keccak/keccak.c

   1 /* keecak.c */
   2 /*
   3     This file is part of the AVR-Crypto-Lib.
   4     Copyright (C) 2010 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 <stdint.h>
  21 #include <stdlib.h>
  22 #include <string.h>
  23 #include <avr/pgmspace.h>
  24 #include "memxor.h"
  25 #include "keccak.h"
  26
  27 #ifdef DEBUG
  28 #  undef DEBUG
  29 #endif
  30
  31 #define DEBUG 0
  32
  33 #if DEBUG
  34 #include "cli.h"
  35
  36 void keccak_dump_state(uint64_t a[5][5]){
  37         uint8_t i,j;
  38         for(i=0; i<5; ++i){
  39                 cli_putstr_P(PSTR("\r\n"));
  40                 cli_putc('0'+i);
  41                 cli_putstr_P(PSTR(": "));
  42                 for(j=0; j<5; ++j){
  43                         cli_hexdump_rev(&(a[i][j]), 8);
  44                         cli_putc(' ');
  45                 }
  46         }
  47 }
  48
  49 void keccak_dump_ctx(keccak_ctx_t* ctx){
  50         keccak_dump_state(ctx->a);
  51         cli_putstr_P(PSTR("\r\nDBG: r: "));
  52         cli_hexdump_rev(&(ctx->r), 2);
  53         cli_putstr_P(PSTR("\t c: "));
  54         cli_hexdump_rev(&(ctx->c), 2);
  55         cli_putstr_P(PSTR("\t d: "));
  56         cli_hexdump(&(ctx->d), 1);
  57         cli_putstr_P(PSTR("\t bs: "));
  58         cli_hexdump(&(ctx->bs), 1);
  59 }
  60
  61 #endif
  62
  63 static uint64_t rc[] PROGMEM = {
  64        0x0000000000000001LL, 0x0000000000008082LL,
  65        0x800000000000808ALL, 0x8000000080008000LL,
  66        0x000000000000808BLL, 0x0000000080000001LL,
  67        0x8000000080008081LL, 0x8000000000008009LL,
  68        0x000000000000008ALL, 0x0000000000000088LL,
  69        0x0000000080008009LL, 0x000000008000000ALL,
  70        0x000000008000808BLL, 0x800000000000008BLL,
  71        0x8000000000008089LL, 0x8000000000008003LL,
  72        0x8000000000008002LL, 0x8000000000000080LL,
  73        0x000000000000800ALL, 0x800000008000000ALL,
  74        0x8000000080008081LL, 0x8000000000008080LL,
  75        0x0000000080000001LL, 0x8000000080008008LL
  76 };
  77
  78 uint64_t rotl64(uint64_t a, uint8_t r){
  79          return (a<<r)|(a>>(64-r));
  80 }
  81
  82 static uint8_t r[5][5] PROGMEM = {
  83                 {  0, 36,  3, 41, 18 },
  84                 {  1, 44, 10, 45,  2 },
  85                 { 62,  6, 43, 15, 61 },
  86                 { 28, 55, 25, 21, 56 },
  87                 { 27, 20, 39,  8, 14 }
  88 };
  89
  90 void keccak_round(uint64_t a[5][5], uint8_t rci){
  91         uint64_t b[5][5];
  92         uint8_t i,j;
  93         /* theta */
  94         for(i=0; i<5; ++i){
  95                 b[i][0] = a[0][i] ^ a[1][i] ^ a[2][i] ^ a[3][i] ^ a[4][i];
  96         }
  97         for(i=0; i<5; ++i){
  98                 b[i][1] = b[(4+i)%5][0] ^ rotl64(b[(i+1)%5][0], 1);
  99         }
 100         for(i=0; i<5; ++i){
 101                 for(j=0; j<5; ++j){
 102                         a[j][i] ^= b[i][1];
 103                 }
 104         }
 105 #if DEBUG
 106         cli_putstr_P(PSTR("\r\nAfter theta:"));
 107         keccak_dump_state(a);
 108 #endif
 109         /* rho & pi */
 110         for(i=0; i<5; ++i){
 111                 for(j=0; j<5; ++j){
 112                         b[(2*i+3*j)%5][j] = rotl64(a[j][i], pgm_read_byte(&(r[i][j])));
 113                 }
 114         }
 115 #if DEBUG
 116         cli_putstr_P(PSTR("\r\n--- after rho & pi ---"));
 117         keccak_dump_state(a);
 118 #endif
 119         /* chi */
 120         for(i=0; i<5; ++i){
 121                 for(j=0; j<5; ++j){
 122                         a[j][i] =  b[j][i] ^ ((~(b[j][(i+1)%5]))&(b[j][(i+2)%5]));
 123                 }
 124         }
 125 #if DEBUG
 126         cli_putstr_P(PSTR("\r\nAfter chi:"));
 127         keccak_dump_state(a);
 128 #endif
 129         /* iota */
 130         uint64_t t;
 131         memcpy_P(&t, &(rc[rci]), 8);
 132         a[0][0] ^= t;
 133 #if DEBUG
 134         cli_putstr_P(PSTR("\r\nAfter iota:"));
 135         keccak_dump_state(a);
 136 #endif
 137 }
 138
 139 void keccak_f1600(uint64_t a[5][5]){
 140         uint8_t i=0;
 141         do{
 142 #if DEBUG
 143                 cli_putstr_P(PSTR("\r\n\r\n--- Round "));
 144                 cli_hexdump(&i, 1);
 145                 cli_putstr_P(PSTR(" ---"));
 146 #endif
 147                 keccak_round(a, i);
 148         }while(++i<24);
 149 }
 150
 151 void keccak_nextBlock(keccak_ctx_t* ctx, const void* block){
 152         memxor(ctx->a, block, ctx->bs);
 153         keccak_f1600(ctx->a);
 154 }
 155
 156 void keccak_lastBlock(keccak_ctx_t* ctx, const void* block, uint16_t length_b){
 157         while(length_b>=ctx->r){
 158                 keccak_nextBlock(ctx, block);
 159                 block = (uint8_t*)block + ctx->bs;
 160                 length_b -=  ctx->r;
 161         }
 162         uint8_t tmp[ctx->bs];
 163         uint8_t pad[3];
 164         memset(tmp, 0x00, ctx->bs);
 165         memcpy(tmp, block, (length_b+7)/8);
 166         /* appand 1 */
 167         if(length_b&7){
 168                 /* we have some single bits */
 169                 uint8_t t;
 170                 t = tmp[length_b/8]>>(8-(length_b&7));
 171                 t |= 0x01<<(length_b&7);
 172                 tmp[length_b/8] = t;
 173         }else{
 174                 tmp[length_b/8] = 0x01;
 175         }
 176         pad[0] = ctx->d;
 177         pad[1] = ctx->bs;
 178         pad[2] = 0x01;
 179         if(length_b/8+1+3<=ctx->bs){
 180                 memcpy(tmp+length_b/8+1, pad, 3);
 181         }else{
 182                 if(length_b/8+1+2<=ctx->bs){
 183                         memcpy(tmp+length_b/8+1, pad, 2);
 184                         keccak_nextBlock(ctx, tmp);
 185                         memset(tmp, 0x00, ctx->bs);
 186                         tmp[0]=0x01;
 187                 }else{
 188                         if(length_b/8+1+1<=ctx->bs){
 189                                 memcpy(tmp+length_b/8+1, pad, 1);
 190                                 keccak_nextBlock(ctx, tmp);
 191                                 memset(tmp, 0x00, ctx->bs);
 192                                 tmp[0] = ctx->bs;
 193                                 tmp[1] = 0x01;
 194                         }else{
 195                                 keccak_nextBlock(ctx, tmp);
 196                                 memset(tmp, 0x00, ctx->bs);
 197                                 tmp[0] = ctx->d;
 198                                 tmp[1] = ctx->bs;
 199                                 tmp[2] = 0x01;
 200                         }
 201                 }
 202         }
 203         keccak_nextBlock(ctx, tmp);
 204 }
 205
 206 void keccak_ctx2hash(void* dest, uint16_t length_b, keccak_ctx_t* ctx){
 207         while(length_b>=ctx->r){
 208                 memcpy(dest, ctx->a, ctx->bs);
 209                 dest = (uint8_t*)dest + ctx->bs;
 210                 length_b -= ctx->r;
 211                 keccak_f1600(ctx->a);
 212         }
 213         memcpy(dest, ctx->a, (length_b+7)/8);
 214 }
 215
 216 void keccak224_ctx2hash(void* dest, keccak_ctx_t* ctx){
 217         keccak_ctx2hash(dest, 224, ctx);
 218 }
 219
 220 void keccak256_ctx2hash(void* dest, keccak_ctx_t* ctx){
 221         keccak_ctx2hash(dest, 256, ctx);
 222 }
 223
 224 void keccak384_ctx2hash(void* dest, keccak_ctx_t* ctx){
 225         keccak_ctx2hash(dest, 384, ctx);
 226 }
 227
 228 void keccak512_ctx2hash(void* dest, keccak_ctx_t* ctx){
 229         keccak_ctx2hash(dest, 512, ctx);
 230 }
 231
 232 /*
 233 1. SHA3-224: ⌊Keccak[r = 1152, c = 448, d = 28]⌋224
 234 2. SHA3-256: ⌊Keccak[r = 1088, c = 512, d = 32]⌋256
 235 3. SHA3-384: ⌊Keccak[r = 832, c = 768, d = 48]⌋384
 236 4. SHA3-512: ⌊Keccak[r = 576, c = 1024, d = 64]⌋512
 237 */
 238 void keccak_init(uint16_t r, uint16_t c, uint8_t d, keccak_ctx_t* ctx){
 239         memset(ctx->a, 0x00, 5*5*8);
 240         ctx->r = r;
 241         ctx->c = c;
 242         ctx->d = d;
 243         ctx->bs = (uint8_t)(r/8);
 244 }
 245
 246 void keccak224_init(keccak_ctx_t* ctx){
 247         keccak_init(1152, 448, 28, ctx);
 248 }
 249
 250 void keccak256_init(keccak_ctx_t* ctx){
 251         keccak_init(1088, 512, 32, ctx);
 252 }
 253
 254 void keccak384_init(keccak_ctx_t* ctx){
 255         keccak_init( 832, 768, 48, ctx);
 256 }
 257
 258 void keccak512_init(keccak_ctx_t* ctx){
 259         keccak_init( 576, 1024, 64, ctx);
 260 }