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In my attempts to make the LEGIC code better, its not working now. Timings if off.

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CHG: switching to US clock.
CHG: better trace annotation for legic
CHG: Legic prng can now give a x bits in once.
This commit is contained in:
iceman1001 2016-09-09 11:56:20 +02:00
commit ad5bc8cc8c
9 changed files with 318 additions and 235 deletions
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32
common/legic_prng.c
View file

@ -7,22 +7,35 @@
//-----------------------------------------------------------------------------
#include "legic_prng.h"
// a is 7bit
// b is
// c is a counter
struct lfsr {
uint8_t a;
uint8_t b;
uint32_t c;
} lfsr;
void legic_prng_init(uint8_t init) {
lfsr.a = init;
// Normal init is set following variables with a random value IV
// a == iv
// b == iv << 1 | 1
// * someone mentioned iv must be ODD.
// Hack:
// Now we have a special case with iv == 0
// it sets b to 0 aswell to make sure we get a all zero keystream out
// which is used in the initialisation phase sending the IV
//
void legic_prng_init(uint8_t iv) {
lfsr.a = iv;
lfsr.b = 0; // hack to get a always 0 keystream
lfsr.c = 0;
if(init)
lfsr.b = (init << 1) | 1;
if(iv)
lfsr.b = (iv << 1) | 1;
}
void legic_prng_forward(int count) {
if (count == 0) return;
lfsr.c += count;
while(count--) {
// According: http://www.proxmark.org/forum/viewtopic.php?pid=5437#p5437
@ -38,4 +51,13 @@ uint32_t legic_prng_count() {
uint8_t legic_prng_get_bit() {
uint8_t idx = 7 - ( (lfsr.a & 4) | (lfsr.a >> 2 & 2) | (lfsr.a >> 4 & 1) );
return lfsr.b >> idx & 1;
}
uint32_t legic_prng_get_bits(uint8_t len){
uint32_t a = 0;
for(uint8_t i = 0; i < len; ++i) {
a |= legic_prng_get_bit() << i;
legic_prng_forward(1);
}
return a;
}

7
common/protocols.h
View file

@ -326,9 +326,10 @@ ISO 7816-4 Basic interindustry commands. For command APDU's.
#define MFDES_AUTHENTICATION_FRAME 0xAF
// LEGIC Commands
#define LEGIC_HSK 0x39
#define LEGIC_READ 0x01
#define LEGIC_WRITE 0x00
#define LEGIC_HSK_22 0x19
#define LEGIC_HSK_256 0x39
#define LEGIC_READ 0x01
#define LEGIC_WRITE 0x00
void printIclassDumpInfo(uint8_t* iclass_dump);
void getMemConfig(uint8_t mem_cfg, uint8_t chip_cfg, uint8_t *max_blk, uint8_t *app_areas, uint8_t *kb);