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
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){
77 uint8_t xl, xr, yl, yr;
81 yl = (ROTL(xl)&0x55)^xl^xr;
83 ret = (P(yr)<<8)|P(yl);
87 static uint16_t m_inv(uint16_t a){
92 xl ^= (ROTL(xl)&0xaa);
98 void cscipher_enc(void* buffer, const cscipher_ctx_t* ctx){
103 cli_putstr_P(PSTR("\r\nDBG: round "));
105 cli_putstr_P(PSTR(" buffer:"));
106 cli_hexdump(buffer, 8);
110 memxor(buffer, ctx->keys[i], 8);
112 memxor_P(buffer, round_const+((j==1)?0:8), 8);
115 ((uint16_t*)tmp)[k] = m(((uint16_t*)buffer)[k]);
118 ((uint8_t*)buffer)[k] = tmp[2*k];
119 ((uint8_t*)buffer)[k+4] = tmp[2*k+1];
123 memxor(buffer, ctx->keys[8], 8);
126 void cscipher_dec(void* buffer, const cscipher_ctx_t* ctx){
129 memxor(buffer, ctx->keys[8], 8);
133 tmp[2*k] = ((uint8_t*)buffer)[k];
134 tmp[2*k+1] = ((uint8_t*)buffer)[4+k];
137 ((uint16_t*)buffer)[k] = m_inv(((uint16_t*)tmp)[k]);
140 memxor(buffer, ctx->keys[i], 8);
142 memxor_P(buffer, round_const+((j==1)?0:8), 8);
149 void cscipher_init(const void* key, cscipher_ctx_t* ctx){
150 uint8_t tmp_key[16], tmp[8];
152 memcpy(tmp_key, key, 16);
155 cli_putstr_P(PSTR("\r\nDBG: round "));
157 cli_putstr_P(PSTR(" key state:"));
158 cli_hexdump(tmp_key, 16);
160 memcpy(tmp, tmp_key+(((i&1)==0)?0:8), 8);
161 memxor_P(tmp, ks_const+8*i, 8);
171 tmp_key[j+(((i&1)==0)?8:0)] ^= t;
173 memcpy(ctx->keys[i], tmp_key+(((i&1)==0)?8:0), 8);