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 #include <stdarg.h>
  20
  21 #ifdef _WIN32
  22 #include <windows.h>
  23 #endif
  24
  25 #define MAX_BIN_BREAK_LENGTH   (3072+384+1)
  26
  27 #ifndef _WIN32
  28 #include <termios.h>
  29 #include <sys/ioctl.h>
  30 #include <unistd.h>
  31
  32 int ukbhit(void)
  33 {
  34   int cnt = 0;
  35   int error;
  36   static struct termios Otty, Ntty;
  37
  38   if ( tcgetattr(STDIN_FILENO, &Otty) == -1 ) return -1;
  39   Ntty = Otty;
  40
  41   Ntty.c_iflag          = 0x0000;   // input mode
  42   Ntty.c_oflag          = 0x0000;   // output mode
  43   Ntty.c_lflag         &= ~ICANON;  // control mode = raw
  44   Ntty.c_cc[VMIN]       = 1;        // return if at least 1 character is in the queue
  45   Ntty.c_cc[VTIME]      = 0;        // no timeout. Wait forever
  46
  47   if (0 == (error = tcsetattr(STDIN_FILENO, TCSANOW, &Ntty))) {   // set new attributes
  48     error += ioctl(STDIN_FILENO, FIONREAD, &cnt);                 // get number of characters availabe
  49     error += tcsetattr(STDIN_FILENO, TCSANOW, &Otty);             // reset attributes
  50   }
  51
  52   return ( error == 0 ? cnt : -1 );
  53 }
  54
  55 #else
  56
  57 #include <conio.h>
  58 int ukbhit(void) {
  59         return kbhit();
  60 }
  61 #endif
  62
  63 // log files functions
  64 void AddLogLine(char *file, char *extData, char *c) {
  65         FILE *fLog = NULL;
  66     char filename[FILE_PATH_SIZE] = {0x00};
  67     int len = 0;
  68
  69     len = strlen(file);
  70     if (len > FILE_PATH_SIZE) len = FILE_PATH_SIZE;
  71     memcpy(filename, file, len);
  72
  73         fLog = fopen(filename, "a");
  74         if (!fLog) {
  75                 printf("Could not append log file %s", filename);
  76                 return;
  77         }
  78
  79         fprintf(fLog, "%s", extData);
  80         fprintf(fLog, "%s\n", c);
  81         fclose(fLog);
  82 }
  83
  84 void AddLogHex(char *fileName, char *extData, const uint8_t * data, const size_t len){
  85         AddLogLine(fileName, extData, sprint_hex(data, len));
  86 }
  87
  88 void AddLogUint64(char *fileName, char *extData, const uint64_t data) {
  89   char buf[100] = {0};
  90         sprintf(buf, "%x%x", (unsigned int)((data & 0xFFFFFFFF00000000) >> 32), (unsigned int)(data & 0xFFFFFFFF));
  91         AddLogLine(fileName, extData, buf);
  92 }
  93
  94 void AddLogCurrentDT(char *fileName) {
  95         char buff[20];
  96         struct tm *curTime;
  97
  98         time_t now = time(0);
  99         curTime = gmtime(&now);
 100
 101         strftime (buff, sizeof(buff), "%Y-%m-%d %H:%M:%S", curTime);
 102         AddLogLine(fileName, "\nanticollision: ", buff);
 103 }
 104
 105 void FillFileNameByUID(char *fileName, uint8_t * uid, char *ext, int byteCount) {
 106         char * fnameptr = fileName;
 107         memset(fileName, 0x00, 200);
 108
 109         for (int j = 0; j < byteCount; j++, fnameptr += 2)
 110                 sprintf(fnameptr, "%02x", (unsigned int) uid[j]);
 111         sprintf(fnameptr, "%s", ext);
 112 }
 113
 114 // fill buffer from structure [{uint8_t data, size_t length},...]
 115 int FillBuffer(uint8_t *data, size_t maxDataLength, size_t *dataLength, ...) {
 116         *dataLength = 0;
 117         va_list valist;
 118         va_start(valist, dataLength);
 119
 120         uint8_t *vdata = NULL;
 121         size_t vlength = 0;
 122         do{
 123                 vdata = va_arg(valist, uint8_t *);
 124                 if (!vdata)
 125                         break;
 126
 127                 vlength = va_arg(valist, size_t);
 128                 if (*dataLength + vlength >  maxDataLength) {
 129                         va_end(valist);
 130                         return 1;
 131                 }
 132
 133                 memcpy(&data[*dataLength], vdata, vlength);
 134                 *dataLength += vlength;
 135
 136         } while (vdata);
 137
 138         va_end(valist);
 139
 140         return 0;
 141 }
 142
 143 bool CheckStringIsHEXValue(const char *value) {
 144         for (int i = 0; i < strlen(value); i++)
 145                 if (!isxdigit(value[i]))
 146                         return false;
 147
 148         if (strlen(value) % 2)
 149                 return false;
 150
 151         return true;
 152 }
 153
 154 void hex_to_buffer(const uint8_t *buf, const uint8_t *hex_data, const size_t hex_len, const size_t hex_max_len,
 155         const size_t min_str_len, const size_t spaces_between, bool uppercase) {
 156
 157         char *tmp = (char *)buf;
 158         size_t i;
 159         memset(tmp, 0x00, hex_max_len);
 160
 161         int maxLen = ( hex_len > hex_max_len) ? hex_max_len : hex_len;
 162
 163         for (i = 0; i < maxLen; ++i, tmp += 2 + spaces_between) {
 164                 sprintf(tmp, (uppercase) ? "%02X" : "%02x", (unsigned int) hex_data[i]);
 165
 166                 for (int j = 0; j < spaces_between; j++)
 167                         sprintf(tmp + 2 + j, " ");
 168         }
 169
 170         i *= (2 + spaces_between);
 171         int minStrLen = min_str_len > i ? min_str_len : 0;
 172         if (minStrLen > hex_max_len)
 173                 minStrLen = hex_max_len;
 174         for(; i < minStrLen; i++, tmp += 1)
 175                 sprintf(tmp, " ");
 176
 177         return;
 178 }
 179
 180 // printing and converting functions
 181
 182 char *sprint_hex(const uint8_t *data, const size_t len) {
 183         static char buf[4097] = {0};
 184
 185         hex_to_buffer((uint8_t *)buf, data, len, sizeof(buf) - 1, 0, 1, false);
 186
 187         return buf;
 188 }
 189
 190 char *sprint_hex_inrow_ex(const uint8_t *data, const size_t len, const size_t min_str_len) {
 191         static char buf[4097] = {0};
 192
 193         hex_to_buffer((uint8_t *)buf, data, len, sizeof(buf) - 1, min_str_len, 0, false);
 194
 195         return buf;
 196 }
 197
 198 char *sprint_hex_inrow(const uint8_t *data, const size_t len) {
 199         return sprint_hex_inrow_ex(data, len, 0);
 200 }
 201
 202 char *sprint_bin_break(const uint8_t *data, const size_t len, const uint8_t breaks) {
 203         // make sure we don't go beyond our char array memory
 204         int max_len;
 205         if (breaks==0)
 206                 max_len = ( len > MAX_BIN_BREAK_LENGTH ) ? MAX_BIN_BREAK_LENGTH : len;
 207         else
 208                 max_len = ( len+(len/breaks) > MAX_BIN_BREAK_LENGTH ) ? MAX_BIN_BREAK_LENGTH : len+(len/breaks);
 209
 210         static char buf[MAX_BIN_BREAK_LENGTH]; // 3072 + end of line characters if broken at 8 bits
 211         //clear memory
 212         memset(buf, 0x00, sizeof(buf));
 213         char *tmp = buf;
 214
 215         size_t in_index = 0;
 216         // loop through the out_index to make sure we don't go too far
 217         for (size_t out_index=0; out_index < max_len; out_index++) {
 218                 // set character - (should be binary but verify it isn't more than 1 digit)
 219                 if (data[in_index]<10)
 220                         sprintf(tmp++, "%u", (unsigned int) data[in_index]);
 221                 // check if a line break is needed and we have room to print it in our array
 222                 if ( (breaks > 0) && !((in_index+1) % breaks) && (out_index+1 < max_len) ) {
 223                         // increment and print line break
 224                         out_index++;
 225                         sprintf(tmp++, "%s","\n");
 226                 }
 227                 in_index++;
 228         }
 229
 230         return buf;
 231 }
 232
 233 char *sprint_bin(const uint8_t *data, const size_t len) {
 234         return sprint_bin_break(data, len, 0);
 235 }
 236
 237 char *sprint_ascii_ex(const uint8_t *data, const size_t len, const size_t min_str_len) {
 238         static char buf[1024];
 239         char *tmp = buf;
 240         memset(buf, 0x00, 1024);
 241         size_t max_len = (len > 1010) ? 1010 : len;
 242         size_t i = 0;
 243         while(i < max_len){
 244                 char c = data[i];
 245                 tmp[i] = ((c < 32) || (c == 127)) ? '.' : c;
 246                 ++i;
 247         }
 248
 249         int minStrLen = min_str_len > i ? min_str_len : 0;
 250         for(; i < minStrLen; ++i)
 251                 tmp[i] = ' ';
 252
 253         return buf;
 254 }
 255
 256 void num_to_bytes(uint64_t n, size_t len, uint8_t* dest)
 257 {
 258         while (len--) {
 259                 dest[len] = (uint8_t) n;
 260                 n >>= 8;
 261         }
 262 }
 263
 264 uint64_t bytes_to_num(uint8_t* src, size_t len)
 265 {
 266         uint64_t num = 0;
 267         while (len--)
 268         {
 269                 num = (num << 8) | (*src);
 270                 src++;
 271         }
 272         return num;
 273 }
 274
 275 void num_to_bytebits(uint64_t   n, size_t len, uint8_t *dest) {
 276         while (len--) {
 277                 dest[len] = n & 1;
 278                 n >>= 1;
 279         }
 280 }
 281
 282 //least significant bit first
 283 void num_to_bytebitsLSBF(uint64_t n, size_t len, uint8_t *dest) {
 284         for(int i = 0 ; i < len ; ++i) {
 285                 dest[i] =  n & 1;
 286                 n >>= 1;
 287         }
 288 }
 289
 290 // Swap bit order on a uint32_t value.  Can be limited by nrbits just use say 8bits reversal
 291 // And clears the rest of the bits.
 292 uint32_t SwapBits(uint32_t value, int nrbits) {
 293         uint32_t newvalue = 0;
 294         for(int i = 0; i < nrbits; i++) {
 295                 newvalue ^= ((value >> i) & 1) << (nrbits - 1 - i);
 296         }
 297         return newvalue;
 298 }
 299
 300 // aa,bb,cc,dd,ee,ff,gg,hh, ii,jj,kk,ll,mm,nn,oo,pp
 301 // to
 302 // hh,gg,ff,ee,dd,cc,bb,aa, pp,oo,nn,mm,ll,kk,jj,ii
 303 // up to 64 bytes or 512 bits
 304 uint8_t *SwapEndian64(const uint8_t *src, const size_t len, const uint8_t blockSize){
 305         static uint8_t buf[64];
 306         memset(buf, 0x00, 64);
 307         uint8_t *tmp = buf;
 308         for (uint8_t block=0; block < (uint8_t)(len/blockSize); block++){
 309                 for (size_t i = 0; i < blockSize; i++){
 310                         tmp[i+(blockSize*block)] = src[(blockSize-1-i)+(blockSize*block)];
 311                 }
 312         }
 313         return tmp;
 314 }
 315
 316 //assumes little endian
 317 char * printBits(size_t const size, void const * const ptr)
 318 {
 319     unsigned char *b = (unsigned char*) ptr;
 320     unsigned char byte;
 321         static char buf[1024];
 322         char * tmp = buf;
 323     int i, j;
 324
 325     for (i=size-1;i>=0;i--)
 326     {
 327         for (j=7;j>=0;j--)
 328         {
 329             byte = b[i] & (1<<j);
 330             byte >>= j;
 331             sprintf(tmp, "%u", (unsigned int)byte);
 332                         tmp++;
 333         }
 334     }
 335         return buf;
 336 }
 337
 338 char * printBitsPar(const uint8_t *b, size_t len) {
 339         static char buf1[512] = {0};
 340         static char buf2[512] = {0};
 341         static char *buf;
 342         if (buf != buf1)
 343                 buf = buf1;
 344         else
 345                 buf = buf2;
 346         memset(buf, 0x00, 512);
 347
 348         for (int i = 0; i < len; i++) {
 349                 buf[i] = ((b[i / 8] << (i % 8)) & 0x80) ? '1':'0';
 350         }
 351         return buf;
 352 }
 353
 354
 355 //  -------------------------------------------------------------------------
 356 //  string parameters lib
 357 //  -------------------------------------------------------------------------
 358
 359 //  -------------------------------------------------------------------------
 360 //  line     - param line
 361 //  bg, en   - symbol numbers in param line of beginning and ending parameter
 362 //  paramnum - param number (from 0)
 363 //  -------------------------------------------------------------------------
 364 int param_getptr(const char *line, int *bg, int *en, int paramnum)
 365 {
 366         int i;
 367         int len = strlen(line);
 368
 369         *bg = 0;
 370         *en = 0;
 371
 372   // skip spaces
 373         while (line[*bg] ==' ' || line[*bg]=='\t') (*bg)++;
 374         if (*bg >= len) {
 375                 return 1;
 376         }
 377
 378         for (i = 0; i < paramnum; i++) {
 379                 while (line[*bg]!=' ' && line[*bg]!='\t' && line[*bg] != '\0') (*bg)++;
 380                 while (line[*bg]==' ' || line[*bg]=='\t') (*bg)++;
 381
 382                 if (line[*bg] == '\0') return 1;
 383         }
 384
 385         *en = *bg;
 386         while (line[*en] != ' ' && line[*en] != '\t' && line[*en] != '\0') (*en)++;
 387
 388         (*en)--;
 389
 390         return 0;
 391 }
 392
 393
 394 int param_getlength(const char *line, int paramnum)
 395 {
 396         int bg, en;
 397
 398         if (param_getptr(line, &bg, &en, paramnum)) return 0;
 399
 400         return en - bg + 1;
 401 }
 402
 403 char param_getchar(const char *line, int paramnum) {
 404         return param_getchar_indx(line, 0, paramnum);
 405 }
 406
 407 char param_getchar_indx(const char *line, int indx, int paramnum) {
 408         int bg, en;
 409
 410         if (param_getptr(line, &bg, &en, paramnum)) return 0x00;
 411
 412         if (bg + indx > en)
 413                 return '\0';
 414
 415         return line[bg + indx];
 416 }
 417
 418 uint8_t param_get8(const char *line, int paramnum)
 419 {
 420         return param_get8ex(line, paramnum, 0, 10);
 421 }
 422
 423 /**
 424  * @brief Reads a decimal integer (actually, 0-254, not 255)
 425  * @param line
 426  * @param paramnum
 427  * @return -1 if error
 428  */
 429 uint8_t param_getdec(const char *line, int paramnum, uint8_t *destination)
 430 {
 431         uint8_t val =  param_get8ex(line, paramnum, 255, 10);
 432         if( (int8_t) val == -1) return 1;
 433         (*destination) = val;
 434         return 0;
 435 }
 436 /**
 437  * @brief Checks if param is decimal
 438  * @param line
 439  * @param paramnum
 440  * @return
 441  */
 442 uint8_t param_isdec(const char *line, int paramnum)
 443 {
 444         int bg, en;
 445         //TODO, check more thorougly
 446         if (!param_getptr(line, &bg, &en, paramnum)) return 1;
 447                 //              return strtoul(&line[bg], NULL, 10) & 0xff;
 448
 449         return 0;
 450 }
 451
 452 uint8_t param_get8ex(const char *line, int paramnum, int deflt, int base)
 453 {
 454         int bg, en;
 455
 456         if (!param_getptr(line, &bg, &en, paramnum))
 457                 return strtoul(&line[bg], NULL, base) & 0xff;
 458         else
 459                 return deflt;
 460 }
 461
 462 uint32_t param_get32ex(const char *line, int paramnum, int deflt, int base)
 463 {
 464         int bg, en;
 465
 466         if (!param_getptr(line, &bg, &en, paramnum))
 467                 return strtoul(&line[bg], NULL, base);
 468         else
 469                 return deflt;
 470 }
 471
 472 uint64_t param_get64ex(const char *line, int paramnum, int deflt, int base)
 473 {
 474         int bg, en;
 475
 476         if (!param_getptr(line, &bg, &en, paramnum))
 477                 return strtoull(&line[bg], NULL, base);
 478         else
 479                 return deflt;
 480 }
 481
 482 int param_gethex(const char *line, int paramnum, uint8_t * data, int hexcnt)
 483 {
 484         int bg, en, temp, i;
 485
 486         if (hexcnt % 2)
 487                 return 1;
 488
 489         if (param_getptr(line, &bg, &en, paramnum)) return 1;
 490
 491         if (en - bg + 1 != hexcnt)
 492                 return 1;
 493
 494         for(i = 0; i < hexcnt; i += 2) {
 495                 if (!(isxdigit((unsigned char)line[bg + i]) && isxdigit((unsigned char)line[bg + i + 1])) )     return 1;
 496
 497                 sscanf((char[]){line[bg + i], line[bg + i + 1], 0}, "%X", &temp);
 498                 data[i / 2] = temp & 0xff;
 499         }
 500
 501         return 0;
 502 }
 503 int param_gethex_ex(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         *hexcnt = en - bg + 1;
 513         if (*hexcnt % 2) //error if not complete hex bytes
 514                 return 1;
 515
 516         for(i = 0; i < *hexcnt; i += 2) {
 517                 if (!(isxdigit((unsigned char)line[bg + i]) && isxdigit((unsigned char)line[bg + i + 1])) )     return 1;
 518
 519                 sscanf((char[]){line[bg + i], line[bg + i + 1], 0}, "%X", &temp);
 520                 data[i / 2] = temp & 0xff;
 521         }
 522
 523         return 0;
 524 }
 525
 526 int param_gethex_to_eol(const char *line, int paramnum, uint8_t * data, int maxdatalen, int *datalen) {
 527         int bg, en;
 528         uint32_t temp;
 529         char buf[5] = {0};
 530
 531         if (param_getptr(line, &bg, &en, paramnum)) return 1;
 532
 533         *datalen = 0;
 534
 535         int indx = bg;
 536         while (line[indx]) {
 537                 if (line[indx] == '\t' || line[indx] == ' ') {
 538                         indx++;
 539                         continue;
 540                 }
 541
 542                 if (isxdigit((unsigned char)line[indx])) {
 543                         buf[strlen(buf) + 1] = 0x00;
 544                         buf[strlen(buf)] = line[indx];
 545                 } else {
 546                         // if we have symbols other than spaces and hex
 547                         return 1;
 548                 }
 549
 550                 if (*datalen >= maxdatalen) {
 551                         // if we dont have space in buffer and have symbols to translate
 552                         return 2;
 553                 }
 554
 555                 if (strlen(buf) >= 2) {
 556                         sscanf(buf, "%x", &temp);
 557                         data[*datalen] = (uint8_t)(temp & 0xff);
 558                         *buf = 0;
 559                         (*datalen)++;
 560                 }
 561
 562                 indx++;
 563         }
 564
 565         if (strlen(buf) > 0)
 566                 //error when not completed hex bytes
 567                 return 3;
 568
 569         return 0;
 570 }
 571
 572 int param_getstr(const char *line, int paramnum, char * str, size_t buffersize)
 573 {
 574         int bg, en;
 575
 576         if (param_getptr(line, &bg, &en, paramnum)) {
 577                 return 0;
 578         }
 579
 580         // Prevent out of bounds errors
 581         if (en - bg + 1 >= buffersize) {
 582                 printf("out of bounds error: want %d bytes have %zd bytes\n", en - bg + 1 + 1, buffersize);
 583                 return 0;
 584         }
 585
 586         memcpy(str, line + bg, en - bg + 1);
 587         str[en - bg + 1] = 0;
 588
 589         return en - bg + 1;
 590 }
 591
 592 /*
 593 The following methods comes from Rfidler sourcecode.
 594 https://github.com/ApertureLabsLtd/RFIDler/blob/master/firmware/Pic32/RFIDler.X/src/
 595 */
 596
 597 // convert hex to sequence of 0/1 bit values
 598 // returns number of bits converted
 599 int hextobinarray(char *target, char *source)
 600 {
 601     int length, i, count= 0;
 602     char* start = source;
 603     char x;
 604
 605     length = strlen(source);
 606     // process 4 bits (1 hex digit) at a time
 607     while(length--)
 608     {
 609         x= *(source++);
 610         // capitalize
 611         if (x >= 'a' && x <= 'f')
 612             x -= 32;
 613         // convert to numeric value
 614         if (x >= '0' && x <= '9')
 615             x -= '0';
 616         else if (x >= 'A' && x <= 'F')
 617             x -= 'A' - 10;
 618         else {
 619                 printf("Discovered unknown character %c %d at idx %tu of %s\n", x, x, source - start, start);
 620             return 0;
 621         }
 622         // output
 623         for(i= 0 ; i < 4 ; ++i, ++count)
 624             *(target++)= (x >> (3 - i)) & 1;
 625     }
 626
 627     return count;
 628 }
 629
 630 // convert binary array of 0x00/0x01 values to hex (safe to do in place as target will always be shorter than source)
 631 // return number of bits converted
 632 int binarraytohex(char *target,char *source, int length)
 633 {
 634     unsigned char i, x;
 635     int j = length;
 636
 637     if(j % 4)
 638         return 0;
 639
 640     while(j)
 641     {
 642         for(i= x= 0 ; i < 4 ; ++i)
 643             x +=  ( source[i] << (3 - i));
 644         sprintf(target,"%X", (unsigned int)x);
 645         ++target;
 646         source += 4;
 647         j -= 4;
 648     }
 649     return length;
 650 }
 651
 652 // return parity bit required to match type
 653 uint8_t GetParity( uint8_t *bits, uint8_t type, int length)
 654 {
 655     int x;
 656
 657     for(x= 0 ; length > 0 ; --length)
 658         x += bits[length - 1];
 659     x %= 2;
 660
 661     return x ^ type;
 662 }
 663
 664 // add HID parity to binary array: EVEN prefix for 1st half of ID, ODD suffix for 2nd half
 665 void wiegand_add_parity(uint8_t *target, uint8_t *source, uint8_t length)
 666 {
 667     *(target++)= GetParity(source, EVEN, length / 2);
 668     memcpy(target, source, length);
 669     target += length;
 670     *(target)= GetParity(source + length / 2, ODD, length / 2);
 671 }
 672
 673 // xor two arrays together for len items.  The dst array contains the new xored values.
 674 void xor(unsigned char *dst, unsigned char *src, size_t len) {
 675    for( ; len > 0; len--,dst++,src++)
 676        *dst ^= *src;
 677 }
 678
 679 // RotateLeft - Ultralight, Desfire, works on byte level
 680 // 00-01-02  >> 01-02-00
 681 void rol(uint8_t *data, const size_t len){
 682     uint8_t first = data[0];
 683     for (size_t i = 0; i < len-1; i++) {
 684         data[i] = data[i+1];
 685     }
 686     data[len-1] = first;
 687 }
 688
 689
 690 // Replace unprintable characters with a dot in char buffer
 691 void clean_ascii(unsigned char *buf, size_t len) {
 692   for (size_t i = 0; i < len; i++) {
 693     if (!isprint(buf[i]))
 694       buf[i] = '.';
 695   }
 696 }
 697
 698 // replace \r \n to \0
 699 void strcleanrn(char *buf, size_t len) {
 700         strcreplace(buf, len, '\n', '\0');
 701         strcreplace(buf, len, '\r', '\0');
 702 }
 703
 704 // replace char in buffer
 705 void strcreplace(char *buf, size_t len, char from, char to) {
 706   for (size_t i = 0; i < len; i++) {
 707     if (buf[i] == from)
 708       buf[i] = to;
 709   }
 710 }
 711
 712 char *strmcopy(char *buf) {
 713         char * str = NULL;
 714         if ((str = (char*) malloc(strlen(buf) + 1)) != NULL) {
 715                 memset(str, 0, strlen(buf) + 1);
 716                 strcpy(str, buf);
 717         }
 718         return str;
 719 }
 720
 721
 722 // determine number of logical CPU cores (use for multithreaded functions)
 723 extern int num_CPUs(void)
 724 {
 725 #if defined(_WIN32)
 726         #include <sysinfoapi.h>
 727         SYSTEM_INFO sysinfo;
 728         GetSystemInfo(&sysinfo);
 729         return sysinfo.dwNumberOfProcessors;
 730 #elif defined(__linux__) || defined(__APPLE__)
 731         #include <unistd.h>
 732         return sysconf(_SC_NPROCESSORS_ONLN);
 733 #else
 734         return 1;
 735 #endif
 736 }
 737