1/* $NetBSD: aes_ct64.c,v 1.1 2025/11/23 22:44:13 riastradh Exp $ */ 2 3/* 4 * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org> 5 * 6 * Permission is hereby granted, free of charge, to any person obtaining 7 * a copy of this software and associated documentation files (the 8 * "Software"), to deal in the Software without restriction, including 9 * without limitation the rights to use, copy, modify, merge, publish, 10 * distribute, sublicense, and/or sell copies of the Software, and to 11 * permit persons to whom the Software is furnished to do so, subject to 12 * the following conditions: 13 * 14 * The above copyright notice and this permission notice shall be 15 * included in all copies or substantial portions of the Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 18 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 19 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND 20 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS 21 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN 22 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN 23 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE 24 * SOFTWARE. 25 */ 26 27#include <sys/cdefs.h> 28__KERNEL_RCSID(1, "$NetBSD: aes_ct64.c,v 1.1 2025/11/23 22:44:13 riastradh Exp $"); 29 30#include <sys/types.h> 31 32#ifdef _KERNEL 33#include <lib/libkern/libkern.h> 34#else 35#include <string.h> 36#endif 37 38#include <crypto/aes/aes_bear64.h> 39 40static void 41br_range_dec32le(uint32_t *p32, size_t nwords, const void *v) 42{ 43 const uint8_t *p8 = v; 44 45 while (nwords --> 0) { 46 uint32_t x0 = *p8++; 47 uint32_t x1 = *p8++; 48 uint32_t x2 = *p8++; 49 uint32_t x3 = *p8++; 50 51 *p32++ = x0 | (x1 << 8) | (x2 << 16) | (x3 << 24); 52 } 53} 54 55/* see inner.h */ 56void 57br_aes_ct64_bitslice_Sbox(uint64_t q[static 8]) 58{ 59 /* 60 * This S-box implementation is a straightforward translation of 61 * the circuit described by Boyar and Peralta in "A new 62 * combinational logic minimization technique with applications 63 * to cryptology" (https://eprint.iacr.org/2009/191.pdf). 64 * 65 * Note that variables x* (input) and s* (output) are numbered 66 * in "reverse" order (x0 is the high bit, x7 is the low bit). 67 */ 68 69 uint64_t x0, x1, x2, x3, x4, x5, x6, x7; 70 uint64_t y1, y2, y3, y4, y5, y6, y7, y8, y9; 71 uint64_t y10, y11, y12, y13, y14, y15, y16, y17, y18, y19; 72 uint64_t y20, y21; 73 uint64_t z0, z1, z2, z3, z4, z5, z6, z7, z8, z9; 74 uint64_t z10, z11, z12, z13, z14, z15, z16, z17; 75 uint64_t t0, t1, t2, t3, t4, t5, t6, t7, t8, t9; 76 uint64_t t10, t11, t12, t13, t14, t15, t16, t17, t18, t19; 77 uint64_t t20, t21, t22, t23, t24, t25, t26, t27, t28, t29; 78 uint64_t t30, t31, t32, t33, t34, t35, t36, t37, t38, t39; 79 uint64_t t40, t41, t42, t43, t44, t45, t46, t47, t48, t49; 80 uint64_t t50, t51, t52, t53, t54, t55, t56, t57, t58, t59; 81 uint64_t t60, t61, t62, t63, t64, t65, t66, t67; 82 uint64_t s0, s1, s2, s3, s4, s5, s6, s7; 83 84 x0 = q[7]; 85 x1 = q[6]; 86 x2 = q[5]; 87 x3 = q[4]; 88 x4 = q[3]; 89 x5 = q[2]; 90 x6 = q[1]; 91 x7 = q[0]; 92 93 /* 94 * Top linear transformation. 95 */ 96 y14 = x3 ^ x5; 97 y13 = x0 ^ x6; 98 y9 = x0 ^ x3; 99 y8 = x0 ^ x5; 100 t0 = x1 ^ x2; 101 y1 = t0 ^ x7; 102 y4 = y1 ^ x3; 103 y12 = y13 ^ y14; 104 y2 = y1 ^ x0; 105 y5 = y1 ^ x6; 106 y3 = y5 ^ y8; 107 t1 = x4 ^ y12; 108 y15 = t1 ^ x5; 109 y20 = t1 ^ x1; 110 y6 = y15 ^ x7; 111 y10 = y15 ^ t0; 112 y11 = y20 ^ y9; 113 y7 = x7 ^ y11; 114 y17 = y10 ^ y11; 115 y19 = y10 ^ y8; 116 y16 = t0 ^ y11; 117 y21 = y13 ^ y16; 118 y18 = x0 ^ y16; 119 120 /* 121 * Non-linear section. 122 */ 123 t2 = y12 & y15; 124 t3 = y3 & y6; 125 t4 = t3 ^ t2; 126 t5 = y4 & x7; 127 t6 = t5 ^ t2; 128 t7 = y13 & y16; 129 t8 = y5 & y1; 130 t9 = t8 ^ t7; 131 t10 = y2 & y7; 132 t11 = t10 ^ t7; 133 t12 = y9 & y11; 134 t13 = y14 & y17; 135 t14 = t13 ^ t12; 136 t15 = y8 & y10; 137 t16 = t15 ^ t12; 138 t17 = t4 ^ t14; 139 t18 = t6 ^ t16; 140 t19 = t9 ^ t14; 141 t20 = t11 ^ t16; 142 t21 = t17 ^ y20; 143 t22 = t18 ^ y19; 144 t23 = t19 ^ y21; 145 t24 = t20 ^ y18; 146 147 t25 = t21 ^ t22; 148 t26 = t21 & t23; 149 t27 = t24 ^ t26; 150 t28 = t25 & t27; 151 t29 = t28 ^ t22; 152 t30 = t23 ^ t24; 153 t31 = t22 ^ t26; 154 t32 = t31 & t30; 155 t33 = t32 ^ t24; 156 t34 = t23 ^ t33; 157 t35 = t27 ^ t33; 158 t36 = t24 & t35; 159 t37 = t36 ^ t34; 160 t38 = t27 ^ t36; 161 t39 = t29 & t38; 162 t40 = t25 ^ t39; 163 164 t41 = t40 ^ t37; 165 t42 = t29 ^ t33; 166 t43 = t29 ^ t40; 167 t44 = t33 ^ t37; 168 t45 = t42 ^ t41; 169 z0 = t44 & y15; 170 z1 = t37 & y6; 171 z2 = t33 & x7; 172 z3 = t43 & y16; 173 z4 = t40 & y1; 174 z5 = t29 & y7; 175 z6 = t42 & y11; 176 z7 = t45 & y17; 177 z8 = t41 & y10; 178 z9 = t44 & y12; 179 z10 = t37 & y3; 180 z11 = t33 & y4; 181 z12 = t43 & y13; 182 z13 = t40 & y5; 183 z14 = t29 & y2; 184 z15 = t42 & y9; 185 z16 = t45 & y14; 186 z17 = t41 & y8; 187 188 /* 189 * Bottom linear transformation. 190 */ 191 t46 = z15 ^ z16; 192 t47 = z10 ^ z11; 193 t48 = z5 ^ z13; 194 t49 = z9 ^ z10; 195 t50 = z2 ^ z12; 196 t51 = z2 ^ z5; 197 t52 = z7 ^ z8; 198 t53 = z0 ^ z3; 199 t54 = z6 ^ z7; 200 t55 = z16 ^ z17; 201 t56 = z12 ^ t48; 202 t57 = t50 ^ t53; 203 t58 = z4 ^ t46; 204 t59 = z3 ^ t54; 205 t60 = t46 ^ t57; 206 t61 = z14 ^ t57; 207 t62 = t52 ^ t58; 208 t63 = t49 ^ t58; 209 t64 = z4 ^ t59; 210 t65 = t61 ^ t62; 211 t66 = z1 ^ t63; 212 s0 = t59 ^ t63; 213 s6 = t56 ^ ~t62; 214 s7 = t48 ^ ~t60; 215 t67 = t64 ^ t65; 216 s3 = t53 ^ t66; 217 s4 = t51 ^ t66; 218 s5 = t47 ^ t65; 219 s1 = t64 ^ ~s3; 220 s2 = t55 ^ ~t67; 221 222 q[7] = s0; 223 q[6] = s1; 224 q[5] = s2; 225 q[4] = s3; 226 q[3] = s4; 227 q[2] = s5; 228 q[1] = s6; 229 q[0] = s7; 230} 231 232/* see inner.h */ 233void 234br_aes_ct64_ortho(uint64_t q[static 8]) 235{ 236#define SWAPN(cl, ch, s, x, y) do { \ 237 uint64_t a, b; \ 238 a = (x); \ 239 b = (y); \ 240 (x) = (a & (uint64_t)cl) | ((b & (uint64_t)cl) << (s)); \ 241 (y) = ((a & (uint64_t)ch) >> (s)) | (b & (uint64_t)ch); \ 242 } while (0) 243 244#define SWAP2(x, y) SWAPN(0x5555555555555555, 0xAAAAAAAAAAAAAAAA, 1, x, y) 245#define SWAP4(x, y) SWAPN(0x3333333333333333, 0xCCCCCCCCCCCCCCCC, 2, x, y) 246#define SWAP8(x, y) SWAPN(0x0F0F0F0F0F0F0F0F, 0xF0F0F0F0F0F0F0F0, 4, x, y) 247 248 SWAP2(q[0], q[1]); 249 SWAP2(q[2], q[3]); 250 SWAP2(q[4], q[5]); 251 SWAP2(q[6], q[7]); 252 253 SWAP4(q[0], q[2]); 254 SWAP4(q[1], q[3]); 255 SWAP4(q[4], q[6]); 256 SWAP4(q[5], q[7]); 257 258 SWAP8(q[0], q[4]); 259 SWAP8(q[1], q[5]); 260 SWAP8(q[2], q[6]); 261 SWAP8(q[3], q[7]); 262} 263 264/* see inner.h */ 265void 266br_aes_ct64_interleave_in(uint64_t q0[static 1], uint64_t q1[static 1], 267 const uint32_t w[static 4]) 268{ 269 uint64_t x0, x1, x2, x3; 270 271 x0 = w[0]; 272 x1 = w[1]; 273 x2 = w[2]; 274 x3 = w[3]; 275 x0 |= (x0 << 16); 276 x1 |= (x1 << 16); 277 x2 |= (x2 << 16); 278 x3 |= (x3 << 16); 279 x0 &= (uint64_t)0x0000FFFF0000FFFF; 280 x1 &= (uint64_t)0x0000FFFF0000FFFF; 281 x2 &= (uint64_t)0x0000FFFF0000FFFF; 282 x3 &= (uint64_t)0x0000FFFF0000FFFF; 283 x0 |= (x0 << 8); 284 x1 |= (x1 << 8); 285 x2 |= (x2 << 8); 286 x3 |= (x3 << 8); 287 x0 &= (uint64_t)0x00FF00FF00FF00FF; 288 x1 &= (uint64_t)0x00FF00FF00FF00FF; 289 x2 &= (uint64_t)0x00FF00FF00FF00FF; 290 x3 &= (uint64_t)0x00FF00FF00FF00FF; 291 *q0 = x0 | (x2 << 8); 292 *q1 = x1 | (x3 << 8); 293} 294 295/* see inner.h */ 296void 297br_aes_ct64_interleave_out(uint32_t w[static 4], uint64_t q0, uint64_t q1) 298{ 299 uint64_t x0, x1, x2, x3; 300 301 x0 = q0 & (uint64_t)0x00FF00FF00FF00FF; 302 x1 = q1 & (uint64_t)0x00FF00FF00FF00FF; 303 x2 = (q0 >> 8) & (uint64_t)0x00FF00FF00FF00FF; 304 x3 = (q1 >> 8) & (uint64_t)0x00FF00FF00FF00FF; 305 x0 |= (x0 >> 8); 306 x1 |= (x1 >> 8); 307 x2 |= (x2 >> 8); 308 x3 |= (x3 >> 8); 309 x0 &= (uint64_t)0x0000FFFF0000FFFF; 310 x1 &= (uint64_t)0x0000FFFF0000FFFF; 311 x2 &= (uint64_t)0x0000FFFF0000FFFF; 312 x3 &= (uint64_t)0x0000FFFF0000FFFF; 313 w[0] = (uint32_t)x0 | (uint32_t)(x0 >> 16); 314 w[1] = (uint32_t)x1 | (uint32_t)(x1 >> 16); 315 w[2] = (uint32_t)x2 | (uint32_t)(x2 >> 16); 316 w[3] = (uint32_t)x3 | (uint32_t)(x3 >> 16); 317} 318 319static const unsigned char Rcon[] = { 320 0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1B, 0x36 321}; 322 323static uint32_t 324sub_word(uint32_t x) 325{ 326 uint64_t q[8]; 327 328 memset(q, 0, sizeof q); 329 q[0] = x; 330 br_aes_ct64_ortho(q); 331 br_aes_ct64_bitslice_Sbox(q); 332 br_aes_ct64_ortho(q); 333 return (uint32_t)q[0]; 334} 335 336/* see inner.h */ 337unsigned 338br_aes_ct64_keysched(uint64_t comp_skey[static 30], 339 const void *key, size_t key_len) 340{ 341 unsigned num_rounds; 342 int i, j, k, nk, nkf; 343 uint32_t tmp; 344 uint32_t skey[60]; 345 346 switch (key_len) { 347 case 16: 348 num_rounds = 10; 349 break; 350 case 24: 351 num_rounds = 12; 352 break; 353 case 32: 354 num_rounds = 14; 355 break; 356 default: 357 /* abort(); */ 358 return 0; 359 } 360 nk = (int)(key_len >> 2); 361 nkf = (int)((num_rounds + 1) << 2); 362 br_range_dec32le(skey, (key_len >> 2), key); 363 tmp = skey[(key_len >> 2) - 1]; 364 for (i = nk, j = 0, k = 0; i < nkf; i ++) { 365 if (j == 0) { 366 tmp = (tmp << 24) | (tmp >> 8); 367 tmp = sub_word(tmp) ^ Rcon[k]; 368 } else if (nk > 6 && j == 4) { 369 tmp = sub_word(tmp); 370 } 371 tmp ^= skey[i - nk]; 372 skey[i] = tmp; 373 if (++ j == nk) { 374 j = 0; 375 k ++; 376 } 377 } 378 379 for (i = 0, j = 0; i < nkf; i += 4, j += 2) { 380 uint64_t q[8]; 381 382 br_aes_ct64_interleave_in(&q[0], &q[4], skey + i); 383 q[1] = q[0]; 384 q[2] = q[0]; 385 q[3] = q[0]; 386 q[5] = q[4]; 387 q[6] = q[4]; 388 q[7] = q[4]; 389 br_aes_ct64_ortho(q); 390 comp_skey[j + 0] = 391 (q[0] & (uint64_t)0x1111111111111111) 392 | (q[1] & (uint64_t)0x2222222222222222) 393 | (q[2] & (uint64_t)0x4444444444444444) 394 | (q[3] & (uint64_t)0x8888888888888888); 395 comp_skey[j + 1] = 396 (q[4] & (uint64_t)0x1111111111111111) 397 | (q[5] & (uint64_t)0x2222222222222222) 398 | (q[6] & (uint64_t)0x4444444444444444) 399 | (q[7] & (uint64_t)0x8888888888888888); 400 } 401 return num_rounds; 402} 403 404/* see inner.h */ 405void 406br_aes_ct64_skey_expand(uint64_t skey[static 120], 407 unsigned num_rounds, const uint64_t comp_skey[static 30]) 408{ 409 unsigned u, v, n; 410 411 n = (num_rounds + 1) << 1; 412 for (u = 0, v = 0; u < n; u ++, v += 4) { 413 uint64_t x0, x1, x2, x3; 414 415 x0 = x1 = x2 = x3 = comp_skey[u]; 416 x0 &= (uint64_t)0x1111111111111111; 417 x1 &= (uint64_t)0x2222222222222222; 418 x2 &= (uint64_t)0x4444444444444444; 419 x3 &= (uint64_t)0x8888888888888888; 420 x1 >>= 1; 421 x2 >>= 2; 422 x3 >>= 3; 423 skey[v + 0] = (x0 << 4) - x0; 424 skey[v + 1] = (x1 << 4) - x1; 425 skey[v + 2] = (x2 << 4) - x2; 426 skey[v + 3] = (x3 << 4) - x3; 427 } 428} 429 430/* NetBSD additions, for computing the standard AES key schedule */ 431 432unsigned 433br_aes_ct64_keysched_stdenc(uint32_t *skey, const void *key, size_t key_len) 434{ 435 unsigned num_rounds; 436 int i, j, k, nk, nkf; 437 uint32_t tmp; 438 439 switch (key_len) { 440 case 16: 441 num_rounds = 10; 442 break; 443 case 24: 444 num_rounds = 12; 445 break; 446 case 32: 447 num_rounds = 14; 448 break; 449 default: 450 /* abort(); */ 451 return 0; 452 } 453 nk = (int)(key_len >> 2); 454 nkf = (int)((num_rounds + 1) << 2); 455 tmp = 0; 456 for (i = 0; i < nk; i ++) { 457 tmp = br_dec32le((const unsigned char *)key + (i << 2)); 458 skey[i] = tmp; 459 } 460 for (i = nk, j = 0, k = 0; i < nkf; i ++) { 461 if (j == 0) { 462 tmp = (tmp << 24) | (tmp >> 8); 463 tmp = sub_word(tmp) ^ Rcon[k]; 464 } else if (nk > 6 && j == 4) { 465 tmp = sub_word(tmp); 466 } 467 tmp ^= skey[i - nk]; 468 skey[i] = tmp; 469 if (++ j == nk) { 470 j = 0; 471 k ++; 472 } 473 } 474 return num_rounds; 475} 476 477unsigned 478br_aes_ct64_keysched_stddec(uint32_t *skey, const void *key, size_t key_len) 479{ 480 uint32_t tkey[60]; 481 uint64_t q[8]; 482 unsigned num_rounds; 483 unsigned i; 484 485 num_rounds = br_aes_ct64_keysched_stdenc(skey, key, key_len); 486 if (num_rounds == 0) 487 return 0; 488 489 q[1] = q[2] = q[3] = 0; 490 q[5] = q[6] = q[7] = 0; 491 492 tkey[0] = skey[4*num_rounds + 0]; 493 tkey[1] = skey[4*num_rounds + 1]; 494 tkey[2] = skey[4*num_rounds + 2]; 495 tkey[3] = skey[4*num_rounds + 3]; 496 for (i = 1; i < num_rounds; i++) { 497 br_aes_ct64_interleave_in(&q[0], &q[4], skey + 4*i); 498 br_aes_ct64_ortho(q); 499 br_aes_ct64_inv_mix_columns(q); 500 br_aes_ct64_ortho(q); 501 br_aes_ct64_interleave_out(&tkey[4*(num_rounds - i)], 502 q[0], q[4]); 503 } 504 tkey[4*num_rounds + 0] = skey[0]; 505 tkey[4*num_rounds + 1] = skey[1]; 506 tkey[4*num_rounds + 2] = skey[2]; 507 tkey[4*num_rounds + 3] = skey[3]; 508 509 memcpy(skey, tkey, 4*(num_rounds + 1)*sizeof(uint32_t)); 510 explicit_memset(tkey, 0, 4*(num_rounds + 1)*sizeof(uint32_t)); 511 return num_rounds; 512} 513