X-Git-Url: http://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/7862f4ad5b30bb5143980158051280d8229fb698..7847961b25c507b5a291c8ddb9aa1c1b222a4b11:/tools/mfkey/crapto1.c

diff --git a/tools/mfkey/crapto1.c b/tools/mfkey/crapto1.c
new file mode 100755
index 00000000..9d491d12
--- /dev/null
+++ b/tools/mfkey/crapto1.c
@@ -0,0 +1,478 @@
+/*  crapto1.c
+
+    This program is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License
+    as published by the Free Software Foundation; either version 2
+    of the License, or (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor,
+    Boston, MA  02110-1301, US$
+
+    Copyright (C) 2008-2008 bla <blapost@gmail.com>
+*/
+#include "crapto1.h"
+#include <stdlib.h>
+
+#if !defined LOWMEM && defined __GNUC__
+static uint8_t filterlut[1 << 20];
+static void __attribute__((constructor)) fill_lut()
+{
+        uint32_t i;
+        for(i = 0; i < 1 << 20; ++i)
+                filterlut[i] = filter(i);
+}
+#define filter(x) (filterlut[(x) & 0xfffff])
+#endif
+
+static void quicksort(uint32_t* const start, uint32_t* const stop)
+{
+	uint32_t *it = start + 1, *rit = stop;
+
+	if(it > rit)
+		return;
+
+	while(it < rit)
+		if(*it <= *start)
+			++it;
+		else if(*rit > *start)
+			--rit;
+		else
+			*it ^= (*it ^= *rit, *rit ^= *it);
+
+	if(*rit >= *start)
+		--rit;
+	if(rit != start)
+		*rit ^= (*rit ^= *start, *start ^= *rit);
+
+	quicksort(start, rit - 1);
+	quicksort(rit + 1, stop);
+}
+/** binsearch
+ * Binary search for the first occurence of *stop's MSB in sorted [start,stop]
+ */
+static inline uint32_t* binsearch(uint32_t *start, uint32_t *stop)
+{
+	uint32_t mid, val = *stop & 0xff000000;
+	while(start != stop)
+		if(start[mid = (stop - start) >> 1] > val)
+			stop = &start[mid];
+		else
+			start += mid + 1;
+
+	return start;
+}
+
+/** update_contribution
+ * helper, calculates the partial linear feedback contributions and puts in MSB
+ */
+static inline void
+update_contribution(uint32_t *item, const uint32_t mask1, const uint32_t mask2)
+{
+	uint32_t p = *item >> 25;
+
+	p = p << 1 | parity(*item & mask1);
+	p = p << 1 | parity(*item & mask2);
+	*item = p << 24 | (*item & 0xffffff);
+}
+
+/** extend_table
+ * using a bit of the keystream extend the table of possible lfsr states
+ */
+static inline void
+extend_table(uint32_t *tbl, uint32_t **end, int bit, int m1, int m2, uint32_t in)
+{
+	in <<= 24;
+	for(*tbl <<= 1; tbl <= *end; *++tbl <<= 1)
+		if(filter(*tbl) ^ filter(*tbl | 1)) {
+			*tbl |= filter(*tbl) ^ bit;
+			update_contribution(tbl, m1, m2);
+			*tbl ^= in;
+		} else if(filter(*tbl) == bit) {
+			*++*end = tbl[1];
+			tbl[1] = tbl[0] | 1;
+			update_contribution(tbl, m1, m2);
+			*tbl++ ^= in;
+			update_contribution(tbl, m1, m2);
+			*tbl ^= in;
+		} else
+			*tbl-- = *(*end)--;
+}
+/** extend_table_simple
+ * using a bit of the keystream extend the table of possible lfsr states
+ */
+static inline void extend_table_simple(uint32_t *tbl, uint32_t **end, int bit)
+{
+	for(*tbl <<= 1; tbl <= *end; *++tbl <<= 1)
+		if(filter(*tbl) ^ filter(*tbl | 1))
+			*tbl |= filter(*tbl) ^ bit;
+		else if(filter(*tbl) == bit) {
+			*++*end = *++tbl;
+			*tbl = tbl[-1] | 1;
+		} else
+			*tbl-- = *(*end)--;
+}
+/** recover
+ * recursively narrow down the search space, 4 bits of keystream at a time
+ */
+static struct Crypto1State*
+recover(uint32_t *o_head, uint32_t *o_tail, uint32_t oks,
+	uint32_t *e_head, uint32_t *e_tail, uint32_t eks, int rem,
+	struct Crypto1State *sl, uint32_t in)
+{
+	uint32_t *o, *e, i;
+
+	if(rem == -1) {
+		for(e = e_head; e <= e_tail; ++e) {
+			*e = *e << 1 ^ parity(*e & LF_POLY_EVEN) ^ !!(in & 4);
+			for(o = o_head; o <= o_tail; ++o, ++sl) {
+				sl->even = *o;
+				sl->odd = *e ^ parity(*o & LF_POLY_ODD);
+				sl[1].odd = sl[1].even = 0;
+			}
+		}
+		return sl;
+	}
+
+	for(i = 0; i < 4 && rem--; i++) {
+		oks >>= 1;
+		eks >>= 1;
+		in >>= 2;
+		extend_table(o_head, &o_tail, oks & 1, LF_POLY_EVEN << 1 | 1,
+			     LF_POLY_ODD << 1, 0);
+		if(o_head > o_tail)
+			return sl;
+
+		extend_table(e_head, &e_tail, eks & 1, LF_POLY_ODD,
+			     LF_POLY_EVEN << 1 | 1, in & 3);
+		if(e_head > e_tail)
+			return sl;
+	}
+
+	quicksort(o_head, o_tail);
+	quicksort(e_head, e_tail);
+
+	while(o_tail >= o_head && e_tail >= e_head)
+		if(((*o_tail ^ *e_tail) >> 24) == 0) {
+			o_tail = binsearch(o_head, o = o_tail);
+			e_tail = binsearch(e_head, e = e_tail);
+			sl = recover(o_tail--, o, oks,
+				     e_tail--, e, eks, rem, sl, in);
+		}
+		else if(*o_tail > *e_tail)
+			o_tail = binsearch(o_head, o_tail) - 1;
+		else
+			e_tail = binsearch(e_head, e_tail) - 1;
+
+	return sl;
+}
+/** lfsr_recovery
+ * recover the state of the lfsr given 32 bits of the keystream
+ * additionally you can use the in parameter to specify the value
+ * that was fed into the lfsr at the time the keystream was generated
+ */
+struct Crypto1State* lfsr_recovery32(uint32_t ks2, uint32_t in)
+{
+	struct Crypto1State *statelist;
+	uint32_t *odd_head = 0, *odd_tail = 0, oks = 0;
+	uint32_t *even_head = 0, *even_tail = 0, eks = 0;
+	int i;
+
+	for(i = 31; i >= 0; i -= 2)
+		oks = oks << 1 | BEBIT(ks2, i);
+	for(i = 30; i >= 0; i -= 2)
+		eks = eks << 1 | BEBIT(ks2, i);
+
+	odd_head = odd_tail = malloc(sizeof(uint32_t) << 21);
+	even_head = even_tail = malloc(sizeof(uint32_t) << 21);
+	statelist =  malloc(sizeof(struct Crypto1State) << 18);
+	if(!odd_tail-- || !even_tail-- || !statelist) {
+		free(statelist);
+		statelist = 0;
+		goto out;
+	}
+
+	statelist->odd = statelist->even = 0;
+
+	for(i = 1 << 20; i >= 0; --i) {
+		if(filter(i) == (oks & 1))
+			*++odd_tail = i;
+		if(filter(i) == (eks & 1))
+			*++even_tail = i;
+	}
+
+	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);
+	}
+
+	in = (in >> 16 & 0xff) | (in << 16) | (in & 0xff00);
+	recover(odd_head, odd_tail, oks,
+		even_head, even_tail, eks, 11, statelist, in << 1);
+
+out:
+	free(odd_head);
+	free(even_head);
+	return statelist;
+}
+
+static const uint32_t S1[] = {     0x62141, 0x310A0, 0x18850, 0x0C428, 0x06214,
+	0x0310A, 0x85E30, 0xC69AD, 0x634D6, 0xB5CDE, 0xDE8DA, 0x6F46D, 0xB3C83,
+	0x59E41, 0xA8995, 0xD027F, 0x6813F, 0x3409F, 0x9E6FA};
+static const uint32_t S2[] = {  0x3A557B00, 0x5D2ABD80, 0x2E955EC0, 0x174AAF60,
+	0x0BA557B0, 0x05D2ABD8, 0x0449DE68, 0x048464B0, 0x42423258, 0x278192A8,
+	0x156042D0, 0x0AB02168, 0x43F89B30, 0x61FC4D98, 0x765EAD48, 0x7D8FDD20,
+	0x7EC7EE90, 0x7F63F748, 0x79117020};
+static const uint32_t T1[] = {
+	0x4F37D, 0x279BE, 0x97A6A, 0x4BD35, 0x25E9A, 0x12F4D, 0x097A6, 0x80D66,
+	0xC4006, 0x62003, 0xB56B4, 0x5AB5A, 0xA9318, 0xD0F39, 0x6879C, 0xB057B,
+	0x582BD, 0x2C15E, 0x160AF, 0x8F6E2, 0xC3DC4, 0xE5857, 0x72C2B, 0x39615,
+	0x98DBF, 0xC806A, 0xE0680, 0x70340, 0x381A0, 0x98665, 0x4C332, 0xA272C};
+static const uint32_t T2[] = {  0x3C88B810, 0x5E445C08, 0x2982A580, 0x14C152C0,
+	0x4A60A960, 0x253054B0, 0x52982A58, 0x2FEC9EA8, 0x1156C4D0, 0x08AB6268,
+	0x42F53AB0, 0x217A9D58, 0x161DC528, 0x0DAE6910, 0x46D73488, 0x25CB11C0,
+	0x52E588E0, 0x6972C470, 0x34B96238, 0x5CFC3A98, 0x28DE96C8, 0x12CFC0E0,
+	0x4967E070, 0x64B3F038, 0x74F97398, 0x7CDC3248, 0x38CE92A0, 0x1C674950,
+	0x0E33A4A8, 0x01B959D0, 0x40DCACE8, 0x26CEDDF0};
+static const uint32_t C1[] = { 0x846B5, 0x4235A, 0x211AD};
+static const uint32_t C2[] = { 0x1A822E0, 0x21A822E0, 0x21A822E0};
+/** Reverse 64 bits of keystream into possible cipher states
+ * Variation mentioned in the paper. Somewhat optimized version
+ */
+struct Crypto1State* lfsr_recovery64(uint32_t ks2, uint32_t ks3)
+{
+	struct Crypto1State *statelist, *sl;
+	uint8_t oks[32], eks[32], hi[32];
+	uint32_t low = 0,  win = 0;
+	uint32_t *tail, table[1 << 16];
+	int i, j;
+
+	sl = statelist = malloc(sizeof(struct Crypto1State) << 4);
+	if(!sl)
+		return 0;
+	sl->odd = sl->even = 0;
+
+	for(i = 30; i >= 0; i -= 2) {
+		oks[i >> 1] = BEBIT(ks2, i);
+		oks[16 + (i >> 1)] = BEBIT(ks3, i);
+	}
+	for(i = 31; i >= 0; i -= 2) {
+		eks[i >> 1] = BEBIT(ks2, i);
+		eks[16 + (i >> 1)] = BEBIT(ks3, i);
+	}
+
+	for(i = 0xfffff; i >= 0; --i) {
+		if (filter(i) != oks[0])
+			continue;
+
+		*(tail = table) = i;
+		for(j = 1; tail >= table && j < 29; ++j)
+			extend_table_simple(table, &tail, oks[j]);
+
+		if(tail < table)
+			continue;
+
+		for(j = 0; j < 19; ++j)
+			low = low << 1 | parity(i & S1[j]);
+		for(j = 0; j < 32; ++j)
+			hi[j] = parity(i & T1[j]);
+
+		for(; tail >= table; --tail) {
+			for(j = 0; j < 3; ++j) {
+				*tail = *tail << 1;
+				*tail |= parity((i & C1[j]) ^ (*tail & C2[j]));
+				if(filter(*tail) != oks[29 + j])
+					goto continue2;
+			}
+
+			for(j = 0; j < 19; ++j)
+				win = win << 1 | parity(*tail & S2[j]);
+
+			win ^= low;
+			for(j = 0; j < 32; ++j) {
+				win = win << 1 ^ hi[j] ^ parity(*tail & T2[j]);
+				if(filter(win) != eks[j])
+					goto continue2;
+			}
+
+			*tail = *tail << 1 | parity(LF_POLY_EVEN & *tail);
+			sl->odd = *tail ^ parity(LF_POLY_ODD & win);
+			sl->even = win;
+			++sl;
+			sl->odd = sl->even = 0;
+			continue2:;
+		}
+	}
+	return statelist;
+}
+
+/** lfsr_rollback_bit
+ * Rollback the shift register in order to get previous states
+ */
+uint8_t lfsr_rollback_bit(struct Crypto1State *s, uint32_t in, int fb)
+{
+	int out;
+	uint8_t ret;
+
+	s->odd &= 0xffffff;
+	s->odd ^= (s->odd ^= s->even, s->even ^= s->odd);
+
+	out = s->even & 1;
+	out ^= LF_POLY_EVEN & (s->even >>= 1);
+	out ^= LF_POLY_ODD & s->odd;
+	out ^= !!in;
+	out ^= (ret = filter(s->odd)) & !!fb;
+
+	s->even |= parity(out) << 23;
+	return ret;
+}
+/** lfsr_rollback_byte
+ * Rollback the shift register in order to get previous states
+ */
+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;
+	return ret;
+}
+/** lfsr_rollback_word
+ * Rollback the shift register in order to get previous states
+ */
+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);
+	return ret;
+}
+
+/** nonce_distance
+ * x,y valid tag nonces, then prng_successor(x, nonce_distance(x, y)) = y
+ */
+static uint16_t *dist = 0;
+int nonce_distance(uint32_t from, uint32_t to)
+{
+	uint16_t x, i;
+	if(!dist) {
+		dist = malloc(2 << 16);
+		if(!dist)
+			return -1;
+		for (x = i = 1; i; ++i) {
+			dist[(x & 0xff) << 8 | x >> 8] = i;
+			x = x >> 1 | (x ^ x >> 2 ^ x >> 3 ^ x >> 5) << 15;
+		}
+	}
+	return (65535 + dist[to >> 16] - dist[from >> 16]) % 65535;
+}
+
+
+static uint32_t fastfwd[2][8] = {
+	{ 0, 0x4BC53, 0xECB1, 0x450E2, 0x25E29, 0x6E27A, 0x2B298, 0x60ECB},
+	{ 0, 0x1D962, 0x4BC53, 0x56531, 0xECB1, 0x135D3, 0x450E2, 0x58980}};
+/** lfsr_prefix_ks
+ *
+ * Is an exported helper function from the common prefix attack
+ * Described in the "dark side" paper. It returns an -1 terminated array
+ * of possible partial(21 bit) secret state.
+ * The required keystream(ks) needs to contain the keystream that was used to
+ * encrypt the NACK which is observed when varying only the 3 last bits of Nr
+ * only correct iff [NR_3] ^ NR_3 does not depend on Nr_3
+ */
+uint32_t *lfsr_prefix_ks(uint8_t ks[8], int isodd)
+{
+	uint32_t c, entry, *candidates = malloc(4 << 10);
+	int i, size = 0, good;
+
+	if(!candidates)
+		return 0;
+
+	for(i = 0; i < 1 << 21; ++i) {
+		for(c = 0, good = 1; good && c < 8; ++c) {
+			entry = i ^ fastfwd[isodd][c];
+			good &= (BIT(ks[c], isodd) == filter(entry >> 1));
+			good &= (BIT(ks[c], isodd + 2) == filter(entry));
+		}
+		if(good)
+			candidates[size++] = i;
+	}
+
+	candidates[size] = -1;
+
+	return candidates;
+}
+
+/** check_pfx_parity
+ * helper function which eliminates possible secret states using parity bits
+ */
+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)
+{
+	uint32_t ks1, nr, ks2, rr, ks3, c, good = 1;
+
+	for(c = 0; good && c < 8; ++c) {
+		sl->odd = odd ^ fastfwd[1][c];
+		sl->even = even ^ fastfwd[0][c];
+
+		lfsr_rollback_bit(sl, 0, 0);
+		lfsr_rollback_bit(sl, 0, 0);
+
+		ks3 = lfsr_rollback_bit(sl, 0, 0);
+		ks2 = lfsr_rollback_word(sl, 0, 0);
+		ks1 = lfsr_rollback_word(sl, prefix | c << 5, 1);
+
+		nr = ks1 ^ (prefix | c << 5);
+		rr = ks2 ^ rresp;
+
+		good &= parity(nr & 0x000000ff) ^ parities[c][3] ^ BIT(ks2, 24);
+		good &= parity(rr & 0xff000000) ^ parities[c][4] ^ BIT(ks2, 16);
+		good &= parity(rr & 0x00ff0000) ^ parities[c][5] ^ BIT(ks2,  8);
+		good &= parity(rr & 0x0000ff00) ^ parities[c][6] ^ BIT(ks2,  0);
+		good &= parity(rr & 0x000000ff) ^ parities[c][7] ^ ks3;
+	}
+
+	return sl + good;
+} 
+
+
+/** lfsr_common_prefix
+ * Implentation of the common prefix attack.
+ */
+struct Crypto1State*
+lfsr_common_prefix(uint32_t pfx, uint32_t rr, uint8_t ks[8], uint8_t par[8][8])
+{
+	struct Crypto1State *statelist, *s;
+	uint32_t *odd, *even, *o, *e, top;
+
+	odd = lfsr_prefix_ks(ks, 1);
+	even = lfsr_prefix_ks(ks, 0);
+
+	s = statelist = malloc((sizeof *statelist) << 20);
+	if(!s || !odd || !even) {
+		free(statelist);
+		statelist = 0;
+                goto out;
+	}
+
+	for(o = odd; *o + 1; ++o)
+		for(e = even; *e + 1; ++e)
+			for(top = 0; top < 64; ++top) {
+				*o += 1 << 21;
+				*e += (!(top & 7) + 1) << 21;
+				s = check_pfx_parity(pfx, rr, par, *o, *e, s);
+			}
+
+	s->odd = s->even = 0;
+out:
+	free(odd);
+	free(even);
+	return statelist;
+}