mirror of
https://github.com/Proxmark/proxmark3.git
synced 2024-09-20 14:56:21 +08:00
iclass.c: speeding up MAC calculation
This commit is contained in:
parent
17505ce2a7
commit
1477ba8a3c
|
@ -1146,7 +1146,7 @@ int doIClassSimulation(int simulationMode, uint8_t *reader_mac_buf) {
|
|||
memcpy(data_response, ToSend, ToSendMax);
|
||||
modulated_response = data_response;
|
||||
modulated_response_size = ToSendMax;
|
||||
response_delay = 0;//We need to hurry here...
|
||||
response_delay = 0; //We need to hurry here... (but maybe not too much... ??)
|
||||
//exitLoop = true;
|
||||
} else { //Not fullsim, we don't respond
|
||||
// We do not know what to answer, so lets keep quiet
|
||||
|
|
|
@ -60,15 +60,63 @@
|
|||
-- MHS 2015
|
||||
**/
|
||||
|
||||
/**
|
||||
|
||||
The runtime of opt_doTagMAC_2() with the MHS optimized version was 403 microseconds on Proxmark3.
|
||||
This was still to slow for some newer readers which didn't want to wait that long.
|
||||
|
||||
Further optimizations to speedup the MAC calculations:
|
||||
* Optimized opt_Tt logic
|
||||
* Look up table for opt_select
|
||||
* Removing many unnecessary bit maskings (& 0x1)
|
||||
* updating state in place instead of alternating use of a second state structure
|
||||
* remove the necessity to reverse bits of input and output bytes
|
||||
|
||||
opt_doTagMAC_2() now completes in 270 microseconds.
|
||||
|
||||
-- piwi 2019
|
||||
**/
|
||||
|
||||
#include "optimized_cipher.h"
|
||||
#include <stddef.h>
|
||||
#include <stdbool.h>
|
||||
#include <stdint.h>
|
||||
#include "string.h"
|
||||
|
||||
static const uint8_t opt_select_LUT[256] = {
|
||||
00, 03, 02, 01, 02, 03, 00, 01, 04, 07, 07, 04, 06, 07, 05, 04,
|
||||
01, 02, 03, 00, 02, 03, 00, 01, 05, 06, 06, 05, 06, 07, 05, 04,
|
||||
06, 05, 04, 07, 04, 05, 06, 07, 06, 05, 05, 06, 04, 05, 07, 06,
|
||||
07, 04, 05, 06, 04, 05, 06, 07, 07, 04, 04, 07, 04, 05, 07, 06,
|
||||
06, 05, 04, 07, 04, 05, 06, 07, 02, 01, 01, 02, 00, 01, 03, 02,
|
||||
03, 00, 01, 02, 00, 01, 02, 03, 07, 04, 04, 07, 04, 05, 07, 06,
|
||||
00, 03, 02, 01, 02, 03, 00, 01, 00, 03, 03, 00, 02, 03, 01, 00,
|
||||
05, 06, 07, 04, 06, 07, 04, 05, 05, 06, 06, 05, 06, 07, 05, 04,
|
||||
02, 01, 00, 03, 00, 01, 02, 03, 06, 05, 05, 06, 04, 05, 07, 06,
|
||||
03, 00, 01, 02, 00, 01, 02, 03, 07, 04, 04, 07, 04, 05, 07, 06,
|
||||
02, 01, 00, 03, 00, 01, 02, 03, 02, 01, 01, 02, 00, 01, 03, 02,
|
||||
03, 00, 01, 02, 00, 01, 02, 03, 03, 00, 00, 03, 00, 01, 03, 02,
|
||||
04, 07, 06, 05, 06, 07, 04, 05, 00, 03, 03, 00, 02, 03, 01, 00,
|
||||
01, 02, 03, 00, 02, 03, 00, 01, 05, 06, 06, 05, 06, 07, 05, 04,
|
||||
04, 07, 06, 05, 06, 07, 04, 05, 04, 07, 07, 04, 06, 07, 05, 04,
|
||||
01, 02, 03, 00, 02, 03, 00, 01, 01, 02, 02, 01, 02, 03, 01, 00
|
||||
};
|
||||
|
||||
#define opt_T(s) (0x1 & ((s->t >> 15) ^ (s->t >> 14)^ (s->t >> 10)^ (s->t >> 8)^ (s->t >> 5)^ (s->t >> 4)^ (s->t >> 1)^ s->t))
|
||||
|
||||
#define opt_B(s) (((s->b >> 6) ^ (s->b >> 5) ^ (s->b >> 4) ^ (s->b)) & 0x1)
|
||||
/********************** the table above has been generated with this code: ********
|
||||
#include "util.h"
|
||||
static void init_opt_select_LUT(void) {
|
||||
for (int r = 0; r < 256; r++) {
|
||||
uint8_t r_ls2 = r << 2;
|
||||
uint8_t r_and_ls2 = r & r_ls2;
|
||||
uint8_t r_or_ls2 = r | r_ls2;
|
||||
uint8_t z0 = (r_and_ls2 >> 5) ^ ((r & ~r_ls2) >> 4) ^ ( r_or_ls2 >> 3);
|
||||
uint8_t z1 = (r_or_ls2 >> 6) ^ ( r_or_ls2 >> 1) ^ (r >> 5) ^ r;
|
||||
uint8_t z2 = ((r & ~r_ls2) >> 4) ^ (r_and_ls2 >> 3) ^ r;
|
||||
opt_select_LUT[r] = (z0 & 4) | (z1 & 2) | (z2 & 1);
|
||||
}
|
||||
print_result("", opt_select_LUT, 256);
|
||||
}
|
||||
***********************************************************************************/
|
||||
|
||||
#define opt__select(x,y,r) (4 & (((r & (r << 2)) >> 5) ^ ((r & ~(r << 2)) >> 4) ^ ( (r | r << 2) >> 3)))\
|
||||
|(2 & (((r | r << 2) >> 6) ^ ( (r | r << 2) >> 1) ^ (r >> 5) ^ r ^ ((x^y) << 1)))\
|
||||
|
@ -78,9 +126,6 @@
|
|||
* Some background on the expression above can be found here...
|
||||
uint8_t xopt__select(bool x, bool y, uint8_t r)
|
||||
{
|
||||
uint8_t r_ls2 = r << 2;
|
||||
uint8_t r_and_ls2 = r & r_ls2;
|
||||
uint8_t r_or_ls2 = r | r_ls2;
|
||||
|
||||
//r: r0 r1 r2 r3 r4 r5 r6 r7
|
||||
//r_ls2: r2 r3 r4 r5 r6 r7 0 0
|
||||
|
@ -100,81 +145,95 @@ uint8_t xopt__select(bool x, bool y, uint8_t r)
|
|||
}
|
||||
*/
|
||||
|
||||
void opt_successor(const uint8_t *k, State *s, bool y, State *successor) {
|
||||
uint8_t Tt = 1 & opt_T(s);
|
||||
static void opt_successor(const uint8_t *k, State *s, uint8_t y) {
|
||||
// #define opt_T(s) (0x1 & ((s->t >> 15) ^ (s->t >> 14) ^ (s->t >> 10) ^ (s->t >> 8) ^ (s->t >> 5) ^ (s->t >> 4)^ (s->t >> 1) ^ s->t))
|
||||
// uint8_t Tt = opt_T(s);
|
||||
uint16_t Tt = s->t & 0xc533;
|
||||
Tt = Tt ^ (Tt >> 1);
|
||||
Tt = Tt ^ (Tt >> 4);
|
||||
Tt = Tt ^ (Tt >> 10);
|
||||
Tt = Tt ^ (Tt >> 8);
|
||||
|
||||
successor->t = (s->t >> 1);
|
||||
successor->t |= (Tt ^ (s->r >> 7 & 0x1) ^ (s->r >> 3 & 0x1)) << 15;
|
||||
s->t = (s->t >> 1);
|
||||
s->t |= (Tt ^ (s->r >> 7) ^ (s->r >> 3)) << 15;
|
||||
|
||||
successor->b = s->b >> 1;
|
||||
successor->b |= (opt_B(s) ^ (s->r & 0x1)) << 7;
|
||||
uint8_t opt_B = s->b;
|
||||
opt_B ^= s->b >> 6;
|
||||
opt_B ^= s->b >> 5;
|
||||
opt_B ^= s->b >> 4;
|
||||
|
||||
successor->r = (k[opt__select(Tt, y, s->r)] ^ successor->b) + s->l ;
|
||||
successor->l = successor->r + s->r;
|
||||
s->b = s->b >> 1;
|
||||
s->b |= (opt_B ^ s->r) << 7;
|
||||
|
||||
uint8_t opt_select = opt_select_LUT[s->r] & 0x04;
|
||||
opt_select |= (opt_select_LUT[s->r] ^ ((Tt ^ y) << 1)) & 0x02;
|
||||
opt_select |= (opt_select_LUT[s->r] ^ Tt) & 0x01;
|
||||
|
||||
uint8_t r = s->r;
|
||||
s->r = (k[opt_select] ^ s->b) + s->l ;
|
||||
s->l = s->r + r;
|
||||
}
|
||||
|
||||
void opt_suc(const uint8_t *k, State *s, uint8_t *in, uint8_t length, bool add32Zeroes) {
|
||||
State x2;
|
||||
static void opt_suc(const uint8_t *k, State *s, uint8_t *in, uint8_t length, bool add32Zeroes) {
|
||||
for (int i = 0; i < length; i++) {
|
||||
uint8_t head;
|
||||
head = 1 & (in[i] >> 7);
|
||||
opt_successor(k, s, head, &x2);
|
||||
head = in[i];
|
||||
opt_successor(k, s, head);
|
||||
|
||||
head = 1 & (in[i] >> 6);
|
||||
opt_successor(k, &x2, head, s);
|
||||
head >>= 1;
|
||||
opt_successor(k, s, head);
|
||||
|
||||
head = 1 & (in[i] >> 5);
|
||||
opt_successor(k, s, head, &x2);
|
||||
head >>= 1;
|
||||
opt_successor(k, s, head);
|
||||
|
||||
head = 1 & (in[i] >> 4);
|
||||
opt_successor(k, &x2, head, s);
|
||||
head >>= 1;
|
||||
opt_successor(k, s, head);
|
||||
|
||||
head = 1 & (in[i] >> 3);
|
||||
opt_successor(k, s, head, &x2);
|
||||
head >>= 1;
|
||||
opt_successor(k, s, head);
|
||||
|
||||
head = 1 & (in[i] >> 2);
|
||||
opt_successor(k, &x2, head, s);
|
||||
head >>= 1;
|
||||
opt_successor(k, s, head);
|
||||
|
||||
head = 1 & (in[i] >> 1);
|
||||
opt_successor(k, s, head, &x2);
|
||||
head >>= 1;
|
||||
opt_successor(k, s, head);
|
||||
|
||||
head = 1 & in[i];
|
||||
opt_successor(k, &x2, head, s);
|
||||
head >>= 1;
|
||||
opt_successor(k, s, head);
|
||||
}
|
||||
//For tag MAC, an additional 32 zeroes
|
||||
if (add32Zeroes) {
|
||||
for(int i = 0; i < 16; i++) {
|
||||
opt_successor(k, s, 0, &x2);
|
||||
opt_successor(k, &x2, 0, s);
|
||||
opt_successor(k, s, 0);
|
||||
opt_successor(k, s, 0);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
void opt_output(const uint8_t *k, State *s, uint8_t *buffer) {
|
||||
State temp = {0, 0, 0, 0};
|
||||
static void opt_output(const uint8_t *k, State *s, uint8_t *buffer) {
|
||||
for (uint8_t times = 0; times < 4; times++) {
|
||||
uint8_t bout = 0;
|
||||
bout |= (s->r & 0x4) << 5;
|
||||
opt_successor(k, s, 0, &temp);
|
||||
bout |= (temp.r & 0x4) << 4;
|
||||
opt_successor(k, &temp, 0, s);
|
||||
bout |= (s->r & 0x4) << 3;
|
||||
opt_successor(k, s, 0, &temp);
|
||||
bout |= (temp.r & 0x4) << 2;
|
||||
opt_successor(k, &temp, 0, s);
|
||||
bout |= (s->r & 0x4) << 1;
|
||||
opt_successor(k, s, 0, &temp);
|
||||
bout |= (temp.r & 0x4) ;
|
||||
opt_successor(k, &temp, 0, s);
|
||||
bout |= (s->r & 0x4) >> 2;
|
||||
opt_successor(k, s, 0);
|
||||
bout |= (s->r & 0x4) >> 1;
|
||||
opt_successor(k, s, 0, &temp);
|
||||
bout |= (temp.r & 0x4) >> 2;
|
||||
opt_successor(k, &temp, 0, s);
|
||||
opt_successor(k, s, 0);
|
||||
bout |= (s->r & 0x4);
|
||||
opt_successor(k, s, 0);
|
||||
bout |= (s->r & 0x4) << 1;
|
||||
opt_successor(k, s, 0);
|
||||
bout |= (s->r & 0x4) << 2;
|
||||
opt_successor(k, s, 0);
|
||||
bout |= (s->r & 0x4) << 3;
|
||||
opt_successor(k, s, 0);
|
||||
bout |= (s->r & 0x4) << 4;
|
||||
opt_successor(k, s, 0);
|
||||
bout |= (s->r & 0x4) << 5;
|
||||
opt_successor(k, s, 0);
|
||||
buffer[times] = bout;
|
||||
}
|
||||
}
|
||||
|
||||
void opt_MAC(uint8_t *k, uint8_t *input, uint8_t *out) {
|
||||
static void opt_MAC(uint8_t *k, uint8_t *input, uint8_t *out) {
|
||||
State _init = {
|
||||
((k[0] ^ 0x4c) + 0xEC) & 0xFF,// l
|
||||
((k[0] ^ 0x4c) + 0x21) & 0xFF,// r
|
||||
|
@ -187,43 +246,22 @@ void opt_MAC(uint8_t *k, uint8_t *input, uint8_t *out) {
|
|||
opt_output(k, &_init, out);
|
||||
}
|
||||
|
||||
uint8_t rev_byte(uint8_t b) {
|
||||
b = (b & 0xF0) >> 4 | (b & 0x0F) << 4;
|
||||
b = (b & 0xCC) >> 2 | (b & 0x33) << 2;
|
||||
b = (b & 0xAA) >> 1 | (b & 0x55) << 1;
|
||||
return b;
|
||||
}
|
||||
|
||||
void opt_reverse_arraybytecpy(uint8_t *dest, uint8_t *src, size_t len) {
|
||||
for (size_t i = 0; i < len; i++) {
|
||||
dest[i] = rev_byte(src[i]);
|
||||
}
|
||||
}
|
||||
|
||||
void opt_doReaderMAC(uint8_t *cc_nr_p, uint8_t *div_key_p, uint8_t mac[4]) {
|
||||
static uint8_t cc_nr[12];
|
||||
opt_reverse_arraybytecpy(cc_nr, cc_nr_p, 12);
|
||||
uint8_t dest[] = {0, 0, 0, 0, 0, 0, 0, 0};
|
||||
opt_MAC(div_key_p, cc_nr, dest);
|
||||
//The output MAC must also be reversed
|
||||
opt_reverse_arraybytecpy(mac, dest, 4);
|
||||
opt_MAC(div_key_p, cc_nr_p, dest);
|
||||
memcpy(mac, dest, 4);
|
||||
return;
|
||||
}
|
||||
|
||||
void opt_doTagMAC(uint8_t *cc_p, const uint8_t *div_key_p, uint8_t mac[4]) {
|
||||
static uint8_t cc_nr[8+4+4];
|
||||
opt_reverse_arraybytecpy(cc_nr, cc_p, 12);
|
||||
State _init = {
|
||||
((div_key_p[0] ^ 0x4c) + 0xEC) & 0xFF,// l
|
||||
((div_key_p[0] ^ 0x4c) + 0x21) & 0xFF,// r
|
||||
0x4c, // b
|
||||
0xE012 // t
|
||||
};
|
||||
opt_suc(div_key_p, &_init,cc_nr, 12, true);
|
||||
uint8_t dest[] = {0, 0, 0, 0};
|
||||
opt_output(div_key_p, &_init, dest);
|
||||
//The output MAC must also be reversed
|
||||
opt_reverse_arraybytecpy(mac, dest, 4);
|
||||
opt_suc(div_key_p, &_init, cc_p, 12, true);
|
||||
opt_output(div_key_p, &_init, mac);
|
||||
return;
|
||||
}
|
||||
|
||||
|
@ -236,15 +274,13 @@ void opt_doTagMAC(uint8_t *cc_p, const uint8_t *div_key_p, uint8_t mac[4]) {
|
|||
* @return the cipher state
|
||||
*/
|
||||
State opt_doTagMAC_1(uint8_t *cc_p, const uint8_t *div_key_p) {
|
||||
static uint8_t cc_nr[8];
|
||||
opt_reverse_arraybytecpy(cc_nr, cc_p, 8);
|
||||
State _init = {
|
||||
((div_key_p[0] ^ 0x4c) + 0xEC) & 0xFF,// l
|
||||
((div_key_p[0] ^ 0x4c) + 0x21) & 0xFF,// r
|
||||
0x4c, // b
|
||||
0xE012 // t
|
||||
};
|
||||
opt_suc(div_key_p, &_init, cc_nr, 8, false);
|
||||
opt_suc(div_key_p, &_init, cc_p, 8, false);
|
||||
return _init;
|
||||
}
|
||||
|
||||
|
@ -258,13 +294,7 @@ State opt_doTagMAC_1(uint8_t *cc_p, const uint8_t *div_key_p) {
|
|||
* @param div_key_p - the key to use
|
||||
*/
|
||||
void opt_doTagMAC_2(State _init, uint8_t *nr, uint8_t mac[4], const uint8_t *div_key_p) {
|
||||
static uint8_t _nr[4];
|
||||
opt_reverse_arraybytecpy(_nr, nr, 4);
|
||||
opt_suc(div_key_p, &_init, _nr, 4, true);
|
||||
//opt_suc(div_key_p, &_init,nr, 4, false);
|
||||
uint8_t dest[] = {0, 0, 0, 0};
|
||||
opt_output(div_key_p, &_init, dest);
|
||||
//The output MAC must also be reversed
|
||||
opt_reverse_arraybytecpy(mac, dest, 4);
|
||||
opt_suc(div_key_p, &_init, nr, 4, true);
|
||||
opt_output(div_key_p, &_init, mac);
|
||||
return;
|
||||
}
|
||||
|
|
Loading…
Reference in a new issue