CHG: some textual change and some syntax suger changes.

[proxmark3-svn] / client / nonce2key / crapto1.c

diff --git a/client/nonce2key/crapto1.c b/client/nonce2key/crapto1.c
index 1015e27a74b2a866078cb0ca350113081bd95baa..0339190f095dae2e19d887f2636eafe909e91601 100644 (file)
--- a/client/nonce2key/crapto1.c
+++ b/client/nonce2key/crapto1.c
@@ -1,21 +1,21 @@
 /*  crapto1.c\r
 \r
 /*  crapto1.c\r
 \r

-       This program is free software; you can redistribute it and/or\r
-       modify it under the terms of the GNU General Public License\r
-       as published by the Free Software Foundation; either version 2\r
-       of the License, or (at your option) any later version.\r
-\r
-       This program is distributed in the hope that it will be useful,\r
-       but WITHOUT ANY WARRANTY; without even the implied warranty of\r
-       MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\r
-       GNU General Public License for more details.\r
-\r
-       You should have received a copy of the GNU General Public License\r
-       along with this program; if not, write to the Free Software\r
-       Foundation, Inc., 51 Franklin Street, Fifth Floor,\r
-       Boston, MA  02110-1301, US$\r
-\r
-       Copyright (C) 2008-2008 bla <blapost@gmail.com>\r
+    This program is free software; you can redistribute it and/or\r
+    modify it under the terms of the GNU General Public License\r
+    as published by the Free Software Foundation; either version 2\r
+    of the License, or (at your option) any later version.\r
+\r
+    This program is distributed in the hope that it will be useful,\r
+    but WITHOUT ANY WARRANTY; without even the implied warranty of\r
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the\r
+    GNU General Public License for more details.\r
+\r
+    You should have received a copy of the GNU General Public License\r
+    along with this program; if not, write to the Free Software\r
+    Foundation, Inc., 51 Franklin Street, Fifth Floor,\r
+    Boston, MA  02110-1301, US$\r
+\r
+    Copyright (C) 2008-2014 bla <blapost@gmail.com>\r

 */\r
 #include "crapto1.h"\r
 #include <stdlib.h>\r
 */\r
 #include "crapto1.h"\r
 #include <stdlib.h>\r


@@ -24,98 +24,17 @@
 static uint8_t filterlut[1 << 20];\r
 static void __attribute__((constructor)) fill_lut()\r
 {\r
 static uint8_t filterlut[1 << 20];\r
 static void __attribute__((constructor)) fill_lut()\r
 {\r

-               uint32_t i;\r
-               for(i = 0; i < 1 << 20; ++i)\r
-                               filterlut[i] = filter(i);\r
+       uint32_t i;\r
+       for(i = 0; i < 1 << 20; ++i)\r
+               filterlut[i] = filter(i);\r

 }\r
 #define filter(x) (filterlut[(x) & 0xfffff])\r
 #endif\r
 \r
 }\r
 #define filter(x) (filterlut[(x) & 0xfffff])\r
 #endif\r
 \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 *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
-/** binsearch\r
- * Binary search for the first occurence of *stop's MSB in sorted [start,stop]\r
- */\r
-static inline uint32_t*\r
-binsearch(uint32_t *start, uint32_t *stop)\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
-}\r
-\r

 /** update_contribution\r
  * helper, calculates the partial linear feedback contributions and puts in MSB\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
 {\r
        uint32_t p = *item >> 25;\r
 \r


@@ -127,49 +46,40 @@ update_contribution(uint32_t *item, const uint32_t mask1, const uint32_t mask2)
 /** extend_table\r
  * using a bit of the keystream extend the table of possible lfsr states\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
 {\r
        in <<= 24;\r

-\r
-       for(uint32_t *p = tbl; p <= *end; p++) {\r
-               *p <<= 1;\r
-               if(filter(*p) != filter(*p | 1)) {                              // replace\r
-                       *p |= filter(*p) ^ bit;\r
-                       update_contribution(p, m1, m2);\r
-                       *p ^= in;\r
-               } else if(filter(*p) == bit) {                                  // insert\r
-                       *++*end = p[1];\r
-                       p[1] = p[0] | 1;\r
-                       update_contribution(p, m1, m2);\r
-                       *p++ ^= in;\r
-                       update_contribution(p, m1, m2);\r
-                       *p ^= in;\r
-               } else {                                                                                // drop\r
-                       *p-- = *(*end)--;\r
-               }\r
-       }\r
-\r
+       for(*tbl <<= 1; tbl <= *end; *++tbl <<= 1)\r
+               if(filter(*tbl) ^ filter(*tbl | 1)) {\r
+                       *tbl |= filter(*tbl) ^ bit;\r
+                       update_contribution(tbl, m1, m2);\r
+                       *tbl ^= in;\r
+               } else if(filter(*tbl) == bit) {\r
+                       *++*end = tbl[1];\r
+                       tbl[1] = tbl[0] | 1;\r
+                       update_contribution(tbl, m1, m2);\r
+                       *tbl++ ^= in;\r
+                       update_contribution(tbl, m1, m2);\r
+                       *tbl ^= in;\r
+               } else\r
+                       *tbl-- = *(*end)--;\r

 }\r
 }\r

-\r
-\r

 /** extend_table_simple\r
  * using a bit of the keystream extend the table of possible lfsr states\r
  */\r
 /** extend_table_simple\r
  * using a bit of the keystream extend the table of possible lfsr states\r
  */\r

-static inline void\r
-extend_table_simple(uint32_t *tbl, uint32_t **end, int bit)\r
+static inline void extend_table_simple(uint32_t *tbl, uint32_t **end, int bit)\r

 {\r
 {\r

-       for(*tbl <<= 1; tbl <= *end; *++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) {                // insert\r
                        *++*end = *++tbl;\r
                        *tbl = tbl[-1] | 1;\r
                if(filter(*tbl) ^ filter(*tbl | 1)) {   // replace\r
                        *tbl |= filter(*tbl) ^ bit;\r
                } else if(filter(*tbl) == bit) {                // insert\r
                        *++*end = *++tbl;\r
                        *tbl = tbl[-1] | 1;\r

-               } else                                                                  // drop\r
+               } else  {                                                               // drop\r

                        *tbl-- = *(*end)--;\r
                        *tbl-- = *(*end)--;\r

+               }\r
+       }\r

 }\r
 }\r

-\r
-\r

 /** recover\r
  * recursively narrow down the search space, 4 bits of keystream at a time\r
  */\r
 /** recover\r
  * recursively narrow down the search space, 4 bits of keystream at a time\r
  */\r


@@ -187,20 +97,21 @@ recover(uint32_t *o_head, uint32_t *o_tail, uint32_t oks,
                        for(o = o_head; o <= o_tail; ++o, ++sl) {\r
                                sl->even = *o;\r
                                sl->odd = *e ^ parity(*o & LF_POLY_ODD);\r
                        for(o = o_head; o <= o_tail; ++o, ++sl) {\r
                                sl->even = *o;\r
                                sl->odd = *e ^ parity(*o & LF_POLY_ODD);\r

+                               sl[1].odd = sl[1].even = 0;\r

                        }\r
                }\r
                        }\r
                }\r

-               sl->odd = sl->even = 0;\r

                return sl;\r
        }\r
 \r
        for(uint32_t i = 0; i < 4 && rem--; i++) {\r
                return sl;\r
        }\r
 \r
        for(uint32_t i = 0; i < 4 && rem--; i++) {\r

-               extend_table(o_head, &o_tail, (oks >>= 1) & 1,\r
-                       LF_POLY_EVEN << 1 | 1, LF_POLY_ODD << 1, 0);\r
+               oks >>= 1;\r
+               eks >>= 1;\r
+               in >>= 2;\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
                if(o_head > o_tail)\r
                        return sl;\r
 \r

-               extend_table(e_head, &e_tail, (eks >>= 1) & 1,\r
-                       LF_POLY_ODD, LF_POLY_EVEN << 1 | 1, (in >>= 2) & 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
                if(e_head > e_tail)\r
                        return sl;\r
        }\r


@@ -237,20 +148,24 @@ struct Crypto1State* lfsr_recovery32(uint32_t ks2, uint32_t in)
        even_head = even_tail = malloc(sizeof(uint32_t) << 21);\r
        statelist =  malloc(sizeof(struct Crypto1State) << 18);\r
        if(!odd_tail-- || !even_tail-- || !statelist) {\r
        even_head = even_tail = malloc(sizeof(uint32_t) << 21);\r
        statelist =  malloc(sizeof(struct Crypto1State) << 18);\r
        if(!odd_tail-- || !even_tail-- || !statelist) {\r

+               free(statelist);\r
+               statelist = 0;\r

                goto out;\r
        }\r
                goto out;\r
        }\r

+\r

        statelist->odd = statelist->even = 0;\r
 \r
        // allocate memory for out of place bucket_sort\r
        bucket_array_t bucket;\r
        statelist->odd = statelist->even = 0;\r
 \r
        // allocate memory for out of place bucket_sort\r
        bucket_array_t bucket;\r

-       for (uint32_t i = 0; i < 2; i++)\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
                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
+                                goto out;\r

                        }\r
                }\r
                        }\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
 \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


@@ -269,24 +184,19 @@ struct Crypto1State* lfsr_recovery32(uint32_t ks2, uint32_t in)
        // 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
        // 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

-\r

        in = (in >> 16 & 0xff) | (in << 16) | (in & 0xff00);            // Byte swapping\r
        in = (in >> 16 & 0xff) | (in << 16) | (in & 0xff00);            // Byte swapping\r

-\r
-       recover(odd_head, odd_tail, oks,\r
-               even_head, even_tail, eks, 11, statelist, in << 1, bucket);\r
-\r
+       recover(odd_head, odd_tail, oks, even_head, even_tail, eks, 11, statelist, in << 1, bucket);\r

 \r
 out:\r
 \r
 out:\r

-       free(odd_head);\r
-       free(even_head);\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
        for (uint32_t i = 0; i < 2; i++)\r
                for (uint32_t j = 0; j <= 0xff; j++)\r
                        free(bucket[i][j].head);\r

-\r
+       free(odd_head);\r
+       free(even_head);\r

        return statelist;\r
 }\r
 \r
        return statelist;\r
 }\r
 \r

-static const uint32_t S1[] = {     0x62141, 0x310A0, 0x18850, 0x0C428, 0x06214,\r
+static const uint32_t S1[] = { 0x62141, 0x310A0, 0x18850, 0x0C428, 0x06214,\r

        0x0310A, 0x85E30, 0xC69AD, 0x634D6, 0xB5CDE, 0xDE8DA, 0x6F46D, 0xB3C83,\r
        0x59E41, 0xA8995, 0xD027F, 0x6813F, 0x3409F, 0x9E6FA};\r
 static const uint32_t S2[] = {  0x3A557B00, 0x5D2ABD80, 0x2E955EC0, 0x174AAF60,\r
        0x0310A, 0x85E30, 0xC69AD, 0x634D6, 0xB5CDE, 0xDE8DA, 0x6F46D, 0xB3C83,\r
        0x59E41, 0xA8995, 0xD027F, 0x6813F, 0x3409F, 0x9E6FA};\r
 static const uint32_t S2[] = {  0x3A557B00, 0x5D2ABD80, 0x2E955EC0, 0x174AAF60,\r


@@ -323,12 +233,12 @@ struct Crypto1State* lfsr_recovery64(uint32_t ks2, uint32_t ks3)
        sl->odd = sl->even = 0;\r
 \r
        for(i = 30; i >= 0; i -= 2) {\r
        sl->odd = sl->even = 0;\r
 \r
        for(i = 30; i >= 0; i -= 2) {\r

-               oks[i >> 1] = BIT(ks2, i ^ 24);\r
-               oks[16 + (i >> 1)] = BIT(ks3, i ^ 24);\r
+               oks[i >> 1] = BEBIT(ks2, i);\r
+               oks[16 + (i >> 1)] = BEBIT(ks3, i);\r

        }\r
        for(i = 31; i >= 0; i -= 2) {\r
        }\r
        for(i = 31; i >= 0; i -= 2) {\r

-               eks[i >> 1] = BIT(ks2, i ^ 24);\r
-               eks[16 + (i >> 1)] = BIT(ks3, i ^ 24);\r
+               eks[i >> 1] = BEBIT(ks2, i);\r
+               eks[16 + (i >> 1)] = BEBIT(ks3, i);\r

        }\r
 \r
        for(i = 0xfffff; i >= 0; --i) {\r
        }\r
 \r
        for(i = 0xfffff; i >= 0; --i) {\r


@@ -379,41 +289,95 @@ struct Crypto1State* lfsr_recovery64(uint32_t ks2, uint32_t ks3)
 /** lfsr_rollback_bit\r
  * Rollback the shift register in order to get previous states\r
  */\r
 /** lfsr_rollback_bit\r
  * Rollback the shift register in order to get previous states\r
  */\r

-void lfsr_rollback_bit(struct Crypto1State *s, uint32_t in, int fb)\r
+uint8_t lfsr_rollback_bit(struct Crypto1State *s, uint32_t in, int fb)\r

 {\r
        int out;\r
 {\r
        int out;\r

-       uint32_t tmp;\r
+       uint8_t ret;\r
+       uint32_t t;\r

 \r
        s->odd &= 0xffffff;\r
 \r
        s->odd &= 0xffffff;\r

-       tmp = s->odd;\r
-       s->odd = s->even;\r
-       s->even = tmp;\r
+       t = s->odd, s->odd = s->even, s->even = t;\r

 \r
        out = s->even & 1;\r
        out ^= LF_POLY_EVEN & (s->even >>= 1);\r
        out ^= LF_POLY_ODD & s->odd;\r
        out ^= !!in;\r
 \r
        out = s->even & 1;\r
        out ^= LF_POLY_EVEN & (s->even >>= 1);\r
        out ^= LF_POLY_ODD & s->odd;\r
        out ^= !!in;\r

-       out ^= filter(s->odd) & !!fb;\r
+       out ^= (ret = filter(s->odd)) & !!fb;\r

 \r
        s->even |= parity(out) << 23;\r
 \r
        s->even |= parity(out) << 23;\r

+       return ret;\r

 }\r
 /** lfsr_rollback_byte\r
  * Rollback the shift register in order to get previous states\r
  */\r
 }\r
 /** lfsr_rollback_byte\r
  * Rollback the shift register in order to get previous states\r
  */\r

-void lfsr_rollback_byte(struct Crypto1State *s, uint32_t in, int fb)\r
+uint8_t lfsr_rollback_byte(struct Crypto1State *s, uint32_t in, int fb)\r

 {\r
 {\r

-       int i;\r
+       /*\r
+       int i, ret = 0;\r

        for (i = 7; i >= 0; --i)\r
        for (i = 7; i >= 0; --i)\r

-               lfsr_rollback_bit(s, BEBIT(in, i), fb);\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
  * Rollback the shift register in order to get previous states\r
  */\r
 }\r
 /** lfsr_rollback_word\r
  * Rollback the shift register in order to get previous states\r
  */\r

-void lfsr_rollback_word(struct Crypto1State *s, uint32_t in, int fb)\r
+uint32_t lfsr_rollback_word(struct Crypto1State *s, uint32_t in, int fb)\r

 {\r
 {\r

+       /*\r

        int i;\r
        int i;\r

+       uint32_t ret = 0;\r

        for (i = 31; i >= 0; --i)\r
        for (i = 31; i >= 0; --i)\r

-               lfsr_rollback_bit(s, BEBIT(in, i), fb);\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
 /** nonce_distance\r
 }\r
 \r
 /** nonce_distance\r


@@ -447,86 +411,63 @@ static uint32_t fastfwd[2][8] = {
  * Described in the "dark side" paper. It returns an -1 terminated array\r
  * of possible partial(21 bit) secret state.\r
  * The required keystream(ks) needs to contain the keystream that was used to\r
  * Described in the "dark side" paper. It returns an -1 terminated array\r
  * of possible partial(21 bit) secret state.\r
  * The required keystream(ks) needs to contain the keystream that was used to\r

- * encrypt the NACK which is observed when varying only the 4 last bits of Nr\r
+ * encrypt the NACK which is observed when varying only the 3 last bits of Nr\r

  * only correct iff [NR_3] ^ NR_3 does not depend on Nr_3\r
  */\r
 uint32_t *lfsr_prefix_ks(uint8_t ks[8], int isodd)\r
 {\r
  * only correct iff [NR_3] ^ NR_3 does not depend on Nr_3\r
  */\r
 uint32_t *lfsr_prefix_ks(uint8_t ks[8], int isodd)\r
 {\r

-       uint32_t *candidates = malloc(4 << 21);\r
+       uint32_t *candidates = malloc(4 << 10);\r
+       if(!candidates) return 0;\r
+       \r

        uint32_t c,  entry;\r
        uint32_t c,  entry;\r

-       int size, i;\r
-\r
-       if(!candidates)\r
-               return 0;\r
-\r
-       size = (1 << 21) - 1;\r
-       for(i = 0; i <= size; ++i)\r
-               candidates[i] = i;\r
-\r
-       for(c = 0;  c < 8; ++c)\r
-               for(i = 0;i <= size; ++i) {\r
-                       entry = candidates[i] ^ fastfwd[isodd][c];\r
+       int size = 0, i, good;\r

 \r
 \r

-                       if(filter(entry >> 1) == BIT(ks[c], isodd))\r
-                               if(filter(entry) == BIT(ks[c], isodd + 2))\r
-                                       continue;\r
-\r
-                       candidates[i--] = candidates[size--];\r
+       for(i = 0; i < 1 << 21; ++i) {\r
+               for(c = 0, good = 1; good && c < 8; ++c) {\r
+                       entry = i ^ fastfwd[isodd][c];\r
+                       good &= (BIT(ks[c], isodd) == filter(entry >> 1));\r
+                       good &= (BIT(ks[c], isodd + 2) == filter(entry));\r

                }\r
                }\r

+               if(good)\r
+                       candidates[size++] = i;\r
+       }\r

 \r
 \r

-       candidates[size + 1] = -1;\r
+       candidates[size] = -1;\r

 \r
        return candidates;\r
 }\r
 \r
 \r
        return candidates;\r
 }\r
 \r

-/** brute_top\r
+/** check_pfx_parity\r

  * helper function which eliminates possible secret states using parity bits\r
  */\r
  * helper function which eliminates possible secret states using parity bits\r
  */\r

-static struct Crypto1State*\r
-brute_top(uint32_t prefix, uint32_t rresp, unsigned char parities[8][8],\r
-                 uint32_t odd, uint32_t even, struct Crypto1State* sl, uint8_t no_chk)\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
 {\r

-       struct Crypto1State s;\r
-       uint32_t ks1, nr, ks2, rr, ks3, good, c;\r
-\r
-       for(c = 0; c < 8; ++c) {\r
-               s.odd = odd ^ fastfwd[1][c];\r
-               s.even = even ^ fastfwd[0][c];\r
+       uint32_t ks1, nr, ks2, rr, ks3, c, good = 1;\r

 \r
 \r

-               lfsr_rollback_bit(&s, 0, 0);\r
-               lfsr_rollback_bit(&s, 0, 0);\r
-               lfsr_rollback_bit(&s, 0, 0);\r
+       for(c = 0; good && c < 8; ++c) {\r
+               sl->odd = odd ^ fastfwd[1][c];\r
+               sl->even = even ^ fastfwd[0][c];\r

 \r
 \r

-               lfsr_rollback_word(&s, 0, 0);\r
-               lfsr_rollback_word(&s, prefix | c << 5, 1);\r
+               lfsr_rollback_bit(sl, 0, 0);\r
+               lfsr_rollback_bit(sl, 0, 0);\r

 \r
 \r

-               sl->odd = s.odd;\r
-               sl->even = s.even;\r
+               ks3 = lfsr_rollback_bit(sl, 0, 0);\r
+               ks2 = lfsr_rollback_word(sl, 0, 0);\r
+               ks1 = lfsr_rollback_word(sl, prefix | c << 5, 1);\r

 \r
 \r

-               if (no_chk)\r
-                       break;\r
-\r
-               ks1 = crypto1_word(&s, prefix | c << 5, 1);\r
-               ks2 = crypto1_word(&s,0,0);\r
-               ks3 = crypto1_word(&s, 0,0);\r

                nr = ks1 ^ (prefix | c << 5);\r
                rr = ks2 ^ rresp;\r
 \r
                nr = ks1 ^ (prefix | c << 5);\r
                rr = ks2 ^ rresp;\r
 \r

-               good = 1;\r

                good &= parity(nr & 0x000000ff) ^ parities[c][3] ^ BIT(ks2, 24);\r
                good &= parity(rr & 0xff000000) ^ parities[c][4] ^ BIT(ks2, 16);\r
                good &= parity(rr & 0x00ff0000) ^ parities[c][5] ^ BIT(ks2,  8);\r
                good &= parity(rr & 0x0000ff00) ^ parities[c][6] ^ BIT(ks2,  0);\r
                good &= parity(nr & 0x000000ff) ^ parities[c][3] ^ BIT(ks2, 24);\r
                good &= parity(rr & 0xff000000) ^ parities[c][4] ^ BIT(ks2, 16);\r
                good &= parity(rr & 0x00ff0000) ^ parities[c][5] ^ BIT(ks2,  8);\r
                good &= parity(rr & 0x0000ff00) ^ parities[c][6] ^ BIT(ks2,  0);\r

-               good &= parity(rr & 0x000000ff) ^ parities[c][7] ^ BIT(ks3, 24);\r
-\r
-               if(!good)\r
-                       return sl;\r
+               good &= parity(rr & 0x000000ff) ^ parities[c][7] ^ ks3;\r

        }\r
 \r
        }\r
 \r

-       return ++sl;\r
+       return sl + good;\r

 }\r
 \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
 /** lfsr_common_prefix\r
  * Implentation of the common prefix attack.\r
  * Requires the 28 bit constant prefix used as reader nonce (pfx)\r


@@ -536,8 +477,8 @@ brute_top(uint32_t prefix, uint32_t rresp, unsigned char parities[8][8],
  * It returns a zero terminated list of possible cipher states after the\r
  * tag nonce was fed in\r
  */\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], uint8_t no_par)\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
 {\r
        struct Crypto1State *statelist, *s;\r
        uint32_t *odd, *even, *o, *e, top;\r


@@ -545,29 +486,24 @@ lfsr_common_prefix(uint32_t pfx, uint32_t rr, uint8_t ks[8], uint8_t par[8][8],
        odd = lfsr_prefix_ks(ks, 1);\r
        even = lfsr_prefix_ks(ks, 0);\r
 \r
        odd = lfsr_prefix_ks(ks, 1);\r
        even = lfsr_prefix_ks(ks, 0);\r
 \r

-       statelist = malloc((sizeof *statelist) << 21);  //how large should be?\r
-       if(!statelist || !odd || !even)\r
-       {\r
-                               free(statelist);\r
-                               free(odd);\r
-                               free(even);\r
-                               return 0;\r
+       s = statelist = malloc((sizeof *statelist) << 20);\r
+       if(!s || !odd || !even) {\r
+               free(statelist);\r
+               statelist = 0;\r
+               goto out;\r

        }\r
 \r
        }\r
 \r

-       s = statelist;\r
-       for(o = odd; *o != -1; ++o)\r
-               for(e = even; *e != -1; ++e)\r
+       for(o = odd; *o + 1; ++o)\r
+               for(e = even; *e + 1; ++e)\r

                        for(top = 0; top < 64; ++top) {\r
                        for(top = 0; top < 64; ++top) {\r

-                               *o = (*o & 0x1fffff) | (top << 21);\r
-                               *e = (*e & 0x1fffff) | (top >> 3) << 21;\r
-                               s = brute_top(pfx, rr, par, *o, *e, s, no_par);\r
+                               *o += 1 << 21;\r
+                               *e += (!(top & 7) + 1) << 21;\r
+                               s = check_pfx_parity(pfx, rr, par, *o, *e, s);\r

                        }\r
 \r
                        }\r
 \r

-       s->odd = s->even = -1;\r
-       //printf("state count = %d\n",s-statelist);\r
-\r
+       s->odd = s->even = 0;\r
+out:\r

        free(odd);\r
        free(even);\r
        free(odd);\r
        free(even);\r

-\r

        return statelist;\r
 }\r
        return statelist;\r
 }\r