RfidResearchGroup/proxmark3
1
1
Fork 0
mirror of https://github.com/RfidResearchGroup/proxmark3.git synced 2024-09-20 23:36:31 +08:00
Code Issues Packages Projects Releases Wiki Activity

Extract bitstream creation to function.

Browse source
This commit is contained in:
Angel 2023-04-15 22:25:20 -04:00
parent 0a66f809a6
commit ab460c4a22
1 changed files with 55 additions and 38 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

93
client/src/cmdlfparadox.c
View file

@ -46,6 +46,54 @@ static int CmdHelp(const char *Cmd);
// Paradox Prox demod - FSK2a RF/50 with preamble of 00001111 (then manchester encoded)
// print full Paradox Prox ID and some bit format details if found
// This function will calculate the bitstream for a paradox card and place the result in bs.
// It returns the calculated CRC from the fc and cn.
// CRC calculation by mwalker33
static uint8_t GetParadoxBits(const unsigned long fc, const unsigned long cn, unsigned int *bs){
uint8_t manchester[13] = { 0x00 }; // check size needed
uint32_t t1;
manchester[0] = 0x0F; // preamble
manchester[1] = 0x05; // Leading zeros - Note: from this byte on, is part of the CRC calculation
manchester[2] = 0x55; // Leading zeros its 4 bits out for the CRC, so we need to move
manchester[3] = 0x55; // Leading zeros back 4 bits once we have the crc (done below)
// add FC
t1 = manchesterEncode2Bytes(fc);
manchester[4] = (t1 >> 8) & 0xFF;
manchester[5] = t1 & 0xFF;
// add cn
t1 = manchesterEncode2Bytes(cn);
manchester[6] = (t1 >> 24) & 0xFF;
manchester[7] = (t1 >> 16) & 0xFF;
manchester[8] = (t1 >> 8) & 0xFF;
manchester[9] = t1 & 0xFF;
uint8_t crc = (CRC8Maxim(manchester + 1, 9) ^ 0x6) & 0xFF;
// add crc
t1 = manchesterEncode2Bytes(crc);
manchester[10] = (t1 >> 8) & 0xFF;
manchester[11] = t1 & 0xFF;
// move left 4 bits left 4 bits - Now that we have the CRC we need to re-align the data.
for (int i = 1; i < 12; i++)
manchester[i] = (manchester[i] << 4) + (manchester[i + 1] >> 4);
// Add trailing 1010 (11)
manchester[11] |= (1 << 3);
manchester[11] |= (1 << 1);
// move into tag blocks
for (int i = 0; i < 12; i++)
bs[1 + (i / 4)] += (manchester[i] << (8 * (3 - i % 4)));
return crc;
}
int demodParadox(bool verbose) {
(void) verbose; // unused so far
//raw fsk demod no manchester decoding no start bit finding just get binary from wave
@ -132,6 +180,12 @@ int demodParadox(bool verbose) {
uint32_t rawHi = bytebits_to_byte(bits + idx + 32, 32);
uint32_t rawHi2 = bytebits_to_byte(bits + idx, 32);
uint32_t blocks[4] = {0};
uint8_t crc = GetParadoxBits(fc,cardnum,blocks);
if(chksum != crc)
PrintAndLogEx(ERR,"CRC Error! Calculated CRC is " _GREEN_("%d") " but card CRC is " _RED_("%d") ".",crc,chksum);
PrintAndLogEx(INFO, "Paradox - ID: " _GREEN_("%x%08x") " FC: " _GREEN_("%d") " Card: " _GREEN_("%d") ", Checksum: %02x, Raw: %08x%08x%08x",
hi >> 10,
(hi & 0x3) << 26 | (lo >> 10),
@ -245,44 +299,7 @@ static int CmdParadoxClone(const char *Cmd) {
blocks[i] = bytes_to_num(raw + ((i - 1) * 4), sizeof(uint32_t));
}
} else {
uint8_t manchester[13] = { 0x00 }; // check size needed
uint32_t t1;
manchester[0] = 0x0F; // preamble
manchester[1] = 0x05; // Leading zeros - Note: from this byte on, is part of the CRC calculation
manchester[2] = 0x55; // Leading zeros its 4 bits out for the CRC, so we need too move
manchester[3] = 0x55; // Leading zeros back 4 bits once we have the crc (done below)
// add FC
t1 = manchesterEncode2Bytes(fc);
manchester[4] = (t1 >> 8) & 0xFF;
manchester[5] = t1 & 0xFF;
// add cn
t1 = manchesterEncode2Bytes(cn);
manchester[6] = (t1 >> 24) & 0xFF;
manchester[7] = (t1 >> 16) & 0xFF;
manchester[8] = (t1 >> 8) & 0xFF;
manchester[9] = t1 & 0xFF;
uint8_t crc = (CRC8Maxim(manchester + 1, 9) ^ 0x6) & 0xFF;
// add crc
t1 = manchesterEncode2Bytes(crc);
manchester[10] = (t1 >> 8) & 0xFF;
manchester[11] = t1 & 0xFF;
// move left 4 bits left 4 bits - Now that we have the CRC we need to re-align the data.
for (int i = 1; i < 12; i++)
manchester[i] = (manchester[i] << 4) + (manchester[i + 1] >> 4);
// Add trailing 1010 (11)
manchester[11] |= (1 << 3);
manchester[11] |= (1 << 1);
// move into tag blocks
for (int i = 0; i < 12; i++)
blocks[1 + (i / 4)] += (manchester[i] << (8 * (3 - i % 4)));
GetParadoxBits(fc, cn, blocks);
}
// Paradox - FSK2a, data rate 50, 3 data blocks