#define filter(x) (filterlut[(x) & 0xfffff])\r
#endif\r
\r
-static void quicksort(uint32_t* const start, uint32_t* const stop)\r
-{\r
- uint32_t *it = start + 1, *rit = stop, t;\r
-\r
- if(it > rit)\r
- return;\r
-\r
- while(it < rit)\r
- if(*it <= *start)\r
- ++it;\r
- else if(*rit > *start)\r
- --rit;\r
- else\r
- t = *it, *it = *rit, *rit = t;\r
-\r
- if(*rit >= *start)\r
- --rit;\r
- if(rit != start)\r
- t = *rit, *rit = *start, *start = t;\r
-\r
- quicksort(start, rit - 1);\r
- quicksort(rit + 1, stop);\r
-}\r
-/** binsearch\r
- * Binary search for the first occurence of *stop's MSB in sorted [start,stop]\r
- */\r
-static inline uint32_t* binsearch(uint32_t *start, uint32_t *stop)\r
+\r
+\r
+typedef struct bucket {\r
+ uint32_t *head;\r
+ uint32_t *bp;\r
+} bucket_t;\r
+\r
+typedef bucket_t bucket_array_t[2][0x100];\r
+\r
+typedef struct bucket_info {\r
+ struct {\r
+ uint32_t *head, *tail;\r
+ } bucket_info[2][0x100];\r
+ uint32_t numbuckets;\r
+ } bucket_info_t;\r
+\r
+\r
+static void bucket_sort_intersect(uint32_t* const estart, uint32_t* const estop,\r
+ uint32_t* const ostart, uint32_t* const ostop,\r
+ bucket_info_t *bucket_info, bucket_array_t bucket)\r
{\r
- uint32_t mid, val = *stop & 0xff000000;\r
- while(start != stop)\r
- if(start[mid = (stop - start) >> 1] > val)\r
- stop = &start[mid];\r
- else\r
- start += mid + 1;\r
-\r
- return start;\r
+ uint32_t *p1, *p2;\r
+ uint32_t *start[2];\r
+ uint32_t *stop[2];\r
+\r
+ start[0] = estart;\r
+ stop[0] = estop;\r
+ start[1] = ostart;\r
+ stop[1] = ostop;\r
+\r
+ // init buckets to be empty\r
+ for (uint32_t i = 0; i < 2; i++) {\r
+ for (uint32_t j = 0x00; j <= 0xff; j++) {\r
+ bucket[i][j].bp = bucket[i][j].head;\r
+ }\r
+ }\r
+\r
+ // sort the lists into the buckets based on the MSB (contribution bits)\r
+ for (uint32_t i = 0; i < 2; i++) {\r
+ for (p1 = start[i]; p1 <= stop[i]; p1++) {\r
+ uint32_t bucket_index = (*p1 & 0xff000000) >> 24;\r
+ *(bucket[i][bucket_index].bp++) = *p1;\r
+ }\r
+ }\r
+\r
+\r
+ // write back intersecting buckets as sorted list.\r
+ // fill in bucket_info with head and tail of the bucket contents in the list and number of non-empty buckets.\r
+ uint32_t nonempty_bucket;\r
+ for (uint32_t i = 0; i < 2; i++) {\r
+ p1 = start[i];\r
+ nonempty_bucket = 0;\r
+ for (uint32_t j = 0x00; j <= 0xff; j++) {\r
+ if (bucket[0][j].bp != bucket[0][j].head && bucket[1][j].bp != bucket[1][j].head) { // non-empty intersecting buckets only\r
+ bucket_info->bucket_info[i][nonempty_bucket].head = p1;\r
+ for (p2 = bucket[i][j].head; p2 < bucket[i][j].bp; *p1++ = *p2++);\r
+ bucket_info->bucket_info[i][nonempty_bucket].tail = p1 - 1;\r
+ nonempty_bucket++;\r
+ }\r
+ }\r
+ bucket_info->numbuckets = nonempty_bucket;\r
+ }\r
}\r
\r
+\r
/** update_contribution\r
* helper, calculates the partial linear feedback contributions and puts in MSB\r
*/\r
-static inline void\r
-update_contribution(uint32_t *item, const uint32_t mask1, const uint32_t mask2)\r
+static inline void update_contribution(uint32_t *item, const uint32_t mask1, const uint32_t mask2)\r
{\r
uint32_t p = *item >> 25;\r
\r
/** extend_table\r
* using a bit of the keystream extend the table of possible lfsr states\r
*/\r
-static inline void\r
-extend_table(uint32_t *tbl, uint32_t **end, int bit, int m1, int m2, uint32_t in)\r
+static inline void extend_table(uint32_t *tbl, uint32_t **end, int bit, int m1, int m2, uint32_t in)\r
{\r
in <<= 24;\r
for(*tbl <<= 1; tbl <= *end; *++tbl <<= 1)\r
*/\r
static inline void extend_table_simple(uint32_t *tbl, uint32_t **end, int bit)\r
{\r
- for(*tbl <<= 1; tbl <= *end; *++tbl <<= 1)\r
- if(filter(*tbl) ^ filter(*tbl | 1))\r
+ for(*tbl <<= 1; tbl <= *end; *++tbl <<= 1) {\r
+ if(filter(*tbl) ^ filter(*tbl | 1)) { // replace\r
*tbl |= filter(*tbl) ^ bit;\r
- else if(filter(*tbl) == bit) {\r
+ } else if(filter(*tbl) == bit) { // insert\r
*++*end = *++tbl;\r
*tbl = tbl[-1] | 1;\r
- } else\r
+ } else { // drop\r
*tbl-- = *(*end)--;\r
+ }\r
+ }\r
}\r
/** recover\r
* recursively narrow down the search space, 4 bits of keystream at a time\r
static struct Crypto1State*\r
recover(uint32_t *o_head, uint32_t *o_tail, uint32_t oks,\r
uint32_t *e_head, uint32_t *e_tail, uint32_t eks, int rem,\r
- struct Crypto1State *sl, uint32_t in)\r
+ struct Crypto1State *sl, uint32_t in, bucket_array_t bucket)\r
{\r
- uint32_t *o, *e, i;\r
+ uint32_t *o, *e;\r
+ bucket_info_t bucket_info;\r
\r
if(rem == -1) {\r
for(e = e_head; e <= e_tail; ++e) {\r
return sl;\r
}\r
\r
- for(i = 0; i < 4 && rem--; i++) {\r
+ for(uint32_t i = 0; i < 4 && rem--; i++) {\r
oks >>= 1;\r
eks >>= 1;\r
in >>= 2;\r
- extend_table(o_head, &o_tail, oks & 1, LF_POLY_EVEN << 1 | 1,\r
- LF_POLY_ODD << 1, 0);\r
+ extend_table(o_head, &o_tail, oks & 1, LF_POLY_EVEN << 1 | 1, LF_POLY_ODD << 1, 0);\r
if(o_head > o_tail)\r
return sl;\r
\r
- extend_table(e_head, &e_tail, eks & 1, LF_POLY_ODD,\r
- LF_POLY_EVEN << 1 | 1, in & 3);\r
+ extend_table(e_head, &e_tail, eks & 1, LF_POLY_ODD, LF_POLY_EVEN << 1 | 1, in & 3);\r
if(e_head > e_tail)\r
return sl;\r
}\r
\r
- quicksort(o_head, o_tail);\r
- quicksort(e_head, e_tail);\r
+ bucket_sort_intersect(e_head, e_tail, o_head, o_tail, &bucket_info, bucket);\r
\r
- while(o_tail >= o_head && e_tail >= e_head)\r
- if(((*o_tail ^ *e_tail) >> 24) == 0) {\r
- o_tail = binsearch(o_head, o = o_tail);\r
- e_tail = binsearch(e_head, e = e_tail);\r
- sl = recover(o_tail--, o, oks,\r
- e_tail--, e, eks, rem, sl, in);\r
+ for (int i = bucket_info.numbuckets - 1; i >= 0; i--) {\r
+ sl = recover(bucket_info.bucket_info[1][i].head, bucket_info.bucket_info[1][i].tail, oks,\r
+ bucket_info.bucket_info[0][i].head, bucket_info.bucket_info[0][i].tail, eks,\r
+ rem, sl, in, bucket);\r
}\r
- else if(*o_tail > *e_tail)\r
- o_tail = binsearch(o_head, o_tail) - 1;\r
- else\r
- e_tail = binsearch(e_head, e_tail) - 1;\r
\r
return sl;\r
}\r
uint32_t *even_head = 0, *even_tail = 0, eks = 0;\r
int i;\r
\r
+ // split the keystream into an odd and even part\r
for(i = 31; i >= 0; i -= 2)\r
oks = oks << 1 | BEBIT(ks2, i);\r
for(i = 30; i >= 0; i -= 2)\r
\r
statelist->odd = statelist->even = 0;\r
\r
+ // allocate memory for out of place bucket_sort\r
+ bucket_array_t bucket;\r
+ \r
+ for (uint32_t i = 0; i < 2; i++) {\r
+ for (uint32_t j = 0; j <= 0xff; j++) {\r
+ bucket[i][j].head = malloc(sizeof(uint32_t)<<14);\r
+ if (!bucket[i][j].head) {\r
+ goto out;\r
+ }\r
+ }\r
+ }\r
+\r
+ // initialize statelists: add all possible states which would result into the rightmost 2 bits of the keystream\r
for(i = 1 << 20; i >= 0; --i) {\r
if(filter(i) == (oks & 1))\r
*++odd_tail = i;\r
*++even_tail = i;\r
}\r
\r
+ // extend the statelists. Look at the next 8 Bits of the keystream (4 Bit each odd and even):\r
for(i = 0; i < 4; i++) {\r
extend_table_simple(odd_head, &odd_tail, (oks >>= 1) & 1);\r
extend_table_simple(even_head, &even_tail, (eks >>= 1) & 1);\r
}\r
\r
- in = (in >> 16 & 0xff) | (in << 16) | (in & 0xff00);\r
- recover(odd_head, odd_tail, oks,\r
- even_head, even_tail, eks, 11, statelist, in << 1);\r
+ // the statelists now contain all states which could have generated the last 10 Bits of the keystream.\r
+ // 22 bits to go to recover 32 bits in total. From now on, we need to take the "in"\r
+ // parameter into account.\r
+ in = (in >> 16 & 0xff) | (in << 16) | (in & 0xff00); // Byte swapping\r
+ recover(odd_head, odd_tail, oks, even_head, even_tail, eks, 11, statelist, in << 1, bucket);\r
\r
out:\r
+ for (uint32_t i = 0; i < 2; i++)\r
+ for (uint32_t j = 0; j <= 0xff; j++)\r
+ free(bucket[i][j].head);\r
free(odd_head);\r
free(even_head);\r
return statelist;\r
*/\r
uint8_t lfsr_rollback_byte(struct Crypto1State *s, uint32_t in, int fb)\r
{\r
+ /*\r
int i, ret = 0;\r
for (i = 7; i >= 0; --i)\r
ret |= lfsr_rollback_bit(s, BIT(in, i), fb) << i;\r
+*/\r
+// unfold loop 20160112\r
+ uint8_t ret = 0;\r
+ ret |= lfsr_rollback_bit(s, BIT(in, 7), fb) << 7;\r
+ ret |= lfsr_rollback_bit(s, BIT(in, 6), fb) << 6;\r
+ ret |= lfsr_rollback_bit(s, BIT(in, 5), fb) << 5;\r
+ ret |= lfsr_rollback_bit(s, BIT(in, 4), fb) << 4;\r
+ ret |= lfsr_rollback_bit(s, BIT(in, 3), fb) << 3;\r
+ ret |= lfsr_rollback_bit(s, BIT(in, 2), fb) << 2;\r
+ ret |= lfsr_rollback_bit(s, BIT(in, 1), fb) << 1;\r
+ ret |= lfsr_rollback_bit(s, BIT(in, 0), fb) << 0;\r
return ret;\r
}\r
/** lfsr_rollback_word\r
*/\r
uint32_t lfsr_rollback_word(struct Crypto1State *s, uint32_t in, int fb)\r
{\r
+ /*\r
int i;\r
uint32_t ret = 0;\r
for (i = 31; i >= 0; --i)\r
ret |= lfsr_rollback_bit(s, BEBIT(in, i), fb) << (i ^ 24);\r
+*/\r
+// unfold loop 20160112\r
+ uint32_t ret = 0;\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 31), fb) << (31 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 30), fb) << (30 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 29), fb) << (29 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 28), fb) << (28 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 27), fb) << (27 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 26), fb) << (26 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 25), fb) << (25 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 24), fb) << (24 ^ 24);\r
+\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 23), fb) << (23 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 22), fb) << (22 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 21), fb) << (21 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 20), fb) << (20 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 19), fb) << (19 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 18), fb) << (18 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 17), fb) << (17 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 16), fb) << (16 ^ 24);\r
+ \r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 15), fb) << (15 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 14), fb) << (14 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 13), fb) << (13 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 12), fb) << (12 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 11), fb) << (11 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 10), fb) << (10 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 9), fb) << (9 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 8), fb) << (8 ^ 24);\r
+ \r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 7), fb) << (7 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 6), fb) << (6 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 5), fb) << (5 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 4), fb) << (4 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 3), fb) << (3 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 2), fb) << (2 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 1), fb) << (1 ^ 24);\r
+ ret |= lfsr_rollback_bit(s, BEBIT(in, 0), fb) << (0 ^ 24);\r
return ret;\r
}\r
\r
static uint32_t fastfwd[2][8] = {\r
{ 0, 0x4BC53, 0xECB1, 0x450E2, 0x25E29, 0x6E27A, 0x2B298, 0x60ECB},\r
{ 0, 0x1D962, 0x4BC53, 0x56531, 0xECB1, 0x135D3, 0x450E2, 0x58980}};\r
+\r
+\r
/** lfsr_prefix_ks\r
*\r
* Is an exported helper function from the common prefix attack\r
*/\r
uint32_t *lfsr_prefix_ks(uint8_t ks[8], int isodd)\r
{\r
- uint32_t c, entry, *candidates = malloc(4 << 10);\r
- int i, size = 0, good;\r
-\r
- if(!candidates)\r
- return 0;\r
+ uint32_t *candidates = malloc(4 << 10);\r
+ if(!candidates) return 0;\r
+ \r
+ uint32_t c, entry;\r
+ int size = 0, i, good;\r
\r
for(i = 0; i < 1 << 21; ++i) {\r
for(c = 0, good = 1; good && c < 8; ++c) {\r
/** check_pfx_parity\r
* helper function which eliminates possible secret states using parity bits\r
*/\r
-static struct Crypto1State*\r
-check_pfx_parity(uint32_t prefix, uint32_t rresp, uint8_t parities[8][8],\r
- uint32_t odd, uint32_t even, struct Crypto1State* sl)\r
+static struct Crypto1State* check_pfx_parity(uint32_t prefix, uint32_t rresp, uint8_t parities[8][8], uint32_t odd, uint32_t even, struct Crypto1State* sl)\r
{\r
uint32_t ks1, nr, ks2, rr, ks3, c, good = 1;\r
\r
return sl + good;\r
} \r
\r
-\r
/** lfsr_common_prefix\r
* Implentation of the common prefix attack.\r
+ * Requires the 28 bit constant prefix used as reader nonce (pfx)\r
+ * The reader response used (rr)\r
+ * The keystream used to encrypt the observed NACK's (ks)\r
+ * The parity bits (par)\r
+ * It returns a zero terminated list of possible cipher states after the\r
+ * tag nonce was fed in\r
*/\r
-struct Crypto1State*\r
-lfsr_common_prefix(uint32_t pfx, uint32_t rr, uint8_t ks[8], uint8_t par[8][8])\r
+\r
+struct Crypto1State* lfsr_common_prefix(uint32_t pfx, uint32_t rr, uint8_t ks[8], uint8_t par[8][8])\r
{\r
struct Crypto1State *statelist, *s;\r
uint32_t *odd, *even, *o, *e, top;\r
projects / proxmark3-svn / blobdiff