Potential fix for 0-length usb packets seen on OSX

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

diff --git a/client/nonce2key/crapto1.c b/client/nonce2key/crapto1.c
index c0a158b56e7498fbe29c09280cb1898be38475e9..1015e27a74b2a866078cb0ca350113081bd95baa 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) 2008-2008 bla <blapost@gmail.com>\r

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


@@ -24,36 +24,77 @@
 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

-static void quicksort(uint32_t* const start, uint32_t* const stop)\r
-{\r
-       uint32_t *it = start + 1, *rit = stop;\r

 \r
 \r

-       if(it > rit)\r
-               return;\r

 \r
 \r

-       while(it < rit)\r
-               if(*it <= *start)\r
-                       ++it;\r
-               else if(*rit > *start)\r
-                       --rit;\r
-               else\r
-                       *it ^= (*it ^= *rit, *rit ^= *it);\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

-       if(*rit >= *start)\r
-               --rit;\r
-       if(rit != start)\r
-               *rit ^= (*rit ^= *start, *start ^= *rit);\r

 \r
 \r

-       quicksort(start, rit - 1);\r
-       quicksort(rit + 1, stop);\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

 /** binsearch\r
  * Binary search for the first occurence of *stop's MSB in sorted [start,stop]\r
  */\r
 /** binsearch\r
  * Binary search for the first occurence of *stop's MSB in sorted [start,stop]\r
  */\r


@@ -90,21 +131,28 @@ 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
 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
-               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
+       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

 }\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


@@ -112,23 +160,26 @@ static inline void
 extend_table_simple(uint32_t *tbl, uint32_t **end, int bit)\r
 {\r
        for(*tbl <<= 1; tbl <= *end; *++tbl <<= 1)\r
 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
+               if(filter(*tbl) ^ filter(*tbl | 1)) {   // replace\r

                        *tbl |= filter(*tbl) ^ bit;\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
                        *++*end = *++tbl;\r
                        *tbl = tbl[-1] | 1;\r

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

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

+\r
+\r

 /** recover\r
  * recursively narrow down the search space, 4 bits of keystream at a time\r
  */\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
 /** recover\r
  * recursively narrow down the search space, 4 bits of keystream at a time\r
  */\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
 {\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
 \r
        if(rem == -1) {\r
                for(e = e_head; e <= e_tail; ++e) {\r


@@ -136,13 +187,13 @@ 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
                return sl;\r
        }\r
 \r

-       for(i = 0; i < 4 && rem--; i++) {\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
                if(o_head > o_tail)\r
                extend_table(o_head, &o_tail, (oks >>= 1) & 1,\r
                        LF_POLY_EVEN << 1 | 1, LF_POLY_ODD << 1, 0);\r
                if(o_head > o_tail)\r


@@ -154,20 +205,13 @@ recover(uint32_t *o_head, uint32_t *o_tail, uint32_t oks,
                        return sl;\r
        }\r
 \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
 \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
-               }\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
+       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

 \r
        return sl;\r
 }\r
 \r
        return sl;\r
 }\r


@@ -183,6 +227,7 @@ struct Crypto1State* lfsr_recovery32(uint32_t ks2, uint32_t in)
        uint32_t *even_head = 0, *even_tail = 0, eks = 0;\r
        int i;\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
        for(i = 31; i >= 0; i -= 2)\r
                oks = oks << 1 | BEBIT(ks2, i);\r
        for(i = 30; i >= 0; i -= 2)\r


@@ -191,11 +236,23 @@ struct Crypto1State* lfsr_recovery32(uint32_t ks2, uint32_t in)
        odd_head = odd_tail = malloc(sizeof(uint32_t) << 21);\r
        even_head = even_tail = malloc(sizeof(uint32_t) << 21);\r
        statelist =  malloc(sizeof(struct Crypto1State) << 18);\r
        odd_head = odd_tail = malloc(sizeof(uint32_t) << 21);\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
+       if(!odd_tail-- || !even_tail-- || !statelist) {\r

                goto out;\r
                goto out;\r

-\r
+       }\r

        statelist->odd = statelist->even = 0;\r
 \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
+               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
        for(i = 1 << 20; i >= 0; --i) {\r
                if(filter(i) == (oks & 1))\r
                        *++odd_tail = i;\r


@@ -203,18 +260,29 @@ struct Crypto1State* lfsr_recovery32(uint32_t ks2, uint32_t in)
                        *++even_tail = i;\r
        }\r
 \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
        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
+       // 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
+\r

        recover(odd_head, odd_tail, oks,\r
        recover(odd_head, odd_tail, oks,\r

-               even_head, even_tail, eks, 11, statelist, in << 1);\r
+               even_head, even_tail, eks, 11, statelist, in << 1, bucket);\r
+\r

 \r
 out:\r
        free(odd_head);\r
        free(even_head);\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
+\r

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


@@ -314,9 +382,12 @@ struct Crypto1State* lfsr_recovery64(uint32_t ks2, uint32_t ks3)
 void lfsr_rollback_bit(struct Crypto1State *s, uint32_t in, int fb)\r
 {\r
        int out;\r
 void lfsr_rollback_bit(struct Crypto1State *s, uint32_t in, int fb)\r
 {\r
        int out;\r

+       uint32_t tmp;\r

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

-       s->odd ^= (s->odd ^= s->even, s->even ^= s->odd);\r
+       tmp = s->odd;\r
+       s->odd = s->even;\r
+       s->even = tmp;\r

 \r
        out = s->even & 1;\r
        out ^= LF_POLY_EVEN & (s->even >>= 1);\r
 \r
        out = s->even & 1;\r
        out ^= LF_POLY_EVEN & (s->even >>= 1);\r


@@ -413,7 +484,7 @@ uint32_t *lfsr_prefix_ks(uint8_t ks[8], int isodd)
  */\r
 static struct Crypto1State*\r
 brute_top(uint32_t prefix, uint32_t rresp, unsigned char parities[8][8],\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)\r
+                 uint32_t odd, uint32_t even, struct Crypto1State* sl, uint8_t no_chk)\r

 {\r
        struct Crypto1State s;\r
        uint32_t ks1, nr, ks2, rr, ks3, good, c;\r
 {\r
        struct Crypto1State s;\r
        uint32_t ks1, nr, ks2, rr, ks3, good, c;\r


@@ -421,17 +492,20 @@ brute_top(uint32_t prefix, uint32_t rresp, unsigned char parities[8][8],
        for(c = 0; c < 8; ++c) {\r
                s.odd = odd ^ fastfwd[1][c];\r
                s.even = even ^ fastfwd[0][c];\r
        for(c = 0; c < 8; ++c) {\r
                s.odd = odd ^ fastfwd[1][c];\r
                s.even = even ^ fastfwd[0][c];\r

-               \r
+\r

                lfsr_rollback_bit(&s, 0, 0);\r
                lfsr_rollback_bit(&s, 0, 0);\r
                lfsr_rollback_bit(&s, 0, 0);\r
                lfsr_rollback_bit(&s, 0, 0);\r
                lfsr_rollback_bit(&s, 0, 0);\r
                lfsr_rollback_bit(&s, 0, 0);\r

-               \r
+\r

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

-               \r
+\r

                sl->odd = s.odd;\r
                sl->even = s.even;\r
                sl->odd = s.odd;\r
                sl->even = s.even;\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
                ks1 = crypto1_word(&s, prefix | c << 5, 1);\r
                ks2 = crypto1_word(&s,0,0);\r
                ks3 = crypto1_word(&s, 0,0);\r


@@ -450,7 +524,7 @@ brute_top(uint32_t prefix, uint32_t rresp, unsigned char parities[8][8],
        }\r
 \r
        return ++sl;\r
        }\r
 \r
        return ++sl;\r

-} \r
+}\r

 \r
 \r
 /** lfsr_common_prefix\r
 \r
 \r
 /** lfsr_common_prefix\r


@@ -463,7 +537,7 @@ brute_top(uint32_t prefix, uint32_t rresp, unsigned char parities[8][8],
  * tag nonce was fed in\r
  */\r
 struct Crypto1State*\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
+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 *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


@@ -471,21 +545,26 @@ 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) << 20);\r
+       statelist = malloc((sizeof *statelist) << 21);  //how large should be?\r

        if(!statelist || !odd || !even)\r
        if(!statelist || !odd || !even)\r

-                return 0;\r
-\r
+       {\r
+                               free(statelist);\r
+                               free(odd);\r
+                               free(even);\r
+                               return 0;\r
+       }\r

 \r
        s = statelist;\r
 \r
        s = statelist;\r

-       for(o = odd; *o != 0xffffffff; ++o)\r
-               for(e = even; *e != 0xffffffff; ++e)\r
+       for(o = odd; *o != -1; ++o)\r
+               for(e = even; *e != -1; ++e)\r

                        for(top = 0; top < 64; ++top) {\r
                                *o = (*o & 0x1fffff) | (top << 21);\r
                                *e = (*e & 0x1fffff) | (top >> 3) << 21;\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);\r
+                               s = brute_top(pfx, rr, par, *o, *e, s, no_par);\r

                        }\r
 \r
                        }\r
 \r

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

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