FIX: Coverity, strlen(Cmd) can never be lesser than zero.. *douh*

[proxmark3-svn] / client / cmdlfhitag.c

//-----------------------------------------------------------------------------
// Copyright (C) 2012 Roel Verdult
//
// 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.
//-----------------------------------------------------------------------------
// Low frequency Hitag support
//-----------------------------------------------------------------------------

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "data.h"
#include "proxmark3.h"
#include "ui.h"
#include "cmdparser.h"
#include "common.h"
#include "util.h"
#include "hitag2.h"
#include "sleep.h"
#include "cmdmain.h"

static int CmdHelp(const char *Cmd);

size_t nbytes(size_t nbits) {
	return (nbits/8)+((nbits%8)>0);
}

int CmdLFHitagList(const char *Cmd)
{
 	uint8_t *got = malloc(USB_CMD_DATA_SIZE);

	// Query for the actual size of the trace
	UsbCommand response;
	GetFromBigBuf(got, USB_CMD_DATA_SIZE, 0);
	WaitForResponse(CMD_ACK, &response);
	uint16_t traceLen = response.arg[2];
	if (traceLen > USB_CMD_DATA_SIZE) {
		uint8_t *p = realloc(got, traceLen);
		if (p == NULL) {
			PrintAndLog("Cannot allocate memory for trace");
			free(got);
			return 2;
		}
		got = p;
		GetFromBigBuf(got, traceLen, 0);
		WaitForResponse(CMD_ACK,NULL);
	}
	
	PrintAndLog("recorded activity (TraceLen = %d bytes):");
	PrintAndLog(" ETU     :nbits: who bytes");
	PrintAndLog("---------+-----+----+-----------");

	int i = 0;
	int prev = -1;
	int len = strlen(Cmd);

	char filename[FILE_PATH_SIZE]  = { 0x00 };
	FILE* pf = NULL;
  	
	if (len > FILE_PATH_SIZE) len = FILE_PATH_SIZE;
	memcpy(filename, Cmd, len);
   
	if (strlen(filename) > 0) {
		if ((pf = fopen(filename,"wb")) == NULL) {
			PrintAndLog("Error: Could not open file [%s]",filename);
			return 1;
		}
	}

	for (;;) {
  
		if(i >= traceLen) { break; }

		bool isResponse;
		int timestamp = *((uint32_t *)(got+i));
		if (timestamp & 0x80000000) {
			timestamp &= 0x7fffffff;
			isResponse = 1;
		} else {
			isResponse = 0;
		}

		int parityBits = *((uint32_t *)(got+i+4));
		// 4 bytes of additional information...
		// maximum of 32 additional parity bit information
		//
		// TODO:
		// at each quarter bit period we can send power level (16 levels)
		// or each half bit period in 256 levels.

		int bits = got[i+8];
		int len = nbytes(got[i+8]);

		if (len > 100) {
		  break;
		}
		if (i + len > traceLen) { break;}

		uint8_t *frame = (got+i+9);

		// Break and stick with current result if buffer was not completely full
		if (frame[0] == 0x44 && frame[1] == 0x44 && frame[3] == 0x44) { break; }

		char line[1000] = "";
		int j;
		for (j = 0; j < len; j++) {
		  int oddparity = 0x01;
		  int k;

		  for (k=0;k<8;k++) {
			oddparity ^= (((frame[j] & 0xFF) >> k) & 0x01);
		  }

		  //if((parityBits >> (len - j - 1)) & 0x01) {
		  if (isResponse && (oddparity != ((parityBits >> (len - j - 1)) & 0x01))) {
			sprintf(line+(j*4), "%02x!  ", frame[j]);
		  }
		  else {
			sprintf(line+(j*4), "%02x   ", frame[j]);
		  }
		}

		PrintAndLog(" +%7d:  %3d: %s %s",
			(prev < 0 ? 0 : (timestamp - prev)),
			bits,
			(isResponse ? "TAG" : "   "),
			line);

		if (pf) {
			fprintf(pf," +%7d:  %3d: %s %s\n",
				(prev < 0 ? 0 : (timestamp - prev)),
				bits,
				(isResponse ? "TAG" : "   "),
				line);
		}
		
		prev = timestamp;
		i += (len + 9);
	}
  
	if (pf) {
		fclose(pf);
		PrintAndLog("Recorded activity succesfully written to file: %s", filename);
	}

	free(got);
	return 0;
}

int CmdLFHitagSnoop(const char *Cmd) {
	UsbCommand c = {CMD_SNOOP_HITAG};
	clearCommandBuffer();
	SendCommand(&c);
	return 0;
}

int CmdLFHitagSim(const char *Cmd) {
    
	UsbCommand c = {CMD_SIMULATE_HITAG};
	char filename[FILE_PATH_SIZE] = { 0x00 };
	FILE* pf;
	bool tag_mem_supplied;
	
	int len = strlen(Cmd);
	if (len > FILE_PATH_SIZE) len = FILE_PATH_SIZE;
	memcpy(filename, Cmd, len);

	if (strlen(filename) > 0) {
		if ((pf = fopen(filename,"rb+")) == NULL) {
			PrintAndLog("Error: Could not open file [%s]",filename);
			return 1;
		}
		tag_mem_supplied = true;
		if (fread(c.d.asBytes,48,1,pf) == 0) {
			PrintAndLog("Error: File reading error");
			fclose(pf);
			return 1;
		}
		fclose(pf);
	} else {
		tag_mem_supplied = false;
	}

	// Does the tag comes with memory
	c.arg[0] = (uint32_t)tag_mem_supplied;

	clearCommandBuffer();
	SendCommand(&c);
	return 0;
}

int CmdLFHitagReader(const char *Cmd) {
	

	UsbCommand c = {CMD_READER_HITAG};//, {param_get32ex(Cmd,0,0,10),param_get32ex(Cmd,1,0,16),param_get32ex(Cmd,2,0,16),param_get32ex(Cmd,3,0,16)}};
	hitag_data* htd = (hitag_data*)c.d.asBytes;
	hitag_function htf = param_get32ex(Cmd,0,0,10);
	
	switch (htf) {
		case RHT2F_PASSWORD: {
			num_to_bytes(param_get32ex(Cmd,1,0,16),4,htd->pwd.password);
		} break;
		case RHT2F_AUTHENTICATE: {
			num_to_bytes(param_get32ex(Cmd,1,0,16),4,htd->auth.NrAr);
			num_to_bytes(param_get32ex(Cmd,2,0,16),4,htd->auth.NrAr+4);
		} break;
		case RHT2F_CRYPTO: {
			num_to_bytes(param_get64ex(Cmd,1,0,16),6,htd->crypto.key);
		} break;
		case RHT2F_TEST_AUTH_ATTEMPTS: {
			// No additional parameters needed
		} break;
		default: {
			PrintAndLog("Error: unkown reader function %d",htf);
			PrintAndLog("Hitag reader functions");
			PrintAndLog(" HitagS (0*)");
			PrintAndLog(" Hitag1 (1*)");
			PrintAndLog(" Hitag2 (2*)");
			PrintAndLog("  21 <password> (password mode)");
			PrintAndLog("  22 <nr> <ar> (authentication)");
			PrintAndLog("  23 <key> (authentication) key is in format: ISK high + ISK low");
			PrintAndLog("  25 (test recorded authentications)");
			return 1;
		} break;
	}

	// Copy the hitag2 function into the first argument
	c.arg[0] = htf;

	clearCommandBuffer();
	// Send the command to the proxmark
	SendCommand(&c);

	UsbCommand resp;
	WaitForResponse(CMD_ACK,&resp);

	// Check the return status, stored in the first argument
	if (resp.arg[0] == false) return 1;

	uint32_t id = bytes_to_num(resp.d.asBytes,4);
	char filename[FILE_PATH_SIZE];
	FILE* pf = NULL;

	sprintf(filename,"%08x_%04x.ht2",id,(rand() & 0xffff));
	if ((pf = fopen(filename,"wb")) == NULL) {
		PrintAndLog("Error: Could not open file [%s]",filename);
		return 1;
	}

	// Write the 48 tag memory bytes to file and finalize
	fwrite(resp.d.asBytes,1,48,pf);
	fclose(pf);

	PrintAndLog("Succesfully saved tag memory to [%s]",filename);
	return 0;
}

static command_t CommandTable[] = {
	{"help",    CmdHelp,           1, "This help"},
	{"list",    CmdLFHitagList,    1, "<outfile> List Hitag trace history"},
	{"reader",  CmdLFHitagReader,  1, "Act like a Hitag Reader"},
	{"sim",     CmdLFHitagSim,     1, "<infile> Simulate Hitag transponder"},
	{"snoop",   CmdLFHitagSnoop,   1, "Eavesdrop Hitag communication"},
	{NULL, NULL, 0, NULL}
};

int CmdLFHitag(const char *Cmd)
{
	CmdsParse(CommandTable, Cmd);
	return 0;
}

int CmdHelp(const char *Cmd)
{
	CmdsHelp(CommandTable);
	return 0;
}