xref: /freebsd/contrib/bearssl/src/symcipher/aes_ct64.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*
2  * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining
5  * a copy of this software and associated documentation files (the
6  * "Software"), to deal in the Software without restriction, including
7  * without limitation the rights to use, copy, modify, merge, publish,
8  * distribute, sublicense, and/or sell copies of the Software, and to
9  * permit persons to whom the Software is furnished to do so, subject to
10  * the following conditions:
11  *
12  * The above copyright notice and this permission notice shall be
13  * included in all copies or substantial portions of the Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22  * SOFTWARE.
23  */
24 
25 #include "inner.h"
26 
27 /* see inner.h */
28 void
29 br_aes_ct64_bitslice_Sbox(uint64_t *q)
30 {
31 	/*
32 	 * This S-box implementation is a straightforward translation of
33 	 * the circuit described by Boyar and Peralta in "A new
34 	 * combinational logic minimization technique with applications
35 	 * to cryptology" (https://eprint.iacr.org/2009/191.pdf).
36 	 *
37 	 * Note that variables x* (input) and s* (output) are numbered
38 	 * in "reverse" order (x0 is the high bit, x7 is the low bit).
39 	 */
40 
41 	uint64_t x0, x1, x2, x3, x4, x5, x6, x7;
42 	uint64_t y1, y2, y3, y4, y5, y6, y7, y8, y9;
43 	uint64_t y10, y11, y12, y13, y14, y15, y16, y17, y18, y19;
44 	uint64_t y20, y21;
45 	uint64_t z0, z1, z2, z3, z4, z5, z6, z7, z8, z9;
46 	uint64_t z10, z11, z12, z13, z14, z15, z16, z17;
47 	uint64_t t0, t1, t2, t3, t4, t5, t6, t7, t8, t9;
48 	uint64_t t10, t11, t12, t13, t14, t15, t16, t17, t18, t19;
49 	uint64_t t20, t21, t22, t23, t24, t25, t26, t27, t28, t29;
50 	uint64_t t30, t31, t32, t33, t34, t35, t36, t37, t38, t39;
51 	uint64_t t40, t41, t42, t43, t44, t45, t46, t47, t48, t49;
52 	uint64_t t50, t51, t52, t53, t54, t55, t56, t57, t58, t59;
53 	uint64_t t60, t61, t62, t63, t64, t65, t66, t67;
54 	uint64_t s0, s1, s2, s3, s4, s5, s6, s7;
55 
56 	x0 = q[7];
57 	x1 = q[6];
58 	x2 = q[5];
59 	x3 = q[4];
60 	x4 = q[3];
61 	x5 = q[2];
62 	x6 = q[1];
63 	x7 = q[0];
64 
65 	/*
66 	 * Top linear transformation.
67 	 */
68 	y14 = x3 ^ x5;
69 	y13 = x0 ^ x6;
70 	y9 = x0 ^ x3;
71 	y8 = x0 ^ x5;
72 	t0 = x1 ^ x2;
73 	y1 = t0 ^ x7;
74 	y4 = y1 ^ x3;
75 	y12 = y13 ^ y14;
76 	y2 = y1 ^ x0;
77 	y5 = y1 ^ x6;
78 	y3 = y5 ^ y8;
79 	t1 = x4 ^ y12;
80 	y15 = t1 ^ x5;
81 	y20 = t1 ^ x1;
82 	y6 = y15 ^ x7;
83 	y10 = y15 ^ t0;
84 	y11 = y20 ^ y9;
85 	y7 = x7 ^ y11;
86 	y17 = y10 ^ y11;
87 	y19 = y10 ^ y8;
88 	y16 = t0 ^ y11;
89 	y21 = y13 ^ y16;
90 	y18 = x0 ^ y16;
91 
92 	/*
93 	 * Non-linear section.
94 	 */
95 	t2 = y12 & y15;
96 	t3 = y3 & y6;
97 	t4 = t3 ^ t2;
98 	t5 = y4 & x7;
99 	t6 = t5 ^ t2;
100 	t7 = y13 & y16;
101 	t8 = y5 & y1;
102 	t9 = t8 ^ t7;
103 	t10 = y2 & y7;
104 	t11 = t10 ^ t7;
105 	t12 = y9 & y11;
106 	t13 = y14 & y17;
107 	t14 = t13 ^ t12;
108 	t15 = y8 & y10;
109 	t16 = t15 ^ t12;
110 	t17 = t4 ^ t14;
111 	t18 = t6 ^ t16;
112 	t19 = t9 ^ t14;
113 	t20 = t11 ^ t16;
114 	t21 = t17 ^ y20;
115 	t22 = t18 ^ y19;
116 	t23 = t19 ^ y21;
117 	t24 = t20 ^ y18;
118 
119 	t25 = t21 ^ t22;
120 	t26 = t21 & t23;
121 	t27 = t24 ^ t26;
122 	t28 = t25 & t27;
123 	t29 = t28 ^ t22;
124 	t30 = t23 ^ t24;
125 	t31 = t22 ^ t26;
126 	t32 = t31 & t30;
127 	t33 = t32 ^ t24;
128 	t34 = t23 ^ t33;
129 	t35 = t27 ^ t33;
130 	t36 = t24 & t35;
131 	t37 = t36 ^ t34;
132 	t38 = t27 ^ t36;
133 	t39 = t29 & t38;
134 	t40 = t25 ^ t39;
135 
136 	t41 = t40 ^ t37;
137 	t42 = t29 ^ t33;
138 	t43 = t29 ^ t40;
139 	t44 = t33 ^ t37;
140 	t45 = t42 ^ t41;
141 	z0 = t44 & y15;
142 	z1 = t37 & y6;
143 	z2 = t33 & x7;
144 	z3 = t43 & y16;
145 	z4 = t40 & y1;
146 	z5 = t29 & y7;
147 	z6 = t42 & y11;
148 	z7 = t45 & y17;
149 	z8 = t41 & y10;
150 	z9 = t44 & y12;
151 	z10 = t37 & y3;
152 	z11 = t33 & y4;
153 	z12 = t43 & y13;
154 	z13 = t40 & y5;
155 	z14 = t29 & y2;
156 	z15 = t42 & y9;
157 	z16 = t45 & y14;
158 	z17 = t41 & y8;
159 
160 	/*
161 	 * Bottom linear transformation.
162 	 */
163 	t46 = z15 ^ z16;
164 	t47 = z10 ^ z11;
165 	t48 = z5 ^ z13;
166 	t49 = z9 ^ z10;
167 	t50 = z2 ^ z12;
168 	t51 = z2 ^ z5;
169 	t52 = z7 ^ z8;
170 	t53 = z0 ^ z3;
171 	t54 = z6 ^ z7;
172 	t55 = z16 ^ z17;
173 	t56 = z12 ^ t48;
174 	t57 = t50 ^ t53;
175 	t58 = z4 ^ t46;
176 	t59 = z3 ^ t54;
177 	t60 = t46 ^ t57;
178 	t61 = z14 ^ t57;
179 	t62 = t52 ^ t58;
180 	t63 = t49 ^ t58;
181 	t64 = z4 ^ t59;
182 	t65 = t61 ^ t62;
183 	t66 = z1 ^ t63;
184 	s0 = t59 ^ t63;
185 	s6 = t56 ^ ~t62;
186 	s7 = t48 ^ ~t60;
187 	t67 = t64 ^ t65;
188 	s3 = t53 ^ t66;
189 	s4 = t51 ^ t66;
190 	s5 = t47 ^ t65;
191 	s1 = t64 ^ ~s3;
192 	s2 = t55 ^ ~t67;
193 
194 	q[7] = s0;
195 	q[6] = s1;
196 	q[5] = s2;
197 	q[4] = s3;
198 	q[3] = s4;
199 	q[2] = s5;
200 	q[1] = s6;
201 	q[0] = s7;
202 }
203 
204 /* see inner.h */
205 void
206 br_aes_ct64_ortho(uint64_t *q)
207 {
208 #define SWAPN(cl, ch, s, x, y)   do { \
209 		uint64_t a, b; \
210 		a = (x); \
211 		b = (y); \
212 		(x) = (a & (uint64_t)cl) | ((b & (uint64_t)cl) << (s)); \
213 		(y) = ((a & (uint64_t)ch) >> (s)) | (b & (uint64_t)ch); \
214 	} while (0)
215 
216 #define SWAP2(x, y)    SWAPN(0x5555555555555555, 0xAAAAAAAAAAAAAAAA,  1, x, y)
217 #define SWAP4(x, y)    SWAPN(0x3333333333333333, 0xCCCCCCCCCCCCCCCC,  2, x, y)
218 #define SWAP8(x, y)    SWAPN(0x0F0F0F0F0F0F0F0F, 0xF0F0F0F0F0F0F0F0,  4, x, y)
219 
220 	SWAP2(q[0], q[1]);
221 	SWAP2(q[2], q[3]);
222 	SWAP2(q[4], q[5]);
223 	SWAP2(q[6], q[7]);
224 
225 	SWAP4(q[0], q[2]);
226 	SWAP4(q[1], q[3]);
227 	SWAP4(q[4], q[6]);
228 	SWAP4(q[5], q[7]);
229 
230 	SWAP8(q[0], q[4]);
231 	SWAP8(q[1], q[5]);
232 	SWAP8(q[2], q[6]);
233 	SWAP8(q[3], q[7]);
234 }
235 
236 /* see inner.h */
237 void
238 br_aes_ct64_interleave_in(uint64_t *q0, uint64_t *q1, const uint32_t *w)
239 {
240 	uint64_t x0, x1, x2, x3;
241 
242 	x0 = w[0];
243 	x1 = w[1];
244 	x2 = w[2];
245 	x3 = w[3];
246 	x0 |= (x0 << 16);
247 	x1 |= (x1 << 16);
248 	x2 |= (x2 << 16);
249 	x3 |= (x3 << 16);
250 	x0 &= (uint64_t)0x0000FFFF0000FFFF;
251 	x1 &= (uint64_t)0x0000FFFF0000FFFF;
252 	x2 &= (uint64_t)0x0000FFFF0000FFFF;
253 	x3 &= (uint64_t)0x0000FFFF0000FFFF;
254 	x0 |= (x0 << 8);
255 	x1 |= (x1 << 8);
256 	x2 |= (x2 << 8);
257 	x3 |= (x3 << 8);
258 	x0 &= (uint64_t)0x00FF00FF00FF00FF;
259 	x1 &= (uint64_t)0x00FF00FF00FF00FF;
260 	x2 &= (uint64_t)0x00FF00FF00FF00FF;
261 	x3 &= (uint64_t)0x00FF00FF00FF00FF;
262 	*q0 = x0 | (x2 << 8);
263 	*q1 = x1 | (x3 << 8);
264 }
265 
266 /* see inner.h */
267 void
268 br_aes_ct64_interleave_out(uint32_t *w, uint64_t q0, uint64_t q1)
269 {
270 	uint64_t x0, x1, x2, x3;
271 
272 	x0 = q0 & (uint64_t)0x00FF00FF00FF00FF;
273 	x1 = q1 & (uint64_t)0x00FF00FF00FF00FF;
274 	x2 = (q0 >> 8) & (uint64_t)0x00FF00FF00FF00FF;
275 	x3 = (q1 >> 8) & (uint64_t)0x00FF00FF00FF00FF;
276 	x0 |= (x0 >> 8);
277 	x1 |= (x1 >> 8);
278 	x2 |= (x2 >> 8);
279 	x3 |= (x3 >> 8);
280 	x0 &= (uint64_t)0x0000FFFF0000FFFF;
281 	x1 &= (uint64_t)0x0000FFFF0000FFFF;
282 	x2 &= (uint64_t)0x0000FFFF0000FFFF;
283 	x3 &= (uint64_t)0x0000FFFF0000FFFF;
284 	w[0] = (uint32_t)x0 | (uint32_t)(x0 >> 16);
285 	w[1] = (uint32_t)x1 | (uint32_t)(x1 >> 16);
286 	w[2] = (uint32_t)x2 | (uint32_t)(x2 >> 16);
287 	w[3] = (uint32_t)x3 | (uint32_t)(x3 >> 16);
288 }
289 
290 static const unsigned char Rcon[] = {
291 	0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1B, 0x36
292 };
293 
294 static uint32_t
295 sub_word(uint32_t x)
296 {
297 	uint64_t q[8];
298 
299 	memset(q, 0, sizeof q);
300 	q[0] = x;
301 	br_aes_ct64_ortho(q);
302 	br_aes_ct64_bitslice_Sbox(q);
303 	br_aes_ct64_ortho(q);
304 	return (uint32_t)q[0];
305 }
306 
307 /* see inner.h */
308 unsigned
309 br_aes_ct64_keysched(uint64_t *comp_skey, const void *key, size_t key_len)
310 {
311 	unsigned num_rounds;
312 	int i, j, k, nk, nkf;
313 	uint32_t tmp;
314 	uint32_t skey[60];
315 
316 	switch (key_len) {
317 	case 16:
318 		num_rounds = 10;
319 		break;
320 	case 24:
321 		num_rounds = 12;
322 		break;
323 	case 32:
324 		num_rounds = 14;
325 		break;
326 	default:
327 		/* abort(); */
328 		return 0;
329 	}
330 	nk = (int)(key_len >> 2);
331 	nkf = (int)((num_rounds + 1) << 2);
332 	br_range_dec32le(skey, (key_len >> 2), key);
333 	tmp = skey[(key_len >> 2) - 1];
334 	for (i = nk, j = 0, k = 0; i < nkf; i ++) {
335 		if (j == 0) {
336 			tmp = (tmp << 24) | (tmp >> 8);
337 			tmp = sub_word(tmp) ^ Rcon[k];
338 		} else if (nk > 6 && j == 4) {
339 			tmp = sub_word(tmp);
340 		}
341 		tmp ^= skey[i - nk];
342 		skey[i] = tmp;
343 		if (++ j == nk) {
344 			j = 0;
345 			k ++;
346 		}
347 	}
348 
349 	for (i = 0, j = 0; i < nkf; i += 4, j += 2) {
350 		uint64_t q[8];
351 
352 		br_aes_ct64_interleave_in(&q[0], &q[4], skey + i);
353 		q[1] = q[0];
354 		q[2] = q[0];
355 		q[3] = q[0];
356 		q[5] = q[4];
357 		q[6] = q[4];
358 		q[7] = q[4];
359 		br_aes_ct64_ortho(q);
360 		comp_skey[j + 0] =
361 			  (q[0] & (uint64_t)0x1111111111111111)
362 			| (q[1] & (uint64_t)0x2222222222222222)
363 			| (q[2] & (uint64_t)0x4444444444444444)
364 			| (q[3] & (uint64_t)0x8888888888888888);
365 		comp_skey[j + 1] =
366 			  (q[4] & (uint64_t)0x1111111111111111)
367 			| (q[5] & (uint64_t)0x2222222222222222)
368 			| (q[6] & (uint64_t)0x4444444444444444)
369 			| (q[7] & (uint64_t)0x8888888888888888);
370 	}
371 	return num_rounds;
372 }
373 
374 /* see inner.h */
375 void
376 br_aes_ct64_skey_expand(uint64_t *skey,
377 	unsigned num_rounds, const uint64_t *comp_skey)
378 {
379 	unsigned u, v, n;
380 
381 	n = (num_rounds + 1) << 1;
382 	for (u = 0, v = 0; u < n; u ++, v += 4) {
383 		uint64_t x0, x1, x2, x3;
384 
385 		x0 = x1 = x2 = x3 = comp_skey[u];
386 		x0 &= (uint64_t)0x1111111111111111;
387 		x1 &= (uint64_t)0x2222222222222222;
388 		x2 &= (uint64_t)0x4444444444444444;
389 		x3 &= (uint64_t)0x8888888888888888;
390 		x1 >>= 1;
391 		x2 >>= 2;
392 		x3 >>= 3;
393 		skey[v + 0] = (x0 << 4) - x0;
394 		skey[v + 1] = (x1 << 4) - x1;
395 		skey[v + 2] = (x2 << 4) - x2;
396 		skey[v + 3] = (x3 << 4) - x3;
397 	}
398 }
399