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 */
28void
29br_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 */
205void
206br_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 */
237void
238br_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 */
267void
268br_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
290static const unsigned char Rcon[] = {
291	0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1B, 0x36
292};
293
294static uint32_t
295sub_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 */
308unsigned
309br_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 */
375void
376br_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