X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ian/git?p=secnet.git;a=blobdiff_plain;f=serpent.c;h=7c5850535f24f87655f2508b0c4045f89e3dcd9a;hp=ce918547155015ea7981c9ed51b87b345e9e1619;hb=HEAD;hpb=1caa23ff879cec7f8f36b32a987f0610291ef177 diff --git a/serpent.c b/serpent.c index ce91854..a8bfe2a 100644 --- a/serpent.c +++ b/serpent.c @@ -1,41 +1,109 @@ /* - * This file is - * Copyright (C) 1998 Ross Anderson, Eli Biham, Lars Knudsen + * serpent.c: Implementation of the Serpent block cipher + */ +/* + * This file is Free Software. It has been modified to as part of its + * incorporation into secnet. + * + * Copyright 1998 Ross Anderson, Eli Biham, Lars Knudsen + * Copyright 1995-2001 Stephen Early + * Copyright 2011-2013 Ian Jackson + * + * For more information about Serpent see + * http://www.cl.cam.ac.uk/users/rja14/serpent.html * - * For more information see http://www.cl.cam.ac.uk/users/rja14/serpent.html + * You may redistribute secnet as a whole and/or modify it under the + * terms of the GNU General Public License as published by the Free + * Software Foundation; either version 3, or (at your option) any + * later version. * - * 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, 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + * You may redistribute this file and/or modify it under the terms of + * the GNU General Public License as published by the Free Software + * Foundation; either version 2, or (at your option) any later + * version. * + * This software 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 software; if not, see + * https://www.gnu.org/licenses/gpl.html. */ -#include "secnet.h" +#include +#include "hexdebug.h" #include "serpent.h" #include "serpentsboxes.h" -void serpent_makekey(struct keyInstance *key, int keyLen, - uint8_t *keyMaterial) +#ifdef SERPENT_BIGENDIAN + +#define GETPUT_CP(bytenum) \ + (((basep) + (lenbytes) - (offset) - 4)[(bytenum)]) + +#define SERPENT_DECORATE(func) serpentbe_##func + +#else /* !defined(SERPENT_BIGENDIAN) */ + +#define GETPUT_CP(bytenum) \ + (((basep) + (offset))[3-(bytenum)]) + +#define SERPENT_DECORATE(func) serpent_##func + +#endif /* !defined(SERPENT_BIGENDIAN) */ + +#if 0 + +#include + +static void SERP_DEBUG(const char *str1, + const void *ary, int sz, + const char *str2) +{ + fprintf(stderr,"%s",str1); + hexdebug(stderr,ary,sz); + fprintf(stderr,"%s",str2); +} + +#else + +#define SERP_DEBUG(str1,aryv,sz,str2) /*empty*/ + +#endif + + +static uint32_t serpent_get_32bit(const uint8_t *basep, + int lenbytes, int offset) +{ + return (((uint32_t)GETPUT_CP(0) << 24) | + ((uint32_t)GETPUT_CP(1) << 16) | + ((uint32_t)GETPUT_CP(2) << +8) | + ((uint32_t)GETPUT_CP(3))); +} + +static void serpent_put_32bit(uint8_t *basep, int lenbytes, int offset, uint32_t value) +{ + GETPUT_CP(0) = (char)((value) >> 24); + GETPUT_CP(1) = (char)((value) >> 16); + GETPUT_CP(2) = (char)((value) >> 8); + GETPUT_CP(3) = (char)(value); +} + +void SERPENT_DECORATE(makekey)(struct keyInstance *key, int keyLen, + const uint8_t *keyMaterial) { int i; uint32_t j; uint32_t w[132],k[132]; + SERP_DEBUG("SERPENT makekey ",keyMaterial,keyLen/8,"\n"); + for(i=0; isubkeys[i][j] = k[4*i+j]; } -void serpent_encrypt(struct keyInstance *key, - uint8_t plaintext[16], +void SERPENT_DECORATE(encrypt)(struct keyInstance *key, + const uint8_t plaintext[16], uint8_t ciphertext[16]) { register uint32_t x0, x1, x2, x3; register uint32_t y0, y1, y2, y3; - x0=GET_32BIT_MSB_FIRST(plaintext+12); - x1=GET_32BIT_MSB_FIRST(plaintext+8); - x2=GET_32BIT_MSB_FIRST(plaintext+4); - x3=GET_32BIT_MSB_FIRST(plaintext); + SERP_DEBUG("SERPENT encrypt ",plaintext,16," ->"); + + x0=serpent_get_32bit(plaintext,16,+0); + x1=serpent_get_32bit(plaintext,16,+4); + x2=serpent_get_32bit(plaintext,16,+8); + x3=serpent_get_32bit(plaintext,16,12); /* Start to encrypt the plaintext x */ keying(x0, x1, x2, x3, key->subkeys[ 0]); @@ -197,23 +267,27 @@ void serpent_encrypt(struct keyInstance *key, keying(x0, x1, x2, x3, key->subkeys[32]); /* The ciphertext is now in x */ - PUT_32BIT_MSB_FIRST(ciphertext+12, x0); - PUT_32BIT_MSB_FIRST(ciphertext+8, x1); - PUT_32BIT_MSB_FIRST(ciphertext+4, x2); - PUT_32BIT_MSB_FIRST(ciphertext, x3); + serpent_put_32bit(ciphertext,16,+0, x0); + serpent_put_32bit(ciphertext,16,+4, x1); + serpent_put_32bit(ciphertext,16,+8, x2); + serpent_put_32bit(ciphertext,16,12, x3); + + SERP_DEBUG(" ",ciphertext,16,"\n"); } -void serpent_decrypt(struct keyInstance *key, - uint8_t ciphertext[16], +void SERPENT_DECORATE(decrypt)(struct keyInstance *key, + const uint8_t ciphertext[16], uint8_t plaintext[16]) { register uint32_t x0, x1, x2, x3; register uint32_t y0, y1, y2, y3; - x0=GET_32BIT_MSB_FIRST(ciphertext+12); - x1=GET_32BIT_MSB_FIRST(ciphertext+8); - x2=GET_32BIT_MSB_FIRST(ciphertext+4); - x3=GET_32BIT_MSB_FIRST(ciphertext); + SERP_DEBUG("SERPENT decrypt ",ciphertext,16," ->"); + + x0=serpent_get_32bit(ciphertext,16,+0); + x1=serpent_get_32bit(ciphertext,16,+4); + x2=serpent_get_32bit(ciphertext,16,+8); + x3=serpent_get_32bit(ciphertext,16,12); /* Start to decrypt the ciphertext x */ keying(x0, x1, x2, x3, key->subkeys[32]); @@ -315,8 +389,10 @@ void serpent_decrypt(struct keyInstance *key, keying(x0, x1, x2, x3, key->subkeys[ 0]); /* The plaintext is now in x */ - PUT_32BIT_MSB_FIRST(plaintext+12, x0); - PUT_32BIT_MSB_FIRST(plaintext+8, x1); - PUT_32BIT_MSB_FIRST(plaintext+4, x2); - PUT_32BIT_MSB_FIRST(plaintext, x3); + serpent_put_32bit(plaintext,16,+0, x0); + serpent_put_32bit(plaintext,16,+4, x1); + serpent_put_32bit(plaintext,16,+8, x2); + serpent_put_32bit(plaintext,16,12, x3); + + SERP_DEBUG(" ",plaintext,16,"\n"); }