twister-stub.c

   1 /* twister.c */
   2 /*
   3     This file is part of the Crypto-avr-lib/microcrypt-lib.
   4     Copyright (C) 2008  Daniel Otte (daniel.otte@rub.de)
   5
   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.
  10
  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.
  15
  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/>.
  18 */
  19
  20 #include "config.h"
  21 #include <stdint.h>
  22 #include <string.h>
  23 #include <avr/pgmspace.h>
  24 #include "twister.h"
  25 #include "twister_tables.h"
  26 #include "memxor.h"
  27
  28 #ifndef TWISTER_MUL_TABLE
  29 # include "gf256mul.h"
  30 #endif
  31
  32 #undef DEBUG
  33
  34 #ifdef DEBUG
  35 # include "uart.h"
  36 #endif
  37
  38 #ifdef DEBUG
  39 # define DEBUG_PRINT(ctx, msg) debug_print((ctx), PSTR(msg))
  40 #else
  41 # define DEBUG_PRINT(ctx, msg)
  42 #endif
  43
  44 #ifdef DEBUG
  45
  46 void print_twister_state(twister_state_t* ctx){
  47         uint8_t i;
  48         uart_putstr_P(PSTR("\r\nState:\r\n matrix:\r\n"));
  49         for(i=0; i<8; ++i){
  50                 uart_putstr_P(PSTR("\t[ "));
  51                 uart_hexdump(&(ctx->s[i][0]), 8);
  52                 uart_putstr_P(PSTR("]\r\n"));
  53         }
  54         uart_putstr_P(PSTR("counter: "));
  55         uart_hexdump(&(ctx->counter), 8);
  56
  57         uart_putstr_P(PSTR("\r\nlength_counter_b: "));
  58         uart_hexdump(&(ctx->length_counter_b), 8);
  59         uart_putstr_P(PSTR("\r\n"));
  60 }
  61
  62 void debug_print(twister_state_t* ctx, PGM_P msg){
  63         uart_putstr_P(PSTR("\r\n"));
  64         uart_putstr_P(msg);
  65         print_twister_state(ctx);
  66 }
  67
  68 #endif
  69
  70 static
  71 void shiftrow(void* row, uint8_t shift){
  72         *((uint64_t*)row) = *((uint64_t*)row)>>(8*shift) | *((uint64_t*)row)<<(64-8*shift);
  73 }
  74
  75 #define MDS(a,b)  pgm_read_byte(&(twister_mds[(a)][(b)]))
  76
  77 #ifdef TWISTER_MUL_TABLE
  78 # define MULT(a,b) pgm_read_byte(&(twister_multab[a][b]))
  79 #else
  80 # define MULT(a,b) gf256mul((a),(b), 0x4D)
  81 #endif
  82 void twister_blank_round(twister_state_t* ctx){
  83         uint8_t i,j,k=0;
  84         uint8_t tmp[8][8];
  85         DEBUG_PRINT(ctx, "blank init");
  86         /* add twist counter */
  87         for(i=0; i<8; ++i){
  88                 ctx->s[i][1] ^= ((uint8_t*)&(ctx->counter))[7-i];
  89         }
  90         ctx->counter--;
  91 //      DEBUG_PRINT(ctx, "counter added");
  92         /* sub bytes */
  93         for(i=0; i<8; ++i){
  94                 for(j=0;j<8;++j){
  95                         tmp[i][j] = pgm_read_byte(twister_sbox+ctx->s[i][j]);
  96                 }
  97         }
  98         /* shift rows */
  99 //      for(i=1;i<8; ++i){
 100 //              shiftrow(&(tmp[i][0]), i);
 101 //      }
 102         /* mix columns */
 103         for( i=0; i<8; i++ ){
 104                 // multiply with mds matrix
 105                 for( j=0; j<8; j++ ){
 106                         k=(i+1)&7;
 107                         ctx->s[j][i] =
 108                                 MULT( MDS(j,0), tmp[0][i] ) ^
 109                                 MULT( MDS(j,1), tmp[1][k] ) ^
 110                                 MULT( MDS(j,2), tmp[2][(++k)&7] ) ^
 111                                 MULT( MDS(j,3), tmp[3][(++k)&7] ) ^
 112                                 MULT( MDS(j,4), tmp[4][(++k)&7] ) ^
 113                                 MULT( MDS(j,5), tmp[5][(++k)&7] ) ^
 114                                 MULT( MDS(j,6), tmp[6][(++k)&7] ) ^
 115                                 MULT( MDS(j,7), tmp[7][(++k)&7] ) ;
 116
 117                 }
 118         }
 119         DEBUG_PRINT(ctx, "post MDS");
 120 }
 121
 122 void twister_mini_round(twister_state_t* ctx, void* msg){
 123         /* inject message */
 124         uint8_t i;
 125         for(i=0; i<8; ++i){
 126                 ctx->s[7][7-i] ^= *((uint8_t*)msg);
 127                 msg = (uint8_t*)msg +1;
 128         }
 129         twister_blank_round(ctx);
 130 }
 131 #if 0
 132 void twister_ctx2hash(void* dest, twister_state_t* ctx, uint16_t hashsize_b){
 133         uint8_t tmp[8][8];
 134         uint8_t j;
 135         uint16_t i=hashsize_b;
 136         while(i>=64){
 137                 i-=64;
 138                 memcpy(tmp,ctx->s, 64);
 139                 twister_blank_round(ctx);
 140                 memxor(ctx->s, tmp, 64);
 141                 twister_blank_round(ctx);
 142                 for(j=0; j<8; ++j){
 143                         *((uint8_t*)dest) = ctx->s[7-j][0] ^ tmp[7-j][0];
 144                         dest = (uint8_t*)dest + 1;
 145                 }
 146         }
 147         if(i>=32){
 148                 memcpy(tmp,ctx->s, 64);
 149                 twister_blank_round(ctx);
 150                 memxor(ctx->s, tmp, 64);
 151                 twister_blank_round(ctx);
 152                 for(j=0; j<4; ++j){
 153                         *((uint8_t*)dest) = ctx->s[3-j][0] ^ tmp[3-j][0];
 154                         dest = (uint8_t*)dest + 1;
 155                 }
 156         }
 157 }
 158
 159 #endif