Added command to read PCF7931 125Khz LF tags. This is a beta version which needs to be tested.

This commit is contained in:
chalk.secu@gmail.com 2013-01-18 21:31:35 +00:00
parent e98300f245
commit f5fca2ed62
8 changed files with 338 additions and 1 deletions

View file

@ -666,6 +666,10 @@ void UsbPacketReceived(uint8_t *packet, int len)
case CMD_T55XX_READ_TRACE: // Clone HID tag by ID to T55x7
T55xxReadTrace();
break;
case CMD_PCF7931_READ: // Read PCF7931 tag
ReadPCF7931();
UsbSendPacket((uint8_t*)&ack, sizeof(ack));
break;
#endif
#ifdef WITH_HITAG

View file

@ -124,6 +124,10 @@ void CopyIndala224toT55x7(int uid1, int uid2, int uid3, int uid4, int uid5, int
void T55xxWriteBlock(uint32_t Data, uint32_t Block, uint32_t Pwd, uint8_t PwdMode);
void T55xxReadBlock(uint32_t Block, uint32_t Pwd, uint8_t PwdMode );
void T55xxReadTrace(void);
int DemodPCF7931(uint8_t **outBlocks);
int IsBlock0PCF7931(uint8_t *Block);
int IsBlock1PCF7931(uint8_t *Block);
void ReadPCF7931();
/// iso14443.h
void SimulateIso14443Tag(void);

View file

@ -1295,3 +1295,261 @@ void CopyIndala224toT55x7(int uid1, int uid2, int uid3, int uid4, int uid5, int
DbpString("DONE!");
}
#define abs(x) ( ((x)<0) ? -(x) : (x) )
#define max(x,y) ( x<y ? y:x)
int DemodPCF7931(uint8_t **outBlocks) {
uint8_t BitStream[256];
uint8_t Blocks[8][16];
uint8_t *GraphBuffer = (uint8_t *)BigBuf;
int GraphTraceLen = sizeof(BigBuf);
int i, j, lastval, bitidx, half_switch;
int clock = 64;
int tolerance = clock / 8;
int pmc, block_done;
int lc, warnings = 0;
int num_blocks = 0;
int lmin=128, lmax=128;
uint8_t dir;
AcquireRawAdcSamples125k(0);
lmin = 64;
lmax = 192;
i = 2;
/* Find first local max/min */
if(GraphBuffer[1] > GraphBuffer[0]) {
while(i < GraphTraceLen) {
if( !(GraphBuffer[i] > GraphBuffer[i-1]) && GraphBuffer[i] > lmax)
break;
i++;
}
dir = 0;
}
else {
while(i < GraphTraceLen) {
if( !(GraphBuffer[i] < GraphBuffer[i-1]) && GraphBuffer[i] < lmin)
break;
i++;
}
dir = 1;
}
lastval = i++;
half_switch = 0;
pmc = 0;
block_done = 0;
for (bitidx = 0; i < GraphTraceLen; i++)
{
if ( (GraphBuffer[i-1] > GraphBuffer[i] && dir == 1 && GraphBuffer[i] > lmax) || (GraphBuffer[i-1] < GraphBuffer[i] && dir == 0 && GraphBuffer[i] < lmin))
{
lc = i - lastval;
lastval = i;
// Switch depending on lc length:
// Tolerance is 1/8 of clock rate (arbitrary)
if (abs(lc-clock/4) < tolerance) {
// 16T0
if((i - pmc) == lc) { /* 16T0 was previous one */
/* It's a PMC ! */
i += (128+127+16+32+33+16)-1;
lastval = i;
pmc = 0;
block_done = 1;
}
else {
pmc = i;
}
} else if (abs(lc-clock/2) < tolerance) {
// 32TO
if((i - pmc) == lc) { /* 16T0 was previous one */
/* It's a PMC ! */
i += (128+127+16+32+33)-1;
lastval = i;
pmc = 0;
block_done = 1;
}
else if(half_switch == 1) {
BitStream[bitidx++] = 0;
half_switch = 0;
}
else
half_switch++;
} else if (abs(lc-clock) < tolerance) {
// 64TO
BitStream[bitidx++] = 1;
} else {
// Error
warnings++;
if (warnings > 10)
{
Dbprintf("Error: too many detection errors, aborting.");
return 0;
}
}
if(block_done == 1) {
if(bitidx == 128) {
for(j=0; j<16; j++) {
Blocks[num_blocks][j] = 128*BitStream[j*8+7]+
64*BitStream[j*8+6]+
32*BitStream[j*8+5]+
16*BitStream[j*8+4]+
8*BitStream[j*8+3]+
4*BitStream[j*8+2]+
2*BitStream[j*8+1]+
BitStream[j*8];
}
num_blocks++;
}
bitidx = 0;
block_done = 0;
half_switch = 0;
}
if (GraphBuffer[i-1] > GraphBuffer[i]) dir=0;
else dir = 1;
}
if(bitidx==255)
bitidx=0;
warnings = 0;
if(num_blocks == 4) break;
}
memcpy(outBlocks, Blocks, 16*num_blocks);
return num_blocks;
}
int IsBlock0PCF7931(uint8_t *Block) {
// Assume RFU means 0 :)
if((memcmp(Block, "\x00\x00\x00\x00\x00\x00\x00\x01", 8) == 0) && memcmp(Block+9, "\x00\x00\x00\x00\x00\x00\x00", 7) == 0) // PAC enabled
return 1;
if((memcmp(Block+9, "\x00\x00\x00\x00\x00\x00\x00", 7) == 0) && Block[7] == 0) // PAC disabled, can it *really* happen ?
return 1;
return 0;
}
int IsBlock1PCF7931(uint8_t *Block) {
// Assume RFU means 0 :)
if(Block[10] == 0 && Block[11] == 0 && Block[12] == 0 && Block[13] == 0)
if((Block[14] & 0x7f) <= 9 && Block[15] <= 9)
return 1;
return 0;
}
#define ALLOC 16
void ReadPCF7931() {
uint8_t Blocks[8][17];
uint8_t tmpBlocks[4][16];
int i, j, ind, ind2, n;
int num_blocks = 0;
int max_blocks = 8;
int ident = 0;
int error = 0;
int tries = 0;
memset(Blocks, 0, 8*17*sizeof(uint8_t));
do {
memset(tmpBlocks, 0, 4*16*sizeof(uint8_t));
n = DemodPCF7931((uint8_t**)tmpBlocks);
if(!n)
error++;
if(error==10 && num_blocks == 0) {
Dbprintf("Error, no tag or bad tag");
return;
}
else if (tries==20 || error==10) {
Dbprintf("Error reading the tag");
Dbprintf("Here is the partial content");
goto end;
}
for(i=0; i<n; i++)
Dbprintf("(dbg) %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
tmpBlocks[i][0], tmpBlocks[i][1], tmpBlocks[i][2], tmpBlocks[i][3], tmpBlocks[i][4], tmpBlocks[i][5], tmpBlocks[i][6], tmpBlocks[i][7],
tmpBlocks[i][8], tmpBlocks[i][9], tmpBlocks[i][10], tmpBlocks[i][11], tmpBlocks[i][12], tmpBlocks[i][13], tmpBlocks[i][14], tmpBlocks[i][15]);
if(!ident) {
for(i=0; i<n; i++) {
if(IsBlock0PCF7931(tmpBlocks[i])) {
// Found block 0 ?
if(i < n-1 && IsBlock1PCF7931(tmpBlocks[i+1])) {
// Found block 1!
// \o/
ident = 1;
memcpy(Blocks[0], tmpBlocks[i], 16);
Blocks[0][ALLOC] = 1;
memcpy(Blocks[1], tmpBlocks[i+1], 16);
Blocks[1][ALLOC] = 1;
max_blocks = max((Blocks[1][14] & 0x7f), Blocks[1][15]) + 1;
// Debug print
Dbprintf("(dbg) Max blocks: %d", max_blocks);
num_blocks = 2;
// Handle following blocks
for(j=i+2, ind2=2; j!=i; j++, ind2++, num_blocks++) {
if(j==n) j=0;
if(j==i) break;
memcpy(Blocks[ind2], tmpBlocks[j], 16);
Blocks[ind2][ALLOC] = 1;
}
break;
}
}
}
}
else {
for(i=0; i<n; i++) { // Look for identical block in known blocks
if(memcmp(tmpBlocks[i], "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16)) { // Block is not full of 00
for(j=0; j<max_blocks; j++) {
if(Blocks[j][ALLOC] == 1 && !memcmp(tmpBlocks[i], Blocks[j], 16)) {
// Found an identical block
for(ind=i-1,ind2=j-1; ind >= 0; ind--,ind2--) {
if(ind2 < 0)
ind2 = max_blocks;
if(!Blocks[ind2][ALLOC]) { // Block ind2 not already found
// Dbprintf("Tmp %d -> Block %d", ind, ind2);
memcpy(Blocks[ind2], tmpBlocks[ind], 16);
Blocks[ind2][ALLOC] = 1;
num_blocks++;
if(num_blocks == max_blocks) goto end;
}
}
for(ind=i+1,ind2=j+1; ind < n; ind++,ind2++) {
if(ind2 > max_blocks)
ind2 = 0;
if(!Blocks[ind2][ALLOC]) { // Block ind2 not already found
// Dbprintf("Tmp %d -> Block %d", ind, ind2);
memcpy(Blocks[ind2], tmpBlocks[ind], 16);
Blocks[ind2][ALLOC] = 1;
num_blocks++;
if(num_blocks == max_blocks) goto end;
}
}
}
}
}
}
}
tries++;
if (BUTTON_PRESS()) return;
} while (num_blocks != max_blocks);
end:
Dbprintf("-----------------------------------------");
Dbprintf("Memory content:");
Dbprintf("-----------------------------------------");
for(i=0; i<max_blocks; i++) {
if(Blocks[i][ALLOC]==1)
Dbprintf("%02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x %02x",
Blocks[i][0], Blocks[i][1], Blocks[i][2], Blocks[i][3], Blocks[i][4], Blocks[i][5], Blocks[i][6], Blocks[i][7],
Blocks[i][8], Blocks[i][9], Blocks[i][10], Blocks[i][11], Blocks[i][12], Blocks[i][13], Blocks[i][14], Blocks[i][15]);
else
Dbprintf("<missing block %d>", i);
}
Dbprintf("-----------------------------------------");
return ;
}

View file

@ -68,7 +68,8 @@ CMDSRCS = \
cmdlfti.c \
cmdparser.c \
cmdmain.c \
cmdlft55xx.c
cmdlft55xx.c \
cmdlfpcf7931.c
CMDOBJS = $(CMDSRCS:%.c=$(OBJDIR)/%.o)

View file

@ -25,6 +25,7 @@
#include "cmdlfem4x.h"
#include "cmdlfhitag.h"
#include "cmdlft55xx.h"
#include "cmdlfpcf7931.h"
static int CmdHelp(const char *Cmd);
@ -540,6 +541,7 @@ static command_t CommandTable[] =
{"hitag", CmdLFHitag, 1, "{ Hitag tags and transponders... }"},
{"vchdemod", CmdVchDemod, 1, "['clone'] -- Demodulate samples for VeriChip"},
{"t55xx", CmdLFT55XX, 1, "{ T55xx RFIDs... }"},
{"pcf7931", CmdLFPCF7931, 1, "{PCF7931 RFIDs...}"},
{NULL, NULL, 0, NULL}
};

49
client/cmdlfpcf7931.c Normal file
View file

@ -0,0 +1,49 @@
//-----------------------------------------------------------------------------
// Copyright (C) 2012 Chalk <chalk.secu at gmail.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 PCF7931 commands
//-----------------------------------------------------------------------------
#include <stdio.h>
#include <string.h>
#include "proxusb.h"
#include "ui.h"
#include "graph.h"
#include "cmdparser.h"
#include "cmddata.h"
#include "cmdmain.h"
#include "cmdlf.h"
#include "cmdlfpcf7931.h"
static int CmdHelp(const char *Cmd);
int CmdLFPCF7931Read(const char *Cmd)
{
UsbCommand c = {CMD_PCF7931_READ};
SendCommand(&c);
WaitForResponse(CMD_ACK);
return 0;
}
static command_t CommandTable[] =
{
{"help", CmdHelp, 1, "This help"},
{"read", CmdLFPCF7931Read, 1, "Read content of a PCF7931 transponder"},
{NULL, NULL, 0, NULL}
};
int CmdLFPCF7931(const char *Cmd)
{
CmdsParse(CommandTable, Cmd);
return 0;
}
int CmdHelp(const char *Cmd)
{
CmdsHelp(CommandTable);
return 0;
}

18
client/cmdlfpcf7931.h Normal file
View file

@ -0,0 +1,18 @@
//-----------------------------------------------------------------------------
// Copyright (C) 2012 Chalk <chalk.secu at gmail.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 PCF7931 commands
//-----------------------------------------------------------------------------
#ifndef CMDLFPCF7931_H__
#define CMDLFPCF7931_H__
int CmdLFPCF7931(const char *Cmd);
int CmdLFPCF7931Read(const char *Cmd);
#endif

View file

@ -74,6 +74,7 @@ typedef struct {
#define CMD_T55XX_READ_BLOCK 0x0214
#define CMD_T55XX_WRITE_BLOCK 0x0215
#define CMD_T55XX_READ_TRACE 0x0216
#define CMD_PCF7931_READ 0x0217
/* CMD_SET_ADC_MUX: ext1 is 0 for lopkd, 1 for loraw, 2 for hipkd, 3 for hiraw */