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

   1 //-----------------------------------------------------------------------------
   2 // Copyright (C) 2015 iceman <iceman at iuse.se>
   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 // CRC Calculations from the software reveng commands
   9 //-----------------------------------------------------------------------------
  10
  11 #include <stdlib.h>
  12 #ifdef _WIN32
  13 #  include <io.h>
  14 #  include <fcntl.h>
  15 #  ifndef STDIN_FILENO
  16 #    define STDIN_FILENO 0
  17 #  endif /* STDIN_FILENO */
  18 #endif /* _WIN32 */
  19
  20 #include <stdio.h>
  21 #include <string.h>
  22 //#include <stdlib.h>
  23 //#include <ctype.h>
  24 #include "cmdmain.h"
  25 #include "cmdcrc.h"
  26 #include "reveng/reveng.h"
  27 #include "ui.h"
  28 #include "util.h"
  29
  30 #define MAX_ARGS 20
  31
  32 int uerr(char *msg){
  33         PrintAndLog("%s",msg);
  34         return 0;
  35 }
  36
  37 int split(char *str, char *arr[MAX_ARGS]){
  38     int beginIndex = 0;
  39     int endIndex;
  40     int maxWords = MAX_ARGS;
  41     int wordCnt = 0;
  42
  43     while(1){
  44         while(isspace(str[beginIndex])){
  45             ++beginIndex;
  46         }
  47         if(str[beginIndex] == '\0')
  48             break;
  49         endIndex = beginIndex;
  50         while (str[endIndex] && !isspace(str[endIndex])){
  51             ++endIndex;
  52         }
  53         int len = endIndex - beginIndex;
  54         char *tmp = calloc(len + 1, sizeof(char));
  55         memcpy(tmp, &str[beginIndex], len);
  56         arr[wordCnt++] = tmp;
  57         //PrintAndLog("cnt: %d, %s",wordCnt-1, arr[wordCnt-1]);
  58         beginIndex = endIndex;
  59         if (wordCnt == maxWords)
  60             break;
  61     }
  62     return wordCnt;
  63 }
  64
  65 int CmdCrc(const char *Cmd)
  66 {
  67         char name[] = {"reveng "};
  68         char Cmd2[50 + 7];
  69         memcpy(Cmd2, name, 7);
  70         memcpy(Cmd2 + 7, Cmd, 50);
  71         char *argv[MAX_ARGS];
  72         int argc = split(Cmd2, argv);
  73
  74         if (argc == 3 && memcmp(argv[1],"-g",2)==0) {
  75                 CmdrevengSearch(argv[2]);
  76         } else {
  77         reveng_main(argc, argv);
  78         }
  79         //PrintAndLog("DEBUG argc: %d, %s %s Cmd: %s",argc, argv[0], Cmd2, Cmd);
  80         for(int i = 0; i < argc; ++i){
  81                 free(argv[i]);
  82         }
  83
  84   return 0;
  85 }
  86
  87 //returns array of model names and the count of models returning
  88 //  as well as a width array for the width of each model
  89 int GetModels(char *Models[], int *count, uint8_t *width){
  90         /* default values */
  91         static model_t model = {
  92                 PZERO,          /* no CRC polynomial, user must specify */
  93                 PZERO,          /* Init = 0 */
  94                 P_BE,           /* RefIn = false, RefOut = false, plus P_RTJUST setting in reveng.h */
  95                 PZERO,          /* XorOut = 0 */
  96                 PZERO,          /* check value unused */
  97                 NULL            /* no model name */
  98         };
  99
 100         int ibperhx = 8;//, obperhx = 8;
 101         int rflags = 0, uflags = 0; /* search and UI flags */
 102         poly_t apoly, crc, qpoly = PZERO, *apolys = NULL, *pptr = NULL, *qptr = NULL;
 103         model_t pset = model, *candmods, *mptr;
 104
 105         /* stdin must be binary */
 106         #ifdef _WIN32
 107                 _setmode(STDIN_FILENO, _O_BINARY);
 108         #endif /* _WIN32 */
 109
 110         SETBMP();
 111
 112         int args = 0, psets, pass;
 113         int Cnt = 0;
 114         if (width[0] == 0) { //reveng -D
 115                 *count = mcount();
 116                 if(!*count)
 117                         return uerr("no preset models available");
 118
 119                 for(int mode = 0; mode < *count; ++mode) {
 120                         mbynum(&model, mode);
 121                         mcanon(&model);
 122                         size_t size = (model.name && *model.name) ? strlen(model.name) : 6;
 123                         char *tmp = calloc(size+1, sizeof(char));
 124                         if (tmp==NULL)
 125                                 return uerr("out of memory?");
 126
 127                         memcpy(tmp, model.name, size);
 128                         Models[mode] = tmp;
 129                         width[mode] = plen(model.spoly);
 130                 }
 131                 mfree(&model);
 132         } else { //reveng -s
 133
 134                         if(~model.flags & P_MULXN)
 135                                 return uerr("cannot search for non-Williams compliant models");
 136
 137                 praloc(&model.spoly, (unsigned long)width[0]);
 138                 praloc(&model.init, (unsigned long)width[0]);
 139                 praloc(&model.xorout, (unsigned long)width[0]);
 140                         if(!plen(model.spoly))
 141                         palloc(&model.spoly, (unsigned long)width[0]);
 142                         else
 143                         width[0] = (uint8_t)plen(model.spoly);
 144
 145                         /* special case if qpoly is zero, search to end of range */
 146                         if(!ptst(qpoly))
 147                                 rflags &= ~R_HAVEQ;
 148
 149                         /* if endianness not specified, try
 150                          * little-endian then big-endian.
 151                          * NB: crossed-endian algorithms will not be
 152                          * searched.
 153                          */
 154                         /* scan against preset models */
 155                         if(~uflags & C_FORCE) {
 156                                 pass = 0;
 157                                 Cnt = 0;
 158                                 do {
 159                                         psets = mcount();
 160
 161                                         while(psets) {
 162                                                 mbynum(&pset, --psets);
 163
 164                                                 /* skip if different width, or refin or refout don't match */
 165                                         if(plen(pset.spoly) != width[0] || (model.flags ^ pset.flags) & (P_REFIN | P_REFOUT))
 166                                                         continue;
 167                                                 /* skip if the preset doesn't match specified parameters */
 168                                                 if(rflags & R_HAVEP && pcmp(&model.spoly, &pset.spoly))
 169                                                         continue;
 170                                                 if(rflags & R_HAVEI && psncmp(&model.init, &pset.init))
 171                                                         continue;
 172                                                 if(rflags & R_HAVEX && psncmp(&model.xorout, &pset.xorout))
 173                                                         continue;
 174
 175                                         //for additional args (not used yet, maybe future?)
 176                                                 apoly = pclone(pset.xorout);
 177                                                 if(pset.flags & P_REFOUT)
 178                                                         prev(&apoly);
 179
 180                                                 for(qptr = apolys; qptr < pptr; ++qptr) {
 181                                                         crc = pcrc(*qptr, pset.spoly, pset.init, apoly, 0);
 182                                                         if(ptst(crc)) {
 183                                                                 pfree(&crc);
 184                                                                 break;
 185                                                         } else
 186                                                                 pfree(&crc);
 187                                                 }
 188                                                 pfree(&apoly);
 189                                                 if(qptr == pptr) {
 190
 191                                                         /* the selected model solved all arguments */
 192
 193                                                         mcanon(&pset);
 194
 195                                                         size_t size = (pset.name && *pset.name) ? strlen(pset.name) : 6;
 196                                                         //PrintAndLog("Size: %d, %s, count: %d",size,pset.name, Cnt);
 197                                                         char *tmp = calloc(size+1, sizeof(char));
 198                                                         if (tmp == NULL){
 199                                                                 PrintAndLog("out of memory?");
 200                                                                 return 0;
 201                                                         }
 202                                                 width[Cnt] = width[0];
 203                                                         memcpy(tmp, pset.name, size);
 204                                                         Models[Cnt++] = tmp;
 205                                                         *count = Cnt;
 206                                                         uflags |= C_RESULT;
 207                                                 }
 208                                         }
 209                                         mfree(&pset);
 210
 211                                         /* toggle refIn/refOut and reflect arguments */
 212                                         if(~rflags & R_HAVERI) {
 213                                                 model.flags ^= P_REFIN | P_REFOUT;
 214                                                 for(qptr = apolys; qptr < pptr; ++qptr)
 215                                                         prevch(qptr, ibperhx);
 216                                         }
 217                                 } while(~rflags & R_HAVERI && ++pass < 2);
 218                         }
 219                 //got everything now free the memory...
 220
 221                         if(uflags & C_RESULT) {
 222                                 for(qptr = apolys; qptr < pptr; ++qptr)
 223                                         pfree(qptr);
 224                         }
 225                         if(!(model.flags & P_REFIN) != !(model.flags & P_REFOUT))
 226                                 return uerr("cannot search for crossed-endian models");
 227
 228                         pass = 0;
 229                         do {
 230                                 mptr = candmods = reveng(&model, qpoly, rflags, args, apolys);
 231                                 if(mptr && plen(mptr->spoly))
 232                                         uflags |= C_RESULT;
 233                                 while(mptr && plen(mptr->spoly)) {
 234                                         mfree(mptr++);
 235                                 }
 236                                 free(candmods);
 237                                 if(~rflags & R_HAVERI) {
 238                                         model.flags ^= P_REFIN | P_REFOUT;
 239                                         for(qptr = apolys; qptr < pptr; ++qptr)
 240                                                 prevch(qptr, ibperhx);
 241                                 }
 242                         } while(~rflags & R_HAVERI && ++pass < 2);
 243                         for(qptr = apolys; qptr < pptr; ++qptr)
 244                                 pfree(qptr);
 245                         free(apolys);
 246                         if(~uflags & C_RESULT)
 247                                 return uerr("no models found");
 248                         mfree(&model);
 249
 250         }
 251         return 1;
 252 }
 253
 254 //-c || -v
 255 //inModel = valid model name string - CRC-8
 256 //inHexStr = input hex string to calculate crc on
 257 //reverse = reverse calc option if true
 258 //endian = {0 = calc default endian input and output, b = big endian input and output, B = big endian output, r = right justified
 259 //          l = little endian input and output, L = little endian output only, t = left justified}
 260 //result = calculated crc hex string
 261 int RunModel(char *inModel, char *inHexStr, bool reverse, char endian, char *result){
 262         /* default values */
 263         static model_t model = {
 264                 PZERO,          // no CRC polynomial, user must specify
 265                 PZERO,          // Init = 0
 266                 P_BE,             // RefIn = false, RefOut = false, plus P_RTJUST setting in reveng.h
 267                 PZERO,          // XorOut = 0
 268                 PZERO,          // check value unused
 269                 NULL              // no model name
 270         };
 271         int ibperhx = 8, obperhx = 8;
 272         int rflags = 0; // search flags
 273         int c;
 274         poly_t apoly, crc;
 275
 276         char *string;
 277
 278         // stdin must be binary
 279         #ifdef _WIN32
 280                 _setmode(STDIN_FILENO, _O_BINARY);
 281         #endif /* _WIN32 */
 282
 283         SETBMP();
 284         //set model
 285         if(!(c = mbynam(&model, inModel))) {
 286                 PrintAndLog("error: preset model '%s' not found.  Use reveng -D to list presets.", inModel);
 287                 return 0;
 288         }
 289         if(c < 0)
 290                 return uerr("no preset models available");
 291
 292         rflags |= R_HAVEP | R_HAVEI | R_HAVERI | R_HAVERO | R_HAVEX;
 293
 294         //set flags
 295         switch (endian) {
 296                 case 'b': /* b  big-endian (RefIn = false, RefOut = false ) */
 297                         model.flags &= ~P_REFIN;
 298                         rflags |= R_HAVERI;
 299                         /* fall through: */
 300                 case 'B': /* B  big-endian output (RefOut = false) */
 301                         model.flags &= ~P_REFOUT;
 302                         rflags |= R_HAVERO;
 303                         mnovel(&model);
 304                         /* fall through: */
 305                 case 'r': /* r  right-justified */
 306                         model.flags |= P_RTJUST;
 307                         break;
 308                 case 'l': /* l  little-endian input and output */
 309                         model.flags |= P_REFIN;
 310                         rflags |= R_HAVERI;
 311                         /* fall through: */
 312                 case 'L': /* L  little-endian output */
 313                         model.flags |= P_REFOUT;
 314                         rflags |= R_HAVERO;
 315                         mnovel(&model);
 316                         /* fall through: */
 317                 case 't': /* t  left-justified */
 318                         model.flags &= ~P_RTJUST;
 319                         break;
 320         }
 321
 322         mcanon(&model);
 323
 324         if (reverse) {
 325                 // v  calculate reversed CRC
 326                 /* Distinct from the -V switch as this causes
 327                  * the arguments and output to be reversed as well.
 328                  */
 329                 // reciprocate Poly
 330                 prcp(&model.spoly);
 331
 332                 /* mrev() does:
 333                  *   if(refout) prev(init); else prev(xorout);
 334                  * but here the entire argument polynomial is
 335                  * reflected, not just the characters, so RefIn
 336                  * and RefOut are not inverted as with -V.
 337                  * Consequently Init is the mirror image of the
 338                  * one resulting from -V, and so we have:
 339                  */
 340                 if(~model.flags & P_REFOUT) {
 341                         prev(&model.init);
 342                         prev(&model.xorout);
 343                 }
 344
 345                 // swap init and xorout
 346                 apoly = model.init;
 347                 model.init = model.xorout;
 348                 model.xorout = apoly;
 349         }
 350         // c  calculate CRC
 351
 352         /* in the Williams model, xorout is applied after the refout stage.
 353          * as refout is part of ptostr(), we reverse xorout here.
 354          */
 355         if(model.flags & P_REFOUT)
 356                 prev(&model.xorout);
 357
 358         apoly = strtop(inHexStr, model.flags, ibperhx);
 359
 360         if(reverse)
 361                 prev(&apoly);
 362
 363         crc = pcrc(apoly, model.spoly, model.init, model.xorout, model.flags);
 364
 365         if(reverse)
 366                 prev(&crc);
 367
 368         string = ptostr(crc, model.flags, obperhx);
 369         for (int i = 0; i < 50; i++){
 370                 result[i] = string[i];
 371                 if (result[i]==0) break;
 372         }
 373         free(string);
 374         pfree(&crc);
 375         pfree(&apoly);
 376         return 1;
 377 }
 378 //returns a calloced string (needs to be freed)
 379 char *SwapEndianStr(const char *inStr, const size_t len, const uint8_t blockSize){
 380         char *tmp = calloc(len+1, sizeof(char));
 381         for (uint8_t block=0; block < (uint8_t)(len/blockSize); block++){
 382                 for (size_t i = 0; i < blockSize; i+=2){
 383                         tmp[i+(blockSize*block)] = inStr[(blockSize-1-i-1)+(blockSize*block)];
 384                         tmp[i+(blockSize*block)+1] = inStr[(blockSize-1-i)+(blockSize*block)];
 385                 }
 386         }
 387         return tmp;
 388 }
 389
 390 // takes hex string in and searches for a matching result (hex string must include checksum)
 391 int CmdrevengSearch(const char *Cmd){
 392         char inHexStr[50] = {0x00};
 393         int dataLen = param_getstr(Cmd, 0, inHexStr);
 394         if (dataLen < 4) return 0;
 395
 396         char *Models[80];
 397         int count = 0;
 398         uint8_t width[80];
 399         width[0] = 0;
 400         uint8_t crcChars = 0;
 401         char result[30];
 402         char revResult[30];
 403         int ans = GetModels(Models, &count, width);
 404         bool found = false;
 405         if (!ans) return 0;
 406
 407         // try each model and get result
 408         for (int i = 0; i < count; i++){
 409                 /*if (found) {
 410                         free(Models[i]);
 411                         continue;
 412                 }*/
 413                 // round up to # of characters in this model's crc
 414                 crcChars = ((width[i]+7)/8)*2;
 415                 // can't test a model that has more crc digits than our data
 416                 if (crcChars >= dataLen)
 417                         continue;
 418                 memset(result, 0, 30);
 419                 char *inCRC = calloc(crcChars+1, sizeof(char));
 420                 memcpy(inCRC, inHexStr+(dataLen-crcChars), crcChars);
 421
 422                 char *outHex = calloc(dataLen-crcChars+1, sizeof(char));
 423                 memcpy(outHex, inHexStr, dataLen-crcChars);
 424
 425                 //PrintAndLog("DEBUG: dataLen: %d, crcChars: %d, Model: %s, CRC: %s, width: %d, outHex: %s",dataLen, crcChars, Models[i], inCRC, width[i], outHex);
 426                 ans = RunModel(Models[i], outHex, false, 0, result);
 427                 if (ans) {
 428                         //test for match
 429                         if (memcmp(result, inCRC, crcChars)==0){
 430                                 PrintAndLog("\nFound a possible match!\nModel: %s\nValue: %s\n",Models[i], result);
 431                                 //optional - stop searching if found...
 432                                 found = true;
 433                         } else {
 434                                 if (crcChars > 2){
 435                                         char *swapEndian = SwapEndianStr(result, crcChars, crcChars);
 436                                         if (memcmp(swapEndian, inCRC, crcChars)==0){
 437                                                 PrintAndLog("\nFound a possible match!\nModel: %s\nValue EndianSwapped: %s\n",Models[i], swapEndian);
 438                                                 //optional - stop searching if found...
 439                                                 found = true;
 440                                         }
 441                                         free(swapEndian);
 442                                 }
 443                         }
 444                 }
 445
 446                 //if (!found){
 447                         ans = RunModel(Models[i], outHex, true, 0, revResult);
 448                         if (ans) {
 449                                 //test for match
 450                                 if (memcmp(revResult, inCRC, crcChars)==0){
 451                                         PrintAndLog("\nFound a possible match!\nModel Reversed: %s\nValue: %s\n",Models[i], revResult);
 452                                         //optional - stop searching if found...
 453                                         found = true;
 454                                 } else {
 455                                         if (crcChars > 2){
 456                                                 char *swapEndian = SwapEndianStr(revResult, crcChars, crcChars);
 457                                                 if (memcmp(swapEndian, inCRC, crcChars)==0){
 458                                                         PrintAndLog("\nFound a possible match!\nModel Reversed: %s\nValue EndianSwapped: %s\n",Models[i], swapEndian);
 459                                                         //optional - stop searching if found...
 460                                                         found = true;
 461                                                 }
 462                                                 free(swapEndian);
 463                                         }
 464                                 }
 465                         }
 466                 //}
 467                 free(inCRC);
 468                 free(outHex);
 469                 free(Models[i]);
 470         }
 471         if (!found) PrintAndLog("\nNo matches found\n");
 472         return 1;
 473 }