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 "crapto1.h"
  21 #include "mifareutil.h"
  22 #include "BigBuf.h"
  23 #include "parity.h"
  24
  25 static uint32_t iso14a_timeout;
  26 int rsamples = 0;
  27 uint8_t trigger = 0;
  28 // the block number for the ISO14443-4 PCB
  29 static uint8_t iso14_pcb_blocknum = 0;
  30
  31 //
  32 // ISO14443 timing:
  33 //
  34 // minimum time between the start bits of consecutive transfers from reader to tag: 7000 carrier (13.56Mhz) cycles
  35 #define REQUEST_GUARD_TIME (7000/16 + 1)
  36 // minimum time between last modulation of tag and next start bit from reader to tag: 1172 carrier cycles
  37 #define FRAME_DELAY_TIME_PICC_TO_PCD (1172/16 + 1)
  38 // bool LastCommandWasRequest = FALSE;
  39
  40 //
  41 // Total delays including SSC-Transfers between ARM and FPGA. These are in carrier clock cycles (1/13,56MHz)
  42 //
  43 // When the PM acts as reader and is receiving tag data, it takes
  44 // 3 ticks delay in the AD converter
  45 // 16 ticks until the modulation detector completes and sets curbit
  46 // 8 ticks until bit_to_arm is assigned from curbit
  47 // 8*16 ticks for the transfer from FPGA to ARM
  48 // 4*16 ticks until we measure the time
  49 // - 8*16 ticks because we measure the time of the previous transfer
  50 #define DELAY_AIR2ARM_AS_READER (3 + 16 + 8 + 8*16 + 4*16 - 8*16)
  51
  52 // When the PM acts as a reader and is sending, it takes
  53 // 4*16 ticks until we can write data to the sending hold register
  54 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
  55 // 8 ticks until the first transfer starts
  56 // 8 ticks later the FPGA samples the data
  57 // 1 tick to assign mod_sig_coil
  58 #define DELAY_ARM2AIR_AS_READER (4*16 + 8*16 + 8 + 8 + 1)
  59
  60 // When the PM acts as tag and is receiving it takes
  61 // 2 ticks delay in the RF part (for the first falling edge),
  62 // 3 ticks for the A/D conversion,
  63 // 8 ticks on average until the start of the SSC transfer,
  64 // 8 ticks until the SSC samples the first data
  65 // 7*16 ticks to complete the transfer from FPGA to ARM
  66 // 8 ticks until the next ssp_clk rising edge
  67 // 4*16 ticks until we measure the time
  68 // - 8*16 ticks because we measure the time of the previous transfer
  69 #define DELAY_AIR2ARM_AS_TAG (2 + 3 + 8 + 8 + 7*16 + 8 + 4*16 - 8*16)
  70
  71 // The FPGA will report its internal sending delay in
  72 uint16_t FpgaSendQueueDelay;
  73 // the 5 first bits are the number of bits buffered in mod_sig_buf
  74 // the last three bits are the remaining ticks/2 after the mod_sig_buf shift
  75 #define DELAY_FPGA_QUEUE (FpgaSendQueueDelay<<1)
  76
  77 // When the PM acts as tag and is sending, it takes
  78 // 4*16 ticks until we can write data to the sending hold register
  79 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
  80 // 8 ticks until the first transfer starts
  81 // 8 ticks later the FPGA samples the data
  82 // + a varying number of ticks in the FPGA Delay Queue (mod_sig_buf)
  83 // + 1 tick to assign mod_sig_coil
  84 #define DELAY_ARM2AIR_AS_TAG (4*16 + 8*16 + 8 + 8 + DELAY_FPGA_QUEUE + 1)
  85
  86 // When the PM acts as sniffer and is receiving tag data, it takes
  87 // 3 ticks A/D conversion
  88 // 14 ticks to complete the modulation detection
  89 // 8 ticks (on average) until the result is stored in to_arm
  90 // + the delays in transferring data - which is the same for
  91 // sniffing reader and tag data and therefore not relevant
  92 #define DELAY_TAG_AIR2ARM_AS_SNIFFER (3 + 14 + 8)
  93
  94 // When the PM acts as sniffer and is receiving reader data, it takes
  95 // 2 ticks delay in analogue RF receiver (for the falling edge of the
  96 // start bit, which marks the start of the communication)
  97 // 3 ticks A/D conversion
  98 // 8 ticks on average until the data is stored in to_arm.
  99 // + the delays in transferring data - which is the same for
 100 // sniffing reader and tag data and therefore not relevant
 101 #define DELAY_READER_AIR2ARM_AS_SNIFFER (2 + 3 + 8)
 102
 103 //variables used for timing purposes:
 104 //these are in ssp_clk cycles:
 105 static uint32_t NextTransferTime;
 106 static uint32_t LastTimeProxToAirStart;
 107 static uint32_t LastProxToAirDuration;
 108
 109 // CARD TO READER - manchester
 110 // Sequence D: 11110000 modulation with subcarrier during first half
 111 // Sequence E: 00001111 modulation with subcarrier during second half
 112 // Sequence F: 00000000 no modulation with subcarrier
 113 // READER TO CARD - miller
 114 // Sequence X: 00001100 drop after half a period
 115 // Sequence Y: 00000000 no drop
 116 // Sequence Z: 11000000 drop at start
 117 #define SEC_D 0xf0
 118 #define SEC_E 0x0f
 119 #define SEC_F 0x00
 120 #define SEC_X 0x0c
 121 #define SEC_Y 0x00
 122 #define SEC_Z 0xc0
 123
 124 void iso14a_set_trigger(bool enable) {
 125         trigger = enable;
 126 }
 127
 128 void iso14a_set_timeout(uint32_t timeout) {
 129         iso14a_timeout = timeout;
 130         if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443A Timeout set to %ld (%dms)", iso14a_timeout, iso14a_timeout / 106);
 131 }
 132
 133 void iso14a_set_ATS_timeout(uint8_t *ats) {
 134
 135         uint8_t tb1;
 136         uint8_t fwi;
 137         uint32_t fwt;
 138
 139         if (ats[0] > 1) {                                                       // there is a format byte T0
 140                 if ((ats[1] & 0x20) == 0x20) {                  // there is an interface byte TB(1)
 141
 142                         if ((ats[1] & 0x10) == 0x10)            // there is an interface byte TA(1) preceding TB(1)
 143                                 tb1 = ats[3];
 144                         else
 145                                 tb1 = ats[2];
 146
 147                         fwi = (tb1 & 0xf0) >> 4;                        // frame waiting indicator (FWI)
 148                         //fwt = 256 * 16 * (1 << fwi);          // frame waiting time (FWT) in 1/fc
 149                         fwt = 4096 * (1 << fwi);
 150
 151                         //iso14a_set_timeout(fwt/(8*16));
 152                         iso14a_set_timeout(fwt/128);
 153                 }
 154         }
 155 }
 156
 157 //-----------------------------------------------------------------------------
 158 // Generate the parity value for a byte sequence
 159 //
 160 //-----------------------------------------------------------------------------
 161 void GetParity(const uint8_t *pbtCmd, uint16_t iLen, uint8_t *par)
 162 {
 163         uint16_t paritybit_cnt = 0;
 164         uint16_t paritybyte_cnt = 0;
 165         uint8_t parityBits = 0;
 166
 167         for (uint16_t i = 0; i < iLen; i++) {
 168                 // Generate the parity bits
 169                 parityBits |= ((oddparity8(pbtCmd[i])) << (7-paritybit_cnt));
 170                 if (paritybit_cnt == 7) {
 171                         par[paritybyte_cnt] = parityBits;       // save 8 Bits parity
 172                         parityBits = 0;                                         // and advance to next Parity Byte
 173                         paritybyte_cnt++;
 174                         paritybit_cnt = 0;
 175                 } else {
 176                         paritybit_cnt++;
 177                 }
 178         }
 179
 180         // save remaining parity bits
 181         par[paritybyte_cnt] = parityBits;
 182
 183 }
 184
 185 void AppendCrc14443a(uint8_t* data, int len)
 186 {
 187         ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1);
 188 }
 189
 190 void AppendCrc14443b(uint8_t* data, int len)
 191 {
 192         ComputeCrc14443(CRC_14443_B,data,len,data+len,data+len+1);
 193 }
 194
 195
 196 //=============================================================================
 197 // ISO 14443 Type A - Miller decoder
 198 //=============================================================================
 199 // Basics:
 200 // This decoder is used when the PM3 acts as a tag.
 201 // The reader will generate "pauses" by temporarily switching of the field.
 202 // At the PM3 antenna we will therefore measure a modulated antenna voltage.
 203 // The FPGA does a comparison with a threshold and would deliver e.g.:
 204 // ........  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  .......
 205 // The Miller decoder needs to identify the following sequences:
 206 // 2 (or 3) ticks pause followed by 6 (or 5) ticks unmodulated:         pause at beginning - Sequence Z ("start of communication" or a "0")
 207 // 8 ticks without a modulation:                                                                        no pause - Sequence Y (a "0" or "end of communication" or "no information")
 208 // 4 ticks unmodulated followed by 2 (or 3) ticks pause:                        pause in second half - Sequence X (a "1")
 209 // Note 1: the bitstream may start at any time. We therefore need to sync.
 210 // Note 2: the interpretation of Sequence Y and Z depends on the preceding sequence.
 211 //-----------------------------------------------------------------------------
 212 static tUart Uart;
 213
 214 // Lookup-Table to decide if 4 raw bits are a modulation.
 215 // We accept the following:
 216 // 0001  -   a 3 tick wide pause
 217 // 0011  -   a 2 tick wide pause, or a three tick wide pause shifted left
 218 // 0111  -   a 2 tick wide pause shifted left
 219 // 1001  -   a 2 tick wide pause shifted right
 220 const bool Mod_Miller_LUT[] = {
 221         FALSE,  TRUE, FALSE, TRUE,  FALSE, FALSE, FALSE, TRUE,
 222         FALSE,  TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE
 223 };
 224 #define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x000000F0) >> 4])
 225 #define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x0000000F)])
 226
 227 void UartReset()
 228 {
 229         Uart.state = STATE_UNSYNCD;
 230         Uart.bitCount = 0;
 231         Uart.len = 0;                                           // number of decoded data bytes
 232         Uart.parityLen = 0;                                     // number of decoded parity bytes
 233         Uart.shiftReg = 0;                                      // shiftreg to hold decoded data bits
 234         Uart.parityBits = 0;                            // holds 8 parity bits
 235         Uart.startTime = 0;
 236         Uart.endTime = 0;
 237
 238         Uart.byteCntMax = 0;
 239         Uart.posCnt = 0;
 240         Uart.syncBit = 9999;
 241 }
 242
 243 void UartInit(uint8_t *data, uint8_t *parity)
 244 {
 245         Uart.output = data;
 246         Uart.parity = parity;
 247         Uart.fourBits = 0x00000000;                     // clear the buffer for 4 Bits
 248         UartReset();
 249 }
 250
 251 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
 252 static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
 253 {
 254
 255         Uart.fourBits = (Uart.fourBits << 8) | bit;
 256
 257         if (Uart.state == STATE_UNSYNCD) {                                                                                      // not yet synced
 258
 259                 Uart.syncBit = 9999;                                                                                                    // not set
 260
 261                 // 00x11111 2|3 ticks pause followed by 6|5 ticks unmodulated           Sequence Z (a "0" or "start of communication")
 262                 // 11111111 8 ticks unmodulation                                                                        Sequence Y (a "0" or "end of communication" or "no information")
 263                 // 111100x1 4 ticks unmodulated followed by 2|3 ticks pause                     Sequence X (a "1")
 264
 265                 // The start bit is one ore more Sequence Y followed by a Sequence Z (... 11111111 00x11111). We need to distinguish from
 266                 // Sequence X followed by Sequence Y followed by Sequence Z     (111100x1 11111111 00x11111)
 267                 // we therefore look for a ...xx1111 11111111 00x11111xxxxxx... pattern
 268                 // (12 '1's followed by 2 '0's, eventually followed by another '0', followed by 5 '1's)
 269                 //
 270 #define ISO14443A_STARTBIT_MASK         0x07FFEF80              // mask is    00001111 11111111 1110 1111 10000000
 271 #define ISO14443A_STARTBIT_PATTERN      0x07FF8F80              // pattern is 00001111 11111111 1000 1111 10000000
 272
 273                 if              ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 0)) == ISO14443A_STARTBIT_PATTERN >> 0) Uart.syncBit = 7;
 274                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 1)) == ISO14443A_STARTBIT_PATTERN >> 1) Uart.syncBit = 6;
 275                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 2)) == ISO14443A_STARTBIT_PATTERN >> 2) Uart.syncBit = 5;
 276                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 3)) == ISO14443A_STARTBIT_PATTERN >> 3) Uart.syncBit = 4;
 277                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 4)) == ISO14443A_STARTBIT_PATTERN >> 4) Uart.syncBit = 3;
 278                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 5)) == ISO14443A_STARTBIT_PATTERN >> 5) Uart.syncBit = 2;
 279                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 6)) == ISO14443A_STARTBIT_PATTERN >> 6) Uart.syncBit = 1;
 280                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 7)) == ISO14443A_STARTBIT_PATTERN >> 7) Uart.syncBit = 0;
 281
 282                 if (Uart.syncBit != 9999) {                                                                                             // found a sync bit
 283                                 Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
 284                                 Uart.startTime -= Uart.syncBit;
 285                                 Uart.endTime = Uart.startTime;
 286                                 Uart.state = STATE_START_OF_COMMUNICATION;
 287                         }
 288
 289         } else {
 290
 291                 if (IsMillerModulationNibble1(Uart.fourBits >> Uart.syncBit)) {
 292                         if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) {         // Modulation in both halves - error
 293                                 UartReset();
 294                         } else {                                                                                                                        // Modulation in first half = Sequence Z = logic "0"
 295                                 if (Uart.state == STATE_MILLER_X) {                                                             // error - must not follow after X
 296                                         UartReset();
 297                                 } else {
 298                                         Uart.bitCount++;
 299                                         Uart.shiftReg = (Uart.shiftReg >> 1);                                           // add a 0 to the shiftreg
 300                                         Uart.state = STATE_MILLER_Z;
 301                                         Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 6;
 302                                         if(Uart.bitCount >= 9) {                                                                        // if we decoded a full byte (including parity)
 303                                                 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
 304                                                 Uart.parityBits <<= 1;                                                                  // make room for the parity bit
 305                                                 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01);               // store parity bit
 306                                                 Uart.bitCount = 0;
 307                                                 Uart.shiftReg = 0;
 308                                                 if((Uart.len&0x0007) == 0) {                                                    // every 8 data bytes
 309                                                         Uart.parity[Uart.parityLen++] = Uart.parityBits;        // store 8 parity bits
 310                                                         Uart.parityBits = 0;
 311                                                 }
 312                                         }
 313                                 }
 314                         }
 315                 } else {
 316                         if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) {         // Modulation second half = Sequence X = logic "1"
 317                                 Uart.bitCount++;
 318                                 Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100;                                   // add a 1 to the shiftreg
 319                                 Uart.state = STATE_MILLER_X;
 320                                 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 2;
 321                                 if(Uart.bitCount >= 9) {                                                                                // if we decoded a full byte (including parity)
 322                                         Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
 323                                         Uart.parityBits <<= 1;                                                                          // make room for the new parity bit
 324                                         Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01);                       // store parity bit
 325                                         Uart.bitCount = 0;
 326                                         Uart.shiftReg = 0;
 327                                         if ((Uart.len&0x0007) == 0) {                                                           // every 8 data bytes
 328                                                 Uart.parity[Uart.parityLen++] = Uart.parityBits;                // store 8 parity bits
 329                                                 Uart.parityBits = 0;
 330                                         }
 331                                 }
 332                         } else {                                                                                                                        // no modulation in both halves - Sequence Y
 333                                 if (Uart.state == STATE_MILLER_Z || Uart.state == STATE_MILLER_Y) {     // Y after logic "0" - End of Communication
 334                                         Uart.state = STATE_UNSYNCD;
 335                                         Uart.bitCount--;                                                                                        // last "0" was part of EOC sequence
 336                                         Uart.shiftReg <<= 1;                                                                            // drop it
 337                                         if(Uart.bitCount > 0) {                                                                         // if we decoded some bits
 338                                                 Uart.shiftReg >>= (9 - Uart.bitCount);                                  // right align them
 339                                                 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);               // add last byte to the output
 340                                                 Uart.parityBits <<= 1;                                                                  // add a (void) parity bit
 341                                                 Uart.parityBits <<= (8 - (Uart.len&0x0007));                    // left align parity bits
 342                                                 Uart.parity[Uart.parityLen++] = Uart.parityBits;                // and store it
 343                                                 return TRUE;
 344                                         } else if (Uart.len & 0x0007) {                                                         // there are some parity bits to store
 345                                                 Uart.parityBits <<= (8 - (Uart.len&0x0007));                    // left align remaining parity bits
 346                                                 Uart.parity[Uart.parityLen++] = Uart.parityBits;                // and store them
 347                                         }
 348                                         if (Uart.len) {
 349                                                 return TRUE;                                                                                    // we are finished with decoding the raw data sequence
 350                                         } else {
 351                                                 UartReset();                                                                                    // Nothing received - start over
 352                                         }
 353                                 }
 354                                 if (Uart.state == STATE_START_OF_COMMUNICATION) {                               // error - must not follow directly after SOC
 355                                         UartReset();
 356                                 } else {                                                                                                                // a logic "0"
 357                                         Uart.bitCount++;
 358                                         Uart.shiftReg = (Uart.shiftReg >> 1);                                           // add a 0 to the shiftreg
 359                                         Uart.state = STATE_MILLER_Y;
 360                                         if(Uart.bitCount >= 9) {                                                                        // if we decoded a full byte (including parity)
 361                                                 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
 362                                                 Uart.parityBits <<= 1;                                                                  // make room for the parity bit
 363                                                 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01);               // store parity bit
 364                                                 Uart.bitCount = 0;
 365                                                 Uart.shiftReg = 0;
 366                                                 if ((Uart.len&0x0007) == 0) {                                                   // every 8 data bytes
 367                                                         Uart.parity[Uart.parityLen++] = Uart.parityBits;        // store 8 parity bits
 368                                                         Uart.parityBits = 0;
 369                                                 }
 370                                         }
 371                                 }
 372                         }
 373                 }
 374
 375         }
 376
 377     return FALSE;       // not finished yet, need more data
 378 }
 379
 380
 381
 382 //=============================================================================
 383 // ISO 14443 Type A - Manchester decoder
 384 //=============================================================================
 385 // Basics:
 386 // This decoder is used when the PM3 acts as a reader.
 387 // The tag will modulate the reader field by asserting different loads to it. As a consequence, the voltage
 388 // at the reader antenna will be modulated as well. The FPGA detects the modulation for us and would deliver e.g. the following:
 389 // ........ 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 .......
 390 // The Manchester decoder needs to identify the following sequences:
 391 // 4 ticks modulated followed by 4 ticks unmodulated:   Sequence D = 1 (also used as "start of communication")
 392 // 4 ticks unmodulated followed by 4 ticks modulated:   Sequence E = 0
 393 // 8 ticks unmodulated:                                                                 Sequence F = end of communication
 394 // 8 ticks modulated:                                                                   A collision. Save the collision position and treat as Sequence D
 395 // Note 1: the bitstream may start at any time. We therefore need to sync.
 396 // Note 2: parameter offset is used to determine the position of the parity bits (required for the anticollision command only)
 397 static tDemod Demod;
 398
 399 // Lookup-Table to decide if 4 raw bits are a modulation.
 400 // We accept three or four "1" in any position
 401 const bool Mod_Manchester_LUT[] = {
 402         FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE,
 403         FALSE, FALSE, FALSE, TRUE,  FALSE, TRUE,  TRUE,  TRUE
 404 };
 405
 406 #define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4])
 407 #define IsManchesterModulationNibble2(b) (Mod_Manchester_LUT[(b & 0x000F)])
 408
 409
 410 void DemodReset()
 411 {
 412         Demod.state = DEMOD_UNSYNCD;
 413         Demod.len = 0;                                          // number of decoded data bytes
 414         Demod.parityLen = 0;
 415         Demod.shiftReg = 0;                                     // shiftreg to hold decoded data bits
 416         Demod.parityBits = 0;                           //
 417         Demod.collisionPos = 0;                         // Position of collision bit
 418         Demod.twoBits = 0xffff;                         // buffer for 2 Bits
 419         Demod.highCnt = 0;
 420         Demod.startTime = 0;
 421         Demod.endTime = 0;
 422
 423         //
 424         Demod.bitCount = 0;
 425         Demod.syncBit = 0xFFFF;
 426         Demod.samples = 0;
 427 }
 428
 429 void DemodInit(uint8_t *data, uint8_t *parity)
 430 {
 431         Demod.output = data;
 432         Demod.parity = parity;
 433         DemodReset();
 434 }
 435
 436 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
 437 static RAMFUNC int ManchesterDecoding(uint8_t bit, uint16_t offset, uint32_t non_real_time)
 438 {
 439
 440         Demod.twoBits = (Demod.twoBits << 8) | bit;
 441
 442         if (Demod.state == DEMOD_UNSYNCD) {
 443
 444                 if (Demod.highCnt < 2) {                                                                                        // wait for a stable unmodulated signal
 445                         if (Demod.twoBits == 0x0000) {
 446                                 Demod.highCnt++;
 447                         } else {
 448                                 Demod.highCnt = 0;
 449                         }
 450                 } else {
 451                         Demod.syncBit = 0xFFFF;                 // not set
 452                         if              ((Demod.twoBits & 0x7700) == 0x7000) Demod.syncBit = 7;
 453                         else if ((Demod.twoBits & 0x3B80) == 0x3800) Demod.syncBit = 6;
 454                         else if ((Demod.twoBits & 0x1DC0) == 0x1C00) Demod.syncBit = 5;
 455                         else if ((Demod.twoBits & 0x0EE0) == 0x0E00) Demod.syncBit = 4;
 456                         else if ((Demod.twoBits & 0x0770) == 0x0700) Demod.syncBit = 3;
 457                         else if ((Demod.twoBits & 0x03B8) == 0x0380) Demod.syncBit = 2;
 458                         else if ((Demod.twoBits & 0x01DC) == 0x01C0) Demod.syncBit = 1;
 459                         else if ((Demod.twoBits & 0x00EE) == 0x00E0) Demod.syncBit = 0;
 460                         if (Demod.syncBit != 0xFFFF) {
 461                                 Demod.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
 462                                 Demod.startTime -= Demod.syncBit;
 463                                 Demod.bitCount = offset;                        // number of decoded data bits
 464                                 Demod.state = DEMOD_MANCHESTER_DATA;
 465                         }
 466                 }
 467
 468         } else {
 469
 470                 if (IsManchesterModulationNibble1(Demod.twoBits >> Demod.syncBit)) {            // modulation in first half
 471                         if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) {    // ... and in second half = collision
 472                                 if (!Demod.collisionPos) {
 473                                         Demod.collisionPos = (Demod.len << 3) + Demod.bitCount;
 474                                 }
 475                         }                                                                                                                       // modulation in first half only - Sequence D = 1
 476                         Demod.bitCount++;
 477                         Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100;                         // in both cases, add a 1 to the shiftreg
 478                         if(Demod.bitCount == 9) {                                                                       // if we decoded a full byte (including parity)
 479                                 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
 480                                 Demod.parityBits <<= 1;                                                                 // make room for the parity bit
 481                                 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01);     // store parity bit
 482                                 Demod.bitCount = 0;
 483                                 Demod.shiftReg = 0;
 484                                 if((Demod.len&0x0007) == 0) {                                                   // every 8 data bytes
 485                                         Demod.parity[Demod.parityLen++] = Demod.parityBits;     // store 8 parity bits
 486                                         Demod.parityBits = 0;
 487                                 }
 488                         }
 489                         Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1) - 4;
 490                 } else {                                                                                                                // no modulation in first half
 491                         if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) {    // and modulation in second half = Sequence E = 0
 492                                 Demod.bitCount++;
 493                                 Demod.shiftReg = (Demod.shiftReg >> 1);                                 // add a 0 to the shiftreg
 494                                 if(Demod.bitCount >= 9) {                                                               // if we decoded a full byte (including parity)
 495                                         Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
 496                                         Demod.parityBits <<= 1;                                                         // make room for the new parity bit
 497                                         Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
 498                                         Demod.bitCount = 0;
 499                                         Demod.shiftReg = 0;
 500                                         if ((Demod.len&0x0007) == 0) {                                          // every 8 data bytes
 501                                                 Demod.parity[Demod.parityLen++] = Demod.parityBits;     // store 8 parity bits1
 502                                                 Demod.parityBits = 0;
 503                                         }
 504                                 }
 505                                 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1);
 506                         } else {                                                                                                        // no modulation in both halves - End of communication
 507                                 if(Demod.bitCount > 0) {                                                                // there are some remaining data bits
 508                                         Demod.shiftReg >>= (9 - Demod.bitCount);                        // right align the decoded bits
 509                                         Demod.output[Demod.len++] = Demod.shiftReg & 0xff;      // and add them to the output
 510                                         Demod.parityBits <<= 1;                                                         // add a (void) parity bit
 511                                         Demod.parityBits <<= (8 - (Demod.len&0x0007));          // left align remaining parity bits
 512                                         Demod.parity[Demod.parityLen++] = Demod.parityBits;     // and store them
 513                                         return TRUE;
 514                                 } else if (Demod.len & 0x0007) {                                                // there are some parity bits to store
 515                                         Demod.parityBits <<= (8 - (Demod.len&0x0007));          // left align remaining parity bits
 516                                         Demod.parity[Demod.parityLen++] = Demod.parityBits;     // and store them
 517                                 }
 518                                 if (Demod.len) {
 519                                         return TRUE;                                                                            // we are finished with decoding the raw data sequence
 520                                 } else {                                                                                                // nothing received. Start over
 521                                         DemodReset();
 522                                 }
 523                         }
 524                 }
 525         }
 526     return FALSE;       // not finished yet, need more data
 527 }
 528
 529 //=============================================================================
 530 // Finally, a `sniffer' for ISO 14443 Type A
 531 // Both sides of communication!
 532 //=============================================================================
 533
 534 //-----------------------------------------------------------------------------
 535 // Record the sequence of commands sent by the reader to the tag, with
 536 // triggering so that we start recording at the point that the tag is moved
 537 // near the reader.
 538 //-----------------------------------------------------------------------------
 539 void RAMFUNC SniffIso14443a(uint8_t param) {
 540         // param:
 541         // bit 0 - trigger from first card answer
 542         // bit 1 - trigger from first reader 7-bit request
 543         LEDsoff();
 544
 545         iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
 546
 547         // Allocate memory from BigBuf for some buffers
 548         // free all previous allocations first
 549         BigBuf_free();
 550
 551         // init trace buffer
 552         clear_trace();
 553         set_tracing(TRUE);
 554
 555         // The command (reader -> tag) that we're receiving.
 556         uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
 557         uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
 558
 559         // The response (tag -> reader) that we're receiving.
 560         uint8_t *receivedResponse = BigBuf_malloc(MAX_FRAME_SIZE);
 561         uint8_t *receivedResponsePar = BigBuf_malloc(MAX_PARITY_SIZE);
 562
 563         // The DMA buffer, used to stream samples from the FPGA
 564         uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
 565
 566         uint8_t *data = dmaBuf;
 567         uint8_t previous_data = 0;
 568         int maxDataLen = 0;
 569         int dataLen = 0;
 570         bool TagIsActive = FALSE;
 571         bool ReaderIsActive = FALSE;
 572
 573         // Set up the demodulator for tag -> reader responses.
 574         DemodInit(receivedResponse, receivedResponsePar);
 575
 576         // Set up the demodulator for the reader -> tag commands
 577         UartInit(receivedCmd, receivedCmdPar);
 578
 579         // Setup and start DMA.
 580         FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
 581
 582         // We won't start recording the frames that we acquire until we trigger;
 583         // a good trigger condition to get started is probably when we see a
 584         // response from the tag.
 585         // triggered == FALSE -- to wait first for card
 586         bool triggered = !(param & 0x03);
 587
 588         // And now we loop, receiving samples.
 589         for(uint32_t rsamples = 0; TRUE; ) {
 590
 591                 if(BUTTON_PRESS()) {
 592                         DbpString("cancelled by button");
 593                         break;
 594                 }
 595
 596                 LED_A_ON();
 597                 WDT_HIT();
 598
 599                 int register readBufDataP = data - dmaBuf;
 600                 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR;
 601                 if (readBufDataP <= dmaBufDataP){
 602                         dataLen = dmaBufDataP - readBufDataP;
 603                 } else {
 604                         dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP;
 605                 }
 606                 // test for length of buffer
 607                 if(dataLen > maxDataLen) {
 608                         maxDataLen = dataLen;
 609                         if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
 610                                 Dbprintf("blew circular buffer! dataLen=%d", dataLen);
 611                                 break;
 612                         }
 613                 }
 614                 if(dataLen < 1) continue;
 615
 616                 // primary buffer was stopped( <-- we lost data!
 617                 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
 618                         AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
 619                         AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
 620                         Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
 621                 }
 622                 // secondary buffer sets as primary, secondary buffer was stopped
 623                 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
 624                         AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
 625                         AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
 626                 }
 627
 628                 LED_A_OFF();
 629
 630                 if (rsamples & 0x01) {                          // Need two samples to feed Miller and Manchester-Decoder
 631
 632                         if(!TagIsActive) {              // no need to try decoding reader data if the tag is sending
 633                                 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
 634                                 if (MillerDecoding(readerdata, (rsamples-1)*4)) {
 635                                         LED_C_ON();
 636
 637                                         // check - if there is a short 7bit request from reader
 638                                         if ((!triggered) && (param & 0x02) && (Uart.len == 1) && (Uart.bitCount == 7)) triggered = TRUE;
 639
 640                                         if(triggered) {
 641                                                 if (!LogTrace(receivedCmd,
 642                                                                                 Uart.len,
 643                                                                                 Uart.startTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
 644                                                                                 Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
 645                                                                                 Uart.parity,
 646                                                                                 TRUE)) break;
 647                                         }
 648                                         /* And ready to receive another command. */
 649                                         UartReset();
 650                                         /* And also reset the demod code, which might have been */
 651                                         /* false-triggered by the commands from the reader. */
 652                                         DemodReset();
 653                                         LED_B_OFF();
 654                                 }
 655                                 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
 656                         }
 657
 658                         if(!ReaderIsActive) {           // no need to try decoding tag data if the reader is sending - and we cannot afford the time
 659                                 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
 660                                 if(ManchesterDecoding(tagdata, 0, (rsamples-1)*4)) {
 661                                         LED_B_ON();
 662
 663                                         if (!LogTrace(receivedResponse,
 664                                                                         Demod.len,
 665                                                                         Demod.startTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
 666                                                                         Demod.endTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
 667                                                                         Demod.parity,
 668                                                                         FALSE)) break;
 669
 670                                         if ((!triggered) && (param & 0x01)) triggered = TRUE;
 671
 672                                         // And ready to receive another response.
 673                                         DemodReset();
 674                                         // And reset the Miller decoder including itS (now outdated) input buffer
 675                                         UartInit(receivedCmd, receivedCmdPar);
 676
 677                                         LED_C_OFF();
 678                                 }
 679                                 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
 680                         }
 681                 }
 682
 683                 previous_data = *data;
 684                 rsamples++;
 685                 data++;
 686                 if(data == dmaBuf + DMA_BUFFER_SIZE) {
 687                         data = dmaBuf;
 688                 }
 689         } // main cycle
 690
 691         FpgaDisableSscDma();
 692         LEDsoff();
 693
 694         Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len);
 695         Dbprintf("traceLen=%d, Uart.output[0]=%08x", BigBuf_get_traceLen(), (uint32_t)Uart.output[0]);
 696
 697         set_tracing(FALSE);
 698 }
 699
 700 //-----------------------------------------------------------------------------
 701 // Prepare tag messages
 702 //-----------------------------------------------------------------------------
 703 static void CodeIso14443aAsTagPar(const uint8_t *cmd, uint16_t len, uint8_t *parity)
 704 {
 705         ToSendReset();
 706
 707         // Correction bit, might be removed when not needed
 708         ToSendStuffBit(0);
 709         ToSendStuffBit(0);
 710         ToSendStuffBit(0);
 711         ToSendStuffBit(0);
 712         ToSendStuffBit(1);  // 1
 713         ToSendStuffBit(0);
 714         ToSendStuffBit(0);
 715         ToSendStuffBit(0);
 716
 717         // Send startbit
 718         ToSend[++ToSendMax] = SEC_D;
 719         LastProxToAirDuration = 8 * ToSendMax - 4;
 720
 721         for(uint16_t i = 0; i < len; i++) {
 722                 uint8_t b = cmd[i];
 723
 724                 // Data bits
 725                 for(uint16_t j = 0; j < 8; j++) {
 726                         if(b & 1) {
 727                                 ToSend[++ToSendMax] = SEC_D;
 728                         } else {
 729                                 ToSend[++ToSendMax] = SEC_E;
 730                         }
 731                         b >>= 1;
 732                 }
 733
 734                 // Get the parity bit
 735                 if (parity[i>>3] & (0x80>>(i&0x0007))) {
 736                         ToSend[++ToSendMax] = SEC_D;
 737                         LastProxToAirDuration = 8 * ToSendMax - 4;
 738                 } else {
 739                         ToSend[++ToSendMax] = SEC_E;
 740                         LastProxToAirDuration = 8 * ToSendMax;
 741                 }
 742         }
 743
 744         // Send stopbit
 745         ToSend[++ToSendMax] = SEC_F;
 746
 747         // Convert from last byte pos to length
 748         ToSendMax++;
 749 }
 750
 751 static void CodeIso14443aAsTag(const uint8_t *cmd, uint16_t len)
 752 {
 753         uint8_t par[MAX_PARITY_SIZE];
 754
 755         GetParity(cmd, len, par);
 756         CodeIso14443aAsTagPar(cmd, len, par);
 757 }
 758
 759
 760 static void Code4bitAnswerAsTag(uint8_t cmd)
 761 {
 762         int i;
 763
 764         ToSendReset();
 765
 766         // Correction bit, might be removed when not needed
 767         ToSendStuffBit(0);
 768         ToSendStuffBit(0);
 769         ToSendStuffBit(0);
 770         ToSendStuffBit(0);
 771         ToSendStuffBit(1);  // 1
 772         ToSendStuffBit(0);
 773         ToSendStuffBit(0);
 774         ToSendStuffBit(0);
 775
 776         // Send startbit
 777         ToSend[++ToSendMax] = SEC_D;
 778
 779         uint8_t b = cmd;
 780         for(i = 0; i < 4; i++) {
 781                 if(b & 1) {
 782                         ToSend[++ToSendMax] = SEC_D;
 783                         LastProxToAirDuration = 8 * ToSendMax - 4;
 784                 } else {
 785                         ToSend[++ToSendMax] = SEC_E;
 786                         LastProxToAirDuration = 8 * ToSendMax;
 787                 }
 788                 b >>= 1;
 789         }
 790
 791         // Send stopbit
 792         ToSend[++ToSendMax] = SEC_F;
 793
 794         // Convert from last byte pos to length
 795         ToSendMax++;
 796 }
 797
 798 //-----------------------------------------------------------------------------
 799 // Wait for commands from reader
 800 // Stop when button is pressed
 801 // Or return TRUE when command is captured
 802 //-----------------------------------------------------------------------------
 803 static int GetIso14443aCommandFromReader(uint8_t *received, uint8_t *parity, int *len)
 804 {
 805     // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
 806     // only, since we are receiving, not transmitting).
 807     // Signal field is off with the appropriate LED
 808     LED_D_OFF();
 809     FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
 810
 811     // Now run a `software UART' on the stream of incoming samples.
 812         UartInit(received, parity);
 813
 814         // clear RXRDY:
 815     uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
 816
 817     for(;;) {
 818         WDT_HIT();
 819
 820         if(BUTTON_PRESS()) return FALSE;
 821
 822         if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
 823             b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
 824                         if(MillerDecoding(b, 0)) {
 825                                 *len = Uart.len;
 826                                 return TRUE;
 827                         }
 828                 }
 829     }
 830 }
 831
 832 static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded);
 833 int EmSend4bitEx(uint8_t resp, bool correctionNeeded);
 834 int EmSend4bit(uint8_t resp);
 835 int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par);
 836 int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded);
 837 int EmSendCmd(uint8_t *resp, uint16_t respLen);
 838 int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par);
 839 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
 840                                  uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity);
 841
 842 static uint8_t* free_buffer_pointer;
 843
 844 typedef struct {
 845   uint8_t* response;
 846   size_t   response_n;
 847   uint8_t* modulation;
 848   size_t   modulation_n;
 849   uint32_t ProxToAirDuration;
 850 } tag_response_info_t;
 851
 852 bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) {
 853         // Example response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes
 854         // This will need the following byte array for a modulation sequence
 855         //    144        data bits (18 * 8)
 856         //     18        parity bits
 857         //      2        Start and stop
 858         //      1        Correction bit (Answer in 1172 or 1236 periods, see FPGA)
 859         //      1        just for the case
 860         // ----------- +
 861         //    166 bytes, since every bit that needs to be send costs us a byte
 862         //
 863
 864
 865   // Prepare the tag modulation bits from the message
 866   CodeIso14443aAsTag(response_info->response,response_info->response_n);
 867
 868   // Make sure we do not exceed the free buffer space
 869   if (ToSendMax > max_buffer_size) {
 870     Dbprintf("Out of memory, when modulating bits for tag answer:");
 871     Dbhexdump(response_info->response_n,response_info->response,false);
 872     return false;
 873   }
 874
 875   // Copy the byte array, used for this modulation to the buffer position
 876   memcpy(response_info->modulation,ToSend,ToSendMax);
 877
 878   // Store the number of bytes that were used for encoding/modulation and the time needed to transfer them
 879   response_info->modulation_n = ToSendMax;
 880   response_info->ProxToAirDuration = LastProxToAirDuration;
 881
 882   return true;
 883 }
 884
 885
 886 // "precompile" responses. There are 7 predefined responses with a total of 28 bytes data to transmit.
 887 // Coded responses need one byte per bit to transfer (data, parity, start, stop, correction)
 888 // 28 * 8 data bits, 28 * 1 parity bits, 7 start bits, 7 stop bits, 7 correction bits
 889 // -> need 273 bytes buffer
 890 // 44 * 8 data bits, 44 * 1 parity bits, 9 start bits, 9 stop bits, 9 correction bits --370
 891 // 47 * 8 data bits, 47 * 1 parity bits, 10 start bits, 10 stop bits, 10 correction bits
 892 #define ALLOCATED_TAG_MODULATION_BUFFER_SIZE 453
 893
 894 bool prepare_allocated_tag_modulation(tag_response_info_t* response_info) {
 895   // Retrieve and store the current buffer index
 896   response_info->modulation = free_buffer_pointer;
 897
 898   // Determine the maximum size we can use from our buffer
 899   size_t max_buffer_size = ALLOCATED_TAG_MODULATION_BUFFER_SIZE;
 900
 901   // Forward the prepare tag modulation function to the inner function
 902   if (prepare_tag_modulation(response_info, max_buffer_size)) {
 903     // Update the free buffer offset
 904     free_buffer_pointer += ToSendMax;
 905     return true;
 906   } else {
 907     return false;
 908   }
 909 }
 910
 911 //-----------------------------------------------------------------------------
 912 // Main loop of simulated tag: receive commands from reader, decide what
 913 // response to send, and send it.
 914 //-----------------------------------------------------------------------------
 915 void SimulateIso14443aTag(int tagType, int flags, byte_t* data)
 916 {
 917         uint32_t counters[] = {0,0,0};
 918         //Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2
 919         // This can be used in a reader-only attack.
 920         // (it can also be retrieved via 'hf 14a list', but hey...
 921         uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0,0,0};
 922         uint8_t ar_nr_collected = 0;
 923
 924         uint8_t sak;
 925
 926         // PACK response to PWD AUTH for EV1/NTAG
 927         uint8_t response8[4] =  {0,0,0,0};
 928
 929         // The first response contains the ATQA (note: bytes are transmitted in reverse order).
 930         uint8_t response1[2] =  {0,0};
 931
 932         switch (tagType) {
 933                 case 1: { // MIFARE Classic
 934                         // Says: I am Mifare 1k - original line
 935                         response1[0] = 0x04;
 936                         response1[1] = 0x00;
 937                         sak = 0x08;
 938                 } break;
 939                 case 2: { // MIFARE Ultralight
 940                         // Says: I am a stupid memory tag, no crypto
 941                         response1[0] = 0x44;
 942                         response1[1] = 0x00;
 943                         sak = 0x00;
 944                 } break;
 945                 case 3: { // MIFARE DESFire
 946                         // Says: I am a DESFire tag, ph33r me
 947                         response1[0] = 0x04;
 948                         response1[1] = 0x03;
 949                         sak = 0x20;
 950                 } break;
 951                 case 4: { // ISO/IEC 14443-4
 952                         // Says: I am a javacard (JCOP)
 953                         response1[0] = 0x04;
 954                         response1[1] = 0x00;
 955                         sak = 0x28;
 956                 } break;
 957                 case 5: { // MIFARE TNP3XXX
 958                         // Says: I am a toy
 959                         response1[0] = 0x01;
 960                         response1[1] = 0x0f;
 961                         sak = 0x01;
 962                 } break;
 963                 case 6: { // MIFARE Mini
 964                         // Says: I am a Mifare Mini, 320b
 965                         response1[0] = 0x44;
 966                         response1[1] = 0x00;
 967                         sak = 0x09;
 968                 } break;
 969                 case 7: { // NTAG?
 970                         // Says: I am a NTAG,
 971                         response1[0] = 0x44;
 972                         response1[1] = 0x00;
 973                         sak = 0x00;
 974                         // PACK
 975                         response8[0] = 0x80;
 976                         response8[1] = 0x80;
 977                         ComputeCrc14443(CRC_14443_A, response8, 2, &response8[2], &response8[3]);
 978                         // uid not supplied then get from emulator memory
 979                         if (data[0]==0) {
 980                                 uint16_t start = 4 * (0+12);
 981                                 uint8_t emdata[8];
 982                                 emlGetMemBt( emdata, start, sizeof(emdata));
 983                                 memcpy(data, emdata, 3); //uid bytes 0-2
 984                                 memcpy(data+3, emdata+4, 4); //uid bytes 3-7
 985                                 flags |= FLAG_7B_UID_IN_DATA;
 986                         }
 987                 } break;
 988                 default: {
 989                         Dbprintf("Error: unkown tagtype (%d)",tagType);
 990                         return;
 991                 } break;
 992         }
 993
 994         // The second response contains the (mandatory) first 24 bits of the UID
 995         uint8_t response2[5] = {0x00};
 996
 997         // Check if the uid uses the (optional) part
 998         uint8_t response2a[5] = {0x00};
 999
1000         if (flags & FLAG_7B_UID_IN_DATA) {
1001                 response2[0] = 0x88;
1002                 response2[1] = data[0];
1003                 response2[2] = data[1];
1004                 response2[3] = data[2];
1005
1006                 response2a[0] = data[3];
1007                 response2a[1] = data[4];
1008                 response2a[2] = data[5];
1009                 response2a[3] = data[6]; //??
1010                 response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3];
1011
1012                 // Configure the ATQA and SAK accordingly
1013                 response1[0] |= 0x40;
1014                 sak |= 0x04;
1015         } else {
1016                 memcpy(response2, data, 4);
1017                 //num_to_bytes(uid_1st,4,response2);
1018                 // Configure the ATQA and SAK accordingly
1019                 response1[0] &= 0xBF;
1020                 sak &= 0xFB;
1021         }
1022
1023         // Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID.
1024         response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3];
1025
1026         // Prepare the mandatory SAK (for 4 and 7 byte UID)
1027         uint8_t response3[3]  = {0x00};
1028         response3[0] = sak;
1029         ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
1030
1031         // Prepare the optional second SAK (for 7 byte UID), drop the cascade bit
1032         uint8_t response3a[3]  = {0x00};
1033         response3a[0] = sak & 0xFB;
1034         ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
1035
1036         uint8_t response5[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce
1037         uint8_t response6[] = { 0x04, 0x58, 0x80, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS:
1038         // Format byte = 0x58: FSCI=0x08 (FSC=256), TA(1) and TC(1) present,
1039         // TA(1) = 0x80: different divisors not supported, DR = 1, DS = 1
1040         // 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)
1041         // TC(1) = 0x02: CID supported, NAD not supported
1042         ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]);
1043
1044         // Prepare GET_VERSION (different for UL EV-1 / NTAG)
1045         //uint8_t response7_EV1[] = {0x00, 0x04, 0x03, 0x01, 0x01, 0x00, 0x0b, 0x03, 0xfd, 0xf7};  //EV1 48bytes VERSION.
1046         //uint8_t response7_NTAG[] = {0x00, 0x04, 0x04, 0x02, 0x01, 0x00, 0x11, 0x03, 0x01, 0x9e}; //NTAG 215
1047
1048         // Prepare CHK_TEARING
1049         //uint8_t response9[] =  {0xBD,0x90,0x3f};
1050
1051         #define TAG_RESPONSE_COUNT 10
1052         tag_response_info_t responses[TAG_RESPONSE_COUNT] = {
1053                 { .response = response1,  .response_n = sizeof(response1)  },  // Answer to request - respond with card type
1054                 { .response = response2,  .response_n = sizeof(response2)  },  // Anticollision cascade1 - respond with uid
1055                 { .response = response2a, .response_n = sizeof(response2a) },  // Anticollision cascade2 - respond with 2nd half of uid if asked
1056                 { .response = response3,  .response_n = sizeof(response3)  },  // Acknowledge select - cascade 1
1057                 { .response = response3a, .response_n = sizeof(response3a) },  // Acknowledge select - cascade 2
1058                 { .response = response5,  .response_n = sizeof(response5)  },  // Authentication answer (random nonce)
1059                 { .response = response6,  .response_n = sizeof(response6)  },  // dummy ATS (pseudo-ATR), answer to RATS
1060
1061                 { .response = response8,   .response_n = sizeof(response8) }  // EV1/NTAG PACK response
1062         };
1063                 //{ .response = response7_NTAG, .response_n = sizeof(response7_NTAG)}, // EV1/NTAG GET_VERSION response
1064                 //{ .response = response9,      .response_n = sizeof(response9)     }  // EV1/NTAG CHK_TEAR response
1065
1066
1067         // Allocate 512 bytes for the dynamic modulation, created when the reader queries for it
1068         // Such a response is less time critical, so we can prepare them on the fly
1069         #define DYNAMIC_RESPONSE_BUFFER_SIZE 64
1070         #define DYNAMIC_MODULATION_BUFFER_SIZE 512
1071         uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
1072         uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
1073         tag_response_info_t dynamic_response_info = {
1074                 .response = dynamic_response_buffer,
1075                 .response_n = 0,
1076                 .modulation = dynamic_modulation_buffer,
1077                 .modulation_n = 0
1078         };
1079
1080         // We need to listen to the high-frequency, peak-detected path.
1081         iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1082
1083         BigBuf_free_keep_EM();
1084
1085         // allocate buffers:
1086         uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
1087         uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
1088         free_buffer_pointer = BigBuf_malloc(ALLOCATED_TAG_MODULATION_BUFFER_SIZE);
1089
1090         // clear trace
1091         clear_trace();
1092         set_tracing(TRUE);
1093
1094         // Prepare the responses of the anticollision phase
1095         // there will be not enough time to do this at the moment the reader sends it REQA
1096         for (size_t i=0; i<TAG_RESPONSE_COUNT; i++)
1097                 prepare_allocated_tag_modulation(&responses[i]);
1098
1099         int len = 0;
1100
1101         // To control where we are in the protocol
1102         int order = 0;
1103         int lastorder;
1104
1105         // Just to allow some checks
1106         int happened = 0;
1107         int happened2 = 0;
1108         int cmdsRecvd = 0;
1109
1110         cmdsRecvd = 0;
1111         tag_response_info_t* p_response;
1112
1113         LED_A_ON();
1114         for(;;) {
1115
1116                 WDT_HIT();
1117
1118                 // Clean receive command buffer
1119                 if(!GetIso14443aCommandFromReader(receivedCmd, receivedCmdPar, &len)) {
1120                         DbpString("Button press");
1121                         break;
1122                 }
1123
1124                 p_response = NULL;
1125
1126                 // Okay, look at the command now.
1127                 lastorder = order;
1128                 if(receivedCmd[0] == 0x26) { // Received a REQUEST
1129                         p_response = &responses[0]; order = 1;
1130                 } else if(receivedCmd[0] == 0x52) { // Received a WAKEUP
1131                         p_response = &responses[0]; order = 6;
1132                 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) {   // Received request for UID (cascade 1)
1133                         p_response = &responses[1]; order = 2;
1134                 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x95) {   // Received request for UID (cascade 2)
1135                         p_response = &responses[2]; order = 20;
1136                 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x93) {   // Received a SELECT (cascade 1)
1137                         p_response = &responses[3]; order = 3;
1138                 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x95) {   // Received a SELECT (cascade 2)
1139                         p_response = &responses[4]; order = 30;
1140                 } else if(receivedCmd[0] == 0x30) {     // Received a (plain) READ
1141                         uint8_t block = receivedCmd[1];
1142                         // if Ultralight or NTAG (4 byte blocks)
1143                         if ( tagType == 7 || tagType == 2 ) {
1144                                 //first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1145                                 uint16_t start = 4 * (block+12);
1146                                         uint8_t emdata[MAX_MIFARE_FRAME_SIZE];
1147                                         emlGetMemBt( emdata, start, 16);
1148                                         AppendCrc14443a(emdata, 16);
1149                                         EmSendCmdEx(emdata, sizeof(emdata), false);
1150                                 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1151                                 p_response = NULL;
1152                         } else { // all other tags (16 byte block tags)
1153                                 EmSendCmdEx(data+(4*receivedCmd[1]),16,false);
1154                                 // Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
1155                                 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1156                                 p_response = NULL;
1157                         }
1158                 } else if(receivedCmd[0] == 0x3A) {     // Received a FAST READ (ranged read)
1159
1160                                 uint8_t emdata[MAX_FRAME_SIZE];
1161                                 //first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1162                                 int start =  (receivedCmd[1]+12) * 4;
1163                                 int len   = (receivedCmd[2] - receivedCmd[1] + 1) * 4;
1164                                 emlGetMemBt( emdata, start, len);
1165                                 AppendCrc14443a(emdata, len);
1166                                 EmSendCmdEx(emdata, len+2, false);
1167                                 p_response = NULL;
1168
1169                 } else if(receivedCmd[0] == 0x3C && tagType == 7) {     // Received a READ SIGNATURE --
1170                                 // ECC data,  taken from a NTAG215 amiibo token. might work. LEN: 32, + 2 crc
1171                                 //first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1172                                 uint16_t start = 4 * 4;
1173                                 uint8_t emdata[34];
1174                                 emlGetMemBt( emdata, start, 32);
1175                                 AppendCrc14443a(emdata, 32);
1176                                 EmSendCmdEx(emdata, sizeof(emdata), false);
1177                                 //uint8_t data[] = {0x56,0x06,0xa6,0x4f,0x43,0x32,0x53,0x6f,
1178                                 //                                0x43,0xda,0x45,0xd6,0x61,0x38,0xaa,0x1e,
1179                                 //                                0xcf,0xd3,0x61,0x36,0xca,0x5f,0xbb,0x05,
1180                                 //                                0xce,0x21,0x24,0x5b,0xa6,0x7a,0x79,0x07,
1181                                 //                                0x00,0x00};
1182                                 //AppendCrc14443a(data, sizeof(data)-2);
1183                                 //EmSendCmdEx(data,sizeof(data),false);
1184                                 p_response = NULL;
1185                 } else if (receivedCmd[0] == 0x39 && tagType == 7) {    // Received a READ COUNTER --
1186                         uint8_t index = receivedCmd[1];
1187                         uint8_t data[] =  {0x00,0x00,0x00,0x14,0xa5};
1188                         if ( counters[index] > 0) {
1189                                 num_to_bytes(counters[index], 3, data);
1190                                 AppendCrc14443a(data, sizeof(data)-2);
1191                         }
1192                         EmSendCmdEx(data,sizeof(data),false);
1193                         p_response = NULL;
1194                 } else if (receivedCmd[0] == 0xA5 && tagType == 7) {    // Received a INC COUNTER --
1195                         // number of counter
1196                         uint8_t counter = receivedCmd[1];
1197                         uint32_t val = bytes_to_num(receivedCmd+2,4);
1198                         counters[counter] = val;
1199
1200                         // send ACK
1201                         uint8_t ack[] = {0x0a};
1202                         EmSendCmdEx(ack,sizeof(ack),false);
1203                         p_response = NULL;
1204
1205                 } else if(receivedCmd[0] == 0x3E && tagType == 7) {     // Received a CHECK_TEARING_EVENT --
1206                         //first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1207                         uint8_t emdata[3];
1208                         uint8_t counter=0;
1209                         if (receivedCmd[1]<3) counter = receivedCmd[1];
1210                         emlGetMemBt( emdata, 10+counter, 1);
1211                         AppendCrc14443a(emdata, sizeof(emdata)-2);
1212                         EmSendCmdEx(emdata, sizeof(emdata), false);
1213                         p_response = NULL;
1214                         //p_response = &responses[9];
1215
1216                 } else if(receivedCmd[0] == 0x50) {     // Received a HALT
1217                         LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1218                         p_response = NULL;
1219                 } else if(receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61) {   // Received an authentication request
1220
1221                         if ( tagType == 7 ) {   // IF NTAG /EV1  0x60 == GET_VERSION, not a authentication request.
1222                                 uint8_t emdata[10];
1223                                 emlGetMemBt( emdata, 0, 8 );
1224                                 AppendCrc14443a(emdata, sizeof(emdata)-2);
1225                                 EmSendCmdEx(emdata, sizeof(emdata), false);
1226                                 p_response = NULL;
1227                                 //p_response = &responses[7];
1228                         } else {
1229                                 p_response = &responses[5]; order = 7;
1230                         }
1231                 } else if(receivedCmd[0] == 0xE0) {     // Received a RATS request
1232                         if (tagType == 1 || tagType == 2) {     // RATS not supported
1233                                 EmSend4bit(CARD_NACK_NA);
1234                                 p_response = NULL;
1235                         } else {
1236                                 p_response = &responses[6]; order = 70;
1237                         }
1238                 } else if (order == 7 && len == 8) { // Received {nr] and {ar} (part of authentication)
1239                         LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1240                         uint32_t nonce = bytes_to_num(response5,4);
1241                         uint32_t nr = bytes_to_num(receivedCmd,4);
1242                         uint32_t ar = bytes_to_num(receivedCmd+4,4);
1243                         //Dbprintf("Auth attempt {nonce}{nr}{ar}: %08x %08x %08x", nonce, nr, ar);
1244
1245                         if(flags & FLAG_NR_AR_ATTACK )
1246                         {
1247                                 if(ar_nr_collected < 2){
1248                                         // Avoid duplicates... probably not necessary, nr should vary.
1249                                         //if(ar_nr_responses[3] != nr){
1250                                                 ar_nr_responses[ar_nr_collected*5]   = 0;
1251                                                 ar_nr_responses[ar_nr_collected*5+1] = 0;
1252                                                 ar_nr_responses[ar_nr_collected*5+2] = nonce;
1253                                                 ar_nr_responses[ar_nr_collected*5+3] = nr;
1254                                                 ar_nr_responses[ar_nr_collected*5+4] = ar;
1255                                                 ar_nr_collected++;
1256                                         //}
1257                                 }
1258
1259                                 if(ar_nr_collected > 1 ) {
1260
1261                                         if (MF_DBGLEVEL >= 2) {
1262                                                         Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
1263                                                         Dbprintf("../tools/mfkey/mfkey32 %07x%08x %08x %08x %08x %08x %08x",
1264                                                                 ar_nr_responses[0], // UID1
1265                                                                 ar_nr_responses[1], // UID2
1266                                                                 ar_nr_responses[2], // NT
1267                                                                 ar_nr_responses[3], // AR1
1268                                                                 ar_nr_responses[4], // NR1
1269                                                                 ar_nr_responses[8], // AR2
1270                                                                 ar_nr_responses[9]  // NR2
1271                                                         );
1272                                                         Dbprintf("../tools/mfkey/mfkey32v2 %06x%08x %08x %08x %08x %08x %08x %08x",
1273                                                                 ar_nr_responses[0], // UID1
1274                                                                 ar_nr_responses[1], // UID2
1275                                                                 ar_nr_responses[2], // NT1
1276                                                                 ar_nr_responses[3], // AR1
1277                                                                 ar_nr_responses[4], // NR1
1278                                                                 ar_nr_responses[7], // NT2
1279                                                                 ar_nr_responses[8], // AR2
1280                                                                 ar_nr_responses[9]  // NR2
1281                                                                 );
1282                                         }
1283                                         uint8_t len = ar_nr_collected*5*4;
1284                                         cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,len,0,&ar_nr_responses,len);
1285                                         ar_nr_collected = 0;
1286                                         memset(ar_nr_responses, 0x00, len);
1287                                 }
1288                         }
1289                 } else if (receivedCmd[0] == 0x1a ) // ULC authentication
1290                 {
1291
1292                 }
1293                 else if (receivedCmd[0] == 0x1b) // NTAG / EV-1 authentication
1294                 {
1295                         if ( tagType == 7 ) {
1296                                 uint16_t start = 13; //first 4 blocks of emu are [getversion answer - check tearing - pack - 0x00]
1297                                 uint8_t emdata[4];
1298                                 emlGetMemBt( emdata, start, 2);
1299                                 AppendCrc14443a(emdata, 2);
1300                                 EmSendCmdEx(emdata, sizeof(emdata), false);
1301                                 p_response = NULL;
1302                                 //p_response =  &responses[8]; // PACK response
1303                                 uint32_t pwd = bytes_to_num(receivedCmd+1,4);
1304
1305                                 if ( MF_DBGLEVEL >= 3)  Dbprintf("Auth attempt: %08x", pwd);
1306                         }
1307                 } else {
1308                         // Check for ISO 14443A-4 compliant commands, look at left nibble
1309                         switch (receivedCmd[0]) {
1310                                 case 0x02:
1311                                 case 0x03: {  // IBlock (command no CID)
1312                                         dynamic_response_info.response[0] = receivedCmd[0];
1313                                         dynamic_response_info.response[1] = 0x90;
1314                                         dynamic_response_info.response[2] = 0x00;
1315                                         dynamic_response_info.response_n = 3;
1316                                 } break;
1317                                 case 0x0B:
1318                                 case 0x0A: { // IBlock (command CID)
1319                                   dynamic_response_info.response[0] = receivedCmd[0];
1320                                   dynamic_response_info.response[1] = 0x00;
1321                                   dynamic_response_info.response[2] = 0x90;
1322                                   dynamic_response_info.response[3] = 0x00;
1323                                   dynamic_response_info.response_n = 4;
1324                                 } break;
1325
1326                                 case 0x1A:
1327                                 case 0x1B: { // Chaining command
1328                                   dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1);
1329                                   dynamic_response_info.response_n = 2;
1330                                 } break;
1331
1332                                 case 0xaa:
1333                                 case 0xbb: {
1334                                   dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11;
1335                                   dynamic_response_info.response_n = 2;
1336                                 } break;
1337
1338                                 case 0xBA: { // ping / pong
1339                                         dynamic_response_info.response[0] = 0xAB;
1340                                         dynamic_response_info.response[1] = 0x00;
1341                                         dynamic_response_info.response_n = 2;
1342                                 } break;
1343
1344                                 case 0xCA:
1345                                 case 0xC2: { // Readers sends deselect command
1346                                         dynamic_response_info.response[0] = 0xCA;
1347                                         dynamic_response_info.response[1] = 0x00;
1348                                         dynamic_response_info.response_n = 2;
1349                                 } break;
1350
1351                                 default: {
1352                                         // Never seen this command before
1353                                         LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1354                                         Dbprintf("Received unknown command (len=%d):",len);
1355                                         Dbhexdump(len,receivedCmd,false);
1356                                         // Do not respond
1357                                         dynamic_response_info.response_n = 0;
1358                                 } break;
1359                         }
1360
1361                         if (dynamic_response_info.response_n > 0) {
1362                                 // Copy the CID from the reader query
1363                                 dynamic_response_info.response[1] = receivedCmd[1];
1364
1365                                 // Add CRC bytes, always used in ISO 14443A-4 compliant cards
1366                                 AppendCrc14443a(dynamic_response_info.response,dynamic_response_info.response_n);
1367                                 dynamic_response_info.response_n += 2;
1368
1369                                 if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) {
1370                                         Dbprintf("Error preparing tag response");
1371                                         LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1372                                         break;
1373                                 }
1374                                 p_response = &dynamic_response_info;
1375                         }
1376                 }
1377
1378                 // Count number of wakeups received after a halt
1379                 if(order == 6 && lastorder == 5) { happened++; }
1380
1381                 // Count number of other messages after a halt
1382                 if(order != 6 && lastorder == 5) { happened2++; }
1383
1384                 if(cmdsRecvd > 999) {
1385                         DbpString("1000 commands later...");
1386                         break;
1387                 }
1388                 cmdsRecvd++;
1389
1390                 if (p_response != NULL) {
1391                         EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52);
1392                         // do the tracing for the previous reader request and this tag answer:
1393                         uint8_t par[MAX_PARITY_SIZE] = {0x00};
1394                         GetParity(p_response->response, p_response->response_n, par);
1395
1396                         EmLogTrace(Uart.output,
1397                                                 Uart.len,
1398                                                 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1399                                                 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1400                                                 Uart.parity,
1401                                                 p_response->response,
1402                                                 p_response->response_n,
1403                                                 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1404                                                 (LastTimeProxToAirStart + p_response->ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1405                                                 par);
1406                 }
1407
1408                 if (!tracing) {
1409                         Dbprintf("Trace Full. Simulation stopped.");
1410                         break;
1411                 }
1412         }
1413
1414         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
1415         set_tracing(FALSE);
1416         BigBuf_free_keep_EM();
1417         LED_A_OFF();
1418
1419         if (MF_DBGLEVEL >= 4){
1420                 Dbprintf("-[ Wake ups after halt [%d]", happened);
1421                 Dbprintf("-[ Messages after halt [%d]", happened2);
1422                 Dbprintf("-[ Num of received cmd [%d]", cmdsRecvd);
1423         }
1424 }
1425
1426
1427 // prepare a delayed transfer. This simply shifts ToSend[] by a number
1428 // of bits specified in the delay parameter.
1429 void PrepareDelayedTransfer(uint16_t delay)
1430 {
1431         uint8_t bitmask = 0;
1432         uint8_t bits_to_shift = 0;
1433         uint8_t bits_shifted = 0;
1434
1435         delay &= 0x07;
1436         if (delay) {
1437                 for (uint16_t i = 0; i < delay; i++) {
1438                         bitmask |= (1 << i);
1439                 }
1440                 ToSend[++ToSendMax] = 0x00;
1441                 for (uint16_t i = 0; i < ToSendMax; i++) {
1442                         bits_to_shift = ToSend[i] & bitmask;
1443                         ToSend[i] = ToSend[i] >> delay;
1444                         ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay));
1445                         bits_shifted = bits_to_shift;
1446                 }
1447         }
1448 }
1449
1450
1451 //-------------------------------------------------------------------------------------
1452 // Transmit the command (to the tag) that was placed in ToSend[].
1453 // Parameter timing:
1454 // if NULL: transfer at next possible time, taking into account
1455 //                      request guard time and frame delay time
1456 // if == 0:     transfer immediately and return time of transfer
1457 // if != 0: delay transfer until time specified
1458 //-------------------------------------------------------------------------------------
1459 static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing)
1460 {
1461         FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
1462
1463         uint32_t ThisTransferTime = 0;
1464
1465         if (timing) {
1466                 if(*timing == 0) {                                                                              // Measure time
1467                         *timing = (GetCountSspClk() + 8) & 0xfffffff8;
1468                 } else {
1469                         PrepareDelayedTransfer(*timing & 0x00000007);           // Delay transfer (fine tuning - up to 7 MF clock ticks)
1470                 }
1471                 if(MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
1472
1473                 while(GetCountSspClk() < (*timing & 0xfffffff8));               // Delay transfer (multiple of 8 MF clock ticks)
1474                 LastTimeProxToAirStart = *timing;
1475         } else {
1476                 ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8);
1477                 while(GetCountSspClk() < ThisTransferTime);
1478                 LastTimeProxToAirStart = ThisTransferTime;
1479         }
1480
1481         // clear TXRDY
1482         AT91C_BASE_SSC->SSC_THR = SEC_Y;
1483
1484         uint16_t c = 0;
1485         for(;;) {
1486                 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1487                         AT91C_BASE_SSC->SSC_THR = cmd[c];
1488                         ++c;
1489                         if(c >= len)
1490                                 break;
1491                 }
1492         }
1493
1494         NextTransferTime = MAX(NextTransferTime, LastTimeProxToAirStart + REQUEST_GUARD_TIME);
1495 }
1496
1497
1498 //-----------------------------------------------------------------------------
1499 // Prepare reader command (in bits, support short frames) to send to FPGA
1500 //-----------------------------------------------------------------------------
1501 void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8_t *parity)
1502 {
1503         int i, j;
1504         int last = 0;
1505         uint8_t b;
1506
1507         ToSendReset();
1508
1509         // Start of Communication (Seq. Z)
1510         ToSend[++ToSendMax] = SEC_Z;
1511         LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1512
1513         size_t bytecount = nbytes(bits);
1514         // Generate send structure for the data bits
1515         for (i = 0; i < bytecount; i++) {
1516                 // Get the current byte to send
1517                 b = cmd[i];
1518                 size_t bitsleft = MIN((bits-(i*8)),8);
1519
1520                 for (j = 0; j < bitsleft; j++) {
1521                         if (b & 1) {
1522                                 // Sequence X
1523                                 ToSend[++ToSendMax] = SEC_X;
1524                                 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1525                                 last = 1;
1526                         } else {
1527                                 if (last == 0) {
1528                                 // Sequence Z
1529                                 ToSend[++ToSendMax] = SEC_Z;
1530                                 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1531                                 } else {
1532                                         // Sequence Y
1533                                         ToSend[++ToSendMax] = SEC_Y;
1534                                         last = 0;
1535                                 }
1536                         }
1537                         b >>= 1;
1538                 }
1539
1540                 // Only transmit parity bit if we transmitted a complete byte
1541                 if (j == 8 && parity != NULL) {
1542                         // Get the parity bit
1543                         if (parity[i>>3] & (0x80 >> (i&0x0007))) {
1544                                 // Sequence X
1545                                 ToSend[++ToSendMax] = SEC_X;
1546                                 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1547                                 last = 1;
1548                         } else {
1549                                 if (last == 0) {
1550                                         // Sequence Z
1551                                         ToSend[++ToSendMax] = SEC_Z;
1552                                         LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1553                                 } else {
1554                                         // Sequence Y
1555                                         ToSend[++ToSendMax] = SEC_Y;
1556                                         last = 0;
1557                                 }
1558                         }
1559                 }
1560         }
1561
1562         // End of Communication: Logic 0 followed by Sequence Y
1563         if (last == 0) {
1564                 // Sequence Z
1565                 ToSend[++ToSendMax] = SEC_Z;
1566                 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1567         } else {
1568                 // Sequence Y
1569                 ToSend[++ToSendMax] = SEC_Y;
1570                 last = 0;
1571         }
1572         ToSend[++ToSendMax] = SEC_Y;
1573
1574         // Convert to length of command:
1575         ++ToSendMax;
1576 }
1577
1578 //-----------------------------------------------------------------------------
1579 // Prepare reader command to send to FPGA
1580 //-----------------------------------------------------------------------------
1581 void CodeIso14443aAsReaderPar(const uint8_t *cmd, uint16_t len, const uint8_t *parity)
1582 {
1583   //CodeIso14443aBitsAsReaderPar(cmd, len*8, parity);
1584   CodeIso14443aBitsAsReaderPar(cmd, len<<3, parity);
1585 }
1586
1587
1588 //-----------------------------------------------------------------------------
1589 // Wait for commands from reader
1590 // Stop when button is pressed (return 1) or field was gone (return 2)
1591 // Or return 0 when command is captured
1592 //-----------------------------------------------------------------------------
1593 static int EmGetCmd(uint8_t *received, uint16_t *len, uint8_t *parity)
1594 {
1595         *len = 0;
1596
1597         uint32_t timer = 0, vtime = 0;
1598         int analogCnt = 0;
1599         int analogAVG = 0;
1600
1601         // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
1602         // only, since we are receiving, not transmitting).
1603         // Signal field is off with the appropriate LED
1604         LED_D_OFF();
1605         FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1606
1607         // Set ADC to read field strength
1608         AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST;
1609         AT91C_BASE_ADC->ADC_MR =
1610                                 ADC_MODE_PRESCALE(63) |
1611                                 ADC_MODE_STARTUP_TIME(1) |
1612                                 ADC_MODE_SAMPLE_HOLD_TIME(15);
1613         AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF);
1614         // start ADC
1615         AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1616
1617         // Now run a 'software UART' on the stream of incoming samples.
1618         UartInit(received, parity);
1619
1620         // Clear RXRDY:
1621     uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1622
1623         for(;;) {
1624                 WDT_HIT();
1625
1626                 if (BUTTON_PRESS()) return 1;
1627
1628                 // test if the field exists
1629                 if (AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ADC_CHAN_HF)) {
1630                         analogCnt++;
1631                         analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF];
1632                         AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1633                         if (analogCnt >= 32) {
1634                                 if ((MAX_ADC_HF_VOLTAGE * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) {
1635                                         vtime = GetTickCount();
1636                                         if (!timer) timer = vtime;
1637                                         // 50ms no field --> card to idle state
1638                                         if (vtime - timer > 50) return 2;
1639                                 } else
1640                                         if (timer) timer = 0;
1641                                 analogCnt = 0;
1642                                 analogAVG = 0;
1643                         }
1644                 }
1645
1646                 // receive and test the miller decoding
1647         if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1648             b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1649                         if(MillerDecoding(b, 0)) {
1650                                 *len = Uart.len;
1651                                 return 0;
1652                         }
1653         }
1654
1655         }
1656 }
1657
1658
1659 static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded)
1660 {
1661         uint8_t b;
1662         uint16_t i = 0;
1663         uint32_t ThisTransferTime;
1664
1665         // Modulate Manchester
1666         FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
1667
1668         // include correction bit if necessary
1669         if (Uart.parityBits & 0x01) {
1670                 correctionNeeded = TRUE;
1671         }
1672         if(correctionNeeded) {
1673                 // 1236, so correction bit needed
1674                 i = 0;
1675         } else {
1676                 i = 1;
1677         }
1678
1679         // clear receiving shift register and holding register
1680         while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1681         b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1682         while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1683         b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1684
1685         // wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line)
1686         for (uint16_t j = 0; j < 5; j++) {      // allow timeout - better late than never
1687                 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1688                 if (AT91C_BASE_SSC->SSC_RHR) break;
1689         }
1690
1691         while ((ThisTransferTime = GetCountSspClk()) & 0x00000007);
1692
1693         // Clear TXRDY:
1694         AT91C_BASE_SSC->SSC_THR = SEC_F;
1695
1696         // send cycle
1697         for(; i < respLen; ) {
1698                 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1699                         AT91C_BASE_SSC->SSC_THR = resp[i++];
1700                         FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1701                 }
1702
1703                 if(BUTTON_PRESS()) break;
1704         }
1705
1706         // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
1707         uint8_t fpga_queued_bits = FpgaSendQueueDelay >> 3;  // twich /8 ??   >>3,
1708         for (i = 0; i <= fpga_queued_bits/8 + 1; ) {
1709                 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1710                         AT91C_BASE_SSC->SSC_THR = SEC_F;
1711                         FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1712                         i++;
1713                 }
1714         }
1715
1716         LastTimeProxToAirStart = ThisTransferTime + (correctionNeeded?8:0);
1717
1718         return 0;
1719 }
1720
1721 int EmSend4bitEx(uint8_t resp, bool correctionNeeded){
1722         Code4bitAnswerAsTag(resp);
1723         int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1724         // do the tracing for the previous reader request and this tag answer:
1725         uint8_t par[1] = {0x00};
1726         GetParity(&resp, 1, par);
1727         EmLogTrace(Uart.output,
1728                                 Uart.len,
1729                                 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1730                                 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1731                                 Uart.parity,
1732                                 &resp,
1733                                 1,
1734                                 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1735                                 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1736                                 par);
1737         return res;
1738 }
1739
1740 int EmSend4bit(uint8_t resp){
1741         return EmSend4bitEx(resp, false);
1742 }
1743
1744 int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par){
1745         CodeIso14443aAsTagPar(resp, respLen, par);
1746         int res = EmSendCmd14443aRaw(ToSend, ToSendMax, correctionNeeded);
1747         // do the tracing for the previous reader request and this tag answer:
1748         EmLogTrace(Uart.output,
1749                                 Uart.len,
1750                                 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1751                                 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1752                                 Uart.parity,
1753                                 resp,
1754                                 respLen,
1755                                 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1756                                 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1757                                 par);
1758         return res;
1759 }
1760
1761 int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded){
1762         uint8_t par[MAX_PARITY_SIZE] = {0x00};
1763         GetParity(resp, respLen, par);
1764         return EmSendCmdExPar(resp, respLen, correctionNeeded, par);
1765 }
1766
1767 int EmSendCmd(uint8_t *resp, uint16_t respLen){
1768         uint8_t par[MAX_PARITY_SIZE] = {0x00};
1769         GetParity(resp, respLen, par);
1770         return EmSendCmdExPar(resp, respLen, false, par);
1771 }
1772
1773 int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par){
1774         return EmSendCmdExPar(resp, respLen, false, par);
1775 }
1776
1777 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
1778                                  uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity)
1779 {
1780         // we cannot exactly measure the end and start of a received command from reader. However we know that the delay from
1781         // end of the received command to start of the tag's (simulated by us) answer is n*128+20 or n*128+84 resp.
1782         // with n >= 9. The start of the tags answer can be measured and therefore the end of the received command be calculated:
1783         uint16_t reader_modlen = reader_EndTime - reader_StartTime;
1784         uint16_t approx_fdt = tag_StartTime - reader_EndTime;
1785         uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20;
1786         reader_EndTime = tag_StartTime - exact_fdt;
1787         reader_StartTime = reader_EndTime - reader_modlen;
1788
1789         if (!LogTrace(reader_data, reader_len, reader_StartTime, reader_EndTime, reader_Parity, TRUE))
1790                 return FALSE;
1791         else
1792                 return(!LogTrace(tag_data, tag_len, tag_StartTime, tag_EndTime, tag_Parity, FALSE));
1793
1794 }
1795
1796 //-----------------------------------------------------------------------------
1797 // Wait a certain time for tag response
1798 //  If a response is captured return TRUE
1799 //  If it takes too long return FALSE
1800 //-----------------------------------------------------------------------------
1801 static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receivedResponsePar, uint16_t offset)
1802 {
1803         uint32_t c = 0x00;
1804
1805         // Set FPGA mode to "reader listen mode", no modulation (listen
1806         // only, since we are receiving, not transmitting).
1807         // Signal field is on with the appropriate LED
1808         LED_D_ON();
1809         FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
1810
1811         // Now get the answer from the card
1812         DemodInit(receivedResponse, receivedResponsePar);
1813
1814         // clear RXRDY:
1815     uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1816
1817         for(;;) {
1818                 WDT_HIT();
1819
1820                 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1821                         b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1822                         if(ManchesterDecoding(b, offset, 0)) {
1823                                 NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD);
1824                                 return TRUE;
1825                         } else if (c++ > iso14a_timeout && Demod.state == DEMOD_UNSYNCD) {
1826                                 return FALSE;
1827                         }
1828                 }
1829         }
1830 }
1831
1832 void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t *timing)
1833 {
1834         CodeIso14443aBitsAsReaderPar(frame, bits, par);
1835
1836         // Send command to tag
1837         TransmitFor14443a(ToSend, ToSendMax, timing);
1838         if(trigger)
1839                 LED_A_ON();
1840
1841         // Log reader command in trace buffer
1842         //LogTrace(frame, nbytes(bits), LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_READER, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_READER, par, TRUE);
1843         LogTrace(frame, nbytes(bits), (LastTimeProxToAirStart<<4) + DELAY_ARM2AIR_AS_READER, ((LastTimeProxToAirStart + LastProxToAirDuration)<<4) + DELAY_ARM2AIR_AS_READER, par, TRUE);
1844 }
1845
1846 void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *timing)
1847 {
1848   //ReaderTransmitBitsPar(frame, len*8, par, timing);
1849   ReaderTransmitBitsPar(frame, len<<3, par, timing);
1850 }
1851
1852 void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing)
1853 {
1854   // Generate parity and redirect
1855   uint8_t par[MAX_PARITY_SIZE] = {0x00};
1856   //GetParity(frame, len/8, par);
1857   GetParity(frame, len >> 3, par);
1858   ReaderTransmitBitsPar(frame, len, par, timing);
1859 }
1860
1861 void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *timing)
1862 {
1863   // Generate parity and redirect
1864   uint8_t par[MAX_PARITY_SIZE] = {0x00};
1865   GetParity(frame, len, par);
1866   //ReaderTransmitBitsPar(frame, len*8, par, timing);
1867   ReaderTransmitBitsPar(frame, len<<3, par, timing);
1868 }
1869
1870 int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset, uint8_t *parity)
1871 {
1872         if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, offset))
1873                 return FALSE;
1874
1875         //LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1876         LogTrace(receivedAnswer, Demod.len, (Demod.startTime<<4) - DELAY_AIR2ARM_AS_READER, (Demod.endTime<<4) - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1877         return Demod.len;
1878 }
1879
1880 int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity)
1881 {
1882         if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, 0))
1883                 return FALSE;
1884
1885         //LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1886         LogTrace(receivedAnswer, Demod.len, (Demod.startTime<<4) - DELAY_AIR2ARM_AS_READER, (Demod.endTime<<4) - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1887         return Demod.len;
1888 }
1889
1890 // performs iso14443a anticollision (optional) and card select procedure
1891 // fills the uid and cuid pointer unless NULL
1892 // fills the card info record unless NULL
1893 // if anticollision is false, then the UID must be provided in uid_ptr[]
1894 // and num_cascades must be set (1: 4 Byte UID, 2: 7 Byte UID, 3: 10 Byte UID)
1895 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) {
1896         uint8_t wupa[]       = { 0x52 };  // 0x26 - REQA  0x52 - WAKE-UP
1897         uint8_t sel_all[]    = { 0x93,0x20 };
1898         uint8_t sel_uid[]    = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
1899         uint8_t rats[]       = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
1900         uint8_t resp[MAX_FRAME_SIZE] = {0}; // theoretically. A usual RATS will be much smaller
1901         uint8_t resp_par[MAX_PARITY_SIZE] = {0};
1902         byte_t uid_resp[4] = {0};
1903         size_t uid_resp_len = 0;
1904
1905         uint8_t sak = 0x04; // cascade uid
1906         int cascade_level = 0;
1907         int len;
1908
1909         // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
1910     ReaderTransmitBitsPar(wupa, 7, NULL, NULL);
1911
1912         // Receive the ATQA
1913         if(!ReaderReceive(resp, resp_par)) return 0;
1914
1915         if(p_hi14a_card) {
1916                 memcpy(p_hi14a_card->atqa, resp, 2);
1917                 p_hi14a_card->uidlen = 0;
1918                 memset(p_hi14a_card->uid,0,10);
1919         }
1920
1921         if (anticollision) {
1922                 // clear uid
1923                 if (uid_ptr)
1924                         memset(uid_ptr,0,10);
1925         }
1926
1927         // check for proprietary anticollision:
1928         if ((resp[0] & 0x1F) == 0) return 3;
1929
1930         // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
1931         // which case we need to make a cascade 2 request and select - this is a long UID
1932         // While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
1933         for(; sak & 0x04; cascade_level++) {
1934                 // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
1935                 sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
1936
1937                 if (anticollision) {
1938                 // SELECT_ALL
1939                         ReaderTransmit(sel_all, sizeof(sel_all), NULL);
1940                         if (!ReaderReceive(resp, resp_par)) return 0;
1941
1942                         if (Demod.collisionPos) {                       // we had a collision and need to construct the UID bit by bit
1943                                 memset(uid_resp, 0, 4);
1944                                 uint16_t uid_resp_bits = 0;
1945                                 uint16_t collision_answer_offset = 0;
1946                                 // anti-collision-loop:
1947                                 while (Demod.collisionPos) {
1948                                         Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos);
1949                                         for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) {      // add valid UID bits before collision point
1950                                                 uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01;
1951                                                 uid_resp[uid_resp_bits / 8] |= UIDbit << (uid_resp_bits % 8);
1952                                         }
1953                                         uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8);                                  // next time select the card(s) with a 1 in the collision position
1954                                         uid_resp_bits++;
1955                                         // construct anticollosion command:
1956                                         sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07);     // length of data in bytes and bits
1957                                         for (uint16_t i = 0; i <= uid_resp_bits/8; i++) {
1958                                                 sel_uid[2+i] = uid_resp[i];
1959                                         }
1960                                         collision_answer_offset = uid_resp_bits%8;
1961                                         ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL);
1962                                         if (!ReaderReceiveOffset(resp, collision_answer_offset, resp_par)) return 0;
1963                                 }
1964                                 // finally, add the last bits and BCC of the UID
1965                                 for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) {
1966                                         uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01;
1967                                         uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8);
1968                                 }
1969
1970                         } else {                // no collision, use the response to SELECT_ALL as current uid
1971                                 memcpy(uid_resp, resp, 4);
1972                         }
1973
1974                 } else {
1975                         if (cascade_level < num_cascades - 1) {
1976                                 uid_resp[0] = 0x88;
1977                                 memcpy(uid_resp+1, uid_ptr+cascade_level*3, 3);
1978                         } else {
1979                                 memcpy(uid_resp, uid_ptr+cascade_level*3, 4);
1980                         }
1981                 }
1982                 uid_resp_len = 4;
1983
1984                 // calculate crypto UID. Always use last 4 Bytes.
1985                 if(cuid_ptr)
1986                         *cuid_ptr = bytes_to_num(uid_resp, 4);
1987
1988                 // Construct SELECT UID command
1989                 sel_uid[1] = 0x70;                                                                                                      // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC)
1990                 memcpy(sel_uid+2, uid_resp, 4);                                                                         // the UID received during anticollision, or the provided UID
1991                 sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5];         // calculate and add BCC
1992                 AppendCrc14443a(sel_uid, 7);                                                                            // calculate and add CRC
1993                 ReaderTransmit(sel_uid, sizeof(sel_uid), NULL);
1994
1995                 // Receive the SAK
1996                 if (!ReaderReceive(resp, resp_par)) return 0;
1997
1998                 sak = resp[0];
1999
2000                 // Test if more parts of the uid are coming
2001                 if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) {
2002                         // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of:
2003                         // http://www.nxp.com/documents/application_note/AN10927.pdf
2004                         uid_resp[0] = uid_resp[1];
2005                         uid_resp[1] = uid_resp[2];
2006                         uid_resp[2] = uid_resp[3];
2007                         uid_resp_len = 3;
2008                 }
2009
2010                 if(uid_ptr && anticollision)
2011                         memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len);
2012
2013                 if(p_hi14a_card) {
2014                         memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
2015                         p_hi14a_card->uidlen += uid_resp_len;
2016                 }
2017         }
2018
2019         if(p_hi14a_card) {
2020                 p_hi14a_card->sak = sak;
2021                 p_hi14a_card->ats_len = 0;
2022         }
2023
2024         // non iso14443a compliant tag
2025         if( (sak & 0x20) == 0) return 2;
2026
2027         // Request for answer to select
2028         AppendCrc14443a(rats, 2);
2029         ReaderTransmit(rats, sizeof(rats), NULL);
2030
2031         if (!(len = ReaderReceive(resp, resp_par))) return 0;
2032
2033         if(p_hi14a_card) {
2034                 memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
2035                 p_hi14a_card->ats_len = len;
2036         }
2037
2038         // reset the PCB block number
2039         iso14_pcb_blocknum = 0;
2040
2041         // set default timeout based on ATS
2042         iso14a_set_ATS_timeout(resp);
2043
2044         return 1;
2045 }
2046
2047 void iso14443a_setup(uint8_t fpga_minor_mode) {
2048         FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
2049         // Set up the synchronous serial port
2050         FpgaSetupSsc();
2051         // connect Demodulated Signal to ADC:
2052         SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
2053
2054         // Signal field is on with the appropriate LED
2055         if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD
2056                 || fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN) {
2057                 LED_D_ON();
2058         } else {
2059                 LED_D_OFF();
2060         }
2061         FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode);
2062
2063         // Start the timer
2064         StartCountSspClk();
2065
2066         DemodReset();
2067         UartReset();
2068         NextTransferTime = 2*DELAY_ARM2AIR_AS_READER;
2069         iso14a_set_timeout(10*106); // 10ms default
2070 }
2071
2072 int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data) {
2073         uint8_t parity[MAX_PARITY_SIZE] = {0x00};
2074         uint8_t real_cmd[cmd_len+4];
2075         real_cmd[0] = 0x0a; //I-Block
2076         // put block number into the PCB
2077         real_cmd[0] |= iso14_pcb_blocknum;
2078         real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards
2079         memcpy(real_cmd+2, cmd, cmd_len);
2080         AppendCrc14443a(real_cmd,cmd_len+2);
2081
2082         ReaderTransmit(real_cmd, cmd_len+4, NULL);
2083         size_t len = ReaderReceive(data, parity);
2084         uint8_t *data_bytes = (uint8_t *) data;
2085         if (!len)
2086                 return 0; //DATA LINK ERROR
2087         // if we received an I- or R(ACK)-Block with a block number equal to the
2088         // current block number, toggle the current block number
2089         else if (len >= 4 // PCB+CID+CRC = 4 bytes
2090                  && ((data_bytes[0] & 0xC0) == 0 // I-Block
2091                      || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0
2092                  && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers
2093         {
2094                 iso14_pcb_blocknum ^= 1;
2095         }
2096
2097         return len;
2098 }
2099
2100 //-----------------------------------------------------------------------------
2101 // Read an ISO 14443a tag. Send out commands and store answers.
2102 //
2103 //-----------------------------------------------------------------------------
2104 void ReaderIso14443a(UsbCommand *c)
2105 {
2106         iso14a_command_t param = c->arg[0];
2107         uint8_t *cmd = c->d.asBytes;
2108         size_t len = c->arg[1] & 0xffff;
2109         size_t lenbits = c->arg[1] >> 16;
2110         uint32_t timeout = c->arg[2];
2111         uint32_t arg0 = 0;
2112         byte_t buf[USB_CMD_DATA_SIZE] = {0x00};
2113         uint8_t par[MAX_PARITY_SIZE] = {0x00};
2114
2115         if (param & ISO14A_CONNECT)
2116                 clear_trace();
2117
2118         set_tracing(TRUE);
2119
2120         if (param & ISO14A_REQUEST_TRIGGER)
2121                 iso14a_set_trigger(TRUE);
2122
2123
2124         if (param & ISO14A_CONNECT) {
2125                 iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN);
2126                 if(!(param & ISO14A_NO_SELECT)) {
2127                         iso14a_card_select_t *card = (iso14a_card_select_t*)buf;
2128                         arg0 = iso14443a_select_card(NULL,card,NULL, true, 0);
2129                         cmd_send(CMD_ACK,arg0,card->uidlen,0,buf,sizeof(iso14a_card_select_t));
2130                 }
2131         }
2132
2133         if (param & ISO14A_SET_TIMEOUT)
2134                 iso14a_set_timeout(timeout);
2135
2136         if (param & ISO14A_APDU) {
2137                 arg0 = iso14_apdu(cmd, len, buf);
2138                 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
2139         }
2140
2141         if (param & ISO14A_RAW) {
2142                 if(param & ISO14A_APPEND_CRC) {
2143                         if(param & ISO14A_TOPAZMODE) {
2144                                 AppendCrc14443b(cmd,len);
2145                         } else {
2146                                 AppendCrc14443a(cmd,len);
2147                         }
2148                         len += 2;
2149                         if (lenbits) lenbits += 16;
2150                 }
2151                 if(lenbits>0) {                         // want to send a specific number of bits (e.g. short commands)
2152                         if(param & ISO14A_TOPAZMODE) {
2153                                 int bits_to_send = lenbits;
2154                                 uint16_t i = 0;
2155                                 ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 7), NULL, NULL);             // first byte is always short (7bits) and no parity
2156                                 bits_to_send -= 7;
2157                                 while (bits_to_send > 0) {
2158                                         ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 8), NULL, NULL);     // following bytes are 8 bit and no parity
2159                                         bits_to_send -= 8;
2160                                 }
2161                         } else {
2162                         GetParity(cmd, lenbits/8, par);
2163                                 ReaderTransmitBitsPar(cmd, lenbits, par, NULL);                                                 // bytes are 8 bit with odd parity
2164                         }
2165                 } else {                                        // want to send complete bytes only
2166                         if(param & ISO14A_TOPAZMODE) {
2167                                 uint16_t i = 0;
2168                                 ReaderTransmitBitsPar(&cmd[i++], 7, NULL, NULL);                                                // first byte: 7 bits, no paritiy
2169                                 while (i < len) {
2170                                         ReaderTransmitBitsPar(&cmd[i++], 8, NULL, NULL);                                        // following bytes: 8 bits, no paritiy
2171                                 }
2172                 } else {
2173                                 ReaderTransmit(cmd,len, NULL);                                                                                  // 8 bits, odd parity
2174                         }
2175                 }
2176                 arg0 = ReaderReceive(buf, par);
2177                 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
2178         }
2179
2180         if (param & ISO14A_REQUEST_TRIGGER)
2181                 iso14a_set_trigger(FALSE);
2182
2183
2184         if (param & ISO14A_NO_DISCONNECT)
2185                 return;
2186
2187         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2188         set_tracing(FALSE);
2189         LEDsoff();
2190 }
2191
2192
2193 // Determine the distance between two nonces.
2194 // Assume that the difference is small, but we don't know which is first.
2195 // Therefore try in alternating directions.
2196 int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
2197
2198         if (nt1 == nt2) return 0;
2199
2200         uint32_t nttmp1 = nt1;
2201         uint32_t nttmp2 = nt2;
2202
2203         for (uint16_t i = 1; i < 0xFFFF; i += 8) {
2204                 nttmp1 = prng_successor(nttmp1, 1);     if (nttmp1 == nt2) return i;
2205                 nttmp2 = prng_successor(nttmp2, 1);     if (nttmp2 == nt1) return -i;
2206
2207                 nttmp1 = prng_successor(nttmp1, 2);     if (nttmp1 == nt2) return i+1;
2208                 nttmp2 = prng_successor(nttmp2, 2);     if (nttmp2 == nt1) return -i-1;
2209
2210                 nttmp1 = prng_successor(nttmp1, 3);     if (nttmp1 == nt2) return i+2;
2211                 nttmp2 = prng_successor(nttmp2, 3);     if (nttmp2 == nt1) return -i-2;
2212
2213                 nttmp1 = prng_successor(nttmp1, 4);     if (nttmp1 == nt2) return i+3;
2214                 nttmp2 = prng_successor(nttmp2, 4);     if (nttmp2 == nt1) return -i-3;
2215
2216                 nttmp1 = prng_successor(nttmp1, 5);     if (nttmp1 == nt2) return i+4;
2217                 nttmp2 = prng_successor(nttmp2, 5);     if (nttmp2 == nt1) return -i-4;
2218
2219                 nttmp1 = prng_successor(nttmp1, 6);     if (nttmp1 == nt2) return i+5;
2220                 nttmp2 = prng_successor(nttmp2, 6);     if (nttmp2 == nt1) return -i-5;
2221
2222                 nttmp1 = prng_successor(nttmp1, 7);     if (nttmp1 == nt2) return i+6;
2223                 nttmp2 = prng_successor(nttmp2, 7);     if (nttmp2 == nt1) return -i-6;
2224
2225                 nttmp1 = prng_successor(nttmp1, 8);     if (nttmp1 == nt2) return i+7;
2226                 nttmp2 = prng_successor(nttmp2, 8);     if (nttmp2 == nt1) return -i-7;
2227         }
2228
2229         return(-99999); // either nt1 or nt2 are invalid nonces
2230 }
2231
2232
2233 //-----------------------------------------------------------------------------
2234 // Recover several bits of the cypher stream. This implements (first stages of)
2235 // the algorithm described in "The Dark Side of Security by Obscurity and
2236 // Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime"
2237 // (article by Nicolas T. Courtois, 2009)
2238 //-----------------------------------------------------------------------------
2239 void ReaderMifare(bool first_try, uint8_t block )
2240 {
2241         // Mifare AUTH
2242         //uint8_t mf_auth[]    = { 0x60,0x00,0xf5,0x7b };
2243         //uint8_t mf_auth[]    = { 0x60,0x05, 0x58, 0x2c };
2244         uint8_t mf_auth[]    = { 0x60,0x00, 0x00, 0x00 };
2245         uint8_t mf_nr_ar[]   = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
2246         static uint8_t mf_nr_ar3 = 0;
2247
2248         mf_auth[1] = block;
2249         AppendCrc14443a(mf_auth, 2);
2250
2251         uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE] = {0x00};
2252         uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE] = {0x00};
2253
2254         byte_t nt_diff = 0;
2255         uint8_t par[1] = {0};   // maximum 8 Bytes to be sent here, 1 byte parity is therefore enough
2256         static byte_t par_low = 0;
2257         uint8_t uid[10] = {0};
2258         //uint32_t cuid = 0;
2259
2260         uint32_t nt = 0;
2261         uint32_t previous_nt = 0;
2262         static uint32_t nt_attacked = 0;
2263         byte_t par_list[8] = {0x00};
2264         byte_t ks_list[8] = {0x00};
2265
2266         static uint32_t sync_time = 0;
2267         static int32_t sync_cycles = 0;
2268         int catch_up_cycles = 0;
2269         int last_catch_up = 0;
2270         uint16_t elapsed_prng_sequences = 1;
2271         uint16_t consecutive_resyncs = 0;
2272         int isOK = 0;
2273
2274         #define PRNG_SEQUENCE_LENGTH  (1 << 16);
2275         #define MAX_UNEXPECTED_RANDOM   4               // maximum number of unexpected (i.e. real) random numbers when trying to sync. Then give up.
2276         #define MAX_SYNC_TRIES                  32
2277         #define NUM_DEBUG_INFOS                 8               // per strategy
2278         #define MAX_STRATEGY                    3
2279
2280         uint16_t unexpected_random = 0;
2281         uint16_t sync_tries = 0;
2282         uint16_t strategy = 0;
2283         uint32_t halt_time = 0;
2284
2285         clear_trace();
2286         set_tracing(TRUE);
2287
2288         LED_A_ON();
2289         LED_B_OFF();
2290         LED_C_OFF();
2291
2292         if (first_try)
2293                 iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
2294
2295         // free eventually allocated BigBuf memory. We want all for tracing.
2296         BigBuf_free();
2297
2298         if (first_try) {
2299                 sync_time = GetCountSspClk() & 0xfffffff8;
2300                 sync_cycles = PRNG_SEQUENCE_LENGTH; //65536;    //0x10000                       // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
2301                 mf_nr_ar3 = 0;
2302                 nt_attacked = 0;
2303                 par[0] = 0;
2304         } else {
2305                 // we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same)
2306                 mf_nr_ar3++;
2307                 mf_nr_ar[3] = mf_nr_ar3;
2308                 par[0] = par_low;
2309         }
2310
2311         LED_C_ON();
2312         for(uint16_t i = 0; TRUE; ++i) {
2313
2314                 WDT_HIT();
2315
2316                 // Test if the action was cancelled
2317                 if(BUTTON_PRESS()) {
2318                         isOK = -1;
2319                         break;
2320                 }
2321
2322                 if (strategy == 2) {
2323                         // test with additional halt command
2324                         halt_time = 0;
2325                         int len = mifare_sendcmd_short(NULL, false, 0x50, 0x00, receivedAnswer, receivedAnswerPar, &halt_time);
2326
2327                         if (len && MF_DBGLEVEL >= 3)
2328                                 Dbprintf("Unexpected response of %d bytes to halt command.", len);
2329                 }
2330
2331                 if (strategy == 3) {
2332                         // test with FPGA power off/on
2333                         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2334                         SpinDelay(200);
2335                         iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
2336                         SpinDelay(100);
2337                         sync_time = GetCountSspClk() & 0xfffffff8;
2338                         WDT_HIT();
2339                 }
2340
2341                 if (!iso14443a_select_card(uid, NULL, NULL, true, 0)) {
2342                         if (MF_DBGLEVEL >= 1) Dbprintf("Mifare: Can't select card\n");
2343                         continue;
2344                 }
2345
2346                 sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
2347                 catch_up_cycles = 0;
2348
2349                 // if we missed the sync time already, advance to the next nonce repeat
2350                 while(GetCountSspClk() > sync_time) {
2351                         ++elapsed_prng_sequences;
2352                         sync_time = (sync_time & 0xfffffff8) + sync_cycles;
2353                 }
2354                 // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked)
2355                 ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
2356
2357                 // Receive the (4 Byte) "random" nonce
2358                 if (!ReaderReceive(receivedAnswer, receivedAnswerPar))
2359                         continue;
2360
2361                 // Transmit reader nonce with fake par
2362                 ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
2363
2364                 previous_nt = nt;
2365                 nt = bytes_to_num(receivedAnswer, 4);
2366
2367                 if (first_try && previous_nt && !nt_attacked) { // we didn't calibrate our clock yet
2368                         int nt_distance = dist_nt(previous_nt, nt);
2369                         if (nt_distance == 0) {
2370                                 nt_attacked = nt;
2371                         } else {
2372                                 if (nt_distance == -99999) { // invalid nonce received
2373                                         unexpected_random++;
2374                                         if (unexpected_random > MAX_UNEXPECTED_RANDOM) {
2375                                                 isOK = -3;              // Card has an unpredictable PRNG. Give up
2376                                                 break;
2377                                         } else {
2378                                                 continue;               // continue trying...
2379                                         }
2380                                 }
2381
2382                                 if (++sync_tries > MAX_SYNC_TRIES) {
2383                                         if (strategy > MAX_STRATEGY || MF_DBGLEVEL < 3) {
2384                                                 isOK = -4;                      // Card's PRNG runs at an unexpected frequency or resets unexpectedly
2385                                                 break;
2386                                         } else {
2387                                                 continue;
2388                                         }
2389                                 }
2390
2391                                 sync_cycles = (sync_cycles - nt_distance)/elapsed_prng_sequences;
2392                                 if (sync_cycles <= 0)
2393                                         sync_cycles += PRNG_SEQUENCE_LENGTH;
2394
2395                                 if (MF_DBGLEVEL >= 3)
2396                                         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);
2397
2398                                 continue;
2399                         }
2400                 }
2401
2402                 if ((nt != nt_attacked) && nt_attacked) {       // we somehow lost sync. Try to catch up again...
2403
2404                         catch_up_cycles = -dist_nt(nt_attacked, nt);
2405                         if (catch_up_cycles == 99999) {                 // invalid nonce received. Don't resync on that one.
2406                                 catch_up_cycles = 0;
2407                                 continue;
2408                         }
2409
2410                         // average?
2411                         catch_up_cycles /= elapsed_prng_sequences;
2412
2413                         if (catch_up_cycles == last_catch_up) {
2414                                 ++consecutive_resyncs;
2415                         } else {
2416                                 last_catch_up = catch_up_cycles;
2417                             consecutive_resyncs = 0;
2418                         }
2419
2420                         if (consecutive_resyncs < 3) {
2421                                 if (MF_DBGLEVEL >= 3)
2422                                         Dbprintf("Lost sync in cycle %d. nt_distance=%d. Consecutive Resyncs = %d. Trying one time catch up...\n", i, -catch_up_cycles, consecutive_resyncs);
2423                         } else {
2424                                 sync_cycles += catch_up_cycles;
2425
2426                                 if (MF_DBGLEVEL >= 3)
2427                                         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);
2428
2429                                 last_catch_up = 0;
2430                                 catch_up_cycles = 0;
2431                                 consecutive_resyncs = 0;
2432                         }
2433                         continue;
2434                 }
2435
2436                 // Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
2437                 if (ReaderReceive(receivedAnswer, receivedAnswerPar)) {
2438                         catch_up_cycles = 8;    // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
2439
2440                         if (nt_diff == 0)
2441                                 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
2442
2443                         par_list[nt_diff] = SwapBits(par[0], 8);
2444                         ks_list[nt_diff] = receivedAnswer[0] ^ 0x05;
2445
2446                         // Test if the information is complete
2447                         if (nt_diff == 0x07) {
2448                                 isOK = 1;
2449                                 break;
2450                         }
2451
2452                         nt_diff = (nt_diff + 1) & 0x07;
2453                         mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
2454                         par[0] = par_low;
2455
2456                 } else {
2457                         if (nt_diff == 0 && first_try) {
2458                                 par[0]++;
2459                                 if (par[0] == 0x00) {   // tried all 256 possible parities without success. Card doesn't send NACK.
2460                                         isOK = -2;
2461                                         break;
2462                                 }
2463                         } else {
2464                                 par[0] = ((par[0] & 0x1F) + 1) | par_low;
2465                         }
2466                 }
2467
2468                 consecutive_resyncs = 0;
2469         }
2470
2471         mf_nr_ar[3] &= 0x1F;
2472
2473         WDT_HIT();
2474
2475         // reset sync_time.
2476         if ( isOK == 1) {
2477                 sync_time =     0;
2478                 sync_cycles = 0;
2479                 mf_nr_ar3 = 0;
2480                 nt_attacked = 0;
2481                 par[0] = 0;
2482         }
2483
2484         byte_t buf[28] = {0x00};
2485         memcpy(buf + 0,  uid, 4);
2486         num_to_bytes(nt, 4, buf + 4);
2487         memcpy(buf + 8,  par_list, 8);
2488         memcpy(buf + 16, ks_list, 8);
2489         memcpy(buf + 24, mf_nr_ar, 4);
2490
2491         cmd_send(CMD_ACK,isOK,0,0,buf,28);
2492
2493         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2494         LEDsoff();
2495         set_tracing(FALSE);
2496 }
2497
2498 /**
2499   *MIFARE 1K simulate.
2500   *
2501   *@param flags :
2502   *     FLAG_INTERACTIVE - In interactive mode, we are expected to finish the operation with an ACK
2503   * 4B_FLAG_UID_IN_DATA - means that there is a 4-byte UID in the data-section, we're expected to use that
2504   * 7B_FLAG_UID_IN_DATA - means that there is a 7-byte UID in the data-section, we're expected to use that
2505   *     FLAG_NR_AR_ATTACK  - means we should collect NR_AR responses for bruteforcing later
2506   *@param exitAfterNReads, exit simulation after n blocks have been read, 0 is inifite
2507   */
2508 void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *datain)
2509 {
2510         int cardSTATE = MFEMUL_NOFIELD;
2511         int _7BUID = 0;
2512         int vHf = 0;    // in mV
2513         int res;
2514         uint32_t selTimer = 0;
2515         uint32_t authTimer = 0;
2516         uint16_t len = 0;
2517         uint8_t cardWRBL = 0;
2518         uint8_t cardAUTHSC = 0;
2519         uint8_t cardAUTHKEY = 0xff;  // no authentication
2520 //      uint32_t cardRr = 0;
2521         uint32_t cuid = 0;
2522         //uint32_t rn_enc = 0;
2523         uint32_t ans = 0;
2524         uint32_t cardINTREG = 0;
2525         uint8_t cardINTBLOCK = 0;
2526         struct Crypto1State mpcs = {0, 0};
2527         struct Crypto1State *pcs;
2528         pcs = &mpcs;
2529         uint32_t numReads = 0;//Counts numer of times reader read a block
2530         uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE] = {0x00};
2531         uint8_t receivedCmd_par[MAX_MIFARE_PARITY_SIZE] = {0x00};
2532         uint8_t response[MAX_MIFARE_FRAME_SIZE] = {0x00};
2533         uint8_t response_par[MAX_MIFARE_PARITY_SIZE] = {0x00};
2534
2535         uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID
2536         uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2537         uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; // !!!
2538         uint8_t rSAK[] = {0x08, 0xb6, 0xdd}; // Mifare Classic
2539         //uint8_t rSAK[] = {0x09, 0x3f, 0xcc };  // Mifare Mini
2540         uint8_t rSAK1[] = {0x04, 0xda, 0x17};
2541
2542         //uint8_t rAUTH_NT[] = {0x01, 0x01, 0x01, 0x01};
2543         uint8_t rAUTH_NT[] = {0x55, 0x41, 0x49, 0x92};
2544         uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
2545
2546         //Here, we collect UID1,UID2,NT,AR,NR,0,0,NT2,AR2,NR2
2547         // This can be used in a reader-only attack.
2548         // (it can also be retrieved via 'hf 14a list', but hey...
2549         uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0,0,0};
2550         uint8_t ar_nr_collected = 0;
2551
2552         // Authenticate response - nonce
2553         uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
2554
2555         //-- Determine the UID
2556         // Can be set from emulator memory, incoming data
2557         // and can be 7 or 4 bytes long
2558         if (flags & FLAG_4B_UID_IN_DATA)
2559         {
2560                 // 4B uid comes from data-portion of packet
2561                 memcpy(rUIDBCC1,datain,4);
2562                 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2563
2564         } else if (flags & FLAG_7B_UID_IN_DATA) {
2565                 // 7B uid comes from data-portion of packet
2566                 memcpy(&rUIDBCC1[1],datain,3);
2567                 memcpy(rUIDBCC2, datain+3, 4);
2568                 _7BUID = true;
2569         } else {
2570                 // get UID from emul memory
2571                 emlGetMemBt(receivedCmd, 7, 1);
2572                 _7BUID = !(receivedCmd[0] == 0x00);
2573                 if (!_7BUID) {                     // ---------- 4BUID
2574                         emlGetMemBt(rUIDBCC1, 0, 4);
2575                 } else {                           // ---------- 7BUID
2576                         emlGetMemBt(&rUIDBCC1[1], 0, 3);
2577                         emlGetMemBt(rUIDBCC2, 3, 4);
2578                 }
2579         }
2580
2581         // save uid.
2582         ar_nr_responses[0*5]   = bytes_to_num(rUIDBCC1+1, 3);
2583         if ( _7BUID )
2584                 ar_nr_responses[0*5+1] = bytes_to_num(rUIDBCC2, 4);
2585
2586         /*
2587          * Regardless of what method was used to set the UID, set fifth byte and modify
2588          * the ATQA for 4 or 7-byte UID
2589          */
2590         rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2591         if (_7BUID) {
2592                 rATQA[0] = 0x44;
2593                 rUIDBCC1[0] = 0x88;
2594                 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2595                 rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
2596         }
2597
2598         if (MF_DBGLEVEL >= 1)   {
2599                 if (!_7BUID) {
2600                         Dbprintf("4B UID: %02x%02x%02x%02x",
2601                                 rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3]);
2602                 } else {
2603                         Dbprintf("7B UID: (%02x)%02x%02x%02x%02x%02x%02x%02x",
2604                                 rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3],
2605                                 rUIDBCC2[0], rUIDBCC2[1] ,rUIDBCC2[2], rUIDBCC2[3]);
2606                 }
2607         }
2608
2609         // We need to listen to the high-frequency, peak-detected path.
2610         iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
2611
2612         // free eventually allocated BigBuf memory but keep Emulator Memory
2613         BigBuf_free_keep_EM();
2614
2615         // clear trace
2616         clear_trace();
2617         set_tracing(TRUE);
2618
2619
2620         bool finished = FALSE;
2621         while (!BUTTON_PRESS() && !finished && !usb_poll_validate_length()) {
2622                 WDT_HIT();
2623
2624                 // find reader field
2625                 if (cardSTATE == MFEMUL_NOFIELD) {
2626                         vHf = (MAX_ADC_HF_VOLTAGE * AvgAdc(ADC_CHAN_HF)) >> 10;
2627                         if (vHf > MF_MINFIELDV) {
2628                                 cardSTATE_TO_IDLE();
2629                                 LED_A_ON();
2630                         }
2631                 }
2632                 if(cardSTATE == MFEMUL_NOFIELD) continue;
2633
2634                 //Now, get data
2635                 res = EmGetCmd(receivedCmd, &len, receivedCmd_par);
2636                 if (res == 2) { //Field is off!
2637                         cardSTATE = MFEMUL_NOFIELD;
2638                         LEDsoff();
2639                         continue;
2640                 } else if (res == 1) {
2641                         break;  //return value 1 means button press
2642                 }
2643
2644                 // REQ or WUP request in ANY state and WUP in HALTED state
2645                 if (len == 1 && ((receivedCmd[0] == 0x26 && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == 0x52)) {
2646                         selTimer = GetTickCount();
2647                         EmSendCmdEx(rATQA, sizeof(rATQA), (receivedCmd[0] == 0x52));
2648                         cardSTATE = MFEMUL_SELECT1;
2649
2650                         // init crypto block
2651                         LED_B_OFF();
2652                         LED_C_OFF();
2653                         crypto1_destroy(pcs);
2654                         cardAUTHKEY = 0xff;
2655                         continue;
2656                 }
2657
2658                 switch (cardSTATE) {
2659                         case MFEMUL_NOFIELD:
2660                         case MFEMUL_HALTED:
2661                         case MFEMUL_IDLE:{
2662                                 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2663                                 break;
2664                         }
2665                         case MFEMUL_SELECT1:{
2666                                 // select all
2667                                 if (len == 2 && (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x20)) {
2668                                         if (MF_DBGLEVEL >= 4)   Dbprintf("SELECT ALL received");
2669                                         EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1));
2670                                         break;
2671                                 }
2672
2673                                 if (MF_DBGLEVEL >= 4 && len == 9 && receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 )
2674                                 {
2675                                         Dbprintf("SELECT %02x%02x%02x%02x received",receivedCmd[2],receivedCmd[3],receivedCmd[4],receivedCmd[5]);
2676                                 }
2677                                 // select card
2678                                 if (len == 9 &&
2679                                                 (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
2680                                         EmSendCmd(_7BUID?rSAK1:rSAK, _7BUID?sizeof(rSAK1):sizeof(rSAK));
2681                                         cuid = bytes_to_num(rUIDBCC1, 4);
2682                                         if (!_7BUID) {
2683                                                 cardSTATE = MFEMUL_WORK;
2684                                                 LED_B_ON();
2685                                                 if (MF_DBGLEVEL >= 4)   Dbprintf("--> WORK. anticol1 time: %d", GetTickCount() - selTimer);
2686                                                 break;
2687                                         } else {
2688                                                 cardSTATE = MFEMUL_SELECT2;
2689                                         }
2690                                 }
2691                                 break;
2692                         }
2693                         case MFEMUL_AUTH1:{
2694                                 if( len != 8) {
2695                                         cardSTATE_TO_IDLE();
2696                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2697                                         break;
2698                                 }
2699
2700                                 uint32_t ar = bytes_to_num(receivedCmd, 4);
2701                                 uint32_t nr = bytes_to_num(&receivedCmd[4], 4);
2702
2703                                 //Collect AR/NR
2704                                 //if(ar_nr_collected < 2 && cardAUTHSC == 2){
2705                                 if(ar_nr_collected < 2) {
2706                                         if(ar_nr_responses[2] != ar) {
2707                                                 // Avoid duplicates... probably not necessary, ar should vary.
2708                                                 //ar_nr_responses[ar_nr_collected*5]   = 0;
2709                                                 //ar_nr_responses[ar_nr_collected*5+1] = 0;
2710                                                 ar_nr_responses[ar_nr_collected*5+2] = nonce;
2711                                                 ar_nr_responses[ar_nr_collected*5+3] = nr;
2712                                                 ar_nr_responses[ar_nr_collected*5+4] = ar;
2713                                                 ar_nr_collected++;
2714                                         }
2715                                         // Interactive mode flag, means we need to send ACK
2716                                         if(flags & FLAG_INTERACTIVE && ar_nr_collected == 2)
2717                                                 finished = true;
2718                                 }
2719
2720                                 // --- crypto
2721                                 //crypto1_word(pcs, ar , 1);
2722                                 //cardRr = nr ^ crypto1_word(pcs, 0, 0);
2723
2724                                 //test if auth OK
2725                                 //if (cardRr != prng_successor(nonce, 64)){
2726
2727                                         //if (MF_DBGLEVEL >= 4) Dbprintf("AUTH FAILED for sector %d with key %c. cardRr=%08x, succ=%08x",
2728                                         //      cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
2729                                         //              cardRr, prng_successor(nonce, 64));
2730                                         // Shouldn't we respond anything here?
2731                                         // Right now, we don't nack or anything, which causes the
2732                                         // reader to do a WUPA after a while. /Martin
2733                                         // -- which is the correct response. /piwi
2734                                         //cardSTATE_TO_IDLE();
2735                                         //LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2736                                         //break;
2737                                 //}
2738
2739                                 ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0);
2740
2741                                 num_to_bytes(ans, 4, rAUTH_AT);
2742                                 // --- crypto
2743                                 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2744                                 LED_C_ON();
2745                                 cardSTATE = MFEMUL_WORK;
2746                                 if (MF_DBGLEVEL >= 4) {
2747                                         Dbprintf("AUTH COMPLETED for sector %d with key %c. time=%d",
2748                                                 cardAUTHSC,
2749                                                 cardAUTHKEY == 0 ? 'A' : 'B',
2750                                                 GetTickCount() - authTimer
2751                                         );
2752                                 }
2753                                 break;
2754                         }
2755                         case MFEMUL_SELECT2:{
2756                                 if (!len) {
2757                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2758                                         break;
2759                                 }
2760                                 if (len == 2 && (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x20)) {
2761                                         EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2));
2762                                         break;
2763                                 }
2764
2765                                 // select 2 card
2766                                 if (len == 9 &&
2767                                                 (receivedCmd[0] == 0x95 &&
2768                                                  receivedCmd[1] == 0x70 &&
2769                                                  memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0) ) {
2770                                         EmSendCmd(rSAK, sizeof(rSAK));
2771                                         cuid = bytes_to_num(rUIDBCC2, 4);
2772                                         cardSTATE = MFEMUL_WORK;
2773                                         LED_B_ON();
2774                                         if (MF_DBGLEVEL >= 4)   Dbprintf("--> WORK. anticol2 time: %d", GetTickCount() - selTimer);
2775                                         break;
2776                                 }
2777
2778                                 // i guess there is a command). go into the work state.
2779                                 if (len != 4) {
2780                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2781                                         break;
2782                                 }
2783                                 cardSTATE = MFEMUL_WORK;
2784                                 //goto lbWORK;
2785                                 //intentional fall-through to the next case-stmt
2786                         }
2787
2788                         case MFEMUL_WORK:{
2789                                 if (len == 0) {
2790                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2791                                         break;
2792                                 }
2793
2794                                 bool encrypted_data = (cardAUTHKEY != 0xFF) ;
2795
2796                                 // decrypt seqence
2797                                 if(encrypted_data)
2798                                         mf_crypto1_decrypt(pcs, receivedCmd, len);
2799
2800                                 if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) {
2801                                         authTimer = GetTickCount();
2802                                         cardAUTHSC = receivedCmd[1] / 4;  // received block num
2803                                         cardAUTHKEY = receivedCmd[0] - 0x60;
2804                                         crypto1_destroy(pcs);//Added by martin
2805                                         crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
2806
2807                                         if (!encrypted_data) { // first authentication
2808                                                 if (MF_DBGLEVEL >= 4) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY  );
2809
2810                                                 crypto1_word(pcs, cuid ^ nonce, 0);//Update crypto state
2811                                                 num_to_bytes(nonce, 4, rAUTH_AT); // Send nonce
2812                                         } else { // nested authentication
2813                                                 if (MF_DBGLEVEL >= 4) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2814                                                 ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0);
2815                                                 num_to_bytes(ans, 4, rAUTH_AT);
2816                                         }
2817
2818                                         EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2819                                         //Dbprintf("Sending rAUTH %02x%02x%02x%02x", rAUTH_AT[0],rAUTH_AT[1],rAUTH_AT[2],rAUTH_AT[3]);
2820                                         cardSTATE = MFEMUL_AUTH1;
2821                                         break;
2822                                 }
2823
2824                                 // rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued
2825                                 // BUT... ACK --> NACK
2826                                 if (len == 1 && receivedCmd[0] == CARD_ACK) {
2827                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2828                                         break;
2829                                 }
2830
2831                                 // rule 12 of 7.5.3. in ISO 14443-4. R(NAK) --> R(ACK)
2832                                 if (len == 1 && receivedCmd[0] == CARD_NACK_NA) {
2833                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2834                                         break;
2835                                 }
2836
2837                                 if(len != 4) {
2838                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2839                                         break;
2840                                 }
2841
2842                                 if(receivedCmd[0] == 0x30 // read block
2843                                                 || receivedCmd[0] == 0xA0 // write block
2844                                                 || receivedCmd[0] == 0xC0 // inc
2845                                                 || receivedCmd[0] == 0xC1 // dec
2846                                                 || receivedCmd[0] == 0xC2 // restore
2847                                                 || receivedCmd[0] == 0xB0) { // transfer
2848                                         if (receivedCmd[1] >= 16 * 4) {
2849                                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2850                                                 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]);
2851                                                 break;
2852                                         }
2853
2854                                         if (receivedCmd[1] / 4 != cardAUTHSC) {
2855                                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2856                                                 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);
2857                                                 break;
2858                                         }
2859                                 }
2860                                 // read block
2861                                 if (receivedCmd[0] == 0x30) {
2862                                         if (MF_DBGLEVEL >= 4) Dbprintf("Reader reading block %d (0x%02x)",receivedCmd[1],receivedCmd[1]);
2863
2864                                         emlGetMem(response, receivedCmd[1], 1);
2865                                         AppendCrc14443a(response, 16);
2866                                         mf_crypto1_encrypt(pcs, response, 18, response_par);
2867                                         EmSendCmdPar(response, 18, response_par);
2868                                         numReads++;
2869                                         if(exitAfterNReads > 0 && numReads >= exitAfterNReads) {
2870                                                 Dbprintf("%d reads done, exiting", numReads);
2871                                                 finished = true;
2872                                         }
2873                                         break;
2874                                 }
2875                                 // write block
2876                                 if (receivedCmd[0] == 0xA0) {
2877                                         if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0xA0 write block %d (%02x)",receivedCmd[1],receivedCmd[1]);
2878                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2879                                         cardSTATE = MFEMUL_WRITEBL2;
2880                                         cardWRBL = receivedCmd[1];
2881                                         break;
2882                                 }
2883                                 // increment, decrement, restore
2884                                 if (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2) {
2885                                         if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2886                                         if (emlCheckValBl(receivedCmd[1])) {
2887                                                 if (MF_DBGLEVEL >= 4) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking");
2888                                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2889                                                 break;
2890                                         }
2891                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2892                                         if (receivedCmd[0] == 0xC1)
2893                                                 cardSTATE = MFEMUL_INTREG_INC;
2894                                         if (receivedCmd[0] == 0xC0)
2895                                                 cardSTATE = MFEMUL_INTREG_DEC;
2896                                         if (receivedCmd[0] == 0xC2)
2897                                                 cardSTATE = MFEMUL_INTREG_REST;
2898                                         cardWRBL = receivedCmd[1];
2899                                         break;
2900                                 }
2901                                 // transfer
2902                                 if (receivedCmd[0] == 0xB0) {
2903                                         if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x transfer block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2904                                         if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
2905                                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2906                                         else
2907                                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2908                                         break;
2909                                 }
2910                                 // halt
2911                                 if (receivedCmd[0] == 0x50 && receivedCmd[1] == 0x00) {
2912                                         LED_B_OFF();
2913                                         LED_C_OFF();
2914                                         cardSTATE = MFEMUL_HALTED;
2915                                         if (MF_DBGLEVEL >= 4)   Dbprintf("--> HALTED. Selected time: %d ms",  GetTickCount() - selTimer);
2916                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2917                                         break;
2918                                 }
2919                                 // RATS
2920                                 if (receivedCmd[0] == 0xe0) {//RATS
2921                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2922                                         break;
2923                                 }
2924                                 // command not allowed
2925                                 if (MF_DBGLEVEL >= 4)   Dbprintf("Received command not allowed, nacking");
2926                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2927                                 break;
2928                         }
2929                         case MFEMUL_WRITEBL2:{
2930                                 if (len == 18) {
2931                                         mf_crypto1_decrypt(pcs, receivedCmd, len);
2932                                         emlSetMem(receivedCmd, cardWRBL, 1);
2933                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2934                                         cardSTATE = MFEMUL_WORK;
2935                                 } else {
2936                                         cardSTATE_TO_IDLE();
2937                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2938                                 }
2939                                 break;
2940                         }
2941
2942                         case MFEMUL_INTREG_INC:{
2943                                 mf_crypto1_decrypt(pcs, receivedCmd, len);
2944                                 memcpy(&ans, receivedCmd, 4);
2945                                 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2946                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2947                                         cardSTATE_TO_IDLE();
2948                                         break;
2949                                 }
2950                                 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2951                                 cardINTREG = cardINTREG + ans;
2952                                 cardSTATE = MFEMUL_WORK;
2953                                 break;
2954                         }
2955                         case MFEMUL_INTREG_DEC:{
2956                                 mf_crypto1_decrypt(pcs, receivedCmd, len);
2957                                 memcpy(&ans, receivedCmd, 4);
2958                                 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2959                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2960                                         cardSTATE_TO_IDLE();
2961                                         break;
2962                                 }
2963                                 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2964                                 cardINTREG = cardINTREG - ans;
2965                                 cardSTATE = MFEMUL_WORK;
2966                                 break;
2967                         }
2968                         case MFEMUL_INTREG_REST:{
2969                                 mf_crypto1_decrypt(pcs, receivedCmd, len);
2970                                 memcpy(&ans, receivedCmd, 4);
2971                                 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2972                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2973                                         cardSTATE_TO_IDLE();
2974                                         break;
2975                                 }
2976                                 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2977                                 cardSTATE = MFEMUL_WORK;
2978                                 break;
2979                         }
2980                 }
2981         }
2982
2983         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2984         LEDsoff();
2985
2986         // Interactive mode flag, means we need to send ACK
2987         if(flags & FLAG_INTERACTIVE) {
2988                 //May just aswell send the collected ar_nr in the response aswell
2989                 uint8_t len = ar_nr_collected*5*4;
2990                 cmd_send(CMD_ACK, CMD_SIMULATE_MIFARE_CARD, len, 0, &ar_nr_responses, len);
2991         }
2992
2993         if(flags & FLAG_NR_AR_ATTACK && MF_DBGLEVEL >= 1 ) {
2994                 if(ar_nr_collected > 1 ) {
2995                         Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
2996                         Dbprintf("../tools/mfkey/mfkey32 %06x%08x %08x %08x %08x %08x %08x",
2997                                         ar_nr_responses[0], // UID1
2998                                         ar_nr_responses[1], // UID2
2999                                         ar_nr_responses[2], // NT
3000                                         ar_nr_responses[3], // AR1
3001                                         ar_nr_responses[4], // NR1
3002                                         ar_nr_responses[8], // AR2
3003                                         ar_nr_responses[9]  // NR2
3004                                         );
3005                         Dbprintf("../tools/mfkey/mfkey32v2 %06x%08x %08x %08x %08x %08x %08x %08x",
3006                                         ar_nr_responses[0], // UID1
3007                                         ar_nr_responses[1], // UID2
3008                                         ar_nr_responses[2], // NT1
3009                                         ar_nr_responses[3], // AR1
3010                                         ar_nr_responses[4], // NR1
3011                                         ar_nr_responses[7], // NT2
3012                                         ar_nr_responses[8], // AR2
3013                                         ar_nr_responses[9]  // NR2
3014                                         );
3015                 } else {
3016                         Dbprintf("Failed to obtain two AR/NR pairs!");
3017                         if(ar_nr_collected > 0 ) {
3018                                 Dbprintf("Only got these: UID=%06x%08x, nonce=%08x, AR1=%08x, NR1=%08x",
3019                                                 ar_nr_responses[0], // UID1
3020                                                 ar_nr_responses[1], // UID2
3021                                                 ar_nr_responses[2], // NT
3022                                                 ar_nr_responses[3], // AR1
3023                                                 ar_nr_responses[4]  // NR1
3024                                                 );
3025                         }
3026                 }
3027         }
3028         if (MF_DBGLEVEL >= 1)   Dbprintf("Emulator stopped. Tracing: %d  trace length: %d ", tracing, BigBuf_get_traceLen());
3029
3030         set_tracing(FALSE);
3031 }
3032
3033
3034 //-----------------------------------------------------------------------------
3035 // MIFARE sniffer.
3036 //
3037 //-----------------------------------------------------------------------------
3038 void RAMFUNC SniffMifare(uint8_t param) {
3039         // param:
3040         // bit 0 - trigger from first card answer
3041         // bit 1 - trigger from first reader 7-bit request
3042         LEDsoff();
3043
3044         // init trace buffer
3045         clear_trace();
3046         set_tracing(TRUE);
3047
3048         // The command (reader -> tag) that we're receiving.
3049         // The length of a received command will in most cases be no more than 18 bytes.
3050         // So 32 should be enough!
3051         uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE] = {0x00};
3052         uint8_t receivedCmdPar[MAX_MIFARE_PARITY_SIZE] = {0x00};
3053
3054         // The response (tag -> reader) that we're receiving.
3055         uint8_t receivedResponse[MAX_MIFARE_FRAME_SIZE] = {0x00};
3056         uint8_t receivedResponsePar[MAX_MIFARE_PARITY_SIZE] = {0x00};
3057
3058         iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
3059
3060         // free eventually allocated BigBuf memory
3061         BigBuf_free();
3062
3063         // allocate the DMA buffer, used to stream samples from the FPGA
3064         uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
3065         uint8_t *data = dmaBuf;
3066         uint8_t previous_data = 0;
3067         int maxDataLen = 0;
3068         int dataLen = 0;
3069         bool ReaderIsActive = FALSE;
3070         bool TagIsActive = FALSE;
3071
3072         // Set up the demodulator for tag -> reader responses.
3073         DemodInit(receivedResponse, receivedResponsePar);
3074
3075         // Set up the demodulator for the reader -> tag commands
3076         UartInit(receivedCmd, receivedCmdPar);
3077
3078         // Setup for the DMA.
3079         FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
3080
3081         LED_D_OFF();
3082
3083         // init sniffer
3084         MfSniffInit();
3085
3086         // And now we loop, receiving samples.
3087         for(uint32_t sniffCounter = 0; TRUE; ) {
3088
3089                 if(BUTTON_PRESS()) {
3090                         DbpString("cancelled by button");
3091                         break;
3092                 }
3093
3094                 LED_A_ON();
3095                 WDT_HIT();
3096
3097                 if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time
3098                         // check if a transaction is completed (timeout after 2000ms).
3099                         // if yes, stop the DMA transfer and send what we have so far to the client
3100                         if (MfSniffSend(2000)) {
3101                                 // Reset everything - we missed some sniffed data anyway while the DMA was stopped
3102                                 sniffCounter = 0;
3103                                 data = dmaBuf;
3104                                 maxDataLen = 0;
3105                                 ReaderIsActive = FALSE;
3106                                 TagIsActive = FALSE;
3107                                 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
3108                         }
3109                 }
3110
3111                 int register readBufDataP = data - dmaBuf;      // number of bytes we have processed so far
3112                 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred
3113
3114                 if (readBufDataP <= dmaBufDataP)                        // we are processing the same block of data which is currently being transferred
3115                         dataLen = dmaBufDataP - readBufDataP;   // number of bytes still to be processed
3116                 else
3117                         dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed
3118
3119                 // test for length of buffer
3120                 if(dataLen > maxDataLen) {                                      // we are more behind than ever...
3121                         maxDataLen = dataLen;
3122                         if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
3123                                 Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
3124                                 break;
3125                         }
3126                 }
3127                 if(dataLen < 1) continue;
3128
3129                 // primary buffer was stopped ( <-- we lost data!
3130                 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
3131                         AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
3132                         AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
3133                         Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
3134                 }
3135                 // secondary buffer sets as primary, secondary buffer was stopped
3136                 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
3137                         AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
3138                         AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
3139                 }
3140
3141                 LED_A_OFF();
3142
3143                 if (sniffCounter & 0x01) {
3144
3145                         // no need to try decoding tag data if the reader is sending
3146                         if(!TagIsActive) {
3147                                 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
3148                                 if(MillerDecoding(readerdata, (sniffCounter-1)*4)) {
3149                                         LED_C_INV();
3150
3151                                         if (MfSniffLogic(receivedCmd, Uart.len, Uart.parity, Uart.bitCount, TRUE)) break;
3152
3153                                         /* And ready to receive another command. */
3154                                         UartInit(receivedCmd, receivedCmdPar);
3155
3156                                         /* And also reset the demod code */
3157                                         DemodReset();
3158                                 }
3159                                 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
3160                         }
3161
3162                         // no need to try decoding tag data if the reader is sending
3163                         if(!ReaderIsActive) {
3164                                 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
3165                                 if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) {
3166                                         LED_C_INV();
3167
3168                                         if (MfSniffLogic(receivedResponse, Demod.len, Demod.parity, Demod.bitCount, FALSE)) break;
3169
3170                                         // And ready to receive another response.
3171                                         DemodReset();
3172
3173                                         // And reset the Miller decoder including its (now outdated) input buffer
3174                                         UartInit(receivedCmd, receivedCmdPar);
3175                                 }
3176                                 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
3177                         }
3178                 }
3179
3180                 previous_data = *data;
3181                 sniffCounter++;
3182                 data++;
3183
3184                 if(data == dmaBuf + DMA_BUFFER_SIZE)
3185                         data = dmaBuf;
3186
3187         } // main cycle
3188
3189         FpgaDisableSscDma();
3190         MfSniffEnd();
3191         LEDsoff();
3192         Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len);
3193         set_tracing(FALSE);
3194 }