github/RRG-Proxmark3
1
0
Fork 0
mirror of https://github.com/RfidResearchGroup/proxmark3.git synced 2025-07-08 05:51:08 -07:00
Code Issues Projects Releases Packages Wiki Activity Actions 4

lets see if this still detects sentinels

Browse source
This commit is contained in:
iceman1001 2022-08-21 09:40:36 +02:00
parent 28449aa580
commit 38a664f00c
1 changed files with 7 additions and 11 deletions
Download patch file Download diff file Expand all files Collapse all files

18
client/src/wiegand_formatutils.c
View file

@ -131,24 +131,17 @@ bool set_nonlinear_field(wiegand_message_t *data, uint64_t value, uint8_t numBit
static uint8_t get_length_from_header(wiegand_message_t *data) {
/**
* detect if message has "preamble" / "sentinel bit"
*
* Right now we just calculate the highest bit set
* 37 bit formats is hard to detect since it doesnt have a sentinel bit
*/
uint8_t len = 0;
uint32_t hfmt = 0; // for calculating card length
if ((data->Top & 0x000FFFFF) > 0) { // > 64 bits
hfmt = data->Top & 0x000FFFFF;
len = 64;
} else if ((data->Mid & 0xFFFFFFC0) > 0) { // < 63-38 bits
hfmt = data->Mid & 0xFFFFFFC0;
len = 32;
} else if (data->Mid && (data->Mid & 0x00000020) == 0) { // 37 bits;
hfmt = 0;
len = 37;
} else if ((data->Mid & 0x0000001F) > 0) { // 36-32 bits
hfmt = data->Mid & 0x0000001F;
} else if (data->Mid > 0) { // < 63-32 bits
hfmt = data->Mid;
len = 32;
} else {
hfmt = data->Bot;
@ -159,8 +152,11 @@ static uint8_t get_length_from_header(wiegand_message_t *data) {
hfmt >>= 1;
len++;
}
// everything less than 26 bits found, assume 26 bits
if (len < 26)
len = 26;
return len;
}