crypto/aegis128-core.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * The AEGIS-128 Authenticated-Encryption Algorithm
   4  *
   5  * Copyright (c) 2017-2018 Ondrej Mosnacek <omosnacek@gmail.com>
   6  * Copyright (C) 2017-2018 Red Hat, Inc. All rights reserved.
   7  */
   8
   9 #include <crypto/algapi.h>
  10 #include <crypto/internal/aead.h>
  11 #include <crypto/internal/simd.h>
  12 #include <crypto/internal/skcipher.h>
  13 #include <crypto/scatterwalk.h>
  14 #include <linux/err.h>
  15 #include <linux/init.h>
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/scatterlist.h>
  19
  20 #include <asm/simd.h>
  21
  22 #include "aegis.h"
  23
  24 #define AEGIS128_NONCE_SIZE 16
  25 #define AEGIS128_STATE_BLOCKS 5
  26 #define AEGIS128_KEY_SIZE 16
  27 #define AEGIS128_MIN_AUTH_SIZE 8
  28 #define AEGIS128_MAX_AUTH_SIZE 16
  29
  30 struct aegis_state {
  31         union aegis_block blocks[AEGIS128_STATE_BLOCKS];
  32 };
  33
  34 struct aegis_ctx {
  35         union aegis_block key;
  36 };
  37
  38 struct aegis128_ops {
  39         int (*skcipher_walk_init)(struct skcipher_walk *walk,
  40                                   struct aead_request *req, bool atomic);
  41
  42         void (*crypt_chunk)(struct aegis_state *state, u8 *dst,
  43                             const u8 *src, unsigned int size);
  44 };
  45
  46 static bool have_simd;
  47
  48 static const union aegis_block crypto_aegis_const[2] = {
  49         { .words64 = {
  50                 cpu_to_le64(U64_C(0x0d08050302010100)),
  51                 cpu_to_le64(U64_C(0x6279e99059372215)),
  52         } },
  53         { .words64 = {
  54                 cpu_to_le64(U64_C(0xf12fc26d55183ddb)),
  55                 cpu_to_le64(U64_C(0xdd28b57342311120)),
  56         } },
  57 };
  58
  59 static bool aegis128_do_simd(void)
  60 {
  61 #ifdef CONFIG_CRYPTO_AEGIS128_SIMD
  62         if (have_simd)
  63                 return crypto_simd_usable();
  64 #endif
  65         return false;
  66 }
  67
  68 bool crypto_aegis128_have_simd(void);
  69 void crypto_aegis128_update_simd(struct aegis_state *state, const void *msg);
  70 void crypto_aegis128_encrypt_chunk_simd(struct aegis_state *state, u8 *dst,
  71                                         const u8 *src, unsigned int size);
  72 void crypto_aegis128_decrypt_chunk_simd(struct aegis_state *state, u8 *dst,
  73                                         const u8 *src, unsigned int size);
  74
  75 static void crypto_aegis128_update(struct aegis_state *state)
  76 {
  77         union aegis_block tmp;
  78         unsigned int i;
  79
  80         tmp = state->blocks[AEGIS128_STATE_BLOCKS - 1];
  81         for (i = AEGIS128_STATE_BLOCKS - 1; i > 0; i--)
  82                 crypto_aegis_aesenc(&state->blocks[i], &state->blocks[i - 1],
  83                                     &state->blocks[i]);
  84         crypto_aegis_aesenc(&state->blocks[0], &tmp, &state->blocks[0]);
  85 }
  86
  87 static void crypto_aegis128_update_a(struct aegis_state *state,
  88                                      const union aegis_block *msg)
  89 {
  90         if (aegis128_do_simd()) {
  91                 crypto_aegis128_update_simd(state, msg);
  92                 return;
  93         }
  94
  95         crypto_aegis128_update(state);
  96         crypto_aegis_block_xor(&state->blocks[0], msg);
  97 }
  98
  99 static void crypto_aegis128_update_u(struct aegis_state *state, const void *msg)
 100 {
 101         if (aegis128_do_simd()) {
 102                 crypto_aegis128_update_simd(state, msg);
 103                 return;
 104         }
 105
 106         crypto_aegis128_update(state);
 107         crypto_xor(state->blocks[0].bytes, msg, AEGIS_BLOCK_SIZE);
 108 }
 109
 110 static void crypto_aegis128_init(struct aegis_state *state,
 111                                  const union aegis_block *key,
 112                                  const u8 *iv)
 113 {
 114         union aegis_block key_iv;
 115         unsigned int i;
 116
 117         key_iv = *key;
 118         crypto_xor(key_iv.bytes, iv, AEGIS_BLOCK_SIZE);
 119
 120         state->blocks[0] = key_iv;
 121         state->blocks[1] = crypto_aegis_const[1];
 122         state->blocks[2] = crypto_aegis_const[0];
 123         state->blocks[3] = *key;
 124         state->blocks[4] = *key;
 125
 126         crypto_aegis_block_xor(&state->blocks[3], &crypto_aegis_const[0]);
 127         crypto_aegis_block_xor(&state->blocks[4], &crypto_aegis_const[1]);
 128
 129         for (i = 0; i < 5; i++) {
 130                 crypto_aegis128_update_a(state, key);
 131                 crypto_aegis128_update_a(state, &key_iv);
 132         }
 133 }
 134
 135 static void crypto_aegis128_ad(struct aegis_state *state,
 136                                const u8 *src, unsigned int size)
 137 {
 138         if (AEGIS_ALIGNED(src)) {
 139                 const union aegis_block *src_blk =
 140                                 (const union aegis_block *)src;
 141
 142                 while (size >= AEGIS_BLOCK_SIZE) {
 143                         crypto_aegis128_update_a(state, src_blk);
 144
 145                         size -= AEGIS_BLOCK_SIZE;
 146                         src_blk++;
 147                 }
 148         } else {
 149                 while (size >= AEGIS_BLOCK_SIZE) {
 150                         crypto_aegis128_update_u(state, src);
 151
 152                         size -= AEGIS_BLOCK_SIZE;
 153                         src += AEGIS_BLOCK_SIZE;
 154                 }
 155         }
 156 }
 157
 158 static void crypto_aegis128_encrypt_chunk(struct aegis_state *state, u8 *dst,
 159                                           const u8 *src, unsigned int size)
 160 {
 161         union aegis_block tmp;
 162
 163         if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) {
 164                 while (size >= AEGIS_BLOCK_SIZE) {
 165                         union aegis_block *dst_blk =
 166                                         (union aegis_block *)dst;
 167                         const union aegis_block *src_blk =
 168                                         (const union aegis_block *)src;
 169
 170                         tmp = state->blocks[2];
 171                         crypto_aegis_block_and(&tmp, &state->blocks[3]);
 172                         crypto_aegis_block_xor(&tmp, &state->blocks[4]);
 173                         crypto_aegis_block_xor(&tmp, &state->blocks[1]);
 174                         crypto_aegis_block_xor(&tmp, src_blk);
 175
 176                         crypto_aegis128_update_a(state, src_blk);
 177
 178                         *dst_blk = tmp;
 179
 180                         size -= AEGIS_BLOCK_SIZE;
 181                         src += AEGIS_BLOCK_SIZE;
 182                         dst += AEGIS_BLOCK_SIZE;
 183                 }
 184         } else {
 185                 while (size >= AEGIS_BLOCK_SIZE) {
 186                         tmp = state->blocks[2];
 187                         crypto_aegis_block_and(&tmp, &state->blocks[3]);
 188                         crypto_aegis_block_xor(&tmp, &state->blocks[4]);
 189                         crypto_aegis_block_xor(&tmp, &state->blocks[1]);
 190                         crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE);
 191
 192                         crypto_aegis128_update_u(state, src);
 193
 194                         memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE);
 195
 196                         size -= AEGIS_BLOCK_SIZE;
 197                         src += AEGIS_BLOCK_SIZE;
 198                         dst += AEGIS_BLOCK_SIZE;
 199                 }
 200         }
 201
 202         if (size > 0) {
 203                 union aegis_block msg = {};
 204                 memcpy(msg.bytes, src, size);
 205
 206                 tmp = state->blocks[2];
 207                 crypto_aegis_block_and(&tmp, &state->blocks[3]);
 208                 crypto_aegis_block_xor(&tmp, &state->blocks[4]);
 209                 crypto_aegis_block_xor(&tmp, &state->blocks[1]);
 210
 211                 crypto_aegis128_update_a(state, &msg);
 212
 213                 crypto_aegis_block_xor(&msg, &tmp);
 214
 215                 memcpy(dst, msg.bytes, size);
 216         }
 217 }
 218
 219 static void crypto_aegis128_decrypt_chunk(struct aegis_state *state, u8 *dst,
 220                                           const u8 *src, unsigned int size)
 221 {
 222         union aegis_block tmp;
 223
 224         if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) {
 225                 while (size >= AEGIS_BLOCK_SIZE) {
 226                         union aegis_block *dst_blk =
 227                                         (union aegis_block *)dst;
 228                         const union aegis_block *src_blk =
 229                                         (const union aegis_block *)src;
 230
 231                         tmp = state->blocks[2];
 232                         crypto_aegis_block_and(&tmp, &state->blocks[3]);
 233                         crypto_aegis_block_xor(&tmp, &state->blocks[4]);
 234                         crypto_aegis_block_xor(&tmp, &state->blocks[1]);
 235                         crypto_aegis_block_xor(&tmp, src_blk);
 236
 237                         crypto_aegis128_update_a(state, &tmp);
 238
 239                         *dst_blk = tmp;
 240
 241                         size -= AEGIS_BLOCK_SIZE;
 242                         src += AEGIS_BLOCK_SIZE;
 243                         dst += AEGIS_BLOCK_SIZE;
 244                 }
 245         } else {
 246                 while (size >= AEGIS_BLOCK_SIZE) {
 247                         tmp = state->blocks[2];
 248                         crypto_aegis_block_and(&tmp, &state->blocks[3]);
 249                         crypto_aegis_block_xor(&tmp, &state->blocks[4]);
 250                         crypto_aegis_block_xor(&tmp, &state->blocks[1]);
 251                         crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE);
 252
 253                         crypto_aegis128_update_a(state, &tmp);
 254
 255                         memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE);
 256
 257                         size -= AEGIS_BLOCK_SIZE;
 258                         src += AEGIS_BLOCK_SIZE;
 259                         dst += AEGIS_BLOCK_SIZE;
 260                 }
 261         }
 262
 263         if (size > 0) {
 264                 union aegis_block msg = {};
 265                 memcpy(msg.bytes, src, size);
 266
 267                 tmp = state->blocks[2];
 268                 crypto_aegis_block_and(&tmp, &state->blocks[3]);
 269                 crypto_aegis_block_xor(&tmp, &state->blocks[4]);
 270                 crypto_aegis_block_xor(&tmp, &state->blocks[1]);
 271                 crypto_aegis_block_xor(&msg, &tmp);
 272
 273                 memset(msg.bytes + size, 0, AEGIS_BLOCK_SIZE - size);
 274
 275                 crypto_aegis128_update_a(state, &msg);
 276
 277                 memcpy(dst, msg.bytes, size);
 278         }
 279 }
 280
 281 static void crypto_aegis128_process_ad(struct aegis_state *state,
 282                                        struct scatterlist *sg_src,
 283                                        unsigned int assoclen)
 284 {
 285         struct scatter_walk walk;
 286         union aegis_block buf;
 287         unsigned int pos = 0;
 288
 289         scatterwalk_start(&walk, sg_src);
 290         while (assoclen != 0) {
 291                 unsigned int size = scatterwalk_clamp(&walk, assoclen);
 292                 unsigned int left = size;
 293                 void *mapped = scatterwalk_map(&walk);
 294                 const u8 *src = (const u8 *)mapped;
 295
 296                 if (pos + size >= AEGIS_BLOCK_SIZE) {
 297                         if (pos > 0) {
 298                                 unsigned int fill = AEGIS_BLOCK_SIZE - pos;
 299                                 memcpy(buf.bytes + pos, src, fill);
 300                                 crypto_aegis128_update_a(state, &buf);
 301                                 pos = 0;
 302                                 left -= fill;
 303                                 src += fill;
 304                         }
 305
 306                         crypto_aegis128_ad(state, src, left);
 307                         src += left & ~(AEGIS_BLOCK_SIZE - 1);
 308                         left &= AEGIS_BLOCK_SIZE - 1;
 309                 }
 310
 311                 memcpy(buf.bytes + pos, src, left);
 312
 313                 pos += left;
 314                 assoclen -= size;
 315                 scatterwalk_unmap(mapped);
 316                 scatterwalk_advance(&walk, size);
 317                 scatterwalk_done(&walk, 0, assoclen);
 318         }
 319
 320         if (pos > 0) {
 321                 memset(buf.bytes + pos, 0, AEGIS_BLOCK_SIZE - pos);
 322                 crypto_aegis128_update_a(state, &buf);
 323         }
 324 }
 325
 326 static void crypto_aegis128_process_crypt(struct aegis_state *state,
 327                                           struct aead_request *req,
 328                                           const struct aegis128_ops *ops)
 329 {
 330         struct skcipher_walk walk;
 331
 332         ops->skcipher_walk_init(&walk, req, false);
 333
 334         while (walk.nbytes) {
 335                 unsigned int nbytes = walk.nbytes;
 336
 337                 if (nbytes < walk.total)
 338                         nbytes = round_down(nbytes, walk.stride);
 339
 340                 ops->crypt_chunk(state, walk.dst.virt.addr, walk.src.virt.addr,
 341                                  nbytes);
 342
 343                 skcipher_walk_done(&walk, walk.nbytes - nbytes);
 344         }
 345 }
 346
 347 static void crypto_aegis128_final(struct aegis_state *state,
 348                                   union aegis_block *tag_xor,
 349                                   u64 assoclen, u64 cryptlen)
 350 {
 351         u64 assocbits = assoclen * 8;
 352         u64 cryptbits = cryptlen * 8;
 353
 354         union aegis_block tmp;
 355         unsigned int i;
 356
 357         tmp.words64[0] = cpu_to_le64(assocbits);
 358         tmp.words64[1] = cpu_to_le64(cryptbits);
 359
 360         crypto_aegis_block_xor(&tmp, &state->blocks[3]);
 361
 362         for (i = 0; i < 7; i++)
 363                 crypto_aegis128_update_a(state, &tmp);
 364
 365         for (i = 0; i < AEGIS128_STATE_BLOCKS; i++)
 366                 crypto_aegis_block_xor(tag_xor, &state->blocks[i]);
 367 }
 368
 369 static int crypto_aegis128_setkey(struct crypto_aead *aead, const u8 *key,
 370                                   unsigned int keylen)
 371 {
 372         struct aegis_ctx *ctx = crypto_aead_ctx(aead);
 373
 374         if (keylen != AEGIS128_KEY_SIZE) {
 375                 crypto_aead_set_flags(aead, CRYPTO_TFM_RES_BAD_KEY_LEN);
 376                 return -EINVAL;
 377         }
 378
 379         memcpy(ctx->key.bytes, key, AEGIS128_KEY_SIZE);
 380         return 0;
 381 }
 382
 383 static int crypto_aegis128_setauthsize(struct crypto_aead *tfm,
 384                                        unsigned int authsize)
 385 {
 386         if (authsize > AEGIS128_MAX_AUTH_SIZE)
 387                 return -EINVAL;
 388         if (authsize < AEGIS128_MIN_AUTH_SIZE)
 389                 return -EINVAL;
 390         return 0;
 391 }
 392
 393 static void crypto_aegis128_crypt(struct aead_request *req,
 394                                   union aegis_block *tag_xor,
 395                                   unsigned int cryptlen,
 396                                   const struct aegis128_ops *ops)
 397 {
 398         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 399         struct aegis_ctx *ctx = crypto_aead_ctx(tfm);
 400         struct aegis_state state;
 401
 402         crypto_aegis128_init(&state, &ctx->key, req->iv);
 403         crypto_aegis128_process_ad(&state, req->src, req->assoclen);
 404         crypto_aegis128_process_crypt(&state, req, ops);
 405         crypto_aegis128_final(&state, tag_xor, req->assoclen, cryptlen);
 406 }
 407
 408 static int crypto_aegis128_encrypt(struct aead_request *req)
 409 {
 410         const struct aegis128_ops *ops = &(struct aegis128_ops){
 411                 .skcipher_walk_init = skcipher_walk_aead_encrypt,
 412                 .crypt_chunk = crypto_aegis128_encrypt_chunk,
 413         };
 414
 415         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 416         union aegis_block tag = {};
 417         unsigned int authsize = crypto_aead_authsize(tfm);
 418         unsigned int cryptlen = req->cryptlen;
 419
 420         if (aegis128_do_simd())
 421                 ops = &(struct aegis128_ops){
 422                         .skcipher_walk_init = skcipher_walk_aead_encrypt,
 423                         .crypt_chunk = crypto_aegis128_encrypt_chunk_simd };
 424
 425         crypto_aegis128_crypt(req, &tag, cryptlen, ops);
 426
 427         scatterwalk_map_and_copy(tag.bytes, req->dst, req->assoclen + cryptlen,
 428                                  authsize, 1);
 429         return 0;
 430 }
 431
 432 static int crypto_aegis128_decrypt(struct aead_request *req)
 433 {
 434         const struct aegis128_ops *ops = &(struct aegis128_ops){
 435                 .skcipher_walk_init = skcipher_walk_aead_decrypt,
 436                 .crypt_chunk = crypto_aegis128_decrypt_chunk,
 437         };
 438         static const u8 zeros[AEGIS128_MAX_AUTH_SIZE] = {};
 439
 440         struct crypto_aead *tfm = crypto_aead_reqtfm(req);
 441         union aegis_block tag;
 442         unsigned int authsize = crypto_aead_authsize(tfm);
 443         unsigned int cryptlen = req->cryptlen - authsize;
 444
 445         scatterwalk_map_and_copy(tag.bytes, req->src, req->assoclen + cryptlen,
 446                                  authsize, 0);
 447
 448         if (aegis128_do_simd())
 449                 ops = &(struct aegis128_ops){
 450                         .skcipher_walk_init = skcipher_walk_aead_decrypt,
 451                         .crypt_chunk = crypto_aegis128_decrypt_chunk_simd };
 452
 453         crypto_aegis128_crypt(req, &tag, cryptlen, ops);
 454
 455         return crypto_memneq(tag.bytes, zeros, authsize) ? -EBADMSG : 0;
 456 }
 457
 458 static struct aead_alg crypto_aegis128_alg = {
 459         .setkey = crypto_aegis128_setkey,
 460         .setauthsize = crypto_aegis128_setauthsize,
 461         .encrypt = crypto_aegis128_encrypt,
 462         .decrypt = crypto_aegis128_decrypt,
 463
 464         .ivsize = AEGIS128_NONCE_SIZE,
 465         .maxauthsize = AEGIS128_MAX_AUTH_SIZE,
 466         .chunksize = AEGIS_BLOCK_SIZE,
 467
 468         .base = {
 469                 .cra_blocksize = 1,
 470                 .cra_ctxsize = sizeof(struct aegis_ctx),
 471                 .cra_alignmask = 0,
 472
 473                 .cra_priority = 100,
 474
 475                 .cra_name = "aegis128",
 476                 .cra_driver_name = "aegis128-generic",
 477
 478                 .cra_module = THIS_MODULE,
 479         }
 480 };
 481
 482 static int __init crypto_aegis128_module_init(void)
 483 {
 484         if (IS_ENABLED(CONFIG_CRYPTO_AEGIS128_SIMD))
 485                 have_simd = crypto_aegis128_have_simd();
 486
 487         return crypto_register_aead(&crypto_aegis128_alg);
 488 }
 489
 490 static void __exit crypto_aegis128_module_exit(void)
 491 {
 492         crypto_unregister_aead(&crypto_aegis128_alg);
 493 }
 494
 495 subsys_initcall(crypto_aegis128_module_init);
 496 module_exit(crypto_aegis128_module_exit);
 497
 498 MODULE_LICENSE("GPL");
 499 MODULE_AUTHOR("Ondrej Mosnacek <omosnacek@gmail.com>");
 500 MODULE_DESCRIPTION("AEGIS-128 AEAD algorithm");
 501 MODULE_ALIAS_CRYPTO("aegis128");
 502 MODULE_ALIAS_CRYPTO("aegis128-generic");