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 "cmdmain.h"
  23 #include "cmdcrc.h"
  24 #include "reveng/reveng.h"
  25 #include "ui.h"
  26 #include "util.h"
  27
  28 #define MAX_ARGS 20
  29
  30 int uerr(char *msg){
  31         PrintAndLog("%s",msg);
  32         return 0;
  33 }
  34
  35 int split(char *str, char *arr[MAX_ARGS]){
  36     int beginIndex = 0;
  37     int endIndex;
  38     int maxWords = MAX_ARGS;
  39     int wordCnt = 0;
  40
  41     while(1){
  42         while(isspace(str[beginIndex])){
  43             ++beginIndex;
  44         }
  45         if(str[beginIndex] == '\0')
  46             break;
  47         endIndex = beginIndex;
  48         while (str[endIndex] && !isspace(str[endIndex])){
  49             ++endIndex;
  50         }
  51         int len = endIndex - beginIndex;
  52         char *tmp = calloc(len + 1, sizeof(char));
  53         memcpy(tmp, &str[beginIndex], len);
  54         arr[wordCnt++] = tmp;
  55         //PrintAndLog("cnt: %d, %s",wordCnt-1, arr[wordCnt-1]);
  56         beginIndex = endIndex;
  57         if (wordCnt == maxWords)
  58             break;
  59     }
  60     return wordCnt;
  61 }
  62
  63 int CmdCrc(const char *Cmd)
  64 {
  65         char name[] = {"reveng "};
  66         char Cmd2[50 + 7];
  67         memcpy(Cmd2, name, 7);
  68         memcpy(Cmd2 + 7, Cmd, 50);
  69         char *argv[MAX_ARGS];
  70         int argc = split(Cmd2, argv);
  71
  72         if (argc == 3 && memcmp(argv[1],"-g",2)==0) {
  73                 CmdrevengSearch(argv[2]);
  74         } else {
  75                 reveng_main(argc, argv);
  76         }
  77         //PrintAndLog("DEBUG argc: %d, %s %s Cmd: %s",argc, argv[0], Cmd2, Cmd);
  78         for(int i = 0; i < argc; ++i) {
  79                 free(argv[i]);
  80         }
  81
  82   return 0;
  83 }
  84
  85 //returns array of model names and the count of models returning
  86 //  as well as a width array for the width of each model
  87 int GetModels(char *Models[], int *count, uint8_t *width){
  88         /* default values */
  89         static model_t model = {
  90                 PZERO,          /* no CRC polynomial, user must specify */
  91                 PZERO,          /* Init = 0 */
  92                 P_BE,           /* RefIn = false, RefOut = false, plus P_RTJUST setting in reveng.h */
  93                 PZERO,          /* XorOut = 0 */
  94                 PZERO,          /* check value unused */
  95                 NULL            /* no model name */
  96         };
  97
  98         int ibperhx = 8;//, obperhx = 8;
  99         int rflags = 0, uflags = 0; /* search and UI flags */
 100         poly_t apoly, crc, qpoly = PZERO, *apolys = NULL, *pptr = NULL, *qptr = NULL;
 101         model_t pset = model, *candmods, *mptr;
 102
 103         /* stdin must be binary */
 104         #ifdef _WIN32
 105                 _setmode(STDIN_FILENO, _O_BINARY);
 106         #endif /* _WIN32 */
 107
 108         SETBMP();
 109
 110         int args = 0, psets, pass;
 111         int Cnt = 0;
 112         if (width[0] == 0) { //reveng -D
 113                 *count = mcount();
 114                 if(!*count)
 115                         return uerr("no preset models available");
 116
 117                 for(int mode = 0; mode < *count; ++mode) {
 118                         mbynum(&model, mode);
 119                         mcanon(&model);
 120                         size_t size = (model.name && *model.name) ? strlen(model.name) : 6;
 121                         char *tmp = calloc(size+1, sizeof(char));
 122                         if (tmp==NULL)
 123                                 return uerr("out of memory?");
 124
 125                         memcpy(tmp, model.name, size);
 126                         Models[mode] = tmp;
 127                         width[mode] = plen(model.spoly);
 128                 }
 129                 mfree(&model);
 130         } else { //reveng -s
 131
 132                 if(~model.flags & P_MULXN)
 133                         return uerr("cannot search for non-Williams compliant models");
 134
 135                 praloc(&model.spoly, (unsigned long)width[0]);
 136                 praloc(&model.init, (unsigned long)width[0]);
 137                 praloc(&model.xorout, (unsigned long)width[0]);
 138
 139                 if(!plen(model.spoly))
 140                         palloc(&model.spoly, (unsigned long)width[0]);
 141                 else
 142                         width[0] = (uint8_t)plen(model.spoly);
 143
 144                 /* special case if qpoly is zero, search to end of range */
 145                 if(!ptst(qpoly))
 146                         rflags &= ~R_HAVEQ;
 147
 148                 /* if endianness not specified, try
 149                  * little-endian then big-endian.
 150                  * NB: crossed-endian algorithms will not be
 151                  * searched.
 152                  */
 153                 /* scan against preset models */
 154                 if(~uflags & C_FORCE) {
 155                         pass = 0;
 156                         Cnt = 0;
 157                         do {
 158                                 psets = mcount();
 159
 160                                 while(psets) {
 161                                         mbynum(&pset, --psets);
 162
 163                                         /* skip if different width, or refin or refout don't match */
 164                                 if(plen(pset.spoly) != width[0] || (model.flags ^ pset.flags) & (P_REFIN | P_REFOUT))
 165                                                 continue;
 166                                         /* skip if the preset doesn't match specified parameters */
 167                                         if(rflags & R_HAVEP && pcmp(&model.spoly, &pset.spoly))
 168                                                 continue;
 169                                         if(rflags & R_HAVEI && psncmp(&model.init, &pset.init))
 170                                                 continue;
 171                                         if(rflags & R_HAVEX && psncmp(&model.xorout, &pset.xorout))
 172                                                 continue;
 173
 174                                 //for additional args (not used yet, maybe future?)
 175                                         apoly = pclone(pset.xorout);
 176                                         if(pset.flags & P_REFOUT)
 177                                                 prev(&apoly);
 178
 179                                         for(qptr = apolys; qptr < pptr; ++qptr) {
 180                                                 crc = pcrc(*qptr, pset.spoly, pset.init, apoly, 0);
 181                                                 if(ptst(crc)) {
 182                                                         pfree(&crc);
 183                                                         break;
 184                                                 } else
 185                                                         pfree(&crc);
 186                                         }
 187                                         pfree(&apoly);
 188                                         if(qptr == pptr) {
 189
 190                                                 /* the selected model solved all arguments */
 191
 192                                                 mcanon(&pset);
 193
 194                                                 size_t size = (pset.name && *pset.name) ? strlen(pset.name) : 6;
 195                                                 //PrintAndLog("Size: %d, %s, count: %d",size,pset.name, Cnt);
 196                                                 char *tmp = calloc(size+1, sizeof(char));
 197                                                 if (tmp == NULL){
 198                                                         PrintAndLog("out of memory?");
 199                                                         return 0;
 200                                                 }
 201                                         width[Cnt] = width[0];
 202                                                 memcpy(tmp, pset.name, size);
 203                                                 Models[Cnt++] = tmp;
 204                                                 *count = Cnt;
 205                                                 uflags |= C_RESULT;
 206                                         }
 207                                 }
 208                                 mfree(&pset);
 209
 210                                 /* toggle refIn/refOut and reflect arguments */
 211                                 if(~rflags & R_HAVERI) {
 212                                         model.flags ^= P_REFIN | P_REFOUT;
 213                                         for(qptr = apolys; qptr < pptr; ++qptr)
 214                                                 prevch(qptr, ibperhx);
 215                                 }
 216                         } while(~rflags & R_HAVERI && ++pass < 2);
 217                 }
 218                 //got everything now free the memory...
 219
 220                 if(uflags & C_RESULT) {
 221                         for(qptr = apolys; qptr < pptr; ++qptr)
 222                                 pfree(qptr);
 223                 }
 224                 if(!(model.flags & P_REFIN) != !(model.flags & P_REFOUT))
 225                         return uerr("cannot search for crossed-endian models");
 226
 227                 pass = 0;
 228                 do {
 229                         mptr = candmods = reveng(&model, qpoly, rflags, args, apolys);
 230                         if(mptr && plen(mptr->spoly))
 231                                 uflags |= C_RESULT;
 232                         while(mptr && plen(mptr->spoly)) {
 233                                 mfree(mptr++);
 234                         }
 235                         free(candmods);
 236                         if(~rflags & R_HAVERI) {
 237                                 model.flags ^= P_REFIN | P_REFOUT;
 238                                 for(qptr = apolys; qptr < pptr; ++qptr)
 239                                         prevch(qptr, ibperhx);
 240                         }
 241                 } while(~rflags & R_HAVERI && ++pass < 2);
 242                 for(qptr = apolys; qptr < pptr; ++qptr)
 243                         pfree(qptr);
 244                 free(apolys);
 245                 if(~uflags & C_RESULT)
 246                         return uerr("no models found");
 247                 mfree(&model);
 248
 249         }
 250         return 1;
 251 }
 252
 253 //-c || -v
 254 //inModel = valid model name string - CRC-8
 255 //inHexStr = input hex string to calculate crc on
 256 //reverse = reverse calc option if true
 257 //endian = {0 = calc default endian input and output, b = big endian input and output, B = big endian output, r = right justified
 258 //          l = little endian input and output, L = little endian output only, t = left justified}
 259 //result = calculated crc hex string
 260 int RunModel(char *inModel, char *inHexStr, bool reverse, char endian, char *result){
 261         /* default values */
 262         static model_t model = {
 263                 PZERO,          // no CRC polynomial, user must specify
 264                 PZERO,          // Init = 0
 265                 P_BE,             // RefIn = false, RefOut = false, plus P_RTJUST setting in reveng.h
 266                 PZERO,          // XorOut = 0
 267                 PZERO,          // check value unused
 268                 NULL              // no model name
 269         };
 270         int ibperhx = 8, obperhx = 8;
 271         int rflags = 0; // search flags
 272         int c;
 273         poly_t apoly, crc;
 274
 275         char *string;
 276
 277         // stdin must be binary
 278         #ifdef _WIN32
 279                 _setmode(STDIN_FILENO, _O_BINARY);
 280         #endif /* _WIN32 */
 281
 282         SETBMP();
 283         //set model
 284         if(!(c = mbynam(&model, inModel))) {
 285                 PrintAndLog("error: preset model '%s' not found.  Use reveng -D to list presets.", inModel);
 286                 return 0;
 287         }
 288         if(c < 0)
 289                 return uerr("no preset models available");
 290
 291         rflags |= R_HAVEP | R_HAVEI | R_HAVERI | R_HAVERO | R_HAVEX;
 292
 293         //set flags
 294         switch (endian) {
 295                 case 'b': /* b  big-endian (RefIn = false, RefOut = false ) */
 296                         model.flags &= ~P_REFIN;
 297                         rflags |= R_HAVERI;
 298                         /* fall through: */
 299                 case 'B': /* B  big-endian output (RefOut = false) */
 300                         model.flags &= ~P_REFOUT;
 301                         rflags |= R_HAVERO;
 302                         mnovel(&model);
 303                         /* fall through: */
 304                 case 'r': /* r  right-justified */
 305                         model.flags |= P_RTJUST;
 306                         break;
 307                 case 'l': /* l  little-endian input and output */
 308                         model.flags |= P_REFIN;
 309                         rflags |= R_HAVERI;
 310                         /* fall through: */
 311                 case 'L': /* L  little-endian output */
 312                         model.flags |= P_REFOUT;
 313                         rflags |= R_HAVERO;
 314                         mnovel(&model);
 315                         /* fall through: */
 316                 case 't': /* t  left-justified */
 317                         model.flags &= ~P_RTJUST;
 318                         break;
 319         }
 320         /* canonicalise the model, so the one we dump is the one we
 321          * calculate with (not with -s, spoly may be blank which will
 322          * normalise to zero and clear init and xorout.)
 323          */
 324         mcanon(&model);
 325
 326
 327         if (reverse) {
 328                 // v  calculate reversed CRC
 329                 /* Distinct from the -V switch as this causes
 330                  * the arguments and output to be reversed as well.
 331                  */
 332                 // reciprocate Poly
 333                 prcp(&model.spoly);
 334
 335                 /* mrev() does:
 336                  *   if(refout) prev(init); else prev(xorout);
 337                  * but here the entire argument polynomial is
 338                  * reflected, not just the characters, so RefIn
 339                  * and RefOut are not inverted as with -V.
 340                  * Consequently Init is the mirror image of the
 341                  * one resulting from -V, and so we have:
 342                  */
 343                 if(~model.flags & P_REFOUT) {
 344                         prev(&model.init);
 345                         prev(&model.xorout);
 346                 }
 347
 348                 // swap init and xorout
 349                 apoly = model.init;
 350                 model.init = model.xorout;
 351                 model.xorout = apoly;
 352         }
 353         // c  calculate CRC
 354
 355         /* in the Williams model, xorout is applied after the refout stage.
 356          * as refout is part of ptostr(), we reverse xorout here.
 357          */
 358         if(model.flags & P_REFOUT)
 359                 prev(&model.xorout);
 360
 361         apoly = strtop(inHexStr, model.flags, ibperhx);
 362
 363         if(reverse)
 364                 prev(&apoly);
 365
 366         crc = pcrc(apoly, model.spoly, model.init, model.xorout, model.flags);
 367
 368         if(reverse)
 369                 prev(&crc);
 370
 371         string = ptostr(crc, model.flags, obperhx);
 372         for (int i = 0; i < 50; i++){
 373                 result[i] = string[i];
 374                 if (result[i]==0) break;
 375         }
 376         free(string);
 377         pfree(&crc);
 378         pfree(&apoly);
 379         return 1;
 380 }
 381 //returns a calloced string (needs to be freed)
 382 char *SwapEndianStr(const char *inStr, const size_t len, const uint8_t blockSize){
 383         char *tmp = calloc(len+1, sizeof(char));
 384         for (uint8_t block=0; block < (uint8_t)(len/blockSize); block++){
 385                 for (size_t i = 0; i < blockSize; i+=2){
 386                         tmp[i+(blockSize*block)] = inStr[(blockSize-1-i-1)+(blockSize*block)];
 387                         tmp[i+(blockSize*block)+1] = inStr[(blockSize-1-i)+(blockSize*block)];
 388                 }
 389         }
 390         return tmp;
 391 }
 392
 393 // takes hex string in and searches for a matching result (hex string must include checksum)
 394 int CmdrevengSearch(const char *Cmd){
 395         char inHexStr[50] = {0x00};
 396         int dataLen = param_getstr(Cmd, 0, inHexStr);
 397         if (dataLen < 4) return 0;
 398
 399         char *Models[80];
 400         int count = 0;
 401         uint8_t width[80];
 402         width[0] = 0;
 403         uint8_t crcChars = 0;
 404         char result[30];
 405         char revResult[30];
 406         int ans = GetModels(Models, &count, width);
 407         bool found = false;
 408         if (!ans) return 0;
 409
 410         // try each model and get result
 411         for (int i = 0; i < count; i++){
 412                 /*if (found) {
 413                         free(Models[i]);
 414                         continue;
 415                 }*/
 416                 // round up to # of characters in this model's crc
 417                 crcChars = ((width[i]+7)/8)*2;
 418                 // can't test a model that has more crc digits than our data
 419                 if (crcChars >= dataLen)
 420                         continue;
 421                 memset(result, 0, 30);
 422                 char *inCRC = calloc(crcChars+1, sizeof(char));
 423                 memcpy(inCRC, inHexStr+(dataLen-crcChars), crcChars);
 424
 425                 char *outHex = calloc(dataLen-crcChars+1, sizeof(char));
 426                 memcpy(outHex, inHexStr, dataLen-crcChars);
 427
 428                 //PrintAndLog("DEBUG: dataLen: %d, crcChars: %d, Model: %s, CRC: %s, width: %d, outHex: %s",dataLen, crcChars, Models[i], inCRC, width[i], outHex);
 429                 ans = RunModel(Models[i], outHex, false, 0, result);
 430                 if (ans) {
 431                         //test for match
 432                         if (memcmp(result, inCRC, crcChars)==0){
 433                                 PrintAndLog("\nFound a possible match!\nModel: %s\nValue: %s\n",Models[i], result);
 434                                 //optional - stop searching if found...
 435                                 found = true;
 436                         } else {
 437                                 if (crcChars > 2){
 438                                         char *swapEndian = SwapEndianStr(result, crcChars, crcChars);
 439                                         if (memcmp(swapEndian, inCRC, crcChars)==0){
 440                                                 PrintAndLog("\nFound a possible match!\nModel: %s\nValue EndianSwapped: %s\n",Models[i], swapEndian);
 441                                                 //optional - stop searching if found...
 442                                                 found = true;
 443                                         }
 444                                         free(swapEndian);
 445                                 }
 446                         }
 447                 }
 448
 449                 //if (!found){
 450                         ans = RunModel(Models[i], outHex, true, 0, revResult);
 451                         if (ans) {
 452                                 //test for match
 453                                 if (memcmp(revResult, inCRC, crcChars)==0){
 454                                         PrintAndLog("\nFound a possible match!\nModel Reversed: %s\nValue: %s\n",Models[i], revResult);
 455                                         //optional - stop searching if found...
 456                                         found = true;
 457                                 } else {
 458                                         if (crcChars > 2){
 459                                                 char *swapEndian = SwapEndianStr(revResult, crcChars, crcChars);
 460                                                 if (memcmp(swapEndian, inCRC, crcChars)==0){
 461                                                         PrintAndLog("\nFound a possible match!\nModel Reversed: %s\nValue EndianSwapped: %s\n",Models[i], swapEndian);
 462                                                         //optional - stop searching if found...
 463                                                         found = true;
 464                                                 }
 465                                                 free(swapEndian);
 466                                         }
 467                                 }
 468                         }
 469                 //}
 470                 free(inCRC);
 471                 free(outHex);
 472                 free(Models[i]);
 473         }
 474         if (!found) PrintAndLog("\nNo matches found\n");
 475         return 1;
 476 }