// CRC Calculations from the software reveng commands
//-----------------------------------------------------------------------------
+#include <stdlib.h>
+#ifdef _WIN32
+# include <io.h>
+# include <fcntl.h>
+# ifndef STDIN_FILENO
+# define STDIN_FILENO 0
+# endif /* STDIN_FILENO */
+#endif /* _WIN32 */
+
#include <stdio.h>
#include <string.h>
-//#include <stdlib.h>
-//#include <ctype.h>
#include "cmdmain.h"
#include "cmdcrc.h"
#include "reveng/reveng.h"
#define MAX_ARGS 20
+int uerr(char *msg){
+ PrintAndLog("%s",msg);
+ return 0;
+}
+
int split(char *str, char *arr[MAX_ARGS]){
int beginIndex = 0;
int endIndex;
memcpy(Cmd2 + 7, Cmd, 50);
char *argv[MAX_ARGS];
int argc = split(Cmd2, argv);
- //PrintAndLog("argc: %d, %s %s Cmd: %s",argc, argv[0], Cmd2, Cmd);
- reveng_main(argc, argv);
- for(int i = 0; i < argc; ++i){
- //puts(arr[i]);
+
+ if (argc == 3 && memcmp(argv[1],"-g",2)==0) {
+ CmdrevengSearch(argv[2]);
+ } else {
+ reveng_main(argc, argv);
+ }
+ //PrintAndLog("DEBUG argc: %d, %s %s Cmd: %s",argc, argv[0], Cmd2, Cmd);
+ for(int i = 0; i < argc; ++i) {
free(argv[i]);
}
return 0;
}
+//returns array of model names and the count of models returning
+// as well as a width array for the width of each model
+int GetModels(char *Models[], int *count, uint8_t *width){
+ /* default values */
+ static model_t model = {
+ PZERO, /* no CRC polynomial, user must specify */
+ PZERO, /* Init = 0 */
+ P_BE, /* RefIn = false, RefOut = false, plus P_RTJUST setting in reveng.h */
+ PZERO, /* XorOut = 0 */
+ PZERO, /* check value unused */
+ NULL /* no model name */
+ };
+
+ int ibperhx = 8;//, obperhx = 8;
+ int rflags = 0, uflags = 0; /* search and UI flags */
+ poly_t apoly, crc, qpoly = PZERO, *apolys = NULL, *pptr = NULL, *qptr = NULL;
+ model_t pset = model, *candmods, *mptr;
+
+ /* stdin must be binary */
+ #ifdef _WIN32
+ _setmode(STDIN_FILENO, _O_BINARY);
+ #endif /* _WIN32 */
+
+ SETBMP();
+
+ int args = 0, psets, pass;
+ int Cnt = 0;
+ if (width[0] == 0) { //reveng -D
+ *count = mcount();
+ if(!*count)
+ return uerr("no preset models available");
+
+ for(int mode = 0; mode < *count; ++mode) {
+ mbynum(&model, mode);
+ mcanon(&model);
+ size_t size = (model.name && *model.name) ? strlen(model.name) : 6;
+ char *tmp = calloc(size+1, sizeof(char));
+ if (tmp==NULL)
+ return uerr("out of memory?");
+
+ memcpy(tmp, model.name, size);
+ Models[mode] = tmp;
+ width[mode] = plen(model.spoly);
+ }
+ mfree(&model);
+ } else { //reveng -s
+
+ if(~model.flags & P_MULXN)
+ return uerr("cannot search for non-Williams compliant models");
+
+ praloc(&model.spoly, (unsigned long)width[0]);
+ praloc(&model.init, (unsigned long)width[0]);
+ praloc(&model.xorout, (unsigned long)width[0]);
+
+ if(!plen(model.spoly))
+ palloc(&model.spoly, (unsigned long)width[0]);
+ else
+ width[0] = (uint8_t)plen(model.spoly);
+
+ /* special case if qpoly is zero, search to end of range */
+ if(!ptst(qpoly))
+ rflags &= ~R_HAVEQ;
+
+ /* if endianness not specified, try
+ * little-endian then big-endian.
+ * NB: crossed-endian algorithms will not be
+ * searched.
+ */
+ /* scan against preset models */
+ if(~uflags & C_FORCE) {
+ pass = 0;
+ Cnt = 0;
+ do {
+ psets = mcount();
+
+ while(psets) {
+ mbynum(&pset, --psets);
+
+ /* skip if different width, or refin or refout don't match */
+ if(plen(pset.spoly) != width[0] || (model.flags ^ pset.flags) & (P_REFIN | P_REFOUT))
+ continue;
+ /* skip if the preset doesn't match specified parameters */
+ if(rflags & R_HAVEP && pcmp(&model.spoly, &pset.spoly))
+ continue;
+ if(rflags & R_HAVEI && psncmp(&model.init, &pset.init))
+ continue;
+ if(rflags & R_HAVEX && psncmp(&model.xorout, &pset.xorout))
+ continue;
+
+ //for additional args (not used yet, maybe future?)
+ apoly = pclone(pset.xorout);
+ if(pset.flags & P_REFOUT)
+ prev(&apoly);
+
+ for(qptr = apolys; qptr < pptr; ++qptr) {
+ crc = pcrc(*qptr, pset.spoly, pset.init, apoly, 0);
+ if(ptst(crc)) {
+ pfree(&crc);
+ break;
+ } else
+ pfree(&crc);
+ }
+ pfree(&apoly);
+ if(qptr == pptr) {
+
+ /* the selected model solved all arguments */
+
+ mcanon(&pset);
+
+ size_t size = (pset.name && *pset.name) ? strlen(pset.name) : 6;
+ //PrintAndLog("Size: %d, %s, count: %d",size,pset.name, Cnt);
+ char *tmp = calloc(size+1, sizeof(char));
+ if (tmp == NULL){
+ PrintAndLog("out of memory?");
+ return 0;
+ }
+ width[Cnt] = width[0];
+ memcpy(tmp, pset.name, size);
+ Models[Cnt++] = tmp;
+ *count = Cnt;
+ uflags |= C_RESULT;
+ }
+ }
+ mfree(&pset);
+
+ /* toggle refIn/refOut and reflect arguments */
+ if(~rflags & R_HAVERI) {
+ model.flags ^= P_REFIN | P_REFOUT;
+ for(qptr = apolys; qptr < pptr; ++qptr)
+ prevch(qptr, ibperhx);
+ }
+ } while(~rflags & R_HAVERI && ++pass < 2);
+ }
+ //got everything now free the memory...
+
+ if(uflags & C_RESULT) {
+ for(qptr = apolys; qptr < pptr; ++qptr)
+ pfree(qptr);
+ }
+ if(!(model.flags & P_REFIN) != !(model.flags & P_REFOUT))
+ return uerr("cannot search for crossed-endian models");
+
+ pass = 0;
+ do {
+ mptr = candmods = reveng(&model, qpoly, rflags, args, apolys);
+ if(mptr && plen(mptr->spoly))
+ uflags |= C_RESULT;
+ while(mptr && plen(mptr->spoly)) {
+ mfree(mptr++);
+ }
+ free(candmods);
+ if(~rflags & R_HAVERI) {
+ model.flags ^= P_REFIN | P_REFOUT;
+ for(qptr = apolys; qptr < pptr; ++qptr)
+ prevch(qptr, ibperhx);
+ }
+ } while(~rflags & R_HAVERI && ++pass < 2);
+ for(qptr = apolys; qptr < pptr; ++qptr)
+ pfree(qptr);
+ free(apolys);
+ if(~uflags & C_RESULT)
+ return uerr("no models found");
+ mfree(&model);
+
+ }
+ return 1;
+}
+
+//-c || -v
+//inModel = valid model name string - CRC-8
+//inHexStr = input hex string to calculate crc on
+//reverse = reverse calc option if true
+//endian = {0 = calc default endian input and output, b = big endian input and output, B = big endian output, r = right justified
+// l = little endian input and output, L = little endian output only, t = left justified}
+//result = calculated crc hex string
+int RunModel(char *inModel, char *inHexStr, bool reverse, char endian, char *result){
+ /* default values */
+ static model_t model = {
+ PZERO, // no CRC polynomial, user must specify
+ PZERO, // Init = 0
+ P_BE, // RefIn = false, RefOut = false, plus P_RTJUST setting in reveng.h
+ PZERO, // XorOut = 0
+ PZERO, // check value unused
+ NULL // no model name
+ };
+ int ibperhx = 8, obperhx = 8;
+ int rflags = 0; // search flags
+ int c;
+ poly_t apoly, crc;
+
+ char *string;
+
+ // stdin must be binary
+ #ifdef _WIN32
+ _setmode(STDIN_FILENO, _O_BINARY);
+ #endif /* _WIN32 */
+
+ SETBMP();
+ //set model
+ if(!(c = mbynam(&model, inModel))) {
+ PrintAndLog("error: preset model '%s' not found. Use reveng -D to list presets.", inModel);
+ return 0;
+ }
+ if(c < 0)
+ return uerr("no preset models available");
+
+ rflags |= R_HAVEP | R_HAVEI | R_HAVERI | R_HAVERO | R_HAVEX;
+
+ //set flags
+ switch (endian) {
+ case 'b': /* b big-endian (RefIn = false, RefOut = false ) */
+ model.flags &= ~P_REFIN;
+ rflags |= R_HAVERI;
+ /* fall through: */
+ case 'B': /* B big-endian output (RefOut = false) */
+ model.flags &= ~P_REFOUT;
+ rflags |= R_HAVERO;
+ mnovel(&model);
+ /* fall through: */
+ case 'r': /* r right-justified */
+ model.flags |= P_RTJUST;
+ break;
+ case 'l': /* l little-endian input and output */
+ model.flags |= P_REFIN;
+ rflags |= R_HAVERI;
+ /* fall through: */
+ case 'L': /* L little-endian output */
+ model.flags |= P_REFOUT;
+ rflags |= R_HAVERO;
+ mnovel(&model);
+ /* fall through: */
+ case 't': /* t left-justified */
+ model.flags &= ~P_RTJUST;
+ break;
+ }
+ /* canonicalise the model, so the one we dump is the one we
+ * calculate with (not with -s, spoly may be blank which will
+ * normalise to zero and clear init and xorout.)
+ */
+ mcanon(&model);
+
+
+ if (reverse) {
+ // v calculate reversed CRC
+ /* Distinct from the -V switch as this causes
+ * the arguments and output to be reversed as well.
+ */
+ // reciprocate Poly
+ prcp(&model.spoly);
+
+ /* mrev() does:
+ * if(refout) prev(init); else prev(xorout);
+ * but here the entire argument polynomial is
+ * reflected, not just the characters, so RefIn
+ * and RefOut are not inverted as with -V.
+ * Consequently Init is the mirror image of the
+ * one resulting from -V, and so we have:
+ */
+ if(~model.flags & P_REFOUT) {
+ prev(&model.init);
+ prev(&model.xorout);
+ }
+
+ // swap init and xorout
+ apoly = model.init;
+ model.init = model.xorout;
+ model.xorout = apoly;
+ }
+ // c calculate CRC
+
+ /* in the Williams model, xorout is applied after the refout stage.
+ * as refout is part of ptostr(), we reverse xorout here.
+ */
+ if(model.flags & P_REFOUT)
+ prev(&model.xorout);
+
+ apoly = strtop(inHexStr, model.flags, ibperhx);
+
+ if(reverse)
+ prev(&apoly);
+
+ crc = pcrc(apoly, model.spoly, model.init, model.xorout, model.flags);
+
+ if(reverse)
+ prev(&crc);
+
+ string = ptostr(crc, model.flags, obperhx);
+ for (int i = 0; i < 50; i++){
+ result[i] = string[i];
+ if (result[i]==0) break;
+ }
+ free(string);
+ pfree(&crc);
+ pfree(&apoly);
+ return 1;
+}
+//returns a calloced string (needs to be freed)
+char *SwapEndianStr(const char *inStr, const size_t len, const uint8_t blockSize){
+ char *tmp = calloc(len+1, sizeof(char));
+ for (uint8_t block=0; block < (uint8_t)(len/blockSize); block++){
+ for (size_t i = 0; i < blockSize; i+=2){
+ tmp[i+(blockSize*block)] = inStr[(blockSize-1-i-1)+(blockSize*block)];
+ tmp[i+(blockSize*block)+1] = inStr[(blockSize-1-i)+(blockSize*block)];
+ }
+ }
+ return tmp;
+}
+
+// takes hex string in and searches for a matching result (hex string must include checksum)
+int CmdrevengSearch(const char *Cmd){
+ char inHexStr[50] = {0x00};
+ int dataLen = param_getstr(Cmd, 0, inHexStr);
+ if (dataLen < 4) return 0;
+
+ char *Models[80];
+ int count = 0;
+ uint8_t width[80];
+ width[0] = 0;
+ uint8_t crcChars = 0;
+ char result[30];
+ char revResult[30];
+ int ans = GetModels(Models, &count, width);
+ bool found = false;
+ if (!ans) return 0;
+
+ // try each model and get result
+ for (int i = 0; i < count; i++){
+ /*if (found) {
+ free(Models[i]);
+ continue;
+ }*/
+ // round up to # of characters in this model's crc
+ crcChars = ((width[i]+7)/8)*2;
+ // can't test a model that has more crc digits than our data
+ if (crcChars >= dataLen)
+ continue;
+ memset(result, 0, 30);
+ char *inCRC = calloc(crcChars+1, sizeof(char));
+ memcpy(inCRC, inHexStr+(dataLen-crcChars), crcChars);
+
+ char *outHex = calloc(dataLen-crcChars+1, sizeof(char));
+ memcpy(outHex, inHexStr, dataLen-crcChars);
+
+ //PrintAndLog("DEBUG: dataLen: %d, crcChars: %d, Model: %s, CRC: %s, width: %d, outHex: %s",dataLen, crcChars, Models[i], inCRC, width[i], outHex);
+ ans = RunModel(Models[i], outHex, false, 0, result);
+ if (ans) {
+ //test for match
+ if (memcmp(result, inCRC, crcChars)==0){
+ PrintAndLog("\nFound a possible match!\nModel: %s\nValue: %s\n",Models[i], result);
+ //optional - stop searching if found...
+ found = true;
+ } else {
+ if (crcChars > 2){
+ char *swapEndian = SwapEndianStr(result, crcChars, crcChars);
+ if (memcmp(swapEndian, inCRC, crcChars)==0){
+ PrintAndLog("\nFound a possible match!\nModel: %s\nValue EndianSwapped: %s\n",Models[i], swapEndian);
+ //optional - stop searching if found...
+ found = true;
+ }
+ free(swapEndian);
+ }
+ }
+ }
+
+ //if (!found){
+ ans = RunModel(Models[i], outHex, true, 0, revResult);
+ if (ans) {
+ //test for match
+ if (memcmp(revResult, inCRC, crcChars)==0){
+ PrintAndLog("\nFound a possible match!\nModel Reversed: %s\nValue: %s\n",Models[i], revResult);
+ //optional - stop searching if found...
+ found = true;
+ } else {
+ if (crcChars > 2){
+ char *swapEndian = SwapEndianStr(revResult, crcChars, crcChars);
+ if (memcmp(swapEndian, inCRC, crcChars)==0){
+ PrintAndLog("\nFound a possible match!\nModel Reversed: %s\nValue EndianSwapped: %s\n",Models[i], swapEndian);
+ //optional - stop searching if found...
+ found = true;
+ }
+ free(swapEndian);
+ }
+ }
+ }
+ //}
+ free(inCRC);
+ free(outHex);
+ free(Models[i]);
+ }
+ if (!found) PrintAndLog("\nNo matches found\n");
+ return 1;
+}
projects / proxmark3-svn / blobdiff