/*****************************************************************************
* WARNING
*
- * THIS CODE IS CREATED FOR EXPERIMENTATION AND EDUCATIONAL USE ONLY.
- *
- * USAGE OF THIS CODE IN OTHER WAYS MAY INFRINGE UPON THE INTELLECTUAL
- * PROPERTY OF OTHER PARTIES, SUCH AS INSIDE SECURE AND HID GLOBAL,
- * AND MAY EXPOSE YOU TO AN INFRINGEMENT ACTION FROM THOSE PARTIES.
- *
- * THIS CODE SHOULD NEVER BE USED TO INFRINGE PATENTS OR INTELLECTUAL PROPERTY RIGHTS.
+ * THIS CODE IS CREATED FOR EXPERIMENTATION AND EDUCATIONAL USE ONLY.
+ *
+ * USAGE OF THIS CODE IN OTHER WAYS MAY INFRINGE UPON THE INTELLECTUAL
+ * PROPERTY OF OTHER PARTIES, SUCH AS INSIDE SECURE AND HID GLOBAL,
+ * AND MAY EXPOSE YOU TO AN INFRINGEMENT ACTION FROM THOSE PARTIES.
+ *
+ * THIS CODE SHOULD NEVER BE USED TO INFRINGE PATENTS OR INTELLECTUAL PROPERTY RIGHTS.
*
*****************************************************************************
*
*
* This is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as published
- * by the Free Software Foundation.
+ * by the Free Software Foundation, or, at your option, any later version.
*
* This file is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
*
* You should have received a copy of the GNU General Public License
* along with loclass. If not, see <http://www.gnu.org/licenses/>.
- *
- *
- *
+ *
+ *
+ *
****************************************************************************/
/**
-- MHS 2015
**/
-#include "optimized_cipher.h"
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include <stdbool.h>
-#include <stdint.h>
-#include <time.h>
-
/**
-* Definition 1 (Cipher state). A cipher state of iClass s is an element of F 40/2
-* consisting of the following four components:
-* 1. the left register l = (l 0 . . . l 7 ) ∈ F 8/2 ;
-* 2. the right register r = (r 0 . . . r 7 ) ∈ F 8/2 ;
-* 3. the top register t = (t 0 . . . t 15 ) ∈ F 16/2 .
-* 4. the bottom register b = (b 0 . . . b 7 ) ∈ F 8/2 .
-**/
-typedef struct {
- uint8_t l;
- uint8_t r;
- uint8_t b;
- uint16_t t;
-} State;
+ 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.
-#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))
+ 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.
-#define opt_B(s) (((s->b >> 6) ^ (s->b >> 5) ^ (s->b >> 4) ^ (s->b)) & 0x1)
+ -- 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
+};
+
+/********************** 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)))\
* 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
// z0
// z1
-// uint8_t z0 = (r0 & r2) ^ (r1 & ~r3) ^ (r2 | r4); // <-- original
+// uint8_t z0 = (r0 & r2) ^ (r1 & ~r3) ^ (r2 | r4); // <-- original
uint8_t z0 = (r_and_ls2 >> 5) ^ ((r & ~r_ls2) >> 4) ^ ( r_or_ls2 >> 3);
-// uint8_t z1 = (r0 | r2) ^ ( r5 | r7) ^ r1 ^ r6 ^ x ^ y; // <-- original
+// uint8_t z1 = (r0 | r2) ^ ( r5 | r7) ^ r1 ^ r6 ^ x ^ y; // <-- original
uint8_t z1 = (r_or_ls2 >> 6) ^ ( r_or_ls2 >> 1) ^ (r >> 5) ^ r ^ ((x^y) << 1);
-// uint8_t z2 = (r3 & ~r5) ^ (r4 & r6 ) ^ r7 ^ x; // <-- original
+// uint8_t z2 = (r3 & ~r5) ^ (r4 & r6 ) ^ r7 ^ x; // <-- original
uint8_t z2 = ((r & ~r_ls2) >> 4) ^ (r_and_ls2 >> 3) ^ r ^ x;
return (z0 & 4) | (z1 & 2) | (z2 & 1);
}
*/
-void opt_successor(uint8_t* k, State *s, bool y, State* successor)
-{
-
- uint8_t Tt = 1 & opt_T(s);
-
- successor->t = (s->t >> 1);
- successor->t |= (Tt ^ (s->r >> 7 & 0x1) ^ (s->r >> 3 & 0x1)) << 15;
-
- successor->b = s->b >> 1;
- successor->b |= (opt_B(s) ^ (s->r & 0x1)) << 7;
-
- successor->r = (k[opt__select(Tt,y,s->r)] ^ successor->b) + s->l ;
- successor->l = successor->r+s->r;
-
+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);
+
+ s->t = (s->t >> 1);
+ s->t |= (Tt ^ (s->r >> 7) ^ (s->r >> 3)) << 15;
+
+ uint8_t opt_B = s->b;
+ opt_B ^= s->b >> 6;
+ opt_B ^= s->b >> 5;
+ opt_B ^= s->b >> 4;
+
+ 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(uint8_t* k,State* s, uint8_t *in)
-{
- State x2;
- int i;
- uint8_t head = 0;
- for(i =0 ; i < 12 ; i++)
- {
- head = 1 & (in[i] >> 7);
- opt_successor(k,s,head,&x2);
-
- head = 1 & (in[i] >> 6);
- opt_successor(k,&x2,head,s);
+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 = in[i];
+ 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);
+ 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);
+ opt_successor(k, s, 0);
+ }
}
-
}
-void opt_output(uint8_t* k,State* s, uint8_t *buffer)
-{
- uint8_t times = 0;
- uint8_t bout = 0;
- State temp = {0,0,0,0};
- for( ; times < 4 ; times++)
- {
- 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);
+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) >> 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
- 0x4c, // b
- 0xE012 // t
- };
+ ((k[0] ^ 0x4c) + 0xEC) & 0xFF,// l
+ ((k[0] ^ 0x4c) + 0x21) & 0xFF,// r
+ 0x4c, // b
+ 0xE012 // t
+ };
- opt_suc(k,&_init,input);
+ opt_suc(k, &_init, input, 12, false);
//printf("\noutp ");
- opt_output(k,&_init, 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_doReaderMAC(uint8_t *cc_nr_p, uint8_t *div_key_p, uint8_t mac[4]) {
+ uint8_t dest[] = {0, 0, 0, 0, 0, 0, 0, 0};
+ opt_MAC(div_key_p, cc_nr_p, dest);
+ memcpy(mac, dest, 4);
+ return;
}
-void opt_reverse_arraybytecpy(uint8_t* dest, uint8_t *src, size_t len)
-{
- uint8_t i;
- for( i =0; i< len ; i++)
- dest[i] = rev_byte(src[i]);
+
+void opt_doTagMAC(uint8_t *cc_p, const uint8_t *div_key_p, uint8_t mac[4]) {
+ 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_p, 12, true);
+ opt_output(div_key_p, &_init, mac);
+ return;
}
-void opt_doMAC(uint8_t *cc_nr_p, uint8_t *div_key_p, uint8_t mac[4])
-{
- static uint8_t cc_nr[13];
- static uint8_t div_key[8];
-
- opt_reverse_arraybytecpy(cc_nr, cc_nr_p,12);
- memcpy(div_key,div_key_p,8);
- uint8_t dest []= {0,0,0,0,0,0,0,0};
- opt_MAC(div_key,cc_nr, dest);
- //The output MAC must also be reversed
- opt_reverse_arraybytecpy(mac, dest,12);
+/**
+ * The tag MAC can be divided (both can, but no point in dividing the reader mac) into
+ * two functions, since the first 8 bytes are known, we can pre-calculate the state
+ * reached after feeding CC to the cipher.
+ * @param cc_p
+ * @param div_key_p
+ * @return the cipher state
+ */
+State opt_doTagMAC_1(uint8_t *cc_p, const uint8_t *div_key_p) {
+ 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_p, 8, false);
+ return _init;
+}
+
+/**
+ * The second part of the tag MAC calculation, since the CC is already calculated into the state,
+ * this function is fed only the NR, and internally feeds the remaining 32 0-bits to generate the tag
+ * MAC response.
+ * @param _init - precalculated cipher state
+ * @param nr - the reader challenge
+ * @param mac - where to store the MAC
+ * @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) {
+ opt_suc(div_key_p, &_init, nr, 4, true);
+ opt_output(div_key_p, &_init, mac);
return;
}
projects / proxmark3-svn / blobdiff