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

   1 //Peter Fillmore - 2014
   2 //
   3 //--------------------------------------------------------------------------------
   4 // This code is licensed to you under the terms of the GNU GPL, version 2 or,
   5 // at your option, any later version. See the LICENSE.txt file for the text of
   6 // the license.
   7 //--------------------------------------------------------------------------------
   8 //--------------------------------------------------------------------------------
   9 //Routines to support EMV transactions
  10 //--------------------------------------------------------------------------------
  11 #include "emvcmd.h"
  12
  13 static emvtags currentcard; //use to hold emv tags for the reader/card during communications
  14
  15 // The FPGA will report its internal sending delay in
  16 //uint16_t FpgaSendQueueDelay;
  17
  18
  19 //load individual tag into current card
  20 void EMVloadvalue(uint32_t tag, uint8_t *datain){
  21     //Dbprintf("TAG=%i\n", tag);
  22     //Dbprintf("DATA=%s\n", datain);
  23     emv_settag(tag, datain, &currentcard);
  24 }
  25
  26 void EMVReadRecord(uint8_t arg0, uint8_t arg1,emvtags *currentcard)
  27 {
  28     uint8_t record = arg0;
  29     uint8_t sfi = arg1 & 0x0F; // convert arg1 to number
  30     uint8_t receivedAnswer[MAX_FRAME_SIZE];
  31
  32     // variables
  33     tlvtag inputtag; // create the tag structure
  34     // perform read
  35     // write the result to the provided card
  36     if(!emv_readrecord(record,sfi,receivedAnswer)) {
  37         if(EMV_DBGLEVEL >= 1) Dbprintf("readrecord failed");
  38     }
  39     if(*(receivedAnswer+1) == 0x70){
  40         decode_ber_tlv_item(receivedAnswer+1, &inputtag);
  41         emv_decode_field(inputtag.value, inputtag.valuelength, currentcard);
  42     }
  43     else
  44     {
  45         if(EMV_DBGLEVEL >= 1)
  46             Dbprintf("Record not found SFI=%i RECORD=%i", sfi, record);
  47     }
  48     return;
  49 }
  50
  51 void EMVSelectAID(uint8_t *AID, uint8_t AIDlen, emvtags* inputcard)
  52 {
  53     uint8_t receivedAnswer[MAX_FRAME_SIZE];
  54
  55     // variables
  56     tlvtag inputtag; // create the tag structure
  57     // perform select
  58     if(!emv_select(AID, AIDlen, receivedAnswer)){
  59         if(EMV_DBGLEVEL >= 1) Dbprintf("AID Select failed");
  60         return;
  61     }
  62     // write the result to the provided card
  63     if(*(receivedAnswer+1) == 0x6F){
  64         // decode the 6F template
  65         decode_ber_tlv_item(receivedAnswer+1, &inputtag);
  66         // store 84 and A5 tags
  67         emv_decode_field(inputtag.value, inputtag.valuelength, &currentcard);
  68         // decode the A5 tag
  69         if(currentcard.tag_A5_len > 0)
  70             emv_decode_field(currentcard.tag_A5, currentcard.tag_A5_len, &currentcard);
  71
  72         // copy this result to the DFName
  73         if(currentcard.tag_84_len == 0)
  74             memcpy(currentcard.tag_DFName, currentcard.tag_84, currentcard.tag_84_len);
  75
  76         // decode the BF0C result, assuming 1 directory entry for now
  77         if(currentcard.tag_BF0C_len !=0){
  78             emv_decode_field(currentcard.tag_BF0C, currentcard.tag_BF0C_len, &currentcard);}
  79          // retrieve the AID, use the AID to decide what transaction flow to use
  80         if(currentcard.tag_61_len !=0){
  81                 emv_decode_field(currentcard.tag_61, currentcard.tag_61_len, &currentcard);}
  82     }
  83     if(EMV_DBGLEVEL >= 2)
  84         DbpString("SELECT AID COMPLETED");
  85 }
  86
  87 int EMVGetProcessingOptions(uint8_t *PDOL, uint8_t PDOLlen, emvtags* inputcard)
  88 {
  89     uint8_t receivedAnswer[MAX_FRAME_SIZE];
  90
  91     // variables
  92     tlvtag inputtag; //create the tag structure
  93     // perform pdol
  94     if(!emv_getprocessingoptions(PDOL, PDOLlen, receivedAnswer)){
  95         if(EMV_DBGLEVEL >= 1) Dbprintf("get processing options failed");
  96         return 0;
  97     }
  98     // write the result to the provided card
  99     // FORMAT 1 received
 100     if(receivedAnswer[1] == 0x80){
 101         // store AIP
 102         // decode tag 80
 103         decode_ber_tlv_item(receivedAnswer+1, &inputtag);
 104         memcpy(currentcard.tag_82, &inputtag.value, sizeof(currentcard.tag_82));
 105         memcpy(currentcard.tag_94, &inputtag.value[2], inputtag.valuelength - sizeof(currentcard.tag_82));
 106         currentcard.tag_94_len = inputtag.valuelength - sizeof(currentcard.tag_82);
 107     }
 108     else if(receivedAnswer[1] == 0x77){
 109         // decode the 77 template
 110         decode_ber_tlv_item(receivedAnswer+1, &inputtag);
 111         // store 82 and 94 tags (AIP, AFL)
 112         emv_decode_field(inputtag.value, inputtag.valuelength, &currentcard);
 113     }
 114     if(EMV_DBGLEVEL >= 2)
 115         DbpString("GET PROCESSING OPTIONS COMPLETE");
 116     return 1;
 117 }
 118
 119 int EMVGetChallenge(emvtags* inputcard)
 120 {
 121     uint8_t receivedAnswer[MAX_FRAME_SIZE];
 122     // variables
 123     // tlvtag inputtag; //create the tag structure
 124     // perform select
 125     if(!emv_getchallenge(receivedAnswer)){
 126         if(EMV_DBGLEVEL >= 1) Dbprintf("get processing options failed");
 127         return 1;
 128     }
 129     return 0;
 130 }
 131
 132 int EMVGenerateAC(uint8_t refcontrol, emvtags* inputcard)
 133 {
 134     uint8_t receivedAnswer[MAX_FRAME_SIZE];
 135     uint8_t cdolcommand[MAX_FRAME_SIZE];
 136     uint8_t cdolcommandlen = 0;
 137     tlvtag temptag;
 138
 139     if(currentcard.tag_8C_len > 0) {
 140         emv_generateDOL(currentcard.tag_8C, currentcard.tag_8C_len, &currentcard, cdolcommand, &cdolcommandlen); }
 141     else{
 142             // cdolcommand = NULL; //cdol val is null
 143         cdolcommandlen = 0;
 144     }
 145     // variables
 146     // tlvtag inputtag; //create the tag structure
 147     // perform select
 148     if(!emv_generateAC(refcontrol, cdolcommand, cdolcommandlen,receivedAnswer)){
 149         if(EMV_DBGLEVEL >= 1) Dbprintf("get processing options failed");
 150         return 1;
 151     }
 152     if(receivedAnswer[2] == 0x77) //format 2 data field returned
 153     {
 154         decode_ber_tlv_item(&receivedAnswer[2], &temptag);
 155         emv_decode_field(temptag.value, temptag.valuelength, &currentcard);
 156     }
 157
 158     return 0;
 159 }
 160
 161 //function to perform paywave transaction
 162 //takes in TTQ, amount authorised, unpredicable number and transaction currency code
 163 int EMV_PaywaveTransaction()
 164 {
 165     uint8_t cardMode = 0;
 166     // determine mode of transaction from TTQ
 167     if((currentcard.tag_9F66[0] & 0x40) == 0x40) {
 168         cardMode = VISA_EMV;
 169     }
 170     else if((currentcard.tag_9F66[0] & 0x20) == 0x20) {
 171         cardMode = VISA_FDDA;
 172     }
 173     else if((currentcard.tag_9F66[0] & 0x80) == 0x80) {
 174         if((currentcard.tag_9F66[1] & 0x80) == 1) { //CVN17
 175             cardMode = VISA_CVN17;
 176         } else {
 177             cardMode = VISA_DCVV;
 178         }
 179     }
 180
 181     EMVSelectAID(currentcard.tag_4F,currentcard.tag_4F_len, &currentcard); // perform second AID command
 182
 183     // get PDOL
 184     uint8_t pdolcommand[20]; //20 byte buffer for pdol data
 185     uint8_t pdolcommandlen = 0;
 186     if(currentcard.tag_9F38_len > 0) {
 187         emv_generateDOL(currentcard.tag_9F38, currentcard.tag_9F38_len, &currentcard, pdolcommand, &pdolcommandlen);
 188     }
 189     Dbhexdump(pdolcommandlen, pdolcommand,false);
 190
 191     if(!EMVGetProcessingOptions(pdolcommand,pdolcommandlen, &currentcard)) {
 192         if(EMV_DBGLEVEL >= 1) Dbprintf("PDOL failed");
 193         return 1;
 194     }
 195
 196     Dbprintf("AFL=");
 197     Dbhexdump(currentcard.tag_94_len, currentcard.tag_94,false);
 198     Dbprintf("AIP=");
 199     Dbhexdump(2, currentcard.tag_82, false);
 200     emv_decodeAIP(currentcard.tag_82);
 201 //
 202 //    decode the AFL list and read records
 203     uint8_t i = 0;
 204     uint8_t sfi = 0;
 205     uint8_t recordstart = 0;
 206     uint8_t recordend = 0;
 207     if(currentcard.tag_94_len > 0){
 208         while( i < currentcard.tag_94_len){
 209             sfi = (currentcard.tag_94[i++] & 0xF8) >> 3;
 210             recordstart = currentcard.tag_94[i++];
 211             recordend = currentcard.tag_94[i++];
 212             for(int j=recordstart; j<(recordend+1); j++){
 213             // read records
 214                 EMVReadRecord(j,sfi, &currentcard);
 215                 // while(responsebuffer[0] == 0xF2) {
 216                 //    EMVReadRecord(j,sfi, &currentcard);
 217                 // }
 218             }
 219             i++;
 220         }
 221     }
 222     else {
 223         EMVReadRecord(1,1,&currentcard);
 224         EMVReadRecord(1,2,&currentcard);
 225         EMVReadRecord(1,3,&currentcard);
 226         EMVReadRecord(2,1,&currentcard);
 227         EMVReadRecord(2,2,&currentcard);
 228         EMVReadRecord(2,3,&currentcard);
 229         EMVReadRecord(3,1,&currentcard);
 230         EMVReadRecord(3,3,&currentcard);
 231         EMVReadRecord(4,2,&currentcard);
 232     }
 233     // EMVGetChallenge(&currentcard);
 234     // memcpy(currentcard.tag_9F4C,&responsebuffer[1],8); // ICC UN
 235     EMVGenerateAC(0x81,&currentcard);
 236
 237     Dbprintf("CARDMODE=%i",cardMode);
 238     return 0;
 239 }
 240
 241 int EMV_PaypassTransaction()
 242 {
 243     // uint8_t *responsebuffer  = emv_get_bigbufptr();
 244     // tlvtag temptag; //buffer for decoded tags
 245     // get the current block counter
 246     // select the AID (Mastercard
 247     EMVSelectAID(currentcard.tag_4F,currentcard.tag_4F_len, &currentcard);
 248
 249     // get PDOL
 250     uint8_t pdolcommand[20]; // 20 byte buffer for pdol data
 251     uint8_t pdolcommandlen = 0;
 252     if(currentcard.tag_9F38_len > 0) {
 253         emv_generateDOL(currentcard.tag_9F38, currentcard.tag_9F38_len, &currentcard, pdolcommand, &pdolcommandlen);
 254     }
 255     if(EMVGetProcessingOptions(pdolcommand,pdolcommandlen, &currentcard)) {
 256         if(EMV_DBGLEVEL >= 1) Dbprintf("PDOL failed");
 257         return 1;
 258     }
 259
 260     Dbprintf("AFL=");
 261     Dbhexdump(currentcard.tag_94_len, currentcard.tag_94,false);
 262     Dbprintf("AIP=");
 263     Dbhexdump(2, currentcard.tag_82, false);
 264     emv_decodeAIP(currentcard.tag_82);
 265
 266     // decode the AFL list and read records
 267     uint8_t i = 0;
 268     uint8_t sfi = 0;
 269     uint8_t recordstart = 0;
 270     uint8_t recordend = 0;
 271
 272     while( i< currentcard.tag_94_len){
 273         sfi = (currentcard.tag_94[i++] & 0xF8) >> 3;
 274         recordstart = currentcard.tag_94[i++];
 275         recordend = currentcard.tag_94[i++];
 276         for(int j=recordstart; j<(recordend+1); j++){
 277         // read records
 278             EMVReadRecord(j,sfi, &currentcard);
 279             // while(responsebuffer[0] == 0xF2) {
 280             //    EMVReadRecord(j,sfi, &currentcard);
 281             // }
 282         }
 283         i++;
 284     }
 285     /* get ICC dynamic data */
 286     if((currentcard.tag_82[0] & AIP_CDA_SUPPORTED) == AIP_CDA_SUPPORTED)
 287     {
 288         // DDA supported, so perform GENERATE AC
 289         // generate the iCC UN
 290         EMVGetChallenge(&currentcard);
 291         //memcpy(currentcard.tag_9F4C,&responsebuffer[1],8); // ICC UN
 292         EMVGenerateAC(0x80,&currentcard);
 293
 294
 295         // generate AC2
 296         // if(currentcard.tag_8D_len > 0) {
 297         //    emv_generateDOL(currentcard.tag_8D, currentcard.tag_8D_len, &currentcard, cdolcommand, &cdolcommandlen); }
 298         // else{
 299         //    //cdolcommand = NULL; //cdol val is null
 300         //    cdolcommandlen = 0;
 301         // }
 302         // emv_generateAC(0x80, cdolcommand,cdolcommandlen, &currentcard);
 303
 304         // if(responsebuffer[1] == 0x77) //format 2 data field returned
 305         // {
 306         //    decode_ber_tlv_item(&responsebuffer[1], &temptag);
 307         //    emv_decode_field(temptag.value, temptag.valuelength, &currentcard);
 308         // }
 309     }
 310     // generate cryptographic checksum
 311     // uint8_t udol[4] = {0x00,0x00,0x00,0x00};
 312     // emv_computecryptogram(udol, sizeof(udol));
 313     // if(responsebuffer[1] == 0x77) //format 2 data field returned
 314     // {
 315     //    decode_ber_tlv_item(&responsebuffer[1], &temptag);
 316     //    emv_decode_field(temptag.value, temptag.valuelength, &currentcard);
 317     // }
 318     return 0;
 319 }
 320
 321 void EMVTransaction()
 322 {
 323     //params
 324     uint8_t uid[10] = {0x00};
 325     uint32_t cuid = 0;
 326
 327     //setup stuff
 328         BigBuf_free(); BigBuf_Clear_ext(false);
 329     clear_trace();
 330     set_tracing(TRUE);
 331
 332     LED_A_ON();
 333     LED_B_OFF();
 334     LED_C_OFF();
 335
 336     iso14443a_setup(FPGA_HF_ISO14443A_READER_LISTEN);
 337
 338     while(true) {
 339         if(!iso14443a_select_card(uid, NULL, &cuid, true, 0)) {
 340             if(EMV_DBGLEVEL >= 1) Dbprintf("Can't select card");
 341             break;
 342         }
 343         //selectPPSE
 344         EMVSelectAID((uint8_t *)DF_PSE, 14, &currentcard); //hard coded len
 345
 346         //get response
 347         if (!memcmp(currentcard.tag_4F, AID_MASTERCARD, sizeof(AID_MASTERCARD))){
 348             Dbprintf("Mastercard Paypass Card Detected");
 349             EMV_PaypassTransaction();
 350         }
 351         else if (!memcmp(currentcard.tag_4F, AID_VISA, sizeof(AID_VISA))){
 352             Dbprintf("VISA Paywave Card Detected");
 353             EMV_PaywaveTransaction();
 354         }
 355         //TODO: add other card schemes like AMEX, JCB, China Unionpay etc
 356         break;
 357     }
 358     if (EMV_DBGLEVEL >= 2) DbpString("EMV TRANSACTION FINISHED");
 359         //finish up
 360     FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
 361     LEDsoff();
 362 }
 363
 364 void EMVdumpcard(void){
 365     dumpCard(&currentcard);
 366 }
 367
 368 //SIMULATOR CODE
 369 //-----------------------------------------------------------------------------
 370 // Main loop of simulated tag: receive commands from reader, decide what
 371 // response to send, and send it.
 372 //-----------------------------------------------------------------------------
 373 void SimulateEMVcard()
 374 {
 375         /*
 376
 377         //uint8_t sak; //select ACKnowledge
 378     uint16_t readerPacketLen = 64; //reader packet length - provided by RATS, default to 64 bytes if RATS not supported
 379
 380     // The first response contains the ATQA (note: bytes are transmitted in reverse order).
 381         //uint8_t atqapacket[2];
 382
 383         // The second response contains the (mandatory) first 24 bits of the UID
 384         uint8_t uid0packet[5] = {0x00};
 385     memcpy(uid0packet, currentcard.UID, sizeof(uid0packet));
 386         // Check if the uid uses the (optional) part
 387     uint8_t uid1packet[5] = {0x00};
 388     memcpy(uid1packet, currentcard.UID, sizeof(uid1packet));
 389
 390         // Calculate the BitCountCheck (BCC) for the first 4 bytes of the UID.
 391         uid0packet[4] = uid0packet[0] ^ uid0packet[1] ^ uid0packet[2] ^ uid0packet[3];
 392
 393         // Prepare the mandatory SAK (for 4 and 7 byte UID)
 394         uint8_t sak0packet[3] = {0x00};
 395     memcpy(sak0packet,&currentcard.SAK1,1);
 396         ComputeCrc14443(CRC_14443_A, sak0packet, 1, &sak0packet[1], &sak0packet[2]);
 397         uint8_t sak1packet[3]  = {0x00};
 398     memcpy(sak1packet,&currentcard.SAK2,1);
 399         // Prepare the optional second SAK (for 7 byte UID), drop the cascade bit
 400         ComputeCrc14443(CRC_14443_A, sak1packet, 1, &sak1packet[1], &sak1packet[2]);
 401
 402     uint8_t authanspacket[] = { 0x00, 0x00, 0x00, 0x00 }; // Very random tag nonce
 403     //setup response to ATS
 404     uint8_t ratspacket[currentcard.ATS_len];
 405     memcpy(ratspacket,currentcard.ATS, currentcard.ATS_len);
 406     AppendCrc14443a(ratspacket,sizeof(ratspacket)-2);
 407
 408         // Format byte = 0x58: FSCI=0x08 (FSC=256), TA(1) and TC(1) present,
 409         // TA(1) = 0x80: different divisors not supported, DR = 1, DS = 1
 410         // 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)
 411         // TC(1) = 0x02: CID supported, NAD not supported
 412         //ComputeCrc14443(CRC_14443_A, response6, 4, &response6[4], &response6[5]);
 413
 414     //Receive Acknowledge responses differ by PCB byte
 415     uint8_t rack0packet[] = {0xa2,0x00,0x00};
 416     AppendCrc14443a(rack0packet,1);
 417     uint8_t rack1packet[] = {0xa3,0x00,0x00};
 418     AppendCrc14443a(rack1packet,1);
 419     //Negative Acknowledge
 420     uint8_t rnak0packet[] = {0xb2,0x00,0x00};
 421     uint8_t rnak1packet[] = {0xb3,0x00,0x00};
 422     AppendCrc14443a(rnak0packet,1);
 423     AppendCrc14443a(rnak1packet,1);
 424
 425     //Protocol and parameter selection response, just say yes
 426     uint8_t ppspacket[] = {0xd0,0x00,0x00};
 427     AppendCrc14443a(ppspacket,1);
 428
 429     //hardcoded WTX packet - set to max time (49)
 430     uint8_t wtxpacket[] ={0xf2,0x31,0x00,0x00};
 431     AppendCrc14443a(wtxpacket,2);
 432
 433     //added additional responses for different readers, namely protocol parameter select and Receive acknowledments. - peter fillmore.
 434     //added defininitions for predone responses to aid readability
 435     #define ATR     0
 436     #define UID1    1
 437     #define UID2    2
 438     #define SELACK1 3
 439     #define SELACK2 4
 440     #define AUTH_ANS 5
 441     #define ATS     6
 442     #define RACK0   7
 443     #define RACK1   8
 444     #define RNAK0   9
 445     #define RNAK1   10
 446     #define PPSresponse 11
 447     #define WTX    12
 448
 449     #define TAG_RESPONSE_COUNT 13
 450         tag_response_info_t responses[TAG_RESPONSE_COUNT] = {
 451                 { .response = currentcard.ATQA,  .response_n = sizeof(currentcard.ATQA)  },  // Answer to request - respond with card type
 452                 { .response = uid0packet,  .response_n = sizeof(uid0packet)  },  // Anticollision cascade1 - respond with uid
 453                 { .response = uid1packet, .response_n = sizeof(uid1packet) },  // Anticollision cascade2 - respond with 2nd half of uid if asked
 454                 { .response = sak0packet,  .response_n = sizeof(sak0packet)  },  // Acknowledge select - cascade 1
 455                 { .response = sak1packet, .response_n = sizeof(sak1packet) },  // Acknowledge select - cascade 2
 456                 { .response = authanspacket,  .response_n = sizeof(authanspacket)  },  // Authentication answer (random nonce)
 457                 { .response = ratspacket,  .response_n = sizeof(ratspacket)  },  // dummy ATS (pseudo-ATR), answer to RATS
 458         { .response = rack0packet, .response_n = sizeof(rack0packet) },  //R(ACK)0
 459         { .response = rack1packet, .response_n = sizeof(rack1packet) },  //R(ACK)0
 460         { .response = rnak0packet, .response_n = sizeof(rnak0packet) },  //R(NAK)0
 461         { .response = rnak1packet, .response_n = sizeof(rnak1packet) },  //R(NAK)1
 462         { .response = ppspacket, .response_n = sizeof(ppspacket)},       //PPS packet
 463         { .response = wtxpacket, .response_n = sizeof(wtxpacket)},       //WTX packet
 464 };
 465
 466     //calculated length of predone responses
 467     uint16_t allocatedtaglen = 0;
 468     for(int i=0;i<TAG_RESPONSE_COUNT;i++){
 469         allocatedtaglen += responses[i].response_n;
 470     }
 471         //uint8_t selectOrder = 0;
 472
 473         BigBuf_free_keep_EM();
 474     // Allocate 512 bytes for the dynamic modulation, created when the reader queries for it
 475         // Such a response is less time critical, so we can prepare them on the fly
 476
 477     #define DYNAMIC_RESPONSE_BUFFER_SIZE 256 //max frame size
 478         #define DYNAMIC_MODULATION_BUFFER_SIZE 2 + 9*DYNAMIC_RESPONSE_BUFFER_SIZE //(start and stop bit, 8 bit packet with 1 bit parity
 479
 480     //uint8_t dynamic_response_buffer[DYNAMIC_RESPONSE_BUFFER_SIZE];
 481         //uint8_t dynamic_modulation_buffer[DYNAMIC_MODULATION_BUFFER_SIZE];
 482     uint8_t *dynamic_response_buffer = BigBuf_malloc(DYNAMIC_RESPONSE_BUFFER_SIZE);
 483     uint8_t *dynamic_modulation_buffer = BigBuf_malloc(DYNAMIC_MODULATION_BUFFER_SIZE);
 484
 485     tag_response_info_t dynamic_response_info = {
 486                 .response = dynamic_response_buffer,
 487                 .response_n = 0,
 488                 .modulation = dynamic_modulation_buffer,
 489                 .modulation_n = 0
 490         };
 491         // allocate buffers from BigBuf (so we're not in the stack)
 492         uint8_t *receivedCmd = BigBuf_malloc(MAX_FRAME_SIZE);
 493         uint8_t *receivedCmdPar = BigBuf_malloc(MAX_PARITY_SIZE);
 494     //uint8_t* free_buffer_pointer;
 495     //free_buffer_pointer = BigBuf_malloc((allocatedtaglen*8) +(allocatedtaglen) + (TAG_RESPONSE_COUNT * 3));
 496     BigBuf_malloc((allocatedtaglen*8) +(allocatedtaglen) + (TAG_RESPONSE_COUNT * 3));
 497     // clear trace
 498         clear_trace();
 499         set_tracing(TRUE);
 500
 501         // Prepare the responses of the anticollision phase
 502         // there will be not enough time to do this at the moment the reader sends it REQA
 503         for (size_t i=0; i<TAG_RESPONSE_COUNT; i++)
 504                 prepare_allocated_tag_modulation(&responses[i]);
 505
 506         int len = 0;
 507
 508         // To control where we are in the protocol
 509         int order = 0;
 510         int lastorder;
 511     int currentblock = 1; //init to 1
 512     int previousblock = 0; //used to store previous block counter
 513
 514         // Just to allow some checks
 515         int happened = 0;
 516         int happened2 = 0;
 517         int cmdsRecvd = 0;
 518
 519         // We need to listen to the high-frequency, peak-detected path.
 520         iso14443a_setup(FPGA_HF_ISO14443A_TAGSIM_LISTEN);
 521
 522         cmdsRecvd = 0;
 523         tag_response_info_t* p_response;
 524
 525         LED_A_ON();
 526         for(;;) {
 527                 // Clean receive command buffer
 528
 529                 if(!GetIso14443aCommandFromReader(receivedCmd, receivedCmdPar, &len)) {
 530                         DbpString("Button press");
 531                         break;
 532                 }
 533
 534                 p_response = NULL;
 535
 536                 // Okay, look at the command now.
 537             previousblock = currentblock; //get previous block
 538         lastorder = order;
 539             currentblock = receivedCmd[0] & 0x01;
 540
 541         if(receivedCmd[0] == 0x26) { // Received a REQUEST
 542                         p_response = &responses[ATR]; order = ISO14443A_CMD_REQA;
 543                 } else if(receivedCmd[0] == 0x52) { // Received a WAKEUP
 544                         p_response = &responses[ATR]; order = ISO14443A_CMD_WUPA;
 545                 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x93) {   // Received request for UID (cascade 1)
 546                         p_response = &responses[UID1]; order =  ISO14443A_CMD_ANTICOLL_OR_SELECT;
 547                 } else if(receivedCmd[1] == 0x20 && receivedCmd[0] == 0x95) {   // Received request for UID (cascade 2)
 548                         p_response = &responses[UID2]; order =  ISO14443A_CMD_ANTICOLL_OR_SELECT_2;
 549                 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x93) {   // Received a SELECT (cascade 1)
 550                         p_response = &responses[SELACK1]; order =  ISO14443A_CMD_ANTICOLL_OR_SELECT;
 551                 } else if(receivedCmd[1] == 0x70 && receivedCmd[0] == 0x95) {   // Received a SELECT (cascade 2)
 552                         p_response = &responses[SELACK2]; order =  ISO14443A_CMD_ANTICOLL_OR_SELECT_2;
 553                 } else if((receivedCmd[0] & 0xA2) == 0xA2){ //R-Block received
 554             if(previousblock == currentblock){ //rule 11, retransmit last block
 555                         p_response = &dynamic_response_info;
 556             } else {
 557                 if((receivedCmd[0] & 0xB2) == 0xB2){ //RNAK, rule 12
 558                     if(currentblock == 0)
 559                         p_response = &responses[RACK0];
 560                     else
 561                         p_response = &responses[RACK1];
 562                                 } else {
 563                     //rule 13
 564                     //TODO: implement chaining
 565                 }
 566             }
 567         }
 568         else if(receivedCmd[0] == 0xD0){ //Protocol and parameter selection response
 569             p_response = &responses[PPSresponse];
 570                         order = PPS;
 571         }
 572         else if(receivedCmd[0] == 0x30) {       // Received a (plain) READ
 573                     //we're an EMV card - so no read commands
 574             p_response = NULL;
 575                 } else if(receivedCmd[0] == 0x50) {     // Received a HALT
 576                         LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
 577                         p_response = NULL;
 578                         order = HLTA;
 579                 } else if(receivedCmd[0] == 0x60 || receivedCmd[0] == 0x61) {   // Received an authentication request
 580                         p_response = &responses[AUTH_ANS];
 581                         order = AUTH;
 582                 } else if(receivedCmd[0] == 0xE0) {     // Received a RATS request
 583                     readerPacketLen = GetReaderLength(receivedCmd); //get length of supported packet
 584                         p_response = &responses[ATS];
 585                         order = RATS;
 586                 } else if (order == AUTH && len == 8) { // Received {nr] and {ar} (part of authentication)
 587                         LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
 588                         uint32_t nr = bytes_to_num(receivedCmd,4);
 589                         uint32_t ar = bytes_to_num(receivedCmd+4,4);
 590                         Dbprintf("Auth attempt {nr}{ar}: %08x %08x",nr,ar);
 591                 } else {
 592                         // Check for ISO 14443A-4 compliant commands, look at left nibble
 593                         switch (receivedCmd[0]) {
 594                                 case 0x0B:
 595                                 case 0x0A: // IBlock (command)
 596                 case 0x02:
 597                 case 0x03: {
 598                                     dynamic_response_info.response_n = 0;
 599                     dynamic_response_info.response[0] = receivedCmd[0]; // copy PCB
 600                     //dynamic_response_info.response[1] = receivedCmd[1]; // copy PCB
 601                     dynamic_response_info.response_n++ ;
 602                     switch(receivedCmd[1]) {
 603                         case 0x00:
 604                             switch(receivedCmd[2]){
 605                                 case 0xA4: //select
 606                                     if(receivedCmd[5] == 0x0E){
 607                                     }
 608                                     else if(receivedCmd[5] == 0x07){
 609                                             //selectOrder = 0;
 610                                     }
 611                                     else{ //send not supported msg
 612                                         memcpy(dynamic_response_info.response+1, "\x6a\x82", 2);
 613                                         dynamic_response_info.response_n += 2;
 614                                     }
 615                                     break;
 616                                 case 0xB2: //read record
 617                                     if(receivedCmd[3] == 0x01 && receivedCmd[4] == 0x0C){
 618                                         dynamic_response_info.response_n += 2;
 619                                         Dbprintf("READ RECORD 1 1");
 620                                     }
 621                                     break;
 622                                 }
 623                                                                 break;
 624                         case 0x80:
 625                             switch(receivedCmd[2]){
 626                                 case 0xA8: //get processing options
 627                                     break;
 628                                             }
 629                         }
 630                     }break;
 631                             case 0x1A:
 632                             case 0x1B: { // Chaining command
 633                                       dynamic_response_info.response[0] = 0xaa | ((receivedCmd[0]) & 1);
 634                                       dynamic_response_info.response_n = 2;
 635                                     } break;
 636
 637                                 case 0xaa:
 638                                 case 0xbb: {
 639                                   dynamic_response_info.response[0] = receivedCmd[0] ^ 0x11;
 640                                   dynamic_response_info.response_n = 2;
 641                                 } break;
 642
 643                                 case 0xBA: { //
 644                                   memcpy(dynamic_response_info.response,"\xAB\x00",2);
 645                                   dynamic_response_info.response_n = 2;
 646                                 } break;
 647
 648                                 case 0xCA:
 649                 case 0xC2: { // Readers sends deselect command
 650                                   //we send the command back - this is what tags do in android implemenation i believe - peterfillmore
 651                    memcpy(dynamic_response_info.response,receivedCmd,1);
 652                                    dynamic_response_info.response_n = 1;
 653                                 } break;
 654
 655                                 default: {
 656                                         // Never seen this command before
 657                                         LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
 658                                         Dbprintf("Received unknown command (len=%d):",len);
 659                                         Dbhexdump(len,receivedCmd,false);
 660                                         // Do not respond
 661                                         dynamic_response_info.response_n = 0;
 662                                 } break;
 663                         }
 664
 665                         if (dynamic_response_info.response_n > 0) {
 666                                 // Copy the CID from the reader query
 667                                 //dynamic_response_info.response[1] = receivedCmd[1];
 668
 669                                 // Add CRC bytes, always used in ISO 14443A-4 compliant cards
 670                                 AppendCrc14443a(dynamic_response_info.response,dynamic_response_info.response_n);
 671                                 dynamic_response_info.response_n += 2;
 672                 if(dynamic_response_info.response_n > readerPacketLen){ //throw error if our reader doesn't support the send packet length
 673                     Dbprintf("Error: tag response is longer then what the reader supports, TODO:implement command chaining");
 674                                         LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
 675                                         break;
 676                 }
 677                                 if (prepare_tag_modulation(&dynamic_response_info,DYNAMIC_MODULATION_BUFFER_SIZE) == false) {
 678                                         Dbprintf("Error preparing tag response");
 679                                         LogTrace(receivedCmd, Uart.len, Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG, Uart.parity, TRUE);
 680                                         break;
 681                                 }
 682                                 p_response = &dynamic_response_info;
 683                         }
 684                 }
 685
 686                 // Count number of wakeups received after a halt
 687                 if(order == HLTA && lastorder == PPS) { happened++; }
 688
 689                 // Count number of other messages after a halt
 690                 if(order != HLTA && lastorder == PPS) { happened2++; }
 691
 692                 if(cmdsRecvd > 999) {
 693                         DbpString("1000 commands later...");
 694                         break;
 695                 }
 696                 cmdsRecvd++;
 697
 698                 if (p_response != NULL) {
 699                         EmSendCmd14443aRaw(p_response->modulation, p_response->modulation_n, receivedCmd[0] == 0x52);
 700                         // do the tracing for the previous reader request and this tag answer:
 701                         uint8_t par[MAX_PARITY_SIZE] = {0x00};
 702                         GetParity(p_response->response, p_response->response_n, par);
 703
 704                         EmLogTrace(Uart.output,
 705                                                 Uart.len,
 706                                                 Uart.startTime*16 - DELAY_AIR2ARM_AS_TAG,
 707                                                 Uart.endTime*16 - DELAY_AIR2ARM_AS_TAG,
 708                                                 Uart.parity,
 709                                                 p_response->response,
 710                                                 p_response->response_n,
 711                                                 LastTimeProxToAirStart*16 + DELAY_ARM2AIR_AS_TAG,
 712                                                 (LastTimeProxToAirStart + p_response->ProxToAirDuration)*16 + DELAY_ARM2AIR_AS_TAG,
 713                                                 par);
 714                 }
 715
 716                 if (!tracing) {
 717                         Dbprintf("Trace Full. Simulation stopped.");
 718                         break;
 719                 }
 720         }
 721
 722         Dbprintf("%x %x %x", happened, happened2, cmdsRecvd);
 723         LED_A_OFF();
 724         BigBuf_free_keep_EM();
 725
 726         */
 727 }