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PCF7931: improved read code and implemented a simple password bruteforce (#745)

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* Improved PCF 7931 read code and implemented a simple PCF7931 password bruteforce
* Warning on the PCF7931 bruteforce command
This commit is contained in:
Samuele 2019-01-06 18:33:06 +01:00 committed by pwpiwi
parent 5a28b51036
commit 818e15b0c8
6 changed files with 349 additions and 237 deletions
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3
armsrc/appmain.c
View file

@ -1059,6 +1059,9 @@ void UsbPacketReceived(uint8_t *packet, int len)
case CMD_PCF7931_WRITE:
WritePCF7931(c->d.asBytes[0],c->d.asBytes[1],c->d.asBytes[2],c->d.asBytes[3],c->d.asBytes[4],c->d.asBytes[5],c->d.asBytes[6], c->d.asBytes[9], c->d.asBytes[7]-128,c->d.asBytes[8]-128, c->arg[0], c->arg[1], c->arg[2]);
break;
case CMD_PCF7931_BRUTEFORCE:
BruteForcePCF7931(c->arg[0], (c->arg[1] & 0xFF), c->d.asBytes[9], c->d.asBytes[7]-128,c->d.asBytes[8]-128);
break;
case CMD_EM4X_READ_WORD:
EM4xReadWord(c->arg[0], c->arg[1],c->arg[2]);
break;

521
armsrc/pcf7931.c
View file

@ -8,23 +8,21 @@
#define T0_PCF 8 //period for the pcf7931 in us
#define ALLOC 16
int DemodPCF7931(uint8_t **outBlocks) {
uint8_t bits[256] = {0x00};
size_t DemodPCF7931(uint8_t **outBlocks) {
uint8_t bits[256] = {0x00};
uint8_t blocks[8][16];
uint8_t *dest = BigBuf_get_addr();
uint8_t *dest = BigBuf_get_addr();
int GraphTraceLen = BigBuf_max_traceLen();
if ( GraphTraceLen > 18000 )
if (GraphTraceLen > 18000)
GraphTraceLen = 18000;
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;
size_t num_blocks = 0;
int lmin=128, lmax=128;
uint8_t dir;
//clear read buffer
@ -39,17 +37,16 @@ int DemodPCF7931(uint8_t **outBlocks) {
i = 2;
/* Find first local max/min */
if(dest[1] > dest[0]) {
if(dest[1] > dest[0]) {
while(i < GraphTraceLen) {
if( !(dest[i] > dest[i-1]) && dest[i] > lmax)
if( !(dest[i] > dest[i-1]) && dest[i] > lmax)
break;
i++;
}
dir = 0;
}
else {
} else {
while(i < GraphTraceLen) {
if( !(dest[i] < dest[i-1]) && dest[i] < lmin)
if( !(dest[i] < dest[i-1]) && dest[i] < lmin)
break;
i++;
}
@ -61,10 +58,8 @@ int DemodPCF7931(uint8_t **outBlocks) {
pmc = 0;
block_done = 0;
for (bitidx = 0; i < GraphTraceLen; i++)
{
if ( (dest[i-1] > dest[i] && dir == 1 && dest[i] > lmax) || (dest[i-1] < dest[i] && dir == 0 && dest[i] < lmin))
{
for (bitidx = 0; i < GraphTraceLen; i++) {
if ((dest[i-1] > dest[i] && dir == 1 && dest[i] > lmax) || (dest[i-1] < dest[i] && dir == 0 && dest[i] < lmin)) {
lc = i - lastval;
lastval = i;
@ -78,8 +73,7 @@ int DemodPCF7931(uint8_t **outBlocks) {
lastval = i;
pmc = 0;
block_done = 1;
}
else {
} else {
pmc = i;
}
} else if (ABS(lc-clock/2) < tolerance) {
@ -90,21 +84,18 @@ int DemodPCF7931(uint8_t **outBlocks) {
lastval = i;
pmc = 0;
block_done = 1;
}
else if(half_switch == 1) {
bits[bitidx++] = 0;
} else if(half_switch == 1) {
bits[bitidx++] = 0;
half_switch = 0;
}
else
half_switch++;
} else if (ABS(lc-clock) < tolerance) {
// 64TO
bits[bitidx++] = 1;
bits[bitidx++] = 1;
} else {
// Error
warnings++;
if (warnings > 10)
{
if (++warnings > 10) {
Dbprintf("Error: too many detection errors, aborting.");
return 0;
}
@ -112,16 +103,17 @@ int DemodPCF7931(uint8_t **outBlocks) {
if(block_done == 1) {
if(bitidx == 128) {
for(j=0; j<16; j++) {
blocks[num_blocks][j] = 128*bits[j*8+7]+
64*bits[j*8+6]+
32*bits[j*8+5]+
16*bits[j*8+4]+
8*bits[j*8+3]+
4*bits[j*8+2]+
2*bits[j*8+1]+
bits[j*8];
for(j = 0; j < 16; ++j) {
blocks[num_blocks][j] =
128 * bits[j*8 + 7]+
64 * bits[j*8 + 6] +
32 * bits[j*8 + 5] +
16 * bits[j*8 + 4] +
8 * bits[j*8 + 3] +
4 * bits[j*8 + 2] +
2 * bits[j*8 + 1] +
bits[j*8]
;
}
num_blocks++;
}
@ -130,272 +122,349 @@ int DemodPCF7931(uint8_t **outBlocks) {
half_switch = 0;
}
if(i < GraphTraceLen)
dir =(dest[i-1] > dest[i]) ? 0 : 1;
dir = (dest[i-1] > dest[i]) ? 0 : 1;
}
if(bitidx==255)
bitidx=0;
warnings = 0;
if(num_blocks == 4) break;
}
memcpy(outBlocks, blocks, 16*num_blocks);
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;
bool IsBlock0PCF7931(uint8_t *block) {
// assuming all RFU bits are set to 0
// if PAC is enabled password is set to 0
if (block[7] == 0x01)
{
if (!memcmp(block, "\x00\x00\x00\x00\x00\x00\x00", 7) && !memcmp(block+9, "\x00\x00\x00\x00\x00\x00\x00", 7))
return true;
}
else if (block[7] == 0x00)
{
if (!memcmp(block+9, "\x00\x00\x00\x00\x00\x00\x00", 7))
return true;
}
return false;
}
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;
bool IsBlock1PCF7931(uint8_t *block) {
// assuming all RFU bits are set to 0
if (block[10] == 0 && block[11] == 0 && block[12] == 0 && block[13] == 0)
if((block[14] & 0x7f) <= 9 && block[15] <= 9)
return true;
return 0;
return false;
}
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;
int found_blocks = 0; // successfully read blocks
int max_blocks = 8; // readable blocks
uint8_t memory_blocks[8][17]; // PCF content
uint8_t single_blocks[8][17]; // PFC blocks with unknown position
int single_blocks_cnt = 0;
memset(Blocks, 0, 8*17*sizeof(uint8_t));
size_t n = 0; // transmitted blocks
uint8_t tmp_blocks[4][16]; // temporary read buffer
uint8_t found_0_1 = 0; // flag: blocks 0 and 1 were found
int errors = 0; // error counter
int tries = 0; // tries counter
memset(memory_blocks, 0, 8*17*sizeof(uint8_t));
memset(single_blocks, 0, 8*17*sizeof(uint8_t));
int i = 0, j = 0;
do {
memset(tmpBlocks, 0, 4*16*sizeof(uint8_t));
n = DemodPCF7931((uint8_t**)tmpBlocks);
i = 0;
memset(tmp_blocks, 0, 4*16*sizeof(uint8_t));
n = DemodPCF7931((uint8_t**)tmp_blocks);
if(!n)
error++;
if(error==10 && num_blocks == 0) {
++errors;
// exit if no block is received
if (errors >= 10 && found_blocks == 0 && single_blocks_cnt == 0) {
Dbprintf("Error, no tag or bad tag");
return;
}
else if (tries==20 || error==10) {
// exit if too many errors during reading
if (tries > 50 && (2*errors > tries)) {
Dbprintf("Error reading the tag");
Dbprintf("Here is the partial content");
goto end;
}
// our logic breaks if we don't get at least two blocks
if (n < 2) {
if (n == 0 || !memcmp(tmp_blocks[0], "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16))
continue;
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;
}
if (single_blocks_cnt < max_blocks) {
for (i = 0; i < single_blocks_cnt; ++i) {
if (!memcmp(single_blocks[i], tmp_blocks[0], 16)) {
j = 1;
break;
}
}
if (j != 1) {
memcpy(single_blocks[single_blocks_cnt], tmp_blocks[0], 16);
single_blocks_cnt++;
}
j = 0;
}
}
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;
continue;
}
Dbprintf("(dbg) got %d blocks (%d/%d found) (%d tries, %d errors)", n, found_blocks, (max_blocks == 0 ? found_blocks : max_blocks), tries, errors);
i = 0;
if(!found_0_1) {
while (i < n - 1) {
if (IsBlock0PCF7931(tmp_blocks[i]) && IsBlock1PCF7931(tmp_blocks[i+1])) {
found_0_1 = 1;
memcpy(memory_blocks[0], tmp_blocks[i], 16);
memcpy(memory_blocks[1], tmp_blocks[i+1], 16);
memory_blocks[0][ALLOC] = memory_blocks[1][ALLOC] = 1;
// block 1 tells how many blocks are going to be sent
max_blocks = MAX((memory_blocks[1][14] & 0x7f), memory_blocks[1][15]) + 1;
found_blocks = 2;
Dbprintf("Found blocks 0 and 1. PCF is transmitting %d blocks.", max_blocks);
// handle the following blocks
for (j = i + 2; j < n; ++j) {
memcpy(memory_blocks[found_blocks], tmp_blocks[j], 16);
memory_blocks[found_blocks][ALLOC] = 1;
++found_blocks;
}
break;
}
++i;
}
} else {
// Trying to re-order blocks
// Look for identical block in memory blocks
while (i < n-1) {
// skip all zeroes blocks
if (memcmp(tmp_blocks[i], "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16)) {
for (j = 1; j < max_blocks - 1; ++j) {
if (!memcmp(tmp_blocks[i], memory_blocks[j], 16) && !memory_blocks[j+1][ALLOC]) {
memcpy(memory_blocks[j+1], tmp_blocks[i+1], 16);
memory_blocks[j+1][ALLOC] = 1;
if (++found_blocks >= max_blocks) goto end;
}
}
}
if (memcmp(tmp_blocks[i+1], "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", 16)) {
for (j = 0; j < max_blocks; ++j) {
if (!memcmp(tmp_blocks[i+1], memory_blocks[j], 16) && !memory_blocks[(j == 0 ? max_blocks : j) -1][ALLOC]) {
if (j == 0) {
memcpy(memory_blocks[max_blocks - 1], tmp_blocks[i], 16);
memory_blocks[max_blocks - 1][ALLOC] = 1;
} else {
memcpy(memory_blocks[j-1], tmp_blocks[i], 16);
memory_blocks[j-1][ALLOC] = 1;
}
if (++found_blocks >= max_blocks) goto end;
}
}
}
++i;
}
}
tries++;
if (BUTTON_PRESS()) return;
} while (num_blocks != max_blocks);
++tries;
if (BUTTON_PRESS()) {
Dbprintf("Button pressed, stopping.");
goto end;
}
}
while (found_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]);
for (i = 0; i < max_blocks; ++i) {
if (memory_blocks[i][ALLOC])
print_result("Block", memory_blocks[i], 16);
else
Dbprintf("<missing block %d>", i);
}
Dbprintf("-----------------------------------------");
if (found_blocks < max_blocks) {
Dbprintf("-----------------------------------------");
Dbprintf("Blocks with unknown position:");
Dbprintf("-----------------------------------------");
for (i = 0; i < single_blocks_cnt; ++i)
print_result("Block", single_blocks[i], 16);
Dbprintf("-----------------------------------------");
}
cmd_send(CMD_ACK,0,0,0,0,0);
}
/* Write on a byte of a PCF7931 tag
* @param address : address of the block to write
@param byte : address of the byte to write
@param data : data to write
*/
void WritePCF7931(uint8_t pass1, uint8_t pass2, uint8_t pass3, uint8_t pass4, uint8_t pass5, uint8_t pass6, uint8_t pass7, uint16_t init_delay, int32_t l, int32_t p, uint8_t address, uint8_t byte, uint8_t data)
{
static void RealWritePCF7931(uint8_t *pass, uint16_t init_delay, int32_t l, int32_t p, uint8_t address, uint8_t byte, uint8_t data) {
uint32_t tab[1024]={0}; // data times frame
uint32_t u = 0;
uint8_t parity = 0;
bool comp = 0;
//BUILD OF THE DATA FRAME
//alimentation of the tag (time for initializing)
AddPatternPCF7931(init_delay, 0, 8192/2*T0_PCF, tab);
//PMC
Dbprintf("Initialization delay : %d us", init_delay);
AddPatternPCF7931(8192/2*T0_PCF + 319*T0_PCF+70, 3*T0_PCF, 29*T0_PCF, tab);
Dbprintf("Offsets : %d us on the low pulses width, %d us on the low pulses positions", l, p);
//password indication bit
AddBitPCF7931(1, tab, l, p);
//password (on 56 bits)
Dbprintf("Password (LSB first on each byte) : %02x %02x %02x %02x %02x %02x %02x", pass1,pass2,pass3,pass4,pass5,pass6,pass7);
AddBytePCF7931(pass1, tab, l, p);
AddBytePCF7931(pass2, tab, l, p);
AddBytePCF7931(pass3, tab, l, p);
AddBytePCF7931(pass4, tab, l, p);
AddBytePCF7931(pass5, tab, l, p);
AddBytePCF7931(pass6, tab, l, p);
AddBytePCF7931(pass7, tab, l, p);
// password (on 56 bits)
AddBytePCF7931(pass[0], tab, l, p);
AddBytePCF7931(pass[1], tab, l, p);
AddBytePCF7931(pass[2], tab, l, p);
AddBytePCF7931(pass[3], tab, l, p);
AddBytePCF7931(pass[4], tab, l, p);
AddBytePCF7931(pass[5], tab, l, p);
AddBytePCF7931(pass[6], tab, l, p);
//programming mode (0 or 1)
AddBitPCF7931(0, tab, l, p);
//block adress on 6 bits
Dbprintf("Block address : %02x", address);
for (u=0; u<6; u++)
{
if (address&(1<<u)) { // bit 1
parity++;
for (u = 0; u < 6; ++u) {
if (address & (1 << u)) { // bit 1
++parity;
AddBitPCF7931(1, tab, l, p);
} else{ // bit 0
} else { // bit 0
AddBitPCF7931(0, tab, l, p);
}
}
//byte address on 4 bits
Dbprintf("Byte address : %02x", byte);
for (u=0; u<4; u++)
for (u = 0; u < 4; ++u)
{
if (byte&(1<<u)) { // bit 1
if (byte & (1 << u)) { // bit 1
parity++;
AddBitPCF7931(1, tab, l, p);
} else{ // bit 0
AddBitPCF7931(0, tab, l, p);
}
else // bit 0
AddBitPCF7931(0, tab, l, p);
}
//data on 8 bits
Dbprintf("Data : %02x", data);
for (u=0; u<8; u++)
{
if (data&(1<<u)) { // bit 1
parity++;
AddBitPCF7931(1, tab, l, p);
} else{ //bit 0
}
else //bit 0
AddBitPCF7931(0, tab, l, p);
}
}
//parity bit
if((parity%2)==0){
if ((parity % 2) == 0)
AddBitPCF7931(0, tab, l, p); //even parity
}else{
else
AddBitPCF7931(1, tab, l, p);//odd parity
}
//time access memory
AddPatternPCF7931(5120+2680, 0, 0, tab);
//conversion of the scale time
for(u=0;u<500;u++){
tab[u]=(tab[u] * 3)/2;
}
for (u = 0; u < 500; ++u)
tab[u] = (tab[u] * 3) / 2;
//compennsation of the counter reload
while (!comp){
while (!comp) {
comp = 1;
for(u=0;tab[u]!=0;u++){
if(tab[u] > 0xFFFF){
for (u = 0; tab[u] != 0; ++u)
if(tab[u] > 0xFFFF) {
tab[u] -= 0xFFFF;
comp = 0;
}
}
}
SendCmdPCF7931(tab);
}
void BruteForcePCF7931(uint64_t password, uint8_t tries, uint16_t init_delay, int32_t l, int32_t p) {
uint8_t i = 0;
uint8_t pass_array[7];
while (password < 0x00FFFFFFFFFFFFFF) {
if (BUTTON_PRESS()) {
Dbprintf("Button pressed, stopping bruteforce ...");
return;
}
pass_array[0] = password & 0xFF;
pass_array[1] = (password >> 8) & 0xFF;
pass_array[2] = (password >> 16) & 0xFF;
pass_array[3] = (password >> 24) & 0xFF;
pass_array[4] = (password >> 32) & 0xFF;
pass_array[5] = (password >> 40) & 0xFF;
pass_array[6] = (password >> 48) & 0xFF;
Dbprintf("Trying: %02x %02x %02x %02x %02x %02x %02x ...",
pass_array[0],
pass_array[1],
pass_array[2],
pass_array[3],
pass_array[4],
pass_array[5],
pass_array[6]);
for (i = 0; i < tries; ++i)
RealWritePCF7931
(
pass_array,
init_delay,
l,
p,
0,
7,
0x01
);
++password;
}
}
/* Write on a byte of a PCF7931 tag
* @param address : address of the block to write
@param byte : address of the byte to write
@param data : data to write
*/
void WritePCF7931(uint8_t pass1, uint8_t pass2, uint8_t pass3, uint8_t pass4, uint8_t pass5, uint8_t pass6, uint8_t pass7, uint16_t init_delay, int32_t l, int32_t p, uint8_t address, uint8_t byte, uint8_t data) {
Dbprintf("Initialization delay : %d us", init_delay);
Dbprintf("Offsets : %d us on the low pulses width, %d us on the low pulses positions", l, p);
Dbprintf("Password (LSB first on each byte): %02x %02x %02x %02x %02x %02x %02x", pass1, pass2, pass3, pass4, pass5, pass6, pass7);
Dbprintf("Block address : %02x", address);
Dbprintf("Byte address : %02x", byte);
Dbprintf("Data : %02x", data);
uint8_t password[7] = {pass1, pass2, pass3, pass4, pass5, pass6, pass7};
RealWritePCF7931 (password, init_delay, l, p, address, byte, data);
}
/* Send a trame to a PCF7931 tags
* @param tab : array of the data frame
*/
void SendCmdPCF7931(uint32_t * tab){
void SendCmdPCF7931(uint32_t * tab) {
uint16_t u=0;
uint16_t tempo=0;
Dbprintf("SENDING DATA FRAME...");
Dbprintf("Sending data frame ...");
FpgaDownloadAndGo(FPGA_BITSTREAM_LF);
FpgaSendCommand(FPGA_CMD_SET_DIVISOR, 95); //125Khz
FpgaWriteConfWord(FPGA_MAJOR_MODE_LF_PASSTHRU );
LED_A_ON();
@ -412,41 +481,30 @@ void SendCmdPCF7931(uint32_t * tab){
AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKEN;
AT91C_BASE_TCB->TCB_BCR = 1;
tempo = AT91C_BASE_TC0->TC_CV;
for(u=0;tab[u]!= 0;u+=3){
for (u = 0; tab[u] != 0; u += 3) {
// modulate antenna
HIGH(GPIO_SSC_DOUT);
while(tempo != tab[u]){
while(tempo != tab[u])
tempo = AT91C_BASE_TC0->TC_CV;
}
// stop modulating antenna
LOW(GPIO_SSC_DOUT);
while(tempo != tab[u+1]){
while(tempo != tab[u+1])
tempo = AT91C_BASE_TC0->TC_CV;
}
// modulate antenna
HIGH(GPIO_SSC_DOUT);
while(tempo != tab[u+2]){
while(tempo != tab[u+2])
tempo = AT91C_BASE_TC0->TC_CV;
}
}
LED_A_OFF();
FpgaWriteConfWord(FPGA_MAJOR_MODE_OFF);
SpinDelay(200);
AT91C_BASE_TC0->TC_CCR = AT91C_TC_CLKDIS; // timer disable
DbpString("FINISH !");
DbpString("(Could be usefull to send the same trame many times)");
DbpString("Data frame sent (multiple sends may be needed)");
LED(0xFFFF, 1000);
}
@ -457,15 +515,12 @@ void SendCmdPCF7931(uint32_t * tab){
* @param l : offset on low pulse width
* @param p : offset on low pulse positioning
*/
bool AddBytePCF7931(uint8_t byte, uint32_t * tab, int32_t l, int32_t p){
bool AddBytePCF7931(uint8_t byte, uint32_t * tab, int32_t l, int32_t p) {
uint32_t u;
for (u=0; u<8; u++)
{
if (byte&(1<<u)) { //bit à 1
for (u = 0; u < 8; ++u) {
if (byte & (1 << u)) { //bit is 1
if(AddBitPCF7931(1, tab, l, p)==1)return 1;
} else { //bit à 0
} else { //bit is 0
if(AddBitPCF7931(0, tab, l, p)==1)return 1;
}
}
@ -479,29 +534,27 @@ bool AddBytePCF7931(uint8_t byte, uint32_t * tab, int32_t l, int32_t p){
* @param l : offset on low pulse width
* @param p : offset on low pulse positioning
*/
bool AddBitPCF7931(bool b, uint32_t * tab, int32_t l, int32_t p){
bool AddBitPCF7931(bool b, uint32_t * tab, int32_t l, int32_t p) {
uint8_t u = 0;
for(u=0;tab[u]!=0;u+=3){} //we put the cursor at the last value of the array
for (u = 0; tab[u] != 0; u += 3){} //we put the cursor at the last value of the array
if(b==1){ //add a bit 1
if(u==0) tab[u] = 34*T0_PCF+p;
else tab[u] = 34*T0_PCF+tab[u-1]+p;
if (b == 1) { //add a bit 1
if (u == 0) tab[u] = 34 * T0_PCF + p;
else tab[u] = 34 * T0_PCF + tab[u-1] + p;
tab[u+1] = 6*T0_PCF+tab[u]+l;
tab[u+2] = 88*T0_PCF+tab[u+1]-l-p;
tab[u+1] = 6 * T0_PCF+tab[u] + l;
tab[u+2] = 88 * T0_PCF+tab[u + 1] - l - p;
return 0;
}else{ //add a bit 0
} else { //add a bit 0
if(u==0) tab[u] = 98*T0_PCF+p;
else tab[u] = 98*T0_PCF+tab[u-1]+p;
if (u == 0) tab[u] = 98 * T0_PCF + p;
else tab[u] = 98 * T0_PCF + tab[u-1] + p;
tab[u+1] = 6*T0_PCF+tab[u]+l;
tab[u+2] = 24*T0_PCF+tab[u+1]-l-p;
tab[u + 1] = 6 * T0_PCF + tab[u] + l;
tab[u + 2] = 24 * T0_PCF + tab[u + 1] - l - p;
return 0;
}
return 1;
}
@ -512,15 +565,15 @@ bool AddBitPCF7931(bool b, uint32_t * tab, int32_t l, int32_t p){
* @param c : delay of the last high pulse
* @param tab : array of the data frame
*/
bool AddPatternPCF7931(uint32_t a, uint32_t b, uint32_t c, uint32_t * tab){
bool AddPatternPCF7931(uint32_t a, uint32_t b, uint32_t c, uint32_t * tab) {
uint32_t u = 0;
for(u=0;tab[u]!=0;u+=3){} //we put the cursor at the last value of the array
for(u = 0; tab[u] != 0; u += 3){} //we put the cursor at the last value of the array
if(u==0) tab[u] = a;
else tab[u] = a + tab[u-1];
if (u == 0) tab[u] = a;
else tab[u] = a + tab[u - 1];
tab[u+1] = b+tab[u];
tab[u+2] = c+tab[u+1];
tab[u + 1] = b + tab[u];
tab[u + 2] = c + tab[u + 1];
return 0;
}

7
armsrc/pcf7931.h
View file

@ -1,14 +1,15 @@
#ifndef __PCF7931_H
#define __PCF7931_H
int DemodPCF7931(uint8_t **outBlocks);
int IsBlock0PCF7931(uint8_t *Block);
int IsBlock1PCF7931(uint8_t *Block);
size_t DemodPCF7931(uint8_t **outBlocks);
bool IsBlock0PCF7931(uint8_t *Block);
bool IsBlock1PCF7931(uint8_t *Block);
void ReadPCF7931();
void SendCmdPCF7931(uint32_t * tab);
bool AddBytePCF7931(uint8_t byte, uint32_t * tab, int32_t l, int32_t p);
bool AddBitPCF7931(bool b, uint32_t * tab, int32_t l, int32_t p);
bool AddPatternPCF7931(uint32_t a, uint32_t b, uint32_t c, uint32_t * tab);
void WritePCF7931(uint8_t pass1, uint8_t pass2, uint8_t pass3, uint8_t pass4, uint8_t pass5, uint8_t pass6, uint8_t pass7, uint16_t init_delay, int32_t l, int32_t p, uint8_t address, uint8_t byte, uint8_t data);
void BruteForcePCF7931(uint64_t start_password, uint8_t tries, uint16_t init_delay, int32_t l, int32_t p);
#endif

51
client/cmdlfpcf7931.c
View file

@ -1,6 +1,7 @@
//-----------------------------------------------------------------------------
// Copyright (C) 2012 Chalk <chalk.secu at gmail.com>
// 2015 Dake <thomas.cayrou at gmail.com>
// 2018 sguerrini97 <sguerrini97 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
@ -76,6 +77,21 @@ int usage_pcf7931_write(){
return 0;
}
int usage_pcf7931_bruteforce()
{
PrintAndLog("Usage: lf pcf7931 bruteforce [h] <start password> <tries>");
PrintAndLog("This command tries to disable PAC of a PCF7931 transponder by bruteforcing the password.");
PrintAndLog("!! THIS IS NOT INTENDED TO RECOVER THE FULL PASSWORD !!");
PrintAndLog("!! DO NOT USE UNLESS THE FIRST 5 BYTES OF THE PASSWORD ARE KNOWN !!");
PrintAndLog("Options:");
PrintAndLog(" h This help");
PrintAndLog(" start password hex password to start from");
PrintAndLog(" tries How many times to send the same data frame");
PrintAndLog("Examples:");
PrintAndLog(" lf pcf7931 bruteforce 00000000123456 3");
return 0;
}
int usage_pcf7931_config(){
PrintAndLog("Usage: lf pcf7931 config [h] [r] <pwd> <delay> <offset width> <offset position>");
PrintAndLog("This command tries to set the configuration used with PCF7931 commands");
@ -159,12 +175,47 @@ int CmdLFPCF7931Write(const char *Cmd){
return 0;
}
int CmdLFPCF7931BruteForce(const char *Cmd){
uint8_t ctmp = param_getchar(Cmd, 0);
if (strlen(Cmd) < 1 || ctmp == 'h' || ctmp == 'H') return usage_pcf7931_bruteforce();
uint64_t start_password = 0;
uint8_t tries = 3;
if (param_gethex(Cmd, 0, (uint8_t*)(&start_password), 14)) return usage_pcf7931_bruteforce();
if (param_getdec(Cmd, 1, &tries)) return usage_pcf7931_bruteforce();
PrintAndLog("Bruteforcing from password: %02x %02x %02x %02x %02x %02x %02x",
start_password & 0xFF,
(start_password >> 8) & 0xFF,
(start_password >> 16) & 0xFF,
(start_password >> 24) & 0xFF,
(start_password >> 32) & 0xFF,
(start_password >> 48) & 0xFF,
(start_password >> 56) & 0xFF);
PrintAndLog("Trying each password %d times", tries);
UsbCommand c = {CMD_PCF7931_BRUTEFORCE, {start_password, tries} };
c.d.asDwords[7] = (configPcf.OffsetWidth + 128);
c.d.asDwords[8] = (configPcf.OffsetPosition + 128);
c.d.asDwords[9] = configPcf.InitDelay;
clearCommandBuffer();
SendCommand(&c);
//no ack?
return 0;
}
static command_t CommandTable[] =
{
{"help", CmdHelp, 1, "This help"},
{"read", CmdLFPCF7931Read, 0, "Read content of a PCF7931 transponder"},
{"write", CmdLFPCF7931Write, 0, "Write data on a PCF7931 transponder."},
{"config", CmdLFPCF7931Config, 1, "Configure the password, the tags initialization delay and time offsets (optional)"},
{"bruteforce", CmdLFPCF7931BruteForce, 0, "Bruteforce a PCF7931 transponder password."},
{NULL, NULL, 0, NULL}
};

3
client/cmdlfpcf7931.h
View file

@ -1,6 +1,7 @@
//-----------------------------------------------------------------------------
// Copyright (C) 2012 Chalk <chalk.secu at gmail.com>
// 2015 Dake <thomas.cayrou at gmail.com>
// 2018 sguerrini97 <sguerrini97 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
@ -26,12 +27,14 @@ int pcf7931_printConfig();
int usage_pcf7931_read();
int usage_pcf7931_write();
int usage_pcf7931_bruteforce();
int usage_pcf7931_config();
int CmdLFPCF7931(const char *Cmd);
int CmdLFPCF7931Read(const char *Cmd);
int CmdLFPCF7931Write(const char *Cmd);
int CmdLFPCF7931BruteForce(const char *Cmd);
int CmdLFPCF7931Config(const char *Cmd);
#endif

1
include/usb_cmd.h
View file

@ -97,6 +97,7 @@ typedef struct{
#define CMD_T55XX_RESET_READ 0x0216
#define CMD_PCF7931_READ 0x0217
#define CMD_PCF7931_WRITE 0x0222
#define CMD_PCF7931_BRUTEFORCE 0x0226
#define CMD_EM4X_READ_WORD 0x0218
#define CMD_EM4X_WRITE_WORD 0x0219
#define CMD_IO_DEMOD_FSK 0x021A