camellia-set-encrypt-key.c 9.01 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
81
82
83
84
85
86
87
88
/* 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)

#define CAMELLIA_F_HALF_INV(x) do {		\
    uint32_t __t, __w;				\
    __t = (x) >> 32;				\
    __w = __t ^(x);				\
    __w = ROL32(8, __w);			\
    (x) = ((uint64_t) __w << 32) | (__t ^ __w);	\
  } while (0)

void
camellia_set_encrypt_key(struct camellia_ctx *ctx,
			 unsigned length, const uint8_t *key)
{
89
  uint64_t k0, k1;
90
91

  uint64_t subkey[34];
92
  uint64_t w, kw2, kw4;
93
94
95
96
  
  uint32_t dw, tl, tr;
  unsigned i;

97
98
  k0 = READ_UINT64(key);
  k1 = READ_UINT64(key +  8);
99
100
101
102
  
  if (length == 16)
    {
      ctx->nkeys = 26;
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
148
149
150
151
152
153
154
155
      /**
       * 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;
156
157
158
    }
  else
    {
159
      uint64_t k2, k3;
160
      ctx->nkeys = 34;
161
      k2 = READ_UINT64(key + 16);
162
163

      if (length == 24)
164
	k3 = ~k2;
165
166
167
      else
	{
	  assert (length == 32);
168
	  k3 = READ_UINT64(key + 24);
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
239
240
241
242
243
244
245
      /* 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;
246
247
    }

248
249
250
  /* At this point, the subkey array contains the subkeys as described
     in the spec, 26 for short keys and 34 for large keys. */

251
  /* absorb kw2 to other subkeys */
252
  kw2 = subkey[1];
253

254
255
256
257
258
259
260
261
262
263
264
265
266
267
  subkey[3] ^= kw2;
  subkey[5] ^= kw2;
  subkey[7] ^= kw2;
  for (i = 8; i < ctx->nkeys - 2; i += 8)
    {
      /* 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;
268
    }
269
270
  subkey[i] ^= kw2;
  
271
272
  /* absorb kw4 to other subkeys */  
  kw4 = subkey[ctx->nkeys - 1];
273
274

  for (i = ctx->nkeys - 10; i > 0; i -= 8)
275
    {
276
277
278
279
280
      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);      
281
282
283
284
285
286
287
288
    }

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

  /* key XOR is end of F-function */
289
  ctx->keys[0] = subkey[0] ^ subkey[2];
290
  ctx->keys[2] = subkey[3];
291

292
293
294
295
296
  ctx->keys[3] = subkey[2] ^ subkey[4];
  ctx->keys[4] = subkey[3] ^ subkey[5];
  ctx->keys[5] = subkey[4] ^ subkey[6];
  ctx->keys[6] = subkey[5] ^ subkey[7];

297
  for (i = 8; i < ctx->nkeys - 2; i += 8)
298
    {
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
      tl = (subkey[i+2] >> 32) ^ (subkey[i+2] & ~subkey[i]);
      dw = tl & (subkey[i] >> 32);
      tr = subkey[i+2] ^ ROL32(1, dw);
      ctx->keys[i-1] = subkey[i-2] ^ ( ((uint64_t) tl << 32) | tr);

      ctx->keys[i] = subkey[i];
      ctx->keys[i+1] = subkey[i+1];

      tl = (subkey[i-1] >> 32) ^ (subkey[i-1] & ~subkey[i+1]);
      dw = tl & (subkey[i+1] >> 32);
      tr = subkey[i-1] ^ ROL32(1, dw);
      ctx->keys[i+2] = subkey[i+3] ^ ( ((uint64_t) tl << 32) | tr);

      ctx->keys[i+3] = subkey[i+2] ^ subkey[i+4];
      ctx->keys[i+4] = subkey[i+3] ^ subkey[i+5];
      ctx->keys[i+5] = subkey[i+4] ^ subkey[i+6];
      ctx->keys[i+6] = subkey[i+5] ^ subkey[i+7];
316
    }
317
318
319
  ctx->keys[i-1] = subkey[i-2];
  ctx->keys[i] = subkey[i] ^ subkey[i-1];

320
321
322
323
324
325
326
327
328
329
330
  for (i = 0; i < ctx->nkeys - 2; i += 8)
    {
      /* apply the inverse of the last half of F-function */
      CAMELLIA_F_HALF_INV(ctx->keys[i+2]);
      CAMELLIA_F_HALF_INV(ctx->keys[i+3]);
      CAMELLIA_F_HALF_INV(ctx->keys[i+4]);
      CAMELLIA_F_HALF_INV(ctx->keys[i+5]);
      CAMELLIA_F_HALF_INV(ctx->keys[i+6]);
      CAMELLIA_F_HALF_INV(ctx->keys[i+7]);
    }
}