X-Git-Url: https://git.cryptolib.org/?p=avr-crypto-lib.git;a=blobdiff_plain;f=skipjack%2Fskipjack.c;h=68187ce079222f8684ca276199accebf05c2b46f;hp=07bc97bf9bf3412dd96d62752611ba27a0dd7b85;hb=4b5da1dc27a791b5c448274a3db09cd035b33493;hpb=701cee0d98aab48dd3192c8cc7c77eb42581bc56 diff --git a/skipjack/skipjack.c b/skipjack/skipjack.c index 07bc97b..68187ce 100644 --- a/skipjack/skipjack.c +++ b/skipjack/skipjack.c @@ -1,7 +1,7 @@ /* skipjack.c */ /* This file is part of the AVR-Crypto-Lib. - Copyright (C) 2008 Daniel Otte (daniel.otte@rub.de) + Copyright (C) 2006-2015 Daniel Otte (bg@nerilex.org) 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 @@ -31,9 +31,9 @@ #include #if NESSIE_COMPAT -#define SKIPJACK_CNT_BIG 0 -#else #define SKIPJACK_CNT_BIG 1 +#else +#define SKIPJACK_CNT_BIG 0 #endif #if SKIPJACK_CNT_BIG @@ -80,74 +80,80 @@ const uint8_t skipjack_ftable[] PROGMEM ={ }; /*****************************************************************************/ +static +uint16_t skipjack_sub_g(uint8_t g, uint8_t k, uint8_t *key){ + return pgm_read_byte(&(skipjack_ftable[g ^ key[9 - k % 10]])); +} +static uint16_t skipjack_g(uint16_t g, uint8_t k, uint8_t *key){ - #define G1 (((uint8_t*)&g)[0]) - #define G2 (((uint8_t*)&g)[1]) + #define G1 (((uint8_t*)&g)[1]) + #define G2 (((uint8_t*)&g)[0]) /* this could also be rolled up */ - G1 ^= pgm_read_byte_near(&(skipjack_ftable[G2 ^ key[(4*k+0)%10]])); - G2 ^= pgm_read_byte_near(&(skipjack_ftable[G1 ^ key[(4*k+1)%10]])); - G1 ^= pgm_read_byte_near(&(skipjack_ftable[G2 ^ key[(4*k+2)%10]])); - G2 ^= pgm_read_byte_near(&(skipjack_ftable[G1 ^ key[(4*k+3)%10]])); + k *= 4; + G1 ^= skipjack_sub_g(G2, k + 0, key); + G2 ^= skipjack_sub_g(G1, k + 1, key); + G1 ^= skipjack_sub_g(G2, k + 2, key); + G2 ^= skipjack_sub_g(G1, k + 3, key); return g; } /*****************************************************************************/ - +static uint16_t skipjack_g_inv(uint16_t g, uint8_t k, uint8_t *key){ // #define G1 (((uint8_t)&g)[1]) // #define G2 (((uint8_t)&g)[0]) /* this could also be rolled up */ - G2 ^= pgm_read_byte_near(&(skipjack_ftable[G1 ^ key[(4*k+3)%10]])); - G1 ^= pgm_read_byte_near(&(skipjack_ftable[G2 ^ key[(4*k+2)%10]])); - G2 ^= pgm_read_byte_near(&(skipjack_ftable[G1 ^ key[(4*k+1)%10]])); - G1 ^= pgm_read_byte_near(&(skipjack_ftable[G2 ^ key[(4*k+0)%10]])); - return g; + k *= 4; + G2 ^= skipjack_sub_g(G1, k + 3, key); + G1 ^= skipjack_sub_g(G2, k + 2, key); + G2 ^= skipjack_sub_g(G1, k + 1, key); + G1 ^= skipjack_sub_g(G2, k + 0, key); + return g; } /*****************************************************************************/ - -void skipjack_a(uint16_t* w, uint8_t k, uint8_t* key){ +static +void skipjack_a(uint16_t *w, uint8_t k, uint8_t *key){ uint16_t t; - - t = w[3]; - w[3] = w[2]; - w[2] = w[1]; - w[1] = skipjack_g(w[0],k-1,key); - w[0] = t ^ w[1] ^ (((uint16_t)k)SKIPJACK_CNT_SHIFT); + t = w[0]; + w[0] = w[1]; + w[1] = w[2]; + w[2] = skipjack_g(w[3],k,key); + w[3] = t ^ w[2] ^ (((uint16_t)k+1)SKIPJACK_CNT_SHIFT); } /*****************************************************************************/ - -void skipjack_a_inv(uint16_t* w, uint8_t k, uint8_t* key){ +static +void skipjack_a_inv(uint16_t *w, uint8_t k, uint8_t *key){ uint16_t t; - t = w[0] ^ w[1]; - w[0] = skipjack_g_inv(w[1],k-1,key); - w[1] = w[2]; - w[2] = w[3]; - w[3] = t ^ (((uint16_t)k)SKIPJACK_CNT_SHIFT); + t = w[3] ^ w[2]; + w[3] = skipjack_g_inv(w[2],k,key); + w[2] = w[1]; + w[1] = w[0]; + w[0] = t ^ (((uint16_t)k+1)SKIPJACK_CNT_SHIFT); } /*****************************************************************************/ - -void skipjack_b(uint16_t* w, uint8_t k, uint8_t* key){ +static +void skipjack_b(uint16_t *w, uint8_t k, uint8_t *key){ uint16_t t; - t = w[0]; - w[0] = w[3]; - w[3] = w[2]; - w[2] = t ^ (((uint16_t)k)SKIPJACK_CNT_SHIFT) ^ w[1]; - w[1] = skipjack_g(t,k-1,key); + t = w[3]; + w[3] = w[0]; + w[0] = w[1]; + w[1] = t ^ (((uint16_t)k+1)SKIPJACK_CNT_SHIFT) ^ w[2]; + w[2] = skipjack_g(t,k,key); } /*****************************************************************************/ - -void skipjack_b_inv(uint16_t* w, uint8_t k, uint8_t* key){ +static +void skipjack_b_inv(uint16_t *w, uint8_t k, uint8_t *key){ uint16_t t; - t = w[2]; - w[2] = w[3]; - w[3] = w[0]; - w[0] = skipjack_g_inv(w[1],k-1,key); - w[1] = w[0] ^ t ^ (((uint16_t)k)SKIPJACK_CNT_SHIFT); + t = w[1]; + w[1] = w[0]; + w[0] = w[3]; + w[3] = skipjack_g_inv(w[2],k,key); + w[2] = w[3] ^ t ^ (((uint16_t)k+1)SKIPJACK_CNT_SHIFT); } /*****************************************************************************/ @@ -155,29 +161,28 @@ void skipjack_b_inv(uint16_t* w, uint8_t k, uint8_t* key){ * block is 64 bits (=8 bytes) in size, key is 80 bits (=10 bytes) in size. * */ -void skipjack_enc(void* block, void* key){ +void skipjack_enc(void *block, void *key){ uint8_t k; for(k=0; k<32; ++k){ if(k & 0x08){ - skipjack_b((uint16_t*)block, k+1, key); + skipjack_b((uint16_t*)block, k, key); } else { - skipjack_a((uint16_t*)block, k+1, key); + skipjack_a((uint16_t*)block, k, key); } } } - /*****************************************************************************/ /** * block is 64 bits (=8 bytes) in size, key is 80 bits (=10 bytes) in size. * */ -void skipjack_dec(void* block, void* key){ +void skipjack_dec(void *block, void *key){ int8_t k; for(k=31; k>=0; --k){ if(k & 0x08){ - skipjack_b_inv((uint16_t*)block, k+1, key); + skipjack_b_inv((uint16_t*)block, k, key); } else { - skipjack_a_inv((uint16_t*)block, k+1, key); + skipjack_a_inv((uint16_t*)block, k, key); } } }