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fixes for 36b format

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This commit is contained in:
iceman1001 2020-09-10 11:44:32 +02:00
parent 5689546ae0
commit 3221fb32a1
1 changed files with 29 additions and 29 deletions
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58
client/src/cmdlfguard.c
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@ -93,32 +93,35 @@ static int CmdGuardDemod(const char *Cmd) {
return PM3_ESOFT;
}
//got a good demod of 96 bits
uint8_t ByteStream[8] = {0x00};
// got a good demod of 96 bits
uint8_t plain[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
// 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: %zu, start: %zu", 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 %zu after xor: %02x", idx, ByteStream[idx]);
plain[idx] = ((uint8_t)bytebits_to_byteLSBF(bits_no_spacer + 8 + (idx * 8), 8)) ^ xorKey;
PrintAndLogEx(DEBUG, "DEBUG: gProxII byte %zu after xor: %02x", idx, plain[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;
//plain contains 8 Bytes (64 bits) of decrypted raw tag data
uint8_t fmtLen = plain[0] >> 2;
uint32_t FC = 0;
uint32_t Card = 0;
//get raw 96 bits to print
@ -128,12 +131,12 @@ static int CmdGuardDemod(const char *Cmd) {
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);
FC = ((plain[3] & 0x7F) << 7) | (plain[4] >> 1);
Card = ((plain[4] & 1) << 19) | (plain[5] << 11) | (plain[6] << 3) | ((plain[7] & 0xE0) >> 5);
break;
case 26:
FC = ((ByteStream[3] & 0x7F) << 1) | (ByteStream[4] >> 7);
Card = ((ByteStream[4] & 0x7F) << 9) | (ByteStream[5] << 1) | (ByteStream[6] >> 7);
FC = ((plain[3] & 0x7F) << 1) | (plain[4] >> 7);
Card = ((plain[4] & 0x7F) << 9) | (plain[5] << 1) | (plain[6] >> 7);
break;
default :
unknown = true;
@ -309,14 +312,12 @@ int getGuardBits(uint8_t fmtlen, uint32_t fc, uint32_t cn, uint8_t *guardBits) {
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];
// Get wiegand from FacilityCode 14bits, CardNumber 20bits
uint8_t wiegand[36];
memset(wiegand, 0x00, sizeof(wiegand));
num_to_bytebits(fc, 8, wiegand);
num_to_bytebits(cn, 26, wiegand + 8);
num_to_bytebits(fc, 14, wiegand);
num_to_bytebits(cn, 20, wiegand + 14);
// add wiegand parity bits (dest, source, len)
wiegand_add_parity(pre, wiegand, 34);
@ -351,28 +352,27 @@ int getGuardBits(uint8_t fmtlen, uint32_t fc, uint32_t cn, uint8_t *guardBits) {
rawbytes[3] = 0;
// add wiegand to rawbytes
for (i = 0; i < 4; ++i)
for (i = 0; i < 5; ++i)
rawbytes[i + 4] = bytebits_to_byte(pre + (i * 8), 8);
PrintAndLogEx(DEBUG, " WIE | %s\n", sprint_hex(rawbytes, sizeof(rawbytes)));
PrintAndLogEx(DEBUG, " WIE | %s", sprint_hex(rawbytes, sizeof(rawbytes)));
// XOR (only works on wiegand stuff)
for (i = 1; i < 12; ++i)
for (i = 1; i < sizeof(rawbytes); ++i)
rawbytes[i] ^= xorKey ;
PrintAndLogEx(DEBUG, " XOR | %s \n", sprint_hex(rawbytes, sizeof(rawbytes)));
PrintAndLogEx(DEBUG, " XOR | %s", sprint_hex(rawbytes, sizeof(rawbytes)));
// convert rawbytes to bits in pre
for (i = 0; i < 12; ++i)
for (i = 0; i < sizeof(rawbytes); ++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));
PrintAndLogEx(DEBUG, " Raw | %s", sprint_hex(rawbytes, sizeof(rawbytes)));
PrintAndLogEx(DEBUG, " Raw | %s", sprint_bin(pre, 96));
// 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);
// 12 bytes, 24 nibbles. 24+1 extra bites. 3bytes. ie 9bytes | 1byte xorkey, 8bytes rawdata (72bits, should be enough for a 40bit wiegand)
addParity(pre, guardBits + 6, 72, 5, 3);
// preamble
guardBits[0] = 1;