1 /* cscipher_small_core.c */
3 This file is part of the ARM-Crypto-Lib.
4 Copyright (C) 2006-2010 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 #include <avr/pgmspace.h>
33 #define ROTL(a) (((a)<<1)|((a)>>7))
40 static const uint8_t fg_table[] PROGMEM = {
41 0xfa, 0xd6, 0xb0, 0xb2, 0x7b, 0x5e, 0x71, 0x78,
42 0xed, 0xd4, 0xa5, 0xb3, 0xef, 0xdc, 0xe7, 0xf9
46 uint8_t p(uint8_t a) {
47 a ^= pgm_read_byte(fg_table+(a&0xf))&0xf0;
48 a ^= pgm_read_byte(fg_table+(a>>4)) &0x0f;
49 a ^= pgm_read_byte(fg_table+(a&0xf))&0xf0;
56 #include "cscipher_sbox.h"
57 #define P(a) pgm_read_byte(cscipher_sbox+(a))
60 static const uint8_t round_const[] PROGMEM = {
61 0xb7, 0xe1, 0x51, 0x62, 0x8a, 0xed, 0x2a, 0x6a,
62 0xbf, 0x71, 0x58, 0x80, 0x9c, 0xf4, 0xf3, 0xc7 };
64 static const uint8_t ks_const[] PROGMEM = {
65 0x29, 0x0d, 0x61, 0x40, 0x9c, 0xeb, 0x9e, 0x8f,
66 0x1f, 0x85, 0x5f, 0x58, 0x5b, 0x01, 0x39, 0x86,
67 0x97, 0x2e, 0xd7, 0xd6, 0x35, 0xae, 0x17, 0x16,
68 0x21, 0xb6, 0x69, 0x4e, 0xa5, 0x72, 0x87, 0x08,
69 0x3c, 0x18, 0xe6, 0xe7, 0xfa, 0xad, 0xb8, 0x89,
70 0xb7, 0x00, 0xf7, 0x6f, 0x73, 0x84, 0x11, 0x63,
71 0x3f, 0x96, 0x7f, 0x6e, 0xbf, 0x14, 0x9d, 0xac,
72 0xa4, 0x0e, 0x7e, 0xf6, 0x20, 0x4a, 0x62, 0x30,
73 0x03, 0xc5, 0x4b, 0x5a, 0x46, 0xa3, 0x44, 0x65
76 static uint16_t m(uint16_t a)
78 uint8_t xl, xr, yl, yr;
82 yl = (ROTL(xl) & 0x55) ^ xl ^ xr;
84 ret = (P(yr) << 8) | P(yl);
88 static uint16_t m_inv(uint16_t a)
94 xl ^= (ROTL(xl) & 0xaa);
96 return (xr << 8) | xl;
99 void cscipher_enc(void *buffer, const cscipher_ctx_t *ctx)
103 for (i = 0; i < 8; ++i) {
105 cli_putstr_P(PSTR("\r\nDBG: round "));
107 cli_putstr_P(PSTR(" buffer:"));
108 cli_hexdump(buffer, 8);
110 for (j = 0; j < 3; ++j) {
112 memxor(buffer, ctx->keys[i], 8);
114 memxor_P(buffer, round_const + ((j == 1) ? 0 : 8), 8);
116 for (k = 0; k < 4; ++k) {
117 ((uint16_t*) tmp)[k] = m(((uint16_t*) buffer)[k]);
119 for (k = 0; k < 4; ++k) {
120 ((uint8_t*) buffer)[k] = tmp[2 * k];
121 ((uint8_t*) buffer)[k + 4] = tmp[2 * k + 1];
125 memxor(buffer, ctx->keys[8], 8);
128 void cscipher_dec(void *buffer, const cscipher_ctx_t *ctx)
132 memxor(buffer, ctx->keys[8], 8);
134 for (j = 0; j < 3; ++j) {
135 for (k = 0; k < 4; ++k) {
136 tmp[2 * k] = ((uint8_t*) buffer)[k];
137 tmp[2 * k + 1] = ((uint8_t*) buffer)[4 + k];
139 for (k = 0; k < 4; ++k) {
140 ((uint16_t*) buffer)[k] = m_inv(((uint16_t*) tmp)[k]);
143 memxor(buffer, ctx->keys[i], 8);
145 memxor_P(buffer, round_const + ((j == 1) ? 0 : 8), 8);
152 void cscipher_init(const void *key, cscipher_ctx_t *ctx)
154 uint8_t tmp_key[16], tmp[8];
155 uint8_t i, j, k, t = 0;
156 memcpy(tmp_key, key, 16);
157 for (i = 0; i < 9; ++i) {
159 cli_putstr_P(PSTR("\r\nDBG: round "));
161 cli_putstr_P(PSTR(" key state:"));
162 cli_hexdump(tmp_key, 16);
164 memcpy(tmp, tmp_key + (((i & 1) == 0) ? 0 : 8), 8);
165 memxor_P(tmp, ks_const + 8 * i, 8);
166 for (j = 0; j < 8; ++j) {
169 for (j = 0; j < 8; ++j) {
170 for (k = 0; k < 8; ++k) {
175 tmp_key[j + (((i & 1) == 0) ? 8 : 0)] ^= t;
177 memcpy(ctx->keys[i], tmp_key + (((i & 1) == 0) ? 8 : 0), 8);