// 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>
#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;
- int maxWords = MAX_ARGS;
- int wordCnt = 0;
-
- while(1){
- while(isspace(str[beginIndex])){
- ++beginIndex;
- }
- if(str[beginIndex] == '\0')
- break;
- endIndex = beginIndex;
- while (str[endIndex] && !isspace(str[endIndex])){
- ++endIndex;
- }
- int len = endIndex - beginIndex;
- char *tmp = calloc(len + 1, sizeof(char));
- memcpy(tmp, &str[beginIndex], len);
- arr[wordCnt++] = tmp;
- //PrintAndLog("cnt: %d, %s",wordCnt-1, arr[wordCnt-1]);
- beginIndex = endIndex;
- if (wordCnt == maxWords)
- break;
- }
- return wordCnt;
+ int beginIndex = 0;
+ int endIndex;
+ int maxWords = MAX_ARGS;
+ int wordCnt = 0;
+
+ while(1){
+ while(isspace(str[beginIndex])){
+ ++beginIndex;
+ }
+ if(str[beginIndex] == '\0')
+ break;
+ endIndex = beginIndex;
+ while (str[endIndex] && !isspace(str[endIndex])){
+ ++endIndex;
+ }
+ int len = endIndex - beginIndex;
+ char *tmp = calloc(len + 1, sizeof(char));
+ memcpy(tmp, &str[beginIndex], len);
+ arr[wordCnt++] = tmp;
+ //PrintAndLog("cnt: %d, %s",wordCnt-1, arr[wordCnt-1]);
+ beginIndex = endIndex;
+ if (wordCnt == maxWords)
+ break;
+ }
+ return wordCnt;
}
int CmdCrc(const char *Cmd)
return 0;
}
+int GetModels(char *Models[], int *count, uint32_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 */
+
+ //unsigned long width = 0UL;
+ //int c, mode = 0, args, psets, pass;
+ poly_t apoly, crc, qpoly = PZERO, *apolys = NULL, *pptr = NULL, *qptr = NULL;
+ model_t pset = model, *candmods, *mptr;
+ //char *string;
+
+ //myname = argv[0];
+
+ /* stdin must be binary */
+ #ifdef _WIN32
+ _setmode(STDIN_FILENO, _O_BINARY);
+ #endif /* _WIN32 */
+
+ SETBMP();
+
+ //pos=0;
+ //optind=1;
+
+ int args = 0, psets, pass;
+ int Cnt = 0;
+ if (*width == 0) { //reveng -D
+ *count = mcount();
+ //PrintAndLog("Count: %d",*count);
+ 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;
+ //PrintAndLog("Size: %d, %s",size,model.name);
+ char *tmp = calloc(size+1, sizeof(char));
+ if (tmp==NULL)
+ return uerr("out of memory?");
+
+ memcpy(tmp, model.name, size);
+ Models[mode] = tmp;
+ //ufound(&model);
+ }
+ } else { //reveng -s
+
+ if(~model.flags & P_MULXN)
+ return uerr("cannot search for non-Williams compliant models");
+
+ praloc(&model.spoly, *width);
+ praloc(&model.init, *width);
+ praloc(&model.xorout, *width);
+ if(!plen(model.spoly))
+ palloc(&model.spoly, *width);
+ else
+ *width = plen(model.spoly);
+
+ /* special case if qpoly is zero, search to end of range */
+ if(!ptst(qpoly))
+ rflags &= ~R_HAVEQ;
+
+
+ /* not going to be sending additional args
+
+ // allocate argument array
+ args = argc - optind;
+ if(!(apolys = malloc(args * sizeof(poly_t))))
+ return uerr("cannot allocate memory for argument list");
+
+ for(pptr = apolys; optind < argc; ++optind) {
+ if(uflags & C_INFILE)
+ *pptr++ = rdpoly(argv[optind], model.flags, ibperhx);
+ else
+ *pptr++ = strtop(argv[optind], model.flags, ibperhx);
+ }
+ // exit value of pptr is used hereafter!
+
+ */
+
+ /* 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();
+ //PrintAndLog("psets: %d",psets);
+ while(psets) {
+ mbynum(&pset, --psets);
+
+ /* skip if different width, or refin or refout don't match */
+ if(plen(pset.spoly) != *width || (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;
+
+ 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;
+ }
+ memcpy(tmp, pset.name, size);
+ Models[Cnt++] = tmp;
+ *count = Cnt;
+ //ufound(&pset);
+ 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);
+ }
+ if(uflags & C_RESULT) {
+ for(qptr = apolys; qptr < pptr; ++qptr)
+ pfree(qptr);
+ return 1;
+ //exit(EXIT_SUCCESS);
+ }
+ 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)) {
+ /* results were printed by the callback
+ * string = mtostr(mptr);
+ * puts(string);
+ * free(string);
+ */
+ 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");
+
+
+ }
+ //PrintAndLog("DONE");
+ return 1;
+}
+
+//test call to GetModels
+int CmdrevengTest(const char *Cmd){
+ char *Models[80];
+ int count = 0;
+ uint32_t width = 0;
+ width = param_get8(Cmd, 0);
+ //PrintAndLog("width: %d",width);
+ if (width > 89)
+ return uerr("Width cannot exceed 89");
+
+ int ans = GetModels(Models, &count, &width);
+ if (!ans) return 0;
+
+ PrintAndLog("Count: %d",count);
+ for (int i = 0; i < count; i++){
+ PrintAndLog("Model %d: %s",i,Models[i]);
+ free(Models[i]);
+ }
+ return 1;
+}
+
+//-c || -v
+int RunModel(char *inModel, char *inHexStr, bool reverse, 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;
+ unsigned long width = 0UL;
+ 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))) {
+ fprintf(stderr,"error: preset model '%s' not found. Use reveng -D to list presets.\n", inModel);
+ return 0;
+ }
+ if(c < 0)
+ return uerr("no preset models available");
+
+ // must set width so that parameter to -ipx is not zeroed
+ width = plen(model.spoly);
+ rflags |= R_HAVEP | R_HAVEI | R_HAVERI | R_HAVERO | R_HAVEX;
+
+ 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
+
+ // validate inputs
+ /* if(plen(model.spoly) == 0) {
+ * fprintf(stderr,"%s: no polynomial specified for -%c (add -w WIDTH -p POLY)\n", myname, mode);
+ * exit(EXIT_FAILURE);
+ * }
+ */
+
+ /* 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;
+}
+
+//test call to RunModel
+int CmdrevengTestC(const char *Cmd){
+ int cmdp = 0;
+ char inModel[30] = {0x00};
+ char inHexStr[30] = {0x00};
+ char result[30];
+ int dataLen;
+
+ dataLen = param_getstr(Cmd, cmdp++, inModel);
+ if (dataLen < 4) return 0;
+ dataLen = param_getstr(Cmd, cmdp++, inHexStr);
+ if (dataLen < 4) return 0;
+ bool reverse = (param_get8(Cmd, cmdp)) ? true : false;
+
+ //PrintAndLog("mod: %s, hex: %s, rev %d", inModel, inHexStr, reverse);
+ int ans = RunModel(inModel, inHexStr, reverse, result);
+ if (!ans) return 0;
+
+ PrintAndLog("Result: %s",result);
+ return 1;
+}