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proxmark3/client/cmdlfem4x.c
Martin Holst Swende 90e278d3da Fixed several issues found using a coverity-scan
2014-10-27 21:46:04 +01:00

606 lines
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//-----------------------------------------------------------------------------
// Copyright (C) 2010 iZsh <izsh at fail0verflow.com>
//
// 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 EM4x commands
//-----------------------------------------------------------------------------
#include <stdio.h>
#include <string.h>
#include <inttypes.h>
//#include "proxusb.h"
#include "proxmark3.h"
#include "ui.h"
#include "graph.h"
#include "cmdparser.h"
#include "cmddata.h"
#include "cmdlf.h"
#include "cmdlfem4x.h"
static int CmdHelp(const char *Cmd);
/* Read the ID of an EM410x tag.
* Format:
* 1111 1111 1 <-- standard non-repeatable header
* XXXX [row parity bit] <-- 10 rows of 5 bits for our 40 bit tag ID
* ....
* CCCC <-- each bit here is parity for the 10 bits above in corresponding column
* 0 <-- stop bit, end of tag
*/
int CmdEM410xRead(const char *Cmd)
{
int i, j, clock, header, rows, bit, hithigh, hitlow, first, bit2idx, high, low;
int parity[4];
char id[11];
char id2[11];
int retested = 0;
uint8_t BitStream[MAX_GRAPH_TRACE_LEN];
high = low = 0;
/* Detect high and lows and clock */
for (i = 0; i < GraphTraceLen; i++)
{
if (GraphBuffer[i] > high)
high = GraphBuffer[i];
else if (GraphBuffer[i] < low)
low = GraphBuffer[i];
}
/* get clock */
clock = GetClock(Cmd, high, 0);
/* parity for our 4 columns */
parity[0] = parity[1] = parity[2] = parity[3] = 0;
header = rows = 0;
/* manchester demodulate */
bit = bit2idx = 0;
for (i = 0; i < (int)(GraphTraceLen / clock); i++)
{
hithigh = 0;
hitlow = 0;
first = 1;
/* Find out if we hit both high and low peaks */
for (j = 0; j < clock; j++)
{
if (GraphBuffer[(i * clock) + j] == high)
hithigh = 1;
else if (GraphBuffer[(i * clock) + j] == low)
hitlow = 1;
/* it doesn't count if it's the first part of our read
because it's really just trailing from the last sequence */
if (first && (hithigh || hitlow))
hithigh = hitlow = 0;
else
first = 0;
if (hithigh && hitlow)
break;
}
/* If we didn't hit both high and low peaks, we had a bit transition */
if (!hithigh || !hitlow)
bit ^= 1;
BitStream[bit2idx++] = bit;
}
retest:
/* We go till 5 before the graph ends because we'll get that far below */
for (i = 1; i < bit2idx - 5; i++)
{
/* Step 2: We have our header but need our tag ID */
if (header == 9 && rows < 10)
{
/* Confirm parity is correct */
if ((BitStream[i] ^ BitStream[i+1] ^ BitStream[i+2] ^ BitStream[i+3]) == BitStream[i+4])
{
/* Read another byte! */
sprintf(id+rows, "%x", (8 * BitStream[i]) + (4 * BitStream[i+1]) + (2 * BitStream[i+2]) + (1 * BitStream[i+3]));
sprintf(id2+rows, "%x", (8 * BitStream[i+3]) + (4 * BitStream[i+2]) + (2 * BitStream[i+1]) + (1 * BitStream[i]));
rows++;
/* Keep parity info */
parity[0] ^= BitStream[i];
parity[1] ^= BitStream[i+1];
parity[2] ^= BitStream[i+2];
parity[3] ^= BitStream[i+3];
/* Move 4 bits ahead */
i += 4;
}
/* Damn, something wrong! reset */
else
{
PrintAndLog("Thought we had a valid tag but failed at word %d (i=%d)", rows + 1, i);
/* Start back rows * 5 + 9 header bits, -1 to not start at same place */
i -= 9 + (5 * rows) - 5;
rows = header = 0;
}
}
/* Step 3: Got our 40 bits! confirm column parity */
else if (rows == 10)
{
/* We need to make sure our 4 bits of parity are correct and we have a stop bit */
if (BitStream[i] == parity[0] && BitStream[i+1] == parity[1] &&
BitStream[i+2] == parity[2] && BitStream[i+3] == parity[3] &&
BitStream[i+4] == 0)
{
/* Sweet! */
PrintAndLog("EM410x Tag ID: %s", id);
PrintAndLog("Unique Tag ID: %s", id2);
/* Stop any loops */
return 1;
}
/* Crap! Incorrect parity or no stop bit, start all over */
else
{
rows = header = 0;
/* Go back 59 bits (9 header bits + 10 rows at 4+1 parity) */
i -= 59;
}
}
/* Step 1: get our header */
else if (header < 9)
{
/* Need 9 consecutive 1's */
if (BitStream[i] == 1)
header++;
/* We don't have a header, not enough consecutive 1 bits */
else
header = 0;
}
}
/* if we've already retested after flipping bits, return */
if (retested++)
return 0;
/* if this didn't work, try flipping bits */
for (i = 0; i < bit2idx; i++)
BitStream[i] ^= 1;
goto retest;
}
/* emulate an EM410X tag
* Format:
* 1111 1111 1 <-- standard non-repeatable header
* XXXX [row parity bit] <-- 10 rows of 5 bits for our 40 bit tag ID
* ....
* CCCC <-- each bit here is parity for the 10 bits above in corresponding column
* 0 <-- stop bit, end of tag
*/
int CmdEM410xSim(const char *Cmd)
{
int i, n, j, h, binary[4], parity[4];
/* clock is 64 in EM410x tags */
int clock = 64;
/* clear our graph */
ClearGraph(0);
/* write it out a few times */
for (h = 0; h < 4; h++)
{
/* write 9 start bits */
for (i = 0; i < 9; i++)
AppendGraph(0, clock, 1);
/* for each hex char */
parity[0] = parity[1] = parity[2] = parity[3] = 0;
for (i = 0; i < 10; i++)
{
/* read each hex char */
sscanf(&Cmd[i], "%1x", &n);
for (j = 3; j >= 0; j--, n/= 2)
binary[j] = n % 2;
/* append each bit */
AppendGraph(0, clock, binary[0]);
AppendGraph(0, clock, binary[1]);
AppendGraph(0, clock, binary[2]);
AppendGraph(0, clock, binary[3]);
/* append parity bit */
AppendGraph(0, clock, binary[0] ^ binary[1] ^ binary[2] ^ binary[3]);
/* keep track of column parity */
parity[0] ^= binary[0];
parity[1] ^= binary[1];
parity[2] ^= binary[2];
parity[3] ^= binary[3];
}
/* parity columns */
AppendGraph(0, clock, parity[0]);
AppendGraph(0, clock, parity[1]);
AppendGraph(0, clock, parity[2]);
AppendGraph(0, clock, parity[3]);
/* stop bit */
AppendGraph(0, clock, 0);
}
/* modulate that biatch */
CmdManchesterMod("");
/* booyah! */
RepaintGraphWindow();
CmdLFSim("");
return 0;
}
/* Function is equivalent of loread + losamples + em410xread
* looped until an EM410x tag is detected */
int CmdEM410xWatch(const char *Cmd)
{
int read_h = (*Cmd == 'h');
do
{
CmdLFRead(read_h ? "h" : "");
// 2000 samples is OK for clock=64, but not clock=32. Probably want
// 8000 for clock=16. Don't want to go too high since old HID driver
// is very slow
// TBD: Auto-grow sample size based on detected sample rate. IE: If the
// rate gets lower, then grow the number of samples
// Changed by martin, 4000 x 4 = 16000,
// see http://www.proxmark.org/forum/viewtopic.php?pid=7235#p7235
CmdSamples("16000");
} while ( ! CmdEM410xRead(""));
return 0;
}
/* Read the transmitted data of an EM4x50 tag
* Format:
*
* XXXXXXXX [row parity bit (even)] <- 8 bits plus parity
* XXXXXXXX [row parity bit (even)] <- 8 bits plus parity
* XXXXXXXX [row parity bit (even)] <- 8 bits plus parity
* XXXXXXXX [row parity bit (even)] <- 8 bits plus parity
* CCCCCCCC <- column parity bits
* 0 <- stop bit
* LW <- Listen Window
*
* This pattern repeats for every block of data being transmitted.
* Transmission starts with two Listen Windows (LW - a modulated
* pattern of 320 cycles each (32/32/128/64/64)).
*
* Note that this data may or may not be the UID. It is whatever data
* is stored in the blocks defined in the control word First and Last
* Word Read values. UID is stored in block 32.
*/
int CmdEM4x50Read(const char *Cmd)
{
int i, j, startblock, skip, block, start, end, low, high;
bool complete= false;
int tmpbuff[MAX_GRAPH_TRACE_LEN / 64];
char tmp[6];
high= low= 0;
memset(tmpbuff, 0, MAX_GRAPH_TRACE_LEN / 64);
/* first get high and low values */
for (i = 0; i < GraphTraceLen; i++)
{
if (GraphBuffer[i] > high)
high = GraphBuffer[i];
else if (GraphBuffer[i] < low)
low = GraphBuffer[i];
}
/* populate a buffer with pulse lengths */
i= 0;
j= 0;
while (i < GraphTraceLen)
{
// measure from low to low
while ((GraphBuffer[i] > low) && (i<GraphTraceLen))
++i;
start= i;
while ((GraphBuffer[i] < high) && (i<GraphTraceLen))
++i;
while ((GraphBuffer[i] > low) && (i<GraphTraceLen))
++i;
if (j>=(MAX_GRAPH_TRACE_LEN/64)) {
break;
}
tmpbuff[j++]= i - start;
}
/* look for data start - should be 2 pairs of LW (pulses of 192,128) */
start= -1;
skip= 0;
for (i= 0; i < j - 4 ; ++i)
{
skip += tmpbuff[i];
if (tmpbuff[i] >= 190 && tmpbuff[i] <= 194)
if (tmpbuff[i+1] >= 126 && tmpbuff[i+1] <= 130)
if (tmpbuff[i+2] >= 190 && tmpbuff[i+2] <= 194)
if (tmpbuff[i+3] >= 126 && tmpbuff[i+3] <= 130)
{
start= i + 3;
break;
}
}
startblock= i + 3;
/* skip over the remainder of the LW */
skip += tmpbuff[i+1]+tmpbuff[i+2];
while (skip < MAX_GRAPH_TRACE_LEN && GraphBuffer[skip] > low)
++skip;
skip += 8;
/* now do it again to find the end */
end= start;
for (i += 3; i < j - 4 ; ++i)
{
end += tmpbuff[i];
if (tmpbuff[i] >= 190 && tmpbuff[i] <= 194)
if (tmpbuff[i+1] >= 126 && tmpbuff[i+1] <= 130)
if (tmpbuff[i+2] >= 190 && tmpbuff[i+2] <= 194)
if (tmpbuff[i+3] >= 126 && tmpbuff[i+3] <= 130)
{
complete= true;
break;
}
}
if (start >= 0)
PrintAndLog("Found data at sample: %i",skip);
else
{
PrintAndLog("No data found!");
PrintAndLog("Try again with more samples.");
return 0;
}
if (!complete)
{
PrintAndLog("*** Warning!");
PrintAndLog("Partial data - no end found!");
PrintAndLog("Try again with more samples.");
}
/* get rid of leading crap */
sprintf(tmp,"%i",skip);
CmdLtrim(tmp);
/* now work through remaining buffer printing out data blocks */
block= 0;
i= startblock;
while (block < 6)
{
PrintAndLog("Block %i:", block);
// mandemod routine needs to be split so we can call it for data
// just print for now for debugging
CmdManchesterDemod("i 64");
skip= 0;
/* look for LW before start of next block */
for ( ; i < j - 4 ; ++i)
{
skip += tmpbuff[i];
if (tmpbuff[i] >= 190 && tmpbuff[i] <= 194)
if (tmpbuff[i+1] >= 126 && tmpbuff[i+1] <= 130)
break;
}
while (GraphBuffer[skip] > low)
++skip;
skip += 8;
sprintf(tmp,"%i",skip);
CmdLtrim(tmp);
start += skip;
block++;
}
return 0;
}
int CmdEM410xWrite(const char *Cmd)
{
uint64_t id = 0xFFFFFFFFFFFFFFFF; // invalid id value
int card = 0xFF; // invalid card value
unsigned int clock = 0; // invalid clock value
sscanf(Cmd, "%" PRIx64 " %d %d", &id, &card, &clock);
// Check ID
if (id == 0xFFFFFFFFFFFFFFFF) {
PrintAndLog("Error! ID is required.\n");
return 0;
}
if (id >= 0x10000000000) {
PrintAndLog("Error! Given EM410x ID is longer than 40 bits.\n");
return 0;
}
// Check Card
if (card == 0xFF) {
PrintAndLog("Error! Card type required.\n");
return 0;
}
if (card < 0) {
PrintAndLog("Error! Bad card type selected.\n");
return 0;
}
// Check Clock
if (card == 1)
{
// Default: 64
if (clock == 0)
clock = 64;
// Allowed clock rates: 16, 32 and 64
if ((clock != 16) && (clock != 32) && (clock != 64)) {
PrintAndLog("Error! Clock rate %d not valid. Supported clock rates are 16, 32 and 64.\n", clock);
return 0;
}
}
else if (clock != 0)
{
PrintAndLog("Error! Clock rate is only supported on T55x7 tags.\n");
return 0;
}
if (card == 1) {
PrintAndLog("Writing %s tag with UID 0x%010" PRIx64 " (clock rate: %d)", "T55x7", id, clock);
// NOTE: We really should pass the clock in as a separate argument, but to
// provide for backwards-compatibility for older firmware, and to avoid
// having to add another argument to CMD_EM410X_WRITE_TAG, we just store
// the clock rate in bits 8-15 of the card value
card = (card & 0xFF) | (((uint64_t)clock << 8) & 0xFF00);
}
else if (card == 0)
PrintAndLog("Writing %s tag with UID 0x%010" PRIx64, "T5555", id, clock);
else {
PrintAndLog("Error! Bad card type selected.\n");
return 0;
}
UsbCommand c = {CMD_EM410X_WRITE_TAG, {card, (uint32_t)(id >> 32), (uint32_t)id}};
SendCommand(&c);
return 0;
}
int CmdReadWord(const char *Cmd)
{
int Word = 16; //default to invalid word
UsbCommand c;
sscanf(Cmd, "%d", &Word);
if (Word > 15) {
PrintAndLog("Word must be between 0 and 15");
return 1;
}
PrintAndLog("Reading word %d", Word);
c.cmd = CMD_EM4X_READ_WORD;
c.d.asBytes[0] = 0x0; //Normal mode
c.arg[0] = 0;
c.arg[1] = Word;
c.arg[2] = 0;
SendCommand(&c);
return 0;
}
int CmdReadWordPWD(const char *Cmd)
{
int Word = 16; //default to invalid word
int Password = 0xFFFFFFFF; //default to blank password
UsbCommand c;
sscanf(Cmd, "%d %x", &Word, &Password);
if (Word > 15) {
PrintAndLog("Word must be between 0 and 15");
return 1;
}
PrintAndLog("Reading word %d with password %08X", Word, Password);
c.cmd = CMD_EM4X_READ_WORD;
c.d.asBytes[0] = 0x1; //Password mode
c.arg[0] = 0;
c.arg[1] = Word;
c.arg[2] = Password;
SendCommand(&c);
return 0;
}
int CmdWriteWord(const char *Cmd)
{
int Word = 16; //default to invalid block
int Data = 0xFFFFFFFF; //default to blank data
UsbCommand c;
sscanf(Cmd, "%x %d", &Data, &Word);
if (Word > 15) {
PrintAndLog("Word must be between 0 and 15");
return 1;
}
PrintAndLog("Writting word %d with data %08X", Word, Data);
c.cmd = CMD_EM4X_WRITE_WORD;
c.d.asBytes[0] = 0x0; //Normal mode
c.arg[0] = Data;
c.arg[1] = Word;
c.arg[2] = 0;
SendCommand(&c);
return 0;
}
int CmdWriteWordPWD(const char *Cmd)
{
int Word = 8; //default to invalid word
int Data = 0xFFFFFFFF; //default to blank data
int Password = 0xFFFFFFFF; //default to blank password
UsbCommand c;
sscanf(Cmd, "%x %d %x", &Data, &Word, &Password);
if (Word > 15) {
PrintAndLog("Word must be between 0 and 15");
return 1;
}
PrintAndLog("Writting word %d with data %08X and password %08X", Word, Data, Password);
c.cmd = CMD_EM4X_WRITE_WORD;
c.d.asBytes[0] = 0x1; //Password mode
c.arg[0] = Data;
c.arg[1] = Word;
c.arg[2] = Password;
SendCommand(&c);
return 0;
}
static command_t CommandTable[] =
{
{"help", CmdHelp, 1, "This help"},
{"em410xread", CmdEM410xRead, 1, "[clock rate] -- Extract ID from EM410x tag"},
{"em410xsim", CmdEM410xSim, 0, "<UID> -- Simulate EM410x tag"},
{"em410xwatch", CmdEM410xWatch, 0, "['h'] -- Watches for EM410x 125/134 kHz tags (option 'h' for 134)"},
{"em410xwrite", CmdEM410xWrite, 1, "<UID> <'0' T5555> <'1' T55x7> [clock rate] -- Write EM410x UID to T5555(Q5) or T55x7 tag, optionally setting clock rate"},
{"em4x50read", CmdEM4x50Read, 1, "Extract data from EM4x50 tag"},
{"readword", CmdReadWord, 1, "<Word> -- Read EM4xxx word data"},
{"readwordPWD", CmdReadWordPWD, 1, "<Word> <Password> -- Read EM4xxx word data in password mode"},
{"writeword", CmdWriteWord, 1, "<Data> <Word> -- Write EM4xxx word data"},
{"writewordPWD", CmdWriteWordPWD, 1, "<Data> <Word> <Password> -- Write EM4xxx word data in password mode"},
{NULL, NULL, 0, NULL}
};
int CmdLFEM4X(const char *Cmd)
{
CmdsParse(CommandTable, Cmd);
return 0;
}
int CmdHelp(const char *Cmd)
{
CmdsHelp(CommandTable);
return 0;
}
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