camellia-set-encrypt-key.c 8.44 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80
/* camellia-set-encrypt-key.c
 *
 * Key setup for the camellia block cipher.
 */
/*
 * Copyright (C) 2006,2007
 * NTT (Nippon Telegraph and Telephone Corporation).
 *
 * Copyright (C) 2010 Niels Mller
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 */

/*
 * Algorithm Specification 
 *  http://info.isl.ntt.co.jp/crypt/eng/camellia/specifications.html
 */

/* Based on camellia.c ver 1.2.0, see
   http://info.isl.ntt.co.jp/crypt/eng/camellia/dl/camellia-LGPL-1.2.0.tar.gz.
 */
#if HAVE_CONFIG_H
# include "config.h"
#endif

#include <assert.h>

#include "camellia-internal.h"

#include "macros.h"

/* key constants */

#define SIGMA1 0xA09E667F3BCC908BULL
#define SIGMA2 0xB67AE8584CAA73B2ULL
#define SIGMA3 0xC6EF372FE94F82BEULL
#define SIGMA4 0x54FF53A5F1D36F1CULL
#define SIGMA5 0x10E527FADE682D1DULL
#define SIGMA6 0xB05688C2B3E6C1FDULL

#define CAMELLIA_SP1110(INDEX) (_nettle_camellia_table.sp1110[(int)(INDEX)])
#define CAMELLIA_SP0222(INDEX) (_nettle_camellia_table.sp0222[(int)(INDEX)])
#define CAMELLIA_SP3033(INDEX) (_nettle_camellia_table.sp3033[(int)(INDEX)])
#define CAMELLIA_SP4404(INDEX) (_nettle_camellia_table.sp4404[(int)(INDEX)])

#define CAMELLIA_F(x, k, y) do {		\
    uint32_t __yl, __yr;			\
    uint64_t __i = (x) ^ (k);			\
    __yl					\
      = CAMELLIA_SP1110( __i & 0xff)		\
      ^ CAMELLIA_SP0222((__i >> 24) & 0xff)	\
      ^ CAMELLIA_SP3033((__i >> 16) & 0xff)	\
      ^ CAMELLIA_SP4404((__i >> 8) & 0xff);	\
    __yr					\
      = CAMELLIA_SP1110( __i >> 56)		\
      ^ CAMELLIA_SP0222((__i >> 48) & 0xff)	\
      ^ CAMELLIA_SP3033((__i >> 40) & 0xff)	\
      ^ CAMELLIA_SP4404((__i >> 32) & 0xff);	\
    __yl ^= __yr;				\
    __yr = ROL32(24, __yr);			\
    __yr ^= __yl;				\
    (y) = ((uint64_t) __yl << 32) | __yr;	\
  } while (0)

void
camellia_set_encrypt_key(struct camellia_ctx *ctx,
			 unsigned length, const uint8_t *key)
{
81
  uint64_t k0, k1;
82 83

  uint64_t subkey[34];
84
  uint64_t w, kw2, kw4;
85 86 87 88
  
  uint32_t dw, tl, tr;
  unsigned i;

89 90
  k0 = READ_UINT64(key);
  k1 = READ_UINT64(key +  8);
91 92 93
  
  if (length == 16)
    {
94
      ctx->nkeys = 24;
95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147
      /**
       * generate KL dependent subkeys
       */
      subkey[0] = k0; subkey[1] = k1;
      ROL128(15, k0, k1);
      subkey[4] = k0; subkey[5] = k1;
      ROL128(30, k0, k1);
      subkey[10] = k0; subkey[11] = k1;
      ROL128(15, k0, k1);
      subkey[13] = k1;
      ROL128(17, k0, k1);
      subkey[16] = k0; subkey[17] = k1;
      ROL128(17, k0, k1);
      subkey[18] = k0; subkey[19] = k1;
      ROL128(17, k0, k1);
      subkey[22] = k0; subkey[23] = k1;

      /* generate KA. D1 is k0, d2 is k1. */
      /* FIXME: Make notation match the spec better. */
      /* For the 128-bit case, KR = 0, the construction of KA reduces to:

	 D1 = KL >> 64;
	 W = KL & MASK64;
	 D2 = F(D1, Sigma1);
	 W = D2 ^ W
	 D1 = F(W, Sigma2)
	 D2 = D2 ^ F(D1, Sigma3);
	 D1 = D1 ^ F(D2, Sigma4);
	 KA = (D1 << 64) | D2;
      */
      k0 = subkey[0]; w = subkey[1];
      CAMELLIA_F(k0, SIGMA1, k1);
      w ^= k1;
      CAMELLIA_F(w, SIGMA2, k0);
      CAMELLIA_F(k0, SIGMA3, w);
      k1 ^= w;
      CAMELLIA_F(k1, SIGMA4, w);
      k0 ^= w;

      /* generate KA dependent subkeys */
      subkey[2] = k0; subkey[3] = k1;
      ROL128(15, k0, k1);
      subkey[6] = k0; subkey[7] = k1;
      ROL128(15, k0, k1);
      subkey[8] = k0; subkey[9] = k1;
      ROL128(15, k0, k1);
      subkey[12] = k0;
      ROL128(15, k0, k1);
      subkey[14] = k0; subkey[15] = k1;
      ROL128(34, k0, k1);
      subkey[20] = k0; subkey[21] = k1;
      ROL128(17, k0, k1);
      subkey[24] = k0; subkey[25] = k1;
148 149 150
    }
  else
    {
151
      uint64_t k2, k3;
152 153

      ctx->nkeys = 32;
154
      k2 = READ_UINT64(key + 16);
155 156

      if (length == 24)
157
	k3 = ~k2;
158 159 160
      else
	{
	  assert (length == 32);
161
	  k3 = READ_UINT64(key + 24);
162
	}
163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238
      /* generate KL dependent subkeys */
      subkey[0] = k0; subkey[1] = k1;
      ROL128(45, k0, k1);
      subkey[12] = k0; subkey[13] = k1;
      ROL128(15, k0, k1);
      subkey[16] = k0; subkey[17] = k1;
      ROL128(17, k0, k1);
      subkey[22] = k0; subkey[23] = k1;
      ROL128(34, k0, k1);
      subkey[30] = k0; subkey[31] = k1;

      /* generate KR dependent subkeys */
      ROL128(15, k2, k3);
      subkey[4] = k2; subkey[5] = k3;
      ROL128(15, k2, k3);
      subkey[8] = k2; subkey[9] = k3;
      ROL128(30, k2, k3);
      subkey[18] = k2; subkey[19] = k3;
      ROL128(34, k2, k3);
      subkey[26] = k2; subkey[27] = k3;
      ROL128(34, k2, k3);

      /* generate KA */
      /* The construction of KA is done as

	 D1 = (KL ^ KR) >> 64
	 D2 = (KL ^ KR) & MASK64
	 W = F(D1, SIGMA1)
	 D2 = D2 ^ W
	 D1 = F(D2, SIGMA2) ^ (KR >> 64)
	 D2 = F(D1, SIGMA3) ^ W ^ (KR & MASK64)
	 D1 = D1 ^ F(W, SIGMA2)
	 D2 = D2 ^ F(D1, SIGMA3)
	 D1 = D1 ^ F(D2, SIGMA4)
      */

      k0 = subkey[0] ^ k2;
      k1 = subkey[1] ^ k3;

      CAMELLIA_F(k0, SIGMA1, w);
      k1 ^= w;

      CAMELLIA_F(k1, SIGMA2, k0);
      k0 ^= k2;

      CAMELLIA_F(k0, SIGMA3, k1);
      k1 ^= w ^ k3;

      CAMELLIA_F(k1, SIGMA4, w);
      k0 ^= w;

      /* generate KB */
      k2 ^= k0; k3 ^= k1;
      CAMELLIA_F(k2, SIGMA5, w);
      k3 ^= w;
      CAMELLIA_F(k3, SIGMA6, w);
      k2 ^= w;

      /* generate KA dependent subkeys */
      ROL128(15, k0, k1);
      subkey[6] = k0; subkey[7] = k1;
      ROL128(30, k0, k1);
      subkey[14] = k0; subkey[15] = k1;
      ROL128(32, k0, k1);
      subkey[24] = k0; subkey[25] = k1;
      ROL128(17, k0, k1);
      subkey[28] = k0; subkey[29] = k1;

      /* generate KB dependent subkeys */
      subkey[2] = k2; subkey[3] = k3;
      ROL128(30, k2, k3);
      subkey[10] = k2; subkey[11] = k3;
      ROL128(30, k2, k3);
      subkey[20] = k2; subkey[21] = k3;
      ROL128(51, k2, k3);
      subkey[32] = k2; subkey[33] = k3;
239 240
    }

241 242 243
  /* At this point, the subkey array contains the subkeys as described
     in the spec, 26 for short keys and 34 for large keys. */

244
  /* absorb kw2 to other subkeys */
245
  kw2 = subkey[1];
246

247 248 249
  subkey[3] ^= kw2;
  subkey[5] ^= kw2;
  subkey[7] ^= kw2;
250
  for (i = 8; i < ctx->nkeys; i += 8)
251 252 253 254 255 256 257 258 259 260
    {
      /* FIXME: gcc for x86_32 is smart enough to fetch the 32 low bits
	 and xor the result into the 32 high bits, but it still generates
	 worse code than for explicit 32-bit operations. */
      kw2 ^= (kw2 & ~subkey[i+1]) << 32;
      dw = (kw2 & subkey[i+1]) >> 32; kw2 ^= ROL32(1, dw); 

      subkey[i+3] ^= kw2;
      subkey[i+5] ^= kw2;
      subkey[i+7] ^= kw2;
261
    }
262 263
  subkey[i] ^= kw2;
  
264
  /* absorb kw4 to other subkeys */  
265
  kw4 = subkey[ctx->nkeys + 1];
266

267
  for (i = ctx->nkeys - 8; i > 0; i -= 8)
268
    {
269 270 271 272 273
      subkey[i+6] ^= kw4;
      subkey[i+4] ^= kw4;
      subkey[i+2] ^= kw4;
      kw4 ^= (kw4 & ~subkey[i]) << 32;
      dw = (kw4 & subkey[i]) >> 32; kw4 ^= ROL32(1, dw);      
274 275 276 277 278 279 280 281
    }

  subkey[6] ^= kw4;
  subkey[4] ^= kw4;
  subkey[2] ^= kw4;
  subkey[0] ^= kw4;

  /* key XOR is end of F-function */
282
  ctx->keys[0] = subkey[0] ^ subkey[2];
283
  ctx->keys[1] = subkey[3];
284

285 286 287 288
  ctx->keys[2] = subkey[2] ^ subkey[4];
  ctx->keys[3] = subkey[3] ^ subkey[5];
  ctx->keys[4] = subkey[4] ^ subkey[6];
  ctx->keys[5] = subkey[5] ^ subkey[7];
289

290
  for (i = 8; i < ctx->nkeys; i += 8)
291
    {
292 293 294
      tl = (subkey[i+2] >> 32) ^ (subkey[i+2] & ~subkey[i]);
      dw = tl & (subkey[i] >> 32);
      tr = subkey[i+2] ^ ROL32(1, dw);
295
      ctx->keys[i-2] = subkey[i-2] ^ ( ((uint64_t) tl << 32) | tr);
296

297 298
      ctx->keys[i-1] = subkey[i];
      ctx->keys[i] = subkey[i+1];
299 300 301 302

      tl = (subkey[i-1] >> 32) ^ (subkey[i-1] & ~subkey[i+1]);
      dw = tl & (subkey[i+1] >> 32);
      tr = subkey[i-1] ^ ROL32(1, dw);
303
      ctx->keys[i+1] = subkey[i+3] ^ ( ((uint64_t) tl << 32) | tr);
304

305 306 307 308
      ctx->keys[i+2] = subkey[i+2] ^ subkey[i+4];
      ctx->keys[i+3] = subkey[i+3] ^ subkey[i+5];
      ctx->keys[i+4] = subkey[i+4] ^ subkey[i+6];
      ctx->keys[i+5] = subkey[i+5] ^ subkey[i+7];
309
    }
310 311
  ctx->keys[i-2] = subkey[i-2];
  ctx->keys[i-1] = subkey[i] ^ subkey[i-1];
312
}