crypto/morus640.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * The MORUS-640 Authenticated-Encryption Algorithm
   4  *
   5  * Copyright (c) 2016-2018 Ondrej Mosnacek <omosnacek@gmail.com>
   6  * Copyright (C) 2017-2018 Red Hat, Inc. All rights reserved.
   7  */
   8
   9 #include <asm/unaligned.h>
  10 #include <crypto/algapi.h>
  11 #include <crypto/internal/aead.h>
  12 #include <crypto/internal/skcipher.h>
  13 #include <crypto/morus_common.h>
  14 #include <crypto/scatterwalk.h>
  15 #include <linux/err.h>
  16 #include <linux/init.h>
  17 #include <linux/kernel.h>
  18 #include <linux/module.h>
  19 #include <linux/scatterlist.h>
  20
  21 #define MORUS640_WORD_SIZE 4
  22 #define MORUS640_BLOCK_SIZE (MORUS_BLOCK_WORDS * MORUS640_WORD_SIZE)
  23 #define MORUS640_BLOCK_ALIGN (__alignof__(__le32))
  24 #define MORUS640_ALIGNED(p) IS_ALIGNED((uintptr_t)p, MORUS640_BLOCK_ALIGN)
  25
  26 struct morus640_block {
  27         u32 words[MORUS_BLOCK_WORDS];
  28 };
  29
  30 union morus640_block_in {
  31         __le32 words[MORUS_BLOCK_WORDS];
  32         u8 bytes[MORUS640_BLOCK_SIZE];
  33 };
  34
  35 struct morus640_state {
  36         struct morus640_block s[MORUS_STATE_BLOCKS];
  37 };
  38
  39 struct morus640_ctx {
  40         struct morus640_block key;
  41 };
  42
  43 struct morus640_ops {
  44         int (*skcipher_walk_init)(struct skcipher_walk *walk,
  45                                   struct aead_request *req, bool atomic);
  46
  47         void (*crypt_chunk)(struct morus640_state *state,
  48                             u8 *dst, const u8 *src, unsigned int size);
  49 };
  50
  51 static const struct morus640_block crypto_morus640_const[2] = {
  52         { .words = {
  53                 U32_C(0x02010100),
  54                 U32_C(0x0d080503),
  55                 U32_C(0x59372215),
  56                 U32_C(0x6279e990),
  57         } },
  58         { .words = {
  59                 U32_C(0x55183ddb),
  60                 U32_C(0xf12fc26d),
  61                 U32_C(0x42311120),
  62                 U32_C(0xdd28b573),
  63         } },
  64 };
  65
  66 static void crypto_morus640_round(struct morus640_block *b0,
  67                                   struct morus640_block *b1,
  68                                   struct morus640_block *b2,
  69                                   struct morus640_block *b3,
  70                                   struct morus640_block *b4,
  71                                   const struct morus640_block *m,
  72                                   unsigned int b, unsigned int w)
  73 {
  74         unsigned int i;
  75         struct morus640_block tmp;
  76
  77         for (i = 0; i < MORUS_BLOCK_WORDS; i++) {
  78                 b0->words[i] ^= b1->words[i] & b2->words[i];
  79                 b0->words[i] ^= b3->words[i];
  80                 b0->words[i] ^= m->words[i];
  81                 b0->words[i] = rol32(b0->words[i], b);
  82         }
  83
  84         tmp = *b3;
  85         for (i = 0; i < MORUS_BLOCK_WORDS; i++)
  86                 b3->words[(i + w) % MORUS_BLOCK_WORDS] = tmp.words[i];
  87 }
  88
  89 static void crypto_morus640_update(struct morus640_state *state,
  90                                    const struct morus640_block *m)
  91 {
  92         static const struct morus640_block z = {};
  93
  94         struct morus640_block *s = state->s;
  95
  96         crypto_morus640_round(&s[0], &s[1], &s[2], &s[3], &s[4], &z,  5, 1);
  97         crypto_morus640_round(&s[1], &s[2], &s[3], &s[4], &s[0], m,  31, 2);
  98         crypto_morus640_round(&s[2], &s[3], &s[4], &s[0], &s[1], m,   7, 3);
  99         crypto_morus640_round(&s[3], &s[4], &s[0], &s[1], &s[2], m,  22, 2);
 100         crypto_morus640_round(&s[4], &s[0], &s[1], &s[2], &s[3], m,  13, 1);
 101 }
 102
 103 static void crypto_morus640_load_a(struct morus640_block *dst, const u8 *src)
 104 {
 105         unsigned int i;
 106         for (i = 0; i < MORUS_BLOCK_WORDS; i++) {
 107                 dst->words[i] = le32_to_cpu(*(const __le32 *)src);
 108                 src += MORUS640_WORD_SIZE;
 109         }
 110 }
 111
 112 static void crypto_morus640_load_u(struct morus640_block *dst, const u8 *src)
 113 {
 114         unsigned int i;
 115         for (i = 0; i < MORUS_BLOCK_WORDS; i++) {
 116                 dst->words[i] = get_unaligned_le32(src);
 117                 src += MORUS640_WORD_SIZE;
 118         }
 119 }
 120
 121 static void crypto_morus640_load(struct morus640_block *dst, const u8 *src)
 122 {
 123         if (MORUS640_ALIGNED(src))
 124                 crypto_morus640_load_a(dst, src);
 125         else
 126                 crypto_morus640_load_u(dst, src);
 127 }
 128
 129 static void crypto_morus640_store_a(u8 *dst, const struct morus640_block *src)
 130 {
 131         unsigned int i;
 132         for (i = 0; i < MORUS_BLOCK_WORDS; i++) {
 133                 *(__le32 *)dst = cpu_to_le32(src->words[i]);
 134                 dst += MORUS640_WORD_SIZE;
 135         }
 136 }
 137
 138 static void crypto_morus640_store_u(u8 *dst, const struct morus640_block *src)
 139 {
 140         unsigned int i;
 141         for (i = 0; i < MORUS_BLOCK_WORDS; i++) {
 142                 put_unaligned_le32(src->words[i], dst);
 143                 dst += MORUS640_WORD_SIZE;
 144         }
 145 }
 146
 147 static void crypto_morus640_store(u8 *dst, const struct morus640_block *src)
 148 {
 149         if (MORUS640_ALIGNED(dst))
 150                 crypto_morus640_store_a(dst, src);
 151         else
 152                 crypto_morus640_store_u(dst, src);
 153 }
 154
 155 static void crypto_morus640_ad(struct morus640_state *state, const u8 *src,
 156                                unsigned int size)
 157 {
 158         struct morus640_block m;
 159
 160         if (MORUS640_ALIGNED(src)) {
 161                 while (size >= MORUS640_BLOCK_SIZE) {
 162                         crypto_morus640_load_a(&m, src);
 163                         crypto_morus640_update(state, &m);
 164
 165                         size -= MORUS640_BLOCK_SIZE;
 166                         src += MORUS640_BLOCK_SIZE;
 167                 }
 168         } else {
 169                 while (size >= MORUS640_BLOCK_SIZE) {
 170                         crypto_morus640_load_u(&m, src);
 171                         crypto_morus640_update(state, &m);
 172
 173                         size -= MORUS640_BLOCK_SIZE;
 174                         src += MORUS640_BLOCK_SIZE;
 175                 }
 176         }
 177 }
 178
 179 static void crypto_morus640_core(const struct morus640_state *state,
 180                                  struct morus640_block *blk)
 181 {
 182         unsigned int i;
 183
 184         for (i = 0; i < MORUS_BLOCK_WORDS; i++)
 185                 blk->words[(i + 3) % MORUS_BLOCK_WORDS] ^= state->s[1].words[i];
 186
 187         for (i = 0; i < MORUS_BLOCK_WORDS; i++) {
 188                 blk->words[i] ^= state->s[0].words[i];
 189                 blk->words[i] ^= state->s[2].words[i] & state->s[3].words[i];
 190         }
 191 }
 192
 193 static void crypto_morus640_encrypt_chunk(struct morus640_state *state, u8 *dst,
 194                                           const u8 *src, unsigned int size)
 195 {
 196         struct morus640_block c, m;
 197
 198         if (MORUS640_ALIGNED(src) && MORUS640_ALIGNED(dst)) {
 199                 while (size >= MORUS640_BLOCK_SIZE) {
 200                         crypto_morus640_load_a(&m, src);
 201                         c = m;
 202                         crypto_morus640_core(state, &c);
 203                         crypto_morus640_store_a(dst, &c);
 204                         crypto_morus640_update(state, &m);
 205
 206                         src += MORUS640_BLOCK_SIZE;
 207                         dst += MORUS640_BLOCK_SIZE;
 208                         size -= MORUS640_BLOCK_SIZE;
 209                 }
 210         } else {
 211                 while (size >= MORUS640_BLOCK_SIZE) {
 212                         crypto_morus640_load_u(&m, src);
 213                         c = m;
 214                         crypto_morus640_core(state, &c);
 215                         crypto_morus640_store_u(dst, &c);
 216                         crypto_morus640_update(state, &m);
 217
 218                         src += MORUS640_BLOCK_SIZE;
 219                         dst += MORUS640_BLOCK_SIZE;
 220                         size -= MORUS640_BLOCK_SIZE;
 221                 }
 222         }
 223
 224         if (size > 0) {
 225                 union morus640_block_in tail;
 226
 227                 memcpy(tail.bytes, src, size);
 228                 memset(tail.bytes + size, 0, MORUS640_BLOCK_SIZE - size);
 229
 230                 crypto_morus640_load_a(&m, tail.bytes);
 231                 c = m;
 232                 crypto_morus640_core(state, &c);
 233                 crypto_morus640_store_a(tail.bytes, &c);
 234                 crypto_morus640_update(state, &m);
 235
 236                 memcpy(dst, tail.bytes, size);
 237         }
 238 }
 239
 240 static void crypto_morus640_decrypt_chunk(struct morus640_state *state, u8 *dst,
 241                                           const u8 *src, unsigned int size)
 242 {
 243         struct morus640_block m;
 244
 245         if (MORUS640_ALIGNED(src) && MORUS640_ALIGNED(dst)) {
 246                 while (size >= MORUS640_BLOCK_SIZE) {
 247                         crypto_morus640_load_a(&m, src);
 248                         crypto_morus640_core(state, &m);
 249                         crypto_morus640_store_a(dst, &m);
 250                         crypto_morus640_update(state, &m);
 251
 252                         src += MORUS640_BLOCK_SIZE;
 253                         dst += MORUS640_BLOCK_SIZE;
 254                         size -= MORUS640_BLOCK_SIZE;
 255                 }
 256         } else {
 257                 while (size >= MORUS640_BLOCK_SIZE) {
 258                         crypto_morus640_load_u(&m, src);
 259                         crypto_morus640_core(state, &m);
 260                         crypto_morus640_store_u(dst, &m);
 261                         crypto_morus640_update(state, &m);
 262
 263                         src += MORUS640_BLOCK_SIZE;
 264                         dst += MORUS640_BLOCK_SIZE;
 265                         size -= MORUS640_BLOCK_SIZE;
 266                 }
 267         }
 268
 269         if (size > 0) {
 270                 union morus640_block_in tail;
 271
 272                 memcpy(tail.bytes, src, size);
 273                 memset(tail.bytes + size, 0, MORUS640_BLOCK_SIZE - size);
 274
 275                 crypto_morus640_load_a(&m, tail.bytes);
 276                 crypto_morus640_core(state, &m);
 277                 crypto_morus640_store_a(tail.bytes, &m);
 278                 memset(tail.bytes + size, 0, MORUS640_BLOCK_SIZE - size);
 279                 crypto_morus640_load_a(&m, tail.bytes);
 280                 crypto_morus640_update(state, &m);
 281
 282                 memcpy(dst, tail.bytes, size);
 283         }
 284 }
 285
 286 static void crypto_morus640_init(struct morus640_state *state,
 287                                  const struct morus640_block *key,
 288                                  const u8 *iv)
 289 {
 290         static const struct morus640_block z = {};
 291
 292         unsigned int i;
 293
 294         crypto_morus640_load(&state->s[0], iv);
 295         state->s[1] = *key;
 296         for (i = 0; i < MORUS_BLOCK_WORDS; i++)
 297                 state->s[2].words[i] = U32_C(0xFFFFFFFF);
 298         state->s[3] = crypto_morus640_const[0];
 299         state->s[4] = crypto_morus640_const[1];
 300
 301         for (i = 0; i < 16; i++)
 302                 crypto_morus640_update(state, &z);
 303
 304         for (i = 0; i < MORUS_BLOCK_WORDS; i++)
 305                 state->s[1].words[i] ^= key->words[i];
 306 }
 307
 308 static void crypto_morus640_process_ad(struct morus640_state *state,
 309                                        struct scatterlist *sg_src,
 310                                        unsigned int assoclen)
 311 {
 312         struct scatter_walk walk;
 313         struct morus640_block m;
 314         union morus640_block_in buf;
 315         unsigned int pos = 0;
 316
 317         scatterwalk_start(&walk, sg_src);
 318         while (assoclen != 0) {
 319                 unsigned int size = scatterwalk_clamp(&walk, assoclen);
 320                 unsigned int left = size;
 321                 void *mapped = scatterwalk_map(&walk);
 322                 const u8 *src = (const u8 *)mapped;
 323
 324                 if (pos + size >= MORUS640_BLOCK_SIZE) {
 325                         if (pos > 0) {
 326                                 unsigned int fill = MORUS640_BLOCK_SIZE - pos;
 327                                 memcpy(buf.bytes + pos, src, fill);
 328
 329                                 crypto_morus640_load_a(&m, buf.bytes);
 330                                 crypto_morus640_update(state, &m);
 331
 332                                 pos = 0;
 333                                 left -= fill;
 334                                 src += fill;
 335                         }
 336
 337                         crypto_morus640_ad(state, src, left);
 338                         src += left & ~(MORUS640_BLOCK_SIZE - 1);
 339                         left &= MORUS640_BLOCK_SIZE - 1;
 340                 }
 341
 342                 memcpy(buf.bytes + pos, src, left);
 343
 344                 pos += left;
 345                 assoclen -= size;
 346                 scatterwalk_unmap(mapped);
 347                 scatterwalk_advance(&walk, size);
 348                 scatterwalk_done(&walk, 0, assoclen);
 349         }
 350
 351         if (pos > 0) {
 352                 memset(buf.bytes + pos, 0, MORUS640_BLOCK_SIZE - pos);
 353
 354                 crypto_morus640_load_a(&m, buf.bytes);
 355                 crypto_morus640_update(state, &m);
 356         }
 357 }
 358
 359 static void crypto_morus640_process_crypt(struct morus640_state *state,
 360                                           struct aead_request *req,
 361                                           const struct morus640_ops *ops)
 362 {
 363         struct skcipher_walk walk;
 364
 365         ops->skcipher_walk_init(&walk, req, false);
 366
 367         while (walk.nbytes) {
 368                 unsigned int nbytes = walk.nbytes;
 369
 370                 if (nbytes < walk.total)
 371                         nbytes = round_down(nbytes, walk.stride);
 372
 373                 ops->crypt_chunk(state, walk.dst.virt.addr, walk.src.virt.addr,
 374                                  nbytes);
 375
 376                 skcipher_walk_done(&walk, walk.nbytes - nbytes);
 377         }
 378 }
 379
 380 static void crypto_morus640_final(struct morus640_state *state,
 381                                   struct morus640_block *tag_xor,
 382                                   u64 assoclen, u64 cryptlen)
 383 {
 384         struct morus640_block tmp;
 385         unsigned int i;
 386
 387         tmp.words[0] = lower_32_bits(assoclen * 8);
 388         tmp.words[1] = upper_32_bits(assoclen * 8);
 389         tmp.words[2] = lower_32_bits(cryptlen * 8);
 390         tmp.words[3] = upper_32_bits(cryptlen * 8);
 391
 392         for (i = 0; i < MORUS_BLOCK_WORDS; i++)
 393                 state->s[4].words[i] ^= state->s[0].words[i];
 394
 395         for (i = 0; i < 10; i++)
 396                 crypto_morus640_update(state, &tmp);
 397
 398         crypto_morus640_core(state, tag_xor);
 399 }
 400
 401 static int crypto_morus640_setkey(struct crypto_aead *aead, const u8 *key,
 402                                   unsigned int keylen)
 403 {
 404         struct morus640_ctx *ctx = crypto_aead_ctx(aead);
 405
 406         if (keylen != MORUS640_BLOCK_SIZE) {
 407                 crypto_aead_set_flags(aead, CRYPTO_TFM_RES_BAD_KEY_LEN);
 408                 return -EINVAL;
 409         }
 410
 411         crypto_morus640_load(&ctx->key, key);
 412         return 0;
 413 }
 414
 415 static int crypto_morus640_setauthsize(struct crypto_aead *tfm,
 416                                        unsigned int authsize)
 417 {
 418         return (authsize <= MORUS_MAX_AUTH_SIZE) ? 0 : -EINVAL;
 419 }
 420
 421 static void crypto_morus640_crypt(struct aead_request *req,
 422                                   struct morus640_block *tag_xor,
 423                                   unsigned int cryptlen,
 424                                   const struct morus640_ops *ops)
 425 {
 426         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 427         struct morus640_ctx *ctx = crypto_aead_ctx(tfm);
 428         struct morus640_state state;
 429
 430         crypto_morus640_init(&state, &ctx->key, req->iv);
 431         crypto_morus640_process_ad(&state, req->src, req->assoclen);
 432         crypto_morus640_process_crypt(&state, req, ops);
 433         crypto_morus640_final(&state, tag_xor, req->assoclen, cryptlen);
 434 }
 435
 436 static int crypto_morus640_encrypt(struct aead_request *req)
 437 {
 438         static const struct morus640_ops ops = {
 439                 .skcipher_walk_init = skcipher_walk_aead_encrypt,
 440                 .crypt_chunk = crypto_morus640_encrypt_chunk,
 441         };
 442
 443         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 444         struct morus640_block tag = {};
 445         union morus640_block_in tag_out;
 446         unsigned int authsize = crypto_aead_authsize(tfm);
 447         unsigned int cryptlen = req->cryptlen;
 448
 449         crypto_morus640_crypt(req, &tag, cryptlen, &ops);
 450         crypto_morus640_store(tag_out.bytes, &tag);
 451
 452         scatterwalk_map_and_copy(tag_out.bytes, req->dst,
 453                                  req->assoclen + cryptlen, authsize, 1);
 454         return 0;
 455 }
 456
 457 static int crypto_morus640_decrypt(struct aead_request *req)
 458 {
 459         static const struct morus640_ops ops = {
 460                 .skcipher_walk_init = skcipher_walk_aead_decrypt,
 461                 .crypt_chunk = crypto_morus640_decrypt_chunk,
 462         };
 463         static const u8 zeros[MORUS640_BLOCK_SIZE] = {};
 464
 465         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 466         union morus640_block_in tag_in;
 467         struct morus640_block tag;
 468         unsigned int authsize = crypto_aead_authsize(tfm);
 469         unsigned int cryptlen = req->cryptlen - authsize;
 470
 471         scatterwalk_map_and_copy(tag_in.bytes, req->src,
 472                                  req->assoclen + cryptlen, authsize, 0);
 473
 474         crypto_morus640_load(&tag, tag_in.bytes);
 475         crypto_morus640_crypt(req, &tag, cryptlen, &ops);
 476         crypto_morus640_store(tag_in.bytes, &tag);
 477
 478         return crypto_memneq(tag_in.bytes, zeros, authsize) ? -EBADMSG : 0;
 479 }
 480
 481 static int crypto_morus640_init_tfm(struct crypto_aead *tfm)
 482 {
 483         return 0;
 484 }
 485
 486 static void crypto_morus640_exit_tfm(struct crypto_aead *tfm)
 487 {
 488 }
 489
 490 static struct aead_alg crypto_morus640_alg = {
 491         .setkey = crypto_morus640_setkey,
 492         .setauthsize = crypto_morus640_setauthsize,
 493         .encrypt = crypto_morus640_encrypt,
 494         .decrypt = crypto_morus640_decrypt,
 495         .init = crypto_morus640_init_tfm,
 496         .exit = crypto_morus640_exit_tfm,
 497
 498         .ivsize = MORUS_NONCE_SIZE,
 499         .maxauthsize = MORUS_MAX_AUTH_SIZE,
 500         .chunksize = MORUS640_BLOCK_SIZE,
 501
 502         .base = {
 503                 .cra_blocksize = 1,
 504                 .cra_ctxsize = sizeof(struct morus640_ctx),
 505                 .cra_alignmask = 0,
 506
 507                 .cra_priority = 100,
 508
 509                 .cra_name = "morus640",
 510                 .cra_driver_name = "morus640-generic",
 511
 512                 .cra_module = THIS_MODULE,
 513         }
 514 };
 515
 516 static int __init crypto_morus640_module_init(void)
 517 {
 518         return crypto_register_aead(&crypto_morus640_alg);
 519 }
 520
 521 static void __exit crypto_morus640_module_exit(void)
 522 {
 523         crypto_unregister_aead(&crypto_morus640_alg);
 524 }
 525
 526 subsys_initcall(crypto_morus640_module_init);
 527 module_exit(crypto_morus640_module_exit);
 528
 529 MODULE_LICENSE("GPL");
 530 MODULE_AUTHOR("Ondrej Mosnacek <omosnacek@gmail.com>");
 531 MODULE_DESCRIPTION("MORUS-640 AEAD algorithm");
 532 MODULE_ALIAS_CRYPTO("morus640");
 533 MODULE_ALIAS_CRYPTO("morus640-generic");