X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/proxmark3-svn/blobdiff_plain/33443e7caa26da1563402d548e0a871d53ccc23a..8c0ccdef357a5a940788cb81730f4847fe47606a:/common/crapto1/crapto1.c?ds=sidebyside diff --git a/common/crapto1/crapto1.c b/common/crapto1/crapto1.c index 6a194c46..01351731 100644 --- a/common/crapto1/crapto1.c +++ b/common/crapto1/crapto1.c @@ -15,11 +15,10 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, US$ - Copyright (C) 2008-2008 bla + Copyright (C) 2008-2014 bla */ #include "crapto1.h" #include -#include #if !defined LOWMEM && defined __GNUC__ static uint8_t filterlut[1 << 20]; @@ -95,12 +94,10 @@ static void bucket_sort_intersect(uint32_t* const estart, uint32_t* const estop, bucket_info->numbuckets = nonempty_bucket; } } - /** 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) +static inline uint32_t* binsearch(uint32_t *start, uint32_t *stop) { uint32_t mid, val = *stop & 0xff000000; while(start != stop) @@ -132,41 +129,34 @@ static inline void extend_table(uint32_t *tbl, uint32_t **end, int bit, int m1, int m2, uint32_t in) { in <<= 24; - - for(uint32_t *p = tbl; p <= *end; p++) { - *p <<= 1; - if(filter(*p) != filter(*p | 1)) { // replace - *p |= filter(*p) ^ bit; - update_contribution(p, m1, m2); - *p ^= in; - } else if(filter(*p) == bit) { // insert - *++*end = p[1]; - p[1] = p[0] | 1; - update_contribution(p, m1, m2); - *p++ ^= in; - update_contribution(p, m1, m2); - *p ^= in; - } else { // drop - *p-- = *(*end)--; - } - } - + 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) +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)) { // replace + if(filter(*tbl) ^ filter(*tbl | 1)) *tbl |= filter(*tbl) ^ bit; - } else if(filter(*tbl) == bit) { // insert + else if(filter(*tbl) == bit) { *++*end = *++tbl; *tbl = tbl[-1] | 1; - } else // drop + + } else *tbl-- = *(*end)--; } @@ -179,7 +169,7 @@ 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, bucket_array_t bucket) { - uint32_t *o, *e; + uint32_t *o, *e, i; bucket_info_t bucket_info; if(rem == -1) { @@ -188,24 +178,26 @@ recover(uint32_t *o_head, uint32_t *o_tail, uint32_t oks, 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; } } - sl->odd = sl->even = 0; return sl; } - for(uint32_t i = 0; i < 4 && rem--; i++) { - extend_table(o_head, &o_tail, (oks >>= 1) & 1, - LF_POLY_EVEN << 1 | 1, LF_POLY_ODD << 1, 0); + 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) & 1, - LF_POLY_ODD, LF_POLY_EVEN << 1 | 1, (in >>= 2) & 3); + 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; } - bucket_sort_intersect(e_head, e_tail, o_head, o_tail, &bucket_info, bucket); for (int i = bucket_info.numbuckets - 1; i >= 0; i--) { @@ -228,7 +220,6 @@ 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) @@ -238,6 +229,8 @@ struct Crypto1State* lfsr_recovery32(uint32_t ks2, uint32_t in) 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; @@ -253,7 +246,6 @@ struct Crypto1State* lfsr_recovery32(uint32_t ks2, uint32_t in) } - // 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; @@ -261,22 +253,15 @@ 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); // Byte swapping - + in = (in >> 16 & 0xff) | (in << 16) | (in & 0xff00); recover(odd_head, odd_tail, oks, even_head, even_tail, eks, 11, statelist, in << 1, bucket); - out: free(odd_head); free(even_head); @@ -324,12 +309,12 @@ struct Crypto1State* lfsr_recovery64(uint32_t ks2, uint32_t ks3) sl->odd = sl->even = 0; for(i = 30; i >= 0; i -= 2) { - oks[i >> 1] = BIT(ks2, i ^ 24); - oks[16 + (i >> 1)] = BIT(ks3, i ^ 24); + oks[i >> 1] = BEBIT(ks2, i); + oks[16 + (i >> 1)] = BEBIT(ks3, i); } for(i = 31; i >= 0; i -= 2) { - eks[i >> 1] = BIT(ks2, i ^ 24); - eks[16 + (i >> 1)] = BIT(ks3, i ^ 24); + eks[i >> 1] = BEBIT(ks2, i); + eks[16 + (i >> 1)] = BEBIT(ks3, i); } for(i = 0xfffff; i >= 0; --i) { @@ -380,41 +365,44 @@ struct Crypto1State* lfsr_recovery64(uint32_t ks2, uint32_t ks3) /** lfsr_rollback_bit * Rollback the shift register in order to get previous states */ -void lfsr_rollback_bit(struct Crypto1State *s, uint32_t in, int fb) +uint8_t lfsr_rollback_bit(struct Crypto1State *s, uint32_t in, int fb) { int out; - uint32_t tmp; - + uint8_t ret; + uint32_t t; + s->odd &= 0xffffff; - tmp = s->odd; - s->odd = s->even; - s->even = tmp; + t = s->odd, s->odd = s->even, s->even = t; out = s->even & 1; out ^= LF_POLY_EVEN & (s->even >>= 1); out ^= LF_POLY_ODD & s->odd; out ^= !!in; - out ^= filter(s->odd) & !!fb; + 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 */ -void lfsr_rollback_byte(struct Crypto1State *s, uint32_t in, int fb) +uint8_t lfsr_rollback_byte(struct Crypto1State *s, uint32_t in, int fb) { - int i; + int i, ret=0; for (i = 7; i >= 0; --i) - lfsr_rollback_bit(s, BEBIT(in, i), fb); + 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 */ -void lfsr_rollback_word(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) - lfsr_rollback_bit(s, BEBIT(in, i), fb); + ret |= lfsr_rollback_bit(s, BEBIT(in, i), fb) << (i ^ 24); + return ret; } /** nonce_distance @@ -440,115 +428,80 @@ int nonce_distance(uint32_t from, uint32_t to) 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 4 last bits of Nr + * 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 *candidates = malloc(4 << 21); - uint32_t c, entry; - int size, i; - + uint32_t c, entry, *candidates = malloc(4 << 10); + int i, size = 0, good; + if(!candidates) return 0; - size = (1 << 21) - 1; - for(i = 0; i <= size; ++i) - candidates[i] = i; - - for(c = 0; c < 8; ++c) - for(i = 0;i <= size; ++i) { - entry = candidates[i] ^ fastfwd[isodd][c]; - - if(filter(entry >> 1) == BIT(ks[c], isodd)) - if(filter(entry) == BIT(ks[c], isodd + 2)) - continue; - - candidates[i--] = candidates[size--]; + 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)); } - - candidates[size + 1] = -1; + if(good) + candidates[size++] = i; + } + + candidates[size] = -1; return candidates; } -/** brute_top +/** check_pfx_parity * helper function which eliminates possible secret states using parity bits */ static struct Crypto1State* -brute_top(uint32_t prefix, uint32_t rresp, unsigned char parities[8][8], - uint32_t odd, uint32_t even, struct Crypto1State* sl) +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 no_par) { - struct Crypto1State s; - uint32_t ks1, nr, ks2, rr, ks3, good, c; - - bool no_par = true; - for (int i = 0; i < 8; i++) { - for (int j = 0; j < 8; j++) { - if (parities[i][j] != 0) { - no_par = false; - break; - } - } - } + uint32_t ks1, nr, ks2, rr, ks3, c, good = 1; - for(c = 0; c < 8; ++c) { - s.odd = odd ^ fastfwd[1][c]; - s.even = even ^ fastfwd[0][c]; + for(c = 0; good && c < 8; ++c) { + sl->odd = odd ^ fastfwd[1][c]; + sl->even = even ^ fastfwd[0][c]; - lfsr_rollback_bit(&s, 0, 0); - lfsr_rollback_bit(&s, 0, 0); - lfsr_rollback_bit(&s, 0, 0); + lfsr_rollback_bit(sl, 0, 0); + lfsr_rollback_bit(sl, 0, 0); - lfsr_rollback_word(&s, 0, 0); - lfsr_rollback_word(&s, prefix | c << 5, 1); - - sl->odd = s.odd; - sl->even = s.even; + ks3 = lfsr_rollback_bit(sl, 0, 0); + ks2 = lfsr_rollback_word(sl, 0, 0); + ks1 = lfsr_rollback_word(sl, prefix | c << 5, 1); if (no_par) break; - ks1 = crypto1_word(&s, prefix | c << 5, 1); - ks2 = crypto1_word(&s,0,0); - ks3 = crypto1_word(&s, 0,0); nr = ks1 ^ (prefix | c << 5); rr = ks2 ^ rresp; - good = 1; 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] ^ BIT(ks3, 24); - - if(!good) - return sl; + good &= parity(rr & 0x000000ff) ^ parities[c][7] ^ ks3; } - return ++sl; + return sl + good; } /** lfsr_common_prefix * Implentation of the common prefix attack. - * Requires the 28 bit constant prefix used as reader nonce (pfx) - * The reader response used (rr) - * The keystream used to encrypt the observed NACK's (ks) - * The parity bits (par) - * It returns a zero terminated list of possible cipher states after the - * tag nonce was fed in */ struct Crypto1State* -lfsr_common_prefix(uint32_t pfx, uint32_t rr, uint8_t ks[8], uint8_t par[8][8]) +lfsr_common_prefix(uint32_t pfx, uint32_t rr, uint8_t ks[8], uint8_t par[8][8], uint32_t no_par) { struct Crypto1State *statelist, *s; uint32_t *odd, *even, *o, *e, top; @@ -556,29 +509,24 @@ lfsr_common_prefix(uint32_t pfx, uint32_t rr, uint8_t ks[8], uint8_t par[8][8]) odd = lfsr_prefix_ks(ks, 1); even = lfsr_prefix_ks(ks, 0); - statelist = malloc((sizeof *statelist) << 21); //how large should be? - if(!statelist || !odd || !even) - { - free(statelist); - free(odd); - free(even); - return 0; + s = statelist = malloc((sizeof *statelist) << 22); // was << 20. Need more for no_par special attack. Enough??? + if(!s || !odd || !even) { + free(statelist); + statelist = 0; + goto out; } - s = statelist; - for(o = odd; *o != -1; ++o) - for(e = even; *e != -1; ++e) + for(o = odd; *o + 1; ++o) + for(e = even; *e + 1; ++e) for(top = 0; top < 64; ++top) { - *o = (*o & 0x1fffff) | (top << 21); - *e = (*e & 0x1fffff) | (top >> 3) << 21; - s = brute_top(pfx, rr, par, *o, *e, s); + *o += 1 << 21; + *e += (!(top & 7) + 1) << 21; + s = check_pfx_parity(pfx, rr, par, *o, *e, s, no_par); } - s->odd = s->even = -1; - //printf("state count = %d\n",s-statelist); - + s->odd = s->even = 0; +out: free(odd); free(even); - return statelist; }