From: iceman1001 <iceman@iuse.se>
Date: Tue, 19 Jan 2016 15:17:29 +0000 (+0100)
Subject: CHG:  Crapto1 v3.3  now with comments,  and I've tried to unnest some loops.
X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/commitdiff_plain/a1afa550ea5b602b6d8bc69bdc6f018696b21ff0

CHG:  Crapto1 v3.3  now with comments,  and I've tried to unnest some loops.
---

diff --git a/tools/mfkey/crapto1.c b/tools/mfkey/crapto1.c
index d0ca9e83..995d0069 100755
--- a/tools/mfkey/crapto1.c
+++ b/tools/mfkey/crapto1.c
@@ -184,6 +184,7 @@ struct Crypto1State* lfsr_recovery32(uint32_t ks2, uint32_t in)
 	uint32_t *even_head = 0, *even_tail = 0, eks = 0;
 	int i;
 
+	// split the keystream into an odd and even part
 	for(i = 31; i >= 0; i -= 2)
 		oks = oks << 1 | BEBIT(ks2, i);
 	for(i = 30; i >= 0; i -= 2)
@@ -200,6 +201,7 @@ struct Crypto1State* lfsr_recovery32(uint32_t ks2, uint32_t in)
 
 	statelist->odd = statelist->even = 0;
 
+	// initialize statelists: add all possible states which would result into the rightmost 2 bits of the keystream
 	for(i = 1 << 20; i >= 0; --i) {
 		if(filter(i) == (oks & 1))
 			*++odd_tail = i;
@@ -207,11 +209,15 @@ struct Crypto1State* lfsr_recovery32(uint32_t ks2, uint32_t in)
 			*++even_tail = i;
 	}
 
+	// extend the statelists. Look at the next 8 Bits of the keystream (4 Bit each odd and even):
 	for(i = 0; i < 4; i++) {
 		extend_table_simple(odd_head,  &odd_tail, (oks >>= 1) & 1);
 		extend_table_simple(even_head, &even_tail, (eks >>= 1) & 1);
 	}
 
+	// the statelists now contain all states which could have generated the last 10 Bits of the keystream.
+	// 22 bits to go to recover 32 bits in total. From now on, we need to take the "in"
+	// parameter into account.
 	in = (in >> 16 & 0xff) | (in << 16) | (in & 0xff00);
 	recover(odd_head, odd_tail, oks,
 		even_head, even_tail, eks, 11, statelist, in << 1);
@@ -338,9 +344,21 @@ uint8_t lfsr_rollback_bit(struct Crypto1State *s, uint32_t in, int fb)
  */
 uint8_t lfsr_rollback_byte(struct Crypto1State *s, uint32_t in, int fb)
 {
+	/*
 	int i, ret = 0;
 	for (i = 7; i >= 0; --i)
 		ret |= lfsr_rollback_bit(s, BIT(in, i), fb) << i;
+*/
+
+	uint8_t ret = 0;
+	ret |= lfsr_rollback_bit(s, BIT(in, 7), fb) << 7;
+	ret |= lfsr_rollback_bit(s, BIT(in, 6), fb) << 6;
+	ret |= lfsr_rollback_bit(s, BIT(in, 5), fb) << 5;
+	ret |= lfsr_rollback_bit(s, BIT(in, 4), fb) << 4;
+	ret |= lfsr_rollback_bit(s, BIT(in, 3), fb) << 3;
+	ret |= lfsr_rollback_bit(s, BIT(in, 2), fb) << 2;
+	ret |= lfsr_rollback_bit(s, BIT(in, 1), fb) << 1;
+	ret |= lfsr_rollback_bit(s, BIT(in, 0), fb) << 0;
 	return ret;
 }
 /** lfsr_rollback_word
@@ -348,10 +366,50 @@ uint8_t lfsr_rollback_byte(struct Crypto1State *s, uint32_t in, int fb)
  */
 uint32_t lfsr_rollback_word(struct Crypto1State *s, uint32_t in, int fb)
 {
+	/*
 	int i;
 	uint32_t ret = 0;
 	for (i = 31; i >= 0; --i)
 		ret |= lfsr_rollback_bit(s, BEBIT(in, i), fb) << (i ^ 24);
+*/
+	
+	uint32_t ret = 0;
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 31), fb) << (31 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 30), fb) << (30 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 29), fb) << (29 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 28), fb) << (28 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 27), fb) << (27 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 26), fb) << (26 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 25), fb) << (25 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 24), fb) << (24 ^ 24);
+
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 23), fb) << (23 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 22), fb) << (22 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 21), fb) << (21 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 20), fb) << (20 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 19), fb) << (19 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 18), fb) << (18 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 17), fb) << (17 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 16), fb) << (16 ^ 24);
+	
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 15), fb) << (15 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 14), fb) << (14 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 13), fb) << (13 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 12), fb) << (12 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 11), fb) << (11 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 10), fb) << (10 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 9), fb) << (9 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 8), fb) << (8 ^ 24);
+	
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 7), fb) << (7 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 6), fb) << (6 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 5), fb) << (5 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 4), fb) << (4 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 3), fb) << (3 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 2), fb) << (2 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 1), fb) << (1 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 0), fb) << (0 ^ 24);
+	
 	return ret;
 }
 
@@ -391,8 +449,9 @@ static uint32_t fastfwd[2][8] = {
  */
 uint32_t *lfsr_prefix_ks(uint8_t ks[8], int isodd)
 {
-	uint32_t c, entry, *candidates = malloc(4 << 10);
-	int i, size = 0, good;
+	uint32_t *candidates = malloc(4 << 10);
+	uint32_t c,  entry;
+	int size = 0, i, good;
 
 	if(!candidates)
 		return 0;
@@ -479,5 +538,8 @@ struct Crypto1State* lfsr_common_prefix(uint32_t pfx, uint32_t rr, uint8_t ks[8]
 
 	s->odd = s->even = 0;
 
+	free(odd);
+	free(even);
+
 	return statelist;
 }
diff --git a/tools/mfkey/crapto1.h b/tools/mfkey/crapto1.h
index bf7be4f0..a7483d72 100755
--- a/tools/mfkey/crapto1.h
+++ b/tools/mfkey/crapto1.h
@@ -43,6 +43,9 @@ uint8_t lfsr_rollback_bit(struct Crypto1State* s, uint32_t in, int fb);
 uint8_t lfsr_rollback_byte(struct Crypto1State* s, uint32_t in, int fb);
 uint32_t lfsr_rollback_word(struct Crypto1State* s, uint32_t in, int fb);
 int nonce_distance(uint32_t from, uint32_t to);
+#define SWAPENDIAN(x)\
+	(x = (x >> 8 & 0xff00ff) | (x & 0xff00ff) << 8, x = x >> 16 | x << 16)
+	
 #define FOREACH_VALID_NONCE(N, FILTER, FSIZE)\
 	uint32_t __n = 0,__M = 0, N = 0;\
 	int __i;\
@@ -66,7 +69,7 @@ static inline int parity(uint32_t x)
 	x ^= x >> 4;
 	return BIT(0x6996, x & 0xf);
 #else
-        asm(    "movl %1, %%eax\n"
+	__asm__(	"movl %1, %%eax\n"
 		"mov %%ax, %%cx\n"
 		"shrl $0x10, %%eax\n"
 		"xor %%ax, %%cx\n"
diff --git a/tools/mfkey/crypto1.c b/tools/mfkey/crypto1.c
index e2aab71b..f4554605 100755
--- a/tools/mfkey/crypto1.c
+++ b/tools/mfkey/crypto1.c
@@ -20,9 +20,6 @@
 #include "crapto1.h"
 #include <stdlib.h>
 
-#define SWAPENDIAN(x)\
-	(x = (x >> 8 & 0xff00ff) | (x & 0xff00ff) << 8, x = x >> 16 | x << 16)
-
 struct Crypto1State * crypto1_create(uint64_t key)
 {
 	struct Crypto1State *s = malloc(sizeof(*s));
@@ -49,6 +46,7 @@ void crypto1_get_lfsr(struct Crypto1State *state, uint64_t *lfsr)
 uint8_t crypto1_bit(struct Crypto1State *s, uint8_t in, int is_encrypted)
 {
 	uint32_t feedin;
+	uint32_t tmp;
 	uint8_t ret = filter(s->odd);
 
 	feedin  = ret & !!is_encrypted;
@@ -57,26 +55,76 @@ uint8_t crypto1_bit(struct Crypto1State *s, uint8_t in, int is_encrypted)
 	feedin ^= LF_POLY_EVEN & s->even;
 	s->even = s->even << 1 | parity(feedin);
 
-	s->odd ^= (s->odd ^= s->even, s->even ^= s->odd);
+	tmp = s->odd;
+	s->odd = s->even;
+	s->even = tmp;
 
 	return ret;
 }
 uint8_t crypto1_byte(struct Crypto1State *s, uint8_t in, int is_encrypted)
 {
+	/*
 	uint8_t i, ret = 0;
 
 	for (i = 0; i < 8; ++i)
 		ret |= crypto1_bit(s, BIT(in, i), is_encrypted) << i;
-
+	*/
+	// unfold loop
+	uint8_t ret = 0;
+	ret |= crypto1_bit(s, BIT(in, 0), is_encrypted) << 0;
+	ret |= crypto1_bit(s, BIT(in, 1), is_encrypted) << 1;
+	ret |= crypto1_bit(s, BIT(in, 2), is_encrypted) << 2;
+	ret |= crypto1_bit(s, BIT(in, 3), is_encrypted) << 3;
+	ret |= crypto1_bit(s, BIT(in, 4), is_encrypted) << 4;
+	ret |= crypto1_bit(s, BIT(in, 5), is_encrypted) << 5;
+	ret |= crypto1_bit(s, BIT(in, 6), is_encrypted) << 6;
+	ret |= crypto1_bit(s, BIT(in, 7), is_encrypted) << 7;
 	return ret;
 }
 uint32_t crypto1_word(struct Crypto1State *s, uint32_t in, int is_encrypted)
 {
+	/*
 	uint32_t i, ret = 0;
 
 	for (i = 0; i < 32; ++i)
 		ret |= crypto1_bit(s, BEBIT(in, i), is_encrypted) << (i ^ 24);
-
+*/
+	uint32_t ret = 0;
+	ret |= crypto1_bit(s, BEBIT(in, 0), is_encrypted) << (0 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 1), is_encrypted) << (1 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 2), is_encrypted) << (2 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 3), is_encrypted) << (3 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 4), is_encrypted) << (4 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 5), is_encrypted) << (5 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 6), is_encrypted) << (6 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 7), is_encrypted) << (7 ^ 24);
+	
+	ret |= crypto1_bit(s, BEBIT(in, 8), is_encrypted) << (8 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 9), is_encrypted) << (9 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 10), is_encrypted) << (10 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 11), is_encrypted) << (11 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 12), is_encrypted) << (12 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 13), is_encrypted) << (13 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 14), is_encrypted) << (14 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 15), is_encrypted) << (15 ^ 24);
+
+	ret |= crypto1_bit(s, BEBIT(in, 16), is_encrypted) << (16 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 17), is_encrypted) << (17 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 18), is_encrypted) << (18 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 19), is_encrypted) << (19 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 20), is_encrypted) << (20 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 21), is_encrypted) << (21 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 22), is_encrypted) << (22 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 23), is_encrypted) << (23 ^ 24);
+
+	ret |= crypto1_bit(s, BEBIT(in, 24), is_encrypted) << (24 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 25), is_encrypted) << (25 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 26), is_encrypted) << (26 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 27), is_encrypted) << (27 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 28), is_encrypted) << (28 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 29), is_encrypted) << (29 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 30), is_encrypted) << (30 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 31), is_encrypted) << (31 ^ 24);
 	return ret;
 }
 
diff --git a/tools/nonce2key/crapto1.c b/tools/nonce2key/crapto1.c
index 8d514a0c..10dedcb5 100644
--- a/tools/nonce2key/crapto1.c
+++ b/tools/nonce2key/crapto1.c
@@ -184,6 +184,7 @@ struct Crypto1State* lfsr_recovery32(uint32_t ks2, uint32_t in)
 	uint32_t *even_head = 0, *even_tail = 0, eks = 0;
 	int i;
 
+	// split the keystream into an odd and even part
 	for(i = 31; i >= 0; i -= 2)
 		oks = oks << 1 | BEBIT(ks2, i);
 	for(i = 30; i >= 0; i -= 2)
@@ -200,6 +201,7 @@ struct Crypto1State* lfsr_recovery32(uint32_t ks2, uint32_t in)
 
 	statelist->odd = statelist->even = 0;
 
+	// initialize statelists: add all possible states which would result into the rightmost 2 bits of the keystream
 	for(i = 1 << 20; i >= 0; --i) {
 		if(filter(i) == (oks & 1))
 			*++odd_tail = i;
@@ -207,11 +209,15 @@ struct Crypto1State* lfsr_recovery32(uint32_t ks2, uint32_t in)
 			*++even_tail = i;
 	}
 
+	// extend the statelists. Look at the next 8 Bits of the keystream (4 Bit each odd and even):
 	for(i = 0; i < 4; i++) {
 		extend_table_simple(odd_head,  &odd_tail, (oks >>= 1) & 1);
 		extend_table_simple(even_head, &even_tail, (eks >>= 1) & 1);
 	}
 
+	// the statelists now contain all states which could have generated the last 10 Bits of the keystream.
+	// 22 bits to go to recover 32 bits in total. From now on, we need to take the "in"
+	// parameter into account.
 	in = (in >> 16 & 0xff) | (in << 16) | (in & 0xff00);
 	recover(odd_head, odd_tail, oks,
 		even_head, even_tail, eks, 11, statelist, in << 1);
@@ -338,9 +344,21 @@ uint8_t lfsr_rollback_bit(struct Crypto1State *s, uint32_t in, int fb)
  */
 uint8_t lfsr_rollback_byte(struct Crypto1State *s, uint32_t in, int fb)
 {
+	/*
 	int i, ret = 0;
 	for (i = 7; i >= 0; --i)
 		ret |= lfsr_rollback_bit(s, BIT(in, i), fb) << i;
+*/
+
+	uint8_t ret = 0;
+	ret |= lfsr_rollback_bit(s, BIT(in, 7), fb) << 7;
+	ret |= lfsr_rollback_bit(s, BIT(in, 6), fb) << 6;
+	ret |= lfsr_rollback_bit(s, BIT(in, 5), fb) << 5;
+	ret |= lfsr_rollback_bit(s, BIT(in, 4), fb) << 4;
+	ret |= lfsr_rollback_bit(s, BIT(in, 3), fb) << 3;
+	ret |= lfsr_rollback_bit(s, BIT(in, 2), fb) << 2;
+	ret |= lfsr_rollback_bit(s, BIT(in, 1), fb) << 1;
+	ret |= lfsr_rollback_bit(s, BIT(in, 0), fb) << 0;
 	return ret;
 }
 /** lfsr_rollback_word
@@ -348,10 +366,50 @@ uint8_t lfsr_rollback_byte(struct Crypto1State *s, uint32_t in, int fb)
  */
 uint32_t lfsr_rollback_word(struct Crypto1State *s, uint32_t in, int fb)
 {
+	/*
 	int i;
 	uint32_t ret = 0;
 	for (i = 31; i >= 0; --i)
 		ret |= lfsr_rollback_bit(s, BEBIT(in, i), fb) << (i ^ 24);
+*/
+	
+	uint32_t ret = 0;
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 31), fb) << (31 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 30), fb) << (30 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 29), fb) << (29 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 28), fb) << (28 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 27), fb) << (27 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 26), fb) << (26 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 25), fb) << (25 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 24), fb) << (24 ^ 24);
+
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 23), fb) << (23 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 22), fb) << (22 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 21), fb) << (21 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 20), fb) << (20 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 19), fb) << (19 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 18), fb) << (18 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 17), fb) << (17 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 16), fb) << (16 ^ 24);
+	
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 15), fb) << (15 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 14), fb) << (14 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 13), fb) << (13 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 12), fb) << (12 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 11), fb) << (11 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 10), fb) << (10 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 9), fb) << (9 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 8), fb) << (8 ^ 24);
+	
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 7), fb) << (7 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 6), fb) << (6 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 5), fb) << (5 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 4), fb) << (4 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 3), fb) << (3 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 2), fb) << (2 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 1), fb) << (1 ^ 24);
+	ret |= lfsr_rollback_bit(s, BEBIT(in, 0), fb) << (0 ^ 24);
+	
 	return ret;
 }
 
@@ -391,8 +449,9 @@ static uint32_t fastfwd[2][8] = {
  */
 uint32_t *lfsr_prefix_ks(uint8_t ks[8], int isodd)
 {
-	uint32_t c, entry, *candidates = malloc(4 << 10);
-	int i, size = 0, good;
+	uint32_t *candidates = malloc(4 << 10);
+	uint32_t c,  entry;
+	int size = 0, i, good;
 
 	if(!candidates)
 		return 0;
@@ -479,5 +538,8 @@ struct Crypto1State* lfsr_common_prefix(uint32_t pfx, uint32_t rr, uint8_t ks[8]
 
 	s->odd = s->even = 0;
 
+	free(odd);
+	free(even);
+
 	return statelist;
 }
diff --git a/tools/nonce2key/crapto1.h b/tools/nonce2key/crapto1.h
index bf7be4f0..cc49b2e6 100644
--- a/tools/nonce2key/crapto1.h
+++ b/tools/nonce2key/crapto1.h
@@ -36,13 +36,17 @@ uint32_t prng_successor(uint32_t x, uint32_t n);
 struct Crypto1State* lfsr_recovery32(uint32_t ks2, uint32_t in);
 struct Crypto1State* lfsr_recovery64(uint32_t ks2, uint32_t ks3);
 uint32_t *lfsr_prefix_ks(uint8_t ks[8], int isodd);
-struct Crypto1State*
-lfsr_common_prefix(uint32_t pfx, uint32_t rr, uint8_t ks[8], uint8_t par[8][8]);
+struct Crypto1State* lfsr_common_prefix(uint32_t pfx, uint32_t rr, uint8_t ks[8], uint8_t par[8][8]);
+struct Crypto1State* lfsr_common_prefix_ex(uint32_t pfx, uint32_t rr, uint8_t ks[8], uint8_t par[8][8]);
+
 
 uint8_t lfsr_rollback_bit(struct Crypto1State* s, uint32_t in, int fb);
 uint8_t lfsr_rollback_byte(struct Crypto1State* s, uint32_t in, int fb);
 uint32_t lfsr_rollback_word(struct Crypto1State* s, uint32_t in, int fb);
 int nonce_distance(uint32_t from, uint32_t to);
+#define SWAPENDIAN(x)\
+	(x = (x >> 8 & 0xff00ff) | (x & 0xff00ff) << 8, x = x >> 16 | x << 16)
+	
 #define FOREACH_VALID_NONCE(N, FILTER, FSIZE)\
 	uint32_t __n = 0,__M = 0, N = 0;\
 	int __i;\
@@ -66,7 +70,7 @@ static inline int parity(uint32_t x)
 	x ^= x >> 4;
 	return BIT(0x6996, x & 0xf);
 #else
-        asm(    "movl %1, %%eax\n"
+	__asm__(	"movl %1, %%eax\n"
 		"mov %%ax, %%cx\n"
 		"shrl $0x10, %%eax\n"
 		"xor %%ax, %%cx\n"
diff --git a/tools/nonce2key/crypto1.c b/tools/nonce2key/crypto1.c
index e2aab71b..f4554605 100644
--- a/tools/nonce2key/crypto1.c
+++ b/tools/nonce2key/crypto1.c
@@ -20,9 +20,6 @@
 #include "crapto1.h"
 #include <stdlib.h>
 
-#define SWAPENDIAN(x)\
-	(x = (x >> 8 & 0xff00ff) | (x & 0xff00ff) << 8, x = x >> 16 | x << 16)
-
 struct Crypto1State * crypto1_create(uint64_t key)
 {
 	struct Crypto1State *s = malloc(sizeof(*s));
@@ -49,6 +46,7 @@ void crypto1_get_lfsr(struct Crypto1State *state, uint64_t *lfsr)
 uint8_t crypto1_bit(struct Crypto1State *s, uint8_t in, int is_encrypted)
 {
 	uint32_t feedin;
+	uint32_t tmp;
 	uint8_t ret = filter(s->odd);
 
 	feedin  = ret & !!is_encrypted;
@@ -57,26 +55,76 @@ uint8_t crypto1_bit(struct Crypto1State *s, uint8_t in, int is_encrypted)
 	feedin ^= LF_POLY_EVEN & s->even;
 	s->even = s->even << 1 | parity(feedin);
 
-	s->odd ^= (s->odd ^= s->even, s->even ^= s->odd);
+	tmp = s->odd;
+	s->odd = s->even;
+	s->even = tmp;
 
 	return ret;
 }
 uint8_t crypto1_byte(struct Crypto1State *s, uint8_t in, int is_encrypted)
 {
+	/*
 	uint8_t i, ret = 0;
 
 	for (i = 0; i < 8; ++i)
 		ret |= crypto1_bit(s, BIT(in, i), is_encrypted) << i;
-
+	*/
+	// unfold loop
+	uint8_t ret = 0;
+	ret |= crypto1_bit(s, BIT(in, 0), is_encrypted) << 0;
+	ret |= crypto1_bit(s, BIT(in, 1), is_encrypted) << 1;
+	ret |= crypto1_bit(s, BIT(in, 2), is_encrypted) << 2;
+	ret |= crypto1_bit(s, BIT(in, 3), is_encrypted) << 3;
+	ret |= crypto1_bit(s, BIT(in, 4), is_encrypted) << 4;
+	ret |= crypto1_bit(s, BIT(in, 5), is_encrypted) << 5;
+	ret |= crypto1_bit(s, BIT(in, 6), is_encrypted) << 6;
+	ret |= crypto1_bit(s, BIT(in, 7), is_encrypted) << 7;
 	return ret;
 }
 uint32_t crypto1_word(struct Crypto1State *s, uint32_t in, int is_encrypted)
 {
+	/*
 	uint32_t i, ret = 0;
 
 	for (i = 0; i < 32; ++i)
 		ret |= crypto1_bit(s, BEBIT(in, i), is_encrypted) << (i ^ 24);
-
+*/
+	uint32_t ret = 0;
+	ret |= crypto1_bit(s, BEBIT(in, 0), is_encrypted) << (0 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 1), is_encrypted) << (1 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 2), is_encrypted) << (2 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 3), is_encrypted) << (3 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 4), is_encrypted) << (4 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 5), is_encrypted) << (5 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 6), is_encrypted) << (6 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 7), is_encrypted) << (7 ^ 24);
+	
+	ret |= crypto1_bit(s, BEBIT(in, 8), is_encrypted) << (8 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 9), is_encrypted) << (9 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 10), is_encrypted) << (10 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 11), is_encrypted) << (11 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 12), is_encrypted) << (12 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 13), is_encrypted) << (13 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 14), is_encrypted) << (14 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 15), is_encrypted) << (15 ^ 24);
+
+	ret |= crypto1_bit(s, BEBIT(in, 16), is_encrypted) << (16 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 17), is_encrypted) << (17 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 18), is_encrypted) << (18 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 19), is_encrypted) << (19 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 20), is_encrypted) << (20 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 21), is_encrypted) << (21 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 22), is_encrypted) << (22 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 23), is_encrypted) << (23 ^ 24);
+
+	ret |= crypto1_bit(s, BEBIT(in, 24), is_encrypted) << (24 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 25), is_encrypted) << (25 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 26), is_encrypted) << (26 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 27), is_encrypted) << (27 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 28), is_encrypted) << (28 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 29), is_encrypted) << (29 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 30), is_encrypted) << (30 ^ 24);
+	ret |= crypto1_bit(s, BEBIT(in, 31), is_encrypted) << (31 ^ 24);
 	return ret;
 }