CHG: plotting of clock

[proxmark3-svn] / tools / mfkey / crapto1.c

diff --git a/tools/mfkey/crapto1.c b/tools/mfkey/crapto1.c
index 5715ad27a95c2221f9729b432e1894c45eaeb669..b6e0e87d5858876b247674f5bb815286c888406d 100755 (executable)
--- a/tools/mfkey/crapto1.c
+++ b/tools/mfkey/crapto1.c
@@ -31,49 +31,75 @@ static void __attribute__((constructor)) fill_lut()
 #define filter(x) (filterlut[(x) & 0xfffff])\r
 #endif\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, 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
 {\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
 \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


@@ -85,8 +111,7 @@ 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
        for(*tbl <<= 1; tbl <= *end; *++tbl <<= 1)\r
 {\r
        in <<= 24;\r
        for(*tbl <<= 1; tbl <= *end; *++tbl <<= 1)\r


@@ -109,14 +134,16 @@ extend_table(uint32_t *tbl, uint32_t **end, int bit, int m1, int m2, uint32_t in
  */\r
 static inline void extend_table_simple(uint32_t *tbl, uint32_t **end, int bit)\r
 {\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
                        *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
                        *tbl-- = *(*end)--;\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


@@ -124,9 +151,10 @@ static inline void extend_table_simple(uint32_t *tbl, uint32_t **end, int bit)
 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
 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


@@ -140,35 +168,26 @@ recover(uint32_t *o_head, uint32_t *o_tail, uint32_t oks,
                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

                oks >>= 1;\r
                eks >>= 1;\r
                in >>= 2;\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
                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
                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
 \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
                }\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
 \r
        return sl;\r
 }\r


@@ -184,6 +203,7 @@ 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


@@ -200,6 +220,19 @@ struct Crypto1State* lfsr_recovery32(uint32_t ks2, uint32_t in)
 \r
        statelist->odd = statelist->even = 0;\r
 \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
        for(i = 1 << 20; i >= 0; --i) {\r
                if(filter(i) == (oks & 1))\r
                        *++odd_tail = i;\r


@@ -207,16 +240,22 @@ 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
-       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
 \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
        free(odd_head);\r
        free(even_head);\r
        return statelist;\r


@@ -338,9 +377,21 @@ uint8_t lfsr_rollback_bit(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
 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
        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
        return ret;\r
 }\r
 /** lfsr_rollback_word\r


@@ -348,10 +399,49 @@ uint8_t lfsr_rollback_byte(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
 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
        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
        return ret;\r
 }\r
 \r


@@ -378,6 +468,8 @@ int nonce_distance(uint32_t from, uint32_t to)
 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
 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
 /** lfsr_prefix_ks\r
  *\r
  * Is an exported helper function from the common prefix attack\r


@@ -389,11 +481,11 @@ static uint32_t fastfwd[2][8] = {
  */\r
 uint32_t *lfsr_prefix_ks(uint8_t ks[8], int isodd)\r
 {\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
 \r
        for(i = 0; i < 1 << 21; ++i) {\r
                for(c = 0, good = 1; good && c < 8; ++c) {\r


@@ -413,9 +505,7 @@ uint32_t *lfsr_prefix_ks(uint8_t ks[8], int isodd)
 /** check_pfx_parity\r
  * helper function which eliminates possible secret states using parity bits\r
  */\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
 {\r
        uint32_t ks1, nr, ks2, rr, ks3, c, good = 1;\r
 \r


@@ -443,12 +533,17 @@ check_pfx_parity(uint32_t prefix, uint32_t rresp, uint8_t parities[8][8],
        return sl + good;\r
 } \r
 \r
        return sl + good;\r
 } \r
 \r

-\r

 /** lfsr_common_prefix\r
  * Implentation of the common prefix attack.\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
  */\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
 {\r
        struct Crypto1State *statelist, *s;\r
        uint32_t *odd, *even, *o, *e, top;\r