git.zerfleddert.de Git - proxmark3-svn/blob - client/util.c

   1 //-----------------------------------------------------------------------------
   2 // Copyright (C) 2010 iZsh <izsh at fail0verflow.com>
   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 // utilities
   9 //-----------------------------------------------------------------------------
  10
  11 #include "util.h"
  12
  13 #include <stdint.h>
  14 #include <string.h>
  15 #include <ctype.h>
  16 #include <stdlib.h>
  17 #include <stdio.h>
  18 #include <time.h>
  19
  20 #ifdef _WIN32
  21 #include <windows.h>
  22 #endif
  23
  24 #define MAX_BIN_BREAK_LENGTH   (3072+384+1)
  25
  26 #ifndef _WIN32
  27 #include <termios.h>
  28 #include <sys/ioctl.h>
  29 #include <unistd.h>
  30
  31 int ukbhit(void)
  32 {
  33   int cnt = 0;
  34   int error;
  35   static struct termios Otty, Ntty;
  36
  37   if ( tcgetattr(STDIN_FILENO, &Otty) == -1 ) return -1;
  38   Ntty = Otty;
  39
  40   Ntty.c_iflag          = 0x0000;   // input mode
  41   Ntty.c_oflag          = 0x0000;   // output mode
  42   Ntty.c_lflag         &= ~ICANON;  // control mode = raw
  43   Ntty.c_cc[VMIN]       = 1;        // return if at least 1 character is in the queue
  44   Ntty.c_cc[VTIME]      = 0;        // no timeout. Wait forever
  45
  46   if (0 == (error = tcsetattr(STDIN_FILENO, TCSANOW, &Ntty))) {   // set new attributes
  47     error += ioctl(STDIN_FILENO, FIONREAD, &cnt);                 // get number of characters availabe
  48     error += tcsetattr(STDIN_FILENO, TCSANOW, &Otty);             // reset attributes
  49   }
  50
  51   return ( error == 0 ? cnt : -1 );
  52 }
  53
  54 #else
  55
  56 #include <conio.h>
  57 int ukbhit(void) {
  58         return kbhit();
  59 }
  60 #endif
  61
  62 // log files functions
  63 void AddLogLine(char *file, char *extData, char *c) {
  64         FILE *fLog = NULL;
  65     char filename[FILE_PATH_SIZE] = {0x00};
  66     int len = 0;
  67
  68     len = strlen(file);
  69     if (len > FILE_PATH_SIZE) len = FILE_PATH_SIZE;
  70     memcpy(filename, file, len);
  71
  72         fLog = fopen(filename, "a");
  73         if (!fLog) {
  74                 printf("Could not append log file %s", filename);
  75                 return;
  76         }
  77
  78         fprintf(fLog, "%s", extData);
  79         fprintf(fLog, "%s\n", c);
  80         fclose(fLog);
  81 }
  82
  83 void AddLogHex(char *fileName, char *extData, const uint8_t * data, const size_t len){
  84         AddLogLine(fileName, extData, sprint_hex(data, len));
  85 }
  86
  87 void AddLogUint64(char *fileName, char *extData, const uint64_t data) {
  88   char buf[100] = {0};
  89         sprintf(buf, "%x%x", (unsigned int)((data & 0xFFFFFFFF00000000) >> 32), (unsigned int)(data & 0xFFFFFFFF));
  90         AddLogLine(fileName, extData, buf);
  91 }
  92
  93 void AddLogCurrentDT(char *fileName) {
  94         char buff[20];
  95         struct tm *curTime;
  96
  97         time_t now = time(0);
  98         curTime = gmtime(&now);
  99
 100         strftime (buff, sizeof(buff), "%Y-%m-%d %H:%M:%S", curTime);
 101         AddLogLine(fileName, "\nanticollision: ", buff);
 102 }
 103
 104 void FillFileNameByUID(char *fileName, uint8_t * uid, char *ext, int byteCount) {
 105         char * fnameptr = fileName;
 106         memset(fileName, 0x00, 200);
 107
 108         for (int j = 0; j < byteCount; j++, fnameptr += 2)
 109                 sprintf(fnameptr, "%02x", (unsigned int) uid[j]);
 110         sprintf(fnameptr, "%s", ext);
 111 }
 112
 113 void hex_to_buffer(const uint8_t *buf, const uint8_t *hex_data, const size_t hex_len, const size_t hex_max_len,
 114         const size_t min_str_len, const size_t spaces_between, bool uppercase) {
 115
 116         char *tmp = (char *)buf;
 117         size_t i;
 118         memset(tmp, 0x00, hex_max_len);
 119
 120         int maxLen = ( hex_len > hex_max_len) ? hex_max_len : hex_len;
 121
 122         for (i = 0; i < maxLen; ++i, tmp += 2 + spaces_between) {
 123                 sprintf(tmp, (uppercase) ? "%02X" : "%02x", (unsigned int) hex_data[i]);
 124
 125                 for (int j = 0; j < spaces_between; j++)
 126                         sprintf(tmp + 2 + j, " ");
 127         }
 128
 129         i *= (2 + spaces_between);
 130         int minStrLen = min_str_len > i ? min_str_len : 0;
 131         if (minStrLen > hex_max_len)
 132                 minStrLen = hex_max_len;
 133         for(; i < minStrLen; i++, tmp += 1)
 134                 sprintf(tmp, " ");
 135
 136         return;
 137 }
 138
 139 // printing and converting functions
 140
 141 void print_hex(const uint8_t * data, const size_t len)
 142 {
 143         size_t i;
 144
 145         for (i=0; i < len; i++)
 146                 printf("%02x ", data[i]);
 147
 148         printf("\n");
 149 }
 150
 151 void print_hex_break(const uint8_t *data, const size_t len, uint8_t breaks) {
 152
 153         int rownum = 0;
 154         printf("[%02d] | ", rownum);
 155         for (int i = 0; i < len; ++i) {
 156
 157                 printf("%02X ", data[i]);
 158
 159                 // check if a line break is needed
 160                 if ( breaks > 0 && !((i+1) % breaks) && (i+1 < len) ) {
 161                         ++rownum;
 162                         printf("\n[%02d] | ", rownum);
 163                 }
 164         }
 165         printf("\n");
 166 }
 167
 168 char *sprint_hex(const uint8_t *data, const size_t len) {
 169         static char buf[1025] = {0};
 170
 171         hex_to_buffer((uint8_t *)buf, data, len, sizeof(buf) - 1, 0, 1, false);
 172
 173         return buf;
 174 }
 175
 176 char *sprint_hex_inrow_ex(const uint8_t *data, const size_t len, const size_t min_str_len) {
 177         static char buf[1025] = {0};
 178
 179         hex_to_buffer((uint8_t *)buf, data, len, sizeof(buf) - 1, min_str_len, 0, false);
 180
 181         return buf;
 182 }
 183
 184 char *sprint_hex_inrow(const uint8_t *data, const size_t len) {
 185         return sprint_hex_inrow_ex(data, len, 0);
 186 }
 187
 188 char *sprint_bin_break(const uint8_t *data, const size_t len, const uint8_t breaks) {
 189         // make sure we don't go beyond our char array memory
 190         int max_len;
 191         if (breaks==0)
 192                 max_len = ( len > MAX_BIN_BREAK_LENGTH ) ? MAX_BIN_BREAK_LENGTH : len;
 193         else
 194                 max_len = ( len+(len/breaks) > MAX_BIN_BREAK_LENGTH ) ? MAX_BIN_BREAK_LENGTH : len+(len/breaks);
 195
 196         static char buf[MAX_BIN_BREAK_LENGTH]; // 3072 + end of line characters if broken at 8 bits
 197         //clear memory
 198         memset(buf, 0x00, sizeof(buf));
 199         char *tmp = buf;
 200
 201         size_t in_index = 0;
 202         // loop through the out_index to make sure we don't go too far
 203         for (size_t out_index=0; out_index < max_len; out_index++) {
 204                 // set character - (should be binary but verify it isn't more than 1 digit)
 205                 if (data[in_index]<10)
 206                         sprintf(tmp++, "%u", (unsigned int) data[in_index]);
 207                 // check if a line break is needed and we have room to print it in our array
 208                 if ( (breaks > 0) && !((in_index+1) % breaks) && (out_index+1 < max_len) ) {
 209                         // increment and print line break
 210                         out_index++;
 211                         sprintf(tmp++, "%s","\n");
 212                 }
 213                 in_index++;
 214         }
 215
 216         return buf;
 217 }
 218
 219 char *sprint_bin(const uint8_t *data, const size_t len) {
 220         return sprint_bin_break(data, len, 0);
 221 }
 222
 223 char *sprint_hex_ascii(const uint8_t *data, const size_t len) {
 224         static char buf[1024];
 225         char *tmp = buf;
 226         memset(buf, 0x00, 1024);
 227         size_t max_len = (len > 255) ? 255 : len;
 228         // max 255 bytes * 3 + 2 characters = 767 in buffer
 229         sprintf(tmp, "%.765s| ", sprint_hex(data, max_len) );
 230
 231         size_t i = 0;
 232         size_t pos = (max_len * 3)+2;
 233         // add another 255 characters ascii = 1020 characters of buffer used
 234         while(i < max_len) {
 235                 char c = data[i];
 236                 if ( (c < 32) || (c == 127))
 237                         c = '.';
 238                 sprintf(tmp+pos+i, "%c",  c);
 239                 ++i;
 240         }
 241         return buf;
 242 }
 243
 244 char *sprint_ascii_ex(const uint8_t *data, const size_t len, const size_t min_str_len) {
 245         static char buf[1024];
 246         char *tmp = buf;
 247         memset(buf, 0x00, 1024);
 248         size_t max_len = (len > 1010) ? 1010 : len;
 249         size_t i = 0;
 250         while(i < max_len){
 251                 char c = data[i];
 252                 tmp[i] = ((c < 32) || (c == 127)) ? '.' : c;
 253                 ++i;
 254         }
 255
 256         int minStrLen = min_str_len > i ? min_str_len : 0;
 257         for(; i < minStrLen; ++i)
 258                 tmp[i] = ' ';
 259
 260         return buf;
 261 }
 262
 263 char *sprint_ascii(const uint8_t *data, const size_t len) {
 264         return sprint_ascii_ex(data, len, 0);
 265 }
 266
 267 void num_to_bytes(uint64_t n, size_t len, uint8_t* dest)
 268 {
 269         while (len--) {
 270                 dest[len] = (uint8_t) n;
 271                 n >>= 8;
 272         }
 273 }
 274
 275 uint64_t bytes_to_num(uint8_t* src, size_t len)
 276 {
 277         uint64_t num = 0;
 278         while (len--)
 279         {
 280                 num = (num << 8) | (*src);
 281                 src++;
 282         }
 283         return num;
 284 }
 285
 286 void num_to_bytebits(uint64_t   n, size_t len, uint8_t *dest) {
 287         while (len--) {
 288                 dest[len] = n & 1;
 289                 n >>= 1;
 290         }
 291 }
 292
 293 //least significant bit first
 294 void num_to_bytebitsLSBF(uint64_t n, size_t len, uint8_t *dest) {
 295         for(int i = 0 ; i < len ; ++i) {
 296                 dest[i] =  n & 1;
 297                 n >>= 1;
 298         }
 299 }
 300
 301 // Swap bit order on a uint32_t value.  Can be limited by nrbits just use say 8bits reversal
 302 // And clears the rest of the bits.
 303 uint32_t SwapBits(uint32_t value, int nrbits) {
 304         uint32_t newvalue = 0;
 305         for(int i = 0; i < nrbits; i++) {
 306                 newvalue ^= ((value >> i) & 1) << (nrbits - 1 - i);
 307         }
 308         return newvalue;
 309 }
 310
 311 // aa,bb,cc,dd,ee,ff,gg,hh, ii,jj,kk,ll,mm,nn,oo,pp
 312 // to
 313 // hh,gg,ff,ee,dd,cc,bb,aa, pp,oo,nn,mm,ll,kk,jj,ii
 314 // up to 64 bytes or 512 bits
 315 uint8_t *SwapEndian64(const uint8_t *src, const size_t len, const uint8_t blockSize){
 316         static uint8_t buf[64];
 317         memset(buf, 0x00, 64);
 318         uint8_t *tmp = buf;
 319         for (uint8_t block=0; block < (uint8_t)(len/blockSize); block++){
 320                 for (size_t i = 0; i < blockSize; i++){
 321                         tmp[i+(blockSize*block)] = src[(blockSize-1-i)+(blockSize*block)];
 322                 }
 323         }
 324         return tmp;
 325 }
 326
 327 // takes a uint8_t src array, for len items and reverses the byte order in blocksizes (8,16,32,64),
 328 // returns: the dest array contains the reordered src array.
 329 void SwapEndian64ex(const uint8_t *src, const size_t len, const uint8_t blockSize, uint8_t *dest){
 330         for (uint8_t block=0; block < (uint8_t)(len/blockSize); block++){
 331                 for (size_t i = 0; i < blockSize; i++){
 332                         dest[i+(blockSize*block)] = src[(blockSize-1-i)+(blockSize*block)];
 333                 }
 334         }
 335 }
 336
 337 //assumes little endian
 338 char * printBits(size_t const size, void const * const ptr)
 339 {
 340     unsigned char *b = (unsigned char*) ptr;
 341     unsigned char byte;
 342         static char buf[1024];
 343         char * tmp = buf;
 344     int i, j;
 345
 346     for (i=size-1;i>=0;i--)
 347     {
 348         for (j=7;j>=0;j--)
 349         {
 350             byte = b[i] & (1<<j);
 351             byte >>= j;
 352             sprintf(tmp, "%u", (unsigned int)byte);
 353                         tmp++;
 354         }
 355     }
 356         return buf;
 357 }
 358
 359 char * printBitsPar(const uint8_t *b, size_t len) {
 360         static char buf1[512] = {0};
 361         static char buf2[512] = {0};
 362         static char *buf;
 363         if (buf != buf1)
 364                 buf = buf1;
 365         else
 366                 buf = buf2;
 367         memset(buf, 0x00, 512);
 368
 369         for (int i = 0; i < len; i++) {
 370                 buf[i] = ((b[i / 8] << (i % 8)) & 0x80) ? '1':'0';
 371         }
 372         return buf;
 373 }
 374
 375
 376 //  -------------------------------------------------------------------------
 377 //  string parameters lib
 378 //  -------------------------------------------------------------------------
 379
 380 //  -------------------------------------------------------------------------
 381 //  line     - param line
 382 //  bg, en   - symbol numbers in param line of beginning and ending parameter
 383 //  paramnum - param number (from 0)
 384 //  -------------------------------------------------------------------------
 385 int param_getptr(const char *line, int *bg, int *en, int paramnum)
 386 {
 387         int i;
 388         int len = strlen(line);
 389
 390         *bg = 0;
 391         *en = 0;
 392
 393   // skip spaces
 394         while (line[*bg] ==' ' || line[*bg]=='\t') (*bg)++;
 395         if (*bg >= len) {
 396                 return 1;
 397         }
 398
 399         for (i = 0; i < paramnum; i++) {
 400                 while (line[*bg]!=' ' && line[*bg]!='\t' && line[*bg] != '\0') (*bg)++;
 401                 while (line[*bg]==' ' || line[*bg]=='\t') (*bg)++;
 402
 403                 if (line[*bg] == '\0') return 1;
 404         }
 405
 406         *en = *bg;
 407         while (line[*en] != ' ' && line[*en] != '\t' && line[*en] != '\0') (*en)++;
 408
 409         (*en)--;
 410
 411         return 0;
 412 }
 413
 414
 415 int param_getlength(const char *line, int paramnum)
 416 {
 417         int bg, en;
 418
 419         if (param_getptr(line, &bg, &en, paramnum)) return 0;
 420
 421         return en - bg + 1;
 422 }
 423
 424 char param_getchar(const char *line, int paramnum) {
 425         return param_getchar_indx(line, 0, paramnum);
 426 }
 427
 428 char param_getchar_indx(const char *line, int indx, int paramnum) {
 429         int bg, en;
 430
 431         if (param_getptr(line, &bg, &en, paramnum)) return 0x00;
 432
 433         if (bg + indx > en)
 434                 return '\0';
 435
 436         return line[bg + indx];
 437 }
 438
 439 uint8_t param_get8(const char *line, int paramnum)
 440 {
 441         return param_get8ex(line, paramnum, 0, 10);
 442 }
 443
 444 /**
 445  * @brief Reads a decimal integer (actually, 0-254, not 255)
 446  * @param line
 447  * @param paramnum
 448  * @return -1 if error
 449  */
 450 uint8_t param_getdec(const char *line, int paramnum, uint8_t *destination)
 451 {
 452         uint8_t val =  param_get8ex(line, paramnum, 255, 10);
 453         if( (int8_t) val == -1) return 1;
 454         (*destination) = val;
 455         return 0;
 456 }
 457 /**
 458  * @brief Checks if param is decimal
 459  * @param line
 460  * @param paramnum
 461  * @return
 462  */
 463 uint8_t param_isdec(const char *line, int paramnum)
 464 {
 465         int bg, en;
 466         //TODO, check more thorougly
 467         if (!param_getptr(line, &bg, &en, paramnum)) return 1;
 468                 //              return strtoul(&line[bg], NULL, 10) & 0xff;
 469
 470         return 0;
 471 }
 472
 473 uint8_t param_get8ex(const char *line, int paramnum, int deflt, int base)
 474 {
 475         int bg, en;
 476
 477         if (!param_getptr(line, &bg, &en, paramnum))
 478                 return strtoul(&line[bg], NULL, base) & 0xff;
 479         else
 480                 return deflt;
 481 }
 482
 483 uint32_t param_get32ex(const char *line, int paramnum, int deflt, int base)
 484 {
 485         int bg, en;
 486
 487         if (!param_getptr(line, &bg, &en, paramnum))
 488                 return strtoul(&line[bg], NULL, base);
 489         else
 490                 return deflt;
 491 }
 492
 493 uint64_t param_get64ex(const char *line, int paramnum, int deflt, int base)
 494 {
 495         int bg, en;
 496
 497         if (!param_getptr(line, &bg, &en, paramnum))
 498                 return strtoull(&line[bg], NULL, base);
 499         else
 500                 return deflt;
 501 }
 502
 503 int param_gethex(const char *line, int paramnum, uint8_t * data, int hexcnt)
 504 {
 505         int bg, en, temp, i;
 506
 507         if (hexcnt % 2)
 508                 return 1;
 509
 510         if (param_getptr(line, &bg, &en, paramnum)) return 1;
 511
 512         if (en - bg + 1 != hexcnt)
 513                 return 1;
 514
 515         for(i = 0; i < hexcnt; i += 2) {
 516                 if (!(isxdigit((unsigned char)line[bg + i]) && isxdigit((unsigned char)line[bg + i + 1])) )     return 1;
 517
 518                 sscanf((char[]){line[bg + i], line[bg + i + 1], 0}, "%X", &temp);
 519                 data[i / 2] = temp & 0xff;
 520         }
 521
 522         return 0;
 523 }
 524 int param_gethex_ex(const char *line, int paramnum, uint8_t * data, int *hexcnt)
 525 {
 526         int bg, en, temp, i;
 527
 528         //if (hexcnt % 2)
 529         //      return 1;
 530
 531         if (param_getptr(line, &bg, &en, paramnum)) return 1;
 532
 533         *hexcnt = en - bg + 1;
 534         if (*hexcnt % 2) //error if not complete hex bytes
 535                 return 1;
 536
 537         for(i = 0; i < *hexcnt; i += 2) {
 538                 if (!(isxdigit((unsigned char)line[bg + i]) && isxdigit((unsigned char)line[bg + i + 1])) )     return 1;
 539
 540                 sscanf((char[]){line[bg + i], line[bg + i + 1], 0}, "%X", &temp);
 541                 data[i / 2] = temp & 0xff;
 542         }
 543
 544         return 0;
 545 }
 546
 547 int param_gethex_to_eol(const char *line, int paramnum, uint8_t * data, int maxdatalen, int *datalen) {
 548         int bg, en;
 549         uint32_t temp;
 550         char buf[5] = {0};
 551
 552         if (param_getptr(line, &bg, &en, paramnum)) return 1;
 553
 554         *datalen = 0;
 555
 556         int indx = bg;
 557         while (line[indx]) {
 558                 if (line[indx] == '\t' || line[indx] == ' ') {
 559                         indx++;
 560                         continue;
 561                 }
 562
 563                 if (isxdigit((unsigned char)line[indx])) {
 564                         buf[strlen(buf) + 1] = 0x00;
 565                         buf[strlen(buf)] = line[indx];
 566                 } else {
 567                         // if we have symbols other than spaces and hex
 568                         return 1;
 569                 }
 570
 571                 if (*datalen >= maxdatalen) {
 572                         // if we dont have space in buffer and have symbols to translate
 573                         return 2;
 574                 }
 575
 576                 if (strlen(buf) >= 2) {
 577                         sscanf(buf, "%x", &temp);
 578                         data[*datalen] = (uint8_t)(temp & 0xff);
 579                         *buf = 0;
 580                         (*datalen)++;
 581                 }
 582
 583                 indx++;
 584         }
 585
 586         if (strlen(buf) > 0)
 587                 //error when not completed hex bytes
 588                 return 3;
 589
 590         return 0;
 591 }
 592
 593 int param_getstr(const char *line, int paramnum, char * str, size_t buffersize)
 594 {
 595         int bg, en;
 596
 597         if (param_getptr(line, &bg, &en, paramnum)) {
 598                 return 0;
 599         }
 600
 601         // Prevent out of bounds errors
 602         if (en - bg + 1 >= buffersize) {
 603                 printf("out of bounds error: want %d bytes have %zd bytes\n", en - bg + 1 + 1, buffersize);
 604                 return 0;
 605         }
 606
 607         memcpy(str, line + bg, en - bg + 1);
 608         str[en - bg + 1] = 0;
 609
 610         return en - bg + 1;
 611 }
 612
 613 /*
 614 The following methods comes from Rfidler sourcecode.
 615 https://github.com/ApertureLabsLtd/RFIDler/blob/master/firmware/Pic32/RFIDler.X/src/
 616 */
 617
 618 // convert hex to sequence of 0/1 bit values
 619 // returns number of bits converted
 620 int hextobinarray(char *target, char *source)
 621 {
 622     int length, i, count= 0;
 623     char* start = source;
 624     char x;
 625
 626     length = strlen(source);
 627     // process 4 bits (1 hex digit) at a time
 628     while(length--)
 629     {
 630         x= *(source++);
 631         // capitalize
 632         if (x >= 'a' && x <= 'f')
 633             x -= 32;
 634         // convert to numeric value
 635         if (x >= '0' && x <= '9')
 636             x -= '0';
 637         else if (x >= 'A' && x <= 'F')
 638             x -= 'A' - 10;
 639         else {
 640                 printf("Discovered unknown character %c %d at idx %tu of %s\n", x, x, source - start, start);
 641             return 0;
 642         }
 643         // output
 644         for(i= 0 ; i < 4 ; ++i, ++count)
 645             *(target++)= (x >> (3 - i)) & 1;
 646     }
 647
 648     return count;
 649 }
 650
 651 // convert hex to human readable binary string
 652 int hextobinstring(char *target, char *source)
 653 {
 654     int length;
 655
 656     if(!(length= hextobinarray(target, source)))
 657         return 0;
 658     binarraytobinstring(target, target, length);
 659     return length;
 660 }
 661
 662 // convert binary array of 0x00/0x01 values to hex (safe to do in place as target will always be shorter than source)
 663 // return number of bits converted
 664 int binarraytohex(char *target,char *source, int length)
 665 {
 666     unsigned char i, x;
 667     int j = length;
 668
 669     if(j % 4)
 670         return 0;
 671
 672     while(j)
 673     {
 674         for(i= x= 0 ; i < 4 ; ++i)
 675             x +=  ( source[i] << (3 - i));
 676         sprintf(target,"%X", (unsigned int)x);
 677         ++target;
 678         source += 4;
 679         j -= 4;
 680     }
 681     return length;
 682 }
 683
 684 // convert binary array to human readable binary
 685 void binarraytobinstring(char *target, char *source,  int length)
 686 {
 687     int i;
 688
 689     for(i= 0 ; i < length ; ++i)
 690         *(target++)= *(source++) + '0';
 691     *target= '\0';
 692 }
 693
 694 // return parity bit required to match type
 695 uint8_t GetParity( uint8_t *bits, uint8_t type, int length)
 696 {
 697     int x;
 698
 699     for(x= 0 ; length > 0 ; --length)
 700         x += bits[length - 1];
 701     x %= 2;
 702
 703     return x ^ type;
 704 }
 705
 706 // add HID parity to binary array: EVEN prefix for 1st half of ID, ODD suffix for 2nd half
 707 void wiegand_add_parity(uint8_t *target, uint8_t *source, uint8_t length)
 708 {
 709     *(target++)= GetParity(source, EVEN, length / 2);
 710     memcpy(target, source, length);
 711     target += length;
 712     *(target)= GetParity(source + length / 2, ODD, length / 2);
 713 }
 714
 715 // xor two arrays together for len items.  The dst array contains the new xored values.
 716 void xor(unsigned char *dst, unsigned char *src, size_t len) {
 717    for( ; len > 0; len--,dst++,src++)
 718        *dst ^= *src;
 719 }
 720
 721 int32_t le24toh (uint8_t data[3]) {
 722     return (data[2] << 16) | (data[1] << 8) | data[0];
 723 }
 724 uint32_t le32toh (uint8_t *data) {
 725         return (uint32_t)( (data[3]<<24) | (data[2]<<16) | (data[1]<<8) | data[0]);
 726 }
 727
 728 // RotateLeft - Ultralight, Desfire, works on byte level
 729 // 00-01-02  >> 01-02-00
 730 void rol(uint8_t *data, const size_t len){
 731     uint8_t first = data[0];
 732     for (size_t i = 0; i < len-1; i++) {
 733         data[i] = data[i+1];
 734     }
 735     data[len-1] = first;
 736 }
 737
 738
 739 // Replace unprintable characters with a dot in char buffer
 740 void clean_ascii(unsigned char *buf, size_t len) {
 741   for (size_t i = 0; i < len; i++) {
 742     if (!isprint(buf[i]))
 743       buf[i] = '.';
 744   }
 745 }
 746
 747 // replace \r \n to \0
 748 void strcleanrn(char *buf, size_t len) {
 749         strcreplace(buf, len, '\n', '\0');
 750         strcreplace(buf, len, '\r', '\0');
 751 }
 752
 753 // replace char in buffer
 754 void strcreplace(char *buf, size_t len, char from, char to) {
 755   for (size_t i = 0; i < len; i++) {
 756     if (buf[i] == from)
 757       buf[i] = to;
 758   }
 759 }
 760
 761 char *strmcopy(char *buf) {
 762         char * str = NULL;
 763         if ((str = (char*) malloc(strlen(buf) + 1)) != NULL) {
 764                 memset(str, 0, strlen(buf) + 1);
 765                 strcpy(str, buf);
 766         }
 767         return str;
 768 }
 769
 770
 771 // determine number of logical CPU cores (use for multithreaded functions)
 772 extern int num_CPUs(void)
 773 {
 774 #if defined(_WIN32)
 775         #include <sysinfoapi.h>
 776         SYSTEM_INFO sysinfo;
 777         GetSystemInfo(&sysinfo);
 778         return sysinfo.dwNumberOfProcessors;
 779 #elif defined(__linux__) || defined(__APPLE__)
 780         #include <unistd.h>
 781         return sysconf(_SC_NPROCESSORS_ONLN);
 782 #else
 783         return 1;
 784 #endif
 785 }
 786