3 This file is part of the AVR-Crypto-Lib.
4 Copyright (C) 2008 Daniel Otte (daniel.otte@rub.de)
6 This program is free software: you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation, either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
21 * a implementation of the PRESENT block-cipher
23 * email: daniel.otte@rub.de
31 #include <avr/pgmspace.h>
33 uint8_t present_sbox(uint8_t b){
34 static const uint8_t sb[] PROGMEM = {
40 return (pgm_read_byte(&sb[b >> 4]) << 4) | pgm_read_byte(&sb[b & 0xf]);
43 uint8_t present_sbox_inv(uint8_t b){
44 static const uint8_t sb[] PROGMEM = {
50 return (pgm_read_byte(&sb[b >> 4]) << 4) | pgm_read_byte(&sb[b & 0xf]);
53 void present_p(uint8_t *o, uint8_t *i){
70 void present_generic_enc(void *buffer, uint8_t *ctx, uint8_t ksize_B,
71 void(*update)(uint8_t*, uint8_t)){
72 uint8_t i,j,tmp[8], k[ksize_B];
73 memcpy(k, ctx, ksize_B);
78 tmp[j] = present_sbox(((uint8_t*)buffer)[j]);
80 present_p(buffer, tmp);
86 void present_generic_dec(void *buffer, uint8_t *ctx, uint8_t ksize_B,
87 void(*update)(uint8_t*, uint8_t)){
88 uint8_t j,tmp[8], k[ksize_B];
90 memcpy(k, ctx + ksize_B, ksize_B);
94 present_p(tmp, buffer);
95 present_p(buffer, tmp);
98 ((uint8_t*)buffer)[j] = present_sbox_inv(((uint8_t*)buffer)[j]);
101 memxor(buffer, k, 8);