cvs.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                 }
  48         endIndex = beginIndex;
  49         while (str[endIndex] && !isspace(str[endIndex])) {
  50             ++endIndex;
  51         }
  52         int len = endIndex - beginIndex;
  53         char *tmp = calloc(len + 1, sizeof(char));
  54         memcpy(tmp, &str[beginIndex], len);
  55         arr[wordCnt++] = tmp;
  56         //PrintAndLog("cnt: %d, %s",wordCnt-1, arr[wordCnt-1]);
  57         beginIndex = endIndex;
  58         if (wordCnt == maxWords)
  59             break;
  60     }
  61     return wordCnt;
  62 }
  63
  64 int CmdCrc(const char *Cmd)
  65 {
  66         char name[] = {"reveng "};
  67         char Cmd2[50 + 7];
  68         memcpy(Cmd2, name, 7);
  69         memcpy(Cmd2 + 7, Cmd, 50);
  70         char *argv[MAX_ARGS];
  71         int argc = split(Cmd2, argv);
  72
  73         if (argc == 3 && memcmp(argv[1],"-g",2)==0) {
  74                 CmdrevengSearch(argv[2]);
  75         } else {
  76                 reveng_main(argc, argv);
  77         }
  78         //PrintAndLog("DEBUG argc: %d, %s %s Cmd: %s",argc, argv[0], Cmd2, Cmd);
  79         for(int i = 0; i < argc; ++i) {
  80                 free(argv[i]);
  81         }
  82
  83   return 0;
  84 }
  85
  86 //returns array of model names and the count of models returning
  87 //  as well as a width array for the width of each model
  88 int GetModels(char *Models[], int *count, uint8_t *width){
  89         /* default values */
  90         static model_t model = {
  91                 PZERO,          /* no CRC polynomial, user must specify */
  92                 PZERO,          /* Init = 0 */
  93                 P_BE,           /* RefIn = false, RefOut = false, plus P_RTJUST setting in reveng.h */
  94                 PZERO,          /* XorOut = 0 */
  95                 PZERO,          /* check value unused */
  96                 NULL            /* no model name */
  97         };
  98
  99         int ibperhx = 8;//, obperhx = 8;
 100         int rflags = 0, uflags = 0; /* search and UI flags */
 101         poly_t apoly, crc, qpoly = PZERO, *apolys = NULL, *pptr = NULL, *qptr = NULL;
 102         model_t pset = model, *candmods, *mptr;
 103
 104         /* stdin must be binary */
 105         #ifdef _WIN32
 106                 _setmode(STDIN_FILENO, _O_BINARY);
 107         #endif /* _WIN32 */
 108
 109         SETBMP();
 110
 111         int args = 0, psets, pass;
 112         int Cnt = 0;
 113         if (width[0] == 0) { //reveng -D
 114                 *count = mcount();
 115                 if(!*count)
 116                         return uerr("no preset models available");
 117
 118                 for(int mode = 0; mode < *count; ++mode) {
 119                         mbynum(&model, mode);
 120                         mcanon(&model);
 121                         size_t size = (model.name && *model.name) ? strlen(model.name) : 6;
 122                         char *tmp = calloc(size+1, sizeof(char));
 123                         if (tmp==NULL)
 124                                 return uerr("out of memory?");
 125
 126                         memcpy(tmp, model.name, size);
 127                         Models[mode] = tmp;
 128                         width[mode] = plen(model.spoly);
 129                 }
 130                 mfree(&model);
 131         } else { //reveng -s
 132
 133                 if(~model.flags & P_MULXN)
 134                         return uerr("cannot search for non-Williams compliant models");
 135
 136                 praloc(&model.spoly, (unsigned long)width[0]);
 137                 praloc(&model.init, (unsigned long)width[0]);
 138                 praloc(&model.xorout, (unsigned long)width[0]);
 139
 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
 178                                         if (pset.flags & P_REFOUT)
 179                                                 prev(&apoly);
 180
 181
 182                                         for (qptr = apolys; qptr < pptr; ++qptr) {
 183                                                 crc = pcrc(*qptr, pset.spoly, pset.init, apoly, 0);
 184                                                 if (ptst(crc)) {
 185                                                         pfree(&crc);
 186                                                         break;
 187                                                 }
 188                                                 pfree(&crc);
 189                                         }
 190                                         pfree(&apoly);
 191
 192                                         if (qptr == pptr) {
 193
 194                                                 /* the selected model solved all arguments */
 195                                                 mcanon(&pset);
 196
 197                                                 size_t size = (pset.name && *pset.name) ? strlen(pset.name) : 6;
 198                                                 //PrintAndLog("Size: %d, %s, count: %d",size,pset.name, Cnt);
 199                                                 char *tmp = calloc(size+1, sizeof(char));
 200                                                 if (tmp == NULL){
 201                                                         PrintAndLog("out of memory?");
 202                                                         return 0;
 203                                                 }
 204                                                 width[Cnt] = width[0];
 205                                                 memcpy(tmp, pset.name, size);
 206                                                 Models[Cnt++] = tmp;
 207                                                 *count = Cnt;
 208                                                 uflags |= C_RESULT;
 209                                         }
 210                                 }
 211                                 mfree(&pset);
 212
 213                                 /* toggle refIn/refOut and reflect arguments */
 214                                 if (~rflags & R_HAVERI) {
 215                                         model.flags ^= P_REFIN | P_REFOUT;
 216                                         for (qptr = apolys; qptr < pptr; ++qptr) {
 217                                                 prevch(qptr, ibperhx);
 218                                         }
 219                                 }
 220                         } while (~rflags & R_HAVERI && ++pass < 2);
 221                 }
 222                 //got everything now free the memory...
 223
 224                 if (uflags & C_RESULT) {
 225                         for (qptr = apolys; qptr < pptr; ++qptr) {
 226                                 pfree(qptr);
 227                         }
 228                 }
 229                 if (!(model.flags & P_REFIN) != !(model.flags & P_REFOUT))
 230                         return uerr("cannot search for crossed-endian models");
 231
 232                 pass = 0;
 233                 do {
 234                         mptr = candmods = reveng(&model, qpoly, rflags, args, apolys);
 235                         if (mptr && plen(mptr->spoly)) {
 236                                 uflags |= C_RESULT;
 237                         }
 238                         while (mptr && plen(mptr->spoly)) {
 239                                 mfree(mptr++);
 240                         }
 241                         free(candmods);
 242                         if (~rflags & R_HAVERI) {
 243                                 model.flags ^= P_REFIN | P_REFOUT;
 244                                 for (qptr = apolys; qptr < pptr; ++qptr) {
 245                                         prevch(qptr, ibperhx);
 246                                 }
 247                         }
 248                 } while (~rflags & R_HAVERI && ++pass < 2);
 249
 250                 for (qptr = apolys; qptr < pptr; ++qptr) {
 251                         pfree(qptr);
 252                 }
 253                 free(apolys);
 254                 if (~uflags & C_RESULT)
 255                         return uerr("no models found");
 256
 257                 mfree(&model);
 258         }
 259         return 1;
 260 }
 261
 262 //-c || -v
 263 //inModel = valid model name string - CRC-8
 264 //inHexStr = input hex string to calculate crc on
 265 //reverse = reverse calc option if true
 266 //endian = {0 = calc default endian input and output, b = big endian input and output, B = big endian output, r = right justified
 267 //          l = little endian input and output, L = little endian output only, t = left justified}
 268 //result = calculated crc hex string
 269 int RunModel(char *inModel, char *inHexStr, bool reverse, char endian, char *result){
 270         /* default values */
 271         static model_t model = {
 272                 PZERO,          // no CRC polynomial, user must specify
 273                 PZERO,          // Init = 0
 274                 P_BE,             // RefIn = false, RefOut = false, plus P_RTJUST setting in reveng.h
 275                 PZERO,          // XorOut = 0
 276                 PZERO,          // check value unused
 277                 NULL              // no model name
 278         };
 279         int ibperhx = 8, obperhx = 8;
 280         int rflags = 0; // search flags
 281         int c;
 282         poly_t apoly, crc;
 283
 284         char *string;
 285
 286         // stdin must be binary
 287         #ifdef _WIN32
 288                 _setmode(STDIN_FILENO, _O_BINARY);
 289         #endif /* _WIN32 */
 290
 291         SETBMP();
 292         //set model
 293         if (!(c = mbynam(&model, inModel))) {
 294                 PrintAndLog("error: preset model '%s' not found.  Use reveng -D to list presets.", inModel);
 295                 return 0;
 296         }
 297         if (c < 0)
 298                 return uerr("no preset models available");
 299
 300         rflags |= R_HAVEP | R_HAVEI | R_HAVERI | R_HAVERO | R_HAVEX;
 301
 302         //set flags
 303         switch (endian) {
 304                 case 'b': /* b  big-endian (RefIn = false, RefOut = false ) */
 305                         model.flags &= ~P_REFIN;
 306                         rflags |= R_HAVERI;
 307                         /* fall through: */
 308                 case 'B': /* B  big-endian output (RefOut = false) */
 309                         model.flags &= ~P_REFOUT;
 310                         rflags |= R_HAVERO;
 311                         mnovel(&model);
 312                         /* fall through: */
 313                 case 'r': /* r  right-justified */
 314                         model.flags |= P_RTJUST;
 315                         break;
 316                 case 'l': /* l  little-endian input and output */
 317                         model.flags |= P_REFIN;
 318                         rflags |= R_HAVERI;
 319                         /* fall through: */
 320                 case 'L': /* L  little-endian output */
 321                         model.flags |= P_REFOUT;
 322                         rflags |= R_HAVERO;
 323                         mnovel(&model);
 324                         /* fall through: */
 325                 case 't': /* t  left-justified */
 326                         model.flags &= ~P_RTJUST;
 327                         break;
 328         }
 329         /* canonicalise the model, so the one we dump is the one we
 330          * calculate with (not with -s, spoly may be blank which will
 331          * normalise to zero and clear init and xorout.)
 332          */
 333         mcanon(&model);
 334
 335
 336         if (reverse) {
 337                 // v  calculate reversed CRC
 338                 /* Distinct from the -V switch as this causes
 339                  * the arguments and output to be reversed as well.
 340                  */
 341                 // reciprocate Poly
 342                 prcp(&model.spoly);
 343
 344                 /* mrev() does:
 345                  *   if(refout) prev(init); else prev(xorout);
 346                  * but here the entire argument polynomial is
 347                  * reflected, not just the characters, so RefIn
 348                  * and RefOut are not inverted as with -V.
 349                  * Consequently Init is the mirror image of the
 350                  * one resulting from -V, and so we have:
 351                  */
 352                 if (~model.flags & P_REFOUT) {
 353                         prev(&model.init);
 354                         prev(&model.xorout);
 355                 }
 356
 357                 // swap init and xorout
 358                 apoly = model.init;
 359                 model.init = model.xorout;
 360                 model.xorout = apoly;
 361         }
 362         // c  calculate CRC
 363
 364         /* in the Williams model, xorout is applied after the refout stage.
 365          * as refout is part of ptostr(), we reverse xorout here.
 366          */
 367         if (model.flags & P_REFOUT)
 368                 prev(&model.xorout);
 369
 370         apoly = strtop(inHexStr, model.flags, ibperhx);
 371
 372         if (reverse)
 373                 prev(&apoly);
 374
 375         crc = pcrc(apoly, model.spoly, model.init, model.xorout, model.flags);
 376
 377         if (reverse)
 378                 prev(&crc);
 379
 380         string = ptostr(crc, model.flags, obperhx);
 381         for (int i = 0; i < 50; i++){
 382                 result[i] = string[i];
 383                 if (result[i]==0) break;
 384         }
 385         free(string);
 386         pfree(&crc);
 387         pfree(&apoly);
 388         return 1;
 389 }
 390 //returns a calloced string (needs to be freed)
 391 char *SwapEndianStr(const char *inStr, const size_t len, const uint8_t blockSize){
 392         char *tmp = calloc(len+1, sizeof(char));
 393         for (uint8_t block=0; block < (uint8_t)(len/blockSize); block++){
 394                 for (size_t i = 0; i < blockSize; i+=2){
 395                         tmp[i+(blockSize*block)] = inStr[(blockSize-1-i-1)+(blockSize*block)];
 396                         tmp[i+(blockSize*block)+1] = inStr[(blockSize-1-i)+(blockSize*block)];
 397                 }
 398         }
 399         return tmp;
 400 }
 401
 402 // takes hex string in and searches for a matching result (hex string must include checksum)
 403 int CmdrevengSearch(const char *Cmd){
 404         char inHexStr[50] = {0x00};
 405         int dataLen = param_getstr(Cmd, 0, inHexStr);
 406         if (dataLen < 4) return 0;
 407
 408         char *Models[80];
 409         int count = 0;
 410         uint8_t width[80];
 411         width[0] = 0;
 412         uint8_t crcChars = 0;
 413         char result[30];
 414         char revResult[30];
 415         int ans = GetModels(Models, &count, width);
 416         bool found = false;
 417         if (!ans) return 0;
 418
 419         // try each model and get result
 420         for (int i = 0; i < count; i++){
 421                 /*if (found) {
 422                         free(Models[i]);
 423                         continue;
 424                 }*/
 425                 // round up to # of characters in this model's crc
 426                 crcChars = ((width[i]+7)/8)*2;
 427                 // can't test a model that has more crc digits than our data
 428                 if (crcChars >= dataLen)
 429                         continue;
 430                 memset(result, 0, 30);
 431                 char *inCRC = calloc(crcChars+1, sizeof(char));
 432                 memcpy(inCRC, inHexStr+(dataLen-crcChars), crcChars);
 433
 434                 char *outHex = calloc(dataLen-crcChars+1, sizeof(char));
 435                 memcpy(outHex, inHexStr, dataLen-crcChars);
 436
 437                 //PrintAndLog("DEBUG: dataLen: %d, crcChars: %d, Model: %s, CRC: %s, width: %d, outHex: %s",dataLen, crcChars, Models[i], inCRC, width[i], outHex);
 438                 ans = RunModel(Models[i], outHex, false, 0, result);
 439                 if (ans) {
 440                         //test for match
 441                         if (memcmp(result, inCRC, crcChars)==0){
 442                                 PrintAndLog("\nFound a possible match!\nModel: %s\nValue: %s\n",Models[i], result);
 443                                 //optional - stop searching if found...
 444                                 found = true;
 445                         } else {
 446                                 if (crcChars > 2){
 447                                         char *swapEndian = SwapEndianStr(result, crcChars, crcChars);
 448                                         if (memcmp(swapEndian, inCRC, crcChars)==0){
 449                                                 PrintAndLog("\nFound a possible match!\nModel: %s\nValue EndianSwapped: %s\n",Models[i], swapEndian);
 450                                                 //optional - stop searching if found...
 451                                                 found = true;
 452                                         }
 453                                         free(swapEndian);
 454                                 }
 455                         }
 456                 }
 457
 458                 //if (!found){
 459                         ans = RunModel(Models[i], outHex, true, 0, revResult);
 460                         if (ans) {
 461                                 //test for match
 462                                 if (memcmp(revResult, inCRC, crcChars)==0){
 463                                         PrintAndLog("\nFound a possible match!\nModel Reversed: %s\nValue: %s\n",Models[i], revResult);
 464                                         //optional - stop searching if found...
 465                                         found = true;
 466                                 } else {
 467                                         if (crcChars > 2){
 468                                                 char *swapEndian = SwapEndianStr(revResult, crcChars, crcChars);
 469                                                 if (memcmp(swapEndian, inCRC, crcChars)==0){
 470                                                         PrintAndLog("\nFound a possible match!\nModel Reversed: %s\nValue EndianSwapped: %s\n",Models[i], swapEndian);
 471                                                         //optional - stop searching if found...
 472                                                         found = true;
 473                                                 }
 474                                                 free(swapEndian);
 475                                         }
 476                                 }
 477                         }
 478                 //}
 479                 free(inCRC);
 480                 free(outHex);
 481                 free(Models[i]);
 482         }
 483         if (!found) PrintAndLog("\nNo matches found\n");
 484         return 1;
 485 }