//-----------------------------------------------------------------------------
//
// 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 Farpoint G Prox II / Pyramid tag commands
// Biphase, rf/ , 96 bits (unknown key calc + some bits)
//-----------------------------------------------------------------------------
#include "cmdlfguard.h"
static int CmdHelp(const char *Cmd);
static int usage_lf_guard_clone(void) {
PrintAndLogEx(NORMAL, "clone a Guardall tag to a T55x7 tag.");
PrintAndLogEx(NORMAL, "The facility-code is 8-bit and the card number is 16-bit. Larger values are truncated. ");
PrintAndLogEx(NORMAL, "Currently work only on 26bit");
PrintAndLogEx(NORMAL, "");
PrintAndLogEx(NORMAL, "Usage: lf gprox clone [h] <format> <Facility-Code> <Card-Number>");
PrintAndLogEx(NORMAL, "Options:");
PrintAndLogEx(NORMAL, " <format> : format length 26|32|36|40");
PrintAndLogEx(NORMAL, " <Facility-Code> : 8-bit value facility code");
PrintAndLogEx(NORMAL, " <Card Number> : 16-bit value card number");
PrintAndLogEx(NORMAL, "");
PrintAndLogEx(NORMAL, "Examples:");
PrintAndLogEx(NORMAL, " lf gprox clone 26 123 11223");
return PM3_SUCCESS;
}
static int usage_lf_guard_sim(void) {
PrintAndLogEx(NORMAL, "Enables simulation of Guardall card with specified card number.");
PrintAndLogEx(NORMAL, "Simulation runs until the button is pressed or another USB command is issued.");
PrintAndLogEx(NORMAL, "The facility-code is 8-bit and the card number is 16-bit. Larger values are truncated.");
PrintAndLogEx(NORMAL, "Currently work only on 26bit");
PrintAndLogEx(NORMAL, "");
PrintAndLogEx(NORMAL, "Usage: lf gprox sim [h] <format> <Facility-Code> <Card-Number>");
PrintAndLogEx(NORMAL, "Options:");
PrintAndLogEx(NORMAL, " <format> : format length 26|32|36|40");
PrintAndLogEx(NORMAL, " <Facility-Code> : 8-bit value facility code");
PrintAndLogEx(NORMAL, " <Card Number> : 16-bit value card number");
PrintAndLogEx(NORMAL, "");
PrintAndLogEx(NORMAL, "Examples:");
PrintAndLogEx(NORMAL, " lf gprox sim 26 123 11223");
return PM3_SUCCESS;
}
//by marshmellow
//attempts to demodulate and identify a G_Prox_II verex/chubb card
//WARNING: if it fails during some points it will destroy the DemodBuffer data
// but will leave the GraphBuffer intact.
//if successful it will push askraw data back to demod buffer ready for emulation
static int CmdGuardDemod(const char *Cmd) {
(void)Cmd; // Cmd is not used so far
//Differential Biphase
//get binary from ask wave
if (ASKbiphaseDemod("0 64 0 0", false) != PM3_SUCCESS) {
PrintAndLogEx(DEBUG, "DEBUG: Error - gProxII ASKbiphaseDemod failed");
return PM3_ESOFT;
}
size_t size = DemodBufferLen;
int preambleIndex = detectGProxII(DemodBuffer, &size);
if (preambleIndex < 0) {
if (preambleIndex == -1)
PrintAndLogEx(DEBUG, "DEBUG: Error - gProxII too few bits found");
else if (preambleIndex == -2)
PrintAndLogEx(DEBUG, "DEBUG: Error - gProxII preamble not found");
else if (preambleIndex == -3)
PrintAndLogEx(DEBUG, "DEBUG: Error - gProxII size not correct: %d", size);
else if (preambleIndex == -5)
PrintAndLogEx(DEBUG, "DEBUG: Error - gProxII wrong spacerbits");
else
PrintAndLogEx(DEBUG, "DEBUG: Error - gProxII ans: %d", preambleIndex);
return PM3_ESOFT;
}
//got a good demod of 96 bits
uint8_t ByteStream[8] = {0x00};
uint8_t xorKey = 0;
size_t startIdx = preambleIndex + 6; //start after 6 bit preamble
uint8_t bits_no_spacer[90];
//so as to not mess with raw DemodBuffer copy to a new sample array
memcpy(bits_no_spacer, DemodBuffer + startIdx, 90);
// remove the 18 (90/5=18) parity bits (down to 72 bits (96-6-18=72))
size_t len = removeParity(bits_no_spacer, 0, 5, 3, 90); //source, startloc, paritylen, ptype, length_to_run
if (len != 72) {
PrintAndLogEx(DEBUG, "DEBUG: Error - gProxII spacer removal did not produce 72 bits: %u, start: %u", len, startIdx);
return PM3_ESOFT;
}
// get key and then get all 8 bytes of payload decoded
xorKey = (uint8_t)bytebits_to_byteLSBF(bits_no_spacer, 8);
for (size_t idx = 0; idx < 8; idx++) {
ByteStream[idx] = ((uint8_t)bytebits_to_byteLSBF(bits_no_spacer + 8 + (idx * 8), 8)) ^ xorKey;
PrintAndLogEx(DEBUG, "DEBUG: gProxII byte %u after xor: %02x", (unsigned int)idx, ByteStream[idx]);
}
setDemodBuff(DemodBuffer, 96, preambleIndex);
setClockGrid(g_DemodClock, g_DemodStartIdx + (preambleIndex * g_DemodClock));
//ByteStream contains 8 Bytes (64 bits) of decrypted raw tag data
uint8_t fmtLen = ByteStream[0] >> 2;
uint32_t FC = 0;
uint32_t Card = 0;
//get raw 96 bits to print
uint32_t raw1 = bytebits_to_byte(DemodBuffer, 32);
uint32_t raw2 = bytebits_to_byte(DemodBuffer + 32, 32);
uint32_t raw3 = bytebits_to_byte(DemodBuffer + 64, 32);
bool unknown = false;
switch (fmtLen) {
case 36:
FC = ((ByteStream[3] & 0x7F) << 7) | (ByteStream[4] >> 1);
Card = ((ByteStream[4] & 1) << 19) | (ByteStream[5] << 11) | (ByteStream[6] << 3) | (ByteStream[7] >> 5);
break;
case 26:
FC = ((ByteStream[3] & 0x7F) << 1) | (ByteStream[4] >> 7);
Card = ((ByteStream[4] & 0x7F) << 9) | (ByteStream[5] << 1) | (ByteStream[6] >> 7);
break;
default :
unknown = true;
break;
}
if (!unknown)
PrintAndLogEx(SUCCESS, "G-Prox-II Found: Format Len: %ubit - FC: %u - Card: %u, Raw: %08x%08x%08x", fmtLen, FC, Card, raw1, raw2, raw3);
else
PrintAndLogEx(SUCCESS, "Unknown G-Prox-II Fmt Found: Format Len: %u, Raw: %08x%08x%08x", fmtLen, raw1, raw2, raw3);
return PM3_SUCCESS;
}
static int CmdGuardRead(const char *Cmd) {
lf_read(true, 10000);
return CmdGuardDemod(Cmd);
}
static int CmdGuardClone(const char *Cmd) {
char cmdp = tolower(param_getchar(Cmd, 0));
if (strlen(Cmd) == 0 || cmdp == 'h') return usage_lf_guard_clone();
uint32_t facilitycode = 0, cardnumber = 0, fc = 0, cn = 0, fmtlen = 0;
uint8_t bs[96];
memset(bs, 0x00, sizeof(bs));
//GuardProxII - compat mode, ASK/Biphase, data rate 64, 3 data blocks
uint32_t blocks[4] = {T55x7_MODULATION_BIPHASE | T55x7_BITRATE_RF_64 | 3 << T55x7_MAXBLOCK_SHIFT, 0, 0, 0};
if (sscanf(Cmd, "%u %u %u", &fmtlen, &fc, &cn) != 3) return usage_lf_guard_clone();
fmtlen &= 0x7f;
facilitycode = (fc & 0x000000FF);
cardnumber = (cn & 0x0000FFFF);
if (getGuardBits(fmtlen, facilitycode, cardnumber, bs) != PM3_SUCCESS) {
PrintAndLogEx(WARNING, "Error with tag bitstream generation.");
return PM3_ESOFT;
}
// Q5
if (param_getchar(Cmd, 3) == 'Q' || param_getchar(Cmd, 3) == 'q')
blocks[0] = T5555_MODULATION_FSK2 | T5555_SET_BITRATE(50) | 3 << T5555_MAXBLOCK_SHIFT;
blocks[1] = bytebits_to_byte(bs, 32);
blocks[2] = bytebits_to_byte(bs + 32, 32);
blocks[3] = bytebits_to_byte(bs + 64, 32);
PrintAndLogEx(INFO, "Preparing to clone Guardall to T55x7 with Facility Code: %u, Card Number: %u", facilitycode, cardnumber);
print_blocks(blocks, 4);
PacketResponseNG resp;
// fast push mode
conn.block_after_ACK = true;
for (uint8_t i = 0; i < 4; i++) {
if (i == 3) {
// Disable fast mode on last packet
conn.block_after_ACK = false;
}
clearCommandBuffer();
t55xx_write_block_t ng;
ng.data = blocks[i];
ng.pwd = 0;
ng.blockno = i;
ng.flags = 0;
SendCommandNG(CMD_T55XX_WRITE_BLOCK, (uint8_t *)&ng, sizeof(ng));
if (!WaitForResponseTimeout(CMD_T55XX_WRITE_BLOCK, &resp, T55XX_WRITE_TIMEOUT)) {
PrintAndLogEx(WARNING, "Error occurred, device did not respond during write operation.");
return PM3_ETIMEOUT;
}
}
return PM3_SUCCESS;
}
static int CmdGuardSim(const char *Cmd) {
uint32_t facilitycode = 0, cardnumber = 0, fc = 0, cn = 0, fmtlen = 0;
char cmdp = tolower(param_getchar(Cmd, 0));
if (strlen(Cmd) == 0 || cmdp == 'h') return usage_lf_guard_sim();
if (sscanf(Cmd, "%u %u %u", &fmtlen, &fc, &cn) != 3) return usage_lf_guard_sim();
uint8_t bs[96];
memset(bs, 0x00, sizeof(bs));
fmtlen &= 0x7F;
facilitycode = (fc & 0x000000FF);
cardnumber = (cn & 0x0000FFFF);
if (getGuardBits(fmtlen, facilitycode, cardnumber, bs) != PM3_SUCCESS) {
PrintAndLogEx(WARNING, "Error with tag bitstream generation.");
return PM3_ESOFT;
}
PrintAndLogEx(SUCCESS, "Simulating Guardall - Facility Code: %u, CardNumber: %u", facilitycode, cardnumber);
// Guard uses: clk: 64, invert: 0, encoding: 2 (ASK Biphase)
lf_asksim_t *payload = calloc(1, sizeof(lf_asksim_t) + sizeof(bs));
payload->encoding = 2;
payload->invert = 0;
payload->separator = 0;
payload->clock = 64;
memcpy(payload->data, bs, sizeof(bs));
clearCommandBuffer();
SendCommandNG(CMD_ASK_SIM_TAG, (uint8_t *)payload, sizeof(lf_asksim_t) + sizeof(bs));
free(payload);
PacketResponseNG resp;
WaitForResponse(CMD_ASK_SIM_TAG, &resp);
PrintAndLogEx(INFO, "Done");
if (resp.status != PM3_EOPABORTED)
return resp.status;
return PM3_SUCCESS;
}
static command_t CommandTable[] = {
{"help", CmdHelp, AlwaysAvailable, "this help"},
{"demod", CmdGuardDemod, AlwaysAvailable, "demodulate a G Prox II tag from the GraphBuffer"},
{"read", CmdGuardRead, IfPm3Lf, "attempt to read and extract tag data from the antenna"},
{"clone", CmdGuardClone, IfPm3Lf, "clone Guardall tag"},
{"sim", CmdGuardSim, IfPm3Lf, "simulate Guardall tag"},
{NULL, NULL, NULL, NULL}
};
static int CmdHelp(const char *Cmd) {
(void)Cmd; // Cmd is not used so far
CmdsHelp(CommandTable);
return PM3_SUCCESS;
}
int CmdLFGuard(const char *Cmd) {
clearCommandBuffer();
return CmdsParse(CommandTable, Cmd);
}
// by marshmellow
// demod gProxIIDemod
// error returns as -x
// success returns start position in bitstream
// Bitstream must contain previously askrawdemod and biphasedemoded data
int detectGProxII(uint8_t *bits, size_t *size) {
size_t startIdx = 0;
uint8_t preamble[] = {1, 1, 1, 1, 1, 0};
// sanity check
if (*size < sizeof(preamble)) return -1;
if (!preambleSearch(bits, preamble, sizeof(preamble), size, &startIdx))
return -2; //preamble not found
//gProxII should be 96 bits
if (*size != 96) return -3;
//check first 6 spacer bits to verify format
if (!bits[startIdx + 5] && !bits[startIdx + 10] && !bits[startIdx + 15] && !bits[startIdx + 20] && !bits[startIdx + 25] && !bits[startIdx + 30]) {
//confirmed proper separator bits found
//return start position
return (int) startIdx;
}
return -5; //spacer bits not found - not a valid gproxII
}
int demodGuard(void) {
return CmdGuardDemod("");
}
// Works for 26bits.
int getGuardBits(uint8_t fmtlen, uint32_t fc, uint32_t cn, uint8_t *guardBits) {
uint8_t xorKey = 0x66;
uint8_t i;
uint8_t pre[96];
uint8_t rawbytes[12];
memset(pre, 0x00, sizeof(pre));
memset(rawbytes, 0x00, sizeof(rawbytes));
// add format length (decimal)
switch (fmtlen) {
case 32: {
rawbytes[1] = (32 << 2);
break;
}
case 36: {
// FC = ((ByteStream[3] & 0x7F)<<7) | (ByteStream[4]>>1);
// Card = ((ByteStream[4]&1)<<19) | (ByteStream[5]<<11) | (ByteStream[6]<<3) | (ByteStream[7]>>5);
rawbytes[1] = (36 << 2);
// Get 26 wiegand from FacilityCode, CardNumber
uint8_t wiegand[34];
memset(wiegand, 0x00, sizeof(wiegand));
num_to_bytebits(fc, 8, wiegand);
num_to_bytebits(cn, 26, wiegand + 8);
// add wiegand parity bits (dest, source, len)
wiegand_add_parity(pre, wiegand, 34);
break;
}
case 40: {
rawbytes[1] = (40 << 2);
break;
}
case 26:
default: {
rawbytes[1] = (26 << 2);
// Get 26 wiegand from FacilityCode, CardNumber
uint8_t wiegand[24];
memset(wiegand, 0x00, sizeof(wiegand));
num_to_bytebits(fc, 8, wiegand);
num_to_bytebits(cn, 16, wiegand + 8);
// add wiegand parity bits (dest, source, len)
wiegand_add_parity(pre, wiegand, 24);
break;
}
}
// 2bit checksum, unknown today,
// these two bits are the last ones of rawbyte[1], hence the LSHIFT above.
// xor key
rawbytes[0] = xorKey;
rawbytes[2] = 1;
rawbytes[3] = 0;
// add wiegand to rawbytes
for (i = 0; i < 4; ++i)
rawbytes[i + 4] = bytebits_to_byte(pre + (i * 8), 8);
PrintAndLogEx(DEBUG, " WIE | %s\n", sprint_hex(rawbytes, sizeof(rawbytes)));
// XOR (only works on wiegand stuff)
for (i = 1; i < 12; ++i)
rawbytes[i] ^= xorKey ;
PrintAndLogEx(DEBUG, " XOR | %s \n", sprint_hex(rawbytes, sizeof(rawbytes)));
// convert rawbytes to bits in pre
for (i = 0; i < 12; ++i)
num_to_bytebitsLSBF(rawbytes[i], 8, pre + (i * 8));
PrintAndLogEx(DEBUG, "\n Raw | %s \n", sprint_hex(rawbytes, sizeof(rawbytes)));
PrintAndLogEx(DEBUG, " Raw | %s\n", sprint_bin(pre, 64));
// add spacer bit 0 every 4 bits, starting with index 0,
// 12 bytes, 24 nibbles. 24+1 extra bites. 3bytes. ie 9bytes | 1byte xorkey, 8bytes rawdata (64bits, should be enough for a 40bit wiegand)
addParity(pre, guardBits + 6, 64, 5, 3);
// preamble
guardBits[0] = 1;
guardBits[1] = 1;
guardBits[2] = 1;
guardBits[3] = 1;
guardBits[4] = 1;
guardBits[5] = 0;
PrintAndLogEx(DEBUG, " FIN | %s\n", sprint_bin(guardBits, 96));
return PM3_SUCCESS;
}