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CHG: using bitsend to determind the legic annotation in "hf list legic" makes false positives much less.

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This commit is contained in:
iceman1001 2016-09-26 12:26:37 +02:00
commit faabfafe30
2 changed files with 64 additions and 53 deletions
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74
armsrc/legicrf.c
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@ -116,7 +116,7 @@ uint32_t sendFrameStop = 0;
#define LEGIC_CARD_MEMSIZE 1024
static uint8_t* cardmem;
static void frame_append_bit(struct legic_frame * const f, int bit) {
static void frame_append_bit(struct legic_frame * const f, uint8_t bit) {
// Overflow, won't happen
if (f->bits >= 31) return;
@ -225,7 +225,7 @@ void frame_sendAsReader(uint32_t data, uint8_t bits){
uint32_t starttime = GET_TICKS, send = 0;
uint16_t mask = 1;
uint8_t prng1 = legic_prng_count() ;
uint8_t prngstart = legic_prng_count() ;
// xor lsfr onto data.
send = data ^ legic_prng_get_bits(bits);
@ -243,10 +243,12 @@ void frame_sendAsReader(uint32_t data, uint8_t bits){
sendFrameStop = GET_TICKS;
uint8_t cmdbytes[] = {
bits,
BYTEx(data, 0),
BYTEx(data, 1),
bits,
prng1,
0x00,
0x00,
prngstart,
legic_prng_count()
};
LogTrace(cmdbytes, sizeof(cmdbytes), starttime, sendFrameStop, NULL, TRUE);
@ -287,21 +289,29 @@ static void frame_receiveAsReader(struct legic_frame * const f, uint8_t bits) {
AT91C_BASE_PIOA->PIO_ODR = GPIO_SSC_DIN;
AT91C_BASE_PIOA->PIO_PER = GPIO_SSC_DIN;
// calibrate the prng.
// calibrate the prng.
//
legic_prng_forward(2);
// precompute the cipher
uint8_t prng_before = legic_prng_count() ;
uint8_t prngstart = legic_prng_count() ;
lsfr = legic_prng_get_bits(bits);
data = lsfr;
data = lsfr = legic_prng_get_bits(bits);
//FIXED time between sending frame and now listening frame. 330us
//WaitTicks( TAG_FRAME_WAIT - (GET_TICKS - sendFrameStop ) );
WaitTicks( 495 );
// 387 = 0x19 0001 1001
// 480 = 0x19
// 500 = 0x1C 0001 1100
uint32_t starttime = GET_TICKS;
//uint16_t mywait = TAG_FRAME_WAIT - (starttime - sendFrameStop);
uint16_t mywait = 495 - (starttime - sendFrameStop);
if ( bits == 6)
WaitTicks( 495 - 9 );
else {
//Dbprintf("WAIT %d", mywait );
WaitTicks( mywait );
}
next_bit_at = GET_TICKS + TAG_BIT_PERIOD;
while ( i-- ){
@ -325,7 +335,8 @@ static void frame_receiveAsReader(struct legic_frame * const f, uint8_t bits) {
next_bit_at += TAG_BIT_PERIOD;
// We expect 42 edges == ONE
if(edges > 20 && edges < 64)
//if (edges > 20 && edges < 64)
if ( edges > 20 )
data ^= the_bit;
the_bit <<= 1;
@ -334,22 +345,17 @@ static void frame_receiveAsReader(struct legic_frame * const f, uint8_t bits) {
// output
f->data = data;
f->bits = bits;
// log
sendFrameStop = GET_TICKS;
uint8_t cmdbytes[] = {
uint8_t cmdbytes[] = {
bits,
BYTEx(data,0),
BYTEx(data,1),
bits,
BYTEx(lsfr,0),
BYTEx(lsfr,1),
BYTEx(data, 0) ^ BYTEx(lsfr,0),
BYTEx(data, 1) ^ BYTEx(lsfr,1),
prng_before,
prngstart,
legic_prng_count()
};
LogTrace(cmdbytes, sizeof(cmdbytes), starttime, sendFrameStop, NULL, FALSE);
LogTrace(cmdbytes, sizeof(cmdbytes), starttime, GET_TICKS, NULL, FALSE);
}
// Setup pm3 as a Legic Reader
@ -438,8 +444,8 @@ int legic_read_byte(int byte_index, int cmd_sz) {
// 460 | 690
// 258 | 387
// 244 | 366
WaitTicks(366);
legic_prng_forward(3); // 460 / 100 = 4.6 iterations
WaitTicks(387);
legic_prng_forward(4); // 460 / 100 = 4.6 iterations
uint8_t byte = 0, crc = 0, calcCrc = 0;
uint32_t cmd = (byte_index << 1) | LEGIC_READ;
@ -455,9 +461,6 @@ int legic_read_byte(int byte_index, int cmd_sz) {
Dbprintf("!!! crc mismatch: expected %x but got %x !!!", calcCrc, crc);
return -1;
}
// legic_prng_forward(2); // 460 / 100 = 4.6 iterations
return byte;
}
@ -534,18 +537,13 @@ int legic_write_byte(uint8_t byte, uint16_t addr, uint8_t addr_sz) {
int LegicRfReader(int offset, int bytes, int iv) {
uint16_t byte_index = 0;
uint8_t cmd_sz = 0;
int card_sz = 0;
uint8_t isOK = 1;
if ( MF_DBGLEVEL >= 2)
Dbprintf("setting up legic card, IV = 0x%02x", iv);
uint8_t cmd_sz = 0, isOK = 1;
int card_sz = 0;
LegicCommonInit();
uint32_t tag_type = setup_phase_reader(iv);
//we lose to mutch time with dprintf
switch_off_tag_rwd();
switch(tag_type) {
@ -584,16 +582,16 @@ int LegicRfReader(int offset, int bytes, int iv) {
int r = legic_read_byte(byte_index + offset, cmd_sz);
if (r == -1 || BUTTON_PRESS()) {
if ( MF_DBGLEVEL >= 2) DbpString("operation aborted");
if ( MF_DBGLEVEL >= 3) DbpString("operation aborted");
isOK = 0;
goto OUT;
}
cardmem[++byte_index] = r;
//byte_index++;
WDT_HIT();
}
OUT:
WDT_HIT();
switch_off_tag_rwd();
LEDsoff();
uint8_t len = (bytes & 0x3FF);