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/>.
32 #define ROTL(a) (((a)<<1)|((a)>>7))
39 static const uint8_t fg_table[] = {
40 0xfa, 0xd6, 0xb0, 0xb2, 0x7b, 0x5e, 0x71, 0x78,
41 0xed, 0xd4, 0xa5, 0xb3, 0xef, 0xdc, 0xe7, 0xf9
46 a ^= fg_table[a&0xf]&0xf0;
47 a ^= fg_table[a>>4] &0x0f;
48 a ^= fg_table[a&0xf]&0xf0;
55 #include "cscipher_sbox.h"
56 #define P(a) (cscipher_sbox[(a)])
59 static const uint8_t round_const[] = {
60 0xb7, 0xe1, 0x51, 0x62, 0x8a, 0xed, 0x2a, 0x6a,
61 0xbf, 0x71, 0x58, 0x80, 0x9c, 0xf4, 0xf3, 0xc7 };
63 static const uint8_t ks_const[] = {
64 0x29,0x0d,0x61,0x40,0x9c,0xeb,0x9e,0x8f,
65 0x1f,0x85,0x5f,0x58,0x5b,0x01,0x39,0x86,
66 0x97,0x2e,0xd7,0xd6,0x35,0xae,0x17,0x16,
67 0x21,0xb6,0x69,0x4e,0xa5,0x72,0x87,0x08,
68 0x3c,0x18,0xe6,0xe7,0xfa,0xad,0xb8,0x89,
69 0xb7,0x00,0xf7,0x6f,0x73,0x84,0x11,0x63,
70 0x3f,0x96,0x7f,0x6e,0xbf,0x14,0x9d,0xac,
71 0xa4,0x0e,0x7e,0xf6,0x20,0x4a,0x62,0x30,
72 0x03,0xc5,0x4b,0x5a,0x46,0xa3,0x44,0x65
75 static uint16_t m(uint16_t a){
76 uint8_t xl, xr, yl, yr;
80 yl = (ROTL(xl)&0x55)^xl^xr;
82 ret = (P(yr)<<8)|P(yl);
86 static uint16_t m_inv(uint16_t a){
91 xl ^= (ROTL(xl)&0xaa);
97 void cscipher_enc(void* buffer, const cscipher_ctx_t* ctx){
102 cli_putstr("\r\nDBG: round ");
104 cli_putstr(" buffer:");
105 cli_hexdump(buffer, 8);
109 memxor(buffer, ctx->keys[i], 8);
111 memxor(buffer, round_const+((j==1)?0:8), 8);
114 ((uint16_t*)tmp)[k] = m(((uint16_t*)buffer)[k]);
117 ((uint8_t*)buffer)[k] = tmp[2*k];
118 ((uint8_t*)buffer)[k+4] = tmp[2*k+1];
122 memxor(buffer, ctx->keys[8], 8);
125 void cscipher_dec(void* buffer, const cscipher_ctx_t* ctx){
128 memxor(buffer, ctx->keys[8], 8);
132 tmp[2*k] = ((uint8_t*)buffer)[k];
133 tmp[2*k+1] = ((uint8_t*)buffer)[4+k];
136 ((uint16_t*)buffer)[k] = m_inv(((uint16_t*)tmp)[k]);
139 memxor(buffer, ctx->keys[i], 8);
141 memxor(buffer, round_const+((j==1)?0:8), 8);
148 void cscipher_init(const void* key, cscipher_ctx_t* ctx){
149 uint8_t tmp_key[16], tmp[8];
151 memcpy(tmp_key, key, 16);
154 cli_putstr("\r\nDBG: round ");
156 cli_putstr(" key state:");
157 cli_hexdump(tmp_key, 16);
159 memcpy(tmp, tmp_key+(((i&1)==0)?0:8), 8);
160 memxor(tmp, ks_const+8*i, 8);
170 tmp_key[j+(((i&1)==0)?8:0)] ^= t;
172 memcpy(ctx->keys[i], tmp_key+(((i&1)==0)?8:0), 8);