--- /dev/null
+/* serpent-sboxes.c */
+/*
+ This file is part of the AVR-Crypto-Lib.
+ Copyright (C) 2008 Daniel Otte (daniel.otte@rub.de)
+
+ 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 3 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, see <http://www.gnu.org/licenses/>.
+*/
+/* serpent-sboxes.c
+ * a non-bitsliced implementation of the serpent sboxes
+ * author: Daniel Otte
+ * email: daniel.otte@rub.de
+ * license: GPLv3
+ */
+
+#include <stdint.h>
+#include <string.h> /* memset() */
+#include <avr/pgmspace.h>
+#include "serpent-sboxes.h"
+
+uint8_t sbox[] PROGMEM = {
+ 0x38, 0xF1, 0xA6, 0x5B, 0xED, 0x42, 0x70, 0x9C,
+ 0xFC, 0x27, 0x90, 0x5A, 0x1B, 0xE8, 0x6D, 0x34,
+ 0x86, 0x79, 0x3C, 0xAF, 0xD1, 0xE4, 0x0B, 0x52,
+ 0x0F, 0xB8, 0xC9, 0x63, 0xD1, 0x24, 0xA7, 0x5E,
+ 0x1F, 0x83, 0xC0, 0xB6, 0x25, 0x4A, 0x9E, 0x7D,
+ 0xF5, 0x2B, 0x4A, 0x9C, 0x03, 0xE8, 0xD6, 0x71,
+ 0x72, 0xC5, 0x84, 0x6B, 0xE9, 0x1F, 0xD3, 0xA0,
+ 0x1D, 0xF0, 0xE8, 0x2B, 0x74, 0xCA, 0x93, 0x56,
+/* now the inverted sboxes */
+ 0xD3, 0xB0, 0xA6, 0x5C, 0x1E, 0x47, 0xF9, 0x82,
+ 0x58, 0x2E, 0xF6, 0xC3, 0xB4, 0x79, 0x1D, 0xA0,
+ 0xC9, 0xF4, 0xBE, 0x12, 0x03, 0x6D, 0x58, 0xA7,
+ 0x09, 0xA7, 0xBE, 0x6D, 0x35, 0xC2, 0x48, 0xF1,
+ 0x50, 0x83, 0xA9, 0x7E, 0x2C, 0xB6, 0x4F, 0xD1,
+ 0x8F, 0x29, 0x41, 0xDE, 0xB6, 0x53, 0x7C, 0xA0,
+ 0xFA, 0x1D, 0x53, 0x60, 0x49, 0xE7, 0x2C, 0x8B,
+ 0x30, 0x6D, 0x9E, 0xF8, 0x5C, 0xB7, 0xA1, 0x42
+};
+
+
+#define SHR_O(a) c=(a)&1; ((a) = (a)>>1)
+#define SHR_I(a) ((a) = (c?0x80:0x00)| ((a)>>1))
+
+static void serpent_ip(uint32_t *i, uint8_t *o){
+ uint8_t c; // carry
+ uint8_t n,m;
+ memset(o, 0, 16);
+ for(n=0; n<16; ++n){
+ for(m=0; m<2; ++m){
+ SHR_O(i[0]);
+ SHR_I(o[n]);
+ SHR_O(i[1]);
+ SHR_I(o[n]);
+ SHR_O(i[2]);
+ SHR_I(o[n]);
+ SHR_O(i[3]);
+ SHR_I(o[n]);
+ }
+ }
+}
+
+#undef SHR_I
+#define SHR_I(a) ((a) = (c?0x80000000L:0x00L)| ((a)>>1)) /* we use 32-bit words here */
+
+static void serpent_fp(uint32_t *i, uint32_t *o){
+ uint8_t c; // carry
+ uint8_t n,m;
+ memset(o, 0, 16);
+ for(n=0; n<4; ++n){
+ for(m=0; m<8; ++m){
+ SHR_O(i[n]);
+ SHR_I(o[0]);
+ SHR_O(i[n]);
+ SHR_I(o[1]);
+ SHR_O(i[n]);
+ SHR_I(o[2]);
+ SHR_O(i[n]);
+ SHR_I(o[3]);
+ }
+ }
+}
+
+/******************************************************************************/
+static void sbox128x(uint8_t box, void* w){
+ uint8_t sb[16];
+ uint8_t i,t,x;
+ box &= 0x0f;
+ /* load sbox */
+ for(i=0; i<8; ++i){
+ t = pgm_read_byte(sbox + box*8 + i);
+ sb[2*i+0]=t>>4;
+ sb[2*i+1]=t&0xf;
+ }
+ uint8_t o[16];
+ serpent_ip(w,o);
+
+ for(i=0; i<16; ++i){
+ t = ((uint8_t*)o)[i];
+ x = sb[t>>4];
+ x <<= 4;
+ x |= sb[t&0xf];
+ ((uint8_t*)o)[i] = x;
+ }
+ serpent_fp((uint32_t*)o, w);
+}
+
+void sbox128(void * w, uint8_t box){
+ sbox128x(box&0x7, w);
+}
+
+
+void inv_sbox128(void * w, uint8_t box){
+ sbox128x(((box&0x7)|0x8), w);
+}
+
+
+