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Namespace loclass library (#1379)
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* Namespace loclass library
* Lib: const for immutable variables and bss cleanup

Co-authored-by: あく <[email protected]>
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@bettse @skotopes
bettse and skotopes authored Jul 8, 2022
1 parent 6b3625f commit f46ae5a
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4 changes: 2 additions & 2 deletions applications/picopass/picopass_worker.c
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Original file line number Diff line number Diff line change
Expand Up @@ -198,8 +198,8 @@ ReturnCode picopass_read_card(ApplicationArea* AA1) {
}
memcpy(ccnr, rcRes.CCNR, sizeof(rcRes.CCNR)); // last 4 bytes left 0

diversifyKey(selRes.CSN, picopass_iclass_key, div_key);
opt_doReaderMAC(ccnr, div_key, mac);
loclass_diversifyKey(selRes.CSN, picopass_iclass_key, div_key);
loclass_opt_doReaderMAC(ccnr, div_key, mac);

err = rfalPicoPassPollerCheck(mac, &chkRes);
if(err != ERR_NONE) {
Expand Down
143 changes: 59 additions & 84 deletions lib/loclass/optimized_cipher.c
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Original file line number Diff line number Diff line change
Expand Up @@ -81,7 +81,7 @@
#include "optimized_ikeys.h"
#include "optimized_cipherutils.h"

static const uint8_t opt_select_LUT[256] = {
static const uint8_t loclass_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,
Expand Down Expand Up @@ -110,42 +110,18 @@ static void init_opt_select_LUT(void) {
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);
loclass_opt_select_LUT[r] = (z0 & 4) | (z1 & 2) | (z2 & 1);
}
print_result("", opt_select_LUT, 256);
print_result("", loclass_opt_select_LUT, 256);
}
***********************************************************************************/

#define opt__select(x,y,r) (4 & (((r & (r << 2)) >> 5) ^ ((r & ~(r << 2)) >> 4) ^ ( (r | r << 2) >> 3)))\
#define loclass_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)))\
|(1 & (((r & ~(r << 2)) >> 4) ^ ((r & (r << 2)) >> 3) ^ r ^ x))

/*
* Some background on the expression above can be found here...
uint8_t xopt__select(bool x, bool y, uint8_t r)
{
//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 = (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 = (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 = ((r & ~r_ls2) >> 4) ^ (r_and_ls2 >> 3) ^ r ^ x;
return (z0 & 4) | (z1 & 2) | (z2 & 1);
}
*/

static void opt_successor(const uint8_t *k, State_t *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);
static void loclass_opt_successor(const uint8_t *k, LoclassState_t *s, uint8_t y) {
uint16_t Tt = s->t & 0xc533;
Tt = Tt ^ (Tt >> 1);
Tt = Tt ^ (Tt >> 4);
Expand All @@ -163,125 +139,125 @@ static void opt_successor(const uint8_t *k, State_t *s, uint8_t y) {
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 opt_select = loclass_opt_select_LUT[s->r] & 0x04;
opt_select |= (loclass_opt_select_LUT[s->r] ^ ((Tt ^ y) << 1)) & 0x02;
opt_select |= (loclass_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;
}

static void opt_suc(const uint8_t *k, State_t *s, const uint8_t *in, uint8_t length, bool add32Zeroes) {
static void loclass_opt_suc(const uint8_t *k, LoclassState_t *s, const 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);
loclass_opt_successor(k, s, head);

head >>= 1;
opt_successor(k, s, head);
loclass_opt_successor(k, s, head);

head >>= 1;
opt_successor(k, s, head);
loclass_opt_successor(k, s, head);

head >>= 1;
opt_successor(k, s, head);
loclass_opt_successor(k, s, head);

head >>= 1;
opt_successor(k, s, head);
loclass_opt_successor(k, s, head);

head >>= 1;
opt_successor(k, s, head);
loclass_opt_successor(k, s, head);

head >>= 1;
opt_successor(k, s, head);
loclass_opt_successor(k, s, head);

head >>= 1;
opt_successor(k, s, head);
loclass_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);
loclass_opt_successor(k, s, 0);
loclass_opt_successor(k, s, 0);
}
}
}

static void opt_output(const uint8_t *k, State_t *s, uint8_t *buffer) {
static void loclass_opt_output(const uint8_t *k, LoclassState_t *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);
loclass_opt_successor(k, s, 0);
bout |= (s->r & 0x4) >> 1;
opt_successor(k, s, 0);
loclass_opt_successor(k, s, 0);
bout |= (s->r & 0x4);
opt_successor(k, s, 0);
loclass_opt_successor(k, s, 0);
bout |= (s->r & 0x4) << 1;
opt_successor(k, s, 0);
loclass_opt_successor(k, s, 0);
bout |= (s->r & 0x4) << 2;
opt_successor(k, s, 0);
loclass_opt_successor(k, s, 0);
bout |= (s->r & 0x4) << 3;
opt_successor(k, s, 0);
loclass_opt_successor(k, s, 0);
bout |= (s->r & 0x4) << 4;
opt_successor(k, s, 0);
loclass_opt_successor(k, s, 0);
bout |= (s->r & 0x4) << 5;
opt_successor(k, s, 0);
loclass_opt_successor(k, s, 0);
buffer[times] = bout;
}
}

static void opt_MAC(uint8_t *k, uint8_t *input, uint8_t *out) {
State_t _init = {
static void loclass_opt_MAC(uint8_t *k, uint8_t *input, uint8_t *out) {
LoclassState_t _init = {
((k[0] ^ 0x4c) + 0xEC) & 0xFF,// l
((k[0] ^ 0x4c) + 0x21) & 0xFF,// r
0x4c, // b
0xE012 // t
};

opt_suc(k, &_init, input, 12, false);
opt_output(k, &_init, out);
loclass_opt_suc(k, &_init, input, 12, false);
loclass_opt_output(k, &_init, out);
}

static void opt_MAC_N(uint8_t *k, uint8_t *input, uint8_t in_size, uint8_t *out) {
State_t _init = {
static void loclass_opt_MAC_N(uint8_t *k, uint8_t *input, uint8_t in_size, uint8_t *out) {
LoclassState_t _init = {
((k[0] ^ 0x4c) + 0xEC) & 0xFF,// l
((k[0] ^ 0x4c) + 0x21) & 0xFF,// r
0x4c, // b
0xE012 // t
};

opt_suc(k, &_init, input, in_size, false);
opt_output(k, &_init, out);
loclass_opt_suc(k, &_init, input, in_size, false);
loclass_opt_output(k, &_init, out);
}

void opt_doReaderMAC(uint8_t *cc_nr_p, uint8_t *div_key_p, uint8_t mac[4]) {
void loclass_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);
loclass_opt_MAC(div_key_p, cc_nr_p, dest);
memcpy(mac, dest, 4);
}

void opt_doReaderMAC_2(State_t _init, uint8_t *nr, uint8_t mac[4], const uint8_t *div_key_p) {
opt_suc(div_key_p, &_init, nr, 4, false);
opt_output(div_key_p, &_init, mac);
void loclass_opt_doReaderMAC_2(LoclassState_t _init, uint8_t *nr, uint8_t mac[4], const uint8_t *div_key_p) {
loclass_opt_suc(div_key_p, &_init, nr, 4, false);
loclass_opt_output(div_key_p, &_init, mac);
}


void doMAC_N(uint8_t *in_p, uint8_t in_size, uint8_t *div_key_p, uint8_t mac[4]) {
void loclass_doMAC_N(uint8_t *in_p, uint8_t in_size, uint8_t *div_key_p, uint8_t mac[4]) {
uint8_t dest [] = {0, 0, 0, 0, 0, 0, 0, 0};
opt_MAC_N(div_key_p, in_p, in_size, dest);
loclass_opt_MAC_N(div_key_p, in_p, in_size, dest);
memcpy(mac, dest, 4);
}

void opt_doTagMAC(uint8_t *cc_p, const uint8_t *div_key_p, uint8_t mac[4]) {
State_t _init = {
void loclass_opt_doTagMAC(uint8_t *cc_p, const uint8_t *div_key_p, uint8_t mac[4]) {
LoclassState_t _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);
loclass_opt_suc(div_key_p, &_init, cc_p, 12, true);
loclass_opt_output(div_key_p, &_init, mac);
}

/**
Expand All @@ -292,14 +268,14 @@ void opt_doTagMAC(uint8_t *cc_p, const uint8_t *div_key_p, uint8_t mac[4]) {
* @param div_key_p
* @return the cipher state
*/
State_t opt_doTagMAC_1(uint8_t *cc_p, const uint8_t *div_key_p) {
State_t _init = {
LoclassState_t loclass_opt_doTagMAC_1(uint8_t *cc_p, const uint8_t *div_key_p) {
LoclassState_t _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);
loclass_opt_suc(div_key_p, &_init, cc_p, 8, false);
return _init;
}

Expand All @@ -312,27 +288,26 @@ State_t opt_doTagMAC_1(uint8_t *cc_p, const uint8_t *div_key_p) {
* @param mac - where to store the MAC
* @param div_key_p - the key to use
*/
void opt_doTagMAC_2(State_t _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);
void loclass_opt_doTagMAC_2(LoclassState_t _init, uint8_t *nr, uint8_t mac[4], const uint8_t *div_key_p) {
loclass_opt_suc(div_key_p, &_init, nr, 4, true);
loclass_opt_output(div_key_p, &_init, mac);
}


void iclass_calc_div_key(uint8_t *csn, uint8_t *key, uint8_t *div_key, bool elite) {
void loclass_iclass_calc_div_key(uint8_t *csn, uint8_t *key, uint8_t *div_key, bool elite) {
if (elite) {
uint8_t keytable[128] = {0};
uint8_t key_index[8] = {0};
uint8_t key_sel[8] = { 0 };
uint8_t key_sel_p[8] = { 0 };
hash2(key, keytable);
hash1(csn, key_index);
loclass_hash2(key, keytable);
loclass_hash1(csn, key_index);
for (uint8_t i = 0; i < 8 ; i++)
key_sel[i] = keytable[key_index[i]];

//Permute from iclass format to standard format
permutekey_rev(key_sel, key_sel_p);
diversifyKey(csn, key_sel_p, div_key);
loclass_permutekey_rev(key_sel, key_sel_p);
loclass_diversifyKey(csn, key_sel_p, div_key);
} else {
diversifyKey(csn, key, div_key);
loclass_diversifyKey(csn, key, div_key);
}
}
16 changes: 8 additions & 8 deletions lib/loclass/optimized_cipher.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -52,18 +52,18 @@ typedef struct {
uint8_t r;
uint8_t b;
uint16_t t;
} State_t;
} LoclassState_t;

/** The reader MAC is MAC(key, CC * NR )
**/
void opt_doReaderMAC(uint8_t *cc_nr_p, uint8_t *div_key_p, uint8_t mac[4]);
void loclass_opt_doReaderMAC(uint8_t *cc_nr_p, uint8_t *div_key_p, uint8_t mac[4]);

void opt_doReaderMAC_2(State_t _init, uint8_t *nr, uint8_t mac[4], const uint8_t *div_key_p);
void loclass_opt_doReaderMAC_2(LoclassState_t _init, uint8_t *nr, uint8_t mac[4], const uint8_t *div_key_p);

/**
* The tag MAC is MAC(key, CC * NR * 32x0))
*/
void opt_doTagMAC(uint8_t *cc_p, const uint8_t *div_key_p, uint8_t mac[4]);
void loclass_opt_doTagMAC(uint8_t *cc_p, const uint8_t *div_key_p, uint8_t mac[4]);

/**
* The tag MAC can be divided (both can, but no point in dividing the reader mac) into
Expand All @@ -73,7 +73,7 @@ void opt_doTagMAC(uint8_t *cc_p, const uint8_t *div_key_p, uint8_t mac[4]);
* @param div_key_p
* @return the cipher state
*/
State_t opt_doTagMAC_1(uint8_t *cc_p, const uint8_t *div_key_p);
LoclassState_t loclass_opt_doTagMAC_1(uint8_t *cc_p, const uint8_t *div_key_p);
/**
* 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
Expand All @@ -83,8 +83,8 @@ State_t opt_doTagMAC_1(uint8_t *cc_p, const uint8_t *div_key_p);
* @param mac - where to store the MAC
* @param div_key_p - the key to use
*/
void opt_doTagMAC_2(State_t _init, uint8_t *nr, uint8_t mac[4], const uint8_t *div_key_p);
void loclass_opt_doTagMAC_2(LoclassState_t _init, uint8_t *nr, uint8_t mac[4], const uint8_t *div_key_p);

void doMAC_N(uint8_t *in_p, uint8_t in_size, uint8_t *div_key_p, uint8_t mac[4]);
void iclass_calc_div_key(uint8_t *csn, uint8_t *key, uint8_t *div_key, bool elite);
void loclass_doMAC_N(uint8_t *in_p, uint8_t in_size, uint8_t *div_key_p, uint8_t mac[4]);
void loclass_iclass_calc_div_key(uint8_t *csn, uint8_t *key, uint8_t *div_key, bool elite);
#endif // OPTIMIZED_CIPHER_H
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