summaryrefslogtreecommitdiff
path: root/usr.bin/ssh/rijndael.c
blob: 98ecb55c811762a7105a251b41071d58ae32d576 (plain)
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
89
90
91
92
93
94
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
148
149
150
151
152
153
154
155
156
157
158
159
160
161
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
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
/*	$OpenBSD: rijndael.c,v 1.7 2001/02/04 15:32:24 stevesk Exp $	*/

/* This is an independent implementation of the encryption algorithm:   */
/*                                                                      */
/*         RIJNDAEL by Joan Daemen and Vincent Rijmen                   */
/*                                                                      */
/* which is a candidate algorithm in the Advanced Encryption Standard   */
/* programme of the US National Institute of Standards and Technology.  */
/*                                                                      */
/* Copyright in this implementation is held by Dr B R Gladman but I     */
/* hereby give permission for its free direct or derivative use subject */
/* to acknowledgment of its origin and compliance with any conditions   */
/* that the originators of the algorithm place on its exploitation.     */
/*                                                                      */
/* Dr Brian Gladman (gladman@seven77.demon.co.uk) 14th January 1999     */

/* Timing data for Rijndael (rijndael.c)

Algorithm: rijndael (rijndael.c)

128 bit key:
Key Setup:    305/1389 cycles (encrypt/decrypt)
Encrypt:       374 cycles =    68.4 mbits/sec
Decrypt:       352 cycles =    72.7 mbits/sec
Mean:          363 cycles =    70.5 mbits/sec

192 bit key:
Key Setup:    277/1595 cycles (encrypt/decrypt)
Encrypt:       439 cycles =    58.3 mbits/sec
Decrypt:       425 cycles =    60.2 mbits/sec
Mean:          432 cycles =    59.3 mbits/sec

256 bit key:
Key Setup:    374/1960 cycles (encrypt/decrypt)
Encrypt:       502 cycles =    51.0 mbits/sec
Decrypt:       498 cycles =    51.4 mbits/sec
Mean:          500 cycles =    51.2 mbits/sec

*/

#include <sys/types.h>
#include "rijndael.h"

void gen_tabs	__P((void));

/* 3. Basic macros for speeding up generic operations               */

/* Circular rotate of 32 bit values                                 */

#define rotr(x,n)   (((x) >> ((int)(n))) | ((x) << (32 - (int)(n))))
#define rotl(x,n)   (((x) << ((int)(n))) | ((x) >> (32 - (int)(n))))

/* Invert byte order in a 32 bit variable                           */

#define bswap(x)    ((rotl(x, 8) & 0x00ff00ff) | (rotr(x, 8) & 0xff00ff00))

/* Extract byte from a 32 bit quantity (little endian notation)     */

#define byte(x,n)   ((u1byte)((x) >> (8 * n)))

#if BYTE_ORDER != LITTLE_ENDIAN
#define BYTE_SWAP
#endif

#ifdef  BYTE_SWAP
#define io_swap(x)  bswap(x)
#else
#define io_swap(x)  (x)
#endif

#define LARGE_TABLES

u1byte  pow_tab[256];
u1byte  log_tab[256];
u1byte  sbx_tab[256];
u1byte  isb_tab[256];
u4byte  rco_tab[ 10];
u4byte  ft_tab[4][256];
u4byte  it_tab[4][256];

#ifdef  LARGE_TABLES
  u4byte  fl_tab[4][256];
  u4byte  il_tab[4][256];
#endif

u4byte  tab_gen = 0;

#define ff_mult(a,b)    (a && b ? pow_tab[(log_tab[a] + log_tab[b]) % 255] : 0)

#define f_rn(bo, bi, n, k)                          \
    bo[n] =  ft_tab[0][byte(bi[n],0)] ^             \
	     ft_tab[1][byte(bi[(n + 1) & 3],1)] ^   \
	     ft_tab[2][byte(bi[(n + 2) & 3],2)] ^   \
	     ft_tab[3][byte(bi[(n + 3) & 3],3)] ^ *(k + n)

#define i_rn(bo, bi, n, k)                          \
    bo[n] =  it_tab[0][byte(bi[n],0)] ^             \
	     it_tab[1][byte(bi[(n + 3) & 3],1)] ^   \
	     it_tab[2][byte(bi[(n + 2) & 3],2)] ^   \
	     it_tab[3][byte(bi[(n + 1) & 3],3)] ^ *(k + n)

#ifdef LARGE_TABLES

#define ls_box(x)                \
    ( fl_tab[0][byte(x, 0)] ^    \
      fl_tab[1][byte(x, 1)] ^    \
      fl_tab[2][byte(x, 2)] ^    \
      fl_tab[3][byte(x, 3)] )

#define f_rl(bo, bi, n, k)                          \
    bo[n] =  fl_tab[0][byte(bi[n],0)] ^             \
	     fl_tab[1][byte(bi[(n + 1) & 3],1)] ^   \
	     fl_tab[2][byte(bi[(n + 2) & 3],2)] ^   \
	     fl_tab[3][byte(bi[(n + 3) & 3],3)] ^ *(k + n)

#define i_rl(bo, bi, n, k)                          \
    bo[n] =  il_tab[0][byte(bi[n],0)] ^             \
	     il_tab[1][byte(bi[(n + 3) & 3],1)] ^   \
	     il_tab[2][byte(bi[(n + 2) & 3],2)] ^   \
	     il_tab[3][byte(bi[(n + 1) & 3],3)] ^ *(k + n)

#else

#define ls_box(x)                            \
    ((u4byte)sbx_tab[byte(x, 0)] <<  0) ^    \
    ((u4byte)sbx_tab[byte(x, 1)] <<  8) ^    \
    ((u4byte)sbx_tab[byte(x, 2)] << 16) ^    \
    ((u4byte)sbx_tab[byte(x, 3)] << 24)

#define f_rl(bo, bi, n, k)                                      \
    bo[n] = (u4byte)sbx_tab[byte(bi[n],0)] ^                    \
	rotl(((u4byte)sbx_tab[byte(bi[(n + 1) & 3],1)]),  8) ^  \
	rotl(((u4byte)sbx_tab[byte(bi[(n + 2) & 3],2)]), 16) ^  \
	rotl(((u4byte)sbx_tab[byte(bi[(n + 3) & 3],3)]), 24) ^ *(k + n)

#define i_rl(bo, bi, n, k)                                      \
    bo[n] = (u4byte)isb_tab[byte(bi[n],0)] ^                    \
	rotl(((u4byte)isb_tab[byte(bi[(n + 3) & 3],1)]),  8) ^  \
	rotl(((u4byte)isb_tab[byte(bi[(n + 2) & 3],2)]), 16) ^  \
	rotl(((u4byte)isb_tab[byte(bi[(n + 1) & 3],3)]), 24) ^ *(k + n)

#endif

void
gen_tabs(void)
{
	u4byte  i, t;
	u1byte  p, q;

	/* log and power tables for GF(2**8) finite field with  */
	/* 0x11b as modular polynomial - the simplest prmitive  */
	/* root is 0x11, used here to generate the tables       */

	for(i = 0,p = 1; i < 256; ++i) {
		pow_tab[i] = (u1byte)p; log_tab[p] = (u1byte)i;

		p = p ^ (p << 1) ^ (p & 0x80 ? 0x01b : 0);
	}

	log_tab[1] = 0; p = 1;

	for(i = 0; i < 10; ++i) {
		rco_tab[i] = p;

		p = (p << 1) ^ (p & 0x80 ? 0x1b : 0);
	}

	/* note that the affine byte transformation matrix in   */
	/* rijndael specification is in big endian format with  */
	/* bit 0 as the most significant bit. In the remainder  */
	/* of the specification the bits are numbered from the  */
	/* least significant end of a byte.                     */

	for(i = 0; i < 256; ++i) {
		p = (i ? pow_tab[255 - log_tab[i]] : 0); q = p;
		q = (q >> 7) | (q << 1); p ^= q;
		q = (q >> 7) | (q << 1); p ^= q;
		q = (q >> 7) | (q << 1); p ^= q;
		q = (q >> 7) | (q << 1); p ^= q ^ 0x63;
		sbx_tab[i] = (u1byte)p; isb_tab[p] = (u1byte)i;
	}

	for(i = 0; i < 256; ++i) {
		p = sbx_tab[i];

#ifdef  LARGE_TABLES

		t = p; fl_tab[0][i] = t;
		fl_tab[1][i] = rotl(t,  8);
		fl_tab[2][i] = rotl(t, 16);
		fl_tab[3][i] = rotl(t, 24);
#endif
		t = ((u4byte)ff_mult(2, p)) |
			((u4byte)p <<  8) |
			((u4byte)p << 16) |
			((u4byte)ff_mult(3, p) << 24);

		ft_tab[0][i] = t;
		ft_tab[1][i] = rotl(t,  8);
		ft_tab[2][i] = rotl(t, 16);
		ft_tab[3][i] = rotl(t, 24);

		p = isb_tab[i];

#ifdef  LARGE_TABLES

		t = p; il_tab[0][i] = t;
		il_tab[1][i] = rotl(t,  8);
		il_tab[2][i] = rotl(t, 16);
		il_tab[3][i] = rotl(t, 24);
#endif
		t = ((u4byte)ff_mult(14, p)) |
			((u4byte)ff_mult( 9, p) <<  8) |
			((u4byte)ff_mult(13, p) << 16) |
			((u4byte)ff_mult(11, p) << 24);

		it_tab[0][i] = t;
		it_tab[1][i] = rotl(t,  8);
		it_tab[2][i] = rotl(t, 16);
		it_tab[3][i] = rotl(t, 24);
	}

	tab_gen = 1;
}

#define star_x(x) (((x) & 0x7f7f7f7f) << 1) ^ ((((x) & 0x80808080) >> 7) * 0x1b)

#define imix_col(y,x)       \
    u   = star_x(x);        \
    v   = star_x(u);        \
    w   = star_x(v);        \
    t   = w ^ (x);          \
   (y)  = u ^ v ^ w;        \
   (y) ^= rotr(u ^ t,  8) ^ \
	  rotr(v ^ t, 16) ^ \
	  rotr(t,24)

/* initialise the key schedule from the user supplied key   */

#define loop4(i)                                    \
{   t = ls_box(rotr(t,  8)) ^ rco_tab[i];           \
    t ^= e_key[4 * i];     e_key[4 * i + 4] = t;    \
    t ^= e_key[4 * i + 1]; e_key[4 * i + 5] = t;    \
    t ^= e_key[4 * i + 2]; e_key[4 * i + 6] = t;    \
    t ^= e_key[4 * i + 3]; e_key[4 * i + 7] = t;    \
}

#define loop6(i)                                    \
{   t = ls_box(rotr(t,  8)) ^ rco_tab[i];           \
    t ^= e_key[6 * i];     e_key[6 * i + 6] = t;    \
    t ^= e_key[6 * i + 1]; e_key[6 * i + 7] = t;    \
    t ^= e_key[6 * i + 2]; e_key[6 * i + 8] = t;    \
    t ^= e_key[6 * i + 3]; e_key[6 * i + 9] = t;    \
    t ^= e_key[6 * i + 4]; e_key[6 * i + 10] = t;   \
    t ^= e_key[6 * i + 5]; e_key[6 * i + 11] = t;   \
}

#define loop8(i)                                    \
{   t = ls_box(rotr(t,  8)) ^ rco_tab[i];           \
    t ^= e_key[8 * i];     e_key[8 * i + 8] = t;    \
    t ^= e_key[8 * i + 1]; e_key[8 * i + 9] = t;    \
    t ^= e_key[8 * i + 2]; e_key[8 * i + 10] = t;   \
    t ^= e_key[8 * i + 3]; e_key[8 * i + 11] = t;   \
    t  = e_key[8 * i + 4] ^ ls_box(t);              \
    e_key[8 * i + 12] = t;                          \
    t ^= e_key[8 * i + 5]; e_key[8 * i + 13] = t;   \
    t ^= e_key[8 * i + 6]; e_key[8 * i + 14] = t;   \
    t ^= e_key[8 * i + 7]; e_key[8 * i + 15] = t;   \
}

rijndael_ctx *
rijndael_set_key(rijndael_ctx *ctx, const u4byte *in_key, const u4byte key_len,
		 int encrypt)
{
	u4byte  i, t, u, v, w;
	u4byte *e_key = ctx->e_key;
	u4byte *d_key = ctx->d_key;

	ctx->decrypt = !encrypt;

	if(!tab_gen)
		gen_tabs();

	ctx->k_len = (key_len + 31) / 32;

	e_key[0] = io_swap(in_key[0]); e_key[1] = io_swap(in_key[1]);
	e_key[2] = io_swap(in_key[2]); e_key[3] = io_swap(in_key[3]);

	switch(ctx->k_len) {
	case 4: t = e_key[3];
		for(i = 0; i < 10; ++i)
			loop4(i);
		break;

	case 6: e_key[4] = io_swap(in_key[4]); t = e_key[5] = io_swap(in_key[5]);
		for(i = 0; i < 8; ++i)
			loop6(i);
		break;

	case 8: e_key[4] = io_swap(in_key[4]); e_key[5] = io_swap(in_key[5]);
		e_key[6] = io_swap(in_key[6]); t = e_key[7] = io_swap(in_key[7]);
		for(i = 0; i < 7; ++i)
			loop8(i);
		break;
	}

	if (!encrypt) {
		d_key[0] = e_key[0]; d_key[1] = e_key[1];
		d_key[2] = e_key[2]; d_key[3] = e_key[3];

		for(i = 4; i < 4 * ctx->k_len + 24; ++i) {
			imix_col(d_key[i], e_key[i]);
		}
	}

	return ctx;
}

/* encrypt a block of text  */

#define f_nround(bo, bi, k) \
    f_rn(bo, bi, 0, k);     \
    f_rn(bo, bi, 1, k);     \
    f_rn(bo, bi, 2, k);     \
    f_rn(bo, bi, 3, k);     \
    k += 4

#define f_lround(bo, bi, k) \
    f_rl(bo, bi, 0, k);     \
    f_rl(bo, bi, 1, k);     \
    f_rl(bo, bi, 2, k);     \
    f_rl(bo, bi, 3, k)

void
rijndael_encrypt(rijndael_ctx *ctx, const u4byte *in_blk, u4byte *out_blk)
{
	u4byte k_len = ctx->k_len;
	u4byte *e_key = ctx->e_key;
	u4byte  b0[4], b1[4], *kp;

	b0[0] = io_swap(in_blk[0]) ^ e_key[0];
	b0[1] = io_swap(in_blk[1]) ^ e_key[1];
	b0[2] = io_swap(in_blk[2]) ^ e_key[2];
	b0[3] = io_swap(in_blk[3]) ^ e_key[3];

	kp = e_key + 4;

	if(k_len > 6) {
		f_nround(b1, b0, kp); f_nround(b0, b1, kp);
	}

	if(k_len > 4) {
		f_nround(b1, b0, kp); f_nround(b0, b1, kp);
	}

	f_nround(b1, b0, kp); f_nround(b0, b1, kp);
	f_nround(b1, b0, kp); f_nround(b0, b1, kp);
	f_nround(b1, b0, kp); f_nround(b0, b1, kp);
	f_nround(b1, b0, kp); f_nround(b0, b1, kp);
	f_nround(b1, b0, kp); f_lround(b0, b1, kp);

	out_blk[0] = io_swap(b0[0]); out_blk[1] = io_swap(b0[1]);
	out_blk[2] = io_swap(b0[2]); out_blk[3] = io_swap(b0[3]);
}

/* decrypt a block of text  */

#define i_nround(bo, bi, k) \
    i_rn(bo, bi, 0, k);     \
    i_rn(bo, bi, 1, k);     \
    i_rn(bo, bi, 2, k);     \
    i_rn(bo, bi, 3, k);     \
    k -= 4

#define i_lround(bo, bi, k) \
    i_rl(bo, bi, 0, k);     \
    i_rl(bo, bi, 1, k);     \
    i_rl(bo, bi, 2, k);     \
    i_rl(bo, bi, 3, k)

void
rijndael_decrypt(rijndael_ctx *ctx, const u4byte *in_blk, u4byte *out_blk)
{
	u4byte  b0[4], b1[4], *kp;
	u4byte k_len = ctx->k_len;
	u4byte *e_key = ctx->e_key;
	u4byte *d_key = ctx->d_key;

	b0[0] = io_swap(in_blk[0]) ^ e_key[4 * k_len + 24];
	b0[1] = io_swap(in_blk[1]) ^ e_key[4 * k_len + 25];
	b0[2] = io_swap(in_blk[2]) ^ e_key[4 * k_len + 26];
	b0[3] = io_swap(in_blk[3]) ^ e_key[4 * k_len + 27];

	kp = d_key + 4 * (k_len + 5);

	if(k_len > 6) {
		i_nround(b1, b0, kp); i_nround(b0, b1, kp);
	}

	if(k_len > 4) {
		i_nround(b1, b0, kp); i_nround(b0, b1, kp);
	}

	i_nround(b1, b0, kp); i_nround(b0, b1, kp);
	i_nround(b1, b0, kp); i_nround(b0, b1, kp);
	i_nround(b1, b0, kp); i_nround(b0, b1, kp);
	i_nround(b1, b0, kp); i_nround(b0, b1, kp);
	i_nround(b1, b0, kp); i_lround(b0, b1, kp);

	out_blk[0] = io_swap(b0[0]); out_blk[1] = io_swap(b0[1]);
	out_blk[2] = io_swap(b0[2]); out_blk[3] = io_swap(b0[3]);
}