[proxmark3-svn] / client / cmdcrc.c

//-----------------------------------------------------------------------------
// Copyright (C) 2015 iceman <iceman at iuse.se>
//
// This code is licensed to you under the terms of the GNU GPL, version 2 or,
// at your option, any later version. See the LICENSE.txt file for the text of
// the license.
//-----------------------------------------------------------------------------
// 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 "cmdmain.h"
#include "cmdcrc.h"
#include "reveng/reveng.h"
#include "ui.h"
#include "util.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 CmdCrc(const char *Cmd)
{
	char name[] = {"reveng "};
	char Cmd2[50 + 7];
	memcpy(Cmd2, name, 7);
	memcpy(Cmd2 + 7, Cmd, 50);
	char *argv[MAX_ARGS];
	int argc = split(Cmd2, argv);

	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;
						}
						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;
}
Commit	Line	Data
9962091e	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
60e86577	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
9962091e	20	#include <stdio.h>
9962091e	21	#include <string.h>
a71ece51	22	#include "cmdmain.h"
9962091e	23	#include "cmdcrc.h"
a71ece51	24	#include "reveng/reveng.h"
	25	#include "ui.h"
	26	#include "util.h"
9962091e	27
a71ece51	28	#define MAX_ARGS 20
9962091e	29
60e86577	30	int uerr(char *msg){
	31	PrintAndLog("%s",msg);
	32	return 0;
	33	}
	34
a71ece51	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){
9c624f67	42	while(isspace(str[beginIndex])) {
a71ece51	43	++beginIndex;
a71ece51	44	}
9c624f67	45	if(str[beginIndex] == '\0') {
a71ece51	46	break;
9c624f67	47	}
a71ece51	48	endIndex = beginIndex;
9c624f67	49	while (str[endIndex] && !isspace(str[endIndex])) {
a71ece51	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	}
9962091e	63
	64	int CmdCrc(const char *Cmd)
	65	{
a71ece51	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);
99789601	72
	73	if (argc == 3 && memcmp(argv[1],"-g",2)==0) {
	74	CmdrevengSearch(argv[2]);
	75	} else {
13629a71	76	reveng_main(argc, argv);
99789601	77	}
99789601	78	//PrintAndLog("DEBUG argc: %d, %s %s Cmd: %s",argc, argv[0], Cmd2, Cmd);
13629a71	79	for(int i = 0; i < argc; ++i) {
a71ece51	80	free(argv[i]);
	81	}
	82
9962091e	83	return 0;
	84	}
	85
99789601	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){
60e86577	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	};
dd1df490	98
60e86577	99	int ibperhx = 8;//, obperhx = 8;
60e86577	100	int rflags = 0, uflags = 0; /* search and UI flags */
60e86577	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;
99789601	113	if (width[0] == 0) { //reveng -D
60e86577	114	*count = mcount();
60e86577	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;
60e86577	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;
99789601	128	width[mode] = plen(model.spoly);
60e86577	129	}
dd1df490	130	mfree(&model);
60e86577	131	} else { //reveng -s
60e86577	132
13629a71	133	if(~model.flags & P_MULXN)
13629a71	134	return uerr("cannot search for non-Williams compliant models");
60e86577	135
99789601	136	praloc(&model.spoly, (unsigned long)width[0]);
	137	praloc(&model.init, (unsigned long)width[0]);
	138	praloc(&model.xorout, (unsigned long)width[0]);
13629a71	139
13629a71	140	if(!plen(model.spoly))
99789601	141	palloc(&model.spoly, (unsigned long)width[0]);
13629a71	142	else
99789601	143	width[0] = (uint8_t)plen(model.spoly);
60e86577	144
13629a71	145	/* special case if qpoly is zero, search to end of range */
	146	if(!ptst(qpoly))
	147	rflags &= ~R_HAVEQ;
60e86577	148
13629a71	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 */
9c624f67	155	if (~uflags & C_FORCE) {
13629a71	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 */
9c624f67	165	if( plen(pset.spoly) != width[0] \|\| (model.flags ^ pset.flags) & (P_REFIN \| P_REFOUT))
13629a71	166	continue;
13629a71	167	/* skip if the preset doesn't match specified parameters */
9c624f67	168	if (rflags & R_HAVEP && pcmp(&model.spoly, &pset.spoly))
13629a71	169	continue;
9c624f67	170	if (rflags & R_HAVEI && psncmp(&model.init, &pset.init))
13629a71	171	continue;
9c624f67	172	if (rflags & R_HAVEX && psncmp(&model.xorout, &pset.xorout))
13629a71	173	continue;
13629a71	174
9c624f67	175	//for additional args (not used yet, maybe future?)
13629a71	176	apoly = pclone(pset.xorout);
9c624f67	177
9c624f67	178	if (pset.flags & P_REFOUT)
13629a71	179	prev(&apoly);
9c624f67	180
	181
	182	for (qptr = apolys; qptr < pptr; ++qptr) {
13629a71	183	crc = pcrc(*qptr, pset.spoly, pset.init, apoly, 0);
9c624f67	184	if (ptst(crc)) {
13629a71	185	pfree(&crc);
13629a71	186	break;
9c624f67	187	}
9c624f67	188	pfree(&crc);
60e86577	189	}
13629a71	190	pfree(&apoly);
9c624f67	191
9c624f67	192	if (qptr == pptr) {
99789601	193
13629a71	194	/* the selected model solved all arguments */
13629a71	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	}
9c624f67	204	width[Cnt] = width[0];
13629a71	205	memcpy(tmp, pset.name, size);
	206	Models[Cnt++] = tmp;
	207	*count = Cnt;
	208	uflags \|= C_RESULT;
	209	}
60e86577	210	}
13629a71	211	mfree(&pset);
	212
	213	/* toggle refIn/refOut and reflect arguments */
9c624f67	214	if (~rflags & R_HAVERI) {
60e86577	215	model.flags ^= P_REFIN \| P_REFOUT;
9c624f67	216	for (qptr = apolys; qptr < pptr; ++qptr) {
60e86577	217	prevch(qptr, ibperhx);
9c624f67	218	}
60e86577	219	}
9c624f67	220	} while (~rflags & R_HAVERI && ++pass < 2);
13629a71	221	}
	222	//got everything now free the memory...
	223
9c624f67	224	if (uflags & C_RESULT) {
9c624f67	225	for (qptr = apolys; qptr < pptr; ++qptr) {
60e86577	226	pfree(qptr);
9c624f67	227	}
13629a71	228	}
9c624f67	229	if (!(model.flags & P_REFIN) != !(model.flags & P_REFOUT))
13629a71	230	return uerr("cannot search for crossed-endian models");
	231
	232	pass = 0;
	233	do {
	234	mptr = candmods = reveng(&model, qpoly, rflags, args, apolys);
9c624f67	235	if (mptr && plen(mptr->spoly)) {
13629a71	236	uflags \|= C_RESULT;
9c624f67	237	}
9c624f67	238	while (mptr && plen(mptr->spoly)) {
13629a71	239	mfree(mptr++);
	240	}
	241	free(candmods);
9c624f67	242	if (~rflags & R_HAVERI) {
13629a71	243	model.flags ^= P_REFIN \| P_REFOUT;
9c624f67	244	for (qptr = apolys; qptr < pptr; ++qptr) {
13629a71	245	prevch(qptr, ibperhx);
9c624f67	246	}
13629a71	247	}
9c624f67	248	} while (~rflags & R_HAVERI && ++pass < 2);
	249
	250	for (qptr = apolys; qptr < pptr; ++qptr) {
13629a71	251	pfree(qptr);
9c624f67	252	}
13629a71	253	free(apolys);
9c624f67	254	if (~uflags & C_RESULT)
13629a71	255	return uerr("no models found");
9c624f67	256
13629a71	257	mfree(&model);
60e86577	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;
60e86577	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
9c624f67	293	if (!(c = mbynam(&model, inModel))) {
dd1df490	294	PrintAndLog("error: preset model '%s' not found. Use reveng -D to list presets.", inModel);
60e86577	295	return 0;
60e86577	296	}
9c624f67	297	if (c < 0)
60e86577	298	return uerr("no preset models available");
60e86577	299
60e86577	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	}
13629a71	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	*/
60e86577	333	mcanon(&model);
60e86577	334
13629a71	335
60e86577	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	*/
9c624f67	352	if (~model.flags & P_REFOUT) {
60e86577	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	*/
9c624f67	367	if (model.flags & P_REFOUT)
60e86577	368	prev(&model.xorout);
	369
	370	apoly = strtop(inHexStr, model.flags, ibperhx);
	371
9c624f67	372	if (reverse)
60e86577	373	prev(&apoly);
	374
	375	crc = pcrc(apoly, model.spoly, model.init, model.xorout, model.flags);
	376
9c624f67	377	if (reverse)
60e86577	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	}
99789601	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+(blockSizeblock)] = inStr[(blockSize-1-i-1)+(blockSizeblock)];
	396	tmp[i+(blockSizeblock)+1] = inStr[(blockSize-1-i)+(blockSizeblock)];
	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){
1417a7f9	442	PrintAndLog("\nFound a possible match!\nModel: %s\nValue: %s\n",Models[i], result);
99789601	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){
1417a7f9	449	PrintAndLog("\nFound a possible match!\nModel: %s\nValue EndianSwapped: %s\n",Models[i], swapEndian);
99789601	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){
1417a7f9	463	PrintAndLog("\nFound a possible match!\nModel Reversed: %s\nValue: %s\n",Models[i], revResult);
99789601	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){
1417a7f9	470	PrintAndLog("\nFound a possible match!\nModel Reversed: %s\nValue EndianSwapped: %s\n",Models[i], swapEndian);
99789601	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;
1417a7f9	485	}