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 static uint32_t iso14a_timeout;
  24 int rsamples = 0;
  25 uint8_t trigger = 0;
  26 // the block number for the ISO14443-4 PCB
  27 static uint8_t iso14_pcb_blocknum = 0;
  28
  29 //
  30 // ISO14443 timing:
  31 //
  32 // minimum time between the start bits of consecutive transfers from reader to tag: 7000 carrier (13.56Mhz) cycles
  33 #define REQUEST_GUARD_TIME (7000/16 + 1)
  34 // minimum time between last modulation of tag and next start bit from reader to tag: 1172 carrier cycles
  35 #define FRAME_DELAY_TIME_PICC_TO_PCD (1172/16 + 1)
  36 // bool LastCommandWasRequest = FALSE;
  37
  38 //
  39 // Total delays including SSC-Transfers between ARM and FPGA. These are in carrier clock cycles (1/13,56MHz)
  40 //
  41 // When the PM acts as reader and is receiving tag data, it takes
  42 // 3 ticks delay in the AD converter
  43 // 16 ticks until the modulation detector completes and sets curbit
  44 // 8 ticks until bit_to_arm is assigned from curbit
  45 // 8*16 ticks for the transfer from FPGA to ARM
  46 // 4*16 ticks until we measure the time
  47 // - 8*16 ticks because we measure the time of the previous transfer
  48 #define DELAY_AIR2ARM_AS_READER (3 + 16 + 8 + 8*16 + 4*16 - 8*16)
  49
  50 // When the PM acts as a reader and is sending, it takes
  51 // 4*16 ticks until we can write data to the sending hold register
  52 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
  53 // 8 ticks until the first transfer starts
  54 // 8 ticks later the FPGA samples the data
  55 // 1 tick to assign mod_sig_coil
  56 #define DELAY_ARM2AIR_AS_READER (4*16 + 8*16 + 8 + 8 + 1)
  57
  58 // When the PM acts as tag and is receiving it takes
  59 // 2 ticks delay in the RF part (for the first falling edge),
  60 // 3 ticks for the A/D conversion,
  61 // 8 ticks on average until the start of the SSC transfer,
  62 // 8 ticks until the SSC samples the first data
  63 // 7*16 ticks to complete the transfer from FPGA to ARM
  64 // 8 ticks until the next ssp_clk rising edge
  65 // 4*16 ticks until we measure the time
  66 // - 8*16 ticks because we measure the time of the previous transfer
  67 #define DELAY_AIR2ARM_AS_TAG (2 + 3 + 8 + 8 + 7*16 + 8 + 4*16 - 8*16)
  68
  69 // The FPGA will report its internal sending delay in
  70 uint16_t FpgaSendQueueDelay;
  71 // the 5 first bits are the number of bits buffered in mod_sig_buf
  72 // the last three bits are the remaining ticks/2 after the mod_sig_buf shift
  73 #define DELAY_FPGA_QUEUE (FpgaSendQueueDelay<<1)
  74
  75 // When the PM acts as tag and is sending, it takes
  76 // 4*16 ticks until we can write data to the sending hold register
  77 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
  78 // 8 ticks until the first transfer starts
  79 // 8 ticks later the FPGA samples the data
  80 // + a varying number of ticks in the FPGA Delay Queue (mod_sig_buf)
  81 // + 1 tick to assign mod_sig_coil
  82 #define DELAY_ARM2AIR_AS_TAG (4*16 + 8*16 + 8 + 8 + DELAY_FPGA_QUEUE + 1)
  83
  84 // When the PM acts as sniffer and is receiving tag data, it takes
  85 // 3 ticks A/D conversion
  86 // 14 ticks to complete the modulation detection
  87 // 8 ticks (on average) until the result is stored in to_arm
  88 // + the delays in transferring data - which is the same for
  89 // sniffing reader and tag data and therefore not relevant
  90 #define DELAY_TAG_AIR2ARM_AS_SNIFFER (3 + 14 + 8)
  91
  92 // When the PM acts as sniffer and is receiving reader data, it takes
  93 // 2 ticks delay in analogue RF receiver (for the falling edge of the
  94 // start bit, which marks the start of the communication)
  95 // 3 ticks A/D conversion
  96 // 8 ticks on average until the data is stored in to_arm.
  97 // + the delays in transferring data - which is the same for
  98 // sniffing reader and tag data and therefore not relevant
  99 #define DELAY_READER_AIR2ARM_AS_SNIFFER (2 + 3 + 8)
 100
 101 //variables used for timing purposes:
 102 //these are in ssp_clk cycles:
 103 static uint32_t NextTransferTime;
 104 static uint32_t LastTimeProxToAirStart;
 105 static uint32_t LastProxToAirDuration;
 106
 107
 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 const uint8_t OddByteParity[256] = {
 125   1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
 126   0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
 127   0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
 128   1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
 129   0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
 130   1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
 131   1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
 132   0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
 133   0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
 134   1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
 135   1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
 136   0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
 137   1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1,
 138   0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
 139   0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0,
 140   1, 0, 0, 1, 0, 1, 1, 0, 0, 1, 1, 0, 1, 0, 0, 1
 141 };
 142
 143
 144 void iso14a_set_trigger(bool enable) {
 145         trigger = enable;
 146 }
 147
 148
 149 void iso14a_set_timeout(uint32_t timeout) {
 150         iso14a_timeout = timeout;
 151         if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443A Timeout set to %ld (%dms)", iso14a_timeout, iso14a_timeout / 106);
 152 }
 153
 154
 155 void iso14a_set_ATS_timeout(uint8_t *ats) {
 156
 157         uint8_t tb1;
 158         uint8_t fwi;
 159         uint32_t fwt;
 160
 161         if (ats[0] > 1) {                                                       // there is a format byte T0
 162                 if ((ats[1] & 0x20) == 0x20) {                  // there is an interface byte TB(1)
 163                         if ((ats[1] & 0x10) == 0x10) {          // there is an interface byte TA(1) preceding TB(1)
 164                                 tb1 = ats[3];
 165                         } else {
 166                                 tb1 = ats[2];
 167                         }
 168                         fwi = (tb1 & 0xf0) >> 4;                        // frame waiting indicator (FWI)
 169                         fwt = 256 * 16 * (1 << fwi);            // frame waiting time (FWT) in 1/fc
 170
 171                         iso14a_set_timeout(fwt/(8*16));
 172                 }
 173         }
 174 }
 175
 176
 177 //-----------------------------------------------------------------------------
 178 // Generate the parity value for a byte sequence
 179 //
 180 //-----------------------------------------------------------------------------
 181 byte_t oddparity (const byte_t bt)
 182 {
 183         return OddByteParity[bt];
 184 }
 185
 186 void GetParity(const uint8_t *pbtCmd, uint16_t iLen, uint8_t *par)
 187 {
 188         uint16_t paritybit_cnt = 0;
 189         uint16_t paritybyte_cnt = 0;
 190         uint8_t parityBits = 0;
 191
 192         for (uint16_t i = 0; i < iLen; i++) {
 193                 // Generate the parity bits
 194                 parityBits |= ((OddByteParity[pbtCmd[i]]) << (7-paritybit_cnt));
 195                 if (paritybit_cnt == 7) {
 196                         par[paritybyte_cnt] = parityBits;       // save 8 Bits parity
 197                         parityBits = 0;                                         // and advance to next Parity Byte
 198                         paritybyte_cnt++;
 199                         paritybit_cnt = 0;
 200                 } else {
 201                         paritybit_cnt++;
 202                 }
 203         }
 204
 205         // save remaining parity bits
 206         par[paritybyte_cnt] = parityBits;
 207
 208 }
 209
 210 void AppendCrc14443a(uint8_t* data, int len)
 211 {
 212         ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1);
 213 }
 214
 215 void AppendCrc14443b(uint8_t* data, int len)
 216 {
 217         ComputeCrc14443(CRC_14443_B,data,len,data+len,data+len+1);
 218 }
 219
 220
 221 //=============================================================================
 222 // ISO 14443 Type A - Miller decoder
 223 //=============================================================================
 224 // Basics:
 225 // This decoder is used when the PM3 acts as a tag.
 226 // The reader will generate "pauses" by temporarily switching of the field.
 227 // At the PM3 antenna we will therefore measure a modulated antenna voltage.
 228 // The FPGA does a comparison with a threshold and would deliver e.g.:
 229 // ........  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  .......
 230 // The Miller decoder needs to identify the following sequences:
 231 // 2 (or 3) ticks pause followed by 6 (or 5) ticks unmodulated:         pause at beginning - Sequence Z ("start of communication" or a "0")
 232 // 8 ticks without a modulation:                                                                        no pause - Sequence Y (a "0" or "end of communication" or "no information")
 233 // 4 ticks unmodulated followed by 2 (or 3) ticks pause:                        pause in second half - Sequence X (a "1")
 234 // Note 1: the bitstream may start at any time. We therefore need to sync.
 235 // Note 2: the interpretation of Sequence Y and Z depends on the preceding sequence.
 236 //-----------------------------------------------------------------------------
 237 static tUart Uart;
 238
 239 // Lookup-Table to decide if 4 raw bits are a modulation.
 240 // We accept the following:
 241 // 0001  -   a 3 tick wide pause
 242 // 0011  -   a 2 tick wide pause, or a three tick wide pause shifted left
 243 // 0111  -   a 2 tick wide pause shifted left
 244 // 1001  -   a 2 tick wide pause shifted right
 245 const bool Mod_Miller_LUT[] = {
 246         FALSE,  TRUE, FALSE, TRUE,  FALSE, FALSE, FALSE, TRUE,
 247         FALSE,  TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE
 248 };
 249 #define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x000000F0) >> 4])
 250 #define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x0000000F)])
 251
 252 void UartReset()
 253 {
 254         Uart.state = STATE_UNSYNCD;
 255         Uart.bitCount = 0;
 256         Uart.len = 0;                                           // number of decoded data bytes
 257         Uart.parityLen = 0;                                     // number of decoded parity bytes
 258         Uart.shiftReg = 0;                                      // shiftreg to hold decoded data bits
 259         Uart.parityBits = 0;                            // holds 8 parity bits
 260         Uart.startTime = 0;
 261         Uart.endTime = 0;
 262
 263         Uart.byteCntMax = 0;
 264         Uart.posCnt = 0;
 265         Uart.syncBit = 9999;
 266 }
 267
 268 void UartInit(uint8_t *data, uint8_t *parity)
 269 {
 270         Uart.output = data;
 271         Uart.parity = parity;
 272         Uart.fourBits = 0x00000000;                     // clear the buffer for 4 Bits
 273         UartReset();
 274 }
 275
 276 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
 277 static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time)
 278 {
 279
 280         Uart.fourBits = (Uart.fourBits << 8) | bit;
 281
 282         if (Uart.state == STATE_UNSYNCD) {                                                                                      // not yet synced
 283
 284                 Uart.syncBit = 9999;                                                                                                    // not set
 285
 286                 // 00x11111 2|3 ticks pause followed by 6|5 ticks unmodulated           Sequence Z (a "0" or "start of communication")
 287                 // 11111111 8 ticks unmodulation                                                                        Sequence Y (a "0" or "end of communication" or "no information")
 288                 // 111100x1 4 ticks unmodulated followed by 2|3 ticks pause                     Sequence X (a "1")
 289
 290                 // The start bit is one ore more Sequence Y followed by a Sequence Z (... 11111111 00x11111). We need to distinguish from
 291                 // Sequence X followed by Sequence Y followed by Sequence Z     (111100x1 11111111 00x11111)
 292                 // we therefore look for a ...xx1111 11111111 00x11111xxxxxx... pattern
 293                 // (12 '1's followed by 2 '0's, eventually followed by another '0', followed by 5 '1's)
 294                 //
 295 #define ISO14443A_STARTBIT_MASK         0x07FFEF80              // mask is    00001111 11111111 1110 1111 10000000
 296 #define ISO14443A_STARTBIT_PATTERN      0x07FF8F80              // pattern is 00001111 11111111 1000 1111 10000000
 297
 298                 if              ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 0)) == ISO14443A_STARTBIT_PATTERN >> 0) Uart.syncBit = 7;
 299                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 1)) == ISO14443A_STARTBIT_PATTERN >> 1) Uart.syncBit = 6;
 300                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 2)) == ISO14443A_STARTBIT_PATTERN >> 2) Uart.syncBit = 5;
 301                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 3)) == ISO14443A_STARTBIT_PATTERN >> 3) Uart.syncBit = 4;
 302                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 4)) == ISO14443A_STARTBIT_PATTERN >> 4) Uart.syncBit = 3;
 303                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 5)) == ISO14443A_STARTBIT_PATTERN >> 5) Uart.syncBit = 2;
 304                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 6)) == ISO14443A_STARTBIT_PATTERN >> 6) Uart.syncBit = 1;
 305                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 7)) == ISO14443A_STARTBIT_PATTERN >> 7) Uart.syncBit = 0;
 306
 307                 if (Uart.syncBit != 9999) {                                                                                             // found a sync bit
 308                                 Uart.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
 309                                 Uart.startTime -= Uart.syncBit;
 310                                 Uart.endTime = Uart.startTime;
 311                                 Uart.state = STATE_START_OF_COMMUNICATION;
 312                         }
 313
 314         } else {
 315
 316                 if (IsMillerModulationNibble1(Uart.fourBits >> Uart.syncBit)) {
 317                         if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) {         // Modulation in both halves - error
 318                                 UartReset();
 319                         } else {                                                                                                                        // Modulation in first half = Sequence Z = logic "0"
 320                                 if (Uart.state == STATE_MILLER_X) {                                                             // error - must not follow after X
 321                                         UartReset();
 322                                 } else {
 323                                         Uart.bitCount++;
 324                                         Uart.shiftReg = (Uart.shiftReg >> 1);                                           // add a 0 to the shiftreg
 325                                         Uart.state = STATE_MILLER_Z;
 326                                         Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 6;
 327                                         if(Uart.bitCount >= 9) {                                                                        // if we decoded a full byte (including parity)
 328                                                 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
 329                                                 Uart.parityBits <<= 1;                                                                  // make room for the parity bit
 330                                                 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01);               // store parity bit
 331                                                 Uart.bitCount = 0;
 332                                                 Uart.shiftReg = 0;
 333                                                 if((Uart.len&0x0007) == 0) {                                                    // every 8 data bytes
 334                                                         Uart.parity[Uart.parityLen++] = Uart.parityBits;        // store 8 parity bits
 335                                                         Uart.parityBits = 0;
 336                                                 }
 337                                         }
 338                                 }
 339                         }
 340                 } else {
 341                         if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) {         // Modulation second half = Sequence X = logic "1"
 342                                 Uart.bitCount++;
 343                                 Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100;                                   // add a 1 to the shiftreg
 344                                 Uart.state = STATE_MILLER_X;
 345                                 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 2;
 346                                 if(Uart.bitCount >= 9) {                                                                                // if we decoded a full byte (including parity)
 347                                         Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
 348                                         Uart.parityBits <<= 1;                                                                          // make room for the new parity bit
 349                                         Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01);                       // store parity bit
 350                                         Uart.bitCount = 0;
 351                                         Uart.shiftReg = 0;
 352                                         if ((Uart.len&0x0007) == 0) {                                                           // every 8 data bytes
 353                                                 Uart.parity[Uart.parityLen++] = Uart.parityBits;                // store 8 parity bits
 354                                                 Uart.parityBits = 0;
 355                                         }
 356                                 }
 357                         } else {                                                                                                                        // no modulation in both halves - Sequence Y
 358                                 if (Uart.state == STATE_MILLER_Z || Uart.state == STATE_MILLER_Y) {     // Y after logic "0" - End of Communication
 359                                         Uart.state = STATE_UNSYNCD;
 360                                         Uart.bitCount--;                                                                                        // last "0" was part of EOC sequence
 361                                         Uart.shiftReg <<= 1;                                                                            // drop it
 362                                         if(Uart.bitCount > 0) {                                                                         // if we decoded some bits
 363                                                 Uart.shiftReg >>= (9 - Uart.bitCount);                                  // right align them
 364                                                 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);               // add last byte to the output
 365                                                 Uart.parityBits <<= 1;                                                                  // add a (void) parity bit
 366                                                 Uart.parityBits <<= (8 - (Uart.len&0x0007));                    // left align parity bits
 367                                                 Uart.parity[Uart.parityLen++] = Uart.parityBits;                // and store it
 368                                                 return TRUE;
 369                                         } else if (Uart.len & 0x0007) {                                                         // there are some parity bits to store
 370                                                 Uart.parityBits <<= (8 - (Uart.len&0x0007));                    // left align remaining parity bits
 371                                                 Uart.parity[Uart.parityLen++] = Uart.parityBits;                // and store them
 372                                         }
 373                                         if (Uart.len) {
 374                                                 return TRUE;                                                                                    // we are finished with decoding the raw data sequence
 375                                         } else {
 376                                                 UartReset();                                                                                    // Nothing received - start over
 377                                         }
 378                                 }
 379                                 if (Uart.state == STATE_START_OF_COMMUNICATION) {                               // error - must not follow directly after SOC
 380                                         UartReset();
 381                                 } else {                                                                                                                // a logic "0"
 382                                         Uart.bitCount++;
 383                                         Uart.shiftReg = (Uart.shiftReg >> 1);                                           // add a 0 to the shiftreg
 384                                         Uart.state = STATE_MILLER_Y;
 385                                         if(Uart.bitCount >= 9) {                                                                        // if we decoded a full byte (including parity)
 386                                                 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
 387                                                 Uart.parityBits <<= 1;                                                                  // make room for the parity bit
 388                                                 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01);               // store parity bit
 389                                                 Uart.bitCount = 0;
 390                                                 Uart.shiftReg = 0;
 391                                                 if ((Uart.len&0x0007) == 0) {                                                   // every 8 data bytes
 392                                                         Uart.parity[Uart.parityLen++] = Uart.parityBits;        // store 8 parity bits
 393                                                         Uart.parityBits = 0;
 394                                                 }
 395                                         }
 396                                 }
 397                         }
 398                 }
 399
 400         }
 401
 402     return FALSE;       // not finished yet, need more data
 403 }
 404
 405
 406
 407 //=============================================================================
 408 // ISO 14443 Type A - Manchester decoder
 409 //=============================================================================
 410 // Basics:
 411 // This decoder is used when the PM3 acts as a reader.
 412 // The tag will modulate the reader field by asserting different loads to it. As a consequence, the voltage
 413 // at the reader antenna will be modulated as well. The FPGA detects the modulation for us and would deliver e.g. the following:
 414 // ........ 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 .......
 415 // The Manchester decoder needs to identify the following sequences:
 416 // 4 ticks modulated followed by 4 ticks unmodulated:   Sequence D = 1 (also used as "start of communication")
 417 // 4 ticks unmodulated followed by 4 ticks modulated:   Sequence E = 0
 418 // 8 ticks unmodulated:                                                                 Sequence F = end of communication
 419 // 8 ticks modulated:                                                                   A collision. Save the collision position and treat as Sequence D
 420 // Note 1: the bitstream may start at any time. We therefore need to sync.
 421 // Note 2: parameter offset is used to determine the position of the parity bits (required for the anticollision command only)
 422 static tDemod Demod;
 423
 424 // Lookup-Table to decide if 4 raw bits are a modulation.
 425 // We accept three or four "1" in any position
 426 const bool Mod_Manchester_LUT[] = {
 427         FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE,
 428         FALSE, FALSE, FALSE, TRUE,  FALSE, TRUE,  TRUE,  TRUE
 429 };
 430
 431 #define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4])
 432 #define IsManchesterModulationNibble2(b) (Mod_Manchester_LUT[(b & 0x000F)])
 433
 434
 435 void DemodReset()
 436 {
 437         Demod.state = DEMOD_UNSYNCD;
 438         Demod.len = 0;                                          // number of decoded data bytes
 439         Demod.parityLen = 0;
 440         Demod.shiftReg = 0;                                     // shiftreg to hold decoded data bits
 441         Demod.parityBits = 0;                           //
 442         Demod.collisionPos = 0;                         // Position of collision bit
 443         Demod.twoBits = 0xffff;                         // buffer for 2 Bits
 444         Demod.highCnt = 0;
 445         Demod.startTime = 0;
 446         Demod.endTime = 0;
 447
 448         //
 449         Demod.bitCount = 0;
 450         Demod.syncBit = 0xFFFF;
 451         Demod.samples = 0;
 452 }
 453
 454 void DemodInit(uint8_t *data, uint8_t *parity)
 455 {
 456         Demod.output = data;
 457         Demod.parity = parity;
 458         DemodReset();
 459 }
 460
 461 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
 462 static RAMFUNC int ManchesterDecoding(uint8_t bit, uint16_t offset, uint32_t non_real_time)
 463 {
 464
 465         Demod.twoBits = (Demod.twoBits << 8) | bit;
 466
 467         if (Demod.state == DEMOD_UNSYNCD) {
 468
 469                 if (Demod.highCnt < 2) {                                                                                        // wait for a stable unmodulated signal
 470                         if (Demod.twoBits == 0x0000) {
 471                                 Demod.highCnt++;
 472                         } else {
 473                                 Demod.highCnt = 0;
 474                         }
 475                 } else {
 476                         Demod.syncBit = 0xFFFF;                 // not set
 477                         if              ((Demod.twoBits & 0x7700) == 0x7000) Demod.syncBit = 7;
 478                         else if ((Demod.twoBits & 0x3B80) == 0x3800) Demod.syncBit = 6;
 479                         else if ((Demod.twoBits & 0x1DC0) == 0x1C00) Demod.syncBit = 5;
 480                         else if ((Demod.twoBits & 0x0EE0) == 0x0E00) Demod.syncBit = 4;
 481                         else if ((Demod.twoBits & 0x0770) == 0x0700) Demod.syncBit = 3;
 482                         else if ((Demod.twoBits & 0x03B8) == 0x0380) Demod.syncBit = 2;
 483                         else if ((Demod.twoBits & 0x01DC) == 0x01C0) Demod.syncBit = 1;
 484                         else if ((Demod.twoBits & 0x00EE) == 0x00E0) Demod.syncBit = 0;
 485                         if (Demod.syncBit != 0xFFFF) {
 486                                 Demod.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
 487                                 Demod.startTime -= Demod.syncBit;
 488                                 Demod.bitCount = offset;                        // number of decoded data bits
 489                                 Demod.state = DEMOD_MANCHESTER_DATA;
 490                         }
 491                 }
 492
 493         } else {
 494
 495                 if (IsManchesterModulationNibble1(Demod.twoBits >> Demod.syncBit)) {            // modulation in first half
 496                         if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) {    // ... and in second half = collision
 497                                 if (!Demod.collisionPos) {
 498                                         Demod.collisionPos = (Demod.len << 3) + Demod.bitCount;
 499                                 }
 500                         }                                                                                                                       // modulation in first half only - Sequence D = 1
 501                         Demod.bitCount++;
 502                         Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100;                         // in both cases, add a 1 to the shiftreg
 503                         if(Demod.bitCount == 9) {                                                                       // if we decoded a full byte (including parity)
 504                                 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
 505                                 Demod.parityBits <<= 1;                                                                 // make room for the parity bit
 506                                 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01);     // store parity bit
 507                                 Demod.bitCount = 0;
 508                                 Demod.shiftReg = 0;
 509                                 if((Demod.len&0x0007) == 0) {                                                   // every 8 data bytes
 510                                         Demod.parity[Demod.parityLen++] = Demod.parityBits;     // store 8 parity bits
 511                                         Demod.parityBits = 0;
 512                                 }
 513                         }
 514                         Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1) - 4;
 515                 } else {                                                                                                                // no modulation in first half
 516                         if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) {    // and modulation in second half = Sequence E = 0
 517                                 Demod.bitCount++;
 518                                 Demod.shiftReg = (Demod.shiftReg >> 1);                                 // add a 0 to the shiftreg
 519                                 if(Demod.bitCount >= 9) {                                                               // if we decoded a full byte (including parity)
 520                                         Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
 521                                         Demod.parityBits <<= 1;                                                         // make room for the new parity bit
 522                                         Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
 523                                         Demod.bitCount = 0;
 524                                         Demod.shiftReg = 0;
 525                                         if ((Demod.len&0x0007) == 0) {                                          // every 8 data bytes
 526                                                 Demod.parity[Demod.parityLen++] = Demod.parityBits;     // store 8 parity bits1
 527                                                 Demod.parityBits = 0;
 528                                         }
 529                                 }
 530                                 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1);
 531                         } else {                                                                                                        // no modulation in both halves - End of communication
 532                                 if(Demod.bitCount > 0) {                                                                // there are some remaining data bits
 533                                         Demod.shiftReg >>= (9 - Demod.bitCount);                        // right align the decoded bits
 534                                         Demod.output[Demod.len++] = Demod.shiftReg & 0xff;      // and add them to the output
 535                                         Demod.parityBits <<= 1;                                                         // add a (void) parity bit
 536                                         Demod.parityBits <<= (8 - (Demod.len&0x0007));          // left align remaining parity bits
 537                                         Demod.parity[Demod.parityLen++] = Demod.parityBits;     // and store them
 538                                         return TRUE;
 539                                 } else if (Demod.len & 0x0007) {                                                // there are some parity bits to store
 540                                         Demod.parityBits <<= (8 - (Demod.len&0x0007));          // left align remaining parity bits
 541                                         Demod.parity[Demod.parityLen++] = Demod.parityBits;     // and store them
 542                                 }
 543                                 if (Demod.len) {
 544                                         return TRUE;                                                                            // we are finished with decoding the raw data sequence
 545                                 } else {                                                                                                // nothing received. Start over
 546                                         DemodReset();
 547                                 }
 548                         }
 549                 }
 550         }
 551     return FALSE;       // not finished yet, need more data
 552 }
 553
 554 //=============================================================================
 555 // Finally, a `sniffer' for ISO 14443 Type A
 556 // Both sides of communication!
 557 //=============================================================================
 558
 559 //-----------------------------------------------------------------------------
 560 // Record the sequence of commands sent by the reader to the tag, with
 561 // triggering so that we start recording at the point that the tag is moved
 562 // near the reader.
 563 //-----------------------------------------------------------------------------
 564 void RAMFUNC SniffIso14443a(uint8_t param) {
 565         // param:
 566         // bit 0 - trigger from first card answer
 567         // bit 1 - trigger from first reader 7-bit request
 568         LEDsoff();
 569
 570         iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
 571
 572         // Allocate memory from BigBuf for some buffers
 573         // free all previous allocations first
 574         BigBuf_free();
 575
 576         // init trace buffer
 577         clear_trace();
 578         set_tracing(TRUE);
 579
 580         // The command (reader -> tag) that we're receiving.
 581         uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
 582         uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
 583
 584         // The response (tag -> reader) that we're receiving.
 585         uint8_t *receivedResponse = BigBuf_malloc(MAX_FRAME_SIZE);
 586         uint8_t *receivedResponsePar = BigBuf_malloc(MAX_PARITY_SIZE);
 587
 588         // The DMA buffer, used to stream samples from the FPGA
 589         uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
 590
 591         uint8_t *data = dmaBuf;
 592         uint8_t previous_data = 0;
 593         int maxDataLen = 0;
 594         int dataLen = 0;
 595         bool TagIsActive = FALSE;
 596         bool ReaderIsActive = FALSE;
 597
 598         // Set up the demodulator for tag -> reader responses.
 599         DemodInit(receivedResponse, receivedResponsePar);
 600
 601         // Set up the demodulator for the reader -> tag commands
 602         UartInit(receivedCmd, receivedCmdPar);
 603
 604         // Setup and start DMA.
 605         FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE);
 606
 607         // We won't start recording the frames that we acquire until we trigger;
 608         // a good trigger condition to get started is probably when we see a
 609         // response from the tag.
 610         // triggered == FALSE -- to wait first for card
 611         bool triggered = !(param & 0x03);
 612
 613         // And now we loop, receiving samples.
 614         for(uint32_t rsamples = 0; TRUE; ) {
 615
 616                 if(BUTTON_PRESS()) {
 617                         DbpString("cancelled by button");
 618                         break;
 619                 }
 620
 621                 LED_A_ON();
 622                 WDT_HIT();
 623
 624                 int register readBufDataP = data - dmaBuf;
 625                 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR;
 626                 if (readBufDataP <= dmaBufDataP){
 627                         dataLen = dmaBufDataP - readBufDataP;
 628                 } else {
 629                         dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP;
 630                 }
 631                 // test for length of buffer
 632                 if(dataLen > maxDataLen) {
 633                         maxDataLen = dataLen;
 634                         if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
 635                                 Dbprintf("blew circular buffer! dataLen=%d", dataLen);
 636                                 break;
 637                         }
 638                 }
 639                 if(dataLen < 1) continue;
 640
 641                 // primary buffer was stopped( <-- we lost data!
 642                 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
 643                         AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
 644                         AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
 645                         Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
 646                 }
 647                 // secondary buffer sets as primary, secondary buffer was stopped
 648                 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
 649                         AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
 650                         AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
 651                 }
 652
 653                 LED_A_OFF();
 654
 655                 if (rsamples & 0x01) {                          // Need two samples to feed Miller and Manchester-Decoder
 656
 657                         if(!TagIsActive) {              // no need to try decoding reader data if the tag is sending
 658                                 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
 659                                 if (MillerDecoding(readerdata, (rsamples-1)*4)) {
 660                                         LED_C_ON();
 661
 662                                         // check - if there is a short 7bit request from reader
 663                                         if ((!triggered) && (param & 0x02) && (Uart.len == 1) && (Uart.bitCount == 7)) triggered = TRUE;
 664
 665                                         if(triggered) {
 666                                                 if (!LogTrace(receivedCmd,
 667                                                                                 Uart.len,
 668                                                                                 Uart.startTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
 669                                                                                 Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
 670                                                                                 Uart.parity,
 671                                                                                 TRUE)) break;
 672                                         }
 673                                         /* And ready to receive another command. */
 674                                         UartReset();
 675                                         /* And also reset the demod code, which might have been */
 676                                         /* false-triggered by the commands from the reader. */
 677                                         DemodReset();
 678                                         LED_B_OFF();
 679                                 }
 680                                 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
 681                         }
 682
 683                         if(!ReaderIsActive) {           // no need to try decoding tag data if the reader is sending - and we cannot afford the time
 684                                 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
 685                                 if(ManchesterDecoding(tagdata, 0, (rsamples-1)*4)) {
 686                                         LED_B_ON();
 687
 688                                         if (!LogTrace(receivedResponse,
 689                                                                         Demod.len,
 690                                                                         Demod.startTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
 691                                                                         Demod.endTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
 692                                                                         Demod.parity,
 693                                                                         FALSE)) break;
 694
 695                                         if ((!triggered) && (param & 0x01)) triggered = TRUE;
 696
 697                                         // And ready to receive another response.
 698                                         DemodReset();
 699                                         // And reset the Miller decoder including itS (now outdated) input buffer
 700                                         UartInit(receivedCmd, receivedCmdPar);
 701
 702                                         LED_C_OFF();
 703                                 }
 704                                 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
 705                         }
 706                 }
 707
 708                 previous_data = *data;
 709                 rsamples++;
 710                 data++;
 711                 if(data == dmaBuf + DMA_BUFFER_SIZE) {
 712                         data = dmaBuf;
 713                 }
 714         } // main cycle
 715
 716         FpgaDisableSscDma();
 717         LEDsoff();
 718
 719         Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len);
 720         Dbprintf("traceLen=%d, Uart.output[0]=%08x", BigBuf_get_traceLen(), (uint32_t)Uart.output[0]);
 721 }
 722
 723 //-----------------------------------------------------------------------------
 724 // Prepare tag messages
 725 //-----------------------------------------------------------------------------
 726 static void CodeIso14443aAsTagPar(const uint8_t *cmd, uint16_t len, uint8_t *parity)
 727 {
 728         ToSendReset();
 729
 730         // Correction bit, might be removed when not needed
 731         ToSendStuffBit(0);
 732         ToSendStuffBit(0);
 733         ToSendStuffBit(0);
 734         ToSendStuffBit(0);
 735         ToSendStuffBit(1);  // 1
 736         ToSendStuffBit(0);
 737         ToSendStuffBit(0);
 738         ToSendStuffBit(0);
 739
 740         // Send startbit
 741         ToSend[++ToSendMax] = SEC_D;
 742         LastProxToAirDuration = 8 * ToSendMax - 4;
 743
 744         for(uint16_t i = 0; i < len; i++) {
 745                 uint8_t b = cmd[i];
 746
 747                 // Data bits
 748                 for(uint16_t j = 0; j < 8; j++) {
 749                         if(b & 1) {
 750                                 ToSend[++ToSendMax] = SEC_D;
 751                         } else {
 752                                 ToSend[++ToSendMax] = SEC_E;
 753                         }
 754                         b >>= 1;
 755                 }
 756
 757                 // Get the parity bit
 758                 if (parity[i>>3] & (0x80>>(i&0x0007))) {
 759                         ToSend[++ToSendMax] = SEC_D;
 760                         LastProxToAirDuration = 8 * ToSendMax - 4;
 761                 } else {
 762                         ToSend[++ToSendMax] = SEC_E;
 763                         LastProxToAirDuration = 8 * ToSendMax;
 764                 }
 765         }
 766
 767         // Send stopbit
 768         ToSend[++ToSendMax] = SEC_F;
 769
 770         // Convert from last byte pos to length
 771         ToSendMax++;
 772 }
 773
 774 static void CodeIso14443aAsTag(const uint8_t *cmd, uint16_t len)
 775 {
 776         uint8_t par[MAX_PARITY_SIZE];
 777
 778         GetParity(cmd, len, par);
 779         CodeIso14443aAsTagPar(cmd, len, par);
 780 }
 781
 782
 783 static void Code4bitAnswerAsTag(uint8_t cmd)
 784 {
 785         int i;
 786
 787         ToSendReset();
 788
 789         // Correction bit, might be removed when not needed
 790         ToSendStuffBit(0);
 791         ToSendStuffBit(0);
 792         ToSendStuffBit(0);
 793         ToSendStuffBit(0);
 794         ToSendStuffBit(1);  // 1
 795         ToSendStuffBit(0);
 796         ToSendStuffBit(0);
 797         ToSendStuffBit(0);
 798
 799         // Send startbit
 800         ToSend[++ToSendMax] = SEC_D;
 801
 802         uint8_t b = cmd;
 803         for(i = 0; i < 4; i++) {
 804                 if(b & 1) {
 805                         ToSend[++ToSendMax] = SEC_D;
 806                         LastProxToAirDuration = 8 * ToSendMax - 4;
 807                 } else {
 808                         ToSend[++ToSendMax] = SEC_E;
 809                         LastProxToAirDuration = 8 * ToSendMax;
 810                 }
 811                 b >>= 1;
 812         }
 813
 814         // Send stopbit
 815         ToSend[++ToSendMax] = SEC_F;
 816
 817         // Convert from last byte pos to length
 818         ToSendMax++;
 819 }
 820
 821 //-----------------------------------------------------------------------------
 822 // Wait for commands from reader
 823 // Stop when button is pressed
 824 // Or return TRUE when command is captured
 825 //-----------------------------------------------------------------------------
 826 static int GetIso14443aCommandFromReader(uint8_t *received, uint8_t *parity, int *len)
 827 {
 828     // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
 829     // only, since we are receiving, not transmitting).
 830     // Signal field is off with the appropriate LED
 831     LED_D_OFF();
 832     FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
 833
 834     // Now run a `software UART' on the stream of incoming samples.
 835         UartInit(received, parity);
 836
 837         // clear RXRDY:
 838     uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
 839
 840     for(;;) {
 841         WDT_HIT();
 842
 843         if(BUTTON_PRESS()) return FALSE;
 844
 845         if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
 846             b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
 847                         if(MillerDecoding(b, 0)) {
 848                                 *len = Uart.len;
 849                                 return TRUE;
 850                         }
 851                 }
 852     }
 853 }
 854
 855 static int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen, bool correctionNeeded);
 856 int EmSend4bitEx(uint8_t resp, bool correctionNeeded);
 857 int EmSend4bit(uint8_t resp);
 858 int EmSendCmdExPar(uint8_t *resp, uint16_t respLen, bool correctionNeeded, uint8_t *par);
 859 int EmSendCmdEx(uint8_t *resp, uint16_t respLen, bool correctionNeeded);
 860 int EmSendCmd(uint8_t *resp, uint16_t respLen);
 861 int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par);
 862 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
 863                                  uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity);
 864
 865 static uint8_t* free_buffer_pointer;
 866
 867 typedef struct {
 868   uint8_t* response;
 869   size_t   response_n;
 870   uint8_t* modulation;
 871   size_t   modulation_n;
 872   uint32_t ProxToAirDuration;
 873 } tag_response_info_t;
 874
 875 bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) {
 876         // Example response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes
 877         // This will need the following byte array for a modulation sequence
 878         //    144        data bits (18 * 8)
 879         //     18        parity bits
 880         //      2        Start and stop
 881         //      1        Correction bit (Answer in 1172 or 1236 periods, see FPGA)
 882         //      1        just for the case
 883         // ----------- +
 884         //    166 bytes, since every bit that needs to be send costs us a byte
 885         //
 886
 887
 888   // Prepare the tag modulation bits from the message
 889   CodeIso14443aAsTag(response_info->response,response_info->response_n);
 890
 891   // Make sure we do not exceed the free buffer space
 892   if (ToSendMax > max_buffer_size) {
 893     Dbprintf("Out of memory, when modulating bits for tag answer:");
 894     Dbhexdump(response_info->response_n,response_info->response,false);
 895     return false;
 896   }
 897
 898   // Copy the byte array, used for this modulation to the buffer position
 899   memcpy(response_info->modulation,ToSend,ToSendMax);
 900
 901   // Store the number of bytes that were used for encoding/modulation and the time needed to transfer them
 902   response_info->modulation_n = ToSendMax;
 903   response_info->ProxToAirDuration = LastProxToAirDuration;
 904
 905   return true;
 906 }
 907
 908
 909 // "precompile" responses. There are 7 predefined responses with a total of 28 bytes data to transmit.
 910 // Coded responses need one byte per bit to transfer (data, parity, start, stop, correction)
 911 // 28 * 8 data bits, 28 * 1 parity bits, 7 start bits, 7 stop bits, 7 correction bits
 912 // -> need 273 bytes buffer
 913 // 44 * 8 data bits, 44 * 1 parity bits, 9 start bits, 9 stop bits, 9 correction bits --370
 914 // 47 * 8 data bits, 47 * 1 parity bits, 10 start bits, 10 stop bits, 10 correction bits
 915 #define ALLOCATED_TAG_MODULATION_BUFFER_SIZE 453
 916
 917 bool prepare_allocated_tag_modulation(tag_response_info_t* response_info) {
 918   // Retrieve and store the current buffer index
 919   response_info->modulation = free_buffer_pointer;
 920
 921   // Determine the maximum size we can use from our buffer
 922   size_t max_buffer_size = ALLOCATED_TAG_MODULATION_BUFFER_SIZE;
 923
 924   // Forward the prepare tag modulation function to the inner function
 925   if (prepare_tag_modulation(response_info, max_buffer_size)) {
 926     // Update the free buffer offset
 927     free_buffer_pointer += ToSendMax;
 928     return true;
 929   } else {
 930     return false;
 931   }
 932 }
 933
 934 //-----------------------------------------------------------------------------
 935 // Main loop of simulated tag: receive commands from reader, decide what
 936 // response to send, and send it.
 937 //-----------------------------------------------------------------------------
 938 void SimulateIso14443aTag(int tagType, int flags, byte_t* data)
 939 {
 940
 941         //Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2
 942         // This can be used in a reader-only attack.
 943         // (it can also be retrieved via 'hf 14a list', but hey...
 944         uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0,0,0};
 945         uint8_t ar_nr_collected = 0;
 946
 947         uint8_t sak;
 948
 949         // PACK response to PWD AUTH for EV1/NTAG
 950         uint8_t response8[4];
 951
 952         // The first response contains the ATQA (note: bytes are transmitted in reverse order).
 953         uint8_t response1[2];
 954
 955         switch (tagType) {
 956                 case 1: { // MIFARE Classic
 957                         // Says: I am Mifare 1k - original line
 958                         response1[0] = 0x04;
 959                         response1[1] = 0x00;
 960                         sak = 0x08;
 961                 } break;
 962                 case 2: { // MIFARE Ultralight
 963                         // Says: I am a stupid memory tag, no crypto
 964                         response1[0] = 0x44;
 965                         response1[1] = 0x00;
 966                         sak = 0x00;
 967                 } break;
 968                 case 3: { // MIFARE DESFire
 969                         // Says: I am a DESFire tag, ph33r me
 970                         response1[0] = 0x04;
 971                         response1[1] = 0x03;
 972                         sak = 0x20;
 973                 } break;
 974                 case 4: { // ISO/IEC 14443-4
 975                         // Says: I am a javacard (JCOP)
 976                         response1[0] = 0x04;
 977                         response1[1] = 0x00;
 978                         sak = 0x28;
 979                 } break;
 980                 case 5: { // MIFARE TNP3XXX
 981                         // Says: I am a toy
 982                         response1[0] = 0x01;
 983                         response1[1] = 0x0f;
 984                         sak = 0x01;
 985                 } break;
 986                 case 6: { // MIFARE Mini
 987                         // Says: I am a Mifare Mini, 320b
 988                         response1[0] = 0x44;
 989                         response1[1] = 0x00;
 990                         sak = 0x09;
 991                 } break;
 992                 case 7: { // NTAG?
 993                         // Says: I am a NTAG,
 994                         response1[0] = 0x44;
 995                         response1[1] = 0x00;
 996                         sak = 0x00;
 997                         // PACK
 998                         response8[0] = 0x80;
 999                         response8[1] = 0x80;
1000                         ComputeCrc14443(CRC_14443_A, response8, 2, &response8[2], &response8[3]);
1001                 } break;
1002                 default: {
1003                         Dbprintf("Error: unkown tagtype (%d)",tagType);
1004                         return;
1005                 } break;
1006         }
1007
1008         // The second response contains the (mandatory) first 24 bits of the UID
1009         uint8_t response2[5] = {0x00};
1010
1011         // Check if the uid uses the (optional) part
1012         uint8_t response2a[5] = {0x00};
1013
1014         if (flags & FLAG_7B_UID_IN_DATA) {
1015                 response2[0] = 0x88;
1016                 response2[1] = data[0];
1017                 response2[2] = data[1];
1018                 response2[3] = data[2];
1019
1020                 response2a[0] = data[3];
1021                 response2a[1] = data[4];
1022                 response2a[2] = data[5];
1023                 response2a[3] = data[6]; //??
1024                 response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3];
1025
1026                 // Configure the ATQA and SAK accordingly
1027                 response1[0] |= 0x40;
1028                 sak |= 0x04;
1029         } else {
1030                 memcpy(response2, data, 4);
1031                 //num_to_bytes(uid_1st,4,response2);
1032                 // Configure the ATQA and SAK accordingly
1033                 response1[0] &= 0xBF;
1034                 sak &= 0xFB;
1035         }
1036
1037         // Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID.
1038         response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3];
1039
1040         // Prepare the mandatory SAK (for 4 and 7 byte UID)
1041         uint8_t response3[3]  = {0x00};
1042         response3[0] = sak;
1043         ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
1044
1045         // Prepare the optional second SAK (for 7 byte UID), drop the cascade bit
1046         uint8_t response3a[3]  = {0x00};
1047         response3a[0] = sak & 0xFB;
1048         ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
1049
1050         uint8_t response5[] = { 0x01, 0x01, 0x01, 0x01 }; // Very random tag nonce
1051         uint8_t response6[] = { 0x04, 0x58, 0x80, 0x02, 0x00, 0x00 }; // dummy ATS (pseudo-ATR), answer to RATS:
1052         // Format byte = 0x58: FSCI=0x08 (FSC=256), TA(1) and TC(1) present,
1053         // TA(1) = 0x80: different divisors not supported, DR = 1, DS = 1
1054         // 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)
1055         // TC(1) = 0x02: CID supported, NAD not supported
1056         ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]);
1057
1058         // Prepare GET_VERSION (different for EV-1 / NTAG)
1059         //uint8_t response7_EV1[] = {0x00, 0x04, 0x03, 0x01, 0x01, 0x00, 0x0b, 0x03, 0xfd, 0xf7};  //EV1 48bytes VERSION.
1060         uint8_t response7_NTAG[] = {0x00, 0x04, 0x04, 0x02, 0x01, 0x00, 0x11, 0x03, 0x01, 0x9e}; //NTAG 215
1061
1062         // Prepare CHK_TEARING
1063         uint8_t response9[] =  {0xBD,0x90,0x3f};
1064
1065         #define TAG_RESPONSE_COUNT 10
1066         tag_response_info_t responses[TAG_RESPONSE_COUNT] = {
1067                 { .response = response1,  .response_n = sizeof(response1)  },  // Answer to request - respond with card type
1068                 { .response = response2,  .response_n = sizeof(response2)  },  // Anticollision cascade1 - respond with uid
1069                 { .response = response2a, .response_n = sizeof(response2a) },  // Anticollision cascade2 - respond with 2nd half of uid if asked
1070                 { .response = response3,  .response_n = sizeof(response3)  },  // Acknowledge select - cascade 1
1071                 { .response = response3a, .response_n = sizeof(response3a) },  // Acknowledge select - cascade 2
1072                 { .response = response5,  .response_n = sizeof(response5)  },  // Authentication answer (random nonce)
1073                 { .response = response6,  .response_n = sizeof(response6)  },  // dummy ATS (pseudo-ATR), answer to RATS
1074                 { .response = response7_NTAG,  .response_n = sizeof(response7_NTAG)  },  // EV1/NTAG GET_VERSION response
1075                 { .response = response8,   .response_n = sizeof(response8) },  // EV1/NTAG PACK response
1076                 { .response = response9,   .response_n = sizeof(response9) }  // EV1/NTAG CHK_TEAR response
1077         };
1078
1079         // Allocate 512 bytes for the dynamic modulation, created when the reader queries for it
1080         // Such a response is less time critical, so we can prepare them on the fly
1081         #define DYNAMIC_RESPONSE_BUFFER_SIZE 64
1082         #define DYNAMIC_MODULATION_BUFFER_SIZE 512
1083         uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
1084         uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
1085         tag_response_info_t dynamic_response_info = {
1086                 .response = dynamic_response_buffer,
1087                 .response_n = 0,
1088                 .modulation = dynamic_modulation_buffer,
1089                 .modulation_n = 0
1090         };
1091
1092         // We need to listen to the high-frequency, peak-detected path.
1093         iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1094
1095         BigBuf_free_keep_EM();
1096
1097         // allocate buffers:
1098         uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
1099         uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
1100         free_buffer_pointer = BigBuf_malloc(ALLOCATED_TAG_MODULATION_BUFFER_SIZE);
1101
1102         // clear trace
1103         clear_trace();
1104         set_tracing(TRUE);
1105
1106         // Prepare the responses of the anticollision phase
1107         // there will be not enough time to do this at the moment the reader sends it REQA
1108         for (size_t i=0; i<TAG_RESPONSE_COUNT; i++) {
1109                 prepare_allocated_tag_modulation(&responses[i]);
1110         }
1111
1112         int len = 0;
1113
1114         // To control where we are in the protocol
1115         int order = 0;
1116         int lastorder;
1117
1118         // Just to allow some checks
1119         int happened = 0;
1120         int happened2 = 0;
1121         int cmdsRecvd = 0;
1122
1123         cmdsRecvd = 0;
1124         tag_response_info_t* p_response;
1125
1126         LED_A_ON();
1127         for(;;) {
1128                 // Clean receive command buffer
1129
1130                 if(!GetIso14443aCommandFromReader(receivedCmd, receivedCmdPar, &len)) {
1131                         DbpString("Button press");
1132                         break;
1133                 }
1134
1135                 p_response = NULL;
1136
1137                 // Okay, look at the command now.
1138                 lastorder = order;
1139                 if(receivedCmd[0] == 0x26) { // Received a REQUEST
1140                         p_response = &responses[0]; order = 1;
1141                 } else if(receivedCmd[0] == 0x52) { // Received a WAKEUP
1142                         p_response = &responses[0]; order = 6;
1143                 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) {   // Received request for UID (cascade 1)
1144                         p_response = &responses[1]; order = 2;
1145                 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x95) {   // Received request for UID (cascade 2)
1146                         p_response = &responses[2]; order = 20;
1147                 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x93) {   // Received a SELECT (cascade 1)
1148                         p_response = &responses[3]; order = 3;
1149                 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x95) {   // Received a SELECT (cascade 2)
1150                         p_response = &responses[4]; order = 30;
1151                 } else if(receivedCmd[0] == 0x30) {     // Received a (plain) READ
1152                         uint8_t block = receivedCmd[1];
1153                         if ( tagType == 7 ) {
1154                                 uint8_t start = 4 * block;
1155
1156                                 if ( block < 4 ) {
1157                                     //NTAG 215
1158                                         uint8_t blockdata[50] = {
1159                                         data[0],data[1],data[2], 0x88 ^ data[0] ^ data[1] ^ data[2],
1160                                         data[3],data[4],data[5],data[6],
1161                                         data[3] ^ data[4] ^ data[5] ^ data[6],0x48,0x0f,0xe0,
1162                                         0xe1,0x10,0x12,0x00,
1163                                         0x03,0x00,0xfe,0x00,
1164                                         0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
1165                                         0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,
1166                                         0x00,0x00,0x00,0x00,
1167                                         0x00,0x00};
1168                                         AppendCrc14443a(blockdata+start, 16);
1169                                         EmSendCmdEx( blockdata+start, MAX_MIFARE_FRAME_SIZE, false);
1170                                 } else {
1171                                         uint8_t emdata[MAX_MIFARE_FRAME_SIZE];
1172                                         emlGetMemBt( emdata, start, 16);
1173                                         AppendCrc14443a(emdata, 16);
1174                                         EmSendCmdEx(emdata, sizeof(emdata), false);
1175                                 }
1176                                 p_response = NULL;
1177
1178                         } else {
1179                                 EmSendCmdEx(data+(4*block),16,false);
1180                                 // Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
1181                                 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1182                                 p_response = NULL;
1183                         }
1184                 } else if(receivedCmd[0] == 0x3A) {     // Received a FAST READ (ranged read) -- just returns all zeros.
1185
1186                                 uint8_t emdata[MAX_FRAME_SIZE];
1187                                 int start =  receivedCmd[1] * 4;
1188                                 int len   = (receivedCmd[2] - receivedCmd[1] + 1) * 4;
1189                                 emlGetMemBt( emdata, start, len);
1190                                 AppendCrc14443a(emdata, len);
1191                                 EmSendCmdEx(emdata, len+2, false);
1192                                 p_response = NULL;
1193
1194                 } else if(receivedCmd[0] == 0x3C && tagType == 7) {     // Received a READ SIGNATURE --
1195                                 // ECC data,  taken from a NTAG215 amiibo token. might work. LEN: 32, + 2 crc
1196                                 uint8_t data[] = {0x56,0x06,0xa6,0x4f,0x43,0x32,0x53,0x6f,
1197                                                                   0x43,0xda,0x45,0xd6,0x61,0x38,0xaa,0x1e,
1198                                                                   0xcf,0xd3,0x61,0x36,0xca,0x5f,0xbb,0x05,
1199                                                                   0xce,0x21,0x24,0x5b,0xa6,0x7a,0x79,0x07,
1200                                                                   0x00,0x00};
1201                                 AppendCrc14443a(data, sizeof(data)-2);
1202                                 EmSendCmdEx(data,sizeof(data),false);
1203                                 p_response = NULL;
1204                 } else if(receivedCmd[0] == 0x39 && tagType == 7) {     // Received a READ COUNTER --
1205                                 uint8_t data[] =  {0x00,0x00,0x00,0x14,0xa5};
1206                                 EmSendCmdEx(data,sizeof(data),false);
1207                                 p_response = NULL;
1208                 } else if(receivedCmd[0] == 0xA5 && tagType == 7) {     // Received a INC COUNTER --
1209                         // number of counter
1210                         //uint8_t counter = receivedCmd[1];
1211                         //uint32_t val = bytes_to_num(receivedCmd+2,4);
1212
1213                         // send ACK
1214                         uint8_t ack[] = {0x0a};
1215                         EmSendCmdEx(ack,sizeof(ack),false);
1216                         p_response = NULL;
1217
1218                 } else if(receivedCmd[0] == 0x3E && tagType == 7) {     // Received a CHECK_TEARING_EVENT --
1219                                 p_response = &responses[9];
1220                 } else if(receivedCmd[0] == 0x50) {     // Received a HALT
1221
1222                         if (tracing) {
1223                                 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1224                         }
1225                         p_response = NULL;
1226                 } else if(receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61) {   // Received an authentication request
1227
1228                         if ( tagType == 7 ) {   // IF NTAG /EV1  0x60 == GET_VERSION, not a authentication request.
1229                                 p_response = &responses[7];
1230                         } else {
1231                                 p_response = &responses[5]; order = 7;
1232                         }
1233                 } else if(receivedCmd[0] == 0xE0) {     // Received a RATS request
1234                         if (tagType == 1 || tagType == 2) {     // RATS not supported
1235                                 EmSend4bit(CARD_NACK_NA);
1236                                 p_response = NULL;
1237                         } else {
1238                                 p_response = &responses[6]; order = 70;
1239                         }
1240                 } else if (order == 7 && len == 8) { // Received {nr] and {ar} (part of authentication)
1241                         if (tracing) {
1242                                 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1243                         }
1244                         uint32_t nonce = bytes_to_num(response5,4);
1245                         uint32_t nr = bytes_to_num(receivedCmd,4);
1246                         uint32_t ar = bytes_to_num(receivedCmd+4,4);
1247                         //Dbprintf("Auth attempt {nonce}{nr}{ar}: %08x %08x %08x", nonce, nr, ar);
1248
1249                         if(flags & FLAG_NR_AR_ATTACK )
1250                         {
1251                                 if(ar_nr_collected < 2){
1252                                         // Avoid duplicates... probably not necessary, nr should vary.
1253                                         //if(ar_nr_responses[3] != nr){
1254                                                 ar_nr_responses[ar_nr_collected*5]   = 0;
1255                                                 ar_nr_responses[ar_nr_collected*5+1] = 0;
1256                                                 ar_nr_responses[ar_nr_collected*5+2] = nonce;
1257                                                 ar_nr_responses[ar_nr_collected*5+3] = nr;
1258                                                 ar_nr_responses[ar_nr_collected*5+4] = ar;
1259                                                 ar_nr_collected++;
1260                                         //}
1261                                 }
1262
1263                                 if(ar_nr_collected > 1 ) {
1264
1265                                         if (MF_DBGLEVEL >= 2) {
1266                                                         Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
1267                                                         Dbprintf("../tools/mfkey/mfkey32 %07x%08x %08x %08x %08x %08x %08x",
1268                                                                 ar_nr_responses[0], // UID1
1269                                                                 ar_nr_responses[1], // UID2
1270                                                                 ar_nr_responses[2], // NT
1271                                                                 ar_nr_responses[3], // AR1
1272                                                                 ar_nr_responses[4], // NR1
1273                                                                 ar_nr_responses[8], // AR2
1274                                                                 ar_nr_responses[9]  // NR2
1275                                                         );
1276                                                         Dbprintf("../tools/mfkey/mfkey32v2 %06x%08x %08x %08x %08x %08x %08x %08x",
1277                                                                 ar_nr_responses[0], // UID1
1278                                                                 ar_nr_responses[1], // UID2
1279                                                                 ar_nr_responses[2], // NT1
1280                                                                 ar_nr_responses[3], // AR1
1281                                                                 ar_nr_responses[4], // NR1
1282                                                                 ar_nr_responses[7], // NT2
1283                                                                 ar_nr_responses[8], // AR2
1284                                                                 ar_nr_responses[9]  // NR2
1285                                                                 );
1286                                         }
1287                                         uint8_t len = ar_nr_collected*5*4;
1288                                         cmd_send(CMD_ACK,CMD_SIMULATE_MIFARE_CARD,len,0,&ar_nr_responses,len);
1289                                         ar_nr_collected = 0;
1290                                         memset(ar_nr_responses, 0x00, len);
1291                                 }
1292                         }
1293                 } else if (receivedCmd[0] == 0x1a ) // ULC authentication
1294                 {
1295
1296                 }
1297                 else if (receivedCmd[0] == 0x1b) // NTAG / EV-1 authentication
1298                 {
1299                         if ( tagType == 7 ) {
1300                                 p_response =  &responses[8]; // PACK response
1301                                 uint32_t pwd = bytes_to_num(receivedCmd+1,4);
1302                                 Dbprintf("Auth attempt: %08x", pwd);
1303                         }
1304                 }
1305                 else {
1306                         // Check for ISO 14443A-4 compliant commands, look at left nibble
1307                         switch (receivedCmd[0]) {
1308                                 case 0x02:
1309                                 case 0x03: {  // IBlock (command no CID)
1310                                         dynamic_response_info.response[0] = receivedCmd[0];
1311                                         dynamic_response_info.response[1] = 0x90;
1312                                         dynamic_response_info.response[2] = 0x00;
1313                                         dynamic_response_info.response_n = 3;
1314                                 } break;
1315                                 case 0x0B:
1316                                 case 0x0A: { // IBlock (command CID)
1317                                   dynamic_response_info.response[0] = receivedCmd[0];
1318                                   dynamic_response_info.response[1] = 0x00;
1319                                   dynamic_response_info.response[2] = 0x90;
1320                                   dynamic_response_info.response[3] = 0x00;
1321                                   dynamic_response_info.response_n = 4;
1322                                 } break;
1323
1324                                 case 0x1A:
1325                                 case 0x1B: { // Chaining command
1326                                   dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1);
1327                                   dynamic_response_info.response_n = 2;
1328                                 } break;
1329
1330                                 case 0xaa:
1331                                 case 0xbb: {
1332                                   dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11;
1333                                   dynamic_response_info.response_n = 2;
1334                                 } break;
1335
1336                                 case 0xBA: { // ping / pong
1337                                         dynamic_response_info.response[0] = 0xAB;
1338                                         dynamic_response_info.response[1] = 0x00;
1339                                         dynamic_response_info.response_n = 2;
1340                                 } break;
1341
1342                                 case 0xCA:
1343                                 case 0xC2: { // Readers sends deselect command
1344                                         dynamic_response_info.response[0] = 0xCA;
1345                                         dynamic_response_info.response[1] = 0x00;
1346                                         dynamic_response_info.response_n = 2;
1347                                 } break;
1348
1349                                 default: {
1350                                         // Never seen this command before
1351                                         if (tracing) {
1352                                                 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1353                                         }
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                                         if (tracing) {
1372                                                 LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1373                                         }
1374                                         break;
1375                                 }
1376                                 p_response = &dynamic_response_info;
1377                         }
1378                 }
1379
1380                 // Count number of wakeups received after a halt
1381                 if(order == 6 && lastorder == 5) { happened++; }
1382
1383                 // Count number of other messages after a halt
1384                 if(order != 6 && lastorder == 5) { happened2++; }
1385
1386                 if(cmdsRecvd > 999) {
1387                         DbpString("1000 commands later...");
1388                         break;
1389                 }
1390                 cmdsRecvd++;
1391
1392                 if (p_response != NULL) {
1393                         EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52);
1394                         // do the tracing for the previous reader request and this tag answer:
1395                         uint8_t par[MAX_PARITY_SIZE];
1396                         GetParity(p_response->response, p_response->response_n, par);
1397
1398                         EmLogTrace(Uart.output,
1399                                                 Uart.len,
1400                                                 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1401                                                 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1402                                                 Uart.parity,
1403                                                 p_response->response,
1404                                                 p_response->response_n,
1405                                                 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1406                                                 (LastTimeProxToAirStart + p_response->ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1407                                                 par);
1408                 }
1409
1410                 if (!tracing) {
1411                         Dbprintf("Trace Full. Simulation stopped.");
1412                         break;
1413                 }
1414         }
1415
1416         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
1417         BigBuf_free_keep_EM();
1418         LED_A_OFF();
1419
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 // prepare a delayed transfer. This simply shifts ToSend[] by a number
1427 // of bits specified in the delay parameter.
1428 void PrepareDelayedTransfer(uint16_t delay)
1429 {
1430         uint8_t bitmask = 0;
1431         uint8_t bits_to_shift = 0;
1432         uint8_t bits_shifted = 0;
1433
1434         delay &= 0x07;
1435         if (delay) {
1436                 for (uint16_t i = 0; i < delay; i++) {
1437                         bitmask |= (0x01 << i);
1438                 }
1439                 ToSend[ToSendMax++] = 0x00;
1440                 for (uint16_t i = 0; i < ToSendMax; i++) {
1441                         bits_to_shift = ToSend[i] & bitmask;
1442                         ToSend[i] = ToSend[i] >> delay;
1443                         ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay));
1444                         bits_shifted = bits_to_shift;
1445                 }
1446         }
1447 }
1448
1449
1450 //-------------------------------------------------------------------------------------
1451 // Transmit the command (to the tag) that was placed in ToSend[].
1452 // Parameter timing:
1453 // if NULL: transfer at next possible time, taking into account
1454 //                      request guard time and frame delay time
1455 // if == 0:     transfer immediately and return time of transfer
1456 // if != 0: delay transfer until time specified
1457 //-------------------------------------------------------------------------------------
1458 static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing)
1459 {
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                 while(GetCountSspClk() < (*timing & 0xfffffff8));               // Delay transfer (multiple of 8 MF clock ticks)
1473                 LastTimeProxToAirStart = *timing;
1474         } else {
1475                 ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8);
1476                 while(GetCountSspClk() < ThisTransferTime);
1477                 LastTimeProxToAirStart = ThisTransferTime;
1478         }
1479
1480         // clear TXRDY
1481         AT91C_BASE_SSC->SSC_THR = SEC_Y;
1482
1483         uint16_t c = 0;
1484         for(;;) {
1485                 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1486                         AT91C_BASE_SSC->SSC_THR = cmd[c];
1487                         c++;
1488                         if(c >= len) {
1489                                 break;
1490                         }
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;
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         last = 0;
1513
1514         size_t bytecount = nbytes(bits);
1515         // Generate send structure for the data bits
1516         for (i = 0; i < bytecount; i++) {
1517                 // Get the current byte to send
1518                 b = cmd[i];
1519                 size_t bitsleft = MIN((bits-(i*8)),8);
1520
1521                 for (j = 0; j < bitsleft; j++) {
1522                         if (b & 1) {
1523                                 // Sequence X
1524                                 ToSend[++ToSendMax] = SEC_X;
1525                                 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1526                                 last = 1;
1527                         } else {
1528                                 if (last == 0) {
1529                                 // Sequence Z
1530                                 ToSend[++ToSendMax] = SEC_Z;
1531                                 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1532                                 } else {
1533                                         // Sequence Y
1534                                         ToSend[++ToSendMax] = SEC_Y;
1535                                         last = 0;
1536                                 }
1537                         }
1538                         b >>= 1;
1539                 }
1540
1541                 // Only transmit parity bit if we transmitted a complete byte
1542                 if (j == 8 && parity != NULL) {
1543                         // Get the parity bit
1544                         if (parity[i>>3] & (0x80 >> (i&0x0007))) {
1545                                 // Sequence X
1546                                 ToSend[++ToSendMax] = SEC_X;
1547                                 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1548                                 last = 1;
1549                         } else {
1550                                 if (last == 0) {
1551                                         // Sequence Z
1552                                         ToSend[++ToSendMax] = SEC_Z;
1553                                         LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1554                                 } else {
1555                                         // Sequence Y
1556                                         ToSend[++ToSendMax] = SEC_Y;
1557                                         last = 0;
1558                                 }
1559                         }
1560                 }
1561         }
1562
1563         // End of Communication: Logic 0 followed by Sequence Y
1564         if (last == 0) {
1565                 // Sequence Z
1566                 ToSend[++ToSendMax] = SEC_Z;
1567                 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1568         } else {
1569                 // Sequence Y
1570                 ToSend[++ToSendMax] = SEC_Y;
1571                 last = 0;
1572         }
1573         ToSend[++ToSendMax] = SEC_Y;
1574
1575         // Convert to length of command:
1576         ToSendMax++;
1577 }
1578
1579 //-----------------------------------------------------------------------------
1580 // Prepare reader command to send to FPGA
1581 //-----------------------------------------------------------------------------
1582 void CodeIso14443aAsReaderPar(const uint8_t *cmd, uint16_t len, const uint8_t *parity)
1583 {
1584   CodeIso14443aBitsAsReaderPar(cmd, len*8, 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;
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];
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];
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];
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         if (tracing) {
1781                 // we cannot exactly measure the end and start of a received command from reader. However we know that the delay from
1782                 // end of the received command to start of the tag's (simulated by us) answer is n*128+20 or n*128+84 resp.
1783                 // with n >= 9. The start of the tags answer can be measured and therefore the end of the received command be calculated:
1784                 uint16_t reader_modlen = reader_EndTime - reader_StartTime;
1785                 uint16_t approx_fdt = tag_StartTime - reader_EndTime;
1786                 uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20;
1787                 reader_EndTime = tag_StartTime - exact_fdt;
1788                 reader_StartTime = reader_EndTime - reader_modlen;
1789                 if (!LogTrace(reader_data, reader_len, reader_StartTime, reader_EndTime, reader_Parity, TRUE)) {
1790                         return FALSE;
1791                 } else return(!LogTrace(tag_data, tag_len, tag_StartTime, tag_EndTime, tag_Parity, FALSE));
1792         } else {
1793                 return TRUE;
1794         }
1795 }
1796
1797 //-----------------------------------------------------------------------------
1798 // Wait a certain time for tag response
1799 //  If a response is captured return TRUE
1800 //  If it takes too long return FALSE
1801 //-----------------------------------------------------------------------------
1802 static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receivedResponsePar, uint16_t offset)
1803 {
1804         uint32_t c = 0x00;
1805
1806         // Set FPGA mode to "reader listen mode", no modulation (listen
1807         // only, since we are receiving, not transmitting).
1808         // Signal field is on with the appropriate LED
1809         LED_D_ON();
1810         FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
1811
1812         // Now get the answer from the card
1813         DemodInit(receivedResponse, receivedResponsePar);
1814
1815         // clear RXRDY:
1816     uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1817
1818         for(;;) {
1819                 WDT_HIT();
1820
1821                 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1822                         b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1823                         if(ManchesterDecoding(b, offset, 0)) {
1824                                 NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD);
1825                                 return TRUE;
1826                         } else if (c++ > iso14a_timeout && Demod.state == DEMOD_UNSYNCD) {
1827                                 return FALSE;
1828                         }
1829                 }
1830         }
1831 }
1832
1833 void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t *timing)
1834 {
1835         CodeIso14443aBitsAsReaderPar(frame, bits, par);
1836
1837         // Send command to tag
1838         TransmitFor14443a(ToSend, ToSendMax, timing);
1839         if(trigger)
1840                 LED_A_ON();
1841
1842         // Log reader command in trace buffer
1843         if (tracing) {
1844                 LogTrace(frame, nbytes(bits), LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_READER, (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_READER, par, TRUE);
1845         }
1846 }
1847
1848 void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *timing)
1849 {
1850   ReaderTransmitBitsPar(frame, len*8, par, timing);
1851 }
1852
1853 void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing)
1854 {
1855   // Generate parity and redirect
1856   uint8_t par[MAX_PARITY_SIZE];
1857   GetParity(frame, len/8, 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];
1865   GetParity(frame, len, par);
1866   ReaderTransmitBitsPar(frame, len*8, par, timing);
1867 }
1868
1869 int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset, uint8_t *parity)
1870 {
1871         if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, offset)) return FALSE;
1872         if (tracing) {
1873                 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1874         }
1875         return Demod.len;
1876 }
1877
1878 int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity)
1879 {
1880         if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, 0)) return FALSE;
1881         if (tracing) {
1882                 LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1883         }
1884         return Demod.len;
1885 }
1886
1887 /* performs iso14443a anticollision procedure
1888  * fills the uid pointer unless NULL
1889  * fills resp_data unless NULL */
1890 int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, uint32_t *cuid_ptr) {
1891         uint8_t wupa[]       = { 0x52 };  // 0x26 - REQA  0x52 - WAKE-UP
1892         uint8_t sel_all[]    = { 0x93,0x20 };
1893         uint8_t sel_uid[]    = { 0x93,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
1894         uint8_t rats[]       = { 0xE0,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
1895         uint8_t resp[MAX_FRAME_SIZE]; // theoretically. A usual RATS will be much smaller
1896         uint8_t resp_par[MAX_PARITY_SIZE];
1897         byte_t uid_resp[4];
1898         size_t uid_resp_len;
1899
1900         uint8_t sak = 0x04; // cascade uid
1901         int cascade_level = 0;
1902         int len;
1903
1904         // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
1905     ReaderTransmitBitsPar(wupa,7,0, NULL);
1906
1907         // Receive the ATQA
1908         if(!ReaderReceive(resp, resp_par)) return 0;
1909
1910         if(p_hi14a_card) {
1911                 memcpy(p_hi14a_card->atqa, resp, 2);
1912                 p_hi14a_card->uidlen = 0;
1913                 memset(p_hi14a_card->uid,0,10);
1914         }
1915
1916         // clear uid
1917         if (uid_ptr) {
1918                 memset(uid_ptr,0,10);
1919         }
1920
1921         // check for proprietary anticollision:
1922         if ((resp[0] & 0x1F) == 0) {
1923                 return 3;
1924         }
1925
1926         // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
1927         // which case we need to make a cascade 2 request and select - this is a long UID
1928         // While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
1929         for(; sak & 0x04; cascade_level++) {
1930                 // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
1931                 sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
1932
1933                 // SELECT_ALL
1934                 ReaderTransmit(sel_all, sizeof(sel_all), NULL);
1935                 if (!ReaderReceive(resp, resp_par)) return 0;
1936
1937                 if (Demod.collisionPos) {                       // we had a collision and need to construct the UID bit by bit
1938                         memset(uid_resp, 0, 4);
1939                         uint16_t uid_resp_bits = 0;
1940                         uint16_t collision_answer_offset = 0;
1941                         // anti-collision-loop:
1942                         while (Demod.collisionPos) {
1943                                 Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos);
1944                                 for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) {      // add valid UID bits before collision point
1945                                         uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01;
1946                                         uid_resp[uid_resp_bits / 8] |= UIDbit << (uid_resp_bits % 8);
1947                                 }
1948                                 uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8);                                  // next time select the card(s) with a 1 in the collision position
1949                                 uid_resp_bits++;
1950                                 // construct anticollosion command:
1951                                 sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07);     // length of data in bytes and bits
1952                                 for (uint16_t i = 0; i <= uid_resp_bits/8; i++) {
1953                                         sel_uid[2+i] = uid_resp[i];
1954                                 }
1955                                 collision_answer_offset = uid_resp_bits%8;
1956                                 ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL);
1957                                 if (!ReaderReceiveOffset(resp, collision_answer_offset, resp_par)) return 0;
1958                         }
1959                         // finally, add the last bits and BCC of the UID
1960                         for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) {
1961                                 uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01;
1962                                 uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8);
1963                         }
1964
1965                 } else {                // no collision, use the response to SELECT_ALL as current uid
1966                         memcpy(uid_resp, resp, 4);
1967                 }
1968                 uid_resp_len = 4;
1969
1970                 // calculate crypto UID. Always use last 4 Bytes.
1971                 if(cuid_ptr) {
1972                         *cuid_ptr = bytes_to_num(uid_resp, 4);
1973                 }
1974
1975                 // Construct SELECT UID command
1976                 sel_uid[1] = 0x70;                                                                                                      // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC)
1977                 memcpy(sel_uid+2, uid_resp, 4);                                                                         // the UID
1978                 sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5];         // calculate and add BCC
1979                 AppendCrc14443a(sel_uid, 7);                                                                            // calculate and add CRC
1980                 ReaderTransmit(sel_uid, sizeof(sel_uid), NULL);
1981
1982                 // Receive the SAK
1983                 if (!ReaderReceive(resp, resp_par)) return 0;
1984                 sak = resp[0];
1985
1986     // Test if more parts of the uid are coming
1987                 if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) {
1988                         // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of:
1989                         // http://www.nxp.com/documents/application_note/AN10927.pdf
1990                         uid_resp[0] = uid_resp[1];
1991                         uid_resp[1] = uid_resp[2];
1992                         uid_resp[2] = uid_resp[3];
1993
1994                         uid_resp_len = 3;
1995                 }
1996
1997                 if(uid_ptr) {
1998                         memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len);
1999                 }
2000
2001                 if(p_hi14a_card) {
2002                         memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
2003                         p_hi14a_card->uidlen += uid_resp_len;
2004                 }
2005         }
2006
2007         if(p_hi14a_card) {
2008                 p_hi14a_card->sak = sak;
2009                 p_hi14a_card->ats_len = 0;
2010         }
2011
2012         // non iso14443a compliant tag
2013         if( (sak & 0x20) == 0) return 2;
2014
2015         // Request for answer to select
2016         AppendCrc14443a(rats, 2);
2017         ReaderTransmit(rats, sizeof(rats), NULL);
2018
2019         if (!(len = ReaderReceive(resp, resp_par))) return 0;
2020
2021
2022         if(p_hi14a_card) {
2023                 memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
2024                 p_hi14a_card->ats_len = len;
2025         }
2026
2027         // reset the PCB block number
2028         iso14_pcb_blocknum = 0;
2029
2030         // set default timeout based on ATS
2031         iso14a_set_ATS_timeout(resp);
2032
2033         return 1;
2034 }
2035
2036 void iso14443a_setup(uint8_t fpga_minor_mode) {
2037         FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
2038         // Set up the synchronous serial port
2039         FpgaSetupSsc();
2040         // connect Demodulated Signal to ADC:
2041         SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
2042
2043         // Signal field is on with the appropriate LED
2044         if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD
2045                 || fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN) {
2046                 LED_D_ON();
2047         } else {
2048                 LED_D_OFF();
2049         }
2050         FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode);
2051
2052         // Start the timer
2053         StartCountSspClk();
2054
2055         DemodReset();
2056         UartReset();
2057         NextTransferTime = 2*DELAY_ARM2AIR_AS_READER;
2058         iso14a_set_timeout(10*106); // 10ms default
2059 }
2060
2061 int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data) {
2062         uint8_t parity[MAX_PARITY_SIZE];
2063         uint8_t real_cmd[cmd_len+4];
2064         real_cmd[0] = 0x0a; //I-Block
2065         // put block number into the PCB
2066         real_cmd[0] |= iso14_pcb_blocknum;
2067         real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards
2068         memcpy(real_cmd+2, cmd, cmd_len);
2069         AppendCrc14443a(real_cmd,cmd_len+2);
2070
2071         ReaderTransmit(real_cmd, cmd_len+4, NULL);
2072         size_t len = ReaderReceive(data, parity);
2073         uint8_t *data_bytes = (uint8_t *) data;
2074         if (!len)
2075                 return 0; //DATA LINK ERROR
2076         // if we received an I- or R(ACK)-Block with a block number equal to the
2077         // current block number, toggle the current block number
2078         else if (len >= 4 // PCB+CID+CRC = 4 bytes
2079                  && ((data_bytes[0] & 0xC0) == 0 // I-Block
2080                      || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0
2081                  && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers
2082         {
2083                 iso14_pcb_blocknum ^= 1;
2084         }
2085
2086         return len;
2087 }
2088
2089 //-----------------------------------------------------------------------------
2090 // Read an ISO 14443a tag. Send out commands and store answers.
2091 //
2092 //-----------------------------------------------------------------------------
2093 void ReaderIso14443a(UsbCommand *c)
2094 {
2095         iso14a_command_t param = c->arg[0];
2096         uint8_t *cmd = c->d.asBytes;
2097         size_t len = c->arg[1] & 0xffff;
2098         size_t lenbits = c->arg[1] >> 16;
2099         uint32_t timeout = c->arg[2];
2100         uint32_t arg0 = 0;
2101         byte_t buf[USB_CMD_DATA_SIZE];
2102         uint8_t par[MAX_PARITY_SIZE];
2103
2104         if(param & ISO14A_CONNECT) {
2105                 clear_trace();
2106         }
2107
2108         set_tracing(TRUE);
2109
2110         if(param & ISO14A_REQUEST_TRIGGER) {
2111                 iso14a_set_trigger(TRUE);
2112         }
2113
2114         if(param & ISO14A_CONNECT) {
2115                 iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN);
2116                 if(!(param & ISO14A_NO_SELECT)) {
2117                         iso14a_card_select_t *card = (iso14a_card_select_t*)buf;
2118                         arg0 = iso14443a_select_card(NULL,card,NULL);
2119                         cmd_send(CMD_ACK,arg0,card->uidlen,0,buf,sizeof(iso14a_card_select_t));
2120                 }
2121         }
2122
2123         if(param & ISO14A_SET_TIMEOUT) {
2124                 iso14a_set_timeout(timeout);
2125         }
2126
2127         if(param & ISO14A_APDU) {
2128                 arg0 = iso14_apdu(cmd, len, buf);
2129                 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
2130         }
2131
2132         if(param & ISO14A_RAW) {
2133                 if(param & ISO14A_APPEND_CRC) {
2134                         if(param & ISO14A_TOPAZMODE) {
2135                                 AppendCrc14443b(cmd,len);
2136                         } else {
2137                                 AppendCrc14443a(cmd,len);
2138                         }
2139                         len += 2;
2140                         if (lenbits) lenbits += 16;
2141                 }
2142                 if(lenbits>0) {                         // want to send a specific number of bits (e.g. short commands)
2143                         if(param & ISO14A_TOPAZMODE) {
2144                                 int bits_to_send = lenbits;
2145                                 uint16_t i = 0;
2146                                 ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 7), NULL, NULL);             // first byte is always short (7bits) and no parity
2147                                 bits_to_send -= 7;
2148                                 while (bits_to_send > 0) {
2149                                         ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 8), NULL, NULL);     // following bytes are 8 bit and no parity
2150                                         bits_to_send -= 8;
2151                                 }
2152                         } else {
2153                         GetParity(cmd, lenbits/8, par);
2154                                 ReaderTransmitBitsPar(cmd, lenbits, par, NULL);                                                 // bytes are 8 bit with odd parity
2155                         }
2156                 } else {                                        // want to send complete bytes only
2157                         if(param & ISO14A_TOPAZMODE) {
2158                                 uint16_t i = 0;
2159                                 ReaderTransmitBitsPar(&cmd[i++], 7, NULL, NULL);                                                // first byte: 7 bits, no paritiy
2160                                 while (i < len) {
2161                                         ReaderTransmitBitsPar(&cmd[i++], 8, NULL, NULL);                                        // following bytes: 8 bits, no paritiy
2162                                 }
2163                 } else {
2164                                 ReaderTransmit(cmd,len, NULL);                                                                                  // 8 bits, odd parity
2165                         }
2166                 }
2167                 arg0 = ReaderReceive(buf, par);
2168                 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
2169         }
2170
2171         if(param & ISO14A_REQUEST_TRIGGER) {
2172                 iso14a_set_trigger(FALSE);
2173         }
2174
2175         if(param & ISO14A_NO_DISCONNECT) {
2176                 return;
2177         }
2178
2179         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2180         LEDsoff();
2181 }
2182
2183
2184 // Determine the distance between two nonces.
2185 // Assume that the difference is small, but we don't know which is first.
2186 // Therefore try in alternating directions.
2187 int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
2188
2189         uint16_t i;
2190         uint32_t nttmp1, nttmp2;
2191
2192         if (nt1 == nt2) return 0;
2193
2194         nttmp1 = nt1;
2195         nttmp2 = nt2;
2196
2197         for (i = 1; i < 32768; i++) {
2198                 nttmp1 = prng_successor(nttmp1, 1);
2199                 if (nttmp1 == nt2) return i;
2200                 nttmp2 = prng_successor(nttmp2, 1);
2201                         if (nttmp2 == nt1) return -i;
2202                 }
2203
2204         return(-99999); // either nt1 or nt2 are invalid nonces
2205 }
2206
2207
2208 //-----------------------------------------------------------------------------
2209 // Recover several bits of the cypher stream. This implements (first stages of)
2210 // the algorithm described in "The Dark Side of Security by Obscurity and
2211 // Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime"
2212 // (article by Nicolas T. Courtois, 2009)
2213 //-----------------------------------------------------------------------------
2214 void ReaderMifare(bool first_try)
2215 {
2216         // Mifare AUTH
2217         uint8_t mf_auth[]    = { 0x60,0x00,0xf5,0x7b };
2218         uint8_t mf_nr_ar[]   = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
2219         static uint8_t mf_nr_ar3;
2220
2221         uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE];
2222         uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE];
2223
2224         if (first_try) {
2225                 iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
2226         }
2227
2228         // free eventually allocated BigBuf memory. We want all for tracing.
2229         BigBuf_free();
2230
2231         clear_trace();
2232         set_tracing(TRUE);
2233
2234         byte_t nt_diff = 0;
2235         uint8_t par[1] = {0};   // maximum 8 Bytes to be sent here, 1 byte parity is therefore enough
2236         static byte_t par_low = 0;
2237         bool led_on = TRUE;
2238         uint8_t uid[10]  ={0};
2239         uint32_t cuid;
2240
2241         uint32_t nt = 0;
2242         uint32_t previous_nt = 0;
2243         static uint32_t nt_attacked = 0;
2244         byte_t par_list[8] = {0x00};
2245         byte_t ks_list[8] = {0x00};
2246
2247         static uint32_t sync_time = 0;
2248         static uint32_t sync_cycles = 0;
2249         int catch_up_cycles = 0;
2250         int last_catch_up = 0;
2251         uint16_t consecutive_resyncs = 0;
2252         int isOK = 0;
2253
2254         if (first_try) {
2255                 mf_nr_ar3 = 0;
2256                 sync_time = GetCountSspClk() & 0xfffffff8;
2257                 sync_cycles = 65536;                                                                    // theory: Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
2258                 nt_attacked = 0;
2259                 nt = 0;
2260                 par[0] = 0;
2261         }
2262         else {
2263                 // we were unsuccessful on a previous call. Try another READER nonce (first 3 parity bits remain the same)
2264                 mf_nr_ar3++;
2265                 mf_nr_ar[3] = mf_nr_ar3;
2266                 par[0] = par_low;
2267         }
2268
2269         LED_A_ON();
2270         LED_B_OFF();
2271         LED_C_OFF();
2272
2273
2274         #define DARKSIDE_MAX_TRIES      32              // number of tries to sync on PRNG cycle. Then give up.
2275         uint16_t unsuccessfull_tries = 0;
2276
2277         for(uint16_t i = 0; TRUE; i++) {
2278
2279                 LED_C_ON();
2280                 WDT_HIT();
2281
2282                 // Test if the action was cancelled
2283                 if(BUTTON_PRESS()) {
2284                         isOK = -1;
2285                         break;
2286                 }
2287
2288                 if(!iso14443a_select_card(uid, NULL, &cuid)) {
2289                         if (MF_DBGLEVEL >= 1)   Dbprintf("Mifare: Can't select card");
2290                         continue;
2291                 }
2292
2293                 sync_time = (sync_time & 0xfffffff8) + sync_cycles + catch_up_cycles;
2294                 catch_up_cycles = 0;
2295
2296                 // if we missed the sync time already, advance to the next nonce repeat
2297                 while(GetCountSspClk() > sync_time) {
2298                         sync_time = (sync_time & 0xfffffff8) + sync_cycles;
2299                 }
2300
2301                 // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked)
2302                 ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
2303
2304                 // Receive the (4 Byte) "random" nonce
2305                 if (!ReaderReceive(receivedAnswer, receivedAnswerPar)) {
2306                         if (MF_DBGLEVEL >= 1)   Dbprintf("Mifare: Couldn't receive tag nonce");
2307                         continue;
2308                   }
2309
2310                 previous_nt = nt;
2311                 nt = bytes_to_num(receivedAnswer, 4);
2312
2313                 // Transmit reader nonce with fake par
2314                 ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
2315
2316                 if (first_try && previous_nt && !nt_attacked) { // we didn't calibrate our clock yet
2317                         int nt_distance = dist_nt(previous_nt, nt);
2318                         if (nt_distance == 0) {
2319                                 nt_attacked = nt;
2320                         }
2321                         else {
2322                                 if (nt_distance == -99999) { // invalid nonce received
2323                                         unsuccessfull_tries++;
2324                                         if (!nt_attacked && unsuccessfull_tries > DARKSIDE_MAX_TRIES) {
2325                                                 isOK = -3;              // Card has an unpredictable PRNG. Give up
2326                                                 break;
2327                                         } else {
2328                                                 continue;               // continue trying...
2329                                         }
2330                                 }
2331                                 sync_cycles = (sync_cycles - nt_distance);
2332                                 if (MF_DBGLEVEL >= 3) Dbprintf("calibrating in cycle %d. nt_distance=%d, Sync_cycles: %d\n", i, nt_distance, sync_cycles);
2333                                 continue;
2334                         }
2335                 }
2336
2337                 if ((nt != nt_attacked) && nt_attacked) {       // we somehow lost sync. Try to catch up again...
2338                         catch_up_cycles = -dist_nt(nt_attacked, nt);
2339                         if (catch_up_cycles == 99999) {                 // invalid nonce received. Don't resync on that one.
2340                                 catch_up_cycles = 0;
2341                                 continue;
2342                         }
2343                         if (catch_up_cycles == last_catch_up) {
2344                                 consecutive_resyncs++;
2345                         }
2346                         else {
2347                                 last_catch_up = catch_up_cycles;
2348                             consecutive_resyncs = 0;
2349                         }
2350                         if (consecutive_resyncs < 3) {
2351                                 if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d. nt_distance=%d. Consecutive Resyncs = %d. Trying one time catch up...\n", i, -catch_up_cycles, consecutive_resyncs);
2352                         }
2353                         else {
2354                                 sync_cycles = sync_cycles + catch_up_cycles;
2355                                 if (MF_DBGLEVEL >= 3) Dbprintf("Lost sync in cycle %d for the fourth time consecutively (nt_distance = %d). Adjusting sync_cycles to %d.\n", i, -catch_up_cycles, sync_cycles);
2356                         }
2357                         continue;
2358                 }
2359
2360                 consecutive_resyncs = 0;
2361
2362                 // Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
2363                 if (ReaderReceive(receivedAnswer, receivedAnswerPar))
2364                 {
2365                         catch_up_cycles = 8;    // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
2366
2367                         if (nt_diff == 0)
2368                         {
2369                                 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
2370                         }
2371
2372                         led_on = !led_on;
2373                         if(led_on) LED_B_ON(); else LED_B_OFF();
2374
2375                         par_list[nt_diff] = SwapBits(par[0], 8);
2376                         ks_list[nt_diff] = receivedAnswer[0] ^ 0x05;
2377
2378                         // Test if the information is complete
2379                         if (nt_diff == 0x07) {
2380                                 isOK = 1;
2381                                 break;
2382                         }
2383
2384                         nt_diff = (nt_diff + 1) & 0x07;
2385                         mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
2386                         par[0] = par_low;
2387                 } else {
2388                         if (nt_diff == 0 && first_try)
2389                         {
2390                                 par[0]++;
2391                                 if (par[0] == 0x00) {           // tried all 256 possible parities without success. Card doesn't send NACK.
2392                                         isOK = -2;
2393                                         break;
2394                                 }
2395                         } else {
2396                                 par[0] = ((par[0] & 0x1F) + 1) | par_low;
2397                         }
2398                 }
2399         }
2400
2401
2402         mf_nr_ar[3] &= 0x1F;
2403
2404         byte_t buf[28] = {0x00};
2405
2406         memcpy(buf + 0,  uid, 4);
2407         num_to_bytes(nt, 4, buf + 4);
2408         memcpy(buf + 8,  par_list, 8);
2409         memcpy(buf + 16, ks_list, 8);
2410         memcpy(buf + 24, mf_nr_ar, 4);
2411
2412         cmd_send(CMD_ACK,isOK,0,0,buf,28);
2413
2414         // Thats it...
2415         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2416         LEDsoff();
2417
2418         set_tracing(FALSE);
2419 }
2420
2421
2422  /*
2423   *MIFARE 1K simulate.
2424   *
2425   *@param flags :
2426   *     FLAG_INTERACTIVE - In interactive mode, we are expected to finish the operation with an ACK
2427   * 4B_FLAG_UID_IN_DATA - means that there is a 4-byte UID in the data-section, we're expected to use that
2428   * 7B_FLAG_UID_IN_DATA - means that there is a 7-byte UID in the data-section, we're expected to use that
2429   *     FLAG_NR_AR_ATTACK  - means we should collect NR_AR responses for bruteforcing later
2430   *@param exitAfterNReads, exit simulation after n blocks have been read, 0 is inifite
2431   */
2432 void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *datain)
2433 {
2434         int cardSTATE = MFEMUL_NOFIELD;
2435         int _7BUID = 0;
2436         int vHf = 0;    // in mV
2437         int res;
2438         uint32_t selTimer = 0;
2439         uint32_t authTimer = 0;
2440         uint16_t len = 0;
2441         uint8_t cardWRBL = 0;
2442         uint8_t cardAUTHSC = 0;
2443         uint8_t cardAUTHKEY = 0xff;  // no authentication
2444 //      uint32_t cardRr = 0;
2445         uint32_t cuid = 0;
2446         //uint32_t rn_enc = 0;
2447         uint32_t ans = 0;
2448         uint32_t cardINTREG = 0;
2449         uint8_t cardINTBLOCK = 0;
2450         struct Crypto1State mpcs = {0, 0};
2451         struct Crypto1State *pcs;
2452         pcs = &mpcs;
2453         uint32_t numReads = 0;//Counts numer of times reader read a block
2454         uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE];
2455         uint8_t receivedCmd_par[MAX_MIFARE_PARITY_SIZE];
2456         uint8_t response[MAX_MIFARE_FRAME_SIZE];
2457         uint8_t response_par[MAX_MIFARE_PARITY_SIZE];
2458
2459         uint8_t rATQA[] = {0x04, 0x00}; // Mifare classic 1k 4BUID
2460         uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2461         uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62}; // !!!
2462         //uint8_t rSAK[] = {0x08, 0xb6, 0xdd}; // Mifare Classic
2463         uint8_t rSAK[] = {0x09, 0x3f, 0xcc };  // Mifare Mini
2464         uint8_t rSAK1[] = {0x04, 0xda, 0x17};
2465
2466         uint8_t rAUTH_NT[] = {0x01, 0x01, 0x01, 0x01};
2467         uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
2468
2469         //Here, we collect UID,NT,AR,NR,UID2,NT2,AR2,NR2
2470         // This can be used in a reader-only attack.
2471         // (it can also be retrieved via 'hf 14a list', but hey...
2472         uint32_t ar_nr_responses[] = {0,0,0,0,0,0,0,0,0,0};
2473         uint8_t ar_nr_collected = 0;
2474
2475         // Authenticate response - nonce
2476         uint32_t nonce = bytes_to_num(rAUTH_NT, 4);
2477
2478         //-- Determine the UID
2479         // Can be set from emulator memory, incoming data
2480         // and can be 7 or 4 bytes long
2481         if (flags & FLAG_4B_UID_IN_DATA)
2482         {
2483                 // 4B uid comes from data-portion of packet
2484                 memcpy(rUIDBCC1,datain,4);
2485                 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2486
2487         } else if (flags & FLAG_7B_UID_IN_DATA) {
2488                 // 7B uid comes from data-portion of packet
2489                 memcpy(&rUIDBCC1[1],datain,3);
2490                 memcpy(rUIDBCC2, datain+3, 4);
2491                 _7BUID = true;
2492         } else {
2493                 // get UID from emul memory
2494                 emlGetMemBt(receivedCmd, 7, 1);
2495                 _7BUID = !(receivedCmd[0] == 0x00);
2496                 if (!_7BUID) {                     // ---------- 4BUID
2497                         emlGetMemBt(rUIDBCC1, 0, 4);
2498                 } else {                           // ---------- 7BUID
2499                         emlGetMemBt(&rUIDBCC1[1], 0, 3);
2500                         emlGetMemBt(rUIDBCC2, 3, 4);
2501                 }
2502         }
2503
2504         // save uid.
2505         ar_nr_responses[0*5]   = bytes_to_num(rUIDBCC1+1, 3);
2506         if ( _7BUID )
2507                 ar_nr_responses[0*5+1] = bytes_to_num(rUIDBCC2, 4);
2508
2509         /*
2510          * Regardless of what method was used to set the UID, set fifth byte and modify
2511          * the ATQA for 4 or 7-byte UID
2512          */
2513         rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2514         if (_7BUID) {
2515                 rATQA[0] = 0x44;
2516                 rUIDBCC1[0] = 0x88;
2517                 rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2518                 rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
2519         }
2520
2521         if (MF_DBGLEVEL >= 1)   {
2522                 if (!_7BUID) {
2523                         Dbprintf("4B UID: %02x%02x%02x%02x",
2524                                 rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3]);
2525                 } else {
2526                         Dbprintf("7B UID: (%02x)%02x%02x%02x%02x%02x%02x%02x",
2527                                 rUIDBCC1[0], rUIDBCC1[1], rUIDBCC1[2], rUIDBCC1[3],
2528                                 rUIDBCC2[0], rUIDBCC2[1] ,rUIDBCC2[2], rUIDBCC2[3]);
2529                 }
2530         }
2531
2532         // We need to listen to the high-frequency, peak-detected path.
2533         iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
2534
2535         // free eventually allocated BigBuf memory but keep Emulator Memory
2536         BigBuf_free_keep_EM();
2537
2538         // clear trace
2539         clear_trace();
2540         set_tracing(TRUE);
2541
2542
2543         bool finished = FALSE;
2544         while (!BUTTON_PRESS() && !finished) {
2545                 WDT_HIT();
2546
2547                 // find reader field
2548                 if (cardSTATE == MFEMUL_NOFIELD) {
2549                         vHf = (MAX_ADC_HF_VOLTAGE * AvgAdc(ADC_CHAN_HF)) >> 10;
2550                         if (vHf > MF_MINFIELDV) {
2551                                 cardSTATE_TO_IDLE();
2552                                 LED_A_ON();
2553                         }
2554                 }
2555                 if(cardSTATE == MFEMUL_NOFIELD) continue;
2556
2557                 //Now, get data
2558                 res = EmGetCmd(receivedCmd, &len, receivedCmd_par);
2559                 if (res == 2) { //Field is off!
2560                         cardSTATE = MFEMUL_NOFIELD;
2561                         LEDsoff();
2562                         continue;
2563                 } else if (res == 1) {
2564                         break;  //return value 1 means button press
2565                 }
2566
2567                 // REQ or WUP request in ANY state and WUP in HALTED state
2568                 if (len == 1 && ((receivedCmd[0] == 0x26 && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == 0x52)) {
2569                         selTimer = GetTickCount();
2570                         EmSendCmdEx(rATQA, sizeof(rATQA), (receivedCmd[0] == 0x52));
2571                         cardSTATE = MFEMUL_SELECT1;
2572
2573                         // init crypto block
2574                         LED_B_OFF();
2575                         LED_C_OFF();
2576                         crypto1_destroy(pcs);
2577                         cardAUTHKEY = 0xff;
2578                         continue;
2579                 }
2580
2581                 switch (cardSTATE) {
2582                         case MFEMUL_NOFIELD:
2583                         case MFEMUL_HALTED:
2584                         case MFEMUL_IDLE:{
2585                                 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2586                                 break;
2587                         }
2588                         case MFEMUL_SELECT1:{
2589                                 // select all
2590                                 if (len == 2 && (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x20)) {
2591                                         if (MF_DBGLEVEL >= 4)   Dbprintf("SELECT ALL received");
2592                                         EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1));
2593                                         break;
2594                                 }
2595
2596                                 if (MF_DBGLEVEL >= 4 && len == 9 && receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 )
2597                                 {
2598                                         Dbprintf("SELECT %02x%02x%02x%02x received",receivedCmd[2],receivedCmd[3],receivedCmd[4],receivedCmd[5]);
2599                                 }
2600                                 // select card
2601                                 if (len == 9 &&
2602                                                 (receivedCmd[0] == 0x93 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
2603                                         EmSendCmd(_7BUID?rSAK1:rSAK, _7BUID?sizeof(rSAK1):sizeof(rSAK));
2604                                         cuid = bytes_to_num(rUIDBCC1, 4);
2605                                         if (!_7BUID) {
2606                                                 cardSTATE = MFEMUL_WORK;
2607                                                 LED_B_ON();
2608                                                 if (MF_DBGLEVEL >= 4)   Dbprintf("--> WORK. anticol1 time: %d", GetTickCount() - selTimer);
2609                                                 break;
2610                                         } else {
2611                                                 cardSTATE = MFEMUL_SELECT2;
2612                                         }
2613                                 }
2614                                 break;
2615                         }
2616                         case MFEMUL_AUTH1:{
2617                                 if( len != 8)
2618                                 {
2619                                         cardSTATE_TO_IDLE();
2620                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2621                                         break;
2622                                 }
2623
2624                                 uint32_t ar = bytes_to_num(receivedCmd, 4);
2625                                 uint32_t nr = bytes_to_num(&receivedCmd[4], 4);
2626
2627                                 //Collect AR/NR
2628                                 //if(ar_nr_collected < 2 && cardAUTHSC == 2){
2629                                 if(ar_nr_collected < 2){
2630                                         if(ar_nr_responses[2] != ar)
2631                                         {// Avoid duplicates... probably not necessary, ar should vary.
2632                                                 //ar_nr_responses[ar_nr_collected*5]   = 0;
2633                                                 //ar_nr_responses[ar_nr_collected*5+1] = 0;
2634                                                 ar_nr_responses[ar_nr_collected*5+2] = nonce;
2635                                                 ar_nr_responses[ar_nr_collected*5+3] = nr;
2636                                                 ar_nr_responses[ar_nr_collected*5+4] = ar;
2637                                                 ar_nr_collected++;
2638                                         }
2639                                         // Interactive mode flag, means we need to send ACK
2640                                         if(flags & FLAG_INTERACTIVE && ar_nr_collected == 2)
2641                                         {
2642                                                 finished = true;
2643                                         }
2644                                 }
2645
2646                                 // --- crypto
2647                                 //crypto1_word(pcs, ar , 1);
2648                                 //cardRr = nr ^ crypto1_word(pcs, 0, 0);
2649
2650                                 //test if auth OK
2651                                 //if (cardRr != prng_successor(nonce, 64)){
2652
2653                                         //if (MF_DBGLEVEL >= 4) Dbprintf("AUTH FAILED for sector %d with key %c. cardRr=%08x, succ=%08x",
2654                                         //      cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
2655                                         //              cardRr, prng_successor(nonce, 64));
2656                                         // Shouldn't we respond anything here?
2657                                         // Right now, we don't nack or anything, which causes the
2658                                         // reader to do a WUPA after a while. /Martin
2659                                         // -- which is the correct response. /piwi
2660                                         //cardSTATE_TO_IDLE();
2661                                         //LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2662                                         //break;
2663                                 //}
2664
2665                                 ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0);
2666
2667                                 num_to_bytes(ans, 4, rAUTH_AT);
2668                                 // --- crypto
2669                                 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2670                                 LED_C_ON();
2671                                 cardSTATE = MFEMUL_WORK;
2672                                 if (MF_DBGLEVEL >= 4)   Dbprintf("AUTH COMPLETED for sector %d with key %c. time=%d",
2673                                         cardAUTHSC, cardAUTHKEY == 0 ? 'A' : 'B',
2674                                         GetTickCount() - authTimer);
2675                                 break;
2676                         }
2677                         case MFEMUL_SELECT2:{
2678                                 if (!len) {
2679                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2680                                         break;
2681                                 }
2682                                 if (len == 2 && (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x20)) {
2683                                         EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2));
2684                                         break;
2685                                 }
2686
2687                                 // select 2 card
2688                                 if (len == 9 &&
2689                                                 (receivedCmd[0] == 0x95 && receivedCmd[1] == 0x70 && memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0)) {
2690                                         EmSendCmd(rSAK, sizeof(rSAK));
2691                                         cuid = bytes_to_num(rUIDBCC2, 4);
2692                                         cardSTATE = MFEMUL_WORK;
2693                                         LED_B_ON();
2694                                         if (MF_DBGLEVEL >= 4)   Dbprintf("--> WORK. anticol2 time: %d", GetTickCount() - selTimer);
2695                                         break;
2696                                 }
2697
2698                                 // i guess there is a command). go into the work state.
2699                                 if (len != 4) {
2700                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2701                                         break;
2702                                 }
2703                                 cardSTATE = MFEMUL_WORK;
2704                                 //goto lbWORK;
2705                                 //intentional fall-through to the next case-stmt
2706                         }
2707
2708                         case MFEMUL_WORK:{
2709                                 if (len == 0) {
2710                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2711                                         break;
2712                                 }
2713
2714                                 bool encrypted_data = (cardAUTHKEY != 0xFF) ;
2715
2716                                 if(encrypted_data) {
2717                                         // decrypt seqence
2718                                         mf_crypto1_decrypt(pcs, receivedCmd, len);
2719                                 }
2720
2721                                 if (len == 4 && (receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61)) {
2722                                         authTimer = GetTickCount();
2723                                         cardAUTHSC = receivedCmd[1] / 4;  // received block num
2724                                         cardAUTHKEY = receivedCmd[0] - 0x60;
2725                                         crypto1_destroy(pcs);//Added by martin
2726                                         crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
2727
2728                                         if (!encrypted_data) { // first authentication
2729                                                 if (MF_DBGLEVEL >= 4) Dbprintf("Reader authenticating for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY  );
2730
2731                                                 crypto1_word(pcs, cuid ^ nonce, 0);//Update crypto state
2732                                                 num_to_bytes(nonce, 4, rAUTH_AT); // Send nonce
2733                                         } else { // nested authentication
2734                                                 if (MF_DBGLEVEL >= 4) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %d",receivedCmd[1] ,receivedCmd[1],cardAUTHKEY );
2735                                                 ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0);
2736                                                 num_to_bytes(ans, 4, rAUTH_AT);
2737                                         }
2738
2739                                         EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2740                                         //Dbprintf("Sending rAUTH %02x%02x%02x%02x", rAUTH_AT[0],rAUTH_AT[1],rAUTH_AT[2],rAUTH_AT[3]);
2741                                         cardSTATE = MFEMUL_AUTH1;
2742                                         break;
2743                                 }
2744
2745                                 // rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued
2746                                 // BUT... ACK --> NACK
2747                                 if (len == 1 && receivedCmd[0] == CARD_ACK) {
2748                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2749                                         break;
2750                                 }
2751
2752                                 // rule 12 of 7.5.3. in ISO 14443-4. R(NAK) --> R(ACK)
2753                                 if (len == 1 && receivedCmd[0] == CARD_NACK_NA) {
2754                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2755                                         break;
2756                                 }
2757
2758                                 if(len != 4) {
2759                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2760                                         break;
2761                                 }
2762
2763                                 if(receivedCmd[0] == 0x30 // read block
2764                                                 || receivedCmd[0] == 0xA0 // write block
2765                                                 || receivedCmd[0] == 0xC0 // inc
2766                                                 || receivedCmd[0] == 0xC1 // dec
2767                                                 || receivedCmd[0] == 0xC2 // restore
2768                                                 || receivedCmd[0] == 0xB0) { // transfer
2769                                         if (receivedCmd[1] >= 16 * 4) {
2770                                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2771                                                 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]);
2772                                                 break;
2773                                         }
2774
2775                                         if (receivedCmd[1] / 4 != cardAUTHSC) {
2776                                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2777                                                 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);
2778                                                 break;
2779                                         }
2780                                 }
2781                                 // read block
2782                                 if (receivedCmd[0] == 0x30) {
2783                                         if (MF_DBGLEVEL >= 4) {
2784                                                 Dbprintf("Reader reading block %d (0x%02x)",receivedCmd[1],receivedCmd[1]);
2785                                         }
2786                                         emlGetMem(response, receivedCmd[1], 1);
2787                                         AppendCrc14443a(response, 16);
2788                                         mf_crypto1_encrypt(pcs, response, 18, response_par);
2789                                         EmSendCmdPar(response, 18, response_par);
2790                                         numReads++;
2791                                         if(exitAfterNReads > 0 && numReads >= exitAfterNReads) {
2792                                                 Dbprintf("%d reads done, exiting", numReads);
2793                                                 finished = true;
2794                                         }
2795                                         break;
2796                                 }
2797                                 // write block
2798                                 if (receivedCmd[0] == 0xA0) {
2799                                         if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0xA0 write block %d (%02x)",receivedCmd[1],receivedCmd[1]);
2800                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2801                                         cardSTATE = MFEMUL_WRITEBL2;
2802                                         cardWRBL = receivedCmd[1];
2803                                         break;
2804                                 }
2805                                 // increment, decrement, restore
2806                                 if (receivedCmd[0] == 0xC0 || receivedCmd[0] == 0xC1 || receivedCmd[0] == 0xC2) {
2807                                         if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2808                                         if (emlCheckValBl(receivedCmd[1])) {
2809                                                 if (MF_DBGLEVEL >= 4) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking");
2810                                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2811                                                 break;
2812                                         }
2813                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2814                                         if (receivedCmd[0] == 0xC1)
2815                                                 cardSTATE = MFEMUL_INTREG_INC;
2816                                         if (receivedCmd[0] == 0xC0)
2817                                                 cardSTATE = MFEMUL_INTREG_DEC;
2818                                         if (receivedCmd[0] == 0xC2)
2819                                                 cardSTATE = MFEMUL_INTREG_REST;
2820                                         cardWRBL = receivedCmd[1];
2821                                         break;
2822                                 }
2823                                 // transfer
2824                                 if (receivedCmd[0] == 0xB0) {
2825                                         if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x transfer block %d (%02x)",receivedCmd[0],receivedCmd[1],receivedCmd[1]);
2826                                         if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
2827                                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2828                                         else
2829                                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2830                                         break;
2831                                 }
2832                                 // halt
2833                                 if (receivedCmd[0] == 0x50 && receivedCmd[1] == 0x00) {
2834                                         LED_B_OFF();
2835                                         LED_C_OFF();
2836                                         cardSTATE = MFEMUL_HALTED;
2837                                         if (MF_DBGLEVEL >= 4)   Dbprintf("--> HALTED. Selected time: %d ms",  GetTickCount() - selTimer);
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                                 // RATS
2842                                 if (receivedCmd[0] == 0xe0) {//RATS
2843                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2844                                         break;
2845                                 }
2846                                 // command not allowed
2847                                 if (MF_DBGLEVEL >= 4)   Dbprintf("Received command not allowed, nacking");
2848                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2849                                 break;
2850                         }
2851                         case MFEMUL_WRITEBL2:{
2852                                 if (len == 18){
2853                                         mf_crypto1_decrypt(pcs, receivedCmd, len);
2854                                         emlSetMem(receivedCmd, cardWRBL, 1);
2855                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2856                                         cardSTATE = MFEMUL_WORK;
2857                                 } else {
2858                                         cardSTATE_TO_IDLE();
2859                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2860                                 }
2861                                 break;
2862                         }
2863
2864                         case MFEMUL_INTREG_INC:{
2865                                 mf_crypto1_decrypt(pcs, receivedCmd, len);
2866                                 memcpy(&ans, receivedCmd, 4);
2867                                 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2868                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2869                                         cardSTATE_TO_IDLE();
2870                                         break;
2871                                 }
2872                                 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2873                                 cardINTREG = cardINTREG + ans;
2874                                 cardSTATE = MFEMUL_WORK;
2875                                 break;
2876                         }
2877                         case MFEMUL_INTREG_DEC:{
2878                                 mf_crypto1_decrypt(pcs, receivedCmd, len);
2879                                 memcpy(&ans, receivedCmd, 4);
2880                                 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2881                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2882                                         cardSTATE_TO_IDLE();
2883                                         break;
2884                                 }
2885                                 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2886                                 cardINTREG = cardINTREG - ans;
2887                                 cardSTATE = MFEMUL_WORK;
2888                                 break;
2889                         }
2890                         case MFEMUL_INTREG_REST:{
2891                                 mf_crypto1_decrypt(pcs, receivedCmd, len);
2892                                 memcpy(&ans, receivedCmd, 4);
2893                                 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2894                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2895                                         cardSTATE_TO_IDLE();
2896                                         break;
2897                                 }
2898                                 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2899                                 cardSTATE = MFEMUL_WORK;
2900                                 break;
2901                         }
2902                 }
2903         }
2904
2905         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2906         LEDsoff();
2907
2908         if(flags & FLAG_INTERACTIVE)// Interactive mode flag, means we need to send ACK
2909         {
2910                 //May just aswell send the collected ar_nr in the response aswell
2911                 uint8_t len = ar_nr_collected*5*4;
2912                 cmd_send(CMD_ACK, CMD_SIMULATE_MIFARE_CARD, len, 0, &ar_nr_responses, len);
2913         }
2914
2915         if(flags & FLAG_NR_AR_ATTACK && MF_DBGLEVEL >= 1 )
2916         {
2917                 if(ar_nr_collected > 1 ) {
2918                         Dbprintf("Collected two pairs of AR/NR which can be used to extract keys from reader:");
2919                         Dbprintf("../tools/mfkey/mfkey32 %06x%08x %08x %08x %08x %08x %08x",
2920                                         ar_nr_responses[0], // UID1
2921                                         ar_nr_responses[1], // UID2
2922                                         ar_nr_responses[2], // NT
2923                                         ar_nr_responses[3], // AR1
2924                                         ar_nr_responses[4], // NR1
2925                                         ar_nr_responses[8], // AR2
2926                                         ar_nr_responses[9]  // NR2
2927                                         );
2928                         Dbprintf("../tools/mfkey/mfkey32v2 %06x%08x %08x %08x %08x %08x %08x %08x",
2929                                         ar_nr_responses[0], // UID1
2930                                         ar_nr_responses[1], // UID2
2931                                         ar_nr_responses[2], // NT1
2932                                         ar_nr_responses[3], // AR1
2933                                         ar_nr_responses[4], // NR1
2934                                         ar_nr_responses[7], // NT2
2935                                         ar_nr_responses[8], // AR2
2936                                         ar_nr_responses[9]  // NR2
2937                                         );
2938                 } else {
2939                         Dbprintf("Failed to obtain two AR/NR pairs!");
2940                         if(ar_nr_collected > 0 ) {
2941                                 Dbprintf("Only got these: UID=%07x%08x, nonce=%08x, AR1=%08x, NR1=%08x",
2942                                                 ar_nr_responses[0], // UID1
2943                                                 ar_nr_responses[1], // UID2
2944                                                 ar_nr_responses[2], // NT
2945                                                 ar_nr_responses[3], // AR1
2946                                                 ar_nr_responses[4]  // NR1
2947                                                 );
2948                         }
2949                 }
2950         }
2951         if (MF_DBGLEVEL >= 1)   Dbprintf("Emulator stopped. Tracing: %d  trace length: %d ", tracing, BigBuf_get_traceLen());
2952 }
2953
2954
2955 //-----------------------------------------------------------------------------
2956 // MIFARE sniffer.
2957 //
2958 //-----------------------------------------------------------------------------
2959 void RAMFUNC SniffMifare(uint8_t param) {
2960         // param:
2961         // bit 0 - trigger from first card answer
2962         // bit 1 - trigger from first reader 7-bit request
2963
2964         // C(red) A(yellow) B(green)
2965         LEDsoff();
2966         // init trace buffer
2967         clear_trace();
2968         set_tracing(TRUE);
2969
2970         // The command (reader -> tag) that we're receiving.
2971         // The length of a received command will in most cases be no more than 18 bytes.
2972         // So 32 should be enough!
2973         uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE];
2974         uint8_t receivedCmdPar[MAX_MIFARE_PARITY_SIZE];
2975         // The response (tag -> reader) that we're receiving.
2976         uint8_t receivedResponse[MAX_MIFARE_FRAME_SIZE];
2977         uint8_t receivedResponsePar[MAX_MIFARE_PARITY_SIZE];
2978
2979         iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
2980
2981         // free eventually allocated BigBuf memory
2982         BigBuf_free();
2983         // allocate the DMA buffer, used to stream samples from the FPGA
2984         uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
2985         uint8_t *data = dmaBuf;
2986         uint8_t previous_data = 0;
2987         int maxDataLen = 0;
2988         int dataLen = 0;
2989         bool ReaderIsActive = FALSE;
2990         bool TagIsActive = FALSE;
2991
2992         // Set up the demodulator for tag -> reader responses.
2993         DemodInit(receivedResponse, receivedResponsePar);
2994
2995         // Set up the demodulator for the reader -> tag commands
2996         UartInit(receivedCmd, receivedCmdPar);
2997
2998         // Setup for the DMA.
2999         FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
3000
3001         LED_D_OFF();
3002
3003         // init sniffer
3004         MfSniffInit();
3005
3006         // And now we loop, receiving samples.
3007         for(uint32_t sniffCounter = 0; TRUE; ) {
3008
3009                 if(BUTTON_PRESS()) {
3010                         DbpString("cancelled by button");
3011                         break;
3012                 }
3013
3014                 LED_A_ON();
3015                 WDT_HIT();
3016
3017                 if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time
3018                         // check if a transaction is completed (timeout after 2000ms).
3019                         // if yes, stop the DMA transfer and send what we have so far to the client
3020                         if (MfSniffSend(2000)) {
3021                                 // Reset everything - we missed some sniffed data anyway while the DMA was stopped
3022                                 sniffCounter = 0;
3023                                 data = dmaBuf;
3024                                 maxDataLen = 0;
3025                                 ReaderIsActive = FALSE;
3026                                 TagIsActive = FALSE;
3027                                 FpgaSetupSscDma((uint8_t *)dmaBuf, DMA_BUFFER_SIZE); // set transfer address and number of bytes. Start transfer.
3028                         }
3029                 }
3030
3031                 int register readBufDataP = data - dmaBuf;      // number of bytes we have processed so far
3032                 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred
3033                 if (readBufDataP <= dmaBufDataP){                       // we are processing the same block of data which is currently being transferred
3034                         dataLen = dmaBufDataP - readBufDataP;   // number of bytes still to be processed
3035                 } else {
3036                         dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed
3037                 }
3038                 // test for length of buffer
3039                 if(dataLen > maxDataLen) {                                      // we are more behind than ever...
3040                         maxDataLen = dataLen;
3041                         if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
3042                                 Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
3043                                 break;
3044                         }
3045                 }
3046                 if(dataLen < 1) continue;
3047
3048                 // primary buffer was stopped ( <-- we lost data!
3049                 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
3050                         AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
3051                         AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
3052                         Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
3053                 }
3054                 // secondary buffer sets as primary, secondary buffer was stopped
3055                 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
3056                         AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
3057                         AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
3058                 }
3059
3060                 LED_A_OFF();
3061
3062                 if (sniffCounter & 0x01) {
3063
3064                         if(!TagIsActive) {              // no need to try decoding tag data if the reader is sending
3065                                 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
3066                                 if(MillerDecoding(readerdata, (sniffCounter-1)*4)) {
3067                                         LED_C_INV();
3068                                         if (MfSniffLogic(receivedCmd, Uart.len, Uart.parity, Uart.bitCount, TRUE)) break;
3069
3070                                         /* And ready to receive another command. */
3071                                         UartReset();
3072
3073                                         /* And also reset the demod code */
3074                                         DemodReset();
3075                                 }
3076                                 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
3077                         }
3078
3079                         if(!ReaderIsActive) {           // no need to try decoding tag data if the reader is sending
3080                                 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
3081                                 if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) {
3082                                         LED_C_INV();
3083
3084                                         if (MfSniffLogic(receivedResponse, Demod.len, Demod.parity, Demod.bitCount, FALSE)) break;
3085
3086                                         // And ready to receive another response.
3087                                         DemodReset();
3088
3089                                         // And reset the Miller decoder including its (now outdated) input buffer
3090                                         UartInit(receivedCmd, receivedCmdPar);
3091                                         // why not UartReset?
3092                                 }
3093                                 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
3094                         }
3095                 }
3096
3097                 previous_data = *data;
3098                 sniffCounter++;
3099                 data++;
3100                 if(data == dmaBuf + DMA_BUFFER_SIZE) {
3101                         data = dmaBuf;
3102                 }
3103
3104         } // main cycle
3105
3106         FpgaDisableSscDma();
3107         MfSniffEnd();
3108         LEDsoff();
3109         Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len);
3110 }