false);
2305
2306         clear_trace();
2307         set_tracing(TRUE);
2308
2309         LED_A_ON();
2310
2311         if (first_try)
2312                 iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
2313
2314         if (first_try) {
2315                 sync_time = GetCountSspClk() & 0xfffffff8;
2316                 sync_cycles = PRNG_SEQUENCE_LENGTH + 1100; //65536;     //0x10000                       // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
2317                 mf_nr_ar3 = 0;
2318                 nt_attacked = 0;
2319
2320         } else {
2321                 // we were unsuccessful on a previous call.
2322                 // Try another READER nonce (first 3 parity bits remain the same)
2323                 ++mf_nr_ar3;
2324                 mf_nr_ar[3] = mf_nr_ar3;
2325                 par[0] = par_low;
2326         }
2327
2328                 LED_A_ON();
2329         LED_C_ON();
2330         for(uint16_t i = 0; TRUE; ++i) {
2331
2332                 WDT_HIT();
2333
2334                 // Test if the action was cancelled
2335                 if(BUTTON_PRESS()) {
2336                         isOK = -1;
2337                         break;
2338                 }
2339
2340                 if (strategy == 2) {
2341                         // test with additional halt command
2342                         halt_time = 0;
2343                         int len = mifare_sendcmd_short(NULL, false, 0x50, 0x00, receivedAnswer, receivedAnswerPar, &halt_time);
2344
2345                         if (len && MF_DBGLEVEL >= 3)
2346                                 Dbprintf("Unexpected response of %d bytes to halt command.", len);
2347                 }
2348
2349                 if (strategy == 3) {
2350                         // test with FPGA power off/on
2351                         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2352                         SpinDelay(200);
2353                         iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
2354                         SpinDelay(100);
2355                         sync_time = GetCountSspClk() & 0xfffffff8;
2356                         WDT_HIT();
2357                 }
2358
2359                 if (!iso14443a_select_card(uid, NULL,  &cuid, true, 0)) {
2360                         if (MF_DBGLEVEL >= 2) Dbprintf("Mifare: Can't select card\n");
2361                         continue;
2362                 }
2363
2364                 // Sending timeslot of ISO14443a frame
2365
2366                 sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
2367                 catch_up_cycles = 0;
2368
2369                 //catch_up_cycles = 0;
2370
2371                 // if we missed the sync time already, advance to the next nonce repeat
2372                 while(GetCountSspClk() > sync_time) {
2373                         ++elapsed_prng_sequences;
2374                         sync_time = (sync_time & 0xfffffff8) + sync_cycles;
2375                 }
2376                 // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked)
2377                 ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
2378
2379                 // Receive the (4 Byte) "random" nonce
2380                 if (!ReaderReceive(receivedAnswer, receivedAnswerPar))
2381                         continue;
2382
2383                 // Transmit reader nonce with fake par
2384                 ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
2385
2386                 previous_nt = nt;
2387                 nt = bytes_to_num(receivedAnswer, 4);
2388
2389                 if (first_try && previous_nt && !nt_attacked) { // we didn't calibrate our clock yet
2390                         int nt_distance = dist_nt(previous_nt, nt);
2391                         if (nt_distance == 0) {
2392                                 nt_attacked = nt;
2393                         } else {
2394                                 if (nt_distance == -99999) { // invalid nonce received
2395                                         unexpected_random++;
2396                                         if (unexpected_random > MAX_UNEXPECTED_RANDOM) {
2397                                                 isOK = -3;              // Card has an unpredictable PRNG. Give up
2398                                                 break;
2399                                         } else {
2400                                                 continue;               // continue trying...
2401                                         }
2402                                 }
2403
2404                                 if (++sync_tries > MAX_SYNC_TRIES) {
2405                                         if (strategy > MAX_STRATEGY || MF_DBGLEVEL < 3) {
2406                                                 isOK = -4;                      // Card's PRNG runs at an unexpected frequency or resets unexpectedly
2407                                                 break;
2408                                         } else {
2409                                                 continue;
2410                                 }
2411                                 }
2412
2413                                 sync_cycles = (sync_cycles - nt_distance)/elapsed_prng_sequences;
2414                                 if (sync_cycles <= 0)
2415                                         sync_cycles += PRNG_SEQUENCE_LENGTH;
2416
2417                                 if (MF_DBGLEVEL >= 3)
2418                                         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);
2419
2420                                 continue;
2421                         }
2422                 }
2423
2424                 if ((nt != nt_attacked) && nt_attacked) {       // we somehow lost sync. Try to catch up again...
2425
2426                         catch_up_cycles = -dist_nt(nt_attacked, nt);
2427                         if (catch_up_cycles == 99999) {                 // invalid nonce received. Don't resync on that one.
2428                                 catch_up_cycles = 0;
2429                                 continue;
2430                         }
2431
2432                         // average?
2433                         catch_up_cycles /= elapsed_prng_sequences;
2434
2435                         if (catch_up_cycles == last_catch_up) {
2436                                 ++consecutive_resyncs;
2437                         } else {
2438                                 last_catch_up = catch_up_cycles;
2439                             consecutive_resyncs = 0;
2440                         }
2441
2442                         if (consecutive_resyncs < 3) {
2443                                 if (MF_DBGLEVEL >= 3)
2444                                         Dbprintf("Lost sync in cycle %d. nt_distance=%d. Consecutive Resyncs = %d. Trying one time catch up...\n", i, -catch_up_cycles, consecutive_resyncs);
2445                         } else {
2446                                 sync_cycles += catch_up_cycles;
2447
2448                                 if (MF_DBGLEVEL >= 3)
2449                                         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);
2450
2451                                 last_catch_up = 0;
2452                                 catch_up_cycles = 0;
2453                                 consecutive_resyncs = 0;
2454                         }
2455                         continue;
2456                 }
2457
2458                 // Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
2459                 if (ReaderReceive(receivedAnswer, receivedAnswerPar)) {
2460                         catch_up_cycles = 8;    // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
2461
2462                         if (nt_diff == 0)
2463                                 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
2464
2465                         par_list[nt_diff] = SwapBits(par[0], 8);
2466                         ks_list[nt_diff] = receivedAnswer[0] ^ 0x05;
2467
2468                         // Test if the information is complete
2469                         if (nt_diff == 0x07) {
2470                                 isOK = 1;
2471                                 break;
2472                         }
2473
2474                         nt_diff = (nt_diff + 1) & 0x07;
2475                         mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
2476                         par[0] = par_low;
2477
2478                 } else {
2479                         // No NACK.
2480                         if (nt_diff == 0 && first_try) {
2481                                 par[0]++;
2482                                 if (par[0] == 0x00) {   // tried all 256 possible parities without success. Card doesn't send NACK.
2483                                         isOK = -2;
2484                                         break;
2485                                 }
2486                         } else {
2487                                 // Why this?
2488                                 par[0] = ((par[0] & 0x1F) + 1) | par_low;
2489                         }
2490                 }
2491
2492                 consecutive_resyncs = 0;
2493         }
2494
2495         mf_nr_ar[3] &= 0x1F;
2496
2497         WDT_HIT();
2498
2499         // reset sync_time.
2500         if ( isOK == 1) {
2501                 sync_time =     0;
2502                 sync_cycles = 0;
2503                 mf_nr_ar3 = 0;
2504                 nt_attacked = 0;
2505                 par[0] = 0;
2506         }
2507
2508         uint8_t buf[28] = {0x00};
2509         num_to_bytes(cuid, 4, buf);
2510         num_to_bytes(nt, 4, buf + 4);
2511         memcpy(buf + 8,  par_list, 8);
2512         memcpy(buf + 16, ks_list, 8);
2513         memcpy(buf + 24, mf_nr_ar, 4);
2514
2515         cmd_send(CMD_ACK,isOK,0,0,buf,28);
2516
2517         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2518         LEDsoff();
2519         set_tracing(FALSE);
2520 }
2521
2522 /**
2523   *MIFARE 1K simulate.
2524   *
2525   *@param flags :
2526   *     FLAG_INTERACTIVE - In interactive mode, we are expected to finish the operation with an ACK
2527   * 4B_FLAG_UID_IN_DATA - means that there is a 4-byte UID in the data-section, we're expected to use that
2528   * 7B_FLAG_UID_IN_DATA - means that there is a 7-byte UID in the data-section, we're expected to use that
2529   *     FLAG_NR_AR_ATTACK  - means we should collect NR_AR responses for bruteforcing later
2530   *@param exitAfterNReads, exit simulation after n blocks have been read, 0 is inifite
2531   */
2532 void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *datain)
2533 {
2534         int cardSTATE = MFEMUL_NOFIELD;
2535         int _7BUID = 0;
2536         int vHf = 0;    // in mV
2537         int res;
2538         uint32_t selTimer = 0;
2539         uint32_t authTimer = 0;
2540         uint16_t len = 0;
2541         uint8_t cardWRBL = 0;
2542         uint8_t cardAUTHSC = 0;
2543         uint8_t cardAUTHKEY = 0xff;  // no authentication
2544 //      uint32_t cardRr = 0;
2545         uint32_t cuid = 0;
2546         //uint32_t rn_enc = 0;
2547         uint32_t ans = 0;
2548         uint32_t cardINTREG = 0;
2549         uint8_t cardINTBLOCK = 0;
2550         struct Crypto1State mpcs = {0, 0};
2551         struct Crypto1State *pcs;
2552         pcs = &mpcs;
2553         uint32_t numReads = 0;//Counts numer of times reader read a block
2554         uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE] = {0x00};
2555         uint8_t receivedCmd_par[MAX_MIFARE_PARITY_SIZE] = {0x00};
2556         uint8_t response[MAX_MIFARE_FRAME_SIZE] = {0x00};
2557         uint8_t response_par[MAX_MIFARE_PARITY_SIZE] = {0x00};
2558
2559         uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID
2560         uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2561         uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; // !!!
2562         uint8_t rSAK[] = {0x08, 0xb6, 0xdd}; // Mifare Classic
2563         //uint8_t rSAK[] = {0x09, 0x3f, 0xcc };  // Mifare Mini
2564         uint8_t rSAK1[] = {0x04, 0xda, 0x17};
2565
2566         //uint8_t rAUTH_NT[] = {0x01, 0x01, 0x01, 0x01};
2567         uint8_t rAUTH_NT[] = {0x55, 0x41, 0x49, 0x92};
2568         uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
2569
2570         //Here, we collect UID1,UID2,NT,AR,NR,0,0,NT2,AR2,NR2
2571         // This can be used in a reader-only attack.
2572         // (it can also be retrieved via 'hf 14a list', but hey...
2573         uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0,0,0};
2574         uint8_t ar_nr_collected = 0;
2575
2576         // Authenticate response - nonce
2577         uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
2578
2579         //-- Determine the UID
2580         // Can be set from emulator memory, incoming data
2581         // and can be 7 or 4 bytes long
2582         if (flags & FLAG_4B_UID_IN_DATA)
2583         {
2584                 // 4B uid comes from data-portion of packet
2585                 memcpy(rUIDBCC1,datain,4);
2586                 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2587
2588         } else if (flags & FLAG_7B_UID_IN_DATA) {
2589                 // 7B uid comes from data-portion of packet
2590                 memcpy(&rUIDBCC1[1],datain,3);
2591                 memcpy(rUIDBCC2, datain+3, 4);
2592                 _7BUID = true;
2593         } else {
2594                 // get UID from emul memory
2595                 emlGetMemBt(receivedCmd, 7, 1);
2596                 _7BUID = !(receivedCmd[0] == 0x00);
2597                 if (!_7BUID) {                     // ---------- 4BUID
2598                         emlGetMemBt(rUIDBCC1, 0, 4);
2599                 } else {                           // ---------- 7BUID
2600                         emlGetMemBt(&rUIDBCC1[1], 0, 3);
2601                         emlGetMemBt(rUIDBCC2, 3, 4);
2602                 }
2603         }
2604
2605         // save uid.
2606         ar_nr_responses[0*5]   = bytes_to_num(rUIDBCC1+1, 3);
2607         if ( _7BUID )
2608                 ar_nr_responses[0*5+1] = bytes_to_num(rUIDBCC2, 4);
2609
2610         /*
2611          * Regardless of what method was used to set the UID, set fifth byte and modify
2612          * the ATQA for 4 or 7-byte UID
2613          */
2614         rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2615         if (_7BUID) {
2616                 rATQA[0] = 0x44;
2617                 rUIDBCC1[0] = 0x88;
2618                 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2619                 rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
2620         }
2621
2622         if (MF_DBGLEVEL >= 1)   {
2623                 if (!_7BUID) {
2624                         Dbprintf("4B UID: %02x%02x%02x%02x",
2625                                 rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3]);
2626                 } else {
2627                         Dbprintf("7B UID: (%02x)%02x%02x%02x%02x%02x%02x%02x",
2628                                 rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3],
2629                                 rUIDBCC2[0], rUIDBCC2[1] ,rUIDBCC2[2], rUIDBCC2[3]);
2630                 }
2631         }
2632
2633         // We need to listen to the high-frequency, peak-detected path.
2634         iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
2635
2636         // free eventually allocated BigBuf memory but keep Emulator Memory
2637         BigBuf_free_keep_EM();
2638
2639         // clear trace
2640         clear_trace();
2641         set_tracing(TRUE);
2642
2643
2644         bool finished = FALSE;
2645         while (!BUTTON_PRESS() && !finished && !usb_poll_validate_length()) {
2646                 WDT_HIT();
2647
2648                 // find reader field
2649                 if (cardSTATE == MFEMUL_NOFIELD) {
2650                         vHf = (MAX_ADC_HF_VOLTAGE * AvgAdc(ADC_CHAN_HF)) >> 10;
2651                         if (vHf > MF_MINFIELDV) {
2652                                 cardSTATE_TO_IDLE();
2653                                 LED_A_ON();
2654                         }
2655                 }
2656                 if(cardSTATE == MFEMUL_NOFIELD) continue;
2657
2658                 //Now, get data
2659                 res = EmGetCmd(receivedCmd, &len, receivedCmd_par);
2660                 if (res == 2) { //Field is off!
2661                         cardSTATE = MFEMUL_NOFIELD;
2662                         LEDsoff();
2663                         continue;
2664                 } else if (res == 1) {
2665                         break;  //return value 1 means button press
2666                 }
2667
2668                 // REQ or WUP request in ANY state and WUP in HALTED state
2669                 if (len == 1 && ((receivedCmd[0] == 0x26 && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == 0x52)) {
2670                         selTimer = GetTickCount();
2671                         EmSendCmdEx(rATQA, sizeof(rATQA), (receivedCmd[0] == 0x52));
2672                         cardSTATE = MFEMUL_SELECT1;
2673
2674                         // init crypto block
2675                         LED_B_OFF();
2676                         LED_C_OFF();
2677                         crypto1_destroy(pcs);
2678                         cardAUTHKEY = 0xff;
2679                         continue;
2680                 }
2681
2682                 switch (cardSTATE) {
2683                         case MFEMUL_NOFIELD:
2684                         case MFEMUL_HALTED:
2685                         case MFEMUL_IDLE:{
2686                                 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2687                                 break;
2688                         }
2689                         case MFEMUL_SELECT1:{
2690                                 // select all
2691                                 if (len == 2 && (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x20)) {
2692                                         if (MF_DBGLEVEL >= 4)   Dbprintf("SELECT ALL received");
2693                                         EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1));
2694                                         break;
2695                                 }
2696
2697                                 if (MF_DBGLEVEL >= 4 && len == 9 && receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 )
2698                                 {
2699                                         Dbprintf("SELECT %02x%02x%02x%02x received",receivedCmd[2],receivedCmd[3],receivedCmd[4],receivedCmd[5]);
2700                                 }
2701                                 // select card
2702                                 if (len == 9 &&
2703                                                 (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
2704                                         EmSendCmd(_7BUID?rSAK1:rSAK, _7BUID?sizeof(rSAK1):sizeof(rSAK));
2705                                         cuid = bytes_to_num(rUIDBCC1, 4);
2706                                         if (!_7BUID) {
2707                                                 cardSTATE = MFEMUL_WORK;
2708                                                 LED_B_ON();
2709                                                 if (MF_DBGLEVEL >= 4)   Dbprintf("--> WORK. anticol1 time: %d", GetTickCount() - selTimer);
2710                                                 break;
2711                                         } else {
2712                                                 cardSTATE = MFEMUL_SELECT2;
2713                                         }
2714                                 }
2715                                 break;
2716                         }
2717                         case MFEMUL_AUTH1:{
2718                                 if( len != 8) {
2719                                         cardSTATE_TO_IDLE();
2720                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2721                                         break;
2722                                 }
2723
2724                                 uint32_t ar = bytes_to_num(receivedCmd, 4);
2725                                 uint32_t nr = bytes_to_num(&receivedCmd[4], 4);
2726
2727                                 //Collect AR/NR
2728                                 //if(ar_nr_collected < 2 && cardAUTHSC == 2){
2729                                 if(ar_nr_collected < 2) {
2730                                         if(ar_nr_responses[2] != ar) {
2731                                                 // Avoid duplicates... probably not necessary, ar should vary.
2732                                                 //ar_nr_responses[ar_nr_collected*5]   = 0;
2733                                                 //ar_nr_responses[ar_nr_collected*5+1] = 0;
2734                                                 ar_nr_responses[ar_nr_collected*5+2] = nonce;
2735                                                 ar_nr_responses[ar_nr_collected*5+3] = nr;
2736                                                 ar_nr_responses[ar_nr_collected*5+4] = ar;
2737                                                 ar_nr_collected++;
2738                                         }
2739                                         // Interactive mode flag, means we need to send ACK
2740                                         if(flags & FLAG_INTERACTIVE && ar_nr_collected == 2)
2741                                                 finished = true;
2742                                 }
2743
2744                                 // --- crypto
2745                                 //crypto1_word(pcs, ar , 1);
2746                                 //cardRr = nr ^ crypto1_word(pcs, 0, 0);
2747
2748                                 //test if auth OK
2749                                 //if (cardRr != prng_successor(nonce, 64)){
2750
2751                                         //if (MF_DBGLEVEL >= 4) Dbprintf("AUTH FAILED for sector %d with key %c. cardRr=%08x, succ=%08x",
2752                                         //      cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
2753                                         //              cardRr, prng_successor(nonce, 64));
2754                                         // Shouldn't we respond anything here?
2755                                         // Right now, we don't nack or anything, which causes the
2756                                         // reader to do a WUPA after a while. /Martin
2757                                         // -- which is the correct response. /piwi
2758                                         //cardSTATE_TO_IDLE();
2759                                         //LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2760                                         //break;
2761                                 //}
2762
2763                                 ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0);
2764
2765                                 num_to_bytes(ans, 4, rAUTH_AT);
2766                                 // --- crypto
2767                                 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2768                                 LED_C_ON();
2769                                 cardSTATE = MFEMUL_WORK;
2770                                 if (MF_DBGLEVEL >= 4) {
2771                                         Dbprintf("AUTH COMPLETED for sector %d with key %c. time=%d",
2772                                                 cardAUTHSC,
2773                                                 cardAUTHKEY == 0 ? 'A' : 'B',
2774                                                 GetTickCount() - authTimer
2775                                         );
2776                                 }
2777                                 break;
2778                         }
2779                         case MFEMUL_SELECT2:{
2780                                 if (!len) {
2781                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2782                                         break;
2783                                 }
2784                                 if (len == 2 && (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x20)) {
2785                                         EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2));
2786                                         break;
2787                                 }
2788
2789                                 // select 2 card
2790                                 if (len == 9 &&
2791                                                 (receivedCmd[0] == 0x95 &&
2792                                                  receivedCmd[1] == 0x70 &&
2793                                                  memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0) ) {
2794                                         EmSendCmd(rSAK, sizeof(rSAK));
2795                                         cuid = bytes_to_num(rUIDBCC2, 4);
2796                                         cardSTATE = MFEMUL_WORK;
2797                                         LED_B_ON();
2798                                         if (MF_DBGLEVEL >= 4)   Dbprintf("--> WORK. anticol2 time: %d", GetTickCount() - selTimer);
2799                                         break;
2800                                 }
2801
2802                                 // i guess there is a command). go into the work state.
2803                                 if (len != 4) {
2804                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2805                                         break;
2806                                 }
2807                                 cardSTATE = MFEMUL_WORK;
2808                                 //goto lbWORK;
2809                                 //intentional fall-through to the next case-stmt
2810                         }
2811
2812                         case MFEMUL_WORK:{
2813                                 if (len == 0) {
2814                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2815                                         break;
2816                                 }
2817
2818                                 bool encrypted_data = (cardAUTHKEY != 0xFF) ;
2819
2820                                 // decrypt seqence
2821                                 if(encrypted_data)
2822                                         mf_crypto1_decrypt(pcs, receivedCmd, len);
2823
2824                                 if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) {
2825                                         authTimer = GetTickCount();
2826                                         cardAUTHSC = receivedCmd[1] / 4;  // received block num
2827                                         cardAUTHKEY = receivedCmd[0] - 0x60;
2828                                         crypto1_destroy(pcs);//Added by martin
2829                                         crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
2830
2831                                         if (!encrypted_data) { // first authentication
2832                                                 if (MF_DBGLEVEL >= 4) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY  );
2833
2834                                                 crypto1_word(pcs, cuid ^ nonce, 0);//Update crypto state
2835                                                 num_to_bytes(nonce, 4, rAUTH_AT); // Send nonce
2836                                         } else { // nested authentication
2837                                                 if (MF_DBGLEVEL >= 4) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2838                                                 ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0);
2839                                                 num_to_bytes(ans, 4, rAUTH_AT);
2840                                         }
2841
2842                                         EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2843                                         //Dbprintf("Sending rAUTH %02x%02x%02x%02x", rAUTH_AT[0],rAUTH_AT[1],rAUTH_AT[2],rAUTH_AT[3]);
2844                                         cardSTATE = MFEMUL_AUTH1;
2845                                         break;
2846                                 }
2847
2848                                 // rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued
2849                                 // BUT... ACK --> NACK
2850                                 if (len == 1 && receivedCmd[0] == CARD_ACK) {
2851                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2852                                         break;
2853                                 }
2854
2855                                 // rule 12 of 7.5.3. in ISO 14443-4. R(NAK) --> R(ACK)
2856                                 if (len == 1 && receivedCmd[0] == CARD_NACK_NA) {
2857                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2858                                         break;
2859                                 }
2860
2861                                 if(len != 4) {
2862                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2863                                         break;
2864                                 }
2865
2866                                 if(receivedCmd[0] == 0x30 // read block
2867                                                 || receivedCmd[0] == 0xA0 // write block
2868                                                 || receivedCmd[0] == 0xC0 // inc
2869                                                 || receivedCmd[0] == 0xC1 // dec
2870                                                 || receivedCmd[0] == 0xC2 // restore
2871                                                 || receivedCmd[0] == 0xB0) { // transfer
2872                                         if (receivedCmd[1] >= 16 * 4) {
2873                                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2874                                                 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]);
2875                                                 break;
2876                                         }
2877
2878                                         if (receivedCmd[1] / 4 != cardAUTHSC) {
2879                                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2880                                                 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);
2881                                                 break;
2882                                         }
2883                                 }
2884                                 // read block
2885                                 if (receivedCmd[0] == 0x30) {
2886                                         if (MF_DBGLEVEL >= 4) Dbprintf("Reader reading block %d (0x%02x)",receivedCmd[1],receivedCmd[1]);
2887
2888                                         emlGetMem(response, receivedCmd[1], 1);
2889                                         AppendCrc14443a(response, 16);
2890                                         mf_crypto1_encrypt(pcs, response, 18, response_par);
2891                                         EmSendCmdPar(response, 18, response_par);
2892                                         numReads++;
2893                                         if(exitAfterNReads > 0 && numReads >= exitAfterNReads) {
2894                                                 Dbprintf("%d reads done, exiting", numReads);
2895                                                 finished = true;
2896                                         }
2897                                         break;
2898                                 }
2899                                 // write block
2900                                 if (receivedCmd[0] == 0xA0) {
2901                                         if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0xA0 write block %d (%02x)",receivedCmd[1],receivedCmd[1]);
2902                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2903                                         cardSTATE = MFEMUL_WRITEBL2;
2904                                         cardWRBL = receivedCmd[1];
2905                                         break;
2906                                 }
2907                                 // increment, decrement, restore
2908                                 if (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2) {
2909                                         if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2910                                         if (emlCheckValBl(receivedCmd[1])) {
2911                                                 if (MF_DBGLEVEL >= 4) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking");
2912                                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2913                                                 break;
2914                                         }
2915                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2916                                         if (receivedCmd[0] == 0xC1)
2917                                                 cardSTATE = MFEMUL_INTREG_INC;
2918                                         if (receivedCmd[0] == 0xC0)
2919                                                 cardSTATE = MFEMUL_INTREG_DEC;
2920                                         if (receivedCmd[0] == 0xC2)
2921                                                 cardSTATE = MFEMUL_INTREG_REST;
2922                                         cardWRBL = receivedCmd[1];
2923                                         break;
2924                                 }
2925                                 // transfer
2926                                 if (receivedCmd[0] == 0xB0) {
2927                                         if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x transfer block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2928                                         if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
2929                                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2930                                         else
2931                                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2932                                         break;
2933                                 }
2934                                 // halt
2935                                 if (receivedCmd[0] == 0x50 && receivedCmd[1] == 0x00) {
2936                                         LED_B_OFF();
2937                                         LED_C_OFF();
2938                                         cardSTATE = MFEMUL_HALTED;
2939                                         if (MF_DBGLEVEL >= 4)   Dbprintf("--> HALTED. Selected time: %d ms",  GetTickCount() - selTimer);
2940                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2941                                         break;
2942                                 }
2943                                 // RATS
2944                                 if (receivedCmd[0] == 0xe0) {//RATS
2945                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2946                                         break;
2947                                 }
2948                                 // command not allowed
2949                                 if (MF_DBGLEVEL >= 4)   Dbprintf("Received command not allowed, nacking");
2950                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2951                                 break;
2952                         }
2953                         case MFEMUL_WRITEBL2:{
2954                                 if (len == 18) {
2955                                         mf_crypto1_decrypt(pcs, receivedCmd, len);
2956                                         emlSetMem(receivedCmd, cardWRBL, 1);
2957                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2958                                         cardSTATE = MFEMUL_WORK;
2959                                 } else {
2960                                         cardSTATE_TO_IDLE();
2961                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2962                                 }
2963                                 break;
2964                         }
2965
2966                         case MFEMUL_INTREG_INC:{
2967                                 mf_crypto1_decrypt(pcs, receivedCmd, len);
2968                                 memcpy(&ans, receivedCmd, 4);
2969                                 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2970                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2971                                         cardSTATE_TO_IDLE();
2972                                         break;
2973                                 }
2974                                 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2975                                 cardINTREG = cardINTREG + ans;
2976                                 cardSTATE = MFEMUL_WORK;
2977                                 break;
2978                         }
2979                         case MFEMUL_INTREG_DEC:{
2980                                 mf_crypto1_decrypt(pcs, receivedCmd, len);
2981                                 memcpy(&ans, receivedCmd, 4);
2982                                 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2983                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2984                                         cardSTATE_TO_IDLE();
2985                                         break;
2986                                 }
2987                                 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2988                                 cardINTREG = cardINTREG - ans;
2989                                 cardSTATE = MFEMUL_WORK;
2990                                 break;
2991                         }
2992                         case MFEMUL_INTREG_REST:{
2993                                 mf_crypto1_decrypt(pcs, receivedCmd, len);
2994                                 memcpy(&ans, receivedCmd, 4);
2995                                 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2996                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2997                                         cardSTATE_TO_IDLE();
2998                                         break;
2999                                 }
3000                                 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
3001                                 cardSTATE = MFEMUL_WORK;
3002                                 break;
3003                         }
3004                 }
3005         }
3006
3007         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
3008         LEDsoff();
3009
3010         // Interactive mode flag, means we need to send ACK
3011         if(flags & FLAG_INTERACTIVE) {
3012                 //May just aswell send the collected ar_nr in the response aswell
3013                 uint8_t len = ar_nr_collected*5*4;
3014                 cmd_send(CMD_ACK, CMD_SIMULATE_MIFARE_CARD, len, 0, &ar_nr_responses, len);
3015         }
3016
3017         if(flags & FLAG_NR_AR_ATTACK && MF_DBGLEVEL >= 1 ) {
3018                 if(ar_nr_collected > 1 ) {
3019                         Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
3020                         Dbprintf("../tools/mfkey/mfkey32 %06x%08x %08x %08x %08x %08x %08x",
3021                                         ar_nr_responses[0], // UID1
3022                                         ar_nr_responses[1], // UID2
3023                                         ar_nr_responses[2], // NT
3024                                         ar_nr_responses[3], // AR1
3025                                         ar_nr_responses[4], // NR1
3026                                         ar_nr_responses[8], // AR2
3027                                         ar_nr_responses[9]  // NR2
3028                                         );
3029                         Dbprintf("../tools/mfkey/mfkey32v2 %06x%08x %08x %08x %08x %08x %08x %08x",
3030                                         ar_nr_responses[0], // UID1
3031                                         ar_nr_responses[1], // UID2
3032                                         ar_nr_responses[2], // NT1
3033                                         ar_nr_responses[3], // AR1
3034                                         ar_nr_responses[4], // NR1
3035                                         ar_nr_responses[7], // NT2
3036                                         ar_nr_responses[8], // AR2
3037                                         ar_nr_responses[9]  // NR2
3038                                         );
3039                 } else {
3040                         Dbprintf("Failed to obtain two AR/NR pairs!");
3041                         if(ar_nr_collected > 0 ) {
3042                                 Dbprintf("Only got these: UID=%06x%08x, nonce=%08x, AR1=%08x, NR1=%08x",
3043                                                 ar_nr_responses[0], // UID1
3044                                                 ar_nr_responses[1], // UID2
3045                                                 ar_nr_responses[2], // NT
3046                                                 ar_nr_responses[3], // AR1
3047                                                 ar_nr_responses[4]  // NR1
3048                                                 );
3049                         }
3050                 }
3051         }
3052         if (MF_DBGLEVEL >= 1)   Dbprintf("Emulator stopped. Tracing: %d  trace length: %d ", tracing, BigBuf_get_traceLen());
3053
3054         set_tracing(FALSE);
3055 }
3056
3057
3058 //-----------------------------------------------------------------------------
3059 // MIFARE sniffer.
3060 //
3061 //-----------------------------------------------------------------------------
3062 void RAMFUNC SniffMifare(uint8_t param) {
3063         // param:
3064         // bit 0 - trigger from first card answer
3065         // bit 1 - trigger from first reader 7-bit request
3066         LEDsoff();
3067
3068         // free eventually allocated BigBuf memory
3069         BigBuf_free(); BigBuf_Clear_ext(false);
3070
3071         // init trace buffer
3072         clear_trace();
3073         set_tracing(TRUE);
3074
3075         // The command (reader -> tag) that we're receiving.
3076         // The length of a received command will in most cases be no more than 18 bytes.
3077         // So 32 should be enough!
3078         uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE] = {0x00};
3079         uint8_t receivedCmdPar[MAX_MIFARE_PARITY_SIZE] = {0x00};
3080
3081         // The response (tag -> reader) that we're receiving.
3082         uint8_t receivedResponse[MAX_MIFARE_FRAME_SIZE] = {0x00};
3083         uint8_t receivedResponsePar[MAX_MIFARE_PARITY_SIZE] = {0x00};
3084
3085         iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
3086
3087         // allocate the DMA buffer, used to stream samples from the FPGA
3088         uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
3089         uint8_t *data = dmaBuf;
3090         uint8_t previous_data = 0;
3091         int maxDataLen = 0;
3092         int dataLen = 0;
3093         bool ReaderIsActive = FALSE;
3094         bool TagIsActive = FALSE;
3095
3096         // Set up the demodulator for tag -> reader responses.
3097         DemodInit(receivedResponse, receivedResponsePar);
3098
3099         // Set up the demodulator for the reader -> tag commands
3100         UartInit(receivedCmd, receivedCmdPar);
3101
3102         // Setup for the DMA.
3103         FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
3104
3105         LED_D_OFF();
3106
3107         // init sniffer
3108         MfSniffInit();
3109
3110         // And now we loop, receiving samples.
3111         for(uint32_t sniffCounter = 0; TRUE; ) {
3112
3113                 if(BUTTON_PRESS()) {
3114                         DbpString("cancelled by button");
3115                         break;
3116                 }
3117
3118                 LED_A_ON();
3119                 WDT_HIT();
3120
3121                 if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time
3122                         // check if a transaction is completed (timeout after 2000ms).
3123                         // if yes, stop the DMA transfer and send what we have so far to the client
3124                         if (MfSniffSend(2000)) {
3125                                 // Reset everything - we missed some sniffed data anyway while the DMA was stopped
3126                                 sniffCounter = 0;
3127                                 data = dmaBuf;
3128                                 maxDataLen = 0;
3129                                 ReaderIsActive = FALSE;
3130                                 TagIsActive = FALSE;
3131                                 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
3132                         }
3133                 }
3134
3135                 int register readBufDataP = data - dmaBuf;      // number of bytes we have processed so far
3136                 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred
3137
3138                 if (readBufDataP <= dmaBufDataP)                        // we are processing the same block of data which is currently being transferred
3139                         dataLen = dmaBufDataP - readBufDataP;   // number of bytes still to be processed
3140                 else
3141                         dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed
3142
3143                 // test for length of buffer
3144                 if(dataLen > maxDataLen) {                                      // we are more behind than ever...
3145                         maxDataLen = dataLen;
3146                         if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
3147                                 Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
3148                                 break;
3149                         }
3150                 }
3151                 if(dataLen < 1) continue;
3152
3153                 // primary buffer was stopped ( <-- we lost data!
3154                 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
3155                         AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
3156                         AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
3157                         Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
3158                 }
3159                 // secondary buffer sets as primary, secondary buffer was stopped
3160                 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
3161                         AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
3162                         AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
3163                 }
3164
3165                 LED_A_OFF();
3166
3167                 if (sniffCounter & 0x01) {
3168
3169                         // no need to try decoding tag data if the reader is sending
3170                         if(!TagIsActive) {
3171                                 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
3172                                 if(MillerDecoding(readerdata, (sniffCounter-1)*4)) {
3173                                         LED_C_INV();
3174
3175                                         if (MfSniffLogic(receivedCmd, Uart.len, Uart.parity, Uart.bitCount, TRUE)) break;
3176
3177                                         /* And ready to receive another command. */
3178                                         UartInit(receivedCmd, receivedCmdPar);
3179
3180                                         /* And also reset the demod code */
3181                                         DemodReset();
3182                                 }
3183                                 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
3184                         }
3185
3186                         // no need to try decoding tag data if the reader is sending
3187                         if(!ReaderIsActive) {
3188                                 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
3189                                 if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) {
3190                                         LED_C_INV();
3191
3192                                         if (MfSniffLogic(receivedResponse, Demod.len, Demod.parity, Demod.bitCount, FALSE)) break;
3193
3194                                         // And ready to receive another response.
3195                                         DemodReset();
3196
3197                                         // And reset the Miller decoder including its (now outdated) input buffer
3198                                         UartInit(receivedCmd, receivedCmdPar);
3199                                 }
3200                                 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
3201                         }
3202                 }
3203
3204                 previous_data = *data;
3205                 sniffCounter++;
3206                 data++;
3207
3208                 if(data == dmaBuf + DMA_BUFFER_SIZE)
3209                         data = dmaBuf;
3210
3211         } // main cycle
3212
3213         FpgaDisableSscDma();
3214         MfSniffEnd();
3215         LEDsoff();
3216         Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len);
3217         set_tracing(FALSE);
3218 }