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 #include "iso14443a.h"
  13
  14 static uint32_t iso14a_timeout;
  15 int rsamples = 0;
  16 uint8_t trigger = 0;
  17 // the block number for the ISO14443-4 PCB
  18 static uint8_t iso14_pcb_blocknum = 0;
  19
  20 static uint8_t* free_buffer_pointer;
  21
  22 //
  23 // ISO14443 timing:
  24 //
  25 // minimum time between the start bits of consecutive transfers from reader to tag: 7000 carrier (13.56Mhz) cycles
  26 #define REQUEST_GUARD_TIME (7000/16 + 1)
  27 // minimum time between last modulation of tag and next start bit from reader to tag: 1172 carrier cycles
  28 #define FRAME_DELAY_TIME_PICC_TO_PCD (1172/16 + 1)
  29 // bool LastCommandWasRequest = FALSE;
  30
  31 //
  32 // Total delays including SSC-Transfers between ARM and FPGA. These are in carrier clock cycles (1/13,56MHz)
  33 //
  34 // When the PM acts as reader and is receiving tag data, it takes
  35 // 3 ticks delay in the AD converter
  36 // 16 ticks until the modulation detector completes and sets curbit
  37 // 8 ticks until bit_to_arm is assigned from curbit
  38 // 8*16 ticks for the transfer from FPGA to ARM
  39 // 4*16 ticks until we measure the time
  40 // - 8*16 ticks because we measure the time of the previous transfer
  41 #define DELAY_AIR2ARM_AS_READER (3 + 16 + 8 + 8*16 + 4*16 - 8*16)
  42
  43 // When the PM acts as a reader and is sending, it takes
  44 // 4*16 ticks until we can write data to the sending hold register
  45 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
  46 // 8 ticks until the first transfer starts
  47 // 8 ticks later the FPGA samples the data
  48 // 1 tick to assign mod_sig_coil
  49 #define DELAY_ARM2AIR_AS_READER (4*16 + 8*16 + 8 + 8 + 1)
  50
  51 // When the PM acts as tag and is receiving it takes
  52 // 2 ticks delay in the RF part (for the first falling edge),
  53 // 3 ticks for the A/D conversion,
  54 // 8 ticks on average until the start of the SSC transfer,
  55 // 8 ticks until the SSC samples the first data
  56 // 7*16 ticks to complete the transfer from FPGA to ARM
  57 // 8 ticks until the next ssp_clk rising edge
  58 // 4*16 ticks until we measure the time
  59 // - 8*16 ticks because we measure the time of the previous transfer
  60 #define DELAY_AIR2ARM_AS_TAG (2 + 3 + 8 + 8 + 7*16 + 8 + 4*16 - 8*16)
  61
  62 // The FPGA will report its internal sending delay in
  63 uint16_t FpgaSendQueueDelay;
  64 // the 5 first bits are the number of bits buffered in mod_sig_buf
  65 // the last three bits are the remaining ticks/2 after the mod_sig_buf shift
  66 #define DELAY_FPGA_QUEUE (FpgaSendQueueDelay<<1)
  67
  68 // When the PM acts as tag and is sending, it takes
  69 // 4*16 ticks until we can write data to the sending hold register
  70 // 8*16 ticks until the SHR is transferred to the Sending Shift Register
  71 // 8 ticks until the first transfer starts
  72 // 8 ticks later the FPGA samples the data
  73 // + a varying number of ticks in the FPGA Delay Queue (mod_sig_buf)
  74 // + 1 tick to assign mod_sig_coil
  75 #define DELAY_ARM2AIR_AS_TAG (4*16 + 8*16 + 8 + 8 + DELAY_FPGA_QUEUE + 1)
  76
  77 // When the PM acts as sniffer and is receiving tag data, it takes
  78 // 3 ticks A/D conversion
  79 // 14 ticks to complete the modulation detection
  80 // 8 ticks (on average) until the result is stored in to_arm
  81 // + the delays in transferring data - which is the same for
  82 // sniffing reader and tag data and therefore not relevant
  83 #define DELAY_TAG_AIR2ARM_AS_SNIFFER (3 + 14 + 8)
  84
  85 // When the PM acts as sniffer and is receiving reader data, it takes
  86 // 2 ticks delay in analogue RF receiver (for the falling edge of the
  87 // start bit, which marks the start of the communication)
  88 // 3 ticks A/D conversion
  89 // 8 ticks on average until the data is stored in to_arm.
  90 // + the delays in transferring data - which is the same for
  91 // sniffing reader and tag data and therefore not relevant
  92 #define DELAY_READER_AIR2ARM_AS_SNIFFER (2 + 3 + 8)
  93
  94 //variables used for timing purposes:
  95 //these are in ssp_clk cycles:
  96 static uint32_t NextTransferTime;
  97 static uint32_t LastTimeProxToAirStart;
  98 static uint32_t LastProxToAirDuration;
  99
 100 // CARD TO READER - manchester
 101 // Sequence D: 11110000 modulation with subcarrier during first half
 102 // Sequence E: 00001111 modulation with subcarrier during second half
 103 // Sequence F: 00000000 no modulation with subcarrier
 104 // READER TO CARD - miller
 105 // Sequence X: 00001100 drop after half a period
 106 // Sequence Y: 00000000 no drop
 107 // Sequence Z: 11000000 drop at start
 108 #define SEC_D 0xf0
 109 #define SEC_E 0x0f
 110 #define SEC_F 0x00
 111 #define SEC_X 0x0c
 112 #define SEC_Y 0x00
 113 #define SEC_Z 0xc0
 114
 115 void iso14a_set_trigger(bool enable) {
 116         trigger = enable;
 117 }
 118
 119 void iso14a_set_timeout(uint32_t timeout) {
 120         iso14a_timeout = timeout;
 121         if(MF_DBGLEVEL >= 3) Dbprintf("ISO14443A Timeout set to %ld (%dms)", iso14a_timeout, iso14a_timeout / 106);
 122 }
 123
 124 void iso14a_set_ATS_timeout(uint8_t *ats) {
 125         uint8_t tb1;
 126         uint8_t fwi;
 127         uint32_t fwt;
 128
 129         if (ats[0] > 1) {                                                       // there is a format byte T0
 130                 if ((ats[1] & 0x20) == 0x20) {                  // there is an interface byte TB(1)
 131
 132                         if ((ats[1] & 0x10) == 0x10)            // there is an interface byte TA(1) preceding TB(1)
 133                                 tb1 = ats[3];
 134                         else
 135                                 tb1 = ats[2];
 136
 137                         fwi = (tb1 & 0xf0) >> 4;                        // frame waiting indicator (FWI)
 138                         fwt = 256 * 16 * (1 << fwi);            // frame waiting time (FWT) in 1/fc
 139                         //fwt = 4096 * (1 << fwi);
 140
 141                         iso14a_set_timeout(fwt/(8*16));
 142                         //iso14a_set_timeout(fwt/128);
 143                 }
 144         }
 145 }
 146
 147 //-----------------------------------------------------------------------------
 148 // Generate the parity value for a byte sequence
 149 //
 150 //-----------------------------------------------------------------------------
 151 void GetParity(const uint8_t *pbtCmd, uint16_t iLen, uint8_t *par) {
 152         uint16_t paritybit_cnt = 0;
 153         uint16_t paritybyte_cnt = 0;
 154         uint8_t parityBits = 0;
 155
 156         for (uint16_t i = 0; i < iLen; i++) {
 157                 // Generate the parity bits
 158                 parityBits |= ((oddparity8(pbtCmd[i])) << (7-paritybit_cnt));
 159                 if (paritybit_cnt == 7) {
 160                         par[paritybyte_cnt] = parityBits;       // save 8 Bits parity
 161                         parityBits = 0;                                         // and advance to next Parity Byte
 162                         paritybyte_cnt++;
 163                         paritybit_cnt = 0;
 164                 } else {
 165                         paritybit_cnt++;
 166                 }
 167         }
 168
 169         // save remaining parity bits
 170         par[paritybyte_cnt] = parityBits;
 171 }
 172
 173 void AppendCrc14443a(uint8_t* data, int len) {
 174         ComputeCrc14443(CRC_14443_A,data,len,data+len,data+len+1);
 175 }
 176
 177 //=============================================================================
 178 // ISO 14443 Type A - Miller decoder
 179 //=============================================================================
 180 // Basics:
 181 // This decoder is used when the PM3 acts as a tag.
 182 // The reader will generate "pauses" by temporarily switching of the field.
 183 // At the PM3 antenna we will therefore measure a modulated antenna voltage.
 184 // The FPGA does a comparison with a threshold and would deliver e.g.:
 185 // ........  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  .......
 186 // The Miller decoder needs to identify the following sequences:
 187 // 2 (or 3) ticks pause followed by 6 (or 5) ticks unmodulated:         pause at beginning - Sequence Z ("start of communication" or a "0")
 188 // 8 ticks without a modulation:                                                                        no pause - Sequence Y (a "0" or "end of communication" or "no information")
 189 // 4 ticks unmodulated followed by 2 (or 3) ticks pause:                        pause in second half - Sequence X (a "1")
 190 // Note 1: the bitstream may start at any time. We therefore need to sync.
 191 // Note 2: the interpretation of Sequence Y and Z depends on the preceding sequence.
 192 //-----------------------------------------------------------------------------
 193 static tUart Uart;
 194
 195 // Lookup-Table to decide if 4 raw bits are a modulation.
 196 // We accept the following:
 197 // 0001  -   a 3 tick wide pause
 198 // 0011  -   a 2 tick wide pause, or a three tick wide pause shifted left
 199 // 0111  -   a 2 tick wide pause shifted left
 200 // 1001  -   a 2 tick wide pause shifted right
 201 const bool Mod_Miller_LUT[] = {
 202         FALSE,  TRUE, FALSE, TRUE,  FALSE, FALSE, FALSE, TRUE,
 203         FALSE,  TRUE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE
 204 };
 205 #define IsMillerModulationNibble1(b) (Mod_Miller_LUT[(b & 0x000000F0) >> 4])
 206 #define IsMillerModulationNibble2(b) (Mod_Miller_LUT[(b & 0x0000000F)])
 207
 208 void UartReset() {
 209         Uart.state = STATE_UNSYNCD;
 210         Uart.bitCount = 0;
 211         Uart.len = 0;                                           // number of decoded data bytes
 212         Uart.parityLen = 0;                                     // number of decoded parity bytes
 213         Uart.shiftReg = 0;                                      // shiftreg to hold decoded data bits
 214         Uart.parityBits = 0;                            // holds 8 parity bits
 215         Uart.startTime = 0;
 216         Uart.endTime = 0;
 217
 218         Uart.byteCntMax = 0;
 219         Uart.posCnt = 0;
 220         Uart.syncBit = 9999;
 221 }
 222
 223 void UartInit(uint8_t *data, uint8_t *parity) {
 224         Uart.output = data;
 225         Uart.parity = parity;
 226         Uart.fourBits = 0x00000000;                     // clear the buffer for 4 Bits
 227         UartReset();
 228 }
 229
 230 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
 231 static RAMFUNC bool MillerDecoding(uint8_t bit, uint32_t non_real_time) {
 232         Uart.fourBits = (Uart.fourBits << 8) | bit;
 233
 234         if (Uart.state == STATE_UNSYNCD) {                                                                                      // not yet synced
 235                         Uart.syncBit = 9999;                                                                                            // not set
 236
 237                 // 00x11111 2|3 ticks pause followed by 6|5 ticks unmodulated           Sequence Z (a "0" or "start of communication")
 238                 // 11111111 8 ticks unmodulation                                                                        Sequence Y (a "0" or "end of communication" or "no information")
 239                 // 111100x1 4 ticks unmodulated followed by 2|3 ticks pause                     Sequence X (a "1")
 240
 241                 // The start bit is one ore more Sequence Y followed by a Sequence Z (... 11111111 00x11111). We need to distinguish from
 242                 // Sequence X followed by Sequence Y followed by Sequence Z     (111100x1 11111111 00x11111)
 243                 // we therefore look for a ...xx1111 11111111 00x11111xxxxxx... pattern
 244                 // (12 '1's followed by 2 '0's, eventually followed by another '0', followed by 5 '1's)
 245                 //
 246 #define ISO14443A_STARTBIT_MASK         0x07FFEF80              // mask is    00001111 11111111 1110 1111 10000000
 247 #define ISO14443A_STARTBIT_PATTERN      0x07FF8F80              // pattern is 00001111 11111111 1000 1111 10000000
 248
 249                 if              ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 0)) == ISO14443A_STARTBIT_PATTERN >> 0) Uart.syncBit = 7;
 250                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 1)) == ISO14443A_STARTBIT_PATTERN >> 1) Uart.syncBit = 6;
 251                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 2)) == ISO14443A_STARTBIT_PATTERN >> 2) Uart.syncBit = 5;
 252                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 3)) == ISO14443A_STARTBIT_PATTERN >> 3) Uart.syncBit = 4;
 253                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 4)) == ISO14443A_STARTBIT_PATTERN >> 4) Uart.syncBit = 3;
 254                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 5)) == ISO14443A_STARTBIT_PATTERN >> 5) Uart.syncBit = 2;
 255                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 6)) == ISO14443A_STARTBIT_PATTERN >> 6) Uart.syncBit = 1;
 256                 else if ((Uart.fourBits & (ISO14443A_STARTBIT_MASK >> 7)) == ISO14443A_STARTBIT_PATTERN >> 7) Uart.syncBit = 0;
 257
 258                 if (Uart.syncBit != 9999) {                                                                                             // found a sync bit
 259                         Uart.startTime = non_real_time ? non_real_time : (GetCountSspClk() & 0xfffffff8);
 260                         Uart.startTime -= Uart.syncBit;
 261                         Uart.endTime = Uart.startTime;
 262                         Uart.state = STATE_START_OF_COMMUNICATION;
 263                 }
 264         } else {
 265
 266                 if (IsMillerModulationNibble1(Uart.fourBits >> Uart.syncBit)) {
 267                         if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) {         // Modulation in both halves - error
 268                                 UartReset();
 269                         } else {                                                                                                                        // Modulation in first half = Sequence Z = logic "0"
 270                                 if (Uart.state == STATE_MILLER_X) {                                                             // error - must not follow after X
 271                                         UartReset();
 272                                 } else {
 273                                         Uart.bitCount++;
 274                                         Uart.shiftReg = (Uart.shiftReg >> 1);                                           // add a 0 to the shiftreg
 275                                         Uart.state = STATE_MILLER_Z;
 276                                         Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 6;
 277                                         if(Uart.bitCount >= 9) {                                                                        // if we decoded a full byte (including parity)
 278                                                 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
 279                                                 Uart.parityBits <<= 1;                                                                  // make room for the parity bit
 280                                                 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01);               // store parity bit
 281                                                 Uart.bitCount = 0;
 282                                                 Uart.shiftReg = 0;
 283                                                 if((Uart.len&0x0007) == 0) {                                                    // every 8 data bytes
 284                                                         Uart.parity[Uart.parityLen++] = Uart.parityBits;        // store 8 parity bits
 285                                                         Uart.parityBits = 0;
 286                                                 }
 287                                         }
 288                                 }
 289                         }
 290                 } else {
 291                         if (IsMillerModulationNibble2(Uart.fourBits >> Uart.syncBit)) {         // Modulation second half = Sequence X = logic "1"
 292                                 Uart.bitCount++;
 293                                 Uart.shiftReg = (Uart.shiftReg >> 1) | 0x100;                                   // add a 1 to the shiftreg
 294                                 Uart.state = STATE_MILLER_X;
 295                                 Uart.endTime = Uart.startTime + 8*(9*Uart.len + Uart.bitCount + 1) - 2;
 296                                 if(Uart.bitCount >= 9) {                                                                                // if we decoded a full byte (including parity)
 297                                         Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
 298                                         Uart.parityBits <<= 1;                                                                          // make room for the new parity bit
 299                                         Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01);                       // store parity bit
 300                                         Uart.bitCount = 0;
 301                                         Uart.shiftReg = 0;
 302                                         if ((Uart.len&0x0007) == 0) {                                                           // every 8 data bytes
 303                                                 Uart.parity[Uart.parityLen++] = Uart.parityBits;                // store 8 parity bits
 304                                                 Uart.parityBits = 0;
 305                                         }
 306                                 }
 307                         } else {                                                                                                                        // no modulation in both halves - Sequence Y
 308                                 if (Uart.state == STATE_MILLER_Z || Uart.state == STATE_MILLER_Y) {     // Y after logic "0" - End of Communication
 309                                         Uart.state = STATE_UNSYNCD;
 310                                         Uart.bitCount--;                                                                                        // last "0" was part of EOC sequence
 311                                         Uart.shiftReg <<= 1;                                                                            // drop it
 312                                         if(Uart.bitCount > 0) {                                                                         // if we decoded some bits
 313                                                 Uart.shiftReg >>= (9 - Uart.bitCount);                                  // right align them
 314                                                 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);               // add last byte to the output
 315                                                 Uart.parityBits <<= 1;                                                                  // add a (void) parity bit
 316                                                 Uart.parityBits <<= (8 - (Uart.len&0x0007));                    // left align parity bits
 317                                                 Uart.parity[Uart.parityLen++] = Uart.parityBits;                // and store it
 318                                                 return TRUE;
 319                                         } else if (Uart.len & 0x0007) {                                                         // there are some parity bits to store
 320                                                 Uart.parityBits <<= (8 - (Uart.len&0x0007));                    // left align remaining parity bits
 321                                                 Uart.parity[Uart.parityLen++] = Uart.parityBits;                // and store them
 322                                         }
 323                                         if (Uart.len) {
 324                                                 return TRUE;                                                                                    // we are finished with decoding the raw data sequence
 325                                         } else {
 326                                                 UartReset();                                                                                    // Nothing received - start over
 327                                         }
 328                                 }
 329                                 if (Uart.state == STATE_START_OF_COMMUNICATION) {                               // error - must not follow directly after SOC
 330                                         UartReset();
 331                                 } else {                                                                                                                // a logic "0"
 332                                         Uart.bitCount++;
 333                                         Uart.shiftReg = (Uart.shiftReg >> 1);                                           // add a 0 to the shiftreg
 334                                         Uart.state = STATE_MILLER_Y;
 335                                         if(Uart.bitCount >= 9) {                                                                        // if we decoded a full byte (including parity)
 336                                                 Uart.output[Uart.len++] = (Uart.shiftReg & 0xff);
 337                                                 Uart.parityBits <<= 1;                                                                  // make room for the parity bit
 338                                                 Uart.parityBits |= ((Uart.shiftReg >> 8) & 0x01);               // store parity bit
 339                                                 Uart.bitCount = 0;
 340                                                 Uart.shiftReg = 0;
 341                                                 if ((Uart.len&0x0007) == 0) {                                                   // every 8 data bytes
 342                                                         Uart.parity[Uart.parityLen++] = Uart.parityBits;        // store 8 parity bits
 343                                                         Uart.parityBits = 0;
 344                                                 }
 345                                         }
 346                                 }
 347                         }
 348                 }
 349         }
 350     return FALSE;       // not finished yet, need more data
 351 }
 352
 353 //=============================================================================
 354 // ISO 14443 Type A - Manchester decoder
 355 //=============================================================================
 356 // Basics:
 357 // This decoder is used when the PM3 acts as a reader.
 358 // The tag will modulate the reader field by asserting different loads to it. As a consequence, the voltage
 359 // at the reader antenna will be modulated as well. The FPGA detects the modulation for us and would deliver e.g. the following:
 360 // ........ 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 .......
 361 // The Manchester decoder needs to identify the following sequences:
 362 // 4 ticks modulated followed by 4 ticks unmodulated:   Sequence D = 1 (also used as "start of communication")
 363 // 4 ticks unmodulated followed by 4 ticks modulated:   Sequence E = 0
 364 // 8 ticks unmodulated:                                                                 Sequence F = end of communication
 365 // 8 ticks modulated:                                                                   A collision. Save the collision position and treat as Sequence D
 366 // Note 1: the bitstream may start at any time. We therefore need to sync.
 367 // Note 2: parameter offset is used to determine the position of the parity bits (required for the anticollision command only)
 368 static tDemod Demod;
 369
 370 // Lookup-Table to decide if 4 raw bits are a modulation.
 371 // We accept three or four "1" in any position
 372 const bool Mod_Manchester_LUT[] = {
 373         FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, FALSE, TRUE,
 374         FALSE, FALSE, FALSE, TRUE,  FALSE, TRUE,  TRUE,  TRUE
 375 };
 376
 377 #define IsManchesterModulationNibble1(b) (Mod_Manchester_LUT[(b & 0x00F0) >> 4])
 378 #define IsManchesterModulationNibble2(b) (Mod_Manchester_LUT[(b & 0x000F)])
 379
 380 void DemodReset() {
 381         Demod.state = DEMOD_UNSYNCD;
 382         Demod.len = 0;                                          // number of decoded data bytes
 383         Demod.parityLen = 0;
 384         Demod.shiftReg = 0;                                     // shiftreg to hold decoded data bits
 385         Demod.parityBits = 0;                           //
 386         Demod.collisionPos = 0;                         // Position of collision bit
 387         Demod.twoBits = 0xffff;                         // buffer for 2 Bits
 388         Demod.highCnt = 0;
 389         Demod.startTime = 0;
 390         Demod.endTime = 0;
 391         Demod.bitCount = 0;
 392         Demod.syncBit = 0xFFFF;
 393         Demod.samples = 0;
 394 }
 395
 396 void DemodInit(uint8_t *data, uint8_t *parity) {
 397         Demod.output = data;
 398         Demod.parity = parity;
 399         DemodReset();
 400 }
 401
 402 // use parameter non_real_time to provide a timestamp. Set to 0 if the decoder should measure real time
 403 static RAMFUNC int ManchesterDecoding(uint8_t bit, uint16_t offset, uint32_t non_real_time) {
 404         Demod.twoBits = (Demod.twoBits << 8) | bit;
 405
 406         if (Demod.state == DEMOD_UNSYNCD) {
 407
 408                 if (Demod.highCnt < 2) {                                                                                        // wait for a stable unmodulated signal
 409                         if (Demod.twoBits == 0x0000) {
 410                                 Demod.highCnt++;
 411                         } else {
 412                                 Demod.highCnt = 0;
 413                         }
 414                 } else {
 415                         Demod.syncBit = 0xFFFF;                 // not set
 416                         if              ((Demod.twoBits & 0x7700) == 0x7000) Demod.syncBit = 7;
 417                         else if ((Demod.twoBits & 0x3B80) == 0x3800) Demod.syncBit = 6;
 418                         else if ((Demod.twoBits & 0x1DC0) == 0x1C00) Demod.syncBit = 5;
 419                         else if ((Demod.twoBits & 0x0EE0) == 0x0E00) Demod.syncBit = 4;
 420                         else if ((Demod.twoBits & 0x0770) == 0x0700) Demod.syncBit = 3;
 421                         else if ((Demod.twoBits & 0x03B8) == 0x0380) Demod.syncBit = 2;
 422                         else if ((Demod.twoBits & 0x01DC) == 0x01C0) Demod.syncBit = 1;
 423                         else if ((Demod.twoBits & 0x00EE) == 0x00E0) Demod.syncBit = 0;
 424                         if (Demod.syncBit != 0xFFFF) {
 425                                 Demod.startTime = non_real_time?non_real_time:(GetCountSspClk() & 0xfffffff8);
 426                                 Demod.startTime -= Demod.syncBit;
 427                                 Demod.bitCount = offset;                        // number of decoded data bits
 428                                 Demod.state = DEMOD_MANCHESTER_DATA;
 429                         }
 430                 }
 431         } else {
 432
 433                 if (IsManchesterModulationNibble1(Demod.twoBits >> Demod.syncBit)) {            // modulation in first half
 434                         if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) {    // ... and in second half = collision
 435                                 if (!Demod.collisionPos) {
 436                                         Demod.collisionPos = (Demod.len << 3) + Demod.bitCount;
 437                                 }
 438                         }                                                                                                                       // modulation in first half only - Sequence D = 1
 439                         Demod.bitCount++;
 440                         Demod.shiftReg = (Demod.shiftReg >> 1) | 0x100;                         // in both cases, add a 1 to the shiftreg
 441                         if(Demod.bitCount == 9) {                                                                       // if we decoded a full byte (including parity)
 442                                 Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
 443                                 Demod.parityBits <<= 1;                                                                 // make room for the parity bit
 444                                 Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01);     // store parity bit
 445                                 Demod.bitCount = 0;
 446                                 Demod.shiftReg = 0;
 447                                 if((Demod.len&0x0007) == 0) {                                                   // every 8 data bytes
 448                                         Demod.parity[Demod.parityLen++] = Demod.parityBits;     // store 8 parity bits
 449                                         Demod.parityBits = 0;
 450                                 }
 451                         }
 452                         Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1) - 4;
 453                 } else {                                                                                                                // no modulation in first half
 454                         if (IsManchesterModulationNibble2(Demod.twoBits >> Demod.syncBit)) {    // and modulation in second half = Sequence E = 0
 455                                 Demod.bitCount++;
 456                                 Demod.shiftReg = (Demod.shiftReg >> 1);                                 // add a 0 to the shiftreg
 457                                 if(Demod.bitCount >= 9) {                                                               // if we decoded a full byte (including parity)
 458                                         Demod.output[Demod.len++] = (Demod.shiftReg & 0xff);
 459                                         Demod.parityBits <<= 1;                                                         // make room for the new parity bit
 460                                         Demod.parityBits |= ((Demod.shiftReg >> 8) & 0x01); // store parity bit
 461                                         Demod.bitCount = 0;
 462                                         Demod.shiftReg = 0;
 463                                         if ((Demod.len&0x0007) == 0) {                                          // every 8 data bytes
 464                                                 Demod.parity[Demod.parityLen++] = Demod.parityBits;     // store 8 parity bits1
 465                                                 Demod.parityBits = 0;
 466                                         }
 467                                 }
 468                                 Demod.endTime = Demod.startTime + 8*(9*Demod.len + Demod.bitCount + 1);
 469                         } else {                                                                                                        // no modulation in both halves - End of communication
 470                                 if(Demod.bitCount > 0) {                                                                // there are some remaining data bits
 471                                         Demod.shiftReg >>= (9 - Demod.bitCount);                        // right align the decoded bits
 472                                         Demod.output[Demod.len++] = Demod.shiftReg & 0xff;      // and add them to the output
 473                                         Demod.parityBits <<= 1;                                                         // add a (void) parity bit
 474                                         Demod.parityBits <<= (8 - (Demod.len&0x0007));          // left align remaining parity bits
 475                                         Demod.parity[Demod.parityLen++] = Demod.parityBits;     // and store them
 476                                         return TRUE;
 477                                 } else if (Demod.len & 0x0007) {                                                // there are some parity bits to store
 478                                         Demod.parityBits <<= (8 - (Demod.len&0x0007));          // left align remaining parity bits
 479                                         Demod.parity[Demod.parityLen++] = Demod.parityBits;     // and store them
 480                                 }
 481                                 if (Demod.len) {
 482                                         return TRUE;                                                                            // we are finished with decoding the raw data sequence
 483                                 } else {                                                                                                // nothing received. Start over
 484                                         DemodReset();
 485                                 }
 486                         }
 487                 }
 488         }
 489     return FALSE;       // not finished yet, need more data
 490 }
 491
 492 //=============================================================================
 493 // Finally, a `sniffer' for ISO 14443 Type A
 494 // Both sides of communication!
 495 //=============================================================================
 496
 497 //-----------------------------------------------------------------------------
 498 // Record the sequence of commands sent by the reader to the tag, with
 499 // triggering so that we start recording at the point that the tag is moved
 500 // near the reader.
 501 // "hf 14a sniff"
 502 //-----------------------------------------------------------------------------
 503 void RAMFUNC SniffIso14443a(uint8_t param) {
 504         // param:
 505         // bit 0 - trigger from first card answer
 506         // bit 1 - trigger from first reader 7-bit request
 507         LEDsoff();
 508
 509         iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
 510
 511         // Allocate memory from BigBuf for some buffers
 512         // free all previous allocations first
 513         BigBuf_free(); BigBuf_Clear_ext(false);
 514         clear_trace();
 515         set_tracing(TRUE);
 516
 517         // The command (reader -> tag) that we're receiving.
 518         uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
 519         uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
 520
 521         // The response (tag -> reader) that we're receiving.
 522         uint8_t *receivedResponse = BigBuf_malloc(MAX_FRAME_SIZE);
 523         uint8_t *receivedResponsePar = BigBuf_malloc(MAX_PARITY_SIZE);
 524
 525         // The DMA buffer, used to stream samples from the FPGA
 526         uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
 527
 528         uint8_t *data = dmaBuf;
 529         uint8_t previous_data = 0;
 530         int maxDataLen = 0;
 531         int dataLen = 0;
 532         bool TagIsActive = FALSE;
 533         bool ReaderIsActive = FALSE;
 534
 535         // Set up the demodulator for tag -> reader responses.
 536         DemodInit(receivedResponse, receivedResponsePar);
 537
 538         // Set up the demodulator for the reader -> tag commands
 539         UartInit(receivedCmd, receivedCmdPar);
 540
 541         // Setup and start DMA.
 542         if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, DMA_BUFFER_SIZE) ){
 543                 if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting");
 544                 return;
 545         }
 546
 547         // We won't start recording the frames that we acquire until we trigger;
 548         // a good trigger condition to get started is probably when we see a
 549         // response from the tag.
 550         // triggered == FALSE -- to wait first for card
 551         bool triggered = !(param & 0x03);
 552
 553         // And now we loop, receiving samples.
 554         for(uint32_t rsamples = 0; TRUE; ) {
 555
 556                 if(BUTTON_PRESS()) {
 557                         DbpString("cancelled by button");
 558                         break;
 559                 }
 560
 561                 LED_A_ON();
 562                 WDT_HIT();
 563
 564                 int register readBufDataP = data - dmaBuf;
 565                 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR;
 566                 if (readBufDataP <= dmaBufDataP){
 567                         dataLen = dmaBufDataP - readBufDataP;
 568                 } else {
 569                         dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP;
 570                 }
 571                 // test for length of buffer
 572                 if(dataLen > maxDataLen) {
 573                         maxDataLen = dataLen;
 574                         if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
 575                                 Dbprintf("blew circular buffer! dataLen=%d", dataLen);
 576                                 break;
 577                         }
 578                 }
 579                 if(dataLen < 1) continue;
 580
 581                 // primary buffer was stopped( <-- we lost data!
 582                 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
 583                         AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
 584                         AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
 585                         Dbprintf("RxEmpty ERROR!!! data length:%d", dataLen); // temporary
 586                 }
 587                 // secondary buffer sets as primary, secondary buffer was stopped
 588                 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
 589                         AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
 590                         AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
 591                 }
 592
 593                 LED_A_OFF();
 594
 595                 if (rsamples & 0x01) {                          // Need two samples to feed Miller and Manchester-Decoder
 596
 597                         if(!TagIsActive) {              // no need to try decoding reader data if the tag is sending
 598                                 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
 599                                 if (MillerDecoding(readerdata, (rsamples-1)*4)) {
 600                                         LED_C_ON();
 601
 602                                         // check - if there is a short 7bit request from reader
 603                                         if ((!triggered) && (param & 0x02) && (Uart.len == 1) && (Uart.bitCount == 7)) triggered = TRUE;
 604
 605                                         if(triggered) {
 606                                                 if (!LogTrace(receivedCmd,
 607                                                                                 Uart.len,
 608                                                                                 Uart.startTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
 609                                                                                 Uart.endTime*16 - DELAY_READER_AIR2ARM_AS_SNIFFER,
 610                                                                                 Uart.parity,
 611                                                                                 TRUE)) break;
 612                                         }
 613                                         /* And ready to receive another command. */
 614                                         UartReset();
 615                                         /* And also reset the demod code, which might have been */
 616                                         /* false-triggered by the commands from the reader. */
 617                                         DemodReset();
 618                                         LED_B_OFF();
 619                                 }
 620                                 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
 621                         }
 622
 623                         if(!ReaderIsActive) {           // no need to try decoding tag data if the reader is sending - and we cannot afford the time
 624                                 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
 625                                 if(ManchesterDecoding(tagdata, 0, (rsamples-1)*4)) {
 626                                         LED_B_ON();
 627
 628                                         if (!LogTrace(receivedResponse,
 629                                                                         Demod.len,
 630                                                                         Demod.startTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
 631                                                                         Demod.endTime*16 - DELAY_TAG_AIR2ARM_AS_SNIFFER,
 632                                                                         Demod.parity,
 633                                                                         FALSE)) break;
 634
 635                                         if ((!triggered) && (param & 0x01)) triggered = TRUE;
 636
 637                                         // And ready to receive another response.
 638                                         DemodReset();
 639                                         // And reset the Miller decoder including itS (now outdated) input buffer
 640                                         UartInit(receivedCmd, receivedCmdPar);
 641                                         LED_C_OFF();
 642                                 }
 643                                 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
 644                         }
 645                 }
 646
 647                 previous_data = *data;
 648                 rsamples++;
 649                 data++;
 650                 if(data == dmaBuf + DMA_BUFFER_SIZE) {
 651                         data = dmaBuf;
 652                 }
 653         } // main cycle
 654
 655         if (MF_DBGLEVEL >= 1) {
 656                 Dbprintf("maxDataLen=%d, Uart.state=%x, Uart.len=%d", maxDataLen, Uart.state, Uart.len);
 657                 Dbprintf("traceLen=%d, Uart.output[0]=%08x", BigBuf_get_traceLen(), (uint32_t)Uart.output[0]);
 658         }
 659         FpgaDisableSscDma();
 660         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
 661         LEDsoff();
 662         set_tracing(FALSE);
 663 }
 664
 665 //-----------------------------------------------------------------------------
 666 // Prepare tag messages
 667 //-----------------------------------------------------------------------------
 668 static void CodeIso14443aAsTagPar(const uint8_t *cmd, uint16_t len, uint8_t *parity) {
 669         ToSendReset();
 670
 671         // Correction bit, might be removed when not needed
 672         ToSendStuffBit(0);
 673         ToSendStuffBit(0);
 674         ToSendStuffBit(0);
 675         ToSendStuffBit(0);
 676         ToSendStuffBit(1);  // 1
 677         ToSendStuffBit(0);
 678         ToSendStuffBit(0);
 679         ToSendStuffBit(0);
 680
 681         // Send startbit
 682         ToSend[++ToSendMax] = SEC_D;
 683         LastProxToAirDuration = 8 * ToSendMax - 4;
 684
 685         for(uint16_t i = 0; i < len; i++) {
 686                 uint8_t b = cmd[i];
 687
 688                 // Data bits
 689                 for(uint16_t j = 0; j < 8; j++) {
 690                         if(b & 1) {
 691                                 ToSend[++ToSendMax] = SEC_D;
 692                         } else {
 693                                 ToSend[++ToSendMax] = SEC_E;
 694                         }
 695                         b >>= 1;
 696                 }
 697
 698                 // Get the parity bit
 699                 if (parity[i>>3] & (0x80>>(i&0x0007))) {
 700                         ToSend[++ToSendMax] = SEC_D;
 701                         LastProxToAirDuration = 8 * ToSendMax - 4;
 702                 } else {
 703                         ToSend[++ToSendMax] = SEC_E;
 704                         LastProxToAirDuration = 8 * ToSendMax;
 705                 }
 706         }
 707
 708         // Send stopbit
 709         ToSend[++ToSendMax] = SEC_F;
 710
 711         // Convert from last byte pos to length
 712         ++ToSendMax;
 713 }
 714
 715 static void CodeIso14443aAsTag(const uint8_t *cmd, uint16_t len) {
 716         uint8_t par[MAX_PARITY_SIZE] = {0};
 717         GetParity(cmd, len, par);
 718         CodeIso14443aAsTagPar(cmd, len, par);
 719 }
 720
 721 static void Code4bitAnswerAsTag(uint8_t cmd) {
 722         uint8_t b = cmd;
 723
 724         ToSendReset();
 725
 726         // Correction bit, might be removed when not needed
 727         ToSendStuffBit(0);
 728         ToSendStuffBit(0);
 729         ToSendStuffBit(0);
 730         ToSendStuffBit(0);
 731         ToSendStuffBit(1);  // 1
 732         ToSendStuffBit(0);
 733         ToSendStuffBit(0);
 734         ToSendStuffBit(0);
 735
 736         // Send startbit
 737         ToSend[++ToSendMax] = SEC_D;
 738
 739         for(uint8_t i = 0; i < 4; i++) {
 740                 if(b & 1) {
 741                         ToSend[++ToSendMax] = SEC_D;
 742                         LastProxToAirDuration = 8 * ToSendMax - 4;
 743                 } else {
 744                         ToSend[++ToSendMax] = SEC_E;
 745                         LastProxToAirDuration = 8 * ToSendMax;
 746                 }
 747                 b >>= 1;
 748         }
 749
 750         // Send stopbit
 751         ToSend[++ToSendMax] = SEC_F;
 752
 753         // Convert from last byte pos to length
 754         ToSendMax++;
 755 }
 756
 757 //-----------------------------------------------------------------------------
 758 // Wait for commands from reader
 759 // Stop when button is pressed
 760 // Or return TRUE when command is captured
 761 //-----------------------------------------------------------------------------
 762 int GetIso14443aCommandFromReader(uint8_t *received, uint8_t *parity, int *len) {
 763     // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
 764     // only, since we are receiving, not transmitting).
 765     // Signal field is off with the appropriate LED
 766     LED_D_OFF();
 767     FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
 768
 769     // Now run a `software UART` on the stream of incoming samples.
 770         UartInit(received, parity);
 771
 772         // clear RXRDY:
 773     uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
 774
 775     for(;;) {
 776         WDT_HIT();
 777
 778         if(BUTTON_PRESS()) return FALSE;
 779
 780         if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
 781             b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
 782                         if(MillerDecoding(b, 0)) {
 783                                 *len = Uart.len;
 784                                 return TRUE;
 785                         }
 786                 }
 787     }
 788 }
 789
 790 bool prepare_tag_modulation(tag_response_info_t* response_info, size_t max_buffer_size) {
 791         // Example response, answer to MIFARE Classic read block will be 16 bytes + 2 CRC = 18 bytes
 792         // This will need the following byte array for a modulation sequence
 793         //    144        data bits (18 * 8)
 794         //     18        parity bits
 795         //      2        Start and stop
 796         //      1        Correction bit (Answer in 1172 or 1236 periods, see FPGA)
 797         //      1        just for the case
 798         // ----------- +
 799         //    166 bytes, since every bit that needs to be send costs us a byte
 800         //
 801         // Prepare the tag modulation bits from the message
 802         CodeIso14443aAsTag(response_info->response,response_info->response_n);
 803
 804         // Make sure we do not exceed the free buffer space
 805         if (ToSendMax > max_buffer_size) {
 806                 Dbprintf("Out of memory, when modulating bits for tag answer:");
 807                 Dbhexdump(response_info->response_n,response_info->response,false);
 808                 return FALSE;
 809         }
 810
 811         // Copy the byte array, used for this modulation to the buffer position
 812         memcpy(response_info->modulation,ToSend,ToSendMax);
 813
 814         // Store the number of bytes that were used for encoding/modulation and the time needed to transfer them
 815         response_info->modulation_n = ToSendMax;
 816         response_info->ProxToAirDuration = LastProxToAirDuration;
 817         return TRUE;
 818 }
 819
 820 // "precompile" responses. There are 7 predefined responses with a total of 28 bytes data to transmit.
 821 // Coded responses need one byte per bit to transfer (data, parity, start, stop, correction)
 822 // 28 * 8 data bits, 28 * 1 parity bits, 7 start bits, 7 stop bits, 7 correction bits
 823 // -> need 273 bytes buffer
 824 // 44 * 8 data bits, 44 * 1 parity bits, 9 start bits, 9 stop bits, 9 correction bits --370
 825 // 47 * 8 data bits, 47 * 1 parity bits, 10 start bits, 10 stop bits, 10 correction bits
 826 #define ALLOCATED_TAG_MODULATION_BUFFER_SIZE 453
 827
 828 bool prepare_allocated_tag_modulation(tag_response_info_t* response_info) {
 829         // Retrieve and store the current buffer index
 830         response_info->modulation = free_buffer_pointer;
 831
 832         // Determine the maximum size we can use from our buffer
 833         size_t max_buffer_size = ALLOCATED_TAG_MODULATION_BUFFER_SIZE;
 834
 835         // Forward the prepare tag modulation function to the inner function
 836         if (prepare_tag_modulation(response_info, max_buffer_size)) {
 837                 // Update the free buffer offset
 838                 free_buffer_pointer += ToSendMax;
 839                 return true;
 840         } else {
 841                 return false;
 842         }
 843 }
 844
 845 //-----------------------------------------------------------------------------
 846 // Main loop of simulated tag: receive commands from reader, decide what
 847 // response to send, and send it.
 848 // 'hf 14a sim'
 849 //-----------------------------------------------------------------------------
 850 void SimulateIso14443aTag(int tagType, int flags, byte_t* data) {
 851
 852         #define ATTACK_KEY_COUNT 8 // keep same as define in cmdhfmf.c -> readerAttack()
 853         // init pseudorand
 854         fast_prand();
 855
 856         uint8_t sak = 0;
 857         uint32_t cuid = 0;
 858         uint32_t nonce = 0;
 859
 860         // PACK response to PWD AUTH for EV1/NTAG
 861         uint8_t response8[4] = {0,0,0,0};
 862         // Counter for EV1/NTAG
 863         uint32_t counters[] = {0,0,0};
 864
 865         // The first response contains the ATQA (note: bytes are transmitted in reverse order).
 866         uint8_t response1[] = {0,0};
 867
 868         // Here, we collect CUID, block1, keytype1, NT1, NR1, AR1, CUID, block2, keytyp2, NT2, NR2, AR2
 869         // it should also collect block, keytype.
 870         uint8_t cardAUTHSC = 0;
 871         uint8_t cardAUTHKEY = 0xff;  // no authentication
 872         // allow collecting up to 8 sets of nonces to allow recovery of up to 8 keys
 873
 874         nonces_t ar_nr_nonces[ATTACK_KEY_COUNT]; // for attack types moebius
 875         memset(ar_nr_nonces, 0x00, sizeof(ar_nr_nonces));
 876         uint8_t moebius_count = 0;
 877
 878         switch (tagType) {
 879                 case 1: { // MIFARE Classic 1k
 880                         response1[0] = 0x04;
 881                         sak = 0x08;
 882                 } break;
 883                 case 2: { // MIFARE Ultralight
 884                         response1[0] = 0x44;
 885                         sak = 0x00;
 886                 } break;
 887                 case 3: { // MIFARE DESFire
 888                         response1[0] = 0x04;
 889                         response1[1] = 0x03;
 890                         sak = 0x20;
 891                 } break;
 892                 case 4: { // ISO/IEC 14443-4 - javacard (JCOP)
 893                         response1[0] = 0x04;
 894                         sak = 0x28;
 895                 } break;
 896                 case 5: { // MIFARE TNP3XXX
 897                         response1[0] = 0x01;
 898                         response1[1] = 0x0f;
 899                         sak = 0x01;
 900                 } break;
 901                 case 6: { // MIFARE Mini 320b
 902                         response1[0] = 0x44;
 903                         sak = 0x09;
 904                 } break;
 905                 case 7: { // NTAG
 906                         response1[0] = 0x44;
 907                         sak = 0x00;
 908                         // PACK
 909                         response8[0] = 0x80;
 910                         response8[1] = 0x80;
 911                         ComputeCrc14443(CRC_14443_A, response8, 2, &response8[2], &response8[3]);
 912                         // uid not supplied then get from emulator memory
 913                         if (data[0]==0) {
 914                                 uint16_t start = 4 * (0+12);
 915                                 uint8_t emdata[8];
 916                                 emlGetMemBt( emdata, start, sizeof(emdata));
 917                                 memcpy(data, emdata, 3); // uid bytes 0-2
 918                                 memcpy(data+3, emdata+4, 4); // uid bytes 3-7
 919                                 flags |= FLAG_7B_UID_IN_DATA;
 920                         }
 921                 } break;
 922                 case 8: { // MIFARE Classic 4k
 923                         response1[0] = 0x02;
 924                         sak = 0x18;
 925                 } break;
 926                 default: {
 927                         Dbprintf("Error: unkown tagtype (%d)",tagType);
 928                         return;
 929                 } break;
 930         }
 931
 932         // The second response contains the (mandatory) first 24 bits of the UID
 933         uint8_t response2[5] = {0x00};
 934
 935         // For UID size 7,
 936         uint8_t response2a[5] = {0x00};
 937
 938         if ( (flags & FLAG_7B_UID_IN_DATA) == FLAG_7B_UID_IN_DATA ) {
 939                 response2[0] = 0x88;  // Cascade Tag marker
 940                 response2[1] = data[0];
 941                 response2[2] = data[1];
 942                 response2[3] = data[2];
 943
 944                 response2a[0] = data[3];
 945                 response2a[1] = data[4];
 946                 response2a[2] = data[5];
 947                 response2a[3] = data[6]; //??
 948                 response2a[4] = response2a[0] ^ response2a[1] ^ response2a[2] ^ response2a[3];
 949
 950                 // Configure the ATQA and SAK accordingly
 951                 response1[0] |= 0x40;
 952                 sak |= 0x04;
 953
 954                 cuid = bytes_to_num(data+3, 4);
 955         } else {
 956                 memcpy(response2, data, 4);
 957                 // Configure the ATQA and SAK accordingly
 958                 response1[0] &= 0xBF;
 959                 sak &= 0xFB;
 960                 cuid = bytes_to_num(data, 4);
 961         }
 962
 963         // Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID.
 964         response2[4] = response2[0] ^ response2[1] ^ response2[2] ^ response2[3];
 965
 966         // Prepare the mandatory SAK (for 4 and 7 byte UID)
 967         uint8_t response3[3]  = {sak, 0x00, 0x00};
 968         ComputeCrc14443(CRC_14443_A, response3, 1, &response3[1], &response3[2]);
 969
 970         // Prepare the optional second SAK (for 7 byte UID), drop the cascade bit
 971         uint8_t response3a[3]  = {0x00};
 972         response3a[0] = sak & 0xFB;
 973         ComputeCrc14443(CRC_14443_A, response3a, 1, &response3a[1], &response3a[2]);
 974
 975         // Tag NONCE.
 976         uint8_t response5[4];
 977
 978         uint8_t response6[] = { 0x04, 0x58, 0x80, 0x02, 0x00, 0x00 };   // dummy ATS (pseudo-ATR), answer to RATS:
 979         // Format byte = 0x58: FSCI=0x08 (FSC=256), TA(1) and TC(1) present,
 980         // TA(1) = 0x80: different divisors not supported, DR = 1, DS = 1
 981         // 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)
 982         // TC(1) = 0x02: CID supported, NAD not supported
 983         ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]);
 984
 985         // Prepare GET_VERSION (different for UL EV-1 / NTAG)
 986         // uint8_t response7_EV1[] = {0x00, 0x04, 0x03, 0x01, 0x01, 0x00, 0x0b, 0x03, 0xfd, 0xf7};  //EV1 48bytes VERSION.
 987         // uint8_t response7_NTAG[] = {0x00, 0x04, 0x04, 0x02, 0x01, 0x00, 0x11, 0x03, 0x01, 0x9e}; //NTAG 215
 988         // Prepare CHK_TEARING
 989         // uint8_t response9[] =  {0xBD,0x90,0x3f};
 990
 991         #define TAG_RESPONSE_COUNT 10
 992         tag_response_info_t responses[TAG_RESPONSE_COUNT] = {
 993                 { .response = response1,  .response_n = sizeof(response1)  },  // Answer to request - respond with card type
 994                 { .response = response2,  .response_n = sizeof(response2)  },  // Anticollision cascade1 - respond with uid
 995                 { .response = response2a, .response_n = sizeof(response2a) },  // Anticollision cascade2 - respond with 2nd half of uid if asked
 996                 { .response = response3,  .response_n = sizeof(response3)  },  // Acknowledge select - cascade 1
 997                 { .response = response3a, .response_n = sizeof(response3a) },  // Acknowledge select - cascade 2
 998                 { .response = response5,  .response_n = sizeof(response5)  },  // Authentication answer (random nonce)
 999                 { .response = response6,  .response_n = sizeof(response6)  },  // dummy ATS (pseudo-ATR), answer to RATS
1000
1001                 { .response = response8,   .response_n = sizeof(response8) }  // EV1/NTAG PACK response
1002         };
1003                 // { .response = response7_NTAG, .response_n = sizeof(response7_NTAG)}, // EV1/NTAG GET_VERSION response
1004                 // { .response = response9,      .response_n = sizeof(response9)     }  // EV1/NTAG CHK_TEAR response
1005
1006
1007         // Allocate 512 bytes for the dynamic modulation, created when the reader queries for it
1008         // Such a response is less time critical, so we can prepare them on the fly
1009         #define DYNAMIC_RESPONSE_BUFFER_SIZE 64
1010         #define DYNAMIC_MODULATION_BUFFER_SIZE 512
1011         uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
1012         uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
1013         tag_response_info_t dynamic_response_info = {
1014                 .response = dynamic_response_buffer,
1015                 .response_n = 0,
1016                 .modulation = dynamic_modulation_buffer,
1017                 .modulation_n = 0
1018         };
1019
1020         // We need to listen to the high-frequency, peak-detected path.
1021         iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1022
1023         BigBuf_free_keep_EM();
1024         clear_trace();
1025         set_tracing(TRUE);
1026
1027         // allocate buffers:
1028         uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
1029         uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
1030         free_buffer_pointer = BigBuf_malloc(ALLOCATED_TAG_MODULATION_BUFFER_SIZE);
1031
1032         // Prepare the responses of the anticollision phase
1033         // there will be not enough time to do this at the moment the reader sends it REQA
1034         for (size_t i=0; i<TAG_RESPONSE_COUNT; i++)
1035                 prepare_allocated_tag_modulation(&responses[i]);
1036
1037         int len = 0;
1038
1039         // To control where we are in the protocol
1040         int order = 0;
1041         int lastorder;
1042
1043         // Just to allow some checks
1044         int happened = 0;
1045         int happened2 = 0;
1046         int cmdsRecvd = 0;
1047         tag_response_info_t* p_response;
1048
1049         LED_A_ON();
1050         for(;;) {
1051                 WDT_HIT();
1052
1053                 // Clean receive command buffer
1054                 if(!GetIso14443aCommandFromReader(receivedCmd, receivedCmdPar, &len)) {
1055                         Dbprintf("Emulator stopped. Tracing: %d  trace length: %d ", tracing, BigBuf_get_traceLen());
1056                         break;
1057                 }
1058                 p_response = NULL;
1059
1060                 // Okay, look at the command now.
1061                 lastorder = order;
1062                 if(receivedCmd[0] == ISO14443A_CMD_REQA) { // Received a REQUEST
1063                         p_response = &responses[0]; order = 1;
1064                 } else if(receivedCmd[0] == ISO14443A_CMD_WUPA) { // Received a WAKEUP
1065                         p_response = &responses[0]; order = 6;
1066                 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT) {       // Received request for UID (cascade 1)
1067                         p_response = &responses[1]; order = 2;
1068                 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_2) {     // Received request for UID (cascade 2)
1069                         p_response = &responses[2]; order = 20;
1070                 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT) {       // Received a SELECT (cascade 1)
1071                         p_response = &responses[3]; order = 3;
1072                 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_2) {     // Received a SELECT (cascade 2)
1073                         p_response = &responses[4]; order = 30;
1074                 } else if(receivedCmd[0] == ISO14443A_CMD_READBLOCK) {  // Received a (plain) READ
1075                         uint8_t block = receivedCmd[1];
1076                         // if Ultralight or NTAG (4 byte blocks)
1077                         if ( tagType == 7 || tagType == 2 ) {
1078                                 // first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1079                                 uint16_t start = 4 * (block+12);
1080                                 uint8_t emdata[MAX_MIFARE_FRAME_SIZE];
1081                                 emlGetMemBt( emdata, start, 16);
1082                                 AppendCrc14443a(emdata, 16);
1083                                 EmSendCmd(emdata, sizeof(emdata));
1084                                 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1085                                 p_response = NULL;
1086                         } else { // all other tags (16 byte block tags)
1087                                 uint8_t emdata[MAX_MIFARE_FRAME_SIZE];
1088                                 emlGetMemBt( emdata, block, 16);
1089                                 AppendCrc14443a(emdata, 16);
1090                                 EmSendCmd(emdata, sizeof(emdata));
1091                                 // EmSendCmd(data+(4*receivedCmd[1]),16);
1092                                 // Dbprintf("Read request from reader: %x %x",receivedCmd[0],receivedCmd[1]);
1093                                 // We already responded, do not send anything with the EmSendCmd14443aRaw() that is called below
1094                                 p_response = NULL;
1095                         }
1096                 } else if(receivedCmd[0] == MIFARE_ULEV1_FASTREAD) {    // Received a FAST READ (ranged read)
1097                         uint8_t emdata[MAX_FRAME_SIZE];
1098                         // first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1099                         int start =  (receivedCmd[1]+12) * 4;
1100                         int len   = (receivedCmd[2] - receivedCmd[1] + 1) * 4;
1101                         emlGetMemBt( emdata, start, len);
1102                         AppendCrc14443a(emdata, len);
1103                         EmSendCmd(emdata, len+2);
1104                         p_response = NULL;
1105                 } else if(receivedCmd[0] == MIFARE_ULEV1_READSIG && tagType == 7) {     // Received a READ SIGNATURE --
1106                         // first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1107                         uint16_t start = 4 * 4;
1108                         uint8_t emdata[34];
1109                         emlGetMemBt( emdata, start, 32);
1110                         AppendCrc14443a(emdata, 32);
1111                         EmSendCmd(emdata, sizeof(emdata));
1112                         p_response = NULL;
1113                 } else if (receivedCmd[0] == MIFARE_ULEV1_READ_CNT && tagType == 7) {   // Received a READ COUNTER --
1114                         uint8_t index = receivedCmd[1];
1115                         uint8_t cmd[] =  {0x00,0x00,0x00,0x14,0xa5};
1116                         if ( counters[index] > 0) {
1117                                 num_to_bytes(counters[index], 3, cmd);
1118                                 AppendCrc14443a(cmd, sizeof(cmd)-2);
1119                         }
1120                         EmSendCmd(cmd,sizeof(cmd));
1121                         p_response = NULL;
1122                 } else if (receivedCmd[0] == MIFARE_ULEV1_INCR_CNT && tagType == 7) {   // Received a INC COUNTER --
1123                         // number of counter
1124                         uint8_t counter = receivedCmd[1];
1125                         uint32_t val = bytes_to_num(receivedCmd+2,4);
1126                         counters[counter] = val;
1127
1128                         // send ACK
1129                         uint8_t ack[] = {0x0a};
1130                         EmSendCmd(ack,sizeof(ack));
1131                         p_response = NULL;
1132                 } else if(receivedCmd[0] == MIFARE_ULEV1_CHECKTEAR && tagType == 7) {   // Received a CHECK_TEARING_EVENT --
1133                         // first 12 blocks of emu are [getversion answer - check tearing - pack - 0x00 - signature]
1134                         uint8_t emdata[3];
1135                         uint8_t counter=0;
1136                         if (receivedCmd[1]<3) counter = receivedCmd[1];
1137                         emlGetMemBt( emdata, 10+counter, 1);
1138                         AppendCrc14443a(emdata, sizeof(emdata)-2);
1139                         EmSendCmd(emdata, sizeof(emdata));
1140                         p_response = NULL;
1141                 } else if(receivedCmd[0] == ISO14443A_CMD_HALT) {       // Received a HALT
1142                         LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1143                         p_response = NULL;
1144                 } else if(receivedCmd[0] == MIFARE_AUTH_KEYA || receivedCmd[0] == MIFARE_AUTH_KEYB) {   // Received an authentication request
1145                         if ( tagType == 7 ) {   // IF NTAG /EV1  0x60 == GET_VERSION, not a authentication request.
1146                                 uint8_t emdata[10];
1147                                 emlGetMemBt( emdata, 0, 8 );
1148                                 AppendCrc14443a(emdata, sizeof(emdata)-2);
1149                                 EmSendCmd(emdata, sizeof(emdata));
1150                                 p_response = NULL;
1151                         } else {
1152
1153                                 cardAUTHKEY = receivedCmd[0] - 0x60;
1154                                 cardAUTHSC = receivedCmd[1] / 4; // received block num
1155
1156                                 // incease nonce at AUTH requests. this is time consuming.
1157                                 nonce = prand();
1158                                 //num_to_bytes(nonce, 4, response5);
1159                                 num_to_bytes(nonce, 4, dynamic_response_info.response);
1160                                 dynamic_response_info.response_n = 4;
1161
1162                                 //prepare_tag_modulation(&responses[5], DYNAMIC_MODULATION_BUFFER_SIZE);
1163                                 prepare_tag_modulation(&dynamic_response_info, DYNAMIC_MODULATION_BUFFER_SIZE);
1164                                 p_response = &dynamic_response_info;
1165                                 //p_response = &responses[5];
1166                                 order = 7;
1167                         }
1168                 } else if(receivedCmd[0] == ISO14443A_CMD_RATS) {       // Received a RATS request
1169                         if (tagType == 1 || tagType == 2) {     // RATS not supported
1170                                 EmSend4bit(CARD_NACK_NA);
1171                                 p_response = NULL;
1172                         } else {
1173                                 p_response = &responses[6]; order = 70;
1174                         }
1175                 } else if (order == 7 && len == 8) { // Received {nr] and {ar} (part of authentication)
1176                         LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1177                         uint32_t nr = bytes_to_num(receivedCmd,4);
1178                         uint32_t ar = bytes_to_num(receivedCmd+4,4);
1179
1180                         // Collect AR/NR per keytype & sector
1181                         if ( (flags & FLAG_NR_AR_ATTACK) == FLAG_NR_AR_ATTACK ) {
1182
1183                                 int8_t index = -1;
1184                                 int8_t empty = -1;
1185                                 for (uint8_t i = 0; i < ATTACK_KEY_COUNT; i++) {
1186                                         // find which index to use
1187                                         if ( (cardAUTHSC == ar_nr_nonces[i].sector) &&  (cardAUTHKEY == ar_nr_nonces[i].keytype))
1188                                                 index = i;
1189
1190                                         // keep track of empty slots.
1191                                         if ( ar_nr_nonces[i].state == EMPTY)
1192                                                 empty = i;
1193                                 }
1194                                 // if no empty slots.  Choose first and overwrite.
1195                                 if ( index == -1 ) {
1196                                         if ( empty == -1 ) {
1197                                                 index = 0;
1198                                                 ar_nr_nonces[index].state = EMPTY;
1199                                         } else {
1200                                                 index = empty;
1201                                         }
1202                                 }
1203
1204                                 switch(ar_nr_nonces[index].state) {
1205                                         case EMPTY: {
1206                                                 // first nonce collect
1207                                                 ar_nr_nonces[index].cuid = cuid;
1208                                                 ar_nr_nonces[index].sector = cardAUTHSC;
1209                                                 ar_nr_nonces[index].keytype = cardAUTHKEY;
1210                                                 ar_nr_nonces[index].nonce = nonce;
1211                                                 ar_nr_nonces[index].nr = nr;
1212                                                 ar_nr_nonces[index].ar = ar;
1213                                                 ar_nr_nonces[index].state = FIRST;
1214                                                 break;
1215                                         }
1216                                         case FIRST : {
1217                                                 // second nonce collect
1218                                                 ar_nr_nonces[index].nonce2 = nonce;
1219                                                 ar_nr_nonces[index].nr2 = nr;
1220                                                 ar_nr_nonces[index].ar2 = ar;
1221                                                 ar_nr_nonces[index].state = SECOND;
1222
1223                                                 // send to client
1224                                                 cmd_send(CMD_ACK, CMD_SIMULATE_MIFARE_CARD, 0, 0, &ar_nr_nonces[index], sizeof(nonces_t));
1225
1226                                                 ar_nr_nonces[index].state = EMPTY;
1227                                                 ar_nr_nonces[index].sector = 0;
1228                                                 ar_nr_nonces[index].keytype = 0;
1229
1230                                                 moebius_count++;
1231                                                 break;
1232                                         }
1233                                         default: break;
1234                                 }
1235                         }
1236                         p_response = NULL;
1237
1238                 } else if (receivedCmd[0] == MIFARE_ULC_AUTH_1 ) { // ULC authentication, or Desfire Authentication
1239                 } else if (receivedCmd[0] == MIFARE_ULEV1_AUTH) { // NTAG / EV-1 authentication
1240                         if ( tagType == 7 ) {
1241                                 uint16_t start = 13; // first 4 blocks of emu are [getversion answer - check tearing - pack - 0x00]
1242                                 uint8_t emdata[4];
1243                                 emlGetMemBt( emdata, start, 2);
1244                                 AppendCrc14443a(emdata, 2);
1245                                 EmSendCmd(emdata, sizeof(emdata));
1246                                 p_response = NULL;
1247                                 uint32_t pwd = bytes_to_num(receivedCmd+1,4);
1248
1249                                 if ( MF_DBGLEVEL >= 3) Dbprintf("Auth attempt: %08x", pwd);
1250                         }
1251                 } else {
1252                         // Check for ISO 14443A-4 compliant commands, look at left nibble
1253                         switch (receivedCmd[0]) {
1254                                 case 0x02:
1255                                 case 0x03: {  // IBlock (command no CID)
1256                                         dynamic_response_info.response[0] = receivedCmd[0];
1257                                         dynamic_response_info.response[1] = 0x90;
1258                                         dynamic_response_info.response[2] = 0x00;
1259                                         dynamic_response_info.response_n = 3;
1260                                 } break;
1261                                 case 0x0B:
1262                                 case 0x0A: { // IBlock (command CID)
1263                                   dynamic_response_info.response[0] = receivedCmd[0];
1264                                   dynamic_response_info.response[1] = 0x00;
1265                                   dynamic_response_info.response[2] = 0x90;
1266                                   dynamic_response_info.response[3] = 0x00;
1267                                   dynamic_response_info.response_n = 4;
1268                                 } break;
1269
1270                                 case 0x1A:
1271                                 case 0x1B: { // Chaining command
1272                                   dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1);
1273                                   dynamic_response_info.response_n = 2;
1274                                 } break;
1275
1276                                 case 0xAA:
1277                                 case 0xBB: {
1278                                   dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11;
1279                                   dynamic_response_info.response_n = 2;
1280                                 } break;
1281
1282                                 case 0xBA: { // ping / pong
1283                                         dynamic_response_info.response[0] = 0xAB;
1284                                         dynamic_response_info.response[1] = 0x00;
1285                                         dynamic_response_info.response_n = 2;
1286                                 } break;
1287
1288                                 case 0xCA:
1289                                 case 0xC2: { // Readers sends deselect command
1290                                         dynamic_response_info.response[0] = 0xCA;
1291                                         dynamic_response_info.response[1] = 0x00;
1292                                         dynamic_response_info.response_n = 2;
1293                                 } break;
1294
1295                                 default: {
1296                                         // Never seen this command before
1297                                         LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1298                                         Dbprintf("Received unknown command (len=%d):",len);
1299                                         Dbhexdump(len,receivedCmd,false);
1300                                         // Do not respond
1301                                         dynamic_response_info.response_n = 0;
1302                                 } break;
1303                         }
1304
1305                         if (dynamic_response_info.response_n > 0) {
1306                                 // Copy the CID from the reader query
1307                                 dynamic_response_info.response[1] = receivedCmd[1];
1308
1309                                 // Add CRC bytes, always used in ISO 14443A-4 compliant cards
1310                                 AppendCrc14443a(dynamic_response_info.response, dynamic_response_info.response_n);
1311                                 dynamic_response_info.response_n += 2;
1312
1313                                 if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) {
1314                                         DbpString("Error preparing tag response");
1315                                         LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
1316                                         break;
1317                                 }
1318                                 p_response = &dynamic_response_info;
1319                         }
1320                 }
1321
1322                 // Count number of wakeups received after a halt
1323                 if(order == 6 && lastorder == 5) { happened++; }
1324
1325                 // Count number of other messages after a halt
1326                 if(order != 6 && lastorder == 5) { happened2++; }
1327
1328                 // comment this limit if you want to simulation longer
1329                 if (!tracing) {
1330                         DbpString("Trace Full. Simulation stopped.");
1331                         break;
1332                 }
1333                 // comment this limit if you want to simulation longer
1334                 if(cmdsRecvd > 999) {
1335                         DbpString("1000 commands later...");
1336                         break;
1337                 }
1338                 cmdsRecvd++;
1339
1340                 if (p_response != NULL) {
1341                         EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n);
1342                         // do the tracing for the previous reader request and this tag answer:
1343                         uint8_t par[MAX_PARITY_SIZE] = {0x00};
1344                         GetParity(p_response->response, p_response->response_n, par);
1345
1346                         EmLogTrace(Uart.output,
1347                                                 Uart.len,
1348                                                 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1349                                                 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1350                                                 Uart.parity,
1351                                                 p_response->response,
1352                                                 p_response->response_n,
1353                                                 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1354                                                 (LastTimeProxToAirStart + p_response->ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1355                                                 par);
1356                 }
1357         }
1358
1359         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
1360         set_tracing(FALSE);
1361         BigBuf_free_keep_EM();
1362         LED_A_OFF();
1363
1364         if (MF_DBGLEVEL >= 4){
1365                 Dbprintf("-[ Wake ups after halt  [%d]", happened);
1366                 Dbprintf("-[ Messages after halt  [%d]", happened2);
1367                 Dbprintf("-[ Num of received cmd  [%d]", cmdsRecvd);
1368                 Dbprintf("-[ Num of moebius tries [%d]", moebius_count);
1369         }
1370
1371         cmd_send(CMD_ACK,1,0,0,0,0);
1372 }
1373
1374 // prepare a delayed transfer. This simply shifts ToSend[] by a number
1375 // of bits specified in the delay parameter.
1376 void PrepareDelayedTransfer(uint16_t delay) {
1377         delay &= 0x07;
1378         if (!delay) return;
1379
1380         uint8_t bitmask = 0;
1381         uint8_t bits_to_shift = 0;
1382         uint8_t bits_shifted = 0;
1383         uint16_t i = 0;
1384
1385         for (i = 0; i < delay; ++i)
1386                 bitmask |= (0x01 << i);
1387
1388         ToSend[++ToSendMax] = 0x00;
1389
1390         for (i = 0; i < ToSendMax; ++i) {
1391                         bits_to_shift = ToSend[i] & bitmask;
1392                         ToSend[i] = ToSend[i] >> delay;
1393                         ToSend[i] = ToSend[i] | (bits_shifted << (8 - delay));
1394                         bits_shifted = bits_to_shift;
1395                 }
1396         }
1397
1398
1399 //-------------------------------------------------------------------------------------
1400 // Transmit the command (to the tag) that was placed in ToSend[].
1401 // Parameter timing:
1402 // if NULL: transfer at next possible time, taking into account
1403 //                      request guard time and frame delay time
1404 // if == 0:     transfer immediately and return time of transfer
1405 // if != 0: delay transfer until time specified
1406 //-------------------------------------------------------------------------------------
1407 static void TransmitFor14443a(const uint8_t *cmd, uint16_t len, uint32_t *timing) {
1408         FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_MOD);
1409
1410         uint32_t ThisTransferTime = 0;
1411
1412         if (timing) {
1413                 if(*timing == 0) {                                                                              // Measure time
1414                         *timing = (GetCountSspClk() + 8) & 0xfffffff8;
1415                 } else {
1416                         PrepareDelayedTransfer(*timing & 0x00000007);           // Delay transfer (fine tuning - up to 7 MF clock ticks)
1417                 }
1418                 if(MF_DBGLEVEL >= 4 && GetCountSspClk() >= (*timing & 0xfffffff8)) Dbprintf("TransmitFor14443a: Missed timing");
1419                 while(GetCountSspClk() < (*timing & 0xfffffff8));               // Delay transfer (multiple of 8 MF clock ticks)
1420                 LastTimeProxToAirStart = *timing;
1421         } else {
1422                 ThisTransferTime = ((MAX(NextTransferTime, GetCountSspClk()) & 0xfffffff8) + 8);
1423
1424                 while(GetCountSspClk() < ThisTransferTime);
1425
1426                 LastTimeProxToAirStart = ThisTransferTime;
1427         }
1428
1429         // clear TXRDY
1430         AT91C_BASE_SSC->SSC_THR = SEC_Y;
1431
1432         uint16_t c = 0;
1433         for(;;) {
1434                 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1435                         AT91C_BASE_SSC->SSC_THR = cmd[c];
1436                         ++c;
1437                         if(c >= len)
1438                                 break;
1439                 }
1440         }
1441
1442         NextTransferTime = MAX(NextTransferTime, LastTimeProxToAirStart + REQUEST_GUARD_TIME);
1443 }
1444
1445 //-----------------------------------------------------------------------------
1446 // Prepare reader command (in bits, support short frames) to send to FPGA
1447 //-----------------------------------------------------------------------------
1448 void CodeIso14443aBitsAsReaderPar(const uint8_t *cmd, uint16_t bits, const uint8_t *parity) {
1449         int i, j;
1450         int last = 0;
1451         uint8_t b;
1452
1453         ToSendReset();
1454
1455         // Start of Communication (Seq. Z)
1456         ToSend[++ToSendMax] = SEC_Z;
1457         LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1458
1459         size_t bytecount = nbytes(bits);
1460         // Generate send structure for the data bits
1461         for (i = 0; i < bytecount; i++) {
1462                 // Get the current byte to send
1463                 b = cmd[i];
1464                 size_t bitsleft = MIN((bits-(i*8)),8);
1465
1466                 for (j = 0; j < bitsleft; j++) {
1467                         if (b & 1) {
1468                                 // Sequence X
1469                                 ToSend[++ToSendMax] = SEC_X;
1470                                 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1471                                 last = 1;
1472                         } else {
1473                                 if (last == 0) {
1474                                 // Sequence Z
1475                                 ToSend[++ToSendMax] = SEC_Z;
1476                                 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1477                                 } else {
1478                                         // Sequence Y
1479                                         ToSend[++ToSendMax] = SEC_Y;
1480                                         last = 0;
1481                                 }
1482                         }
1483                         b >>= 1;
1484                 }
1485
1486                 // Only transmit parity bit if we transmitted a complete byte
1487                 if (j == 8 && parity != NULL) {
1488                         // Get the parity bit
1489                         if (parity[i>>3] & (0x80 >> (i&0x0007))) {
1490                                 // Sequence X
1491                                 ToSend[++ToSendMax] = SEC_X;
1492                                 LastProxToAirDuration = 8 * (ToSendMax+1) - 2;
1493                                 last = 1;
1494                         } else {
1495                                 if (last == 0) {
1496                                         // Sequence Z
1497                                         ToSend[++ToSendMax] = SEC_Z;
1498                                         LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1499                                 } else {
1500                                         // Sequence Y
1501                                         ToSend[++ToSendMax] = SEC_Y;
1502                                         last = 0;
1503                                 }
1504                         }
1505                 }
1506         }
1507
1508         // End of Communication: Logic 0 followed by Sequence Y
1509         if (last == 0) {
1510                 // Sequence Z
1511                 ToSend[++ToSendMax] = SEC_Z;
1512                 LastProxToAirDuration = 8 * (ToSendMax+1) - 6;
1513         } else {
1514                 // Sequence Y
1515                 ToSend[++ToSendMax] = SEC_Y;
1516                 last = 0;
1517         }
1518         ToSend[++ToSendMax] = SEC_Y;
1519
1520         // Convert to length of command:
1521         ++ToSendMax;
1522 }
1523
1524 //-----------------------------------------------------------------------------
1525 // Prepare reader command to send to FPGA
1526 //-----------------------------------------------------------------------------
1527 void CodeIso14443aAsReaderPar(const uint8_t *cmd, uint16_t len, const uint8_t *parity) {
1528   CodeIso14443aBitsAsReaderPar(cmd, len*8, parity);
1529 }
1530
1531 //-----------------------------------------------------------------------------
1532 // Wait for commands from reader
1533 // Stop when button is pressed (return 1) or field was gone (return 2)
1534 // Or return 0 when command is captured
1535 //-----------------------------------------------------------------------------
1536 int EmGetCmd(uint8_t *received, uint16_t *len, uint8_t *parity) {
1537         *len = 0;
1538
1539         uint32_t timer = 0, vtime = 0;
1540         int analogCnt = 0;
1541         int analogAVG = 0;
1542
1543         // Set FPGA mode to "simulated ISO 14443 tag", no modulation (listen
1544         // only, since we are receiving, not transmitting).
1545         // Signal field is off with the appropriate LED
1546         LED_D_OFF();
1547         FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_LISTEN);
1548
1549         // Set ADC to read field strength
1550         AT91C_BASE_ADC->ADC_CR = AT91C_ADC_SWRST;
1551         AT91C_BASE_ADC->ADC_MR =
1552                                 ADC_MODE_PRESCALE(63) |
1553                                 ADC_MODE_STARTUP_TIME(1) |
1554                                 ADC_MODE_SAMPLE_HOLD_TIME(15);
1555         AT91C_BASE_ADC->ADC_CHER = ADC_CHANNEL(ADC_CHAN_HF);
1556         // start ADC
1557         AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1558
1559         // Now run a 'software UART' on the stream of incoming samples.
1560         UartInit(received, parity);
1561
1562         // Clear RXRDY:
1563     uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1564
1565         for(;;) {
1566                 WDT_HIT();
1567
1568                 if (BUTTON_PRESS()) return 1;
1569
1570                 // test if the field exists
1571                 if (AT91C_BASE_ADC->ADC_SR & ADC_END_OF_CONVERSION(ADC_CHAN_HF)) {
1572                         analogCnt++;
1573                         analogAVG += AT91C_BASE_ADC->ADC_CDR[ADC_CHAN_HF];
1574                         AT91C_BASE_ADC->ADC_CR = AT91C_ADC_START;
1575                         if (analogCnt >= 32) {
1576                                 if ((MAX_ADC_HF_VOLTAGE * (analogAVG / analogCnt) >> 10) < MF_MINFIELDV) {
1577                                         vtime = GetTickCount();
1578                                         if (!timer) timer = vtime;
1579                                         // 50ms no field --> card to idle state
1580                                         if (vtime - timer > 50) return 2;
1581                                 } else
1582                                         if (timer) timer = 0;
1583                                 analogCnt = 0;
1584                                 analogAVG = 0;
1585                         }
1586                 }
1587
1588                 // receive and test the miller decoding
1589         if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1590             b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1591                         if(MillerDecoding(b, 0)) {
1592                                 *len = Uart.len;
1593                                 return 0;
1594                         }
1595         }
1596         }
1597 }
1598
1599 int EmSendCmd14443aRaw(uint8_t *resp, uint16_t respLen) {
1600         uint8_t b;
1601         uint16_t i = 0;
1602         uint32_t ThisTransferTime;
1603         bool correctionNeeded;
1604
1605         // Modulate Manchester
1606         FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_TAGSIM_MOD);
1607
1608         // Include correction bit if necessary
1609         if (Uart.bitCount == 7)
1610         {
1611                 // Short tags (7 bits) don't have parity, determine the correct value from MSB
1612                 correctionNeeded = Uart.output[0] & 0x40;
1613         }
1614         else
1615         {
1616                 // The parity bits are left-aligned
1617                 correctionNeeded = Uart.parity[(Uart.len-1)/8] & (0x80 >> ((Uart.len-1) & 7));
1618         }
1619         // 1236, so correction bit needed
1620         i = (correctionNeeded) ? 0 : 1;
1621
1622         // clear receiving shift register and holding register
1623         while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1624         b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1625         while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1626         b = AT91C_BASE_SSC->SSC_RHR; (void) b;
1627
1628         // wait for the FPGA to signal fdt_indicator == 1 (the FPGA is ready to queue new data in its delay line)
1629         for (uint8_t j = 0; j < 5; j++) {       // allow timeout - better late than never
1630                 while(!(AT91C_BASE_SSC->SSC_SR & AT91C_SSC_RXRDY));
1631                 if (AT91C_BASE_SSC->SSC_RHR) break;
1632         }
1633
1634         while ((ThisTransferTime = GetCountSspClk()) & 0x00000007);
1635
1636         // Clear TXRDY:
1637         AT91C_BASE_SSC->SSC_THR = SEC_F;
1638
1639         // send cycle
1640         for(; i < respLen; ) {
1641                 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1642                         AT91C_BASE_SSC->SSC_THR = resp[i++];
1643                         FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1644                 }
1645
1646                 if(BUTTON_PRESS()) break;
1647         }
1648
1649         // Ensure that the FPGA Delay Queue is empty before we switch to TAGSIM_LISTEN again:
1650         uint8_t fpga_queued_bits = FpgaSendQueueDelay >> 3;  // twich /8 ??   >>3,
1651         for (i = 0; i <= fpga_queued_bits/8 + 1; ) {
1652                 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_TXRDY)) {
1653                         AT91C_BASE_SSC->SSC_THR = SEC_F;
1654                         FpgaSendQueueDelay = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1655                         i++;
1656                 }
1657         }
1658         LastTimeProxToAirStart = ThisTransferTime + (correctionNeeded ? 8 : 0);
1659         return 0;
1660 }
1661
1662 int EmSend4bit(uint8_t resp){
1663         Code4bitAnswerAsTag(resp);
1664         int res = EmSendCmd14443aRaw(ToSend, ToSendMax);
1665         // do the tracing for the previous reader request and this tag answer:
1666         uint8_t par[1] = {0x00};
1667         GetParity(&resp, 1, par);
1668         EmLogTrace(Uart.output,
1669                                 Uart.len,
1670                                 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1671                                 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1672                                 Uart.parity,
1673                                 &resp,
1674                                 1,
1675                                 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1676                                 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1677                                 par);
1678         return res;
1679 }
1680
1681 int EmSendCmdPar(uint8_t *resp, uint16_t respLen, uint8_t *par){
1682         CodeIso14443aAsTagPar(resp, respLen, par);
1683         int res = EmSendCmd14443aRaw(ToSend, ToSendMax);
1684         // do the tracing for the previous reader request and this tag answer:
1685         EmLogTrace(Uart.output,
1686                                 Uart.len,
1687                                 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
1688                                 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
1689                                 Uart.parity,
1690                                 resp,
1691                                 respLen,
1692                                 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
1693                                 (LastTimeProxToAirStart + LastProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
1694                                 par);
1695         return res;
1696 }
1697
1698 int EmSendCmd(uint8_t *resp, uint16_t respLen){
1699         uint8_t par[MAX_PARITY_SIZE] = {0x00};
1700         GetParity(resp, respLen, par);
1701         return EmSendCmdPar(resp, respLen, par);
1702 }
1703
1704 bool EmLogTrace(uint8_t *reader_data, uint16_t reader_len, uint32_t reader_StartTime, uint32_t reader_EndTime, uint8_t *reader_Parity,
1705                                  uint8_t *tag_data, uint16_t tag_len, uint32_t tag_StartTime, uint32_t tag_EndTime, uint8_t *tag_Parity)
1706 {
1707         // we cannot exactly measure the end and start of a received command from reader. However we know that the delay from
1708         // end of the received command to start of the tag's (simulated by us) answer is n*128+20 or n*128+84 resp.
1709         // with n >= 9. The start of the tags answer can be measured and therefore the end of the received command be calculated:
1710         uint16_t reader_modlen = reader_EndTime - reader_StartTime;
1711         uint16_t approx_fdt = tag_StartTime - reader_EndTime;
1712         uint16_t exact_fdt = (approx_fdt - 20 + 32)/64 * 64 + 20;
1713         reader_EndTime = tag_StartTime - exact_fdt;
1714         reader_StartTime = reader_EndTime - reader_modlen;
1715
1716         if (!LogTrace(reader_data, reader_len, reader_StartTime, reader_EndTime, reader_Parity, TRUE))
1717                 return FALSE;
1718         else
1719                 return(!LogTrace(tag_data, tag_len, tag_StartTime, tag_EndTime, tag_Parity, FALSE));
1720
1721 }
1722
1723 //-----------------------------------------------------------------------------
1724 // Wait a certain time for tag response
1725 //  If a response is captured return TRUE
1726 //  If it takes too long return FALSE
1727 //-----------------------------------------------------------------------------
1728 static int GetIso14443aAnswerFromTag(uint8_t *receivedResponse, uint8_t *receivedResponsePar, uint16_t offset) {
1729         uint32_t c = 0x00;
1730
1731         // Set FPGA mode to "reader listen mode", no modulation (listen
1732         // only, since we are receiving, not transmitting).
1733         // Signal field is on with the appropriate LED
1734         LED_D_ON();
1735         FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | FPGA_HF_ISO14443A_READER_LISTEN);
1736
1737         // Now get the answer from the card
1738         DemodInit(receivedResponse, receivedResponsePar);
1739
1740         // clear RXRDY:
1741     uint8_t b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1742
1743         for(;;) {
1744                 WDT_HIT();
1745
1746                 if(AT91C_BASE_SSC->SSC_SR & (AT91C_SSC_RXRDY)) {
1747                         b = (uint8_t)AT91C_BASE_SSC->SSC_RHR;
1748                         if(ManchesterDecoding(b, offset, 0)) {
1749                                 NextTransferTime = MAX(NextTransferTime, Demod.endTime - (DELAY_AIR2ARM_AS_READER + DELAY_ARM2AIR_AS_READER)/16 + FRAME_DELAY_TIME_PICC_TO_PCD);
1750                                 return TRUE;
1751                         } else if (c++ > iso14a_timeout && Demod.state == DEMOD_UNSYNCD) {
1752                                 return FALSE;
1753                         }
1754                 }
1755         }
1756 }
1757
1758 void ReaderTransmitBitsPar(uint8_t* frame, uint16_t bits, uint8_t *par, uint32_t *timing) {
1759
1760         CodeIso14443aBitsAsReaderPar(frame, bits, par);
1761         // Send command to tag
1762         TransmitFor14443a(ToSend, ToSendMax, timing);
1763         if(trigger) LED_A_ON();
1764
1765         LogTrace(frame, nbytes(bits), (LastTimeProxToAirStart<<4) + DELAY_ARM2AIR_AS_READER, ((LastTimeProxToAirStart + LastProxToAirDuration)<<4) + DELAY_ARM2AIR_AS_READER, par, TRUE);
1766 }
1767
1768 void ReaderTransmitPar(uint8_t* frame, uint16_t len, uint8_t *par, uint32_t *timing) {
1769   ReaderTransmitBitsPar(frame, len*8, par, timing);
1770 }
1771
1772 void ReaderTransmitBits(uint8_t* frame, uint16_t len, uint32_t *timing) {
1773         // Generate parity and redirect
1774         uint8_t par[MAX_PARITY_SIZE] = {0x00};
1775         GetParity(frame, len/8, par);
1776         ReaderTransmitBitsPar(frame, len, par, timing);
1777 }
1778
1779 void ReaderTransmit(uint8_t* frame, uint16_t len, uint32_t *timing) {
1780         // Generate parity and redirect
1781         uint8_t par[MAX_PARITY_SIZE] = {0x00};
1782         GetParity(frame, len, par);
1783         ReaderTransmitBitsPar(frame, len*8, par, timing);
1784 }
1785
1786 int ReaderReceiveOffset(uint8_t* receivedAnswer, uint16_t offset, uint8_t *parity) {
1787         if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, offset))
1788                 return FALSE;
1789         LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1790         return Demod.len;
1791 }
1792
1793 int ReaderReceive(uint8_t *receivedAnswer, uint8_t *parity) {
1794         if (!GetIso14443aAnswerFromTag(receivedAnswer, parity, 0))
1795                 return FALSE;
1796         LogTrace(receivedAnswer, Demod.len, Demod.startTime*16 - DELAY_AIR2ARM_AS_READER, Demod.endTime*16 - DELAY_AIR2ARM_AS_READER, parity, FALSE);
1797         return Demod.len;
1798 }
1799
1800 // performs iso14443a anticollision (optional) and card select procedure
1801 // fills the uid and cuid pointer unless NULL
1802 // fills the card info record unless NULL
1803 // if anticollision is false, then the UID must be provided in uid_ptr[]
1804 // and num_cascades must be set (1: 4 Byte UID, 2: 7 Byte UID, 3: 10 Byte UID)
1805 int iso14443a_select_card(byte_t *uid_ptr, iso14a_card_select_t *p_hi14a_card, uint32_t *cuid_ptr, bool anticollision, uint8_t num_cascades) {
1806         uint8_t wupa[]       = { ISO14443A_CMD_WUPA };  // 0x26 - ISO14443A_CMD_REQA  0x52 - ISO14443A_CMD_WUPA
1807         uint8_t sel_all[]    = { ISO14443A_CMD_ANTICOLL_OR_SELECT,0x20 };
1808         uint8_t sel_uid[]    = { ISO14443A_CMD_ANTICOLL_OR_SELECT,0x70,0x00,0x00,0x00,0x00,0x00,0x00,0x00};
1809         uint8_t rats[]       = { ISO14443A_CMD_RATS,0x80,0x00,0x00 }; // FSD=256, FSDI=8, CID=0
1810         uint8_t resp[MAX_FRAME_SIZE] = {0}; // theoretically. A usual RATS will be much smaller
1811         uint8_t resp_par[MAX_PARITY_SIZE] = {0};
1812         byte_t uid_resp[4] = {0};
1813         size_t uid_resp_len = 0;
1814
1815         uint8_t sak = 0x04; // cascade uid
1816         int cascade_level = 0;
1817         int len;
1818
1819         // Broadcast for a card, WUPA (0x52) will force response from all cards in the field
1820     ReaderTransmitBitsPar(wupa, 7, NULL, NULL);
1821
1822         // Receive the ATQA
1823         if(!ReaderReceive(resp, resp_par)) return 0;
1824
1825         if(p_hi14a_card) {
1826                 memcpy(p_hi14a_card->atqa, resp, 2);
1827                 p_hi14a_card->uidlen = 0;
1828                 memset(p_hi14a_card->uid,0,10);
1829         }
1830
1831         if (anticollision) {
1832                 // clear uid
1833                 if (uid_ptr)
1834                         memset(uid_ptr,0,10);
1835         }
1836
1837         // reset the PCB block number
1838         iso14_pcb_blocknum = 0;
1839
1840         // check for proprietary anticollision:
1841         if ((resp[0] & 0x1F) == 0) return 3;
1842
1843         // OK we will select at least at cascade 1, lets see if first byte of UID was 0x88 in
1844         // which case we need to make a cascade 2 request and select - this is a long UID
1845         // While the UID is not complete, the 3nd bit (from the right) is set in the SAK.
1846         for(; sak & 0x04; cascade_level++) {
1847                 // SELECT_* (L1: 0x93, L2: 0x95, L3: 0x97)
1848                 sel_uid[0] = sel_all[0] = 0x93 + cascade_level * 2;
1849
1850                 if (anticollision) {
1851                 // SELECT_ALL
1852                         ReaderTransmit(sel_all, sizeof(sel_all), NULL);
1853                         if (!ReaderReceive(resp, resp_par)) return 0;
1854
1855                         if (Demod.collisionPos) {                       // we had a collision and need to construct the UID bit by bit
1856                                 memset(uid_resp, 0, 4);
1857                                 uint16_t uid_resp_bits = 0;
1858                                 uint16_t collision_answer_offset = 0;
1859                                 // anti-collision-loop:
1860                                 while (Demod.collisionPos) {
1861                                         Dbprintf("Multiple tags detected. Collision after Bit %d", Demod.collisionPos);
1862                                         for (uint16_t i = collision_answer_offset; i < Demod.collisionPos; i++, uid_resp_bits++) {      // add valid UID bits before collision point
1863                                                 uint16_t UIDbit = (resp[i/8] >> (i % 8)) & 0x01;
1864                                                 uid_resp[uid_resp_bits / 8] |= UIDbit << (uid_resp_bits % 8);
1865                                         }
1866                                         uid_resp[uid_resp_bits/8] |= 1 << (uid_resp_bits % 8);                                  // next time select the card(s) with a 1 in the collision position
1867                                         uid_resp_bits++;
1868                                         // construct anticollosion command:
1869                                         sel_uid[1] = ((2 + uid_resp_bits/8) << 4) | (uid_resp_bits & 0x07);     // length of data in bytes and bits
1870                                         for (uint16_t i = 0; i <= uid_resp_bits/8; i++) {
1871                                                 sel_uid[2+i] = uid_resp[i];
1872                                         }
1873                                         collision_answer_offset = uid_resp_bits%8;
1874                                         ReaderTransmitBits(sel_uid, 16 + uid_resp_bits, NULL);
1875                                         if (!ReaderReceiveOffset(resp, collision_answer_offset, resp_par)) return 0;
1876                                 }
1877                                 // finally, add the last bits and BCC of the UID
1878                                 for (uint16_t i = collision_answer_offset; i < (Demod.len-1)*8; i++, uid_resp_bits++) {
1879                                         uint16_t UIDbit = (resp[i/8] >> (i%8)) & 0x01;
1880                                         uid_resp[uid_resp_bits/8] |= UIDbit << (uid_resp_bits % 8);
1881                                 }
1882
1883                         } else {                // no collision, use the response to SELECT_ALL as current uid
1884                                 memcpy(uid_resp, resp, 4);
1885                         }
1886
1887                 } else {
1888                         if (cascade_level < num_cascades - 1) {
1889                                 uid_resp[0] = 0x88;
1890                                 memcpy(uid_resp+1, uid_ptr+cascade_level*3, 3);
1891                         } else {
1892                                 memcpy(uid_resp, uid_ptr+cascade_level*3, 4);
1893                         }
1894                 }
1895                 uid_resp_len = 4;
1896
1897                 // calculate crypto UID. Always use last 4 Bytes.
1898                 if(cuid_ptr)
1899                         *cuid_ptr = bytes_to_num(uid_resp, 4);
1900
1901                 // Construct SELECT UID command
1902                 sel_uid[1] = 0x70;                                                                                                      // transmitting a full UID (1 Byte cmd, 1 Byte NVB, 4 Byte UID, 1 Byte BCC, 2 Bytes CRC)
1903                 memcpy(sel_uid+2, uid_resp, 4);                                                                         // the UID received during anticollision, or the provided UID
1904                 sel_uid[6] = sel_uid[2] ^ sel_uid[3] ^ sel_uid[4] ^ sel_uid[5];         // calculate and add BCC
1905                 AppendCrc14443a(sel_uid, 7);                                                                            // calculate and add CRC
1906                 ReaderTransmit(sel_uid, sizeof(sel_uid), NULL);
1907
1908                 // Receive the SAK
1909                 if (!ReaderReceive(resp, resp_par)) return 0;
1910
1911                 sak = resp[0];
1912
1913                 // Test if more parts of the uid are coming
1914                 if ((sak & 0x04) /* && uid_resp[0] == 0x88 */) {
1915                         // Remove first byte, 0x88 is not an UID byte, it CT, see page 3 of:
1916                         // http://www.nxp.com/documents/application_note/AN10927.pdf
1917                         uid_resp[0] = uid_resp[1];
1918                         uid_resp[1] = uid_resp[2];
1919                         uid_resp[2] = uid_resp[3];
1920                         uid_resp_len = 3;
1921                 }
1922
1923                 if(uid_ptr && anticollision)
1924                         memcpy(uid_ptr + (cascade_level*3), uid_resp, uid_resp_len);
1925
1926                 if(p_hi14a_card) {
1927                         memcpy(p_hi14a_card->uid + (cascade_level*3), uid_resp, uid_resp_len);
1928                         p_hi14a_card->uidlen += uid_resp_len;
1929                 }
1930         }
1931
1932         if(p_hi14a_card) {
1933                 p_hi14a_card->sak = sak;
1934                 p_hi14a_card->ats_len = 0;
1935         }
1936
1937         // non iso14443a compliant tag
1938         if( (sak & 0x20) == 0) return 2;
1939
1940         // Request for answer to select
1941         AppendCrc14443a(rats, 2);
1942         ReaderTransmit(rats, sizeof(rats), NULL);
1943
1944         if (!(len = ReaderReceive(resp, resp_par))) return 0;
1945
1946         if(p_hi14a_card) {
1947                 memcpy(p_hi14a_card->ats, resp, sizeof(p_hi14a_card->ats));
1948                 p_hi14a_card->ats_len = len;
1949         }
1950
1951         // set default timeout based on ATS
1952         iso14a_set_ATS_timeout(resp);
1953         return 1;
1954 }
1955
1956 void iso14443a_setup(uint8_t fpga_minor_mode) {
1957
1958         FpgaDownloadAndGo(FPGA_BITSTREAM_HF);
1959         // Set up the synchronous serial port
1960         FpgaSetupSsc();
1961         // connect Demodulated Signal to ADC:
1962         SetAdcMuxFor(GPIO_MUXSEL_HIPKD);
1963
1964         LED_D_OFF();
1965         // Signal field is on with the appropriate LED
1966         if (fpga_minor_mode == FPGA_HF_ISO14443A_READER_MOD ||
1967                 fpga_minor_mode == FPGA_HF_ISO14443A_READER_LISTEN)
1968                 LED_D_ON();
1969
1970         FpgaWriteConfWord(FPGA_MAJOR_MODE_HF_ISO14443A | fpga_minor_mode);
1971
1972         SpinDelay(20);
1973
1974         // Start the timer
1975         StartCountSspClk();
1976
1977         // Prepare the demodulation functions
1978         DemodReset();
1979         UartReset();
1980         NextTransferTime = 2 * DELAY_ARM2AIR_AS_READER;
1981         iso14a_set_timeout(10*106); // 20ms default
1982 }
1983
1984 int iso14_apdu(uint8_t *cmd, uint16_t cmd_len, void *data) {
1985         uint8_t parity[MAX_PARITY_SIZE] = {0x00};
1986         uint8_t real_cmd[cmd_len+4];
1987         real_cmd[0] = 0x0a; //I-Block
1988         // put block number into the PCB
1989         real_cmd[0] |= iso14_pcb_blocknum;
1990         real_cmd[1] = 0x00; //CID: 0 //FIXME: allow multiple selected cards
1991         memcpy(real_cmd+2, cmd, cmd_len);
1992         AppendCrc14443a(real_cmd,cmd_len+2);
1993
1994         ReaderTransmit(real_cmd, cmd_len+4, NULL);
1995         size_t len = ReaderReceive(data, parity);
1996          //DATA LINK ERROR
1997         if (!len) return 0;
1998
1999         uint8_t *data_bytes = (uint8_t *) data;
2000
2001         // if we received an I- or R(ACK)-Block with a block number equal to the
2002         // current block number, toggle the current block number
2003         if (len >= 4 // PCB+CID+CRC = 4 bytes
2004                  && ((data_bytes[0] & 0xC0) == 0 // I-Block
2005                      || (data_bytes[0] & 0xD0) == 0x80) // R-Block with ACK bit set to 0
2006                  && (data_bytes[0] & 0x01) == iso14_pcb_blocknum) // equal block numbers
2007         {
2008                 iso14_pcb_blocknum ^= 1;
2009         }
2010         return len;
2011 }
2012
2013
2014 //-----------------------------------------------------------------------------
2015 // Read an ISO 14443a tag. Send out commands and store answers.
2016 //-----------------------------------------------------------------------------
2017 void ReaderIso14443a(UsbCommand *c) {
2018         iso14a_command_t param = c->arg[0];
2019         size_t len = c->arg[1] & 0xffff;
2020         size_t lenbits = c->arg[1] >> 16;
2021         uint32_t timeout = c->arg[2];
2022         uint8_t *cmd = c->d.asBytes;
2023         uint32_t arg0 = 0;
2024         byte_t buf[USB_CMD_DATA_SIZE] = {0x00};
2025         uint8_t par[MAX_PARITY_SIZE] = {0x00};
2026
2027         if (param & ISO14A_CONNECT)
2028                 clear_trace();
2029
2030         set_tracing(TRUE);
2031
2032         if (param & ISO14A_REQUEST_TRIGGER)
2033                 iso14a_set_trigger(TRUE);
2034
2035         if (param & ISO14A_CONNECT) {
2036                 iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN);
2037                 if(!(param & ISO14A_NO_SELECT)) {
2038                         iso14a_card_select_t *card = (iso14a_card_select_t*)buf;
2039                         arg0 = iso14443a_select_card(NULL,card,NULL, true, 0);
2040                         cmd_send(CMD_ACK, arg0, card->uidlen, 0, buf, sizeof(iso14a_card_select_t));
2041                         // if it fails,  the cmdhf14a.c client quites.. however this one still executes.
2042                         if ( arg0 == 0 ) return;
2043                 }
2044         }
2045
2046         if (param & ISO14A_SET_TIMEOUT)
2047                 iso14a_set_timeout(timeout);
2048
2049         if (param & ISO14A_APDU) {
2050                 arg0 = iso14_apdu(cmd, len, buf);
2051                 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
2052         }
2053
2054         if (param & ISO14A_RAW) {
2055                 if (param & ISO14A_APPEND_CRC) {
2056                         if (param & ISO14A_TOPAZMODE)
2057                                 AppendCrc14443b(cmd,len);
2058                         else
2059                                 AppendCrc14443a(cmd,len);
2060
2061                         len += 2;
2062                         if (lenbits) lenbits += 16;
2063                 }
2064                 if (lenbits>0) {                                // want to send a specific number of bits (e.g. short commands)
2065                         if (param & ISO14A_TOPAZMODE) {
2066                                 int bits_to_send = lenbits;
2067                                 uint16_t i = 0;
2068                                 ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 7), NULL, NULL);             // first byte is always short (7bits) and no parity
2069                                 bits_to_send -= 7;
2070                                 while (bits_to_send > 0) {
2071                                         ReaderTransmitBitsPar(&cmd[i++], MIN(bits_to_send, 8), NULL, NULL);     // following bytes are 8 bit and no parity
2072                                         bits_to_send -= 8;
2073                                 }
2074                         } else {
2075                         GetParity(cmd, lenbits/8, par);
2076                                 ReaderTransmitBitsPar(cmd, lenbits, par, NULL);                                                 // bytes are 8 bit with odd parity
2077                         }
2078                 } else {                                        // want to send complete bytes only
2079                         if (param & ISO14A_TOPAZMODE) {
2080                                 uint16_t i = 0;
2081                                 ReaderTransmitBitsPar(&cmd[i++], 7, NULL, NULL);                                                // first byte: 7 bits, no paritiy
2082                                 while (i < len) {
2083                                         ReaderTransmitBitsPar(&cmd[i++], 8, NULL, NULL);                                        // following bytes: 8 bits, no paritiy
2084                                 }
2085                 } else {
2086                                 ReaderTransmit(cmd,len, NULL);                                                                                  // 8 bits, odd parity
2087                         }
2088                 }
2089                 arg0 = ReaderReceive(buf, par);
2090                 cmd_send(CMD_ACK,arg0,0,0,buf,sizeof(buf));
2091         }
2092
2093         if (param & ISO14A_REQUEST_TRIGGER)
2094                 iso14a_set_trigger(FALSE);
2095
2096         if (param & ISO14A_NO_DISCONNECT)
2097                 return;
2098
2099         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2100         set_tracing(FALSE);
2101         LEDsoff();
2102 }
2103
2104 // Determine the distance between two nonces.
2105 // Assume that the difference is small, but we don't know which is first.
2106 // Therefore try in alternating directions.
2107 int32_t dist_nt(uint32_t nt1, uint32_t nt2) {
2108
2109         if (nt1 == nt2) return 0;
2110
2111         uint32_t nttmp1 = nt1;
2112         uint32_t nttmp2 = nt2;
2113
2114         // 0xFFFF -- Half up and half down to find distance between nonces
2115         for (uint16_t i = 1; i < 32768/8; i += 8) {
2116                 nttmp1 = prng_successor(nttmp1, 1);     if (nttmp1 == nt2) return i;
2117                 nttmp1 = prng_successor(nttmp1, 1);     if (nttmp1 == nt2) return i+1;
2118                 nttmp1 = prng_successor(nttmp1, 1);     if (nttmp1 == nt2) return i+2;
2119                 nttmp1 = prng_successor(nttmp1, 1);     if (nttmp1 == nt2) return i+3;
2120                 nttmp1 = prng_successor(nttmp1, 1);     if (nttmp1 == nt2) return i+4;
2121                 nttmp1 = prng_successor(nttmp1, 1);     if (nttmp1 == nt2) return i+5;
2122                 nttmp1 = prng_successor(nttmp1, 1);     if (nttmp1 == nt2) return i+6;
2123                 nttmp1 = prng_successor(nttmp1, 1);     if (nttmp1 == nt2) return i+7;
2124
2125                 nttmp2 = prng_successor(nttmp2, 1);     if (nttmp2 == nt1) return -i;
2126                 nttmp2 = prng_successor(nttmp2, 1);     if (nttmp2 == nt1) return -(i+1);
2127                 nttmp2 = prng_successor(nttmp2, 1);     if (nttmp2 == nt1) return -(i+2);
2128                 nttmp2 = prng_successor(nttmp2, 1);     if (nttmp2 == nt1) return -(i+3);
2129                 nttmp2 = prng_successor(nttmp2, 1);     if (nttmp2 == nt1) return -(i+4);
2130                 nttmp2 = prng_successor(nttmp2, 1);     if (nttmp2 == nt1) return -(i+5);
2131                 nttmp2 = prng_successor(nttmp2, 1);     if (nttmp2 == nt1) return -(i+6);
2132                 nttmp2 = prng_successor(nttmp2, 1);     if (nttmp2 == nt1) return -(i+7);
2133         }
2134         // either nt1 or nt2 are invalid nonces
2135         return(-99999);
2136 }
2137
2138 //-----------------------------------------------------------------------------
2139 // Recover several bits of the cypher stream. This implements (first stages of)
2140 // the algorithm described in "The Dark Side of Security by Obscurity and
2141 // Cloning MiFare Classic Rail and Building Passes, Anywhere, Anytime"
2142 // (article by Nicolas T. Courtois, 2009)
2143 //-----------------------------------------------------------------------------
2144
2145 void ReaderMifare(bool first_try, uint8_t block, uint8_t keytype ) {
2146
2147         uint8_t mf_auth[]       = { keytype, block, 0x00, 0x00 };
2148         uint8_t mf_nr_ar[]      = { 0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00 };
2149         uint8_t uid[10]         = {0,0,0,0,0,0,0,0,0,0};
2150         uint8_t par_list[8]     = {0,0,0,0,0,0,0,0};
2151         uint8_t ks_list[8]      = {0,0,0,0,0,0,0,0};
2152         uint8_t receivedAnswer[MAX_MIFARE_FRAME_SIZE] = {0x00};
2153         uint8_t receivedAnswerPar[MAX_MIFARE_PARITY_SIZE] = {0x00};
2154         uint8_t par[1] = {0};   // maximum 8 Bytes to be sent here, 1 byte parity is therefore enough
2155         byte_t nt_diff = 0;
2156         uint32_t nt = 0;
2157         uint32_t previous_nt = 0;
2158         uint32_t cuid = 0;
2159
2160         int32_t catch_up_cycles = 0;
2161         int32_t last_catch_up = 0;
2162         int32_t isOK = 0;
2163         int32_t nt_distance = 0;
2164
2165         uint16_t elapsed_prng_sequences = 1;
2166         uint16_t consecutive_resyncs = 0;
2167         uint16_t unexpected_random = 0;
2168         uint16_t sync_tries = 0;
2169
2170         // static variables here, is re-used in the next call
2171         static uint32_t nt_attacked = 0;
2172         static uint32_t sync_time = 0;
2173         static uint32_t sync_cycles = 0;
2174         static uint8_t par_low = 0;
2175         static uint8_t mf_nr_ar3 = 0;
2176
2177         #define PRNG_SEQUENCE_LENGTH    (1 << 16)
2178         #define MAX_UNEXPECTED_RANDOM   4               // maximum number of unexpected (i.e. real) random numbers when trying to sync. Then give up.
2179         #define MAX_SYNC_TRIES          32
2180
2181         AppendCrc14443a(mf_auth, 2);
2182
2183         BigBuf_free(); BigBuf_Clear_ext(false);
2184         clear_trace();
2185         set_tracing(FALSE);
2186         iso14443a_setup(FPGA_HF_ISO14443A_READER_MOD);
2187
2188         sync_time = GetCountSspClk() & 0xfffffff8;
2189         sync_cycles = PRNG_SEQUENCE_LENGTH; // Mifare Classic's random generator repeats every 2^16 cycles (and so do the nonces).
2190         nt_attacked = 0;
2191
2192    if (MF_DBGLEVEL >= 4)        Dbprintf("Mifare::Sync %u", sync_time);
2193
2194         if (first_try) {
2195                 mf_nr_ar3 = 0;
2196                 par_low = 0;
2197         } else {
2198                 // we were unsuccessful on a previous call.
2199                 // Try another READER nonce (first 3 parity bits remain the same)
2200                 ++mf_nr_ar3;
2201                 mf_nr_ar[3] = mf_nr_ar3;
2202                 par[0] = par_low;
2203         }
2204
2205         bool have_uid = FALSE;
2206         uint8_t cascade_levels = 0;
2207
2208         LED_C_ON();
2209         uint16_t i;
2210         for(i = 0; TRUE; ++i) {
2211
2212                 WDT_HIT();
2213
2214                 // Test if the action was cancelled
2215                 if(BUTTON_PRESS()) {
2216                         isOK = -1;
2217                         break;
2218                 }
2219
2220                 // this part is from Piwi's faster nonce collecting part in Hardnested.
2221                 if (!have_uid) { // need a full select cycle to get the uid first
2222                         iso14a_card_select_t card_info;
2223                         if(!iso14443a_select_card(uid, &card_info, &cuid, true, 0)) {
2224                                 if (MF_DBGLEVEL >= 4)   Dbprintf("Mifare: Can't select card (ALL)");
2225                                 break;
2226                         }
2227                         switch (card_info.uidlen) {
2228                                 case 4 : cascade_levels = 1; break;
2229                                 case 7 : cascade_levels = 2; break;
2230                                 case 10: cascade_levels = 3; break;
2231                                 default: break;
2232                         }
2233                         have_uid = TRUE;
2234                 } else { // no need for anticollision. We can directly select the card
2235                         if(!iso14443a_select_card(uid, NULL, &cuid, false, cascade_levels)) {
2236                                 if (MF_DBGLEVEL >= 4)   Dbprintf("Mifare: Can't select card (UID)");
2237                                 continue;
2238                         }
2239                 }
2240
2241                 // Sending timeslot of ISO14443a frame
2242                 sync_time = (sync_time & 0xfffffff8 ) + sync_cycles + catch_up_cycles;
2243                 catch_up_cycles = 0;
2244
2245                 // if we missed the sync time already, advance to the next nonce repeat
2246                 while( GetCountSspClk() > sync_time) {
2247                         ++elapsed_prng_sequences;
2248                         sync_time = (sync_time & 0xfffffff8 ) + sync_cycles;
2249                 }
2250
2251                 // Transmit MIFARE_CLASSIC_AUTH at synctime. Should result in returning the same tag nonce (== nt_attacked)
2252                 ReaderTransmit(mf_auth, sizeof(mf_auth), &sync_time);
2253
2254                 // Receive the (4 Byte) "random" nonce from TAG
2255                 if (!ReaderReceive(receivedAnswer, receivedAnswerPar))
2256                         continue;
2257
2258                 previous_nt = nt;
2259                 nt = bytes_to_num(receivedAnswer, 4);
2260
2261                 // Transmit reader nonce with fake par
2262                 ReaderTransmitPar(mf_nr_ar, sizeof(mf_nr_ar), par, NULL);
2263
2264                 // we didn't calibrate our clock yet,
2265                 // iceman: has to be calibrated every time.
2266                 if (previous_nt && !nt_attacked) {
2267
2268                         nt_distance = dist_nt(previous_nt, nt);
2269
2270                         // if no distance between,  then we are in sync.
2271                         if (nt_distance == 0) {
2272                                 nt_attacked = nt;
2273                         } else {
2274                                 if (nt_distance == -99999) { // invalid nonce received
2275                                         ++unexpected_random;
2276                                         if (unexpected_random > MAX_UNEXPECTED_RANDOM) {
2277                                                 isOK = -3;              // Card has an unpredictable PRNG. Give up
2278                                                 break;
2279                                         } else {
2280                                                 if (sync_cycles <= 0) sync_cycles += PRNG_SEQUENCE_LENGTH;
2281                                                 LED_B_OFF();
2282                                                 continue;               // continue trying...
2283                                         }
2284                                 }
2285
2286                                 if (++sync_tries > MAX_SYNC_TRIES) {
2287                                         isOK = -4;                      // Card's PRNG runs at an unexpected frequency or resets unexpectedly
2288                                         break;
2289                                 }
2290
2291                                 sync_cycles = (sync_cycles - nt_distance)/elapsed_prng_sequences;
2292
2293                                 if (sync_cycles <= 0)
2294                                         sync_cycles += PRNG_SEQUENCE_LENGTH;
2295
2296                                 if (MF_DBGLEVEL >= 4)
2297                                         Dbprintf("calibrating in cycle %d. nt_distance=%d, elapsed_prng_sequences=%d, new sync_cycles: %d\n", i, nt_distance, elapsed_prng_sequences, sync_cycles);
2298
2299                                 LED_B_OFF();
2300                                 continue;
2301                         }
2302                 }
2303                 LED_B_OFF();
2304
2305                 if ( (nt != nt_attacked) && nt_attacked) {      // we somehow lost sync. Try to catch up again...
2306
2307                         catch_up_cycles = ABS(dist_nt(nt_attacked, nt));
2308                         if (catch_up_cycles == 99999) {                 // invalid nonce received. Don't resync on that one.
2309                                 catch_up_cycles = 0;
2310                                 continue;
2311                         }
2312                         // average?
2313                         catch_up_cycles /= elapsed_prng_sequences;
2314
2315                         if (catch_up_cycles == last_catch_up) {
2316                                 ++consecutive_resyncs;
2317                         } else {
2318                                 last_catch_up = catch_up_cycles;
2319                             consecutive_resyncs = 0;
2320                         }
2321
2322                         if (consecutive_resyncs < 3) {
2323                                 if (MF_DBGLEVEL >= 4)
2324                                         Dbprintf("Lost sync in cycle %d. nt_distance=%d. Consecutive Resyncs = %d. Trying one time catch up...\n", i, catch_up_cycles, consecutive_resyncs);
2325                         } else {
2326                                 sync_cycles += catch_up_cycles;
2327
2328                                 if (MF_DBGLEVEL >= 4)
2329                                         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);
2330
2331                                 last_catch_up = 0;
2332                                 catch_up_cycles = 0;
2333                                 consecutive_resyncs = 0;
2334                         }
2335                         continue;
2336                 }
2337
2338                 // Receive answer. This will be a 4 Bit NACK when the 8 parity bits are OK after decoding
2339                 if (ReaderReceive(receivedAnswer, receivedAnswerPar)) {
2340                         catch_up_cycles = 8;    // the PRNG is delayed by 8 cycles due to the NAC (4Bits = 0x05 encrypted) transfer
2341
2342                         if (nt_diff == 0)
2343                                 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
2344
2345                         par_list[nt_diff] = SwapBits(par[0], 8);
2346                         ks_list[nt_diff] = receivedAnswer[0] ^ 0x05;  // xor with NACK value to get keystream
2347
2348                         // Test if the information is complete
2349                         if (nt_diff == 0x07) {
2350                                 isOK = 1;
2351                                 break;
2352                         }
2353
2354                         nt_diff = (nt_diff + 1) & 0x07;
2355                         mf_nr_ar[3] = (mf_nr_ar[3] & 0x1F) | (nt_diff << 5);
2356                         par[0] = par_low;
2357
2358                 } else {
2359                         // No NACK.
2360                         if (nt_diff == 0 && first_try) {
2361                                 par[0]++;
2362                                 if (par[0] == 0x00) {   // tried all 256 possible parities without success. Card doesn't send NACK.
2363                                         isOK = -2;
2364                                         break;
2365                                 }
2366                         } else {
2367                                 // Why this?
2368                                 par[0] = ((par[0] & 0x1F) + 1) | par_low;
2369                         }
2370                 }
2371
2372                 // reset the resyncs since we got a complete transaction on right time.
2373                 consecutive_resyncs = 0;
2374         } // end for loop
2375
2376         mf_nr_ar[3] &= 0x1F;
2377
2378         if (MF_DBGLEVEL >= 4) Dbprintf("Number of sent auth requestes: %u", i);
2379
2380         uint8_t buf[28] = {0x00};
2381         memset(buf, 0x00, sizeof(buf));
2382         num_to_bytes(cuid, 4, buf);
2383         num_to_bytes(nt, 4, buf + 4);
2384         memcpy(buf + 8,  par_list, 8);
2385         memcpy(buf + 16, ks_list, 8);
2386         memcpy(buf + 24, mf_nr_ar, 4);
2387
2388         cmd_send(CMD_ACK, isOK, 0, 0, buf, sizeof(buf) );
2389
2390         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2391         LEDsoff();
2392         set_tracing(FALSE);
2393 }
2394
2395
2396 /**
2397   *MIFARE 1K simulate.
2398   *
2399   *@param flags :
2400   *     FLAG_INTERACTIVE                - In interactive mode, we are expected to finish the operation with an ACK
2401   * FLAG_4B_UID_IN_DATA         - use 4-byte UID in the data-section
2402   * FLAG_7B_UID_IN_DATA         - use 7-byte UID in the data-section
2403   * FLAG_10B_UID_IN_DATA        - use 10-byte UID in the data-section
2404   * FLAG_UID_IN_EMUL            - use 4-byte UID from emulator memory
2405   *     FLAG_NR_AR_ATTACK               - collect NR_AR responses for bruteforcing later
2406   *@param exitAfterNReads, exit simulation after n blocks have been read, 0 is inifite
2407   */
2408 void Mifare1ksim(uint8_t flags, uint8_t exitAfterNReads, uint8_t arg2, uint8_t *datain) {
2409
2410         // init pseudorand
2411         fast_prand( GetTickCount() );
2412
2413         int cardSTATE = MFEMUL_NOFIELD;
2414         int _UID_LEN = 0;  // 4, 7, 10
2415         int vHf = 0;    // in mV
2416         int res = 0;
2417         uint32_t selTimer = 0;
2418         uint32_t authTimer = 0;
2419         uint16_t len = 0;
2420         uint8_t cardWRBL = 0;
2421         uint8_t cardAUTHSC = 0;
2422         uint8_t cardAUTHKEY = 0xff;  // no authentication
2423         uint32_t cuid = 0;
2424         uint32_t ans = 0;
2425         uint32_t cardINTREG = 0;
2426         uint8_t cardINTBLOCK = 0;
2427         struct Crypto1State mpcs = {0, 0};
2428         struct Crypto1State *pcs;
2429         pcs = &mpcs;
2430         uint32_t numReads = 0;  // Counts numer of times reader read a block
2431         uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE] = {0x00};
2432         uint8_t receivedCmd_par[MAX_MIFARE_PARITY_SIZE] = {0x00};
2433         uint8_t response[MAX_MIFARE_FRAME_SIZE] = {0x00};
2434         uint8_t response_par[MAX_MIFARE_PARITY_SIZE] = {0x00};
2435
2436         uint8_t atqa[]   = {0x04, 0x00}; // Mifare classic 1k
2437         uint8_t sak_4[]  = {0x0C, 0x00, 0x00}; // CL1 - 4b uid
2438         uint8_t sak_7[]  = {0x0C, 0x00, 0x00}; // CL2 - 7b uid
2439         uint8_t sak_10[] = {0x0C, 0x00, 0x00}; // CL3 - 10b uid
2440         // uint8_t sak[] = {0x09, 0x3f, 0xcc };  // Mifare Mini
2441
2442         uint8_t rUIDBCC1[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2443         uint8_t rUIDBCC2[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2444         uint8_t rUIDBCC3[] = {0xde, 0xad, 0xbe, 0xaf, 0x62};
2445
2446         // TAG Nonce - Authenticate response
2447         uint8_t rAUTH_NT[4];
2448         uint32_t nonce = prand();
2449         num_to_bytes(nonce, 4, rAUTH_NT);
2450
2451         // uint8_t rAUTH_NT[] = {0x55, 0x41, 0x49, 0x92};// nonce from nested? why this?
2452         uint8_t rAUTH_AT[] = {0x00, 0x00, 0x00, 0x00};
2453
2454         // Here, we collect CUID, NT, NR, AR, CUID2, NT2, NR2, AR2
2455         // This can be used in a reader-only attack.
2456         nonces_t ar_nr_nonces[ATTACK_KEY_COUNT];
2457         memset(ar_nr_nonces, 0x00, sizeof(ar_nr_nonces));
2458
2459         // -- Determine the UID
2460         // Can be set from emulator memory or incoming data
2461         // Length: 4,7,or 10 bytes
2462         if ( (flags & FLAG_UID_IN_EMUL) == FLAG_UID_IN_EMUL)
2463                 emlGetMemBt(datain, 0, 10);  // load 10bytes from EMUL to the datain pointer. to be used below.
2464
2465         if ( (flags & FLAG_4B_UID_IN_DATA) == FLAG_4B_UID_IN_DATA) {
2466                 memcpy(rUIDBCC1, datain, 4);
2467                 _UID_LEN = 4;
2468         } else if ( (flags & FLAG_7B_UID_IN_DATA) == FLAG_7B_UID_IN_DATA) {
2469                 memcpy(&rUIDBCC1[1], datain,   3);
2470                 memcpy( rUIDBCC2,    datain+3, 4);
2471                 _UID_LEN = 7;
2472         } else if ( (flags & FLAG_10B_UID_IN_DATA) == FLAG_10B_UID_IN_DATA) {
2473                 memcpy(&rUIDBCC1[1], datain,   3);
2474                 memcpy(&rUIDBCC2[1], datain+3, 3);
2475                 memcpy( rUIDBCC3,    datain+6, 4);
2476                 _UID_LEN = 10;
2477         }
2478
2479         switch (_UID_LEN) {
2480                 case 4:
2481                         sak_4[0] &= 0xFB;
2482                         // save CUID
2483                         cuid = bytes_to_num(rUIDBCC1, 4);
2484                         // BCC
2485                         rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2486                         if (MF_DBGLEVEL >= 2)   {
2487                                 Dbprintf("4B UID: %02x%02x%02x%02x",
2488                                         rUIDBCC1[0],
2489                                         rUIDBCC1[1],
2490                                         rUIDBCC1[2],
2491                                         rUIDBCC1[3]
2492                                 );
2493                         }
2494                         break;
2495                 case 7:
2496                         atqa[0] |= 0x40;
2497                         sak_7[0] &= 0xFB;
2498                         // save CUID
2499                         cuid = bytes_to_num(rUIDBCC2, 4);
2500                          // CascadeTag, CT
2501                         rUIDBCC1[0] = 0x88;
2502                         // BCC
2503                         rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2504                         rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
2505                         if (MF_DBGLEVEL >= 2)   {
2506                                 Dbprintf("7B UID: %02x %02x %02x %02x %02x %02x %02x",
2507                                         rUIDBCC1[1],
2508                                         rUIDBCC1[2],
2509                                         rUIDBCC1[3],
2510                                         rUIDBCC2[0],
2511                                         rUIDBCC2[1],
2512                                         rUIDBCC2[2],
2513                                         rUIDBCC2[3]
2514                                 );
2515                         }
2516                         break;
2517                 case 10:
2518                         atqa[0] |= 0x80;
2519                         sak_10[0] &= 0xFB;
2520                         // save CUID
2521                         cuid = bytes_to_num(rUIDBCC3, 4);
2522                          // CascadeTag, CT
2523                         rUIDBCC1[0] = 0x88;
2524                         rUIDBCC2[0] = 0x88;
2525                         // BCC
2526                         rUIDBCC1[4] = rUIDBCC1[0] ^ rUIDBCC1[1] ^ rUIDBCC1[2] ^ rUIDBCC1[3];
2527                         rUIDBCC2[4] = rUIDBCC2[0] ^ rUIDBCC2[1] ^ rUIDBCC2[2] ^ rUIDBCC2[3];
2528                         rUIDBCC3[4] = rUIDBCC3[0] ^ rUIDBCC3[1] ^ rUIDBCC3[2] ^ rUIDBCC3[3];
2529
2530                         if (MF_DBGLEVEL >= 2)   {
2531                                 Dbprintf("10B UID: %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
2532                                         rUIDBCC1[1],
2533                                         rUIDBCC1[2],
2534                                         rUIDBCC1[3],
2535                                         rUIDBCC2[1],
2536                                         rUIDBCC2[2],
2537                                         rUIDBCC2[3],
2538                                         rUIDBCC3[0],
2539                                         rUIDBCC3[1],
2540                                         rUIDBCC3[2],
2541                                         rUIDBCC3[3]
2542                                 );
2543                         }
2544                         break;
2545                 default:
2546                         break;
2547         }
2548         // calc some crcs
2549         ComputeCrc14443(CRC_14443_A, sak_4, 1, &sak_4[1], &sak_4[2]);
2550         ComputeCrc14443(CRC_14443_A, sak_7, 1, &sak_7[1], &sak_7[2]);
2551         ComputeCrc14443(CRC_14443_A, sak_10, 1, &sak_10[1], &sak_10[2]);
2552
2553         // We need to listen to the high-frequency, peak-detected path.
2554         iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
2555
2556         // free eventually allocated BigBuf memory but keep Emulator Memory
2557         BigBuf_free_keep_EM();
2558         clear_trace();
2559         set_tracing(TRUE);
2560
2561         bool finished = FALSE;
2562         while (!BUTTON_PRESS() && !finished && !usb_poll_validate_length()) {
2563                 WDT_HIT();
2564
2565                 // find reader field
2566                 if (cardSTATE == MFEMUL_NOFIELD) {
2567                         vHf = (MAX_ADC_HF_VOLTAGE * AvgAdc(ADC_CHAN_HF)) >> 10;
2568                         if (vHf > MF_MINFIELDV) {
2569                                 cardSTATE_TO_IDLE();
2570                                 LED_A_ON();
2571                         }
2572                 }
2573                 if (cardSTATE == MFEMUL_NOFIELD) continue;
2574
2575                 // Now, get data
2576                 res = EmGetCmd(receivedCmd, &len, receivedCmd_par);
2577                 if (res == 2) { //Field is off!
2578                         cardSTATE = MFEMUL_NOFIELD;
2579                         LEDsoff();
2580                         continue;
2581                 } else if (res == 1) {
2582                         break;  // return value 1 means button press
2583                 }
2584
2585                 // REQ or WUP request in ANY state and WUP in HALTED state
2586                 // this if-statement doesn't match the specification above. (iceman)
2587                 if (len == 1 && ((receivedCmd[0] == ISO14443A_CMD_REQA && cardSTATE != MFEMUL_HALTED) || receivedCmd[0] == ISO14443A_CMD_WUPA)) {
2588                         selTimer = GetTickCount();
2589                         EmSendCmd(atqa, sizeof(atqa));
2590                         cardSTATE = MFEMUL_SELECT1;
2591                         crypto1_destroy(pcs);
2592                         cardAUTHKEY = 0xff;
2593                         LEDsoff();
2594                         nonce = prand();
2595                         continue;
2596                 }
2597
2598                 switch (cardSTATE) {
2599                         case MFEMUL_NOFIELD:
2600                         case MFEMUL_HALTED:
2601                         case MFEMUL_IDLE:{
2602                                 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2603                                 break;
2604                         }
2605                         case MFEMUL_SELECT1:{
2606                                 if (len == 2 && (receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT && receivedCmd[1] == 0x20)) {
2607                                         if (MF_DBGLEVEL >= 4)   Dbprintf("SELECT ALL received");
2608                                         EmSendCmd(rUIDBCC1, sizeof(rUIDBCC1));
2609                                         break;
2610                                 }
2611                                 // select card
2612                                 if (len == 9 &&
2613                                                 ( receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT &&
2614                                                   receivedCmd[1] == 0x70 &&
2615                                                   memcmp(&receivedCmd[2], rUIDBCC1, 4) == 0)) {
2616
2617                                         // SAK 4b
2618                                         EmSendCmd(sak_4, sizeof(sak_4));
2619                                         switch(_UID_LEN){
2620                                                 case 4:
2621                                                         cardSTATE = MFEMUL_WORK;
2622                                                         LED_B_ON();
2623                                                         if (MF_DBGLEVEL >= 4)   Dbprintf("--> WORK. anticol1 time: %d", GetTickCount() - selTimer);
2624                                                         continue;
2625                                                 case 7:
2626                                                 case 10:
2627                                                         cardSTATE = MFEMUL_SELECT2;
2628                                                         continue;
2629                                                 default:break;
2630                                         }
2631                                 } else {
2632                                         cardSTATE_TO_IDLE();
2633                                 }
2634                                 break;
2635                         }
2636                         case MFEMUL_SELECT2:{
2637                                 if (!len) {
2638                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2639                                         break;
2640                                 }
2641                                 if (len == 2 && (receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_2 && receivedCmd[1] == 0x20)) {
2642                                         EmSendCmd(rUIDBCC2, sizeof(rUIDBCC2));
2643                                         break;
2644                                 }
2645                                 if (len == 9 &&
2646                                                 (receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_2 &&
2647                                                  receivedCmd[1] == 0x70 &&
2648                                                  memcmp(&receivedCmd[2], rUIDBCC2, 4) == 0) ) {
2649
2650                                         EmSendCmd(sak_7, sizeof(sak_7));
2651                                         switch(_UID_LEN){
2652                                                 case 7:
2653                                                         cardSTATE = MFEMUL_WORK;
2654                                                         LED_B_ON();
2655                                                         if (MF_DBGLEVEL >= 4)   Dbprintf("--> WORK. anticol2 time: %d", GetTickCount() - selTimer);
2656                                                         continue;
2657                                                 case 10:
2658                                                         cardSTATE = MFEMUL_SELECT3;
2659                                                         continue;
2660                                                 default:break;
2661                                         }
2662                                 }
2663                                 cardSTATE_TO_IDLE();
2664                                 break;
2665                         }
2666                         case MFEMUL_SELECT3:{
2667                                 if (!len) {
2668                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2669                                         break;
2670                                 }
2671                                 if (len == 2 && (receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_3 && receivedCmd[1] == 0x20)) {
2672                                         EmSendCmd(rUIDBCC3, sizeof(rUIDBCC3));
2673                                         break;
2674                                 }
2675                                 if (len == 9 &&
2676                                                 (receivedCmd[0] == ISO14443A_CMD_ANTICOLL_OR_SELECT_3 &&
2677                                                  receivedCmd[1] == 0x70 &&
2678                                                  memcmp(&receivedCmd[2], rUIDBCC3, 4) == 0) ) {
2679
2680                                         EmSendCmd(sak_10, sizeof(sak_10));
2681                                         cardSTATE = MFEMUL_WORK;
2682                                         LED_B_ON();
2683                                         if (MF_DBGLEVEL >= 4)   Dbprintf("--> WORK. anticol3 time: %d", GetTickCount() - selTimer);
2684                                         break;
2685                                 }
2686                                 cardSTATE_TO_IDLE();
2687                                 break;
2688                         }
2689                         case MFEMUL_AUTH1:{
2690                                 if( len != 8) {
2691                                         cardSTATE_TO_IDLE();
2692                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2693                                         break;
2694                                 }
2695
2696                                 uint32_t nr = bytes_to_num(receivedCmd, 4);
2697                                 uint32_t ar = bytes_to_num(&receivedCmd[4], 4);
2698
2699                                 // Collect AR/NR per keytype & sector
2700                                 if ( (flags & FLAG_NR_AR_ATTACK) == FLAG_NR_AR_ATTACK ) {
2701
2702                                         int8_t index = -1;
2703                                         int8_t empty = -1;
2704                                         for (uint8_t i = 0; i < ATTACK_KEY_COUNT; i++) {
2705                                                 // find which index to use
2706                                                 if ( (cardAUTHSC == ar_nr_nonces[i].sector) &&  (cardAUTHKEY == ar_nr_nonces[i].keytype))
2707                                                         index = i;
2708
2709                                                 // keep track of empty slots.
2710                                                 if ( ar_nr_nonces[i].state == EMPTY)
2711                                                         empty = i;
2712                                         }
2713                                         // if no empty slots.  Choose first and overwrite.
2714                                         if ( index == -1 ) {
2715                                                 if ( empty == -1 ) {
2716                                                         index = 0;
2717                                                         ar_nr_nonces[index].state = EMPTY;
2718                                                 } else {
2719                                                         index = empty;
2720                                                 }
2721                                         }
2722
2723                                         switch(ar_nr_nonces[index].state) {
2724                                                 case EMPTY: {
2725                                                         // first nonce collect
2726                                                         ar_nr_nonces[index].cuid = cuid;
2727                                                         ar_nr_nonces[index].sector = cardAUTHSC;
2728                                                         ar_nr_nonces[index].keytype = cardAUTHKEY;
2729                                                         ar_nr_nonces[index].nonce = nonce;
2730                                                         ar_nr_nonces[index].nr = nr;
2731                                                         ar_nr_nonces[index].ar = ar;
2732                                                         ar_nr_nonces[index].state = FIRST;
2733                                                         break;
2734                                                 }
2735                                                 case FIRST : {
2736                                                         // second nonce collect
2737                                                         ar_nr_nonces[index].nonce2 = nonce;
2738                                                         ar_nr_nonces[index].nr2 = nr;
2739                                                         ar_nr_nonces[index].ar2 = ar;
2740                                                         ar_nr_nonces[index].state = SECOND;
2741
2742                                                         // send to client
2743                                                         cmd_send(CMD_ACK, CMD_SIMULATE_MIFARE_CARD, 0, 0, &ar_nr_nonces[index], sizeof(nonces_t));
2744
2745                                                         ar_nr_nonces[index].state = EMPTY;
2746                                                         ar_nr_nonces[index].sector = 0;
2747                                                         ar_nr_nonces[index].keytype = 0;
2748                                                         break;
2749                                                 }
2750                                                 default: break;
2751                                         }
2752                                 }
2753
2754                                 crypto1_word(pcs, nr , 1);
2755                                 uint32_t cardRr = ar ^ crypto1_word(pcs, 0, 0);
2756
2757                                 //test if auth OK
2758                                 if (cardRr != prng_successor(nonce, 64)){
2759
2760                                         if (MF_DBGLEVEL >= 3) {
2761                                                 Dbprintf("AUTH FAILED for sector %d with key %c. [nr=%08x  cardRr=%08x] [nt=%08x succ=%08x]"
2762                                                         , cardAUTHSC
2763                                                         , (cardAUTHKEY == 0) ? 'A' : 'B'
2764                                                         , nr
2765                                                         , cardRr
2766                                                         , nonce // nt
2767                                                         , prng_successor(nonce, 64)
2768                                                 );
2769                                         }
2770                                         // Shouldn't we respond anything here?
2771                                         // Right now, we don't nack or anything, which causes the
2772                                         // reader to do a WUPA after a while. /Martin
2773                                         // -- which is the correct response. /piwi
2774                                         cardSTATE_TO_IDLE();
2775                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2776                                         break;
2777                                 }
2778
2779                                 ans = prng_successor(nonce, 96) ^ crypto1_word(pcs, 0, 0);
2780                                 num_to_bytes(ans, 4, rAUTH_AT);
2781                                 EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2782                                 LED_C_ON();
2783
2784                                 if (MF_DBGLEVEL >= 1) {
2785                                         Dbprintf("AUTH COMPLETED for sector %d with key %c. time=%d",
2786                                                 cardAUTHSC,
2787                                                 cardAUTHKEY == 0 ? 'A' : 'B',
2788                                                 GetTickCount() - authTimer
2789                                         );
2790                                 }
2791                                 cardSTATE = MFEMUL_WORK;
2792                                 break;
2793                         }
2794                         case MFEMUL_WORK:{
2795                                 if (len == 0) {
2796                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2797                                         break;
2798                                 }
2799                                 bool encrypted_data = (cardAUTHKEY != 0xFF) ;
2800
2801                                 if(encrypted_data)
2802                                         mf_crypto1_decrypt(pcs, receivedCmd, len);
2803
2804                                 if (len == 4 && (receivedCmd[0] == MIFARE_AUTH_KEYA ||
2805                                                  receivedCmd[0] == MIFARE_AUTH_KEYB)  ) {
2806
2807                                         authTimer = GetTickCount();
2808                                         cardAUTHSC = receivedCmd[1] / 4;  // received block -> sector
2809                                         cardAUTHKEY = receivedCmd[0] & 0x1;
2810                                         crypto1_destroy(pcs);
2811
2812                                         // load key into crypto
2813                                         crypto1_create(pcs, emlGetKey(cardAUTHSC, cardAUTHKEY));
2814
2815                                         if (!encrypted_data) {
2816                                                 // first authentication
2817                                                 // Update crypto state init  (UID ^ NONCE)
2818                                                 crypto1_word(pcs, cuid ^ nonce, 0);
2819                                                 num_to_bytes(nonce, 4, rAUTH_AT);
2820                                         } else {
2821                                                 // nested authentication
2822                                                 ans = nonce ^ crypto1_word(pcs, cuid ^ nonce, 0);
2823                                                 num_to_bytes(ans, 4, rAUTH_AT);
2824
2825                                                 if (MF_DBGLEVEL >= 3) Dbprintf("Reader doing nested authentication for block %d (0x%02x) with key %c", receivedCmd[1], receivedCmd[1],  cardAUTHKEY == 0 ? 'A' : 'B');
2826                                         }
2827
2828                                         EmSendCmd(rAUTH_AT, sizeof(rAUTH_AT));
2829                                         cardSTATE = MFEMUL_AUTH1;
2830                                         break;
2831                                 }
2832
2833                                 // rule 13 of 7.5.3. in ISO 14443-4. chaining shall be continued
2834                                 // BUT... ACK --> NACK
2835                                 if (len == 1 && receivedCmd[0] == CARD_ACK) {
2836                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2837                                         break;
2838                                 }
2839
2840                                 // rule 12 of 7.5.3. in ISO 14443-4. R(NAK) --> R(ACK)
2841                                 if (len == 1 && receivedCmd[0] == CARD_NACK_NA) {
2842                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2843                                         break;
2844                                 }
2845
2846                                 if(len != 4) {
2847                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2848                                         break;
2849                                 }
2850
2851                                 if ( receivedCmd[0] == ISO14443A_CMD_READBLOCK ||
2852                                          receivedCmd[0] == ISO14443A_CMD_WRITEBLOCK ||
2853                                          receivedCmd[0] == MIFARE_CMD_INC ||
2854                                          receivedCmd[0] == MIFARE_CMD_DEC ||
2855                                          receivedCmd[0] == MIFARE_CMD_RESTORE ||
2856                                          receivedCmd[0] == MIFARE_CMD_TRANSFER ) {
2857
2858                                         if (receivedCmd[1] >= 16 * 4) {
2859                                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2860                                                 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]);
2861                                                 break;
2862                                         }
2863
2864                                         if (receivedCmd[1] / 4 != cardAUTHSC) {
2865                                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2866                                                 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);
2867                                                 break;
2868                                         }
2869                                 }
2870                                 // read block
2871                                 if (receivedCmd[0] == ISO14443A_CMD_READBLOCK) {
2872                                         if (MF_DBGLEVEL >= 4) Dbprintf("Reader reading block %d (0x%02x)", receivedCmd[1], receivedCmd[1]);
2873
2874                                         emlGetMem(response, receivedCmd[1], 1);
2875                                         AppendCrc14443a(response, 16);
2876                                         mf_crypto1_encrypt(pcs, response, 18, response_par);
2877                                         EmSendCmdPar(response, 18, response_par);
2878                                         numReads++;
2879                                         if(exitAfterNReads > 0 && numReads >= exitAfterNReads) {
2880                                                 Dbprintf("%d reads done, exiting", numReads);
2881                                                 finished = true;
2882                                         }
2883                                         break;
2884                                 }
2885                                 // write block
2886                                 if (receivedCmd[0] == ISO14443A_CMD_WRITEBLOCK) {
2887                                         if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0xA0 write block %d (%02x)", receivedCmd[1], receivedCmd[1]);
2888                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2889                                         cardSTATE = MFEMUL_WRITEBL2;
2890                                         cardWRBL = receivedCmd[1];
2891                                         break;
2892                                 }
2893                                 // increment, decrement, restore
2894                                 if ( receivedCmd[0] == MIFARE_CMD_INC ||
2895                                      receivedCmd[0] == MIFARE_CMD_DEC ||
2896                                          receivedCmd[0] == MIFARE_CMD_RESTORE) {
2897
2898                                          if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x inc(0xC1)/dec(0xC0)/restore(0xC2) block %d (%02x)",receivedCmd[0], receivedCmd[1], receivedCmd[1]);
2899
2900                                         if (emlCheckValBl(receivedCmd[1])) {
2901                                                 if (MF_DBGLEVEL >= 4) Dbprintf("Reader tried to operate on block, but emlCheckValBl failed, nacking");
2902                                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2903                                                 break;
2904                                         }
2905                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2906                                         if (receivedCmd[0] == MIFARE_CMD_INC)           cardSTATE = MFEMUL_INTREG_INC;
2907                                         if (receivedCmd[0] == MIFARE_CMD_DEC)           cardSTATE = MFEMUL_INTREG_DEC;
2908                                         if (receivedCmd[0] == MIFARE_CMD_RESTORE)       cardSTATE = MFEMUL_INTREG_REST;
2909                                         cardWRBL = receivedCmd[1];
2910                                         break;
2911                                 }
2912                                 // transfer
2913                                 if (receivedCmd[0] == MIFARE_CMD_TRANSFER) {
2914                                         if (MF_DBGLEVEL >= 4) Dbprintf("RECV 0x%02x transfer block %d (%02x)", receivedCmd[0], receivedCmd[1], receivedCmd[1]);
2915                                         if (emlSetValBl(cardINTREG, cardINTBLOCK, receivedCmd[1]))
2916                                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2917                                         else
2918                                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2919                                         break;
2920                                 }
2921                                 // halt
2922                                 if (receivedCmd[0] == ISO14443A_CMD_HALT && receivedCmd[1] == 0x00) {
2923                                         LED_B_OFF();
2924                                         LED_C_OFF();
2925                                         cardSTATE = MFEMUL_HALTED;
2926                                         if (MF_DBGLEVEL >= 4)   Dbprintf("--> HALTED. Selected time: %d ms",  GetTickCount() - selTimer);
2927                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2928                                         break;
2929                                 }
2930                                 // RATS
2931                                 if (receivedCmd[0] == ISO14443A_CMD_RATS) {
2932                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2933                                         break;
2934                                 }
2935                                 // command not allowed
2936                                 if (MF_DBGLEVEL >= 4)   Dbprintf("Received command not allowed, nacking");
2937                                 EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2938                                 break;
2939                         }
2940                         case MFEMUL_WRITEBL2:{
2941                                 if (len == 18) {
2942                                         mf_crypto1_decrypt(pcs, receivedCmd, len);
2943                                         emlSetMem(receivedCmd, cardWRBL, 1);
2944                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_ACK));
2945                                         cardSTATE = MFEMUL_WORK;
2946                                 } else {
2947                                         cardSTATE_TO_IDLE();
2948                                         LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2949                                 }
2950                                 break;
2951                         }
2952                         case MFEMUL_INTREG_INC:{
2953                                 mf_crypto1_decrypt(pcs, receivedCmd, len);
2954                                 memcpy(&ans, receivedCmd, 4);
2955                                 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2956                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2957                                         cardSTATE_TO_IDLE();
2958                                         break;
2959                                 }
2960                                 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2961                                 cardINTREG = cardINTREG + ans;
2962                                 cardSTATE = MFEMUL_WORK;
2963                                 break;
2964                         }
2965                         case MFEMUL_INTREG_DEC:{
2966                                 mf_crypto1_decrypt(pcs, receivedCmd, len);
2967                                 memcpy(&ans, receivedCmd, 4);
2968                                 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2969                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2970                                         cardSTATE_TO_IDLE();
2971                                         break;
2972                                 }
2973                                 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2974                                 cardINTREG = cardINTREG - ans;
2975                                 cardSTATE = MFEMUL_WORK;
2976                                 break;
2977                         }
2978                         case MFEMUL_INTREG_REST:{
2979                                 mf_crypto1_decrypt(pcs, receivedCmd, len);
2980                                 memcpy(&ans, receivedCmd, 4);
2981                                 if (emlGetValBl(&cardINTREG, &cardINTBLOCK, cardWRBL)) {
2982                                         EmSend4bit(mf_crypto1_encrypt4bit(pcs, CARD_NACK_NA));
2983                                         cardSTATE_TO_IDLE();
2984                                         break;
2985                                 }
2986                                 LogTrace(Uart.output, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
2987                                 cardSTATE = MFEMUL_WORK;
2988                                 break;
2989                         }
2990                 }
2991         }
2992
2993         if (MF_DBGLEVEL >= 1)
2994                 Dbprintf("Emulator stopped. Tracing: %d  trace length: %d ", tracing, BigBuf_get_traceLen());
2995
2996         cmd_send(CMD_ACK,1,0,0,0,0);    FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
2997         LEDsoff();
2998         set_tracing(FALSE);
2999 }
3000
3001
3002 //-----------------------------------------------------------------------------
3003 // MIFARE sniffer.
3004 //
3005 // if no activity for 2sec, it sends the collected data to the client.
3006 //-----------------------------------------------------------------------------
3007 // "hf mf sniff"
3008 void RAMFUNC SniffMifare(uint8_t param) {
3009
3010         LEDsoff();
3011
3012         // free eventually allocated BigBuf memory
3013         BigBuf_free(); BigBuf_Clear_ext(false);
3014         clear_trace();
3015         set_tracing(TRUE);
3016
3017         // The command (reader -> tag) that we're receiving.
3018         uint8_t receivedCmd[MAX_MIFARE_FRAME_SIZE] = {0x00};
3019         uint8_t receivedCmdPar[MAX_MIFARE_PARITY_SIZE] = {0x00};
3020
3021         // The response (tag -> reader) that we're receiving.
3022         uint8_t receivedResponse[MAX_MIFARE_FRAME_SIZE] = {0x00};
3023         uint8_t receivedResponsePar[MAX_MIFARE_PARITY_SIZE] = {0x00};
3024
3025         iso14443a_setup(FPGA_HF_ISO14443A_SNIFFER);
3026
3027         // allocate the DMA buffer, used to stream samples from the FPGA
3028         // [iceman] is this sniffed data unsigned?
3029         uint8_t *dmaBuf = BigBuf_malloc(DMA_BUFFER_SIZE);
3030         uint8_t *data = dmaBuf;
3031         uint8_t previous_data = 0;
3032         int maxDataLen = 0;
3033         int dataLen = 0;
3034         bool ReaderIsActive = FALSE;
3035         bool TagIsActive = FALSE;
3036
3037         // Set up the demodulator for tag -> reader responses.
3038         DemodInit(receivedResponse, receivedResponsePar);
3039
3040         // Set up the demodulator for the reader -> tag commands
3041         UartInit(receivedCmd, receivedCmdPar);
3042
3043         // Setup and start DMA.
3044         // set transfer address and number of bytes. Start transfer.
3045         if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, DMA_BUFFER_SIZE) ){
3046                 if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting");
3047                 return;
3048         }
3049
3050         LED_D_OFF();
3051
3052         MfSniffInit();
3053
3054         // And now we loop, receiving samples.
3055         for(uint32_t sniffCounter = 0;; ) {
3056
3057                 LED_A_ON();
3058                 WDT_HIT();
3059
3060                 if(BUTTON_PRESS()) {
3061                         DbpString("cancelled by button");
3062                         break;
3063                 }
3064
3065                 if ((sniffCounter & 0x0000FFFF) == 0) { // from time to time
3066                         // check if a transaction is completed (timeout after 2000ms).
3067                         // if yes, stop the DMA transfer and send what we have so far to the client
3068                         if (MfSniffSend(2000)) {
3069                                 // Reset everything - we missed some sniffed data anyway while the DMA was stopped
3070                                 sniffCounter = 0;
3071                                 data = dmaBuf;
3072                                 maxDataLen = 0;
3073                                 ReaderIsActive = FALSE;
3074                                 TagIsActive = FALSE;
3075                                 // Setup and start DMA. set transfer address and number of bytes. Start transfer.
3076                                 if ( !FpgaSetupSscDma((uint8_t*) dmaBuf, DMA_BUFFER_SIZE) ){
3077                                         if (MF_DBGLEVEL > 1) Dbprintf("FpgaSetupSscDma failed. Exiting");
3078                                         return;
3079                                 }
3080                         }
3081                 }
3082
3083                 int register readBufDataP = data - dmaBuf;      // number of bytes we have processed so far
3084                 int register dmaBufDataP = DMA_BUFFER_SIZE - AT91C_BASE_PDC_SSC->PDC_RCR; // number of bytes already transferred
3085
3086                 if (readBufDataP <= dmaBufDataP)                        // we are processing the same block of data which is currently being transferred
3087                         dataLen = dmaBufDataP - readBufDataP;   // number of bytes still to be processed
3088                 else
3089                         dataLen = DMA_BUFFER_SIZE - readBufDataP + dmaBufDataP; // number of bytes still to be processed
3090
3091                 // test for length of buffer
3092                 if(dataLen > maxDataLen) {                                      // we are more behind than ever...
3093                         maxDataLen = dataLen;
3094                         if(dataLen > (9 * DMA_BUFFER_SIZE / 10)) {
3095                                 Dbprintf("blew circular buffer! dataLen=0x%x", dataLen);
3096                                 break;
3097                         }
3098                 }
3099                 if(dataLen < 1) continue;
3100
3101                 // primary buffer was stopped ( <-- we lost data!
3102                 if (!AT91C_BASE_PDC_SSC->PDC_RCR) {
3103                         AT91C_BASE_PDC_SSC->PDC_RPR = (uint32_t) dmaBuf;
3104                         AT91C_BASE_PDC_SSC->PDC_RCR = DMA_BUFFER_SIZE;
3105                         Dbprintf("RxEmpty ERROR, data length:%d", dataLen); // temporary
3106                 }
3107                 // secondary buffer sets as primary, secondary buffer was stopped
3108                 if (!AT91C_BASE_PDC_SSC->PDC_RNCR) {
3109                         AT91C_BASE_PDC_SSC->PDC_RNPR = (uint32_t) dmaBuf;
3110                         AT91C_BASE_PDC_SSC->PDC_RNCR = DMA_BUFFER_SIZE;
3111                 }
3112
3113                 LED_A_OFF();
3114
3115                 if (sniffCounter & 0x01) {
3116
3117                         // no need to try decoding tag data if the reader is sending
3118                         if(!TagIsActive) {
3119                                 uint8_t readerdata = (previous_data & 0xF0) | (*data >> 4);
3120                                 if(MillerDecoding(readerdata, (sniffCounter-1)*4)) {
3121                                         LED_C_INV();
3122
3123                                         if (MfSniffLogic(receivedCmd, Uart.len, Uart.parity, Uart.bitCount, TRUE)) break;
3124
3125                                         UartInit(receivedCmd, receivedCmdPar);
3126                                         DemodReset();
3127                                 }
3128                                 ReaderIsActive = (Uart.state != STATE_UNSYNCD);
3129                         }
3130
3131                         // no need to try decoding tag data if the reader is sending
3132                         if(!ReaderIsActive) {
3133                                 uint8_t tagdata = (previous_data << 4) | (*data & 0x0F);
3134                                 if(ManchesterDecoding(tagdata, 0, (sniffCounter-1)*4)) {
3135                                         LED_C_INV();
3136
3137                                         if (MfSniffLogic(receivedResponse, Demod.len, Demod.parity, Demod.bitCount, FALSE)) break;
3138
3139                                         DemodReset();
3140                                         UartInit(receivedCmd, receivedCmdPar);
3141                                 }
3142                                 TagIsActive = (Demod.state != DEMOD_UNSYNCD);
3143                         }
3144                 }
3145
3146                 previous_data = *data;
3147                 sniffCounter++;
3148                 data++;
3149
3150                 if(data == dmaBuf + DMA_BUFFER_SIZE)
3151                         data = dmaBuf;
3152
3153         } // main cycle
3154
3155         if (MF_DBGLEVEL >= 1) Dbprintf("maxDataLen=%x, Uart.state=%x, Uart.len=%x", maxDataLen, Uart.state, Uart.len);
3156
3157         FpgaDisableSscDma();
3158         MfSniffEnd();
3159         FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
3160         LEDsoff();
3161         set_tracing(FALSE);
3162 }