From 417f4ae12711f28d8b27dcd29786a1cc9300aaad Mon Sep 17 00:00:00 2001 From: iceman1001 Date: Tue, 19 Jan 2016 16:19:59 +0100 Subject: [PATCH] CHG: Crapto1 v3.3 for the ARMSRC --- armsrc/crapto1.c | 51 ++++++++++++++++++++++++++---------------------- armsrc/crapto1.h | 5 ++++- armsrc/crypto1.c | 2 -- 3 files changed, 32 insertions(+), 26 deletions(-) diff --git a/armsrc/crapto1.c b/armsrc/crapto1.c index 87213757..4b4e240e 100644 --- a/armsrc/crapto1.c +++ b/armsrc/crapto1.c @@ -33,8 +33,7 @@ static void __attribute__((constructor)) fill_lut() static void quicksort(uint32_t* const start, uint32_t* const stop) { - uint32_t *it = start + 1, *rit = stop; - uint32_t tmp; + uint32_t *it = start + 1, *rit = stop, t; if(it > rit) return; @@ -44,19 +43,13 @@ static void quicksort(uint32_t* const start, uint32_t* const stop) ++it; else if(*rit > *start) --rit; - else { - tmp = *it; - *it = *rit; - *rit = tmp; - } + else + t = *it, *it = *rit, *rit = t; if(*rit >= *start) --rit; - if(rit != start) { - tmp = *rit; - *rit = *start; - *start = tmp; - } + if(rit != start) + t = *rit, *rit = *start, *start = t; quicksort(start, rit - 1); quicksort(rit + 1, stop); @@ -325,12 +318,10 @@ uint8_t lfsr_rollback_bit(struct Crypto1State *s, uint32_t in, int fb) { int out; uint8_t ret; - uint32_t tmp; + 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); @@ -346,7 +337,8 @@ 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) { -/* int i, ret = 0; + /* + int i, ret = 0; for (i = 7; i >= 0; --i) ret |= lfsr_rollback_bit(s, BIT(in, i), fb) << i; */ @@ -367,7 +359,8 @@ 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; + /* + int i; uint32_t ret = 0; for (i = 31; i >= 0; --i) ret |= lfsr_rollback_bit(s, BEBIT(in, i), fb) << (i ^ 24); @@ -435,6 +428,8 @@ 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 @@ -444,10 +439,12 @@ static uint32_t fastfwd[2][8] = { * 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 */ + // TO VERIFY 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; @@ -503,6 +500,12 @@ check_pfx_parity(uint32_t prefix, uint32_t rresp, uint8_t parities[8][8], /** 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]) @@ -516,8 +519,9 @@ lfsr_common_prefix(uint32_t pfx, uint32_t rr, uint8_t ks[8], uint8_t par[8][8]) s = statelist = malloc((sizeof *statelist) << 20); if(!s || !odd || !even) { free(statelist); - statelist = 0; - goto out; + free(odd); + free(even); + return 0; } for(o = odd; *o + 1; ++o) @@ -529,8 +533,9 @@ lfsr_common_prefix(uint32_t pfx, uint32_t rr, uint8_t ks[8], uint8_t par[8][8]) } s->odd = s->even = 0; -out: + free(odd); free(even); + return statelist; } diff --git a/armsrc/crapto1.h b/armsrc/crapto1.h index b144853c..50654db9 100644 --- a/armsrc/crapto1.h +++ b/armsrc/crapto1.h @@ -15,7 +15,7 @@ Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, US$ - Copyright (C) 2008-2008 bla + Copyright (C) 2008-2014 bla */ #ifndef CRAPTO1_INCLUDED #define CRAPTO1_INCLUDED @@ -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;\ diff --git a/armsrc/crypto1.c b/armsrc/crypto1.c index db864113..b218af19 100644 --- a/armsrc/crypto1.c +++ b/armsrc/crypto1.c @@ -20,8 +20,6 @@ #include "crapto1.h" #include -#define SWAPENDIAN(x)\ - (x = (x >> 8 & 0xff00ff) | (x & 0xff00ff) << 8, x = x >> 16 | x << 16) void crypto1_create(struct Crypto1State *s, uint64_t key) { -- 2.39.5